A process for growing a crystalline thin film comprises forming a crystalline region comprising a single crystal-nucleus or crystal-grain at a predetermined position of an amorphous thin film, then implanting ions of at least one element constituting the amorphous thin film into a region other than the crystalline region and thereafter carrying out heat treatment to have the crystal-nucleus or crystal-grain grown along the plane direction of the amorphous thin film, thereby crystallizing the amorphous film by solid phase growth.

1. Field of the Invention
This invention relates to a process for growing a crystalline thin film to be used for electronic devices, optical devices, etc. of semiconductor integrated circuits. More particularly, it relates to a process for growing a crystalline thin film which can form the film at a relative lower temperature by controlling the nucleation positions of a plurality of thin film crystal grains, and can control also the position of the grain boundary and the sizes of crystal grains, etc.
2. Related Background Art
In the field of crystal formation technique which permits an amorphous thin film formed on a substrate having no crystallinity such as an amorphous substrate, etc. to grow in solid phase to a polycrystalline thin film by heat treatment at a temperature not higher than the melting point, there have been proposed some processes for making the grain sizes of the crystal grains constituting the polycrystalline thin film larger.
For example, there has been reported a crystal formation process, in which a polycrystalline Si thin film with fine grain sizes having a film thickness of about 1000.ANG. deposited by the LPCVD method on an amorphous SiO.sub.2 surface is made amorphous by implantation of Si.sup.+ ions, and then subjected to heat treatment in an N.sub.2 atmosphere at about 600 .degree. C., thereby making the above Si thin film as made amorphous a polycrystalline thin film with the maximum grain size of about 5 .mu.m (R. Reif and E. Knott, Electron. Lett. 17, 586 (1981)). Also in almost the same steps, by depositing the thin film previously in amorphous state and applying ion implantation thereinto, equal results are obtained (I. - W. Wu, A. Chiang, M. Fuse, L. Overcoglu and T. Y. Huang, J. Appl. Phys. 65, 4036 (1989)). Further, there is also a report that, by depositing the amorphous thin film previously at a further lower temperature, a polycrystalline thin film with grain sizes comparable to the foregoing two examples can be obtained without application of ion implantation.
When various electronic devices are formed on the polycrystalline thin films obtained by these processes, since the average grain size of the crystal grains is by far larger than conventional polycrystalline silicon, etc. as deposited by the LPCVD method, those with relatively higher performances can be obtained.
However, in these crystal formation processes, although the average grain size of the crystal grains of the thin film obtained are large, their grain size distribution and the position of the crystal grain boundary are not controlled. For, in this case, crystallization of the amorphous thin film takes place via the process in which crystal nuclei generated at random positions in the thin film grows along the plane direction while being restricted in growth in the film thickness direction to form flat crystal grains. Therefore the positions of the crystal grain boundaries formed at the contact points with the adjacent crystal grains are also randomly determined, whereby the grain sizes are distributed over a wide range. Accordingly, the following problems will ensue only if the average grain size of crystal grains is large. For example, when an MOS transistor is formed by use of the above polycrystalline film, if the average grain size becomes comparable with the size of channel, the situation becomes such that no grain boundary is included in the channel portion or that several or more boundaries are included. Crystal grain boundary will be a great obstacle against electroconduction, and therefore in the region where the number of grain boundaries included in the channel is 0 to several, the electrical characteristics will be greatly changed depending on the number of the grain boundaries included in the channel (N. Yamauchi, J. - J. J. Hajjar and R. Reif, IEDM 89-353 (1989)). For this reason, when an integrated circuits, etc. are formed, there occurs a great variance in the characteristics between a plurality of devices, which has been a remarkable obstacle in production of devices, etc.
