FIG. 1 diagrammatically illustrates a known stereoscopic display system comprising a stereoscopic display device in association with a complementary viewing device in the form of spectacles comprising two orthogonal polarisers intended to be disposed so that each polariser is positioned immediately in front of a respective eye of the viewer. The stereoscopic display device comprises a matrix of pixels half of which emit light polarised in a first direction and the other half of which emit light polarised in a second direction orthogonal to the first direction. For example the pixels may be arranged in columns and rows in the matrix, and alternate pixels or alternate rows or columns of pixels may be of the two different polarisation types. Thus the two eyes of the user see different images determined by switching of the pixels of the two polarisation types, and in this manner the viewer perceives a three dimensional scene. Ideally light pertaining to only one of the different images should be incident on each eye of the user over as broad a range of wavelengths as possible if the three-dimensional image is to be of the best quality.
Referring to FIG. 1, such a known stereoscopic display device may comprise a layer of liquid crystal material 1 confined between two transparent electrodes 2 and 3 one of which is shown divided into two regions A and B denoting two pixels of the device. Furthermore the electrodes 2 and 3 and liquid crystal material 1 confined therebetween are disposed between two linear polarisers 4 and 5 having polarising axes whose relative orientation is determined by the mode of switching of the liquid crystal material in the device. For example, the polarising axes of the polarisers are normally aligned perpendicular to one another in a twisted nematic liquid crystal display (TNLCD) device. As is well known, the liquid crystal material of the device acts as a pixelated optical shutter enabling the emission of light to be controlled on a pixel-by-pixel basis, and accordingly it is not necessary to describe the switching operation of such a device in detail.
In the particular arrangement which is diagrammatically shown in FIG. 1 the polariser 5, which is positioned in front of the liquid crystal material 1 and associated electrodes 2, 3, has its polarisation axis 11 disposed vertically. Furthermore an optical retarder in the form of a quarter wave plate 6 is positioned in front of the polariser 5 and comprises two differently patterned regions A' and B' having optic axes 12 and 13 oriented respectively at -45.degree. and +45.degree. to the polarisation axis of the polariser 5. Thus light transmitted by the pixel A emerges from the region A' of the quarter wave plate 6 circularly polarised in a right-handed direction, as shown by the arrow 7, and light transmitted by the pixel B emerges from the region B' of the quarter wave plate 6 circularly polarised in a left-handed direction, as indicated by the arrow 8.
In order to view a stereoscopic image, it is necessary to ensure that the viewer's left eye is only aware of light transmitted by pixels of one type, such as the pixel A, whilst being permanently unaware of the state of pixels of the other type, such as the pixel B, whereas the viewer's right eye is only aware of light transmitted by pixels of the other type, such as the pixel B, whilst being permanently unaware of the state of pixels of the one type, such as the pixel A. To this end, viewing spectacles with different polarising arrangements are placed immediately in front of the viewer's eyes, only the arrangement in front of the viewer's right eye 14 being shown in FIG. 1 for the purpose of illustration.
In this case the arrangement comprises an optical retarder in the form of a quarter wave plate 9 having its optical axis 15 parallel to the optic axis 13 of the region B' of the quarter wave plate 6, and a polariser 10 having its polarisation axis 16 orientated at 90.degree. to the polarisation axis 11 of the polariser 5. Thus the region B' of the quarter wave plate 6 and the quarter wave plate 9 having parallel optic axis 13 and 15 behave as a half wave plate with its optic axis orientated at +45.degree. to the polarisation axis 11 and disposed between the crossed polarisers 5 and 10, thus allowing the transmission of light from the pixel B to the viewer's right eye 14. On the other hand, since the region A' of the quarter wave plate 6 and the quarter wave plate 9 have crossed optic axis and are disposed between the crossed polarisers 5 and 10, light transmitted from the pixel A is cancelled almost completely at all wavelengths (assuming the quarter wave plates 6 and 9 are made of the same material so that they have the same dispersion characteristics) so that substantially no light reaches the viewer's right eye 14 from the pixel A. Such fully achromatic behaviour due to summing of the effect of optical retarders to zero retardation is known, for example, from U.S. Pat. No. 4,719,507.
Although not specifically shown in FIG. 1, it will be appreciated that the converse arrangement associated with the user's left eye comprises a quarter wave plate having its optic axis parallel to the optic axis 12 of the region A' of the quarter wave plate 6 and a polariser having its polarisation axis at 90.degree. to the polarisation axis 11 of the polariser 5. In this case such a quarter wave plate and the region A' of the quarter wave plate 6 having parallel optic axes behave as a half wave plate with its optic axis at -45.degree. between the crossed polarisers, and thus light transmitted from the pixel A reaches the viewer's left eye, whereas the crossed optic axes of the quarter wave plate and the region B' of the quarter wave plate 6 ensures that substantially no light from the pixel B reaches the viewer's left eye.
However the two sequential quarter wave plates which form a half wave retarder (unlike a zero wave retarder) only act in the required manner at a single wavelength, so that their transmission properties between crossed polarisers are chromatic, rather than achromatic. This can be seen from the graph of FIG. 2 showing the transmission level as a function of wavelength for the light received by the viewer's right eye 14 from the region B', after passing through the analysing polariser 10, and from the region A' of the quarter wave plate 6. Whilst the light from the region A' is cancelled substantially completely at all wavelengths, the light from the region B', after passing through the analysing polariser 10, is substantially unattenuated at only one wavelength (about 525 nm) whereas the light at over wavelengths is attenuated to a lesser or greater extent. Of course, the light received by the viewer's left eye will have a similar transmission profile but with A' substituted for B' and B' substituted for A' in FIG. 2.
Instead of having an achromatic dark state and a chromatic bright state as in the case of the graph of FIG. 2, it is possible for the device to be adapted to have a chromatic dark state and an achromatic bright state by providing a polariser 10 with a polarisation axis parallel to the polarisation axis 11 of the polariser 5. FIG. 3 is a graph of the transmission profile of the light received from the regions A' and B' of the quarter wave plate 6 by the viewer's right eye showing, as expected, the wavelength dependence of the light received from the region B'. Again the transmission profile of the light received by the viewer's left eye is similar with A' substituted for B' and B' substituted for A' in FIG. 3.
FIG. 4 shows a graph illustrating the light levels received from the regions A' and B' of the quarter wave plate 6 by the viewer's right eye, but with polycarbonate retarders being used to form a quarter wave plate 9 in each part of the viewing spectacles. Such polycarbonate retarders are more conventional, and thus less costly, for such use. The performance of the system is not greatly compromised by the use of polycarbonate retarders.
S. Pancharatnam "Achromatic Combinations of Birefringent Plates" Proceedings of Indian Academy of Sciences Vol. XLI, no. 4, Sec. A, 1955, pp. 130-136 and pp. 137-144 discuss the use of stacked uniform retarder films to improve achromaticity. However these papers are not specifically concerned with stereoscopic imaging systems.


For the design of digital circuits, designers often employ computer aided techniques. Standard languages, such as Hardware Description Languages (HDLs), have been developed to describe digital circuits to aid in the design and simulation of complex digital circuits. As device technology continues to advance, various product design tools have been developed to adapt HDLs for use with newer devices and design styles.
After the HDL code is written and compiled, the design of an integrated circuit (IC) or a system which includes multiple ICs must be verified to be correct. Continually advancing processing technology and the corresponding explosion in design size and complexity have led to verification problems for complex circuit designs, such as Application Specific Integrated Circuits (ASICs) that are difficult to solve using traditional simulation tools and techniques.
As a result, some designers build prototype boards using multiple ICs such as field programmable gate arrays (FPGAs) to verify their ASIC designs. However, there are still problems with debugging the hardware design. When an error is detected during debug, designers may attempt to tap signals of interest from the circuit and use a logic analyzer to determine the cause of the error. However, this is a difficult process and is often not effective, especially in the case of intermittent errors. Errors that have already occurred are often difficult to repeat and reconstruct.


FIG. 1A illustrates a conventional, prior art H-bridge inverter circuit 110 for transferring power from a DC supply 120 to an AC load 115. The H-bridge inverter circuit 110 includes four switches 111-114. During the operation of the H-bridge inverter 110, the switches 111-114 turn on and off in pairs to deliver an AC current to the AC load 115. For example, at one instance, switches 111 and 114 are turned on, while the switches 112 and 113 are turned off. Current flows from DC power supply 120 through switch 111, to the AC load 115, through the switch 114, and to a ground voltage or a negative supply voltage. At another instance, switches 111 and 114 are turned off, switches 112 and 113 are turned on. During this instance, the current flows from the DC supply 120 through the switch 113, to the AC load 115, through the switch 112, and to the ground voltage or the negative supply voltage. By altering the direction of the current flow, the H-bridge inverter is configured to deliver an AC current from the DC supply 120 to the AC load 115.
FIG. 1B illustrates a conventional, prior art sync bridge circuit 130 for transferring power from an AC supply 135 to a DC load 140. The sync bridge circuit 130 includes four switches 131-134. The sync bridge circuit 130 receives an AC current from the AC supply 135, and the switches 131-134 of the sync bridge circuit 130 turn on and off in pairs to deliver a DC current to the DC load 140.


