An optical collimator is a device which collects rays from a point source of light such as a light bulb or light emitting diode and causes those rays to emerge in parallel from a surface. Examples of collimators include lenses or curved mirrors found in a flashlight or car headlamp. In these examples, a volume of space exists between the point source and the surface from which the collimated light exits. In some use environments, this space may be inconvenient, as it may increase the overall size of an optical device that utilizes the collimator.


On removing oils and the like such as machine oil, rolling oil, and rust-preventive oil attached to machines, mechanical parts, and the like, or on removing oils and the like generated during fiber-processing stage and attached to facilities, there are used in recent years a water-base cleaner consisting mainly of nonionic and anionic surfactant, and a strong-alkali cleaner combining the water-base cleaner with a strong alkali. In case of conventional cleaners which enhance the increased cleaning power and foamability, however, the water-oil separability in the cleaned waste liquid becomes insufficient to apply heavy load to the wastewater treatment, because oils form stable emulsion in the cleaned waste liquid after cleaning or because oils stably become solubilized in the cleaned waste liquid after cleaning. Current serious concern about the environmental problems raises the requirement of reducing the quantity of waste liquid generated from the water-oil separation treatment and of recycling the cleaner. Thus a cleaner having excellent water-oil separability in the cleaned waste liquid is desired.
As the above cleaners, there is disclosed a cleaner composition containing (A) a polyoxyalkylene additive of alkyl amine or alkyl amide, having hydrocarbon group with the number of carbon atoms from 8 to 22, and (B) at least one compound selected from the group consisting of an alkyldimethylamine oxide having hydrocarbon group with the number of carbon atoms from 8 to 22, an alkyl-di (aminomethyl)glycine having hydrocarbon with the number of carbon atoms from 6 to 22, a straight chain sodium dodecylbenzene sulfonate, and betaine lauryldimethyl aminoacetate. Furthermore, there is a disclosed cleaner prepared by mixing the (A) component with the (B) component at a specific mixing rate intending to improve the cleanability, the foamability, and the water-oil separability after cleaning, (for example, see Patent document 1.)
In addition, there is a disclosure of water-oil separating cleaner containing an N-alkyl-N-(2-hydroxyalkyl)-iminoethylene carbonate, (for example, see Patent document 2.)    [Patent document] Japanese Patent Laid-Open No. 2003-119496    [Patent document] Japanese Patent No. 3430147
Regarding the cleaning composition disclosed in Patent. document 1, however, a cleaner composition which uses a polyoxyethylene additive of alkylamine or alkylamide having a polyoxyethylene chain with oxyethylene units from 2 to 50, particularly preferably oxyethylene units from 10 to 50, as the (A) component becomes emulsion by itself to show water-soluble property. Thus, when that type of composition is used to the machines, the mechanical parts, and the like to which oils such as grease, engine oil, machine oil, and rust-preventive oil, (in particular grease-base oil, naphthene-base mineral oil, paraffin-base mineral oil, poly-α-olefin, polyol ester, and polydimethyl siloxane), are attached, the satisfactory cleanability and the water-oil separability in the cleaned waste liquid cannot be attained at the same time, and further a problem of rust-generation on the parts to be cleaned arises during or after cleaning.
As for the use of cleaner disclosed in Patent document 2, the water-oil separability after cleaning is significantly influenced by the temperature of the cleaning liquid. Since, at low temperatures, separation of oil layer from aqueous one takes a long time, the reduction in load to the wastewater treatment is not sufficient. In addition, cleanability and rust-preventive performance are not sufficient.


A “universal” prior art motor, such as is shown in FIG. 1, is an electric series wound motor which can run on AC or DC power. Such motors are small, frequently connected directly to standard 110 volt AC power and run at high speed. They are generally employed in hand-held and counter top appliances such as mixers, hand drills, vacuum cleaners and in gardening tools such as edge trimmers and leaf blowers.
Such motors use two field coils wound around two poles for creating a magnetic field in the stator and a rotor with many coils (usually twelve) “wave” wound around the rotor in the rotor slots so that parts of the rotor coil conductor turns lie parallel to the rotor axis. The rotor coils are connected to the commutator pads (usually twelve). Two brushes, which are connected in series with the stator field coils, contact the commutator. The power is connected to the field coils and the speed of the motor is varied by a simple power supply which varies the voltage. When an electric current flows through the conductors of the rotor coils, which are in the magnetic field, the conductors feel a force which turns the rotor about its axis.
No other design has yet as effectively satisfied the special niche need for high speed, variable speed and low cost in small appliances as has the “universal” motor. Typically the speed required in such devices is above 10,000 rpm. Such high speed electric motors deliver high power in a relatively small lightweight package at a low price. The “universal” motor also meets the requirement for smaller motors in hair blowers. In these devices, the motor usually has permanent magnets replacing the stator field coils.
Regardless of whether a stator has coils or permanent magnets for generating magnetic flux, the coils in the rotor also produce a magnetic field which according to some literature “distorts and opposes” the main stator field. This is termed “rotor reaction” and is considered a detriment to efficient motor action.
In the currently used universal motors, with field coils, the longitudinal length of the conductors in the wound rotor is an important parameter because it is the interaction of the conductors with the stator's magnetic field which produces the torque. This torque is found to be approximately proportional to the longitudinal length of the rotor conductors. Therefore, the “bank” of coils in the wound rotor need only be a single “bank” and be whatever length produces the torque desired. The wound rotor purpose is to provide as many conductors, arranged longitudinally, as can be fitted in the space. If there were some other way to do this other than making coils it may still function. The coils are incidental, not essential.
Currently, available universal motors use brushes which are linearly guided and must be connected to electrical power via flexible pigtails. This requires an arrangement which is costly, fragile and subject to breakage and is difficult to service.
Two other types of electric motor have been built. They are the variable reluctance, and the switched reluctance motors. These motors have advantages of low cost through the elimination of unnecessary copper but have severe disadvantages of torque variation (ripple) and acoustic noise which, so far, is only partly mitigated by expensive tailored electronically controlled drives.


1. Field of the Invention
The invention is in the field of computing systems and more specifically in the field of network security.
2. Description of the Related Art
Several approaches to controlling external access to computing networks have been developed. The goals in developing these approaches include limiting access to authorized users and assuring that computing devices employed by these users do not include malicious computing code such as viruses, worms, or Trojan horses. The need for access control has grown with users' demands for accessing secure networks over the Internet and from personal devices such as laptop computers and personal digital assistants.
A first level of access control is achieved by requiring authentication of a user. This may be accomplished by requiring the user to enter a username and password or by reading a MAC address or other identifying information from an access device. In some systems, a network switch is programmed to grant access to a secure network only after proper authentication is achieved. Systems capable of using this approach include those using a proprietary VMPS protocol from Cisco Systems, Inc. of San Jose, Calif. or using a IEEE 802.1x standard protocol.
Reliance on mere user authentication includes several disadvantages. For example, there are no provisions to assure that an access device used by the authenticated user meets network security policies. The access device may have out-of-date virus software, may have security vulnerabilities, or may be otherwise compromised. Further, this approach requires that access points (e.g., network switches) support one of a specific set of access protocols. Because many access points do not support VMPS, 802.1x, or a similar protocol, implementation of this approach on a large preexisting network, such as a corporate network, may be prohibitively expensive.
A greater level of access control may be achieved by including a gatekeeper between the secure network and the access device. The gatekeeper is configured to ensure that the access device conforms to a predetermined security policy. FIG. 1 is a block diagram of a Secure Network, generally designated 100, including two instances of a Gatekeeper 110 each associated with a different instance of an Access Point 120. Secure Network 100 further includes, as an illustrative example, a network File Server 130, a Network PC (personal computer) 140 and a Printer 150 included in and connected via, a local area network designated LAN 125.
Each instance of Access Point 120 may include a large number of individual communication ports. These ports are used to connect through GateKeeper 110 to other elements within Secure Network 100 such as File Server 130 or LAN 125. Large corporate networks may include many instances of Access Point 120, each including hundreds of individual communication ports and being associated with an instance of GateKeeper 110.
Some instances of Access Point 120 are capable of supporting virtual local area networks (VLANs). VLANs are generated by associating communication ports within Access Point 120 with separate virtual networks. For example, one Access Device 160 may be placed on a different VLAN than another Access Device 160 by assigning the communication ports of Access Point 120 to separate VLANs. From the point of view of these devices, the effect of a VLAN is equivalent to having a separate hardwired network.
GateKeeper 110 is configured to control access to Secure Network 100. In addition to authenticating users who wish to access Secure Network 100 using an Access Device 160, GateKeeper 110 is configured to ensure that Access Device 160 conforms to a predetermined security policy, before granting access to Secure Network 100. For example, GateKeeper 110 may make certain that Access Device 160 has up-to-date virus software and encryption protocols as proscribed by the security policy. Once GateKeeper 110 has verified that Access Device 160 satisfies the security policy, Access Device 160 is allowed to communicate through GateKeeper 110 to LAN 125.
A disadvantage of the use of GateKeeper 110, as practiced in the prior art, is that all communications between Access Device 160 and LAN 125 pass through GateKeeper 110. For large networks including many instances of Access Point 120, each of which may include many communication ports, this can be a significant burden. The use of one instance of GateKeeper 110 to support numerous instances of Access Device 160 is limited by bandwidth and required sophistication (e.g., cost) of GateKeeper 110. It is undesirable for GateKeeper 110 to become a limiting factor on the bandwidth of communication between instances of Access Device 160 and Secure Network 100. Further, the use of a separate GateKeeper 110 for each instance of Access Device 160 or Access Point 120 is often prohibitively expensive. Even if a separate GateKeeper is used for each Access Point 120, there is no isolation between compliant and non-compliant Access Devices 160 which are attached to the same Access Point 120.
There is, therefore, a need for improved systems and methods of controlling access to secure networks.