Of the problems in the large grain size polycrystalline thin film by the solid phase crystallization as described above, the method of inhibiting variance of grain sizes is disclosed in Japanese Laid-Open Patent Application No. 58-56406. That method is described by referring to FIGS. 3A and 3B. First, as shown in FIG. 3A, on the surface of an amorphous Si thin film 12 formed on an amorphous substrate 11 are provided periodically thin film small strips 13 made of another material, followed by annealing of the substrate as a whole by a conventional heating furnace. Then, in the amorphous Si thin film 12, formation of crystal nuclei 14 will occur preferentially from the site in contact with the peripheral of the thin film small strip 13. Accordingly, by growing further the crystal nuclei, the amorphous Si thin film 12 will be crystallized over the whole region, whereby a polycrystalline thin film comprising the crystal grain groups 15 with large sizes as shown in FIG. 3B is obtained. Japanese Laid-Open Patent Application No. 58-56406 states that the variance of grain sizes can be reduced to about 1/3 as compared with the prior art method previously shown.
However, even such method is still unsatisfactory. For example, when thin film small strips 13 are arranged in lattice points with intervals of 10 .mu.m, the variance of grain sizes can be limited only to the range of 3 to 8 .mu.m. Further, the crystal grain boundary position is not easily controlled under the present situation. The reason is that due to the localization effect of elastic energy at the portion where the amorphous Si thin film 12 is in contact with the peripheral portion of the thin film small strip 13, preferential nucleation occurs around the thin film small strip 13, whereby a plurality of nuclei will be generated along the peripheral, and their number is difficult to control.
Concerning the method of controlling the nucleation position in the solid phase growth of amorphous Si thin film, Japanese Laid-Open Patent Application No. 63-253616, etc. discloses other proposals. According to the method disclosed in the publication, as shown in FIG. 4, regions 23 are provided by implanting N.sup.+ ions locally into the amorphous Si thin film 22 in the direction shown by the arrowhead A in the figure, and crystal nuclei are generated preferentially from the portions other than the regions 23. In the figure, 21 designates an amorphous substrate.
Further, for inhibiting variance of crystal grain sizes by arranging regularly the crystal grains having larger sizes and controlling the grain boundary positions, not only the regions where crystal nuclei are preferentially formed should be provided within the plane of the amorphous thin film, but at the same time in the areas around those regions, spontaneous nucleation must be inhibited while ensuring sufficient crystal growth rate. For example, in the method of Japanese Laid-Open Patent Application No. 58-56406, even if only a single crystal-nucleus may happen to be formed around the thin film small strip 13, if random nucleation has occurred in the film until it has reached 8 .mu.m at the maximum as the grain size, its growth will be inhibited, whereby growth to a crystal grain with larger grain size than that is very difficult.
As described above, so many problems to be overcome have existed in the techniques proposed in the prior art.