This invention relates to hydraulic actuators for use in, e.g., robotic applications, and more particularly relates to force control of hydraulic actuators.
An actuator is generally defined as a device or mechanism that converts some form of energy into mechanical force or torque and linear or rotary velocity. A hydraulic actuator typically is connected to a high pressure fluid source and a flow control valve, e.g., a spool valve. Application of a small signal to the valve deflects the valve, allowing the fluid to flow, e.g., into one or more chambers driving a mechanical mechanism such as a piston provided in one or more of the chambers. With this action, the hydraulic actuator converts fluid flow into mechanical piston velocity, and provides the ability to control this velocity and corresponding mechanical position.
Hydraulic actuators are particularly well-suited for velocity and position control of robots and heavy equipment. Hydraulic systems also are generally characterized by the highest power density of modern controllable actuation systems because they are often operated at a pressure of as much as 3000 psi or greater. Hydraulic systems can also support large loads indefinitely while consuming minimal power. Given these attributes, hydraulic actuation systems are frequently the optimum choice for high force, high power density motion control applications such as automobile steering systems, airplane control surfaces, and heavy equipment operations employing, e.g., construction machinery.
While hydraulic systems are in many respects optimal for velocity and position control, a number of inherent hydraulic system limitations constrain their applicability for force control. For most applications, force control requires an ability to sense and correspondingly control the forces of interaction between an actuator and the actuation environment. But in hydraulic systems, a measurement of the primary system variable, hydraulic pressure, does not fully enable such. Specifically, the pressure in a hydraulic chamber, e.g., a piston chamber, is not in general a good representation of the force at the actuator output. Hydraulic systems are in general very sensitive to contamination, such as foreign particles, in the hydraulic fluid. In order to limit such contamination, it is preferable to employ tight fluidic seals at the hydraulic piston and cylinder. Tight seals are found, however, to typically produce substantial stiction and coulomb friction during sliding, and to require a very high breakaway force, all of which contribute to force noise at the hydraulic actuator output and thereby limit the ability to accurately estimate output force. Dynamically, a range of factors, including non-linear flow characteristics, can be very difficult to control.
There have been attempts to reduce the sliding friction and stiction characteristic of tight hydraulic seals by, e.g., reducing the piston seal tolerance. In one example alternative, two or more sets of loose seals are employed, the first seal allowing leakage from the supply fluid pressure chamber and the second and following seals scavenging the leakage. Although this configuration can improve sliding characteristics, it is not cost effective for most applications and in practice can be very prone to leaks. As a result, for most applications only tight hydraulic seals can be employed.
Given this fundamental difficulty in estimating the output force of a hydraulic actuator as function of hydraulic pressure, hydraulic actuators have been largely limited to velocity and position control applications. Implementation of force control for robotic and other applications in a manner that exploits the high power density of hydraulic actuation has heretofore not been fully practical.
The invention provides the ability to effectively and precisely implement closed-loop force control of a hydraulic actuator, provided in accordance with the invention as a hydro-elastic actuator. The hydro-elastic actuator of the invention includes a hydraulic actuator, having a connection to hydraulic fluid and including a mechanical displacement member positioned to be mechanically displaced by fluid flow at the actuator. A valve is connected at the hydraulic actuator connection and has a port for input and output of fluid to and from the valve. At least one elastic element is provided in series with the mechanical displacement member of the hydraulic actuator and is positioned to deliver, to a load, force generated by the hydraulic actuator. A transducer is positioned to measure a physical parameter indicative of the force delivered by the elastic element and to generate a corresponding transducer signal. A force controller is connected between the transducer and the valve to control the valve, based on the transducer signal, for correspondingly actuating the hydraulic actuator and deflecting the elastic element.
The hydro-elastic actuator of the invention can be configured such that the force controller is connected to accept an input indicative of a desired actuator output force to be delivered to the load. Here the force controller is connected between the transducer and the valve to control the valve based on the transducer signal and the input, for correspondingly actuating the hydraulic actuator by an amount that delivers to the load the a desired actuator output force.
The hydro-elastic actuator of the invention provides the ability to make a high-fidelity measurement of the output force of a hydraulic system without measuring pressure or flow characteristics of the hydraulic system. The feedback control loop enables precise hydraulic system force control and control stability to a level not previously achievable without complicated control schemes to accommodate hydraulic characteristics. The high power and high force generation capabilities of the hydraulic actuator are preserved while providing shock tolerance and low system output impedance.
The hydro-elastic actuator of the invention is well-suited for an extremely broad range of applications, and is particularly effective at addressing high-force, high-power density applications. Robotics applications and heavy equipment operations, such as robotic fire fighting and earth moving, as well as telerobotic and haptic systems, are particularly well-addressed. Further, the important and growing class of biomimetic robots, and particularly dynamically-stable legged robots, which primarily rely on force control-based locomotion algorithms, are enabled by the invention to take on mass and scale not previously attainable.
In accordance with the invention, the hydraulic actuator can be provided as a hydraulic actuation chamber in which the mechanical displacement member is disposed with respect to the fluid connection. Here the fluid connection preferably consists of a fluid inlet and a fluid outlet of the chamber. This enables control of displacement of the displacement member by fluid flow into and out of the chamber. The valve can be connected to the fluid inlet and fluid outlet, and preferably is provided as a flow control valve. Whatever connection is employed between the valve and the fluid inlet and outlet, it preferably is dimensionally fixed. The valve port can include a connection for receiving fluid pumped by a fluidic pump.
In embodiments of the invention, the valve control signal is based on proportional or proportional-integral control of actuator output force. The valve control signal is in one embodiment an electrical current. This electrical control current is directed to the valve and is indicative of a controlled fluid flow to be produced through the valve. The electrical control current can be indicative of a controlled bi-state valve operation between a state of zero fluid flow and a state of maximum fluid flow through the valve. The force controller can further be connected to produce a fluid source control signal directed to a fluid source connected to the valve port. Here the fluid source control signal can be indicative of a controlled pulsed delivery of fluid to the valve in synchrony with the bi-state valve operation.
In accordance with the invention, the hydraulic actuator, when provided as a chamber, can consist of a linear piston chamber having a linear piston and a piston push rod extending out of the chamber, a rotary piston chamber having a rotary vane and a rotary shaft extending out of the chamber, or other suitable chamber configuration. When employed, a piston can be double- or single-acting. Preferably either a substantially non-leaky seal is provided at a location where the piston push rod or shaft extends out of the chamber or alternatively, at least one leaky seal and at least one leakage scavenger seal can here be employed.
In embodiments of the invention, the elastic element can be provided as a linear or a nonlinear elastic element. The elastic element can be provided specifically as at least one spring disposed in series with the hydraulic actuator displacement member, or as a plurality of springs positioned to together result in an elasticity provided in series with the hydraulic actuator displacement member. One or more coupling elements can be provided in series with and between the elastic element and the hydraulic actuator displacement member, as well as in series with and between the elastic element and the load.
The transducer can be provided as a potentiometer, a strain gauge, or other suitable sensing configuration, e.g., as a magnetic position sensor or an optical position sensor. In one embodiment, the transducer signal is based on deflection of the elastic element.
The hydro-elastic actuator of the invention can be produced of lightweight, low-cost, easily manufactured components. The elastic element force feedback control of the system preserves the high power and high force or torque generation of the system while providing precise force control and good force control stability. These characteristics are ideal for robotic and other mechanistic systems that interact with their environment. Other applications, features, and advantages of the invention will be apparent from the following description and associated drawings, and from the claims.


A typical door hinge for use on an entrance door has a pivot or knuckle from one side of which extends a leaf attached to the door jamb and from the other side of which extends a leaf fixed to the door so that the door can pivot relative to the jamb about a normally vertical axis. In DE 10 2004 016 769 one of the leaves is simply screwed to the door and the other leaf is formed as a comb and fitted to a holder in turn set in a housing recessed in the jamb. The holder can be shifted relative to the housing for adjustment of the hinge.
In line with known approaches, the housing is fastened to the door frame. The door hinge has a comb-like free hinge leaf that is inserted into the holder of the housing, which is fastened to the door jamb and is permanently fixed thereto. The holder has a fixing plate as well as a clamping plate and is guided on spindles. By turning the spindles, the position of the holder is modifiable relative to the housing that constitutes the mounting part. The constructive design allows the door to be adjusted from side to side, that is horizontally. In addition, the position of the hinge leaf can be corrected horizontally and vertically within the holder before the hinge leaf is secured in place in the desired position between the clamping plate and the fixing plate. The known housing requires a dimensionally stable support to mount the adjustment spindles. The fixing plate and clamping plate to secure the hinge leaf must be of solid construction to as to be able to hold the weight of the door. Construction of the housing is costly and requires an installation space with a depth of 22 to 25 mm.
DE 199 21 796 describes a door hinge with a holder for receiving a hinge tab clamped between a tensioning plate and a clamping plate of the holder. For position adjustment of the holder, a spindle is provided that extends through a recess of the hinge leaf without rotational contact.


