The aim of exploration seismology is to obtain an image of the subsurface by probing it with seismic waves at various locations. These waves are generally generated by using airguns in marine, and vibroseis or dynamite in land. They propagate downwards through the subsurface, and are reflected at interfaces between geological layers or refracted within layers. Parts of these waves subsequently propagate upwards to the surface, where they are detected and recorded.
In exploration seismology, although the time coordinate is regularly sampled, spatial coordinates are typically irregularly sampled due to the presence of obstacles in land and strong currents in marine. But even for example receivers placed within a marine survey cable or streamer may not be always equidistant. Hence, the inline sampling can be quite irregular.
The regularization of seismic data is very important especially in time-lapse survey matching, multiple suppression and imaging. If the irregular nature of the sampling grid is ignored or handled poorly, notable errors are introduced the severity of which may be further amplified at later stages of the seismic processing chain. The problem of signal reconstruction from uniformly spaced data has been investigated in depth. The Whittaker-Kotel'nikov-Shannon sampling theorem states that any signal f(x) can be reconstructed from its uniformly spaced samples if the sampling interval is less than half the period of the highest frequency component in that signal. Thus if f(x) is bandlimited to the wavenumber s/2, which is known as the Nyquist wavenumber, then the sampling theorem provides the following formula to interpolate any function value from uniformly spaced values f(m/s):
                              f                                (            x            )                          =                              ∑                          m              =                              -                ∞                                      ∞                                                        f                                            (                                  m                  /                  σ                                )                                                  sin                                                                                c                                            (                                                      σ                                                                                x                                    -                  m                                )                                                                        [        1        ]            where sinc(x)=sin(πx)/πx. Thus, when the sampling rate is sufficient and there is no aliasing, the sampling theorem provides a way to reconstruct the signal “exactly” from its uniformly spaced samples. To satisfy requirements of the sampling theorem, the signal should be sampled at a rate greater than twice the Nyquist rate, i.e., s. The seismic signal may be given by:
                                          f                                      (              x              )                                ≈                                    f              L                                                  (              x              )                                      =                  σ                                              ∑                              m                =                0                                            L                -                1                                                                Δ                                                                                x                m                                                          f                                                  (                                      x                    m                                    )                                                          sin                                                                                c                                                  (                                      σ                                                              (                                              x                        -                                                  x                          m                                                                    )                                                        )                                                                                [        2        ]            where Δxm is the Jacobian weight, i.e., Δxm=xm+1−xm and f(xm) the value of the seismic data at irregular offset xm. It is important to note that, when Δxm=1/σ the sinc interpolator of eq. [2] is exact since
                              f                                (            x            )                          =                              ∑                          m              =                              -                ∞                                      ∞                                                        f                                            (                                  m                  /                  σ                                )                                                  sin                                                                                c                                            (                                  σ                                                        (                                          x                      -                      τ                                        )                                                  )                                                                        [        3        ]            by Whittaker-Kotel'nikov-Shannon theorem. On the other hand, when Δxm is not equal 1/σ, the sinc interpolator provides only a crude approximation to the continuous signal.
For such cases, it has been found that a better approach is to invert equation [1] for the desired uniformly spaced signal values f(m/σ). This inversion when written in matrix notation yields
                    h        ≡                                                                                        f                                                        (                                          x                      1                                        )                                                                                f                                                        (                                          x                      2                                        )                                                                                M                                                                                f                                                        (                                          x                      L                                        )                                                                                                ≈                                                                                                              s                    11                                                                                s                    11                                                                    Λ                                                                      s                                          1                                                                                L                                                                                s                    21                                                                                s                    11                                                                    Λ                                                                      s                                          2                                                                                L                                                                                M                                                  M                                                  O                                                  M                                                                                s                    11                                                                                s                    11                                                                    Λ                                                                      s                    LL                                                                                            ·                                                                                                      f                                                              (                      0                      )                                                                                f                                                              (                                              1                        /                        σ                                            )                                                                                f                                                              (                                                                        (                                                      L                            -                            1                                                    )                                                /                        σ                                            )                                                                                                          ≡        Sg                            [        4        ]            where σ/2 is the bandwidth of the signal f(x) and S is the sinc matrix with entries sij=sinc(σ(xi−j/σ). If the matrix S is well conditioned than the seismic data at regular offsets can be computed by standard matrix inversion:g=S−1h  [5]Otherwise, a least squares minimum norm inversion can be used:g=(STW1S+W2)−1STW1h  [6]where W1 is usually chosen as a diagonal matrix whose mth diagonal entry is the Jacobian weight Δxm=xm+1−xm and W2 is usually chosen as a small multiple of identity matrix, i.e., W2=ε2I.
This necessitates the use of robust and efficient techniques for seismic data regularization.
An interpolator in accordance with equation [6] has been described in: Yen J. L., 1956, On nonuniform sampling of bandwidth-limited signals, IRE Trans. Circuit Theory, CT-3, 251-257 (1956). It is therefore sometimes referred to as Yen's Interpolator of Type 1.
Many interpolators used in seismics are variations of the Yen's interpolator for example those described in: Duijndam, A. J. W., Schonewille, M. A., Hindriks, C. O. H., Irregular and sparse sampling in exploration seismology (chapter of L. Zhang: Nonuniform sampling: theory and practice, Kluwer Academic/Plenum Publishers, New York, USA (2001)). The regularization in Duijndam is formulated as a spectral domain problem. There it is proposes to estimate the spectrum of the signal by using non-uniform Fourier transform of the irregular samples, and then reconstruct the regular samples by using inverse discrete Fourier transformation. It can be shown that, this regularization technique is exactly equivalent to Yen's Interpolator of Type 1.
A variant of this method is described in: Zwartjes, P. M. and M. D. Sacchi, 2004, Fourier reconstruction of non-uniformly sampled, aliased data: 74th Ann. Internat. Mtg.: Soc. of Expl. Geophys., 1997-2000. However in Zwartjes there is proposed least squares inversion of the Fourier transformation instead of using an inverse discrete Fourier transform. To this purposes a cost function is defined, which also involves a non-quadratic penalty term to obtain a parsimonious model.
Another example is: Hale, I. D., 1980, Resampling irregularly sampled data, Stanford Exploration Project, SEP-25, 39-58. Hale's method is based on the more general version of the Yen's Interpolator, where a space limited signal assumption is not used. In that case, the uniform samples f(m/σ) can still be computed by solving a matrix equation similar to [6]. What Hale suggests is to replace the entries in the inverse matrix by their locally computed approximations.
The interpolators based on Yen's 1st theorem usually provide satisfactory results on non-aliased signals with little high-wavenumber content. However their performance degrades significantly when the interpolated signal has a substantial amount of high wavenumber spectral content. Another shortcoming of the interpolators based on Yen's 1st theorem is that in order to solve [4], at least as many irregular sampling positions as regular sampling positions are required. Hence, if some seismic traces are dropped out, traces which reside at further locations must be used to solve the system of equations given by [4]. Usually this degrades the accuracy of the interpolated sample values.
Further, although Yen's 1st interpolator is exact for infinite length signals, it is an approximation when only a finite extent of the signal is available for interpolation.
Given the problems of the existing interpolators it remains an object to find improved interpolates capable of interpolating data received by receivers at irregular locations to regulars sampling locations.


1. Field of the Invention
The present invention relates an antenna, and, more particularly, to a triple-band antenna for different frequency bands, which is designed for an increased low frequency bandwidth and different intermediate frequency bandwidths.
2. Description of the Related Art
With the rapid growth of wireless communication technologies, standard signal frequency antennas are now insufficient, and so multiple frequency antennas have become the technology of choice. A multiple frequency antenna is usually used in a portable electronic device that supports wireless communication functions, such as a notebook, a mobile phone or a PDA. Since these electronic devices are all very thin and light, it is necessary to have small-volume multiple frequency antennas. However, usually when the antenna has a smaller volume, its reception efficiency is also reduced, and multiple frequency antennas may have narrow frequency bandwidths at different frequency locations. Therefore, the design needs to compromise between volume and reception efficiency. Moreover, the standard multiple frequency antenna with an intermediate frequency band reception ability may also fail to have a broadband response due to the design.
It is therefore desirable to provide a triple-band antenna to mitigate and/or obviate the aforementioned problems.


Ambulances are able to carry only a very small number of patients (generally only one or two), making it extremely complex to transport all the victims or patients that have treatment or evacuation needs when a mass casualty event or disaster occurs. Currently, when such an event occurs, many ambulances are called to transport the victims, and, given the limited number of ambulances generally available within a given geographic area, the total number of patients that can be transported is also greatly limited. Furthermore, with so many victims needing transportation from one mass casualty event, if all conventional ambulances are used for transport, people in other coverage areas might suffer because ambulances are not available to handle other emergencies.
A similar problem is encountered when an evacuation of a large number of patients is required. For example, the ability to relocate the patients from a hospital or a nursing home that may be in the path of an approaching hurricane also would be limited by the availability and number of ambulances available.
Similarly, if there is a need to treat a large number of victims at a given location, the only option available now is to transport the victims to a remote site for treatment, and movement of the large number of victims is similarly impacted by the limited number of ambulances. Alternatively, a tent-like treatment facility might be set up, but the suitability of such a system would depend on the disaster conditions (e.g., a tent would not hold up well during windy conditions; climate extremes might be difficult to control; once patients are stabilized in the tent-like structure, they would still need to be transported to a hospital or other facility for extended care).
Other ambulance-type vehicles, such as those used in the military, use J-type hooks or loop-type straps for holding stretchers, and loading a stretcher onto such a J-hook type holder or loop-type straps requires up to six people to maneuver the stretcher into storage position.
Furthermore, if there is a need to transport a large number of casualties, multiple ambulances or hearses would be needed.