Process for growing crystalline thin film


A sheet-material transporting device including a separation roller which is rotated in a predetermined direction; and a retarding member having an opposing surface opposing the separation roller, and forming a sheet-material transport passage between the opposing surface and the separation roller. The device is provided with a pressing member disposed in the opposing surface. The pressing member has a pressing surface which projects from the opposing surface and has a coefficient of friction smaller than that of the opposing surface. The pressing surface of the pressing member is caused to retract from its projecting position in correspondence with the thickness of the sheet material inserted into the transport passage. Accordingly, if, for example, two sheets are inserted in a superposed state into the transport passage, the pressing surface is caused to retract by a large amount. Hence, the sheet located on the opposing surface side is brought into contact with the opposing surface, and the transport thereof is hampered. At the same time, only the sheet located on the separation roller side slips over the sheet located on the opposing surface side and is transported by means of the rotational force of the separation roller.

1. Field of the Invention
The present invention relates to an automatic sheet-materal feeder, and more particularly to a sheet-material transporting device adapted to prevent a state in which a plurality of ultra thin sheets of paper are fed in a superposed or overlapping state (hereafter feeding in this state will be referred to as the overlapped feeding), as well as an automatic sheet-material feeder equipped with the sheet-material transporting device.
2. Description of the Related Art
A conventional automatic sheet-material feeder is shown in FIG. 13. In this apparatus, a retarding member 74 is disposed such that an opposing surface 72 thereof is located in proximity to an outer peripheral surface of a separation roller 70, which is rotated by an unillustrated driving means, and in such a manner as to extend in the axial direction of the separation roller 70 (i.e., in a direction perpendicular to the plane of the drawing of FIG. 13). A paper guide 76 extending in the axial direction of the separation roller 70 is attached to a side of the retarding member 74 to which the leading end of each document 56 placed on a hopper 78 is fed.
The hopper 78 in which the documents 56 are placed is moved by an unillustrated transfer mechanism to a position at which an uppermost one of the documents 56 is nipped by the paper guide 76 and the separation roller 70. As the separation roller 70 rotates, the uppermost one of the documents 56 is fed by a frictional force through the rotation of the separation roller 70, and is supplied to an unillustrated rotary camera for microfilm photographing, or the like.
In this case, the overlapped feeding of the documents 56 is prevented by adjusting a gap between the outer peripheral surface of the separation roller 70 and the opposing surface 72 of the retarding member 74, an angle at which the retarding member 74 is disposed, and an angle at which the document 56 is fed into a nip between the retarding member 74 and the separation roller 70.
According to the above-described prior art, however, in a case where the documents 56 of varying thicknesses or the documents 56 of different paper quality (e.g. in the coefficient of friction) are present in a mixed form, it is difficult to properly set the aforementioned gap and the like, so that the overlapped feeding of the documents 56 is unavoidable.
In addition, if a leading (inserting-side) end of the document 56, i.e., the retarding member 74-side end thereof, becomes deformed and corrugated, as shown in FIG. 14, there is the problem that trough portions 56A abut against a bent portion 76A of the paper guide 76, with the result that buckling occurs. In addition, if buckling occurs in this manner, the document 56 is jammed between the retarding member 74 and the separation roller 70, or the document 56 is wrapped around the separation roller 70, thereby making it impossible to transport the documents 56.

Sheet-material transporting device and automatic sheet-material feeder


The present disclosure provides a method for aligning a master oscillator power amplifier (MOPA) system. The method includes ramping up a pumping power input into a laser amplifier chain of the MOPA system until the pumping power input reaches an operational pumping power input level; adjusting a seed laser power output of a seed laser of the MOPA system until the seed laser power output is at a first level below an operational seed laser power output level; and performing a first optical alignment process to the MOPA system while the pumping power input is at the operational pumping power input level, the seed laser power output is at the first level, and the MOPA system reaches a steady operational thermal state.

The electronics industry has experienced an ever increasing demand for smaller and faster electronic devices which are simultaneously able to support a greater number of increasingly complex and sophisticated functions. Accordingly, there is a continuing trend in the semiconductor industry to manufacture low-cost, high-performance, and low-power integrated circuits (ICs). Thus far these goals have been achieved in large part by scaling down semiconductor IC dimensions (e.g., minimum feature size) and thereby improving production efficiency and lowering associated costs. However, such scaling has also introduced increased complexity to the semiconductor manufacturing process. Thus, the realization of continued advances in semiconductor ICs and devices calls for similar advances in semiconductor manufacturing processes and technology.
For example, semiconductor lithography processes may use lithographic templates (e.g., photomasks or reticles) to optically transfer patterns onto a substrate. Such a process may be accomplished by projection of a radiation source, through an intervening photomask or reticle, onto the substrate having a photosensitive material (e.g., photoresist) coating. The minimum feature size that may be patterned by way of such a lithography process is limited by the wavelength of the projected radiation source. In view of this, extreme ultraviolet (EUV) light sources and lithographic processes have been introduced.
One of the methods to generate EUV radiation involves use of a high-power laser source such as a master oscillator power amplifier system (MOPA). A MOPA system includes a seed laser as a master oscillator and several power amplifiers including high gain preamplifiers as pre-amplifier and high efficiency power amplifiers as power amplifiers. In order to achieve the maximum output power, a MOPA for EUV generation requires alignment to provide focused laser pulses. Due to the limited optical efficiency of the power amplifiers, a large amount of energy input into the amplifiers become heat that can change the refractive index of all gaseous and solid medium through which the laser radiation passes, resulting in a phenomenon commonly referred to as "thermal lensing." Thermal lensing causes the laser beam from the MOPA system to drift, giving rise to reduction of laser power output and safety issues. Therefore, there is a great deal of interests in methods and systems for efficiently and safely align MOPA systems.