JP 3315993 B2 discloses a pant-type diaper comprising a liquid-pervious inner sheet, a liquid-impervious outer sheet and an absorbent structure sandwiched between these sheets. The diaper includes a front waist region adapted to lie on the wearer's ventral side and a rear waist region adapted to lie on the wearer's dorsal side. Transversely opposite side edges of the front waist region are joined to the associated side edges of the rear waist region so as to define a waist-opening and a pair of leg-openings. This diaper includes waist elastic members attached along a periphery of the waist-opening, and a waist-cuff extending, on the side of the diaper facing the wearer's skin, from the waist-opening toward the crotch region.
In this diaper, the waist-cuff is provided with an elastic member so that the waist-cuff may be put in close contact upon contraction of the elastic member so as to define a pocket between this waist-cuff and the diaper chassis and thereby to prevent body waste from leaking beyond the waist-opening.
In this diaper, the waist-cuff is left free from the diaper chassis except along the periphery of the waist-opening and at the transversely opposite ends of the front and rear waist regions. As a consequence, the pocket is apt to be deformed or even to be collapsed as the wearer's body moves, causing the body waste having been captured by the pocket to leak out from the diaper.
JP 4215370 B2 discloses a further diaper in which the waist-cuff is fixed to the diaper chassis in the vicinity of transversely opposite side edges of an absorbent structure. In this diaper, therefore, the shape retention of the pocket is correspondingly improved so that the pocket is not easily collapsed.
JP 4215370 B2 further discloses a diaper provided with leg cuffs formed along the transversely opposite side edges of the absorbent structure.
When the absorbent structure absorbs or receives body waste, the absorbent structure is drawn downward under a weight of body waste absorbed or received by the absorbent structure. Therefore, the waist-cuff might be drawn apart from the wearer's skin under a weight of body waste absorbed or received by the absorbent structure when the waist-cuff is fixed to the chassis in the vicinity of the absorbent structure.
When the diaper has a pair of leg-cuffs, the waist-cuff might partially overlap the leg-cuffs. In such diaper, if the waist-cuff is fixed in the vicinity of the side edges of the absorbent structure, the leg-cuffs may be collapsed to cause a leaking of body waste. Alternatively, the waist-cuffs might not overlap the leg-cuffs. In such diaper, there might be regions without both leg-cuffs and waist-cuff where leakage of body waste might occur.


1. Field of the Invention
The present invention relates to apparatuses and methods for forming workpieces, and particularly to apparatuses and methods that readily and accurately perform a variety of forming operations on metallic workpieces.
2. Related Art
With incessant development of modern manufacturing industries, more and more components having a myriad of different shapes are being required. Shapes commonly found on such components include, for example, inclined surfaces, arcuate surfaces, and steps. A variety of apparatuses and methods are available for forming such components.
Conventional apparatuses and methods for forming workpieces only allow the workpiece to be machined linearly. Arcuate surfaces are often formed using electrodischarge machines. However, electrodischarge machine is complicated and time-consuming. Furthermore, a special electrode is required for every different workpiece. This is unduly costly. Moreover, it is difficult to control the precision with which an electrodischarge machine forms a workpiece. Thus quality control of the workpieces is problematic.
An improved apparatus and method for forming workpieces which overcomes the above-mentioned problems and shortcomings is desired.
Accordingly, an object of the present invention is to provide an apparatus which can readily and accurately form a surface having three dimensions on a metallic workpiece.
Another object of the present invention is to provide a method which can efficiently and accurately form a surface having three dimensions on a metallic workpiece.
To achieve the above-mentioned objects, a forming apparatus in accordance with the present invention comprises a workbench and a pivot device. The workbench comprises a magnetic base for holding a workpiece thereon. The pivot device comprises a pivot plate and a fixed plate. The pivot plate is fixedly attached below the base, and rotatably seated on the fixed plate. The fixed plate defines a pair of cutouts in two corners thereof respectively, to form an arched-shaped top portion. A pair of locking plates is attached on a first side wall of the pivot plate, and another locking plate is attached on a second side wall of the pivot plate. When the locking plates are oriented vertically, bottom extremities of the locking plates are located between a top extremity of the top portion and a bottom extremity of the top portion. The locking plates can therefore pass over the two corners corresponding to the cutouts, but cannot pass over other corners of the fixed plate. When the locking plates are oriented horizontally, the bottom extremities of the locking plates are higher than the top extremity of the top portion. The locking plates can therefore pass over every corner of the fixed plate. By adjusting orientations of the locking plates, the combined base and pivot plate can be rotated within a variety of predetermined different angles.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of preferred embodiments of the present invention with attached drawings, in which:


1. FIELD OF THE INVENTION
The present invention relates to a focus condition detecting the device for a camera which detects focus condition of an objective lens of a camera from an object light having passed through the object lens.
2. DESCRIPTION OF THE PRIOR ART
There has been known a focus condition detecting device in which two images are formed by refocusing light bundles of an object light having passed through first and second areas of an objective lens which symmetric with respect to the optical axis of the objective lens. A relative distance between these two images is calculated and a defocus amount of the focus position from a predetermined focus position and a direction of the defocus are determined based on the relative distance calculated.
A typical optical system for such a focus condition detecting device as mentioned above is shown in FIG. 1.
In this system, a condenser lens 6 is usually arranged on a predetermined focal plane 4 of an objective lens 2 or on a plane positioned behind the focal plane and two refocusing lenses 8 and 10 are arranged rearside of the condenser lens 6. There are also arranged two image sensors 12 and 14 on each of focal planes of two refocusing lenses. Each of the image sensors 12 and 14 is comprised of a CCD (charge coupled device) image sensor having a plurality of light sensing elements.
The condenser lens 6 is so designed that effective ranges of the first and second refocusing lenses 8 and 10 can be projected within the exit pupil of the objective lens in order to form first and second images by light bundles having passed through the exit pupil and first and second refocusing lenses.
As shown in FIG. 2 schematically, when an image (A) of an object is focused frontside of the predetermined focal plane 4, two images a and a' are formed on the image sensors 12 and 14 so as to approach to each other with respect to the optical axis 18 of the objective lens. On the contrary to the above, when an image (B) of an object is focused rearside of the predetermined focal plane 4, two images b, b' are formed apart from each other. If an image is focused just on the predetermined focal plane 4, a distance between two corresponding points of the two images formed on two image sensors 12 and 14 becomes a specific value which is determined by the composition of the optical system of the focus condition detecting device. Accordingly, a focus condition of the objective lens can be determined from the distance between two corresponding points of the two images formed on the image sensors 12 and 14.
The detection of the distance mentioned above can be made as follows.
FIG. 3 shows a principle of operation therefor schematically. As shown therein, the first and second image sensors 12 and 14 are comprised of ten and sixteen cells of photodiodes (a.sub.1, . . . , a.sub.10) and (b.sub.1, . . . , b.sub.16), respectively. Now, assume that each symbol of an individual cell represents each output thereof. Considering now sets each of which is comprised of ten successive cells included in the second image sensor, seven sets B.sub.1, B.sub.2, . . . B.sub.7 can be obtained as shown in FIG. 3. The focus condition can be sought by calculating an individual correlation relation between the image received by ten cells of the first image sensor 12 and the image received by each of seven sets of the second image sensor 14.
Namely, correlation calculations are made with use of correlation functions: ##EQU1##
For example, if the image detected by the first sensor 12(A.sub.1) coincides with the image detected by the first set B.sub.1 of the second image sensor 14, the correlation function S.sub.1 becomes minimum among seven correlation functions S.sub.1, S.sub.2, . . . , S.sub.7. When either one set of the second sensor is found which gives the minimum value with respect to these correlation functions, the distance between two images is determined from the number of the set having been found minimum and a focus condition is detected based on the distance determined. These calculations are carried out by a correlation calculation means 16.
In FIG. 4 showing one scene viewed through a view-finder of a camera, the focus detection area A is limited to a relatively narrow center area of the field of view of the objective lens. In this case, the image of one person (main object) existing near to the camera and the background image comprised of trees and a hill ar entered into the focus detection area A and, due to this situation, the focus condition detecting device is liable to detect an intermediate distance between the person and the background as a correct distance of the object.
Meanwhile, in the case that a few objects having different distances from the camera respectively are entered into the focus detection area, the main object usually exists at a position nearer than those of the sub objects (background) and, usually, may be one or more persons. And the sub object is usually a background of the person. Considering such an ordinary or typical object as mentioned above, the image of the main object such as a person or persons has a contrast higher than that of the background usually.
In Japanese patent laid open publication No. 126517/1984, there is proposed a focus detecting device in which the focus detection area is divided into a plurality of blocks and a focus detection operation is carried out in every block and the credibility about individual focus detecting operation in every block is checked and the result obtained through the focus detecting operation having the highest credibility is employed as focus detection data.
However, according to this focus detecting device, a long calculation time is needed sine the credibility of focus condition detection has to be checked at every block divided.