1. Field of the Invention
The present invention generally relates to a system managing method and apparatus and, more particularly, to a system managing method and apparatus using both a managed object interface and a non-managed object interface.
In a system such as an exchange system supporting a plurality of kinds of interfaces including a managed object (MO) interface and a non-managed object (non-MO) interface, it is desired to simplify a process using the MO interface and the non-MO interface. The MO interface includes common management information protocol (CMIP). A TL1 command and a graphical user interface (GUI) are included in the non-MO interface.
2. Description of the Related Art
FIG. 1 is an illustration for explaining a conventional system management model. The system management model shown in FIG. 1 is an open system interconnection (OSI) system which enables interconnection between different computer network systems. In the system management model shown in FIG. 1, communication between a managing system 41 (manager 43) and a managed system 42 is specified. The managed system 42 includes a plurality of managed objects (MOs) 45 and an agent 44 which operates the managed objects 45.
The managing system 41 (manager 43) may correspond to a managing apparatus such as a maintenance terminal apparatus provided with processors and memories. The managed system 42 may correspond to a switching apparatus provided with processors and memories. In the system management model shown in FIG. 1, resources to be managed are abstracted so as to manage the resources as the managed objects. The managed objects include concepts of a managed object class (MO class) and a managed object instance (MO instance). The MO class defines a characteristic of a managed object. The MO class defines attributes, attribute groups, notifications, operations and behavior. The MO instance represents a specific object defined by the MO class.
For example, the above-mentioned CMIP is defined as a protocol for transmission and reception of management commands and notification information of the managed objects 45 between the managing system 41 (manager 43) and the agent 44 of the managed system 42. The CMIP is a protocol for use on an individual managed object basis. A simple network management protocol (SNMP) is well-known as the CMIP. An interface between the manager 43 and the agent 44 is referred to as the MO interface. That is, the MO interface specifies communication between the managing system 41 and the managed objects 45 via the agent 44 such as transmission of managing operation commands from the managing system 41 (manager 43) to the managed objects 45 or transmission of notification from the managed objects 45 to the managing system 41.
Such a specification of communication is known as a common management information service (CMIS). The managing operations according to the CMIS includes, for example, M-GET which is acquisition of an attribute value, M-SET which is setting of an attribute value, M-ACTION which is an operation on the managed object, M-CREATE which is creation of the managed object, M-DELETE which is deletion of a managed object and M-CANCEL-GET which is cancellation of the M-GET. Notification according to the CMIS includes M-ENENT-REPORT which is a notification sent from a managed object.
On the other hand, the TL1 command or the GUI does not handle resources as the managed object. Such an interface is referred to as the non-MO interface. The non-MO interface is used in various systems including a switching system. In the TL1 command, invoked process and parameters for the process are specified.
FIG. 2 is an illustration for explaining another conventional system management model in which both the MO interface and the non-MO interface are used. The management system model shown in FIG. 2 includes a managing system (manager) 51 for the MO interface, a managed system 52, an agent 54, a common processing unit 55 and a managing system (manager) 56 for the non-MO interface.
The managed system 52 is provided with the common processing unit 55 so that a managing operation for both the MO interface managing system 51 and the non-MO interface managing system 52 can be performed. The common processing unit 55 has a structure based on either the MO interface or the non-MO interface.
If the common processing unit 55 has a structure suitable for the MO interface in the above-mentioned system in which both the MO interface and the non-MO interface are supported, the unit of process requested of the common processing unit 55 is the MO class and a full distinguished name (FDN). The FDN is a symbol used for designating the MO instance which belongs to one of the MO classes in the MO interface. That is, the FDN is an identification number of the MO instance managed as a hierarchical structure according to a hierarchical relationship between a plurality of MO classes.
In this case, a function of the common processing unit 55, which function is in accordance with the CMIP command including the MO class name and the FDN, can be correlated to a command sent from the MO interface. However, an appropriate function of the common processing unit 55 cannot be provided in response to a command sent from the non-MO interface since the command does not include the MO class name and the FDN. In such a case, a process is required for relating the non-MO command to a function of the common processing unit 55 that is based on the MO interface. Thus, the agent 54 performs such a process.
On the other hand, if the common processing unit 55 has a structure suitable for the non-MO interface, the function of the common processing unit 55 is constituted by the unit of command handled by the non-MO interface. Thereby, an appropriate function of the common processing unit 55 can be provided in response to a request from the non-MO interface. However, a command in the MO unit from the MO interface must be processed so as to be related to a command unit in the non-MO interface. In such a case, since the command unit of the non-MO interface has a course tendency as compared to that of the MO interface, there is a problem in that an appropriate function of the common processing unit 55 cannot be provided in response to the request from the MO interface.
Additionally, if a pointer attribute defined by the MO interface is handled in the common processing unit 55, it is considered to set a definition of various pointers that indicates a relationship between the instances so as to perform processes according to the definition. However, in order to respond to the request, a large process load is applied to the common processing unit 55. Additionally, there is a problem in that a long time and labor are required to develop a program performing such an operation.
It is a general object of the present invention to provide an improved and useful system managing method and apparatus in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a system managing method and apparatus in which a load applied to a common processing unit is decreased so as to improve a managing ability of the system.
In order to achieve the above-mentioned objects, there is provided according to the present invention a system managing method and apparatus for managing a system having a plurality of interfaces including a managed object interface and a non-managed object interface, the managed object interface handling resources as managed objects, the non-managed object interface handling resources as non-managed objects. A common processing unit performs operations common to the plurality of interfaces. A managed object interface agent is connected to the managed object interface so as to manage pointer attributes independently from the common processing unit. A non-managed object interface agent is connected to the non-managed object interface. The managed object interface agent includes a knowledge database and an agent database, the knowledge database storing information regarding a pointing instance and a pointed instance defined by each pointer attribute, the agent database holding the resources as instances of the managed object type so as to delete, add or update a value of each pointer attribute according to a process request.
According to the present invention, the pointer attributes can be processed solely by the managed object interface agent. That is, when a process request is transferred from the non-managed object interface agent to the common processing unit, the common processing unit determines whether or not the request is for the resources managed by the managed object interface. If the request is for the resources managed by the managed object interface, the common processing unit transfers the process request to the managed object interface agent so that the request is processed by the managed object interface agent. Thus, the common processing unit is not required to process the request for the resources managed by the managed object interface agent. That is, the common processing unit is required to perform only processes related to the non-managed object and basic processes common to the managed object and the non-managed object. This reduces a load to the common processing unit when a plurality of interfaces including the managed object interface and the non-managed object interface are present.


The present disclosure pertains to thermostats and particularly to mode changes between heat and cool of thermostats.


1. Field of the Invention
The present invention relates to image processing technology employing shooting information at the time of shooting, and image processing control information that designates image processing conditions to be used when performing image processing on image data.
2. Description of Related Art
To date, there have been proposed techniques for performing image processing of image data created by an image data generating apparatus such as a digital still camera (DSC), which involve performing image processing with reference to shooting information (shooting conditions) at the time of shooting, and image processing control information that designates processing conditions to be used during image processing. Shooting information and image processing control information is typically described in the header of the image data, and is associated with a particular set of image data.
According to this image processing technique, where shooting information is used, it becomes possible to perform on image data image processing that is adapted to the shooting conditions, thus preventing image processing that is inappropriate for a particular type of photographed scene, for example. Where image processing control information is used, it becomes possible to perform on image data image processing based on certain image processing conditions contemplated at the time of shooting, so that output images reflect the photographer's intention or the DSC vendor's design.
With the prior art image processing apparatus, however, since the idea was to use either shooting information or image processing control information, if an image processing apparatus were designed to be capable of image processing using image processing control information, it could not utilize shooting information, even if such information were associated with the image data.
Also, in the event that a portion of one set of information cannot be used, if the other set of information includes information corresponding to the information that cannot be used, it will not be possible to use the aforementioned information. Accordingly, there is a need to perform image processing in an appropriate manner, that mutually utilizes, in an effective manner, shooting information and image processing control information.


This disclosure generally relates to systems and methods for wireless communications, and more particularly relates to systems and methods for connecting devices through intermediate nodes.
In various situations, stable and reliable cellular, satellite and Internet connections can all be unavailable. In order to provide connectivity to wireless devices without cellular, satellite and Internet connections, wireless devices may communicate between each other through a mesh of devices connected through a local mesh network.
A wireless communication network can be realized through the use of a mesh network. A mesh network is a distributed network having multiple wireless mesh points or wireless nodes. Each mesh wireless node in the mesh network may act as a relay node capable of receiving wireless signals and relaying the wireless signals to the next mesh wireless node in the mesh network. A wireless signal may proceed from an origination mesh wireless node to a destination mesh wireless node by hopping from one mesh wireless node to another mesh wireless node. Existing systems and methods for routing wireless signals through the mesh network need to insure that the signals are routed efficiently from their origination mesh wireless node to their destination mesh wireless node.