1. Field of the Invention
The present invention relates to a chemically amplified resist composition, and more particularly, to a photosensitive polymer having a cyclic backbone, and a resist composition for an ArF excimer laser obtained therefrom.
2. Description of the Related Art
As semiconductor devices become highly integrated and complicated to fabricate, fine pattern formation is required.
Further, as the capacity of a semiconductor device increases to exceed 1 giga bit, a pattern size having a design rule of less than 0.2, .mu.m is required. Accordingly, there are limitations in using a conventional resist material with a KrF excimer laser (248 nm). Thus, a new resist material capable of being developed using an ArF excimer laser (193 nm) has been developed in a lithography process.
The resist material used in the lithography process using the ArF excimer laser has several problems in being commercially used, compared to the conventional resist materials. The most typical problems are transmittance of a polymer and resistance to dry etching. As the widely known ArF resist materials, (meth)acrylate polymers are generally used. In particular, the most typical resist material is a poly(methyl methacrylate-tert-butyl methacrylate-methacrylic acid) terpolymer system manufactured by IBM, Inc. However, such polymers have very weak resistance to dry etching.
Accordingly, to increase the resistance to dry etching, a polymer having a backbone composed of an alicyclic compound such as an isobornyl group, an adamantyl group or a tricyclodecanyl group, is used. However, the resulting resist still exhibits weak resistance to dry etching.


Windows that can transmit a controllable fraction of incident light intensity would be beneficial in a variety of applications. Thus, windows of buildings or vehicles, windows between rooms, and personal items such as glasses or goggles are often used in situations in which it would be advantageous if their optical transparency could be adjusted, for example by electrical means.
Great efforts have been expended to improve the ways and means of selectively controlling the transmission of light through window structures. A common approach to light control involves using an opaque window shade to reduce the transmission of electromagnetic radiation. Such shades may either be purely mechanical (the most common type) or may be controlled by a motor. Another approach to variable control of light transmission can be achieved by mechanically rotating a pair of polarizing films where the relative angle between polarizing axes of the polarizing films are changed.
Another approach to light control involves the use of polymer films or doping glass with metal ions to absorb or reject certain wavelength range of the electromagnetic radiation. Light transmission through windows using such technologies is fixed once the window structures are constructed.
In recent times, there has been great interest in using variable light transmission glass or glazing to achieve electromagnetic radiation control. A summary of variable tinting window developments can be found in, for example, “Chromogenic Switchable Glazing, Towards Development of the Smart Window” by Carl Lempert, published in the June 1995 Proceedings of the Window Innovation Conference, Toronto, Canada; and “Optical Switching Technology for Glazings” by Carl Lempert, published in Thin Solid Films, Volume 236, 1993, pages 6-13.
Several different types of chromogenic switchable glazing structures have been discovered using suspended particle devices, electrochromic effects, and certain types of liquid crystal. In general, the structures absorb the incident light or diffuse the incident light.
A glazing structure disclosed in U.S. Pat. No. 5,940,150 proposes an adjustable trans-reflective window that is primarily based on two layers of cholesteric liquid crystals and their ability to reject or to transmit one circular polarized light depending on the electric stimulus applied while capable of transmitting the other. However, a specific cholesteric liquid crystal typically works in only a narrow bandwidth of light and a stack of liquid crystal materials are needed to broaden the working wavelength range of the device. Thus, significant material as well as device development effort is needed in order that the glazing structure be practical. The patent also teaches a glazing structure sandwiching a controllable retardation film between two linear reflective polarizers. Such a glazing structure will reflect theoretically 50% to 100%, and transmit 50% to 0%, of naturally polarized light depending on the external stimulus applied. The theoretical contrast ratio between the maximum reflection state and the minimum reflection state of the glazing structure employing linear reflective polarizers disclosed in that patent is therefore only 2:1, making it less desirable as an electrically controllable mirror.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those skilled in the art upon a reading of the specification and a study of the drawings.


This invention relates to computer graphics and, more specifically to a parametric geometric element definition and generation system.
Many applications such as on-line advertisements or promotional graphics require rich image data. As well, better computer graphics capabilities are required by interactive Internet based 3D programming and gaming as well as by real time Internet based simulations. These advanced capabilities are required by advertising agencies, people who create content for the Internet, game developers and entertainment companies. Existing systems are limited because of the large file size associated with graphic, images or image manipulation, the long time required to download content, the lack of rich animatable geometries, the long amount of time required to download level of detail (LOD) data, and the extensive memory and processing time required to generate adaptive level of detail information.
In a computer graphics system, graphic images may be created and/or manipulated by the computer. A graphic image may be displayed on a video display or output to a printer, for example. A graphic image is comprised of a plurality of geometric shapes, or polygons, and textures. As the level of detail increases, the number of polygons and/or textures in the graphic image and, consequently, the size of the image increases. The size of the graphic image affects the time that it takes for the image""s display to be updated on the screen as well as the length of time it takes to send the image from one computer to another. It is desirable to be able to minimize the time needed to transmit an image and/or update its display.
A display screen is comprised of a number of horizontal lines (referred to as scan lines) each of which is comprised of a number of dots (or pixels). To update an image on the screen, the area of the screen that contains the image is redisplayed by refreshing each pixel. This is typically performed by starting at the top left corner of the display and ending with the bottom right corner of the display. A complete scan of the display area is referred to as a frame. The number of frames that are displayed per second is referred to as the frame rate. The higher frame rate is typically desirable.
The frame rate is especially important where the graphic image is changed slightly and redisplayed to give the appearance of movement or animation. A low frame rate causes the animation to appear jerky. By lowering the level of detail (e.g., the number of polygons that must be drawn), the frame rate may be increased. However, a lower level of detail may cause the image to appear blocky and unrealistic.
Using existing approaches, each version of the image and/or different levels of detail of each version are created as different images (i.e., different xe2x80x9csnapshotsxe2x80x9d of the image). Before these images may be transmitted to another computer, a data representation of the images must be generated.
One mechanism for generating a data representation of an image is the Virtual Reality Modeling Language (VRML). VRML is a text-based definitional language comprising a statement syntax used to define a graphic image. A VRML file is created to define an image containing VRML statements that define nodes (e.g., sphere, cylinder, cone, cube, translation and transform) and fields (e.g., radius, height, width, and depth) that distinguish one node from another. The following is an example of VRML statements that define a red sphere:
Transform {
translation 301
children [
Shape {
geometry Sphere {radius 2.3}
appearance Appearance {material Material {
diffuseColor 100 #Red
}}
}
]
}
The VRML statements identify five nodes (i.e., xe2x80x9cTransformxe2x80x9d, xe2x80x9cShapexe2x80x9d, xe2x80x9cSpherexe2x80x9d, xe2x80x9cAppearancexe2x80x9d and xe2x80x9cMaterialxe2x80x9d) and fields associated with the nodes. The xe2x80x9cSpherexe2x80x9d node identifies a geometric shape (i.e., sphere) and the xe2x80x9cradiusxe2x80x9d field indicates that the sphere is to have a radius of 2.3. The xe2x80x9cAppearancexe2x80x9d and xe2x80x9cMaterialxe2x80x9d nodes affect the way the sphere is drawn. The material node with a xe2x80x9c1 0 0xe2x80x9d value for its xe2x80x9cdiffuseColorxe2x80x9d field indicates that the sphere is red. The xe2x80x9cShapexe2x80x9d node associates the xe2x80x9cAppearancexe2x80x9d node with the xe2x80x9cSpherexe2x80x9d node. The xe2x80x9cTranslationxe2x80x9d node defines a movement of the sphere to a new location as indicated by the xe2x80x9ctranslationxe2x80x9d field and its value of xe2x80x9c3 0 1xe2x80x9d. A VRML representation is read and the node and field information is used to generate an image.
A VRML representation of an image represents a static state, or snapshot, of the image. Changes to the level of detail within the image, for example, are done by generating a new VRML representation of the image. Where the sphere is to be displayed on another computer, each of these representations must be sent to the computer before they can be used to display the sphere on the other computer.
The VRML representations of the sphere may be sent via the Internet, for example. Most users connect to the Internet using a modem with a maximum transmission rate that is frequently not achieved due to the quality of the phone line(s) used to transmit the data. The transmission rates using a modem connection are not sufficient to provide continuous streams of image data for processing by a computer. It would be beneficial to be able to the processing capabilities available with existing computer systems and minimize the amount of image data that must be transmitted between computer systems.
U.S. Pat. No. 5,581,672 Dec. 3, 1996 Letcher, Jr. and U.S. Pat. No. 5,856,828, Jan. 5, 1999 Letchter, Jr. describe a system of relational entities for object-oriented computer-aided geometric design. In the patents, geometric objects are defined and constructed in a system which retains and utilizes relationsip and dependencies between objects in a directed graph data structure.
A parametric geometric element definition and generation system and method is described herein. Embodiments of the invention comprise a model having a plurality of modeling operations and parameters or properties used in defining and generating geometric elements. In one or more embodiments of the invention, the model is a directed acyclic graph of three-dimensional modeling operations that combine to store information about a process used to construct an image. In one or more embodiments of the invention an object player monitors a model, communicates initialization and modifications of geometric data to the rendering system, and provides geometric data to the rendering system in the appropriate data formats.
In one or more embodiments of the invention, the model and modeling operations are object-oriented objects having properties and methods. One embodiment of the invention comprises geometry, core, operation and player object classes.
Geometry object classes comprise the geometric data (e.g. coordinate, color, normal and texture coordinate data). The geometry object allows data to be shared by describing faces as lists of indices into the data pools. Core classes provide the fundamental communication and generation mechanism used by the model and comprise exceptions, change events, and operation superclasses. The operation classes comprise classes that may generate a geometric object or combine geometric objects to create new geometric objects. The object player provides an interface between the model and the underlying rendering system and may initiate a generation request. Geometric object data is returned to the object player in response to a generation request. This geometric object data is then forwarded to the underlying rendering system for rendering the image.
A notification mechanism is used where objects may send and/or listen for change events. A modification to one or more properties of the model and/or modeling operations may trigger the transmission of a change event. The change event indicates to interested parties (e.g., other modeling operations, the model and for the object player) that an update to their geometric output, or other action, may be needed. A tracking mechanism provides the ability to determine what properties have been changed and assists in determining a response to a generate request. Each modeling operation has the ability to respond to a generate request. In an embodiment of the invention, the generation process is a depth-first traversal of the model graph structure. Generation may be limited to those operations of the model whose properties have been modified, and those operations that depend on the modified operation whose properties have been modified.
Different xe2x80x9csnapshotsxe2x80x9d of an image may be generated at runtime by modifying one or more parameters of operations within a model of the image and then asking the graph to generate. Each snapshot may provide a different level of detail or animation, for example. In one embodiment of the invention, a predictive mechanism is used to determine an optimal level of detail.
In one or more embodiments of the invention, a prediction scheme is used to determine the effect on rendering time of image changes. Rendering times are collected and any differences in rendering times between rendering passes are allocated to the changed geometric objects. It is therefore possible to collect statistics on the effect on rendering time of making various changes to the image. It is possible, for example, to predict the rendering times for different levels of detail associated with a geometric object. Predictions may be used in selecting the appropriate level of detail to achieve a desired frame rate.
In accordance with a further aspect, the invention is directed to a method of computer aided 3D modelling of geometric objects undergoing changes wherein a directed acyclic graph is executed to generate a 3D model, the directed acyclic graph including a plurality of nodes which are connected with other nodes with directed edges between two nodes, each node representing a modelling operation of the geometric objects and each directed edge indicating the direction of flow of data from one node to another. The method comprises steps of a first node sending a change event indication specifying changes to bound properties of the node to a series of nodes in succession along associated directed edges and each node in succession determining if the change event indication received from a preceding node affects its bound properties and further determining based on its own rules that its own change event indication should be sent to a succeeding node. The method includes further steps of sending the change event indication to the succeeding node, and last node in succession instructing a rendering system to render a 3D model in accordance with the received change event indication.
In accordance with a yet another aspect, the invention is directed to a method of computer aided 3D modelling of geometric objects undergoing changes wherein a directed acyclic graph is executed to instruct a rendering system to generate a 3D model, the directed acyclic graph including a plurality of nodes which are connected with other nodes with directed edges between two nodes, each node representing a modelling operation of the geometric objects and each directed edge indicating the direction of flow of data from one node to another. The method comprises steps of (a) executing continually the directed acyclic graph to instruct the rendering system to generate a series of frames of a 3D model of geometric objects which are undergoing changes and (b) measuring a time required for the rendering system to generate a predetermined numbers of preceding frames with respect to a target time. The method further includes steps of (c) modifying bound properties of one or more nodes and (d) repeating iteratively steps (b) and (c) so that the time required for the rendering system to generate the most recent frame approach the target time.
According to another aspect, the invention is directed to a computer aided 3D modelling apparatus for modelling 3D models of geometric objects undergoing change which comprises an instruction storage module containing a directed acyclic graph to be executed to generate a 3D model, the directed acyclic graph including a plurality of nodes which are connected with other nodes with directed edges between two nodes, each node representing a modelling operation of the geometric objects and each directed edge indicating the direction of flow of data from one node to another. The apparatus further includes an input port for inputting changes in bound properties, defined below, of one or more nodes, an instruction execution module for executing the directed acyclic graph to generate an output, an object player module for monitoring the output and regenerating the directed acyclic graph in response to the output if needed, and the rendering system for rendering the 3D model of geometric objects in response to the instructions.