1. Field of the Invention
The present invention relates to a racing type pedal, and more particularly to a racing type pedal for a bicycle.
2. Description of the Related Art
In general, the racing type pedal for a bicycle includes a road-use pedal and a mountaineering pedal, and the two different types of pedals need to mate with two different types of shoes and snap blocks. In practice, the snap block is mounted on the bottom of the bicycle shoe and snapped onto the bicycle pedal to secure the bicycle shoe on the bicycle pedal.
A conventional racing type pedal 3 in accordance with the prior art shown in FIGS. 10 and 11 comprises a main body 30, a hollow pivot hook 31 pivotally mounted on the main body 30 by a pivot shaft 32 and having a side formed with a vertical plate 310 having a through hole 3101, an adjusting bolt 34 mounted on the plate 310 of the pivot hook 31 extended through the through hole 3101 of the plate 310 of the pivot hook 31, a press block 35 mounted on the distal end of the adjusting bolt 34, and two torsion springs 33 each mounted on the pivot shaft 32 and each having a first end 330 urged on a block 301 of the main body 30 and a second end 331 urged on the press block 35.
However, when the adjusting bolt 34 is rotated to move the press block 35 to adjust the torque of the pivot hook 31, the adjusting bolt 34 and the press block 35 are subjected to a shearing force applied by the torsion springs 33, so that the adjusting bolt 34 is easily deflected from the press block 35 during movement, thereby disengaging or wearing the adjusting bolt 34 and the press block 35. In addition, the plate 310 of the pivot hook 31 is subjected to a force applied by the adjusting bolt 34, so that the plate 310 of the pivot hook 31 is easily distorted or deformed due to the applied force during a long-term utilization.


Portable, mobile computers such as slate computers have been used in business. The mobile computers are likely to be lost or stolen. Some of the mobile computers, therefore, have a function of deleting data in a terminal by remote control when it is lost or stolen (hereinafter, referred to as a remote wipe).
A remote wipe performed when a mobile computer is lost or stolen has a problem that the probability of success is low for such a reason that the computer is not connected to a network, and whether or not the remote wipe has succeeded cannot be determined.


The invention relates to a line-voltage-operated incandescent lamp having
a translucent lamp vessel sealed in a vacuum-tight manner; PA0 current supply conductors entering through the wall of the lamp vessel and mechanically interconnected inside the lamp vessel by means of glass beams with which they constitute a frame; PA0 a filament comprising several helically wound sections which are stretched at least substantially parallel to each other in the frame, each end of the filament being electrically connected to a respective current supply conductor; and PA0 two sets of supports which are anchored in a respective glass beam of the frame. Each support consists of a wire terminating in a hook and each hook engages the filament between a respective pair of adjacent sections of the filament.
Such a lamp is known from British Patent Specification 2,069,233 to which U.S. Pat. No. 4,367,428 corresponds.
The known lamp has a frame of a rigid construction, as a result of which the lamp is capable of withstanding shocks. In this respect, the known lamp is superior to lamps which were previously commercially available, in which two tungsten wires are anchored each with one end in one of the glass beams of the frame, while the other end of these wires is helically wound and grips around a respective current supply conductor and is fixed thereto. In these commercially available lamps, the length of the frame and hence the stress in the filament can be readily adjusted by slipping the helically wound ends further or less far over the current conductors, but the frame is not very capable of withstanding shocks.
In the manufacture of the lamp according to the that British Patent Specification, it has proved to be difficult to mount the filament with the correct tension in all its sections.


In sports that utilize equipment having an elongated shaft, the shaft must ideally be both lightweight and strong. However, these two requirements are often incompatible, in that reduction in weight often may cause a loss of strength and vice versa. Ideally, a shaft should have sufficient strength to withstand the stresses and deformation that arise during use and the impacts that it may be subjected to during play. This is particularly true in contact sports such as ice hockey, field hockey, lacrosse, ringuette, and others. Ideally, the elongated shafts used in those sports, must be able to withstand a large number of impacts, which impacts may often be concentrated at the edges, i.e. the corners or angles thereof formed by the meeting of two adjacent lateral sides of the shaft which, over time, may result in increased damage to the structure of the shaft and ultimately, premature failure thereof. The same concerns apply to the blade of a stick, which is subjected to many impacts, particularly on the upper surface.
Hockey sticks (including goalie sticks), field hockey sticks, lacrosse sticks, ringuette sticks and other such sports sticks may have shafts which may be made from a variety of materials including wood, aluminum, plastic and composite materials such as fiberglass, graphite and Kevlar™ or a combination of any of them. Some shafts are full (i.e not hollow), while others comprise four (relatively) thin side walls forming a peripheral box having a hollow core. Most blades are full, i.e. not hollow. Alternatively, some shafts and some blades have a composite construction having various layers of materials sandwiched as a core. Materials are usually selected for their physical properties in an attempt to improve performance, longevity, etc. . . . Some composite shafts may have lower durability, but are still popular because of their light weight and superior stiffness. Wood shafts are cheap, but are not especially light, stiff or durable while aluminum shafts can have a relatively short life as they are prone to bending failure. Cost is often a criterion in material selection. All of these shafts may be particularly vulnerable to failure along their edges, i.e. where one side surface intersects with an adjacent side surface, often at 90°. Impacts are often concentrated at these edges, precisely where there is less material to absorb and dissipate said impacts. The same problem is experienced by the blades. Lastly, sticks that are the subject of repeated impact on their edges rapidly become worn and tired-looking, with paint and decals worn off, and nicks and gouges therein. Some players do not like their equipment looking shabby.
There is therefore a need for a sports apparatus shaft that has an increased ability to withstand impact along its edges.
Accordingly, it is an object of the present invention to provide a sports shaft where there is provided added protection at the edges thereof.
It is another object of the present invention to provide a sports shaft where there is removed some material along at least one longitudinal edge thereof, which material is replaced with another material more suited for absorbing and resisting impacts.
It is another object of the present invention to provide a sports shaft where the shape of the shaft is such that grooves are provided along at least one of the edges so as to provide a volume to be filled with a material more suited for absorbing and resisting impact.
It is another object of the present invention to provide a blade shaft wherein at least one groove is provided along the upper edge so as to provide a volume to be filled with a material more suited for absorbing and resisting impact.
An additional object of the present invention is to provide a sports shaft wherein bumpers are selectively provided on the edges thereof to absorb and distribute the shock of an external impact, ideally in a direction perpendicular to the line of action of impact.
An additional object of the present invention is to provide a sports shaft wherein said bumpers are made from an elastomeric material.


1. Field of the Invention
The present invention relates generally to file systems, and in particular, to a method, apparatus, and article of manufacture for solving the difficulty incurred by a program on one computer (the client) being completely reliant on the internal file structure of another computer (the server) in order to access the server's files.
2. Description of the Related Art
Computer use has proliferated and continues to expand as technological capabilities rapidly increase. With this proliferation, the development and use of different computers running different types of operating system having different internal file systems has also increased. In a network environment, the different computers may attempt to communicate with each other including transmitting/receiving information and services to/from each other. However, when a computer program attempts to access a file on any other particular computer, the computer program is subjected to the quirks of the file system upon that computer. This includes the fact that the program trying to access the file needs to know both the name of the file, and where the file actually resides internally on the computer. Such information may not be known or may be difficult or impossible to learn and/or use. Accordingly, a method is needed for accessing information on files without knowledge of a computer's underlying file structure. These problems may be better understood by describing prior art file systems and network communications.
Depending on the type of operating system a computer is executing, the internal file system varies considerably. For example, if a computer is running the Windows™ operating system, the file system may be composed of one or more drives; either local within the computer or logically mapped to a network connection. Each drive is assigned a letter, starting from C (A and B are reserved) and ending at Z, followed by a colon (:) character. Within a given drive exists a hierarchical directory structure, using variable length names and the backward slash (\) character to indicate a level in the hierarchy. Examples of a hierarchical directory structure in the Windows operating system include those illustrated in Table 1:
TABLE 1C:\TempA directory name called Temp located onthe C drive.C:\Temp\FredA directory called Temp further containinga sub-directory called Fred.C:\Temp\Fred\file.txtA file residing in the Fred sub-directory ofthe Temp directory.
If a computer is running the UNDX™ operating system, the file system is composed of one or more “mount” points; either local within the computer or logically mapped to a network connection. Each mount point is assigned a name, and is referenced using two forward slashes (//). Within a given mount point exists a hierarchical directory structure, using variable length names and the forward slash (/) character to indicate a level in the hierarchy. Examples of a hierarchical directory structure in the UNIX™ operating system include those in Table 2:
TABLE 2//TempA directory name called Temp located onthe default mount point.//Temp/FredA directory called Temp further containinga sub-directory called Fred.//Temp/Fred/file.txtA file residing in the Fred sub-directory ofthe Temp directory.
If a computer is running the OS/390™ operating system, the file system is composed of one or more high-level prefix names that are controlled by a central catalog. Beneath the high level prefix lies one or more 1 to 8 character names, separated by a period (.) character, with a total length not exceeding 44 characters.
The combination of high-level prefix and the period-delimited suffix is called a “dataset name”. There are many types of datasets on OS/390. Each of the datasets further complicates the indicated format. One of the more common datasets is called a Partition Dataset or PDS. A PDS may contain one ore more files, indicated by use of open and close parentheses ( ). Examples of a hierarchical data structure in the OS/390 operating system include those illustrated in Table 3:
TABLE 3HILEV.temp.fred.FileA dataset containing many files.HILEV.temp.fred.File(txt)A dataset name calledHILEV.temp.fred.file containing a filecalled txt.
The details of the file systems are not necessary for understanding the present invention. However, it should be recognized that the file systems are all different. In this regard, a computer program trying to access a file on any particular computer is subjected to the quirks and details of the file system upon that computer. Such details include the fact that the program trying to access the file needs to know both the name of the file, and where the file actually resides internally on the other computer.
The prior art necessity for knowledge of the file system details may be illustrated by the following example. Assume three different computers (servers) are communicating: one running OS/390, one running Windows™, and the third one running UNIX. Each server houses a copy of a file. In each case, the file is the same in the sense that its content is identical. It is only the file system upon which the file resides that varies from one machine to the next.
A fourth computer, acting as a client, wishes to retrieve this file from any server. The client does not care which server it retrieves the file from, since the file will be the same no matter which server handles the request. Thus when the client connects with the server, it wishes to merely “ask for the file” without the need to care about the server's file system. To paraphrase in English, the client request may be “Excuse me server, could you please give me file X?” as distinct from “Excuse me server, could you please give me file X which you have located in quadrant Y of partition Z on drive Q?”
When considering the second request above, it should be clear that the client would not know that this particular server uses the term “quadrant” while a different server may use the term “directory” while the third server may use the term “fandangle”. Furthermore, even if the client could be made to be completely sensitive to the server's file system and know the proper form for requesting a file (e.g., the client speaks in the vocabulary of the server), the client would not know where the file actually was located. In other words, the client request may be “Excuse me server number 2, I speak your language, so could you please refer to drive C, directory Alpha, delimiter ‘\’, sub-directory Beta, and send me a copy of file X?” In response, the server may return the file to the client. However, to personify the server with human emotion, the server may respond: “Hello Client, yes here is file X, but how did you know where I had it located?”
In view of the above, it may be understood that a program trying to access a file in the prior art needs to know both the name of the file and where the file actually resides internally on the other computer. Gaining and maintaining such knowledge is problematic.