As biotechnology advances, the making of fermentation products by use of bioreactors utilizing immobilized microorganisms is under study in the fields of brewing for malt alcohol beverages (beers), wines, sake, vinegar, soy sauce, and the like. When a bioreactor is used as such, the following are expected:
1) Since a high concentration of yeast is immobilized to carry out fermentation, the brewing is completed rapidly, so that the brewing period can be shortened, whereby the number of manufacturing tanks and the cost of construction can be lowered.
2) Since continuous fermentation is possible, it is unnecessary to charge and collect yeast.
Conventionally, when a beer or the like is manufactured by use of a bioreactor, however, the amount of amino acids and diacetyl (DA) has become greater, and the amount of ester has become smaller in the product as compared with a product manufactured by a traditional batch fermentation method. As a result, the product obtained by use of the bioreactor has been problematic in that it is disadvantageous in flavor, and this problem has been remarkable in particular when the bioreactor is used for primary fermentation (main fermentation).
For overcoming such a problem, studies have conventionally been carried out. Japanese Patent Application Laid-Open Gazette No. HEI 7-123969 discloses a method in which a fermentation liquid is circulated in a continuous fermentation method using a fluidized bed type reactor. Though the consumption of amino acids in the fermentation process is ameliorated by this method, the amount of diacetyl which causes raw odor or immature odor is not lowered sufficiently, whereby the resulting product still has room for improvement in terms of flavor. Also, manufacturing methods in bioreactors including this method have been problematic in that the number of floating yeast cells upon the end (completion) of primary fermentation is small in general, the fermentation rate in the process of fermentation is unstable, and they are hard to control.
Meanwhile, it has conventionally been known that yeast for making a fermentation product such as beer is required to have flocculation ability (agglutinability) to a certain extent. Here, flocculation ability refers to a property in which yeast cells flocculate as a mass upon the end of fermentation and are separated from the liquid so as to float up or sediment. If the flocculation ability is too high, then the flocculation occurs at an earlier stage, so that the contact between the fermentation liquid and yeast is broken, whereby fermentation becomes insufficient. If the flocculation ability is too low, by contrast, then yeast floats in the liquid for a long time, so that the amount of recovery of yeast decreases, which takes unnecessary time and labor for separating and collecting yeast by centrifuge or the like, for example. Therefore, it has conventionally been common knowledge to use yeast having a certain degree of flocculation ability (flocculent yeast) for making a fermentation product. Such flocculent yeast (agglutinative yeast) is used in the above-mentioned method disclosed in Japanese Patent Application Laid-Open Gazette No. HEI 7-123969 as well.
In view of the above-mentioned problems in the prior art, it is an object of the present invention to provide a method in which, when making a fermentation product by use of a bioreactor utilizing an immobilized microorganism, the fermentation rate in the fermentation process can be held constant, and the number of floating yeast cells upon the end of fermentation can stably be maintained at a level higher than the conventional one, whereby, when making a malt alcohol beverage by use of a bioreactor in particular, the amount of diacetyl in the fermentation liquid and final product can be lowered sufficiently and so forth, so as to improve the flavor of final product.


1. Field of the Invention
The present invention relates to failure prediction for disk drives. In particular, the present invention relates to predicting failure of remote disk drives at a central processing facility using an evolving disk drive failure prediction algorithm.
2. Description of the Prior Art
Predicting impending failure of disk drives deployed in-the-field helps protect against catastrophic data loss, for example, by suggesting an end user back-up and/or replace the failing disk drive. Another application of disk drive failure prediction is preemptive maintenance of consumer electronics devices that utilize disk drives, such as personal digital assistants (PDAs), digital cameras, personal video recorders (PVRs), and the like. For example, if the failure prediction algorithm indicates impending failure, the end user may return the consumer electronic device to the vendor for repair or replacement.
In the past, failure prediction algorithms have been implemented within each disk drive wherein the disk drive itself issues a warning when failure is imminent. An example of a failure prediction algorithm implemented within a disk drive is the Self-Monitoring Analysis and Reporting Technology (SMART), which monitors a number of quality metric values (e.g., fly-height), and reports an impending failure if any one of the quality metric values exceeds some predetermined threshold. A problem with internally implemented failure prediction algorithms, such as SMART, is their limited degree of sophistication which increases the likelihood that impending failures are not detected leading to catastrophic data loss, or that impending failures are falsely detected (false alarm) leading to unnecessary and costly remedial action.
There is, therefore, a need to improve upon disk drive failure prediction so as to increase the failure prediction accuracy while minimizing the number of false alarms.


Field of the Invention
The present invention relates, in general, to toys. A long-time favorite toy is formed with two buttons or disks rotatably mounted on a continuous loop of string. The ends of the loop of string are grasped by the hands of the user and the string is rotated about a horizontal axis between the user's hands to wind up the string. Then, in and out reciprocating movement of the ends of the strings causes the string to unwind and rewind which forces the disks to oscillate back and forth along the string and strike each other.
While this toy provides long periods of enjoyment, it is not without a disadvantage. Since the user employs his or her fingers to grasp the ends of the loop of string, the fingers are susceptible to being pinched by the winding and unwinding action of the string. Looping the ends of the string through rings which the user grasps eliminates any pinching of the user's fingers. However, the string is typically tied to one of the rings which causes unequal tension in the upper and lower portions of the string during the unwinding and rewinding of the string and prevents the string from continuously rewinding. Thus, long term repeated use of such a toy has not been possible.
Thus, it would be desirable to provide a rotatable disk string toy which includes means to facilitate easy handling of the string. It would also be desirable to provide a rotatable disk string toy with string holding means which is easily attached to the toy. It would also be desirable to provide a rotating disk string toy which includes string holding means having an inexpensive cost. It would also be desirable to provide a rotating disk string toy which is durable for a long useful life. Finally, it would be desirable to provide a rotatable disk string toy which provides a unique visual appearance when in use.


For aluminium production, technology based on a carbothermic process is promising and offers the prospect of an alternative to the Hall-Héroult electrolytic technology. A successful carbothermic process would have the potential to reduce capital investment requirements by 50 to 70% and operating costs by 25 to 35% compared to the electrolytic route. Also, the problem of fluoride emission would be obviated, while the quantity of generated carbon containing gases would be substantially lower than for electrolytic production of aluminium.
Attempts to produce aluminium by a carbothermic process have been made for in excess of 100 years. However, optimisation of a carbothermic process to enable successful commercial production of aluminium is yet to be achieved.
Processes investigated to this stage require temperatures in excess of 2000° C. and accurate control of reactants and products at different complex stages. The stages include:                (a) reaction of alumina and carbon to produce aluminium carbide at above 2000° C.;        (b) reaction of the aluminium carbide with alumina to produce aluminium metal at above 2150° C.; and        (c) separation of the aluminium from remaining materials.
Challenges to be met in such carbothermic process include successfully recovering the high level of volatilized aluminium, reducing the level of refractory loss, the difficulties of transferring materials between stages and the problem of generation of a high volume of carbon monoxide. Such issues are inevitable at operating temperatures as high as 2000 to 2250° C.
Reactions central to the carbothermic processes are:2Al2O3+9C→Al4C3+6CO,  (1) andAl2O3+Al4C3→6Al+3CO  (2)
These reactions give the overall reaction of:Al2O3+3C→2Al+3CO  (3)
Earlier work on the production of aluminium by these reactions is illustrated by U.S. Pat. Nos. 1,219,797 and 1,222,593 both to Barnet et al; U.S. Pat. Nos. 2,090,451 and 2,255,549 both to Kruh; U.S. Pat. No. 2,755,178 to Rasmussen; U.S. Pat. No. 2,776,884 to Grunert alone; and U.S. Pat. No. 2,829,961 to Miller at al; and U.S. Pat. No. 2,974,032 to Grunert. More recent work has been directed to reacting alumina and carbon in a molten bath having a molten slag of aluminium carbide and alumina. The molten bath usually operates with two zones, in a first of which aluminium carbide is generated, and a second to which the carbide passes to be reacted with alumina to produce metallic aluminium. This work is illustrated by U.S. Pat. No. 4,385,930 to Persson; U.S. Pat. No. 6,440,193 to Johansen et al; U.S. Pat. No. 6,475,260 to LaCarmera; U.S. Pat. No. 6,530,970 to Lindstad; U.S. Pat. No. 6,849,101 to Fruehan et al; and US patent application publication 2006/0042413. Also of interest are the publications: “Carbothermal Production of Aluminium” by Motzfeldt et al, published in 1989 by Aluminium-Verlag GmbH of Düsseldorf, Germany; and “Aluminium Carbothermic Technology” submitted to US Department of Energy under Cooperative Agreement Number DE-FC36-00ID13900 by M J Bruno and Alcoa Inc, and dated 31 Dec. 2004.