Content displayed on a web page can be generated by one or more content item servers in response to content item requests that are generated during the rendering of the web page by a client device. Often a publisher of a web page may define multiple content item environments, e.g., advertisement slots, for content items, e.g., advertisements, to be displayed within a web page. Typically, each content item environment has an associated content item request e.g. an advertisement request, that is transmitted to a content item server, e.g., an advertisement server. When the web page is rendered by a client device that has requested the publishier's web page, a content item will be displayed in each content item environment.
A web page having multiple content item environments can, however, generate excessive traffic to the content item server. Additionally, because web page instructions are often interpreted, the content item requests are generated as each content item request instruction is processed. Accordingly, a first content item request for a web page is transmitted and served without knowledge of any subsequent content item requests that may be encountered for that page. Thus, each content item served by the content item server for a web page if the rendering of the web page generates multiple content item requests.


Field of the Invention
The present invention relates to an imaging lens which forms an image of an object on a solid-state image sensor such as a CCD sensor or a C-MOS sensor used in a compact image pickup device, and more particularly to an imaging lens built in an image pickup device mounted in an increasingly compact and low-profile smartphone or mobile phone, PDA (Personal Digital Assistant), game console or information terminal such as a PC, or a home appliance with a camera function.
Description of the Related Art
In recent years, there has been a general tendency that mobile terminals such as smartphones and home appliances have a camera function. Today, whereas high-end models with a high-resolution camera function comparable to a digital still camera have been introduced into the market, the need for inexpensive popular models with a certain level of camera performance is still high. An imaging lens composed of three elements (constituent lenses) may be suitable as an imaging lens to be built in an inexpensive popular model because it can deliver a certain level of imaging performance and can be applied to a low-profile device and supplied at low cost. However, with the recent trend toward smaller higher-pixel image sensors, the pixel size is becoming smaller and the pixel density is becoming higher. Nowadays, image sensors with a pixel pitch of less than 1.2 microns have been proposed. An imaging lens for use in such an image sensor is expected to not only feature the smallness of aberrations but also provide a high-brightness optical system with an F-value smaller than 2.8 (often seen in the past). As for mobile terminals in particular, the imaging lens is expected to be low-profile enough to be applicable to a low-profile product. Furthermore, the imaging lens is anticipated to be able to capture an image of an object over a wide field of view so as to flexibly cope with the various camera functions of the product.
Conventionally, as an example of an imaging lens composed of three constituent lenses, the imaging lens described in JP-A-2010-113306 (Patent Document 1) includes, in order from an object side, an aperture stop, a first lens with positive refractive power, a second lens with negative refractive power, and a third lens. The third lens has, on the both sides, aspheric surfaces which are convex-curved toward the object near an optical axis and concave-curved toward the object in the vicinity of the lens periphery so that the refractive power changes according to the distance from the optical axis. The thickness of the first lens on the optical axis, the air gap on the optical axis between the first and second lenses, the focal length of the third lens, and the relation in curvature radius between the object-side surface and the image-side surface of the first lens are determined so as to achieve a wide field of view.
The imaging lens described in JP-A-2007-127953 (Patent Document 2) is an optical system which corrects chromatic aberrations using a diffractive optical surface. The imaging lens described in Patent Document 2 includes at least three constituent lenses and at least one of the lens surfaces of these lenses has a diffractive surface. At least one of the lens surfaces of the lens located nearest to the image plane has negative optical power in its center and the optical power changes to positive power as the distance to the lens periphery decreases, making up a compact optical system with high telecentricity.
According to Patent Document 1, the imaging lens can capture an image of an object over a wide field of view from 76 to 78 degrees and corrects aberrations relatively properly. However, since the F-value is 2.8, there is difficulty in applying the imaging lens to a compact high-density image sensor as mentioned above. The imaging lens described in Patent Document 1 has a total track length of 4.6 to 5.5 mm and the ratio of the total track length to the diagonal length of the effective imaging plane of the image sensor (divide total track length by diagonal length of the effective imaging plane of the image sensor; hereinafter referred to as the ratio to diagonal) is about 1.0; however, in order to make the imaging lens more low-profile and offer brightness with an F-value of 2.8 or less, the problem related to correction of aberrations has to be addressed.
According to Patent Document 2, the imaging lens can capture an image of an object over a maximum field of view of 72 degrees and corrects aberrations relatively properly. However, the positive, positive and negative refractive power lenses are arranged in order from the object side and chromatic aberrations are corrected not by the combination of the first and second lenses but by the diffractive optical surface. When the dependence on the diffractive optical surface for correction of chromatic aberrations is high, the number of orbicular zones formed on the lens surface tends to increase, which means that flare is more likely to occur. If two diffractive optical surfaces are formed to address this problem, high precision is required in the lens forming and assembling processes to prevent misalignment between the diffractive optical surfaces, which implies a higher degree of manufacturing difficulty. In connection with low-profileness, the third lens, located nearest to the image plane, has negative refractive power and the back focus is relatively long, making it difficult to achieve low-profileness. In the imaging lens composed of three constituent lenses as described in Patent Document 2, the total track length is about 6.8 mm and the ratio to diagonal is more than 1.1. If the back focus is decreased to achieve low-profileness, the angle of incidence on the third lens must be increased and as a consequence, probably the effective diameter of the second lens must be larger. When the lens diameter is larger, spherical aberrations and coma aberrations increase. This will make it difficult to make the imaging lens more low-profile while ensuring high performance. In addition, since the F-value of the imaging lens disclosed in Patent Document 2 is 3.3, it is difficult to apply the imaging lens to the latest high-density image sensors.


Currently, with the development of computer technology and electronic technology, electronic devices such as smart mobile phones, mobile Internet devices (MIDs), personal digital assistants (PDAs), and tablet computers have become indispensable tools for communication and entertainment in people's daily work and life. Users often use electronic devices for daily reading. When finding a content of interest during reading, users often want to make duplicates for sharing the content of interest. However, when the duplicated content includes both text information and pictures, the pictures in the duplicated content are often filtered out, causing the duplicated content inconsistent with the originally displayed content and affecting the user experience.