Conventionally, as a means of displaying images, projection-type optical display apparatuses such as projectors are known. Such optical display apparatuses require an optical illumination apparatus for efficiently and uniformly illuminating the optical image formed on a display panel, such as a reflective liquid crystal display panel. FIG. 10 is a diagram conceptually showing an example of the construction of an optical display apparatus employing a conventional optical illumination apparatus.
In FIG. 10, reference numeral 101 represents a light source, and reference numeral 102 represents a reflector disposed so as to partially surround the light source 101. A PBS (polarizing beam splitter) prism unit 103 is disposed immediately behind the reflector 102, i.e., on the right side thereof in FIG. 10. The PBS prism unit 103 includes a plurality of PBS prisms arranged parallel to one another. The PBS prism unit 103 splits the light from the light source 101 into two differently polarized types of light. Of the individual PBS prisms 103a and 103b, those which let out S-polarized light as described later have half-wave plates 104 disposed immediately behind them.
Behind the PBS prism unit 103 (i.e., on the right side thereof in FIG. 10) are disposed, in order of arrangement, a first lens array 105, then somewhat away therefrom, a second lens array 106, and a superimposing lens 107 immediately behind it. The first lens array 105 has a plurality of lens cells 105a arranged in a rectangular, grid-like array having an aspect ratio substantially identical to that of a display panel 109 to be described later. Similarly, the second lens array 106 also has a plurality of lens cells 106a arranged in a rectangular, grid-like array. However, the shape of the lens cells 106a of the second lens array 106 is not necessarily geometrically similar to that of the lens cells 105a.
The images from the individual lens cells 105a of the first lens array 105 are, by the second lens array 106 and the superimposing lens 107 disposed immediately behind it, superimposed on one another in the vicinity of the focal point of the superimposing lens 107. The display panel 109 is disposed at the focal point of the superimposing lens 107. The display panel 109 is illuminated in a telecentric fashion by a condenser lens 108 disposed immediately in front of it. The components from the first lens array 105 through the superimposing lens 107 mentioned above together constitute an optical integrator system. It is to be noted that, in all the diagrams referred to in the present specification, irrespective of whether they relate to prior-art examples or to embodiments of the present invention, light beams are represented by their optical axes alone.
The light emitted from the light source 101 is reflected from the reflector 102, and is thereby formed into a substantially parallel beam and directed to the PBS prisms 103a of the PBS prism unit 103. Here, P-polarized light, indicated by solid lines P, is transmitted straight through the PBS prisms 103a. On the other hand, S-polarized light, indicated by broken lines S, is reflected inside the PBS prisms 103a so as to be directed to the outwardly contiguous PBS prisms 103b, and is then reflected again inside the PBS prisms 103b so as to exit therefrom, still as S-polarized light. That is, by the PBS prism unit 103, the light from the light source 101 is split into two differently polarized types of light in the direction of the longer sides of the display panel 109, i.e., in a vertical direction along the plane of the figure.
The S-polarized light exiting from the PBS prisms 103b is transmitted through the half-wave plates 104 disposed immediately behind the PBS prisms 103b and is thereby converted into P-polarized light. That is, a portion of the light from the light source 101 has its polarization converted first by the PBS prisms 103b of the PBS prism unit 103 and then by the half-wave plates 104, and eventually comes out as uniformly P-polarized light. This arrangement constitutes a polarization conversion device. Here, the type of light into which the light from the light source 101 is converted does not necessarily have to be P-polarized light, but can be of other polarizations. The arrangement described thus far, starting with the light source 101 and ending immediately in front of the display panel 109, constitutes an optical illumination apparatus.
The light thus converted into uniformly P-polarized light is then directed through the above-mentioned optical integrator system to the display panel 109. The display panel 109 modulates, pixel by pixel, the light it is illuminated with according to the display data fed thereto, and emits the modulated light. The light thus emitted then enters an optical projection system 110. The display data presented on the display panel 109 is projected, as an image, onto a screen (not shown) through this optical projection system 110. Reference numeral 110a represents an aperture stop disposed in the optical projection system 110.
FIG. 11 is a diagram conceptually showing another example of the construction of an optical display apparatus employing a conventional optical illumination apparatus. In this figure, reference numeral 201 represents a light source, and reference numeral 202 represents a reflector disposed so as to partially surround the light source 201. Behind the reflector 202 (i.e., on the right side thereof in FIG. 11) are disposed, in order of arrangement, a first lens array 203 and, then somewhat away therefrom, a second lens array 204. The first lens array 203 has a plurality of lens cells 203a arranged in a rectangular, grid-like array having an aspect ratio substantially identical to that of a display panel 209 to be described later. Similarly, the second lens array 204 also has a plurality of lens cells 204a arranged in a rectangular, grid-like array. However, the shape of the lens cells 204a of the second lens array 204 is not necessarily geometrically similar to that of the lens cells 203a.
A PBS (polarizing beam splitter) prism array 205 is disposed immediately behind the second lens array 204. The PBS prism array 205 includes a plurality of PBS prisms arranged in an array. The PBS prism array 205 splits the light from the light source 201 into two differently polarized types of light. Of the individual PBS prisms 205a and 205b, those which let out S-polarized light as described later have half-wave plates 206 disposed immediately behind them.
A superimposing lens 207 is disposed behind the PBS prism array 205. The images of the individual lens cells 203a of the first lens array 203 are, by the second lens array 204 and the superimposing lens 207, superimposed on one another in the vicinity of the focal point of the superimposing lens 207. The display panel 209 is disposed at the focal point of the superimposing lens 207. The display panel 209 is illuminated in a telecentric fashion by a condenser lens 208 disposed immediately in front of it. The first lens array 203, the second lens array 204, and the superimposing lens 207 mentioned above together constitute an optical integrator system.
The light emitted from the light source 201 is reflected from the reflector 202, and is thereby formed into a substantially parallel beam and passed through the first lens array 203 and the second lens array 204, so that the light exiting from the individual lens cells 204a of the second lens array 204 enters corresponding ones of the PBS prisms 205a of the PBS prism array 205. Here, P-polarized light, indicated by solid lines P, is transmitted straight through the PBS prisms 205a. On the other hand, S-polarized light, indicated by broken lines S, is reflected inside the PBS prisms 205a so as to be directed to the contiguous PBS prisms 205b, and is then reflected again inside the PBS prisms 205b so as to exit therefrom, still as S-polarized light.
The S-polarized light exiting from the PBS prisms 205b is then transmitted through the half-wave plates 206 disposed immediately behind the PBS prisms 205b and is thereby converted into P-polarized light. That is, a portion of the light from the light source 201 has its polarization converted first by the PBS prisms 205b of the PBS prism array 205 and then by the half-wave plates 206, and eventually comes out as uniformly P-polarized light. This arrangement constitutes a polarization conversion device. Here, the type of light into which the light from the light source 201 is converted does not necessarily have to be P-polarized light, but can be of other polarizations. The arrangement described thus far, starting with the light source 201 and ending immediately in front of the display panel 209, constitutes an optical illumination apparatus.
The light thus converted into uniformly P-polarized light is then directed through the superimposing lens 207 to the display panel 209. The display panel 209 modulates, pixel by pixel, the light it is illuminated with according to the display data fed thereto, and emits the modulated light. The light thus emitted then enters an optical projection system 210. The display data presented on the display panel 209 is projected, as an image, onto a screen (not shown) through this optical projection system 210. Reference numeral 210a represents an aperture stop disposed in the optical projection system 210.
In the conventional optical illumination apparatus constructed as shown in FIG. 10, polarization conversion is performed immediately behind the light source 101. Therefore, the light emitted from the light source 101 and then reflected from the reflector 102 has its beam diameter enlarged to about twice its original beam diameter as a result of the polarization conversion. This diminishes the f-number of the illumination light Ia that strikes the display panel 109 and thus diminishes the f-number of the projection light Ea that emanates from the display panel 109, making the burden on the optical projection system 110 heavier.
On the other hand, in the conventional optical illumination apparatus constructed as shown in FIG. 11, the light emitted from the light source 201 and then reflected from the reflector 202 experiences no enlargement of its beam diameter. Therefore, no diminishing occurs in the f-number of the illumination light Ib that strikes the display panel 209 nor in the f-number of the projection light Eb that emanates from the display panel 209. Thus, no extra burden is placed on the optical projection system 210. However, the light from the light source 201 is not converted into uniformly polarized light until it has passed through the second lens array 204. Therefore, in this optical illumination apparatus, no space is available for inserting a polarization-dependent color switching device such as those used in the embodiments of the present invention to be described later. That is, this optical illumination apparatus does not permit a so-called color sequential illumination method using such a color switching device.