Methods and systems for aligning master oscillator power amplifier systems

TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD.


A sound, a video and/or other environments are proposed in tune with the physical condition of a user and a peripheral environmental condition such that it becomes possible for users to feel comfortable and to be satisfied with their sensibility. It is designed to produce an objective sound, video and/or other environments by inputting bio-information of a user such as breathing, pulse-beats and heartbeats or environment information such as weather, date and hour and ambient temperature, by comparing information with the accumulated information utilized in the past, or by setting a condition that the user desires.

1. Field of the Invention
The present invention relates, for example, to a control apparatus for controlling a condition of a user and a periphery environment by using bio-information of a user such as breathing, pulse-beats and heartbeats and environment information such as weather, date and hour and ambient temperature and further relates to its control method.
2. Description of the Related Art
Heretofore, it has been known an audio system, a television, a video apparatus and the like as an acoustic and a video apparatus. These and reproduce information recorded on a recording medium beforehand and also receive and reproduce information distributed by means of an electric wave and the like, but in any of them, users themselves should select a desired sound and/or video content and the reproducing condition of the sound volume, the sound quality, the brightness of the video and the like was to be adjusted when it is necessary.
In recent years, an environment adaptive type acoustic apparatus has been proposed where music can be enjoyed pleasantly by detecting bio-information of a resident even though an aged person and a physically handicapped person resides in any part of a room. According to this apparatus, it is controlled such that the condition becomes the most optimal one fit with this physical condition of a resident by properly adjusting the sound quality, the volume of the sound or the like according to the bio-information of a resident. Also, it is possible to reproduce preferable music of a resident corresponding to his physical condition by judging what a content the resident listens to preferably in what a situation according to the physical condition of the resident and at the same time according to the living environment condition, for example, such as date and hour, weather and a number of indoor people.
In a patent reference 1, there is shown with respect to an environment adaptive type acoustic apparatus mentioned above.
<Patent Reference 1>
Japanese Laid-open Patent No. 11-221196
However, in the prior art an environment adaptive type acoustic apparatus mentioned above, it is possible to propose music suitable for a present physical condition of a user, but there was a problem that it was not consider about a condition which a user feels comfortable and the degree of his satisfaction. For example, it was not possible to make a user be a relaxed state of mind by easing his tension in a case when a user is in a state of tension before going to bed or make his physical condition be activated in a case when an activity level of a user is low in the morning. Therefore, the sensibility of a user could not be satisfied as a result.

Control apparatus and method for controlling an environment based on bio-information and environment information


Providing a sighting device having a simple structure, being easy to manufacture and free from parallax. A sighting device comprises, in order from a target object side, a positive meniscus lens having a convex surface facing the target object and a negative meniscus lens having a convex surface facing the target object, wherein the surface of said positive meniscus lens that faces away from said target object or the surface of said negative meniscus lens that faces toward said target object is adapted to constitute a semi-transparent reflection surface or a wavelength selective reflection surface, and a point source is provided at a focal point of a catadioptric optical system constituted by said semi-transparent reflection surface or said wavelength selective reflection surface and a refracting surface of the negative meniscus lens having with the convex surface facing said target object, the refracting surface facing away from said target object side.