The present invention relates to an optical multi-wavelength selective device, more precisely a multi-wavelength selective switch for rerouting and switching of wavelengths in an optical network, in which each wavelength may be separately rerouted. The invention also comprises a method for rerouting and switching or add/drop multiplexing of wavelengths in an optical network.
In order to further increase the capacity on existing optical networks a number of methods are known. One means is to use so called wavelength division multiplexing (WDM) technique in order to improve the degree of utilization of the available bandwidth. In order to increase the network flexibility, devices able to reroute traffic in the optical network are necessary. Such devices for rerouting of the traffic are also suitable in order to utilize the network as efficiently as possible, and in case of network interrupts.
In xe2x80x9cWavelength Division Multiplexer with Photoinduced Bragg Gratings Fabricated in a Planar Lightwave Circuit Type Asymmetric Mach Zehnder Interferometer on Sixe2x80x9d Y. Hibino et.al., IEEE Photonics Technology Letters, Vol. 8, No. 1, January 1996 an optical element is described in which Bragg grating and a phase control element is used in a Mach Zehnder interferometer. The considered applications are wavelength division multiplexing and wavelength division de-multiplexing.
The above described device can however not be used as a multi-wavelength selective switch. If the described device is to be used for add/drop of several channels, as many devices are needed as the number of handled add/drop pairs. This type of device is comparatively hard to reconfigure, i.e. it is a non-adaptable device.
In K. W. Cheung, D. A. Smith, J. K. Baran, J. J. Johnson: xe2x80x9cWavelength-selective circuit and packet switching using acousto-optic tunable filtersxe2x80x9d Globecom ""90, pp 1541-1547, 1990, a manner is described of solving multi-wavelength selective rerouting of wavelength channels separate and independently of each other based on opto-aucoustic switches. This type of rerouting typically uses a number of micro-seconds, which may be a problem in high speed transmissions.
In R. C. Alferness, L. L. Buhl, U. Koren, B. I. Miller, M. Young, T. L. Koch.xe2x80x9d Broadly tunable InGaAsP/InP buried rib waveguide vertical coupler filterxe2x80x9d, Techn. Dig. Integrated Photonics Research, post-deadline paper, pp. 33-36, 1991 a tunable wavelength selective grating-assisted directional coupler comprising two waveguides having different effective refractive indexes and a grating described. This directional coupler can couple a wavelength from the first waveguide to the second waveguide.
The problem present in the known technique as regards multi-wavelength selective switches and re-directional devices is this demand very big and complicated structures or more components, which results in big power losses and high costs, or in that they can not be used in connection with high speed transmissions.
In order to increase the capacity in an optical transmission system several know methods may be used. In wavelength division multiplexing the transmission channels are multiplexed and de-multiplexed on different carrier wavelengths to respectively from an information flow. Said multiplexing and de-multiplexing demands optical multi-wavelength selective devices. It may also be desirable to change the transmission route through the optical net for certain wavelength channels. For this purpose components are needed having multi-wavelength selective performance characteristics such as a multi-wavelength selective switch.
A known problem related to multi-wavelength selective switches may be that these contribute to big power losses.
Another problem is that all by us known multi-wavelength selective switches known to us exhibited a relatively complicated structure or a great number of components.
Another problem is that known multi-wavelength selective switches are relatively expensive to manufacture depending on said complicated structures or the number of components comprised.
Yet a problem is that certain known multi-wavelength selective switches exhibit relatively slow switching speeds, typically a number of microseconds.
The present invention approaches the said problem through a multi-wavelength selective switch in the form of a directional coupler structure comprising two waveguides arranged having different effective refractive index. The waveguides are at one section arranged in the proximity of each other, such that an optical field in each of the waveguides may overlap the other wherein at least one grating is arranged for co-directional coupling.
In a method according to the invention for switching and re-direction of optical wavelengths in an optical network one branch in a directional coupler structure comprising optical wavelengths is excited. The optical wavelengths are thereafter transmitted through said branch to the directional coupler structure. The optical wavelengths are thereafter transmitted through a section where the waveguides are arranged in the proximity of each other whereby none or at least one wavelength is influenced by at least one in this section arranged grating for co-directional coupling and is coupled to the other waveguide.
In a second embodiment according to the invention at least one wavelength selective amplifier is comprised in at least one branch of the directional coupler structure, e.g. in the form of a distributed-Bragg-reflector-amplifier.
The object of the present invention is to obtain a multi-wavelength selective switch, the structure of which is so simple and compact as possible, such that the manufacturing thereby may be reduced compared to the available technique, and in which the switching speed still is relatively high.
An advantage of the present invention is that the power losses relatively seen may be kept low.
A further advantage of the present invention is that its remaining performance characteristics such as crosstalk and the like may be improved compared to know technique.
Still a further advantage of the present invention is that signal splitting only is performed when absolutely necessary.
The invention will now be described further using the preferred embodiments and with reference to the appended drawings.


This invention relates to subsea wellhead systems and more particularly, to methods and apparatus for supporting, holding down, and sealing casing hangers within a subsea wellhead.
Increased activity in offshore drilling and completion has caused an increase in working pressures such that it is anticipated that new wells will have a working pressure of as high as 15,000 psi. To cope with the unique problems associated with underwater drilling and completion at such increased working pressures, new subsea wellhead systems are required. Wells having a working pressure of up to 15,000 psi are presently being drilled off the coast of Canada and in the North Sea in depths of over 300 feet. These drilling operations generally include a floating vessel having a heave compensator for a riser and drill pipe extending to the blowout preventer and wellhead located at the mud line. The blowout preventer stack is generally mounted on 20 inch pipe with the riser extending to the surface. A quick disconnect is often located on top of the blowout preventer stack. An articulation joint is used to allow for vessel movement. Two major problems arise in 15,000 psi working pressure subsea wellhead systems operating in this environment, namely, a support shoulder in the wellhead housing which will support the casing and pressure load, and a sealing means between the casing hangers and wellhead which will withstand and contain the working pressure.
In the past, prior art wellhead designs permitted adequate landing support for successive casing hangers. However, with the increase in pressure rating and the landing and supporting of multiple casing strings and tubing strings within the wellhead, a small support shoulder will not support the load. Although an obvious answer to the problem would be to merely use a support shoulder large enough to support the casing and pressure load, large support shoulders projecting into the flow bore in the wellhead housing restrict access to the casing below the wellhead housing for drilling. In the early days of offshore drilling, 16-3/4 inch bore subsea wellhead systems required underreaming. At that time, most floating drilling rigs were outfitted with a 16-3/4 inch blowout preventer system to eliminate the two stack (20 inch and 13-5/8 inch) and the two riser system required up until that time. As wellhead systems moved from 5,000 psi to 10,000 psi working pressure, the 18-3/4 inch, 10,000 psi support shoulder was developed to carry casing and pressure loads and to provide full access into the casing below the wellhead housing.
The second major problem is the sealing means. The sealing means must be capable of withstanding and containing 15,000 psi working pressures. Available energy sources for energizing the sealing means include weight, hydraulic pressure, and torque. Each sealing means requires different amounts of energy to position and energize. Weight is the least desirable because the handling of drill collars providing the weight is difficult and time consuming on the rig floor. If hydraulic pressure is applied through the drill pipe, there is a need for wireline equipment to run and recover darts from the hydraulic-to-actuated seal energization system. If darts are not used, the handling of "wet string" of drill pipe is very messy and unpopular with drilling crews. If the seal energization means uses the single trip casing hanger technique, the cementing fluid can cause problems in the hydraulic system used to energize the seal. Maintenance is also a problem. Although torque is the most desirable method to energize a seal, there are limitations on the amount of torque which can be transmitted from the surface due to friction losses to riser pipe, the blowout preventer stack, off location, various threads, and the drill pipe itself.
The subsea wellhead system of the present invention overcomes the deficiencies of the prior art and includes many other advantageous features. The system is simple, has less than 50 parts and is suitable for H.sub.2 S service. The system has single trip capability but can still use multiple trip methods. All hangers are interchangeable with respect to the outer profile so that they can be run in lower positions. The seal elements are interchangeable and are fully energized to a pressure in excess of the anticipated wellbore pressure. Back-up seals are available. The seals are not pressure de-energized. The hangers can be run without lock downs and the seal elements will seal even if the hanger lands high.
The housing support seat supports in excess of 6,000,000 lbs. (working pressure plus casing weight or test pressure) without exceeding 150% of material yield in compression. The wellhead will pass a 17-1/2 inch diameter bit. The present invention does not attempt to land on two types of seats at once or on two seats at once. Further, the housing support seat is not sensitive to collecting trash during drilling or to collecting trash during the running of a 13-3/8 inch casing. Further, the housing support seat does not require a separate trip nor does it drag snap rings down the bore.
The hanger hold down will hold down 2,000,000 lbs. The hanger hold down is positively mechanically retracted when retrieving the casing hanger body and is compatible with single trip operations. The hanger hold down is released for retrieval of the casing hanger when the seal element is retrieved. The hanger hold down is compatible with multiple trip operations and permits the running of the hanger with or without the hold down. The sealing means will work even if the hold down is not used. The hanger hold down is reusable and has a minimum number of tolerances to stack up between hold down grooves.
The sealing means of the present invention will reliably seal an annular area of approximately 18-1/2 inch outside diameter by 17 inch inside diameter and provide a rubber pressure in excess of 15,000 psi (20,000 psi nominally) when the sealing means is energized and the sealing means sees a pressure from above or below of 15,000 psi. The pressure in excess of 15,000 psi is retained in the sealing means after the running tool is removed. The sealing means is additionally self-energized to hold full pressure where full loading force was not applied or where full loading force was not retained. The sealing means will not be pressure de-energized. The sealing means provides a relatively long seal area to bridge housing defects and/or trash. Further, the sealing means provides primary metal-to-metal seals and used the metal-to-metal seals as backups to prevent high pressure extrusion of secondary elastomeric seals. The sealing means of the present invention positively retracts the metal-to-metal seals from the walls prior to retrieving the sealing means. The elastomeric seals of the sealing means are allowed to relax during retrieval of the packoff assembly and is completely retrievable. The present sealing means provides a substantial metallic link between the top and the bottom of the packing seal area to insure that the lower ring is retrievable. The design allows for single trip operations. There are no intermittent metal parts in the seal area to give irregular rubber pressures. The sealing means provides a minimum number of seal areas in parallel to minimize leak paths. The sealing means is positively attached to the packing element so that it cannot be washed off by flow during the running operations. The design also allows for multiple trip operations and is interchangeable for all casing hangers within a nominal size.
The means to load the sealing means reliably provides a force to energize the sealing means to a nominal 20,000 psi. It allows full circulation if used in a single trip. However, the loading means is compatible with either a single trip operation or multiple trip operation. Further, it is interchangeable for all casing hangers within the wellhead system. The loading means will cause the sealing means to seal even if the casing hanger is set high. Further, it does not release any significant amount of the full pressure load after actuation. The loading means does not require a remote engagement of hold down threads. Further, it has no shear pins. The loading means is reusable and does not have to remotely engage hold down threads on packing nut replacement.
The casing hanger running tool includes a connection between the running tool and casing hanger which will support in excess of 700,000 lbs. of pipe load. The running tool is able to generate an axial force in excess of 900,000 lbs. to energize the sealing means. Further, the running tool is able to tie back into the casing hanger without a left hand torque. The running tool can be run on either casing or drill pipe.
Other objects and advantages of the invention will appear from the following description.