1. Field of the Invention
The present invention relates to a semiconductor device having circuits structured by electric field effect transistors (FETs), for example, thin film transistors (TFTs), and to a method of manufacturing the semiconductor device. The present invention relates, for example, to a semiconductor device, typically a liquid crystal display panel, and to an electronic device in which such a semiconductor device is mounted as its component.
Note that, throughout this specification, the term electro-optical device indicates general devices for performing shading display by changing an electrical signal, and that liquid crystal display devices and display devices using electroluminescence (EL) are included in the category of electro-optical device.
Note also that, throughout this specification, the term element substrate indicates general substrates on which active elements such as TFTs and MIMs are formed.
2. Description of the Related Art
Techniques of structuring thin film transistors using semiconductor thin films (having thicknesses on the order of several nm to several hundred nm) formed on a substrate having an insulating surface have been focused upon in recent years. The thin film transistors are being widely applied to electronic devices like ICs and semiconductor devices, and in particular, their development has accelerated rapidly as switching elements of liquid crystal display devices.
Liquid crystal display devices are known to be roughly divided into active matrix types and passive matrix types.
A high-grade image can be obtained with active matrix liquid crystal display devices using TFTs as switching elements. Active matrix applications are generally to notebook type personal computers, but they are also expected to be used in televisions for a home and in portable information terminals.
The active matrix liquid crystal display devices are generally driven by line inversion drive. With the line inversion drive, for example source line inversion drive, the polarity of voltages applied to adjacent source lines differs, as shown in FIGS. 37A and 37B, and the polarity of the voltage applied to each source line changes each frame. FIGS. 37A and 37B show the polarity of voltages applied to pixels during the source line inversion drive. Drive in which the polarity of the voltage differs for each adjacent source line is referred to as the source line inversion drive. Drive in which the polarity of the voltage differs for each adjacent gate line is referred to as gate line inversion drive.
FIG. 10 shows schematically a cross section of a pixel portion of a liquid crystal display device. An electric field formed between pixel electrodes 102a and 102b formed on a substrate 101, and an opposing electrode 103 formed on an opposing substrate 104, as shown in FIG. 10, is referred to as a vertical direction electric field 105 in this specification. Further, an electric field formed between the adjacent pixel electrodes 102a and 102b is referred to as a horizontal direction electric field 106 in this specification.
Liquid crystals in the vicinity of the pixel electrodes orient themselves along the horizontal direction electric field if the line inversion drive is performed, the liquid crystal orientation in edge portions of the pixel electrodes becomes nonuniform, and disclinations develop. In order to obtain a good quality black level, light shielding films for covering the disclinations are necessary. However, the aperture ratio drops if the disclinations are covered by the light shielding films. It is necessary to come up with a scheme in which a good quality black level can be obtained, and as little disclination as possible develops when displaying a high aperture ratio, bright image. Note that, in this specification, liquid crystal orientation irregularities developing due to differences in the direction of the pre-tilt angle, and differences in the twist direction, at liquid crystal orientation film interfaces are referred to as xe2x80x9cdisclinationsxe2x80x9d. Further, regions having different brightnesses produced due to an irregular orientation state of the liquid crystals when a polarization plate is formed is referred to as xe2x80x9clight leakagexe2x80x9d.
In particular, the occupied ratio of pixels in which disclinations and light leakage developing due to horizontal direction electric fields is large enough that it cannot be ignored in liquid crystal display devices in which the pixels are formed at a very fine pitch, such as that of a projecting liquid crystal display device. Further, these disclinations and light leakage are expanded when projected onto a screen with the projecting liquid crystal display device, and therefore whether or not the light leakage and disclinations can be suppressed is vital in maintaining contrast.
An object of the present invention is to provide an element structure such that liquid crystal disclination and light leakage can be stopped in an active matrix liquid crystal display device.
The following measures are taken in order to solve the above stated problems with the conventional technique.
Overlapping edge portions of pixel electrodes with predetermined height convex portions.
FIG. 2 is a cross sectional diagram of a simulation model. The present invention utilizes moving disclinations and light leakage, which are caused when a voltage is applied to liquid crystal 202, to edge portions of pixel electrodes by forming edge portions of pixel electrodes 203a and 203b on a first substrate (not shown) so as to overlap with convex portions 204 formed on a level surface as shown in FIG. 2. An opposing electrode 201 is formed in an opposing substrate 207.
Note that, in this specification, the convex portions are formed selectively below the pixel electrodes. Regions in which the pixel electrodes overlap with upper edge portions of the convex portions are referred to as first regions (a) of the pixel electrodes. Regions in which the pixel electrodes are formed in side portions of the convex portions are referred to as second regions (b) of the pixel electrodes. Regions in which the pixel electrodes are formed on a level surface, and which contact the second regions of the pixel electrodes, are referred to as third regions (c) of the pixel electrodes.
Further, the height (h) of the convex portions is the maximum value of the length of a vertical line formed from the upper edge portions of the convex portions to the level surface on which the convex portions are formed.
In addition, a cell gap (d) is the distance from the opposing electrode formed on the opposing substrate (second substrate) to the third region of the pixel electrode.
An inter-pixel electrode distance (s) is the distance between the first regions of mutually adjacent pixel electrodes.
Conventionally, if there are convex portions in the orientation surface of liquid crystals, then the orientation of the liquid crystal is disordered and light leakage develop at the convex portions, and therefore it is thought that a liquid crystal orientation surface should be as level as possible. However, the applicants of the present invention found that when the first regions of the pixel electrodes formed on the convex portions having a predetermined height, and the second regions of the pixel electrodes formed on the side portions of the convex portions having a predetermined height, are present, simulation results on the liquid crystal orientation show that liquid crystal orientation irregularities caused by the horizontal direction electric field in driving a liquid crystal display device can be reduced. Specifically, locations at which disclinations and light-leakage appear are in the edges of the pixel electrodes during black display.
This phenomenon is explained by the schematic diagrams of FIGS. 1A to 1C which show the principles of the present invention. The liquid crystal orientation method is taken as a TN method. FIGS. 1A to 1C show liquid crystal orientations when driving a liquid crystal display device by a 5 V or xe2x88x925 V video voltage with line inversion drive. An orientation film is not shown in the figures.
First, as shown in FIG. 1A, if edge portions of the pixel electrodes 203a and 203b formed on the first substrate (not shown in the figures) are formed on the convex portion 204, then it becomes more difficult for disclinations to develop, compared to the case where no convex portion presents. Nevertheless, if the height of the convex portion is low, then the influence of a horizontal direction electric field formed between the pixel electrode 203a and the pixel electrode 203b is strong with respect to a vertical direction electric field formed between the pixel electrodes 203a and 203b and the opposing electrode 201 formed on the second substrate (not shown in the figures). Liquid crystal molecules 208 in the vicinity of the convex portion orient with an inclination in a diagonal direction with respect to the substrate surface. Thus, light leakage can be seen below a cross Nicol polarization plate. Further, a pre-tilt angle of liquid crystal molecules 209 in the vicinity of the interface of the orientation film is determined by rubbing directions 205 and 206, and therefore a disclination 210 having high light strength is formed at the point where the direction of the horizontal direction electric field in the vicinity of the interface differs from the direction of the liquid crystal molecules in the vicinity of the interface due to rubbing.
However, the higher the convex portion becomes, the more the position at which the disclination 210 seen in FIG. 1A appears changes to the edge of the pixel electrode. In addition, if the convex portion 204 overlapping with the edge portions of the pixel electrodes 203a and 203b is made higher, then a vertical direction electric field formed between a first region 215 of the pixel electrode and the opposing electrode 201 becomes stronger with increasing the height of the convex portion, as shown in FIG. 1B, and the influence of the horizontal direction electric field becomes weaker. Several vertical direction electric fields are formed almost in the substrate surface by an electric field formed between a second region 212 of the pixel electrode, among the pixel electrodes 203a and 203b, formed in the side portion of the convex portion and the opposing electrode 201. TN method liquid crystals are positive type liquid crystals, and therefore the longitudinal axes of liquid crystal molecules 211 orient parallel to the electric fields. Disclination and light leakage in the vicinity of the convex portion is thus reduced.
Next, as shown in FIG. 1C, if the height of the convex portion 204 is made higher, then the liquid crystals on the pixel electrode 203b form an electric field having a direction diagonal with respect to the substrate surface, the same direction as the pretilt angle, between the opposing electrode and the second region of the pixels. Thus, liquid crystal molecules 213 orient diagonally with respect to the substrate surface, along the electric field, and a light leakage having a width which cannot be ignored is formed in the vicinity of the convex portion. On the pixel electrode 203a, an electric field having a direction diagonal with respect to the substrate surface and formed between a second region 216 of the pixel electrode and the opposing electrode is opposite to the direction of the pre-tilt angle of the liquid crystals, and therefore it is difficult for liquid crystals 217 to follow the electric field, and formation of light leakage becomes relatively difficult. However, the width of the light leakage formed due to the electric field formed between the opposing electrode and the second region 212 of the pixel electrode 203b becomes wider, and overall, the aperture ratio drops.
It can be understood from the above that the optimal value of the height of the convex portion exists in order to reduce both the disclination of black display and the width of the light leakage when the edge portions of the pixel electrodes are formed on the convex portion. If the convex portion is too tall, then overall, the width of the light leakage will become larger (see FIG. 1C.) The structures of FIG. 1A and FIG. 1B can increase the aperture ration. The subsequent simulation results substantiate these principles.
The optimal value of the height of the convex portion can be considered to be determined with a cell gap (namely, an element for determining the strength of the vertical direction electric field) as a parameter.
The applicants of the present invention performed simulations, and confirmed the optimal value of the convex portion height.
Disclination and light leakage due to horizontal direction electric fields become problems in particular when the pixel area is small, and the proportion of the pixel occupied by the disclination and the light leakage is large enough that it cannot be ignored. In other words, mainly for cases where the device is used as a projection liquid crystal display device. Projection liquid crystal display devices have a small pixel pitch, and inevitably the distance between the pixel electrodes is small at 4.0 xcexcm or less. The applicants of the present invention performed simulations focusing on inter-pixel electrode distances of equal to or less than 4.0 xcexcm in order to reduce the disclination and the light leakage in the projection liquid crystal display device.
A simulation model is shown in FIG. 2. The opposing electrode 201, the liquid crystals 202, the convex portion 204, and the pixel electrodes 203a and 203b become the structural elements of the simulation model in FIG. 2. The simulation model of FIG. 2 was taken as one unit, and periodically repeated.
The simulation parameters are as follows:
cell gap, d: 4.5 xcexcm, 3.0 xcexcm;
distance between pixel electrodes, s: 2 xcexcm, 4 xcexcm;
convex portion height, h: 0 xcexcm, 0.2 xcexcm, 0.3 xcexcm, 0.4 xcexcm, 0.5 xcexcm, 0.7 xcexcm, 1.0 xcexcm, and 1.5 xcexcm; and
pixel pitch, p: 18 xcexcm, 43 xcexcm.
Fixed conditions in the simulations are as follows:
width of first region of pixel electrode, o: 1.0 xcexcm;
electric potential of the pixel electrode 203a: +5 V;
electric potential of the pixel electrode 203b: xe2x88x925 V; and
electric potential of the opposing electrode 201: 0 V.
In order to generalize the relationship between the distance s between pixel electrodes, the cell gap d, and the height h of the convex portion on which the edge portion of the pixel electrode is formed, the simulation was performed with cell gaps of 4.5 xcexcm and 3.0 xcexcm. ZLI4792 was used for the liquid crystals for both cell gaps, 4.5 xcexcm and 3.0 xcexcm, and the orientation was found by computation.
The pre-tilt angle of the liquid crystals was set to 6.0xc2x0, and the chiral pitch was set to left handed at 70 xcexcm. The rubbing direction 205 and 206 are shown in FIG. 2. The twist angle is 90xc2x0. The orientation of the liquid crystal is TN method.
Further, in order to increase the number of evaluations and grasp the tendencies, the simulations were performed as stated above with two pixel pitches.
Liquid crystal orientation simulation software from Syntech Corp. entitled LCD Master 2SBENCH was used, and simulations of the liquid crystal orientation ware run. 2SBENCH shows the liquid crystal orientation by a two-dimensional planer surface composed of the cell cap direction and the substrate surface direction.
The simulation results are as shown below. FIGS. 3 to 8 are partial blowup diagrams of the simulation results.
FIGS. 3 to 8 are simulations in which the height of the convex portion was changed at conditions of the gap d set to 4.5 xcexcm, the inter-pixel spacing distance s set to 2.0 xcexcm, and the pixel pitch p set to 18 xcexcm. The transmittivity in each coordinate, calculated from equipotential lines, liquid crystal directors, and index of refraction anisotropy, is shown. The pixel electrode 203a has coordinates from 1 to 17 xcexcm, and the pixel electrode 203b has coordinates from 19 to 35 xcexcm, and FIGS. 3 to 8 show blowups of the points at which there is light leakage and disclination in the vicinity of the convex portion. The liquid crystal is a positive type, and therefore lines of electric force can be considered to have nearly the same direction as the director of the liquid crystals.
The orientation of the liquid crystals on a pixel electrode having a xe2x88x925V electric potential is explained below.
A horizontal electric field is formed up through a region entering the inside of the pixel electrode when there is no convex portion, as shown in FIG. 3. Further, disclinations develop in regions in which the direction of the horizontal electric field and the direction of the liquid crystal pre-tile angle are opposite.
When the height of the convex portion is 0.3 xcexcm, the vertical direction electric field becomes stronger due to the first region of the pixel electrode formed in the upper edge portion of the convex portion, and therefore the position of the disclination moves toward the outside of the pixel electrode, as shown in FIG. 4, compared with the case of no convex portion in FIG. 3.
If the height of the convex portion becomes taller at 0.7 xcexcm, as shown in FIG. 5, then there are many liquid crystals which become oriented perpendicular to the substrate along the lines of electric force due to the effect of the horizontal direction electric field becoming stronger, and due to the effect of the electric force lines, due to the second region of the pixel electrode formed in the side portion of the convex portion and the opposing electrode, possessing components nearly perpendicular with respect to the substrate surface. The disclination in the vicinity of the convex portion becomes less.
When the height of the convex portion becomes higher at 1.0 xcexcm, the width of the disclination in the vicinity of the convex portion drops by just 0.2 xcexcm compared with the case in which the convex portion height is 0.7 xcexcm, as shown in FIG. 6.
As shown in FIG. 7, the lines of electric force formed by the second region of the pixel electrode formed in side portion of the convex portion, and by the opposing electrode, possess an angle order of 60xc2x0, with respect to the substrate surface, in the vicinity of the convex portion, which becomes at 1.5 xcexcm. The liquid crystals orient along the electric force lines, and light leakage is formed near the convex portion.
Note that the angle of the electric force lines with respect to the substrate surface is estimated from the distribution of equipotential lines.
In FIG. 8, the height of the convex portion increases to 3.0 xcexcm, and the vertical direction electric field becomes stronger. The liquid crystals on the third region of the pixel electrode of the edge portion of the convex portion therefore orient nearly perpendicular to the surface of the substrate. However, the electric field formed between the second region of the pixel electrode formed in the side portion of the convex portion, and the substrate surface, possesses an angle on the order of 30xc2x0, with respect to the substrate surface, and the liquid crystals orient along the lines of electric force. Broad light leakage is consequently formed in the vicinity of the convex portion.
The orientation of the liquid crystals of FIG. 4 corresponds to the schematic diagram of FIG. 1A. The orientation of the liquid crystals of FIG. 5 and FIG. 6 corresponds to the schematic diagram of FIG. 1B, and the orientation of the liquid crystals of FIG. 7 and FIG. 8 corresponds to the schematic diagram of FIG. 1C. Namely, it is confirmed that the light leakage of the liquid crystals becomes larger if the height of the convex portion exceeds an upper limit.
In order to improve the display quality, a systematic simulation was performed. The distance between one edge portion and another edge portion of the disclination and the light leakage influencing the aperture ratio was paid attention to.