The present invention relates to a system and method for the treatment of disorders of the vasculature. More specifically, a system and method for treatment of abdominal aortic aneurysm and the like, which is a condition manifested by expansion and weakening of the aorta below the diaphragm. Such conditions require intervention due to the severity of the sequelae, which frequently is death. Prior methods of treating aortic aneurysm have consisted of invasive surgical methods with graft placement within the aorta as a reinforcing member of the artery. However, such a procedure requires a surgical cut down to access the vessel, which in turn can result in a catastrophic rupture of the aneurysm due to the decreased external pressure from the organs and tissues surrounding the aorta, which are moved during the procedure to gain access to the vessel. Accordingly, surgical procedures have a high mortality rate due to the possibility of the rupture discussed above in addition to other factors. Other factors can include poor physical condition of the patient due to blood loss, anuria, and low blood pressure associated with the aortic abdominal aneurysm. An example of a surgical procedure is described in a book entitled Surgical Treatment of Aortic Aneurysms by Denton A. Cooley, M.D., published in 1986 by W.B. Saunders Company.
Due to the inherent risks and complexities of surgical procedures, various attempts have been made in the development of alternative methods for deployment of grafts within aortic aneurysms. One such method is the non-invasive technique of percutaneous delivery by a catheter-based system. Such a method is described in Lawrence, Jr. et al. in “Percutaneous endovascular graft: experimental evaluation”, Radiology (May 1987). Lawrence described therein the use of a Gianturco stent as disclosed in U.S. Pat. No. 4,580,568. The stent is used to position a Dacron fabric graft within the vessel. The Dacron graft is compressed within the catheter and then deployed within the vessel to be treated. A similar procedure has also been described by Mirich et al. in “Percutaneously placed endovascular grafts for aortic aneurysms: feasibility study,” Radiology (March 1989). Mirich describes therein a self-expanding metallic structure covered by a nylon fabric, with said structure being anchored by barbs at the proximal and distal ends.
One of the primary deficiencies of the existing percutaneous devices and methods has been that the grafts and the delivery catheters used to deliver the grafts are relatively large in profile, often up to 24 French and greater, and stiff in bending. The large profile and bending stiffness makes delivery through the irregular and tortuous arteries of diseased vessels difficult and risky. In particular, the iliac arteries are often too narrow or irregular for the passage of a percutaneous device. Because of this, non-invasive percutaneous graft delivery for treatment of aortic aneurysm is not available to many patients who would benefit from it.
Another contraindication for current percutaneous grafting methods and devices is a vessel treatment site with high neck angulation which precludes a proper fit between the graft and the vessel wall. An improper fit or seal between the graft and the vessel wall can result in leaks or areas of high stress imposed upon the diseased vessel which lead to reduced graft efficacy and possibly rupture of the aneurysm.
While the above methods have shown some promise with regard to treating abdominal aortic aneurysms with non-invasive methods, there remains a need for an endovascular graft system which can be deployed percutaneously in a small diameter flexible catheter system. In addition, there is a need for a graft which conforms more closely to the contours of an aortic aneurysm which are often quite irregular and angulated and vary from patient to patient. The present invention satisfies these and other needs.


Roku, Inc., of Saratoga, Calif., the assignee of the present invention, currently offers a streaming media platform for connection to a television. In particular, the streaming media platform utilizes a cable (i.e., a High Definition Multimedia Interface or HDMI cable) to connect to external ports of a television. The streaming media platform uses a wireless connection to access the internet. Consequently, streamed media from the internet is wirelessly collected by the streaming media platform and is applied to the cable for display on a television.
There are commercially available televisions with resident internet access circuits. These internet access circuits may access the internet through a wireless connection or a wired connection, such as an Ethernet cable connection. Many purchasers are reluctant to purchase a television with a built-in internet access circuit because such purchasers do not want to be committed to a certain internet connection interface.


1. Field of the Invention
The invention relates to the field of optical fibers for wavelength division multiplex transmission networks.
2. Description of the Prior Art
Increasing information bit rates on this type of network impose compensation of chromatic dispersion and dispersion slope over bands of the spectrum other than the C band. The S band extends approximately from 1 460 nm to 1 530 nm. The C band extends approximately from 1 530 nm to 1 565 nm. The L band extends approximately from 1 565 nm to 1 625 nm. The U band extends approximately from 1 625 nm to 1 675 nm. The most widely used band is the C band. The invention relates to fibers with chromatic dispersion compensation in the S band.
In the prior art, it is known to combine certain types of dispersion shifted optical fibers reducing crossed non-linear effects, known as non-zero dispersion shifted fiber (NZ-DSF), with dispersion compensating fiber (DCF), thereby achieving a transmission line with no dispersion over a wide spectral range.
The patent application EP 1219986 discloses using an optical fiber with chromatic dispersion compensation in the S band, but the examples described with two or three slices either have a ratio between the attenuation at 1 520 nm and at 1 500 nm greater than two or a chromatic dispersion to dispersion slope ratio that renders them unsuited to the object of the invention.
The invention proposes a chromatic dispersion compensating optical fiber which, either because of profiles with at least four slices or because of profiles with three slices having structures corresponding to particular ranges of index and radius, provides effective compensation in the S band of the chromatic dispersion of a certain range of line optical fibers, combined with attenuations at 1 500 nm and at 1 520 nm that are comparable. A particularly advantageous aspect is the very deeply buried nature of the index of the first buried slice (or of the only buried slice if there is only one) relative to the index of the central slice.


In superconducting magnets, variations in magnetic fields and temperature are common occurrences which often cause conduction faults in superconducting filaments. To compensate for such conducting faults, the magnetic windings are usually formed of wires in which the superconducting filaments are encased in a metal, such as silver, copper or aluminum, which is normally conductive across a wide range of temperatures, including superconducting temperatures. The metal electrically stabilizes the wire by shunting any portion of the filament(s) which has become non-superconducting. Furthermore, the encasing metal has good thermal conductivity, tending to transfer heat away from hot spots in the windings. Nevertheless, events, such as flux jumps, wire motion or eddy currents, in the superconducting filaments or encasing metal produce heat which may lead to a precipitous normalization of superconductive windings. Such temperature excursions occur during periods measured in microseconds, such short periods being insufficient for dissipation of the heat to the coolant, e.g., liquid helium.
To reduce the probability of normalizing temperature excursions, U.S. Pat. No. 4,171,464 proposes that particles or fibers of gadolinium oxide or gadolinium-aluminum oxide be incorporated in the metal, e.g., copper, that encases the superconducting filaments. These materials have high heat capacities at superconducting temperatures, e.g., below about 5.degree. K., and thus tend to absorb substantial amounts of locally produced heat. Furthermore, these materials undergo antiferromagnetic transitions within the superconducting temperature range, and when a decrease in the magnetic field occurs as a result of a conduction fault, the specific heat of the material increases, enhancing the adiabatic stabilization.
However, adiabatic thermal stabilization through adiabatic demagnetization by compositions, such as the gadolinium and gadolinium-aluminum oxides which undergo antiferromagnetic transitions, is only realized if the effective magnetic field experienced by the material decreases. Thus, the material is less efficient in preventing precipitous normalizations in circumstances where a localized normalization of the superconducting filaments occurs but does not produce an immediate change in the magnetic fields to which the thermal stabilizer is subjected.
Furthermore, because the magnetically affected contributions to heat capacity of materials, such as gadolinium oxides, are a substantial portion of the total heat capacity and because these components of their total heat capacity decrease with increasing magnetic field, these materials are less useful for thermal stabilization in superconducting applications where very intense magnetic fields are produced. As noted in the above-mentioned '464 patent, Gd.sub.2 O.sub.3 has substantially less heat capacity in a 2.4 Tesla (Tesla=10,000 Gauss) field than in a 0 Tesla field. Many present day superconducting magnet applications require substantially higher magnetic fields; for example, at the present time, superconductng magnets for fusion applications may produce magnetic fields in the range of 15 Tesla. At such magnetic field intensities, the heat capacities of materials, such as Gd.sub.2 O.sub.3, having large magnetic field-affected components of heat capacity, will be severely depressed.
There is a need for materials for use in superconducting applications which have high heat capacities and which are substantially unaffected by the magnetic field.