Chromatography and solid-phase extraction (“SPE”) are commonly-used separation techniques employed in a variety of analytical chemistry and biochemistry environments. Chromatography and SPE are often used for separation, extraction, and analysis of various constituents, or fractions, of a sample of interest. Chromatography and SPE may also be used for the preparation, purification, concentration, and clean-up of samples.
Chromatography and SPE relate to any of a variety of techniques used to separate complex mixtures based on differential affinities of components of a sample carried by a mobile phase with which the sample flows, and a stationary phase through which the sample passes. Typically, chromatography and SPE involve the use of a stationary phase that includes an adsorbent packed into a cartridge, column, or disposed as a thin layer on a plate. Thin-layer chromatography (“TLC”) employs a stationary phase that is spread in a thin layer on a carrier or substrate plate. A commonly-used stationary phase includes a silica-gel-based sorbent material.
Mobile phases are often solvent-based liquids, although gas chromatography typically employs a gaseous mobile phase. Liquid mobile phases may vary significantly in their compositions depending on various characteristics of the sample being analyzed and on the various components sought to be extracted and/or analyzed in the sample. For example, liquid mobile phases may vary significantly in pH and solvent properties. Additionally, liquid mobile phases may vary in their compositions depending on the characteristics of the stationary phase that is being employed. Often, several different mobile phases are employed during a given chromatography or SPE procedure. For example, gradient elution may be performed in which the mobile phase composition is varied with time.
A typical TLC plate is prepared by mixing an adsorbent (which acts as the stationary phase) with a small amount of an inert binder and water. The mixture may be spread as a relatively viscous slurry onto a carrier sheet. The resulting plate can then be dried and activated in an oven. The resulting stationary phase is bound in place to the carrier sheet or other substrate by the binder. The presence of the binder can lead to secondary interactions with the mobile phase, as well as a decrease in separation efficiency.