Data was also taken regarding the light leakage and the disclination width of a pixel electrode having a xe2x88x925 V electric potential. This is because the light leakage and the disclination of a pixel electrode having a xe2x88x925 V electric potential greatly influences the display quality due to high light strength.
FIG. 9 and FIG. 36 show the simulation results. FIG. 9 is a figure in which the height h of the convex portion, the light leakage and the disclination width x are graphed with respect to the cell gap d in the simulation model of FIG. 2. The term light leakage and disclination width x denotes the width of a region having high brightness due to disclination and light leakage formed on both sides of the convex portion.
FIG. 36 is a figure in which the height h of the convex portion, and the light leakage and the disclination width y are graphed with respect to the cell gap d in the simulation model of FIG. 2. The term light leakage and disclination width y denotes the width of a region having high brightness due to disclination and light leakage formed in one side of the convex portion, namely in an electrode side having a xe2x88x925 V electric potential.
Simulations were performed with the pixel pitch p set to 18 xcexcm and 43 xcexcm when the cell gap was 4.5 xcexcm. Further, the distance s between adjacent pixel electrodes was set to 2.0 xcexcm or to 4.0 xcexcm.
When the cell gap was 3.0 xcexcm, the distance s between adjacent pixel electrodes was set to 2.0 xcexcm or 4.0 xcexcm. The pixel pitch p was set to 18 xcexcm.
The relationship between the convex portion height, and the width of the light leakage and the disclination shows similar tendencies in both FIG. 9 and FIG. 36.
First, the relationship between the convex portion height and the light leakage and disclination width nearly did not change in accordance to pixel pitch. This is because formation of light leakage and disclination is a phenomenon caused by the horizontal direction electric field and the vertical direction electric field of the edge portions of the pixel electrodes.
Further, light leakage and disclination become relatively less with a smaller distance between adjacent pixel electrodes.
The regions of orientation irregularities of the liquid crystals, typically light leakage and disclination, are reduced along with increasing height of the pixel portion, and are not due to the pixel pitch p and the cell gap d, in both FIG. 9 and FIG. 36. If the height of the convex portion becomes too tall, there are conversely more regions of orientation irregularities. An optimal convex portion height is determined by the distance between the cell gap and the pixel electrode.
Considering the inflection point of the graph, it is preferable that the height of the convex portion in which the effect of a reduction in the liquid crystal regions having orientation irregularities appears significantly, be equal to or greater than 4.4% of the cell gap, and equal to or less than 22.5% of the cell gap when the call gap is 4.5 xcexcm.
When the cell gap is 3.0 xcexcm as well, and the distance s between the pixel electrodes is equal to or less than 2.0 xcexcm, a good effect of reducing, compared to a case in which there is no convex portion, the regions having orientation irregularities can be obtained by setting the height of the convex portion to be equal to or greater than 4.4% of the cell gap, and equal to or less than 22.5% of the cell gap.
If the height of the convex portion is less than 4.4% with respect to the cell gap, then the width of the light leakage and the disclination does not change much, even if the height of the convex portion is increased. If the height of the convex portion exceeds 22.5% to the cell gap, then the light leakage and the disclination width increases.
Further, orientation irregularities of the liquid crystals easily develop due to rubbing non-uniformity if the convex portion is high, and therefore reducing the height of the convex portion, thereby reducing the light leakage and the disclination width, is preferable to insure display quality. Consequently, for a case in which the cell gap is 4.5 xcexcm, the height of the convex portion may be suppressed to be greater than or equal to 4.4% of the cell gap, and less than or equal to 15.6% of the cell gap. Nearly equal light leakage and disclination reduction effects are obtained when the height of the convex portion is with the range of greater than or equal to 4.4%, and less than or equal to 22.5%, of the cell gap.
Further, when the cell cap is 3.0 xcexcm and the distance s between the pixel electrodes is equal to or less than 2.0 xcexcm, a good effect of reducing the light leakage and the disclination is obtained when the height of the convex portion is greater than or equal to 4.4% of the cell gap, and less than or equal to 15.6% of the cell gap, the same as when the height of the convex portion was set equal to or greater than 4.4%, and equal to or less than 22.5%, of the cell gap.
Conversely, there was more light leakage when the height of the convex portion was 22.5% when the distance s between the pixel electrodes was set to 4.0 xcexcm. Inclusive of when the distance between the pixel electrodes is 4.0 xcexcm, it is therefore preferable that the height of the convex portion be equal to or greater than 4.4%, and equal to or less than 15.6%, or the cell gap.
In other words, under conditions of the distance between the pixel electrodes being equal to or less than 4.0 xcexcm, the height of the convex portion may be set equal to or greater than 4.4%, and equal to or less than 22.5%, of the cell gap when the cell gap is equal to or greater than 3.0 xcexcm, and equal to or less than 4.5 xcexcm. The height of the convex portion is preferably set greater than or equal to 4.4%, and less than or equal to 15.6%, of the cell gap.
The smaller the cell gap, the smaller the height of the convex portion needed for reducing the light leakage and the disclination width. For cases of the call gap being from 3.0 xcexcm to 4.5 xcexcm, good liquid crystal orientation can be obtained with a convex portion height of 15.6% or less. For cases of the cell gap being less than 3.0 xcexcm, it is therefore considered that the necessary convex portion height will be 15.6% or less to sufficiently reduce the light leakage and disclination width.
The height of the convex portion may be set equal to or less than 15.6% of the cell gap when the cell gap is less than or equal to 3.0 xcexcm. Of course, considering the inflection point of the graph, it can be expected that a good effect will also be obtained if the height of the convex portion is set equal to or less than 6.7% of the cell gap.
When the cell gap is 3.0 xcexcm, the light leakage and the disclination width are monotonically reduced as the convex portion becomes higher, provided that the height of the convex portion is equal to or less than 6.7% with respect to the cell gap. If the cell gap is made smaller at less than or equal to 3.0 xcexcm, it can be considered that the region in which the light leakage and the disclination width are monotonically reduced with increasing convex portion height is in a range in which the height of the convex portion does not exceed 6.7% with respect to the cell gap.
An upper limit to the height of the convex portion, or both upper and lower limits, can thus be determined. There is a concern that rubbing irregularities may occur if the fiber tips of a rubbing cloth are disordered, and therefore the determination of an upper limit for the height of the convex portion is necessary in order to manufacture a liquid crystal panel. Further, the optimal value of the height of the convex portion with respect to the cell gap tends to become smaller as the cell gap becomes smaller.
An optimal value for the height of the convex portion thus determined can be used not only for the TN method, but can also be widely used as means for hiding liquid crystal disclination in a normally white mode orientation method.
The optimal value of the convex portion height is one in which the lines of electric force formed by a horizontal direction electric field and a vertical direction electric field of an active matrix liquid crystal display device are suitably regulated, and as shown in FIG. 1B, one in which regions with generated electric force lines possessing components perpendicular to the surface of the substrate are increased in the edge portions of the pixel electrode.
Therefore, although the simulations were performed for a transmitting type liquid crystal display device, it can be considered possible to apply the present invention to a reflective type liquid crystal display device as well. This is because a voltage may also be applied to the pixel electrodes with a reflective type liquid crystal display device, and when orienting the liquid crystals by a vertical direction electric field, unnecessary electric fields directed diagonally with respect to the substrate surface are reduced, and light leakage and disclination of the edge portions of the pixel electrodes can be reduced.
Further, the simulation was made using the TN method, but the liquid crystal orientation method is not limited to the TN method. This is because, in an active matrix liquid crystal display device, unnecessary electric fields directed diagonally with respect to the substrate surface can be reduced by optimizing the convex portion height when orienting the liquid crystals by using a vertical direction electric field. For example, it is considered that it is possible to apply the present invention to methods such as an OCB (optically controlled birefringence) method, an STN method, and an EC method using homogeneously oriented cells.
Further, provided that orientation faults are not induced in the liquid crystals by the convex portion, it is thought that it is also possible to apply the present invention to an orientation method using sumectic liquid crystals. For example, it is possible to apply the present invention to a liquid crystal display device using ferroelectric liquid crystals or anti-ferroelectric liquid crystals. Further, by adding high molecular weight molecules with liquid crystal properties to these liquid crystals, it is thought that it is also possible to apply the present invention to liquid crystal display devices using materials hardened by irradiation of light (for example, ultraviolet light).
The simulations were performed with an angle 90xc2x0 (hereafter referred to as a convex portion taper angle) formed between the surface contacting the second region of the pixel electrode formed in the side surface of the convex portion, and the third region of the pixel electrode formed in the level surface. However, it is also possible to apply the present invention if the convex portion taper angle is less than 90xc2x0. As shown in the cross sectional diagram of FIG. 35 for the lines of electric force when the convex portion has a taper, the electric force lines are generated in a direction perpendicular to a conductor for cases in which the taper angle xcex8 of the convex portion 204 is less than 90xc2x0, and therefore the bend of electric force lines 218 formed between the opposing electrode 201 and second regions 219 of the pixel electrodes 203a and 203b becomes relaxed when the convex portion has a taper. Liquid crystals 220 orient very well perpendicular with respect to the substrate surface. A very large effect in reducing light leakage and disclination is therefore obtained, compared to when the taper angle is 90xc2x0, by using the relationship shown in the present invention between a convex portion height 221 and the cell gap when the convex portion has a taper.
Width of the first region of the pixel electrode on the upper portion of the convex portion
Next, changes in the orientation of liquid crystals when the width of the first region of the pixel electrode formed overlapping with the upper portion of the convex portion is investigated.
A simulation model is shown in FIG. 2. The opposing electrode 201, the liquid crystals 202, the convex portion 204, and the pixel electrodes 203a and 203b become the structural elements in FIG. 2.
The simulation parameters are as follows:
cell gap, d: 4.5 xcexcm;
distance between pixel electrodes, s: 2 xcexcm, 4 xcexcm;
convex portion height, h: 0 xcexcm, 0.5 xcexcm; and
width of first region of pixel electrode, o: xe2x88x921 xcexcm, xe2x88x920.5 xcexcm, 0 xcexcm, 0.5 xcexcm, 1.0 xcexcm.
The symbol for the width o of the first region of the pixel electrode, such as xe2x88x921.0 xcexcm, indicates that the pixel electrode is not formed on the convex portion, and that the edge portion of the pixel electrode is located at 1.0 xcexcm from the convex portion.
Fixed conditions in the simulations are as follows:
electric potential of the pixel electrode 203a: +5 V;
electric potential of the pixel electrode 203b: xe2x88x925 V;
electric potential of the opposing electrode 201: 0 V; and
pixel pitch, p: 18 xcexcm.
Simulation results are shown in the cross sectional diagrams of FIG. 11 to FIG. 15. The distance s between pixel electrodes is 2.0 xcexcm.
In FIG. 11, there is no convex portion. The convex portion and the pixel electrode do not mutually overlap in FIG. 12, and the edge of the pixel electrode is located 0.5 xcexcm from the edge of the convex portion. In other words, the second region of the pixel electrode and the first region of the pixel electrode do not exist in FIGS. 11 and 12. Light leakage from the edges of the pixel and the disclination width x shows no change at all at this point in FIG. 11 and FIG. 12.
The pixel electrode is formed in the side portion of the convex portion in FIG. 13. Namely, there is a second region of the pixel electrode. Compared to FIGS. 11 and 12, the position of the disclination on a pixel electrode having a xe2x88x925 V electric potential, moves 0.4 xcexcm to the pixel edge. The vertical direction electric field is made stronger, and the horizontal direction electric field becomes a little weaker due to the second region of the pixel electrode.
The first region of the pixel electrode formed in the edge portion on the convex portion, and the second region of the present invention formed in the side portion of the convex portion exist in FIG. 14. The width of the first region of the pixel electrode is 0.5 xcexcm. The vertical direction electric field becomes stronger, and the disclination on the pixel electrode having a xe2x88x925 V electric potential moves to the edge of the pixel electrode due to the first region of the pixel electrode.
The width of the first region of the pixel electrode is set to 1.0 xcexcm in FIG. 15, compared to 0.5 xcexcm in FIG. 14. The vertical direction electric field is made additionally stronger with respect to the horizontal direction electric field due to the 1.0 xcexcm width, and the disclination on the pixel electrode having a xe2x88x925 V electric potential moves to the edge of the pixel electrode.
It can thus be understood that there is a disclination reduction effect due to the existence of the first region of the pixel electrode and the second region of the pixel electrode.
Next, data is added for when the distance s between the pixel electrodes is 4.0 xcexcm, and data is systematically taken. FIGS. 16A and 16B show the simulation results. FIG. 16A is a graph of the width o of the first region of the pixel electrode, and the light leakage and the disclination width x, versus the cell gap d, in the simulation model of FIG. 2. The term light leakage and disclination width x here indicates the width of a region having high brightness causes by disclination and light leakage formed in both sides of the convex portion.
FIG. 16B is a graph of the width o and the light leakage and the disclination width y, versus the cell gap d, in the simulation model of FIG. 2. The term light leakage and disclination width y here indicates the width of a region having high brightness causes by disclination and light leakage formed in one side of the convex portion, namely in the electrode side having an electric potential of xe2x88x925 V.
From FIGS. 16A and 16B, it can be understood that there is an effect in which disclination and light leakage are reduced if the width o of the first region of the pixel electrode is equal to or greater than 0.5 xcexcm, preferably equal to or greater than 1.0 xcexcm, without dependence on the distance s between the pixel electrodes.
The light leakage and the disclination width when the width of the first region of the pixel electrode is 0 xcexcm in FIGS. 16A and 16B shows a light leakage and disclination width of a state in which the pixel electrode is only formed in the side surface of the convex portion. Compared to cases in which the width of the first region of the pixel electrode is equal to or greater than 0.5 xcexcm, or equal to or greater than 1.0 xcexcm, the effect of reducing the light leakage and the disclination width is reduced. However, compared to the case in which the width of the first region of the pixel electrode is xe2x88x920.5 xcexcm, in which the pixel electrode does not contact the convex portion at all, the light leakage and the disclination width do drop.
An actual experiment in which the width over which the convex portion and the pixel electrode overlap was carried out. FIG. 33A is an upper surface diagram of a substrate having a convex portion, and FIGS. 33B and 33C are cross sectional diagrams of the substrate having the convex portion.
Pixel electrodes 301a denoted by slanted line portions in the upper surface diagram of FIG. 33A all have the same electric potential. Further, the pixel electrodes 301b denoted by vertical line portions all have the same electric potential. This is in order to connect adjacent pixel electrodes by a transparent conducting film 300 having a width of 3 xcexcm. Assuming line inversion driving, an electric potential of +5 V is imparted to the pixel electrodes 301a. In addition, an electric potential of xe2x88x925 V is imparted to the pixel electrodes 301b. A rubbing direction 302 for the substrate having a convex structure is shown in the figures. A rubbing direction for a substrate opposing the substrate having the convex structure is perpendicular to the rubbing direction 302.
A cross section of the upper surface diagram of FIG. 33A cut along the dashed line G-Gxe2x80x2 is shown in FIG. 33B. A cross section of the upper surface diagram of FIG. 33A cut along the dashed line H-Hxe2x80x2 is shown in FIG. 33C. Identical reference symbols are used for the same portions as in FIG. 33A. The edge portions of the pixel electrode 301a and 301b formed on the substrate 303 contact a convex portion 304. The distance between the adjacent pixel electrodes 301a and 301b was set constant at 2.0 xcexcm, and the liquid crystal orientation was confirmed by changing the width of the pixel electrode overlapping on the convex portion, namely by changing the width 305 of the first region of the pixel electrode. The width of the first region of the pixel electrode was set to xe2x88x921.0 xcexcm, 0 xcexcm, 0.5 xcexcm, and 1.0 xcexcm. The cell gap was 4.5 xcexcm, the height of the convex portion was 0.5 xcexcm, and the pixel pitch was 18 xcexcm.
Photographs of the liquid crystal orientation when the pixel electrode structure of FIGS. 33A to 33C was used are shown in FIGS. 34A to 34D. The adjacent pixel electrodes in the horizontal direction of the page have the same electric potential. The rubbing direction was perpendicular to the page. An effect of reducing the disclination width was found in the experiments as well if the width o of the first region of the pixel electrodes was equal to or greater than 0.5 xcexcm, preferably equal to or greater than 1.0 xcexcm. It was found that the disclination and the light leakage width extending in the horizontal direction of the page decreases along with increases in the width o of the first region or the pixel electrodes.