The present invention relates to an automatic sheet cutting apparatus which cuts off a sheet like a knit or a woven fabric into a predetermined shape. More particularly, the invention relates to a vacuum air leakage preventive device combined with an automatic sheet cutting apparatus so that evacuated air can be prevented from leaking through a clearance between a bottom surface of one of any brush-mounting bases aligned in parallel with a pair of endless chains and a top surface of the main body of the automatic sheet cutting apparatus.
Any of those conventional chain-driven automatic sheet cutting apparatuses is provided with a number of brush-mounting bases which are aligned on a top surface of a sheet cutting table in parallel with a pair of endless chains installed on both sides of the main body of the automatic sheet cutting apparatus by way of being suspended on them. These brush-mounting bases sequentially move themselves relative to the rotation of a pair of endless chains. In the same way, a number of brushes secured on respective bases move themselves in conjunction with a cuttable sheet. Next, a control system stops the rotation of these endless chains at a predetermined position, and then activates a suction unit below the main body of the automatic sheet cutting apparatus to position the objective sheet on those brushes via a number brushes and those brush-mounting bases before permitting a cutting unit to cut the sheet on a cutting table surface into a predetermined shape by moving the cutting unit to the cutting position.
On the other hand, since there is substantial space between a pair of endless chains on both sides of the automatic sheet cutting apparatus, a supporting member is disposed on the main body of the automatic sheet cutting apparatus so that a number of brush-mounting bases aligned in parallel with and being suspended on these endless chains can slide themselves on the supporting member. This in turn results in an increased resistance against the sliding movement of those brush-mounting bases, and therefore, the apparatus needs to provide such a drive motor having substantial drive capacity.
Therefore, in order to solve this problem, any conventional automatic sheet cutting apparatus is provided with sliding members or rollers below respective brush-mounting bases to shift those brush-mounting bases by causing those sliding members or rollers to slide or roll themselves on the supporting member.
Nevertheless, when these sliding members or rollers installed below those brush-mounting bases on the supporting member of the automatic sheet cutting apparatus slide or roll themselves on the supporting member, a narrow clearance is generated between the bottom surface of those brush-mounting bases and the supporting member. In consequence, when operating a suction unit to pneumatically evacuate a cuttable sheet on those brushes via those brush-mounting bases and brushes, evacuated air leaks out of this clearance, thus resulting in a lowered efficiency.
Therefore, an object of the invention is to fully solve those technical problems inherent in any of those conventional automatic sheet cutting apparatuses by providing a novel system for preventing evacuated air from leaking out of a clearance between the bottom surface of each brush-mounting base aligned on a pair of endless chains and the top surface of the main body of the automatic sheet cutting apparatus.


Certain presentations and graphs require printing on a printable media, such as a paper sheet, of a dimension that is most beneficially presented in the form of a strip, for example, presentation charts used in project management. Project management is the planning and control of many activities that must be coordinated to achieve specific goals leading to the completion of an overall given objective. The project management process frequently uses a set of tools which incorporate charts and reports to detail the project for communication within the project team and with others.
One form of project management chart is referred to as a work breakdown structure (WBS) chart. A WBS chart is an organizational diagram type of chart depicting work packages comprising all of the principal elements of a project. Another form of project management chart, used for communication with the project team and with others, is a precedent network (Network) chart, sometimes erroneously referred to as a PERT chart. The Network chart displays activities required to produce the work packages depicted in the WBS chart and shows the relationships between the activities, i.e. the precedents and dependencies between the activities as they flow towards completion of a project.
For practical project management purposes, the WBS and Network charts are usually more than one standard sized page in width. To present either chart may require many standard sized pages to be joined one to the other. As the project evolves, the project management process results in the updating, modifying, and reproducing the project charts as a consequence of project progress. Thus, the WBS and network charts will change during the course of the project, consequently requiring the WBS and network charts to be produced frequently during the course of the project. To allow the charts to be printed on standard sized paper using conventional computer printers or photocopied onto standard sized paper, requires the joining of standard sized pages together to form a completed WBS or Network chart. Joining these pages is a time consuming process and usually requires input from the project manager to lay out the pages in a proper sequence prior to cutting and pasting them together to form the chart. Each time revised charts are produced during the life of a project, several copies are required each for key team members. The page assembly process to produce the charts is a frustrating task and often results in sloppy presentations even though the computer-generated data or the images printed or photocopied on each of the individual pages may be perfect.


Tertiary treatment of municipal sewage is a common wastewater application for ultrafiltration and microfiltration membranes; however, such systems need to be capable of operating on high suspended solids feed waters while having a long life with a minimum of chemical cleanings. Suspended solids that need to be removed may be materials that cause turbidity, such as bacteria, cysts and oocysts, viruses, colloidal material, such as iron oxides, clay, silt, sand and other insoluble impurities. Municipal sewage secondary treatment effluent typically has turbidity levels of 5 to 10 NTU with a suspended solids count of 10 to 20 parts per million (ppm). For membrane technology to be economically competitive in a tertiary treatment process, it should operate at sustained permeate flux rates of 15 to 30 gallons per square foot per day (gfd) with minimal energy consumption, while requiring chemical cleaning at a frequency of not more than once per month.
Perhaps the biggest dilemma facing ultrafiltration and microfiltration membrane technology is fouling, where suspended solids and natural organic matter are adsorbed onto the membrane surface and result in a decrease in permeate flux. Decreased permeate flux rates result in higher overall capital and operating costs due to the lower output over a given period of time. The development of new membrane technologies has focused on reducing or eliminating the adverse affects of membrane fouling. A membrane element or cartridge that can produce high flux rates while minimizing fouling can have an extreme economical advantage over competing technologies.
Historically, such difficult applications as treating feed solutions high in organic and suspended solids have employed spiral wound, hollow fiber, capillary, or tubular element designs in a multitude of configurations. The most common of configurations is a submerged membrane system where the membranes, whether it be spiral wound or hollow fiber, are placed vertically in an open tank and filled with a feed solution to be filtered.
Very generally, a spiral wound membrane cartridge contains a permeate carrier sheet, a membrane filter sheet that is adhesively bonded to the permeate carrier sheet (usually to both surfaces thereof to create an envelope about it), and a feed spacer sheet which separates two facing membrane filter layer sheets. Microfiltration (MF) and ultrafiltration (UF) membranes are typically formed of either polyethersulfone (PES), polysulfone (PSF), polyvinylidene fluoride (PVDF), or polyacrylonitrile (PAN) because these polymers are generally recognized in the industry to make membranes having high flux rates, good chemical resistance and good physical durability, which can be produced using conventional casting techniques. Other polymers such as polypropylene, polyethylene, and chlorinated polyethylene may also be used to construct UF and MF membranes. Spiral wound membrane cartridges exhibit good fouling resistance and offer economically attractive filtration with greater mechanical durability.
A traditional submerged membrane system is shown in FIG. 6 of WO 00/78436 patent application (28 Dec. 2000) wherein a spirally wound membrane element is immersed in a tank that is filled with a body of water to be filtered and air is bubbled up through the membrane for the purpose of maintaining a clean membrane surface. The required transmembrane pressure (TMP) is supplied by a pump that creates a vacuum in addition to any contribution from the static head. Alternatively, static liquid heads alone have been used to generate feed pressures for submerged filtration, see U.S. Pat. No. 5,916,441. These systems will typically also employ support frames and manifolds. Materials of construction are typically limited to 316 stainless steel for these type of systems, which is a significant capital expenditure. The use of 316 stainless steel also limits the amount of exposure to certain corrosive water sources, such as cleaning solutions and aggressive feedwaters such as seawater.
Factors which contribute to membrane fouling include water chemistry, suspended solids concentration (TSS), membrane chemistry and transmembrane pressure (TMP), are used to combat same. Membrane chemistries vary between polysulfone (PSF), polyethersulfone (PES), and polyvinylidene fluoride (PVDF); however, all are generally similar in their fouling tendencies. The more hydrophilic a membrane chemistry is, the more resistant it is to fouling, as fouling constituents are generally hydrophobic.
Membrane fouling typically occurs through two different mechanisms; pore impregnation and cake-layer formation. Pore impregnation occurs when organic and suspended solids penetrate and impregnate the pores of a membrane, thus narrowing the effective diameter of the pores and increasing the required net drive pressure for permeate production. Cake-layer formation involves large colloidal compounds and suspended solids accumulating on the membrane surface and forming a discrete layer of organic and suspended solids. Both fouling mechanisms result in decreased permeate flux.
Common methods to offset the effects of fouling for submerged membrane systems include air bubbling, backwashing, and chemical cleaning. Air bubbling, whether it be for a spiral wound or hollow fiber membrane, is quite effective at removing particulate matter from the membrane surface; however, it is an energy intensive process that often comprises 50% or more of the total energy costs associated with a submerged membrane system. The economical advantages of a membrane system that can eliminate or greatly reduce the use of air bubbling without increasing chemical cleaning frequency are obvious.
When the effects of fouling become irreversible, membrane cartridges require extensive cleaning with a variety of chemical cleaners. Existing submerged membrane systems often rely on extensive static soaking with an oxidant-based, caustic-based, and/or acid-based cleaner. Air bubbling is discouraged during cleaning and is often discontinued during the cleaning process so as to avoid excessive foaming and/or release of harmful vapors to the atmosphere. However, static cleaning has been found to be much less effective than dynamic cleaning wherein the added shear force enhances the removal of organic and suspended material from membrane surfaces.
Another problem associated with submerged membrane systems is the accumulation of solids in the process tank and the inefficient removal thereof. With submerged membrane systems, the suspended solids level inside the tank increases over time, due to accumulation, until a steady state value is reached. This steady state suspended solids level is directly proportional to the recovery of which the system operates at. For example, a system that operates at 90% recovery will have a steady state suspended solids value about ten times greater than that of the influent level. Since membrane fouling is directly proportional to suspended solids concentration, it is obvious that membrane fouling will be greater when the suspended solids level has reached its steady state concentration value; however, it is highly undesirable to lower the system percentage recovery for the sake of reducing fouling as such would drastically lower the overall efficiency of the system, potentially rendering it impractical and economically unattractive. Moreover, after every backwash, solids removed from the membrane surface are mixed directly back into the bulk tank solution, further complicating the solids build-up problem. Because large, submerged membrane systems utilize process tanks having very large holding volumes, it is impractical to drain said tanks on a frequent basis in order to purge the accumulated solids from the system.
With the foregoing in mind, work on improvements was undertaken.