A. Technical Field
The present invention relates to a process for producing a hydroxyalkyl (meth)acrylate by performing a reaction between (meth)acrylic acid and an alkylene oxide.
B. Background Art
In the case of producing a hydroxyalkyl (meth)acrylate by performing a reaction between (meth)acrylic acid and an alkylene oxide, the formation of a diester (alkyleneglycol di(meth)acrylate) as a by-product has so far been a problem. The diester has two unsaturated bonds within one molecule, and promotes the polymerization of an object, the hydroxyalkyl (meth)acrylate, and causes the trouble such as clogging of an apparatus. Furthermore, in the case of producing a (co)polymer from a raw material of the hydroxyalkyl (meth)acrylate containing the diester, turbidity arises in the resulting polymer, or the hydroxyalkyl (meth)acrylate containing the diester causes the occurrence of gelation at the time of polymerization. Furthermore, the vapor pressure of the diester is approximate to that of the hydroxyalkyl (meth)acrylate. Therefore, once the diester is formed, the separation thereof is extremely difficult. In addition, when an object, the hydroxyalkyl (meth)acrylate is distilled and purified, the diester is also formed by a disproportionation reaction thereof.
It is known that the diester is apt to form when a reaction liquid of (meth)acrylic acid and the alkylene oxide, or the resulting hydroxyalkyl (meth)acrylate is elevated to a high temperature (e.g. JP-A-133227/1976). Therefore, if a reaction temperature or a distillation temperature is low, the formation of the diester is controlled to some degree. However, when the reaction temperature is low, the period of reaction step time lengthens very much, and so that there is not only a possibility that the productivity falls, but also a possibility that part of a product polymerizes because of the long period of reaction step time or that other by-products increase. Accordingly, falling the reaction temperature or the distillation temperature is not a practical countermeasure.
A method of controlling the formation of the diester at the time of distillation by deactivating a specific catalyst used in the reaction is disclosed (e.g. JP-A-194321/1993). However, there is a disadvantage that the available catalyst is limited, or that the catalyst is not applicable to the formation of the diester at the time of the reaction, and the control effect thereof was insufficient.
A. Object of the Invention
An object of the present invention is to provide a process for producing a hydroxyalkyl (meth)acrylate which enables to control the formation of a diester sufficiently at the time of reaction and/or at the time of distillation.
B. Disclosure of the Invention
The present inventors diligently studied to achieve the above object. As a result, they have found that the above object could be solved completely by allowing a liquid with a specific relative dielectric constant to coexist at the time of a reaction between (meth)acrylic acid and an alkylene oxide and/or at the time of distillation of a hydroxyalkyl (meth)acrylate.
That is to say, a process for producing a hydroxyalkyl (meth)acrylate, which comprises the step of carrying out a reaction between (meth)acrylic acid and an alkylene oxide in the existence of a catalyst; with the process being characterized in that when the reaction between (meth)acrylic acid and the alkylene oxide is carried out, there coexists a liquid having a relative dielectric constant of not less than 20 at 25xc2x0 C.
An another process for producing a hydroxyalkyl (meth)acrylate, which comprises the step of carrying out a reaction between (meth)acrylic acid and an alkylene oxide in the existence of a catalyst; with the process being characterized by further comprising the step of distilling the resultant hydroxyalkyl (meth)acrylate in the coexistence of a liquid having a relative dielectric constant of not less than 20 at 25xc2x0 C.
These and other objects and the advantages of the present invention will be more fully apparent from the following detailed disclosure.
First, an outline of a process for producing a hydroxyalkyl (meth)acrylate which the characteristic production process of the present invention can favorably apply to is explained as follows.
First, a reaction between (meth)acrylic acid and an alkylene oxide is carried out in the existence of a catalyst. The reaction rate of this reaction does not reach 100% in many cases, and it is general that the unreacted (meth)acrylic acid or alkylene oxide or such remains in a reaction liquid at the time of the end of the reaction. Then, the above reaction liquid is introduced into the step of removing the unreacted raw materials and such from the reaction liquid. As the subsequent final step, purification such as distillation is performed to obtain an object, the hydroxyalkyl (meth)acrylate.
Hereinafter, the features of the production process of the present invention are explained below.
The alkylene oxide which can be used in the present invention are favorably an alkylene oxide having 2 to 6 carbon atoms, more favorably an alkylene oxide having 2 to 4 carbon atoms. Examples thereof include ethylene oxide, propylene oxide, and butylene oxide, more favorably ethylene oxide and propylene oxide. Incidentally, (meth)acrylic acid used in the present invention means acrylic acid or methacrylic acid.
When the present invention is carried out, the amount of raw materials as charged for the above reaction between the (meth)acrylic acid and the alkylene oxide is favorably in the range of not less than 1 mol of the alkylene oxide per 1 mol of the (meth)acrylic acid, more favorably in the range of 1.0 to 5.0 mol, still more favorably in the range of 1.0 to 3.0 mol, especially favorably in the range of 1.0 to 2.0 mol. In the case where the amount of the alkylene oxide as charged is less than 1.0 mol, it is unfavorable because the reaction rate falls and by-products increase. When the amount of the alkylene oxide as charged is too much, especially more than 5 mol, it is unfavorable economically.
In the present invention, the reaction between the (meth)acrylic acid and the alkylene oxide in the existence of the catalyst can be performed by a method which is conventionally used for this kind of reaction.
In the case where the reaction is performed by a batch method, the reaction is performed by introducing a liquid alkylene oxide into the (meth)acrylic acid. The alkylene oxide may be introduced after the (meth)acrylic acid is dissolved in a solvent. In this case, the alkylene oxide may be added all at once, continuously, or intermittently. In the case of adding the alkylene oxide continuously or intermittently, as is often the case with this kind of reaction, the reaction can be completed by the so-called aging that is carried out by continuing the reaction after introducing the alkylene oxide. Furthermore, it is not always necessary to add the (meth)acrylic acid all at once in the initial stage, and the (meth)acrylic acid can be added after being divided into some portions.
In the case where the reaction is performed by a continuous method, the reaction is performed by adding the (meth)acrylic acid and the liquid alkylene oxide into a reactor such as a tubular or tank reactor continuously and extracting a reaction liquid out of the reactor continuously. In this case, a catalyst may be provided continuously together with raw materials and b e extracted continuously together with the reaction liquid. In the case of using the reactor such as the tubular reactor, a so-called fixed bed manner in which a solid catalyst as packed with the reactor is used may be utilized. In the case of using the reactor such as the tank reactor, the so-called fluidized bed manner in which a solid catalyst as fluidized together with the reaction liquid in the reactor is used may be used. Furthermore, in the cases of these continuous reactions, modes which allow part of the reaction liquid to circulate may be used.
The reaction temperature is usually favorably in the range of 40 to 130xc2x0 C., more favorably 50 to 100xc2x0 C. If the reaction temperature is below 40xc2x0 C., it takes more time for the reaction to proceed and it becomes apart from a practical level. On the other hand, if the reaction temperature is above 130xc2x0 C., it is unfavorable because by-products become large, or the polymerization of the (meth)acrylic acid of a raw material, the hydroxyalkyl (meth)acrylate of the product and such arise.
Furthermore, this reaction may be performed in a solvent for the purpose of allowing the reaction to proceed mildly or such. As to the solvent, conventional ones such as toluene, xylene, heptane and octane are usable. The pressure in a reaction system during the reaction depends on the kinds or mixing ratios of used raw materials. However, the reaction is usually performed under applied pressure.
In the reaction, conventional polymerization inhibitors are usable. Examples thereof include hydroquinone, hydroquinone monomethyl ether, phenothiazine, copper dibutyldithiocarbamate, or such. The amount of the polymerization inhibitor as added is not especially limited, and is favorably in the range of 0.001 to 1 weight % of a carboxylic acid, more favorably in the range of 0.01 to 0.5 weight %.
In the production process of the present invention, a catalyst used in the reaction between the (meth)acrylic acid and the alkylene oxide is not especially limited, and a catalyst which is used conventionally in this kind of reaction can be used. Examples thereof include iron compounds such as ferric chloride and ferric acetate; chromium compounds such as chromium chloride, chromium acetylacetonate, chromium formate, chromium acrylate, chromium methacrylate, chromium dibutyldithiocarbamate, chromium nitrate, chromium sulfate; amines such as trialkylamines and ion-exchange resins having a quaternary ammonium group. It is favorable to use a basic catalyst such as an amine compound or a basic resin. This basic resin is a high-molecular compound with a basic functional group which is insoluble in a reaction liquid. Examples thereof include tertiary amine compounds, quaternary ammonium salts, cyclic amine compounds such as pyridine, high-molecular compounds with sulfides, favorably basic anion-exchange resins, especially favorably basic anion-exchange resins having an amino group as a basic functional group.
Incidentally, the production process of the present invention enables to reveal the effect of controlling the formation of the diester sufficiently without using a chromium compound with valence number of 6 such as chromic anhydride which has so far exhibited the relatively high effect of controlling the formation of the diester as a catalyst.
In the production process of the present invention, distillation of the product of the hydroxyalkyl (meth)acrylate can be performed according to a method which is conventionally used for this kind of distillation, and for example a distillation apparatus having a portion of a vacant column is enumerated. Furthermore, a thin-film evaporation apparatus may be used in combination.
In the case of using the distillation apparatus with the portion of the vacant column, the so-called distillation column is favorable. The structure thereof can be simple distillation and examples thereof include rectifying columns such as a packed column, a bubble cap tower and a perforated-tray column. Especially, a distillation column comprising plural sieve trays or a distillation column comprising packed materials is favorable. Furthermore, a multi-plated perforated-tray column is desirable from a viewpoint of the maintenance of purity or the removal of a polymer. In the method of heating, a method which uses jacket type heaters or a reboiler method which allows bottoms to circulate and performs heating with shell-and-tube heat-exchangers is included. With respect to the pressure condition of distillation, it is favorable to perform distillation under reduced pressure. It is desirable that the operating pressure should be as low as possible from a viewpoint of preventing polymerization, favorably in the range of 0.66 to 40 hPa, more favorably in the range of 1.33 to 13 hPa, still more favorably in the range of 4 to 9.3 hPa. A liquid temperature in the distillation apparatus is usually favorably in the range of 70 to 130xc2x0 C., more favorably in the range of 80 to 110xc2x0 C.
The production process according to the present invention is characterized by carrying out the reaction between the (meth)acrylic acid and the alkylene oxide and/or distillation of the resultant hydroxyalkyl (meth)acrylate as explained in the above in the coexistence of a liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. This enables to exhibit the effect of controlling the formation of the diester sufficiently on the occasion of the reaction between the (meth)acrylic acid and the alkylene oxide and/or distillation of the hydroxyalkyl (meth)acrylate.
The liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. includes water, dimethyl sulfoxide, acetylacetone, acetaldehyde, acetone, acetonitrile, isobutyronitrile, ethanol, ethylene glycol, glycolonitrile, glycerin, o-chlorobenzonitrile, m-chlorobenzonitrile, succinonitrile, o-nitrotoluene, m-nitrotoluene, p-nitrotoluene, 1-nitropropane, 2-nitropropane, nitrobenzene, nitromethane, 1,4-butanediol, furfural, propiononitrile, benzonitrile, formamide, methanol, lactonitrile, and the like, preferably water, dimethyl sulfoxide, acetonitrile, furfural, benzonitrile and formamide, especially preferably at least one member selected from the group consisting of water, dimethyl sulfoxide and acetonitrile. In the case of a liquid having the relative dielectric constant of less than 20 at 25xc2x0 C., it is difficult to achieve the effect of the present invention, although the liquid is allowed to coexist at the time of the reaction between the (meth)acrylic acid and the alkylene oxide and/or distillation of the hydroxyalkyl (meth)acrylate.
In the case where a liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. is coexistent in a reaction liquid, the coexistence ratio of the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. per the reaction liquid is favorably in the range of 0.01 to 70 weight %, more favorably in the range of 0.1 to 50 weight %, especially favorably in the range of 1 to 40 weight %. When the coexistence ratio is less than 0.01 weight %, it is unfavorable because the formation amount of the diester increases, and when the coexistence ratio exceeds 70 weight %, it is unfavorable because the production efficiency deteriorates with the result that the production amount decreases or that it becomes necessary to enlarge production facilities.
Furthermore, in the case where the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. is coexistent in a liquid which is fed to the distillation apparatus, the coexistence ratio of the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. per the liquid which is fed to the distillation apparatus is favorably in the range of 0.01 to 70 weight %, more favorably in the range of 0.1 to 50 weight %, especially favorably in the range of 1 to 40 weight %. When the coexistence ratio is less than 0.01 weight %, it is unfavorable because the formation amount of the diester increases to bring about the deterioration of product quality and the fall of product purity, and when the coexistence ratio exceeds 70 weight %, it is unfavorable because the construction cost of facilities involved in the enlargement of the distillation apparatus increases.
Incidentally, a partial or full catalyst used for the reaction between the (meth)acrylic acid and the alkylene oxide may remain in the liquid which is fed to the distillation apparatus.
In the present invention, a mode that the reaction between the (meth)acrylic acid and the alkylene oxide is performed in the coexistence of the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C., or a mode that distillation of the hydroxyalkyl (meth)acrylate is performed in the coexistence of the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. is not especially limited, and examples thereof include (1) a mode that the reaction is performed after adding the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. on the occasion of adding reaction raw materials, (2) a mode that the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. is not coexistent in the reaction and distillation is performed after adding the concerned liquid in distillation, and (3) a mode that the reaction is performed after adding the liquid having the relative dielectric constant of not less than 20 at 25xc2x0 C. on the occasion of adding reaction raw materials and furthermore distillation is performed in the coexistence of the concerned liquid as it is.
(Effects and Advantages of the Invention)
A process for producing a hydroxyalkyl (meth)acrylate, according to the present invention, enables to control sufficiently the formation of a diester at the time of a reaction and/or at the time of distillation.