The present invention relates to a multiple pocket, expandable envelope, a blank for forming a multiple pocket, expandable envelope, and a method of forming a multiple pocket, expandable envelope from a blank. More particularly, the invention relates to the use of a planar, unitary blank for forming a multiple pocket, expandable envelope which may be folded simply and inexpensively in a one pass, right angle gluing and folding operation.
In constructing envelopes or folders, it is often necessary to provide a plurality of individual pockets or compartments for separating the contents of the envelope. Additionally, the envelope must be capable of being shipped and stored in a flat, collapsed configuration to use shipping and storage space efficiently, and then expanded to receive varying amounts of contents, e.g., sheets of paper.
Conventional multiple pocket envelopes or folders are formed from a plurality of components which are automatically and manually assembled. The forming of such envelopes from a plurality of components is difficult and expensive, involving both manual steps and complex machinery.
To form multiple pocket, expandable envelopes simply, inexpensively and efficiently, such envelopes must be formed from a planar, unitary blank which may be folded and glued in one pass, right angle gluing and folding operation. Such operation eliminates manual handling and permits the envelope to be manufactured on relatively simple, conventional folding and gluing apparatus.


The present invention relates to manufacture of knife blades, and in particular relates to accurate mechanically-performed grinding of sharp edges on a series of similar knife blades.
In many knives the blade is tapered between its back and its edge by being beveled on both sides, either with a flat surface or hollow ground. It is desired in sharpening such a blade to provide a narrow edge bevel area on each side of the knife blade, ground at a somewhat steeper angle to provide the actual sharpened edge. It is desired for that narrow portion to conform closely to the profile of the blade, and for the two sides of the blade to be ground symmetrically. The edge bevel areas should be parallel with the entire knife profiles from the plunge to the tip of the blade to be cosmetically appealing.
Mass produced knife blades have slight dimensional variations resulting from the grinders used to produce the flat or hollow ground beveled side surfaces of such blades. In order to produce a desired sharp edge with symmetrical edge bevels on opposite sides of a knife whose blade has been beveled or hollow ground on both sides, it has therefore been necessary in the past for a person to hold each blade and to move the blade manually along a suitable abrasive wheel to sharpen knife blades by hand during the normal process of manufacture. That is, it has not been practical to use machines to automatically grind a final bevel surface to define a sharp edge with the necessary angle to produce a desired appearance, bevel width, and symmetry.
Some knife blade blanks intended to have serrations in an edge have been beveled flat or hollow-ground on each side to establish a tapered thickness of the blade, narrowing from the back of the blade toward the edge. The tang of such a tapered blade blank has then been clamped into a fixture, and a serrated portion of an edge has been ground into one beveled face using an abrasive wheel dressed to the shape required to provide the desired serrated edge profile. This method of holding a knife blade has not been found useful in sharpening entire knife blades during manufacture, however, because a knife blade cannot be located precisely enough by clamping the tang of the blade to form symmetrical edge bevels reliably on both sides of a blade without having to confirm or readjust the position of the blade between grinding steps. As a result, automatic sharpening of tapered knife blades has not been practical, and such blades have previously been costly because of the amount of skilled labor needed to finish the edge of each blade.
It is therefore desired to be able to grind both sides of a knife blade automatically to produce a symmetrically ground sharpened edge without having to readjust or check the blade's position in a fixture holding the blade during the process of grinding the edge.