Wireless scanners, or readers, may detect the presence of tags. If the scanners fail, replacing the scanners may be cumbersome, resulting in some tags going undetected.


Because silicon nitride sintered products are excellent in various properties such as mechanical strength, heat resistance, etc., they are used as high temperature structural materials, such as for parts of gas turbines. However, on the other hand, silicon nitride has a poor sinterability because of having a highly covalent bonding nature, and, consequently, it is difficult to obtain sintered products having a high density and high strength, employing silicon nitride per se. Therefore, in the case of sintering silicon nitride, sintering aids including MgO, Al.sub.2 O.sub.3, oxide of rare earth elements, etc., have been used hitherto. However, sintered products using MgO as a sintering aid have inferior oxidation resistance because MgSiO.sub.3, etc., are formed in the oxidizing atmosphere. In sintered products using Y.sub.2 O.sub.3 as a sintering aid, the oxidation resistance deteriorates extremely if YSiO.sub.2 N and Si.sub.3 Y.sub.2 O.sub.3 N.sub.4 are formed as the second phase (the meaning of which is hereinafter explained) as opposed to forming Si.sub.2 ON.sub.2, Y.sub.2 Si.sub.2 O.sub.7, or Y.sub.5 Si.sub.3 O.sub.12 N. Formation of the second phase is affected by the amount of Si.sub.3 N.sub.4, SiO.sub.2, or Y.sub.2 O.sub.3, the kind and the amount of other sintering aids, the sintering atmosphere, etc., and it is difficult to correctly control these factors. In the case of using CeO.sub.2 as a sintering aid, the second phase composition having good oxidation resistance is not formed in an Si.sub.3 N.sub.4 -CeO.sub.2 system, because CeO.sub.2 is reduced to Ce.sub.2 O.sub.3 during sintering and the produced oxygen reacts with Si.sub.3 N.sub.4 to form SiO.sub.2. In the case of using other oxides of rare earth elements as sintering aids, compositions having improved oxidation resistance have not yet been obtained.


The primary source for oxygen for a grill comes from below the burner. Conventional grills have vents located near the bottom of the grill, below the burner, to allow for air flow which supplies the necessary oxygen. However, if the airflow through these vents is at too high a velocity, the flame at the burner can be blown out. This can cause conventional grills to be virtually useless. in high wind environments.
Additionally, other areas of high velocity airflow can also disrupt the burner operation. One such area is the venturi assembly. Conventional grills have a venturi tube for mixing propane and air which is generally located outside of the grill tub. High wind conditions can result in this mixture being diluted too much, resulting in the burner flame going out. Additionally, high velocity airflow in the area directly above the burner can disrupt the burner operation. This can occur either when the grill hood is open, allowing the wind to access the top of the burner through the heat diffusing material, which typically consists of rocks or ceramic bricketts. Wind can also affect burner operation through vents in the grill hood when the hood is closed. In any of these cases, the high wind conditions can cause the flame at the burner to go out, and thus the grill must be re-lit, if possible, in order to continue operation.
Based on the foregoing, there is a need for a grill which overcomes these problems and protects the flame at the burner from high velocity airflow.


Electromagnetic devices such as motors, generators, magnets, and solenoids, use stacked laminations made from silicon-iron (Si--Fe) for example for providing efficient flux paths for the operation thereof. The laminations must be suitable stacked together either using mechanical fasteners or by welding. Exemplary mechanical fasteners include straps, keys, and rivets suitable positioned in the laminations for holding them together. However, the laminations are typically pre-machined for accepting the mechanical fasteners such as by being punched or providing apertures therefor, which premachining induces stress in the laminations. A pulsed annealing operation is therefore typically required for reducing the residual stresses for minimizing magnetic core losses therefrom. The location of the fasteners themselves may also lead to inefficient flux paths within the laminations decreasing the efficiency of the device.
Welding, on the other hand, necessarily heats the laminations which adversely affects the magnetic properties thereof and may distort the laminations. This may require a pulsed-heat treatment to reclaim the lost magnetic properties and remove the distortions.
Conventional TIG welding is one process known to provide excessive heat into the laminations necessarily requiring the pulsed-heat treatment thereof. Excessive heat input into the laminations may also cause physical distortion thereof which must be suitably corrected in order to obtain a satisfactory product.
It is also known to use a conventional CO.sub.2 laser for welding stacked laminations for reducing the heat input thereto and reducing both thermal distortion thereof and the degradation of magnetic properties therein. However, CO.sub.2 lasers when conventionally used for welding are typically operated as continuous-wave lasers and therefore continuously input heat into the welded member although such heat input is significantly less than that from conventional TIG welding. Continuously applied welding heat and the resulting continuous, substantially uniform weld bead may still degrade the magnetic properties of the laminations from excessive heat.


As taught in U.S. Pat. No. 3,489,687 (Inamorato et al.), U.S. Pat. No. 4,276,205 (Ferry), and U.S. Pat. No. 4,659,565 (Smith et al.), it is known that mixed tert-amine oxides containing alkyl groups of different chain lengths can be used in conjunction with other materials, such as other surfactants, detergent builders, and/or other additives, to prepare liquid or solid detergents.
The mixed tert-amine oxides which have been synthesized by conventional techniques, i.e., the typical aqueous solutions of mixed tert-amine oxides, present no particular problems in the preparation of liquid detergents in which their water content is not a liability. However, they have to be dried in order to be used in the preparation of solid detergents.
The technique used by Inamorato et al. to dry their aqueous tert-amine oxides is to mix them with sufficient amounts of hydratable inorganic salts, such as sodium sulfate or sodium tripolyphosphate, to react with substantially all of the water in the solution. Using this technique, they form a friable amine oxide/hydrated salt mixture which they can granulate to obtain a free-flowing detergent composition.
When Ferry uses tert-amine oxides to prepare solid detergents, he spray-dries the aqueous solutions--a technique that is effective in removing the water but has the unfortunate side-effect of subjecting the amine oxides to temperatures at which they are apt to decompose and form amines that are corrosive to the skin.


Semiconductor devices are becoming smaller and more dense with the evolution of new technology. However, increases in circuit density produce a corresponding increase in overall chip failure rates at a time when chip failure rates must decrease to remain competitive. Chip manufacturers are therefore challenged to improve the quality of their products by identifying and eliminating defects which produce defective chips known as fails. Whereas significant improvements are being made to eliminate systematic defects by reducing process variability. Process improvements alone are not sufficient to eliminate all the random defects which effect both yield and reliability. Historically, screening techniques have been employed to improve product failure rates to acceptable levels by culling out many of these random defects.
Single chip or multi-chip packaging strategies require the ability to join or replace individual chips from an assembled chip module. This should of course be done without altering the integrity of the remaining chips or capacitors or other electronic components. Chip changing is also required for yield management, upgrade capability, and engineering changes, to name a few. Chip replacement typically involves three distinct steps: chip removal, chip site solder dress, and new chip rejoin. Different tools and processes are used in the chip removal or chip join process.
U.S. Pat. No. 3,283,124 (Kawecki), discloses a selective heating apparatus where energy from an infrared source is focused through the use of a special focusing means.
U.S. Pat. No. 4,160,893 (Meyen et al.) discloses an individual chip joining machine, where an IR lamp is used to heat the upper surface of a chip through a flat quartz plate.
U.S. Pat. No. 4,278,867 (Tan) discloses a system for chip joining by short wavelength radiation. Tan uses a laser to heat the upper or back-side surface of a chip during the process.
IBM Technical Disclosure Bulletin, "Luminous Dual Reflection Lamp" Vol. 20, No. 6, Pages 2141-2142 (November 1977), discloses a lighting system for uniformly scattering light without projecting either characteristic central hot spots or concentrated filament images. This is achieved by using a flat clear quartz plate, having a reflecting convex portion and a concave reflector.
Puttlitz, et al., "Replacing Flip Chips on MLC Multichip Modules Using Focused Infrared (IR): The Basics", ISHM '92 Proceedings, Pages 384-390 (October 1992), discloses a means of locally heating a target chip, site dressing the chip site, and placing and reflowing a replacement chip. This is done by using an infrared (IR) quartz-halogen lamp within a metal reflector housing. The IR lamp is typically located at or near the parabolic reflector focal point so that its energy can be directed and focused onto the backside of the target chip. Heating can, however, be confined to the target chip by introducing a substrate shield that prevents irradiating the surrounding MCM surface and attachments. This assures that only the target chip is irradiated (i.e., heated) when the IR lamp is energized.