The following abbreviations and terms are herewith defined, at least some of which are referred to within the following description of the state of the art and the present invention.
3GPP 3rd Generation Partnership Project
ACL Access Control List
BFD Bidirectional Forwarding Detection
CS Circuit Switch
DA Destination Address
ICMP Internet Control Message Protocol
IMS IP Multimedia Subsystem
IM-MGW IP Multimedia Media Gateway Function
IP Internet Protocol
IPLx IP Level x
IPv4 IP version 4
IPv6 IP version 6
ISO International Organization for Standardization
LSP Label Switch Path
MGW Media Gateway
MPLS Multi-Protocol Label Switching
MSCS Mobile-Services Switching Center
NHR Next Hop Router
NUD Network Unreachability Detection
OSI Open System Interconnect
RFC Request for Comment
SA Source Address
TS Technical Specification
TTL Time To Live
Next Hop Router (NHR): The first router in the path from the host to the destination network.
IMS Network—IPv4 and IPv6
The IP Multimedia Subsystem (IMS) originally specified the use of the new IP version 6 (IPv6) technology and later allowed the legacy IP version 4 (IPv4), but the intent is to move forward with IPv6 communications. Hence, the network providers are requiring IPv6 interfaces with their IMS networks. However, the access nodes from the previous non-IMS technologies, e.g.:                Call Server, e.g., Mobile-Services Switching Center (MSCS)        Media Gateway (MGW)may or may not support native IPv6, and often do not. Thus, the CS's MSCS is having capabilities shown as MGCF added so it can interface with the IMS network. Likewise, the CS's MGW is having capabilities shown as IM MGW added so it can support the IMS Mn and Mb interfaces. FIG. 1 (PRIOR ART) is a diagram that illustrates the logical interfaces CS 102a and 102b respectively between the IMS network's IMS-MGW 104 and MGCF 106 and the CS network's MGW 108 and MSCS 110—this diagram is part of TS 23.228 3GPP; TS Group Services and System Aspects; IP Multimedia Subsystem (IMS); Stage 2 (Release 11), 2011-12 (the contents of which are incorporated herein by reference). In this case, IMS components, such as the Serving-Call Session Control Functions (S-CSCF) 112 and the Media Resource Function Processor (MRFP) 114 respectively communicate with the MGCF 106 and the IMS-MGW 104 using the IPv4 and/or IPv6 (preferred) protocols. These IP capable host devices—S-CSCF 112/MGCF 106 and MRFP 114/IMS-MGW 104—will communicate with each other over an IP capable network infrastructure composed of IP routers which are not shown in FIG. 1 because they are associated with physical connections rather than logical connections.
The IMS-MGW 104 and the MGCF 106 both require IPv4 and IPv6 capabilities and so that these devices can utilize the existing direct-connected IPv4 infrastructure they both implement an IPv4 to IPv6 transition technique known as tunneling. FIG. 2 (PRIOR ART) illustrates the IMS-MGW 104 and MGCF 106 which function as hosts interacting with their next hop routers 202 and 204 which are associated with the IMS subsystem IPv6 206 utilizing tunneling where IPv6 is tunneled over IPv4 so that the existing host IPv4 infrastructure does not change and the IPv6 is managed at the host's application end point. The next hop routers 202 and 204 are part of the aforementioned IP network infrastructure. The next hop routers 202 and 204 are capable of tunneling over IPv4 the native IPv6 traffic between the IMS components—S-CSCF 112/MGCF 106 and MRFP 114/IMS-MGW 104.
The Internet Protocol (IP) may utilize tunneling techniques to transport information for various reasons:                Security        IPv4 to IPv6 Transition        IPv6 to IPv4 TransitionPacket Encapsulation
FIG. 3 (PRIOR ART) illustrates how tunneling is realized by encapsulating a packet 300 with its original IP header 302 and data 304 within a new IP header 306 to form an encapsulated packet 308. The IP headers 302 and 306 may be any combination of IPv4 or IPv6. For instance, the original IP header 302 is an IPv6 IP header and the new IP header 306 is an IPv4 IP header, or the original IP header 302 is an IPv4 IP header and the new IP header 306 is an IPv6 IP header, or the original IP header 302 is an IPv4 IP header and the new IP header 306 is an IPv4 IP header, or the original IP header 302 is an IPv6 IP header and the new IP header 306 is an IPv6 IP header
Tunnel Endpoints
FIG. 4 (PRIOR ART) illustrates a tunnel 400 (which includes the encapsulated packet 308) with two tunnel end points 402a and 402b each represented by an IP address associated with each IP layer. For example, an IPv6 over IPv4 tunnel 400 would have both an IPv6 address (IP Level 2) 404a and 404b and an IPv4 address (IP Level 1) 406a and 406b at each tunnel endpoint 402a and 402b. In particular, the tunnel endpoint 402a would have an IP address L2a 404a and an IP address L1a 406a while the tunnel endpoint 404b would have IP address L2b 404b and IP address L1b 406b. The IP addresses 406a and 406b are used to route between a host (e.g., MGCF 106) and a router (e.g., router 204) as they are used in the outside new IP header 306 And, the IP addresses 404a and 404b are used to route between the host and the far end device (see FIG. 6). The word “level” is used herein to distinguish the different stacked IP headers and is not to be confused with the term “layer” which is used in the International Organization for Standardization (ISO) Open System Interconnect (OSI) 7-layer Reference Model.
Tunnels vs. Links
Tunnels may exist between a host and routers (host-routers) or between the routers themselves (router-router). An algorithm for tunneling IPv6 over IPv4 between a host-and-routers and between routers-and-routers is described in RFC 4213 “Basic Transition Mechanisms for IPv6 Hosts and Routers” October 2005 (the contents of which are incorporated by reference herein). The IP protocol operates at the Network Layer, or Layer 3, of the ISO OSI Reference Model. This implies that the tunnel operation is also at Layer 3.
As shown in FIG. 5 (PRIOR ART), the host 500 when connecting to next hop routers 5021 and 5022 (only two shown) usually utilizes redundant paths 5061 and 5062 to the adjacent routers 5021 and 5022 to ensure connectivity even if there is a single point of failure (see also FIG. 2). The host 500 has an algorithm 510 which determines which link or links are utilized when communicating via its adjacent routers 5021 and 5022 to the far end device 504. This algorithm 510 will therefore determine the physical path(s) 5061 and 5062 used for communicating via the adjacent router(s) 5021 and 5022 to the far end device 504. Note: the physical paths 5061 and 5062 along with their associated data link protocol operate at the Data Link (Layer 2) and the Physical (Layer 1) of the OSI model and are therefore segregated from the tunneling which operates at Layer 3.
The host 500 to survive a single point of failure needs a minimum of two paths 5061 and 5062 connected to the two routers 5021 and 5022. Although more paths and routers may be utilized, the two-path algorithm is generally deployed. The adjacent routers 5021 and 5022 generally have an inter-router link 512 (the link inter-connecting each of the adjacent routers 5021 and 5022) to provide alternative path routing for both ingress traffic and egress traffic with respect to the host 500 and the network (far end device 504).
As shown in FIG. 6 (PRIOR ART), there is a host-router configuration in which the host 500 inter-connects to its adjacent or next hop router 5021 (for example) using one network protocol “A”, e.g., IPv4, while an application 602 on the host 500 needs to communicate with another application 606 on the far end device 504 using a different network protocol B, e.g., IPv6. Thus, to allow the host 500 to communicate with the far end device 504 there is established a host-router tunnel 6041 which uses network protocol “A” with network protocol “B” embedded therein.
As shown in FIG. 7 (PRIOR ART), if a host-router tunnel is utilized, then the host 500 will need a tunnel 6041, 6042 . . . 604n to each of its adjacent routers 5021, 5022 . . . 502n. Note: that a tunnel, and its traffic, between two end points may utilize different physical paths over time.
Tunneling and Routing
Host-to-Router Direction
In the host 500 to router 5021 (for example) packet flow direction, the original IP header contains:                Destination IP Address—Far end device's address        Source IP Address—Host's address
The host 500 will encapsulate the original IP packet with a new IP header. The new IP header contains:                Destination IP Address—Router's Tunnel Endpoint Address        Source IP Address—Host's Tunnel Endpoint Address
Once the packet is removed from the tunnel by the router 5021, the external IP header is removed and the original IP header is then used to route the packet.
Router-to-Host Direction
In the router 5021 (for example) to host 500 packet flow direction, the original IP header contains:                Destination IP Address—Host address        Source IP Address—Originator of the IP packet (far end device 504)
The router 5021 will encapsulate the original packet with the tunnel header. The new IP header contains:                Destination IP Address—Host's Tunnel Endpoint Address        Source IP Address—Router's Tunnel Endpoint AddressTunnel Integrity Check
Tunnels 6041, 6042, 604n (for example) are effectively managed by software and are therefore subject to failure. The host 500 (for example) could check the tunnel's integrity by running heartbeat messages at the tunnel level. Examples of such a heartbeat mechanism 608 include:
Bidirectional Forwarding Detection (BFD):
                RFC 5880—Bidirectional Forwarding Detection (BFD), Standard, June 2010.        RFC 5881—Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop), June 2010.        RFC 5883—Bidirectional Forwarding Detection (BFD) for Multihop Paths, June 2010.        RFC 5884—Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs), June 2010.        RFC 5882—Generic Application of Bidirectional Forwarding Detection (BFD), June 2010.Internet Control Message Protocol (ICMP):        RFC 792—Internet Control Message Protocol, September 1981.        RFC 4443—Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification, March 2006.Network Unreachability Detection (NUD):        RFC 4861—Neighbor Discovery for IP version 6 (IPv6), September 2007.Note: The contents of these eight documents are hereby incorporated by reference herein.Time To Live (TTL) and Hop Limit
There is a field in the IPv4 header, Time To Live (TTL), and in the IPv6 header, Hop Limit, which ensures that a packet caught in a routing loop will eventually be discarded. Plus, when a router 5021, 5022 . . . 502n (for example) receives an IP packet, the router 502k, 5022 . . . 502n decrements the TTL/Hop Limit field. If the result is zero (0), then the packet is discarded.
Problems
The host 500 (for example) which has multiple tunnels 6041, 6042 . . . 604n one to each of its adjunct routers 502k, 5022 . . . 502n must know the operational status of each and every tunnel 6041, 6042 . . . 604n. Furthermore, the tunnels 6041, 6042 . . . 604n which are utilized for communications would depend on the Layer 1/2 active path(s) 5061, 5062 . . . 506n to gain the most efficient routing. This implies that the host's Layer 3 function would need to be cognizant of the Layer 1/2 functions which is not the intent of the ISO OSI Reference Model. This situation can be problematic because some tunnels 6041, 6042 . . . 604n may be intended to be active while others are standby, while some links 5061, 5062 . . . 506n may be intended to be active while other links are standby. And, if the active tunnels 6041, 6042 . . . 604n and the active links 5061, 5062 . . . 506n do not align, then less efficient routing will occur. Referring to FIGS. 8A-8D (PRIOR ART), there are shown two cases—FIGS. 8A and 8B—which lead to efficient routing and two cases—FIGS. 8C and 8D—which lead to less efficient routing. In FIG. 8A, the host 500 and routers 5021 and 5022 have active tunnels 6041 and 6042 and active links 5061 and 5062 which are synchronized resulting in efficient routing of packets. In FIG. 8B, the host 500 and router 5021 have an active tunnel 6041 and an active link 5061 which are synchronized resulting in efficient routing of packets. In FIG. 8C, the host 500 has an active tunnel 6041 and an active link 5061 with router 5021 and the host 500 has an active tunnel 802 but no active link with router 5022 which results in less efficient routing. In FIG. 8C, assuming that one tunnel is all that is needed by the host 500, then the active tunnel 6041 associated with the active link 8001 should be used which avoids the extra hop between the pair of routers 5021 and 5022. In FIG. 8D, the host 500 has an active link 5061 but no active tunnel with router 5021 and at the same time the host 500 has an active tunnel 802 but no active link with router 5022 which results in less efficient routing. Accordingly, there is a need to address these shortcomings and other shortcoming associated with the state-of-the-art.