This invention relates generally to financial services and products, and more particularly to financial systems that enable an investor to create bond laddering strategies, and other strategies that typically involve individual fixed-income securities, through a series of open-ended funds (such as exchange traded funds or mutual funds) that hold fixed-income securities.
Bond laddering is an investment technique in which an investor purchases multiple bonds (or other types of fixed-income securities) having different maturity dates. As an example, the total investment is divided equally among several maturity dates that are spread at regular intervals over a period of time (e.g., every year for a period of ten years). In this way, the bonds associated with each particular maturity date are a “rung” of the total investment “ladder.” Bond laddering has a number of benefits for investors. For example, an investor may avoid capital losses (or gains) due to fluctuations in interest rates by simply holding onto the bonds until the maturity dates arrive, at which time the investor can purchase a new rung for the bond ladder. By having a series of investments that mature over regular intervals, a bond ladder provides more stability around yields and periodic liquidity for the investor.
A bond laddering strategy may also minimize risks to the investor. For example, in an environment where interest rates are increasing, a bond ladder prevents the investor from being stuck with a low interest rate for a long time, thereby allowing the investor to benefit from the returns associated with increasing rates. On the other hand, when interest rates are decreasing, the division of the investment across several rungs of the bond ladder means that only one portion of the total bond investment (i.e., one rung of the ladder) will mature at any given time. Accordingly, if interest rates are relatively low but the investor desires to repurchase more bonds when a rung matures, only a fraction of the total portfolio will consistent of the bonds at the lower-yielding rate. As one can appreciate, by spreading out the maturity dates of the fixed-income securities over time, the ladder structure smoothes the risks associated with investing in fixed-income securities in an environment where interest rates can fluctuate.
Investors commonly invest in different types of funds to gain exposure to various types of securities, including bonds and other fixed-income securities. A very popular type of fund is an exchange-traded fund, or ETF. Shares of an ETF are securities that represent a legal right of ownership over an underlying portfolio of securities or other assets held by the issuing fund. The assets held by an ETF may include individual stocks, bonds, cash, commodities, derivatives, or any tradable asset, including contracts based on the value of any of the foregoing. Shares of an ETF are designed to be listed on a securities exchange and traded over the exchange just like other securities. ETFs thus allow an investor to own a set or “basket” of assets by simply purchasing shares in the individual ETF. Many existing ETFs hold a mix of assets that aim to replicate or otherwise match the characteristics of a particular published index. These ETFs allow investors to have exposure to the index by purchasing shares of the single ETF. Because of their low cost and tax advantages, ETFs have grown in popularity in recent years.
A typical ETF resembles an index mutual fund in that an ETF generally holds a basket of securities designed to replicate the returns of a securities index and is required to permit daily redemptions at the current value of its holdings (also known as “Net Asset Value”). But unlike mutual funds, ETF shares trade on an exchange throughout the trading day, and most investors buy and sell shares on the exchange rather than direct purchases and redemptions from the fund itself (as is the case with mutual funds). Unlike mutual funds, most transactions in ETF shares are conducted in the secondary market (i.e., on an exchange) and do not involve the movement of assets in or out of the fund. In the case of transactions in creation units that do involve the movement of assets into or out of the fund, the transactions are routinely effected by giving the redeeming shareholder their pro rata share of the fund's holdings, which does not impose trading costs or adverse tax consequences on the remaining shareholders.
Although there are many ETFs that hold bonds, existing ETF products are perpetual in nature and therefore do not enable investors to implement strategies that rely on a maturity structure such as bond laddering. Other types of funds that may hold bonds (including open-ended funds, such as mutual funds) similarly do not enable an effective bond laddering strategy. Aside from the lack of a liquidation date, this limitation is, at least in part, due to the open-ended nature of these funds. A bond laddering strategy typically relies on the ability to buy and hold a fixed-income security until its maturity date, thus allowing an investor to lock in a specific yield for each rung of the bond ladder. But with traditional open-ended funds like ETFs, there is no liquidation date and no limitation on investors' ability to enter or leave the fund, which may require the fund to buy or sell the underlying bonds when investors buy or sell shares of the fund. The lack of a liquidation date coupled with the buying and selling of the underlying bonds while interest rates are changing may result in a net change of the yield of the underlying funds and result in uncertainty for investors around the value of their investment at liquidation. These attributes have prevented traditional open-ended funds from creating a constant yield experience for each investor in the fund. As such, existing open-ended funds are unacceptable for strategies which rely upon a liquidation date and expected yield such as bond laddering.
Accordingly, it would be desirable to provide a fund management information system 110 that solves these problems by offering and managing open-ended funds (such as ETFs) that have properties allowing the funds to be used by investors to create and pursue other applications typically associated with individual fixed income securities such as bond laddering strategies.


In recent years, there are many database systems that allow storage and querying of extensible Markup Language data (“XML data”). Though there are many evolving standards for querying XML, all of them include some variation of XPath. However, database systems are usually not optimized to handle XPath queries, and the query performance of the database systems leaves much to be desired. In specific cases where an XML schema definition may be available, the structure and datatypes used in XML instance documents may be known. However, in cases where an XML schema definition is not available, and the documents to be searched do not conform to any schema, there are no efficient techniques for querying using XPath.
Some database systems may use ad-hoc mechanisms to satisfy Xpath queries that are run against documents where the schema of the documents is not known. For example, a database system may satisfy an XPath query by performing a full scan of all documents. While a full scan of all documents can be used to satisfy all XPath queries, the implementation would be very slow due to the lack of indexes.
Another way to satisfy XPath queries involves the use of text keywords. Specifically, many database systems support text indexes, and these could be used to satisfy certain XPaths. However, this technique can only satisfy a small subset of XPath queries. Thus, there have been no effective indexing techniques in existing database systems that can be used to handle a wide variety of XPath queries.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.


1. Field of the Invention
The present invention is related to a lithography system.
2. Background Art
In lithography systems, pattern generators are used to pattern substrates during an exposure process. Example lithography systems include, but are not limited to, reflective or transmissive maskless, immersion, and mask-based system. Example substrates include, but are not limited to, semiconductor wafers, flat panel display substrates, flexible substrates, and the like. Light interacting with an illumination spot on the pattern generator becomes patterned. The patterned light is projected using a projection optical system onto one or more target areas of the substrate during the exposure process to form features on a photosensitive material (e.g., a photoresist) on the substrate.
In some applications of the lithography system, it is desired to have double telecentric illumination, which means that a chief ray of an illumination beam is telecentric in both object space and image space. Object space is proximate an object plane, typically defined by the pattern generator. Image space is proximate an image plane, typically defined by the substrate. Conventional systems having double telecentric illumination generally use a transmissive optic to direct the illumination from an illuminator towards the pattern generator and from the pattern generator towards a projection optical system. However, transmissive optics tend to absorb illumination, and thus can have low efficiency. For example, a typical transmissive optic can sometimes transmit as little as about 20–25% of the light between the illuminator and the projection system. Also, transmissive optics can cause polarization, aberration, distortion, birefringence, and other errors in the illumination, which sometimes requires complex optics to correct.
Therefore, what is needed is a system and method that can be used to provide a double telecentric system, which eliminates or substantially reduces absorption of illumination and/or that eliminates or substantially reduces polarization change, birefringence, aberration, distortion, and/or other errors being introduced in the illumination beam.


Heretofore some kinds of 4-aryl-4-halopyrazolidine-3,5-dione derivatives have been known. For example, An. Quim. vol. 71, 396 to 399 (1975) discloses that compounds A, B and C to be described later, i.e. 4-aryl-4-halopyrazolidine-3,5-dione derivatives, can be prepared by Diels-Alder reaction between 4-chloro-4-phenylpyrazoline-3,5-dione and diene. Further An. Quim. vol. 75, 931 to 935 (1979) describes the under-mentioned compounds D and E as an intermediate for preparing 13,14-azasteroid, the compounds being prepared by Diels-Alder reaction between 4-chloro-4-phenylpyrazoline-3,5-dione and diene. In addition, Comment., Pontif. Acad. Sci. vol.2, 8 (1975) sets forth that compounds A, B and C to be described later can be prepared by chlorination of the corresponding 4-phenylpyrazolidine-3,5-dione derivative.
However, the compounds of the invention represented by the formula (1) are novel compounds which are not included in conventional compounds.
On the other hand, 4-aryl-4-nitropyrazolidine-3,5-dione derivatives are entirely novel compounds. ##STR2##
With insecticides and miticides in use for many years, pest insects have acquired resistance in recent years and become difficult to control with conventional insecticides. Accordingly it is expected to develop novel insecticides. Also in the herbicide field, the development of novel herbicides are expected.
An object of the present invention is to provide 4-aryl-4-substituted pyrazolidine-3,5-dione derivatives which have not only extremely high insecticidal and miticidal activities but a high herbicidal activity.


While many food containers have lids that snap or “lock” onto the container to retain the food inside the container (e.g., Tupperware® and VERSAtainer™), these containers do not secure the food from unauthorized access or tampering.
The issues of tampering and access have been addressed in the prior art with respect to bottles for medications and the like through the use of child-proof caps and single-use tamper-indicating rings, tabs, foils and the like, as well as locking medicine cabinets.
While medications have been determined to be worthy of such means for protection from tampering and access, the prior art has not considered meal dishes to be worthy of protection from tampering and unauthorized access.