1. Field of the Invention
The present invention relates to a multipolar electrical connector which is to be disposed on a memory card such as an IC card, in order to connect various devices mounted on the memory card with electronic circuits of a computer system.
2. Description of the Prior Art
Such a multipolar electrical connector for a memory card (hereinafter, referred to as merely "connector") is attached to the front end portion of the body of the memory card so as to be united with the body of the memory card. The connector has an electrically insulating body wherein a number of pin terminal insertion spaces into which pin terminals of a counter multipolar electrical connector (hereinafter, referred to as merely "counter connector") are to be respectively inserted are formed. In each of the pin terminal insertion spaces, a contact piece which functions as a contact and which corresponds to a pin terminal of the counter connector is housed.
Conventionally, connectors having such a configuration, are known, such as those shown in FIGS. 7 to 10. These have a number of contacts (number of contacting points) for pin terminals of a counter connector, and a positional relationship in the front-to-back direction between a contact with which a pin terminal of a counter connector contacts and the rocking fulcrum of a contact piece.
The connector shown in FIG. 7 comprises an insulating body A in which pin terminal insertion spaces B are formed. In each of the pin terminal insertion spaces B, a pair of plate-like elongated contact pieces C, C which extend in the pin terminal insertion and extraction direction X are symmetrically arranged. The contact pieces C, C are electrically connected with each other by a short-circuit portion D made of a thin metal plate. The short-circuit portion D and the paired contact pieces C, C are formed into one body by punching or bending a thin metal plate which is common to them.
The connector of FIG. 8 comprises a pair of contact pieces C, C and a short-circuit portion D which also are formed by punching a thin metal plate. The edge faces (which are formed as a result of a punching process of the thin metal plate) of the contact pieces C, C function as contacts F, F.
In the connector of FIG. 9, contacts F, F of paired contact pieces C, C are positionally shifted in the front-to-back direction, and the base portions of the contact pieces C, C are electrically connected with each other by a short-circuit portion D.
In the pair of contact pieces C, C used in the connectors of FIGS. 7, 8 and 9, the contacts F, F corresponding to a pin terminal G1 or G2 are at positions (given positions in the pin terminal extraction direction X1) which are located more forward than rocking fulcrums E, E respectively located in the base portions.
The connector shown in FIG. 10 is similar to that of FIG. 7 in that a pair of elongated plate-like contact pieces C, C extend in the pin terminal insertion and extraction direction X and are symmetrically arranged in each of the pin terminal insertion spaces B formed in the insulating body A, in that the contact pieces C, C are electrically connected with each other by a short-circuit portion D made of a thin metal plate, and in that the short-circuit portion D and the contact pieces C, C are formed into one body by punching or bending a thin metal plate which is common to them. In the connector shown in FIG. 10, however, contacts F, F corresponding to a pin terminal G1 or G2 are at positions (given positions in the pin terminal insertion direction X2) which are located more rearward than rocking fulcrums E, E respectively located in the base portions.
In FIGS. 7 and 10, B1 designates the body of the counter multipolar electrical connector.
A number of pin terminals of a counter connector disposed on a computer apparatus in which a memory card is to be used project from the connector body by lengths varying depending on the kind of signals to be processed. This is because, when the pin terminals of the counter connector are inserted into the pin terminal insertion spaces of a connector to connect the counter connector with the connector, the contact timings between the pin terminals through which signals of different kinds pass and the corresponding contact pieces of the connector are temporarily shifted from each other in accordance with the kinds of the signals.
The connector described in conjunction with FIG. 7 has higher reliability with respect to that, when the two kinds of pin terminals, the short pin terminal G1 and the long pin terminal G2 indicated by phantom lines in the figure are to be inserted, the timings of contacting the pin terminals G1 and G2 with the contacts F . . . of the corresponding contact pieces C . . . (the contact pieces corresponding to the long pin terminal G2 are not shown) are surely temporarily shifted from each other. More specifically, the pin terminal G1 collides with the contacts F, F immediately before the pin terminal G1 is inserted into the lap position of the paired contact pieces C, C (the position where the contact pieces C, C overlap with each other in the thickness direction T of the body A). It is impossible for the pin terminal G1 to contact any portion of the contact pieces C, C before the pin terminal G1 collides with the contacts F, F. This is applicable also to the long pin terminal G2. As a result, it is possible to assure the above-mentioned temporal shift between the contact timings.
However, the contacts F, F are located more forward than the rocking fulcrums E, E which are respectively located in the base portions of the contact pieces C, C. Accordingly, when, in the insertion process of the pin terminals, the short pin terminal G1 collides with the contacts F, F, for example, a part of the force generated by the collision is received by the rocking fulcrums E, E, whereby a large force is generated so as to impede the insertion of the pin terminal G1. This causes the force (insertion force) required for inserting the pin terminal G1 to be increased. Also for the long pin terminal G2, there arises the same situation as that of the short pin terminal G1. Since the pin terminals G1 and G2 respectively correspond to pairs of the contact pieces C, C and a number of the pin terminals G1 . . . and G2 . . . strike the corresponding contacts F . . . in the insertion process of a multipolar electrical connector, it is necessary to exert a large insertion force, whereby the operability in the insertion process is impaired. To comply with this, a configuration may be adopted in which a single contact piece is allocated to one pin terminal so that the operability in the insertion process is improved. In this configuration, however, each pin terminal contacts with only one contacting point, and therefore contact stability is lowered.
The connector described in conjunction with FIG. 8 has a configuration in which the contact pieces C, C are difficult to bend in the directions separating from each other. In this connector, therefore, the force of inserting the pin terminals may be larger than that in the connector of FIG. 7, so that operability in the insertion process is further impaired as compared with that of FIG. 7. Since the edge faces which are formed as a result of a punching process of a thin metal plate function as the contacts F, F, moreover, the maximum width of the contacts F, F is restricted to the thickness of the thin metal plate. When a pin terminal inserted between the contacts F, F is deviated with a somewhat large degree in the width direction of the contacts F, F (the thickness direction, or the direction perpendicular to the sheet in FIG. 8), therefore, it is not possible to absorb the deviation.
In the configuration of the connector described in conjunction with FIG. 9, when a pin terminal is inserted, the two contacts F, F sequentially collide with the pin terminal. Therefore, the operability in the insertion process is improved as compared with that of FIG. 7. In order to equalize the effective lengths L1 and L2 of the contact pieces C, C to each other while keeping the contact pressures against the pin terminal equal to each other, however, the contact piece C having the contact F which is located rearward must be shifted backward from the position of the contact piece C having the contact F which is located forward, by the distance corresponding to the shifting distance between the contacts F, F. This increases the whole length of the connector, thereby impeding the miniaturization.
In the connector of FIG. 10, the contacts F, F are located more rearward than the rocking fulcrums E, E which are located in the base portions of the contact pieces C, C. According to this configuration, when the short pin terminal G1 collides with the contacts F, F in the insertion process, for example, it occurs only that the paired contact pieces C, C swing about the respective rocking fulcrums E, E, and the situation that the force generated by the collision of the pin terminal G1 against the contacts F, F is received by the rocking fulcrums E, E does not occur. Accordingly, a large force of hindering the pin terminal from being inserted is not generated, and therefore the insertion force for the pin terminal G1 can be smaller than that required in the connectors of FIGS. 7 and 8. Also for the long pin terminal G2, there arises the same situation as that of the short pin terminal G1. Although the pin terminals G1 and G2 respectively correspond to pairs of the contact pieces C, C and a number of the pin terminals G1 . . . and G2 . . . strike the corresponding contacts F . . . in the insertion process of a multipolar electrical connector, therefore, the required insertion force is not so large and operability is hardly impaired.
However, the connector has the following drawback. When the two kinds of pin terminals, the short pin terminal G1 and the long pin terminal G2 indicated by phantom lines in FIG. 10 are to be inserted, it is difficult to assure the temporary shift between the timings of contacting the pin terminals G1 and G2 with the contacts F of the corresponding contact pieces C . . . (the contact pieces corresponding to the long pin terminal G2 are not shown). More specifically, the pin terminal G1 collides with the contacts F, F after the pin terminal G1 is inserted into the lap position of the paired contact pieces C, C. If the pin terminal G1 is bent, therefore, there may arise a situation whereby the short pin terminal G1 contacts the corresponding contact piece C before the long pin terminal G2 collides with the corresponding contacts F, F. When such a situation occurs, it is impossible to assure the temporary shift between the contact timings of contacting the pin terminals G1 and G2 of the two kinds with the contacts.
As described above, in a prior art multipolar electrical connector for a memory card, the temporary shift between the timings of contacting contacts with pin terminals having different lengths can be assured at the sacrifice of operability in the insertion process. Further, a prior art multipolar electrical connector has a problem in that the prevention of an impaired operability in the insertion process is liable to be conducted at the sacrifice of the reliability with respect to the assurance of the temporary shift between the contact timings. Moreover, a prior art multipolar electrical connector has another problem in that, when the assurance of the temporary shift between the contact timings is attempted without sacrificing operability in the insertion process, miniaturization is impeded or the reliability of the contacting states between contacts and pin terminals is lowered.