Sighting devices having a built-in point source have conventionally been known. For example, there is a known sighting device in which a semi-transparent concave mirror is provided in the interior thereof and a point source is provided at the focal point of the concave mirror to deliver parallel reflected light to a viewer's eye while allowing light from a target object to be transmitted as it is without being refracted to deliver it to the viewer's eye. In this sighting device, a person who sees though the sighting device will aim while observing a target object and a point image that suggests the point of impact in an overlapping manner. In this case, if the reflected light is not parallel or the transmitted light is refracted, parallax will occur when there is a misalignment between the optical axis of the viewer's eye and the optical axis of the sighting device, which will make precise sighting impossible. In view of this, to prevent such a disadvantage, the concave mirror is designed to be a paraboloidal, and the opposite convex surface is designed to be ellipsoidal or hyperboloidal (see, for example, Japanese Patent Application Laid-Open No. 7-56088).
The above described prior art suffers from a problem that manufacturing thereof is difficult since use is made of a sophisticated aspherical surface that is introduced to achieve a sighting device that is free from parallax.


An apparatus and method for forming and bonding skins to shaped articles includes a first sleeve having an open top end and a lower end closed by a bottom plate, a second sleeve having an open top end and a lower second end which is slidable arranged, and coaxially connected, with the top end of the first sleeve, a top plate, and a forming medium. The forming medium may be an elastic medium, a fluid, or a plurality of low-friction particles, and may be covered by a flexible open pore sponge blanket. The shaped article and the laminate skin to be bonded thereto are placed on the forming medium within a space defined in part by the second sleeve, and the forming medium is pressurized so as to cause the skin to form and bond to the shaped article.

The invention relates to a method and apparatus for forming and bonding decorative skins such as wood veneers and metal foils, as well as synthetic and natural laminates, over shaped articles. According to the prior art, this is achieved by one of three methods. The first method, "profile wrapping", uses a number of rollers which roll the skins onto the shaped article. However, this method is undesirable since the physical details of the shaped article over which the skin is formed are limited depending upon the diameter of the rollers. In addition, this type of equipment is extremely expensive and service intensive.
The second type of prior art method involves the use of a membrane press. In this method, a rubber sheet is stretched over the mouth of a high pressure press. After the press is closed, a gas chamber behind the rubber sheet is pressurized with air, water, or oil, thus forcing the membrane to form to the shape of the shaped article. Although this method allows the laminate to conform to smaller details of the shaped article than possible with profile wrapping, this method is limited to a maximum pressure of around 10 bars. In addition, the membrane press is a very dangerous piece of equipment since the rubber sheet can potentially rupture if the pressure in the gas chamber exceeds the closing power of the press, or if the shaped article has sharp corners. When hot oil is used in the device, the prospect of rupture of the rubber membrane is especially dangerous.
The third type of prior art method involves the use of a piston type pressure chamber. In this method, a piston pushes the article and decorative skin laminate into a forming-medium. The forming-medium then forces the laminate onto the article. Although this method is successful, the charging of the chamber and the pressurizing of the piston are complicated and slow. Further, the steps of heating and cooling the decorative laminate in the chamber are time consuming and energy intensive.

Expanding pressure chamber for bonding skins to flat and shaped articles


A control system configured to control an internal combustion engine includes a crankshaft and an engine speed sensor. The crankshaft is rotated in response to combusting a mixture of air and fuel delivered to at least one cylinder included in the internal combustion engine. The engine output speed sensor is configured to output an engine output speed signal indicating a rotational speed of the crankshaft. An engine control module controls an amount of air and fuel delivered to the at least one cylinder and estimates a torque output based on the amount of air and fuel. A torque compensation module is configured to determine at least one weak cylinder based on the engine output speed signal. The torque compensation module is further configured to determine a torque compensation value that adjusts the estimated torque output based on the weak cylinder.

A vehicle includes an engine that generates torque. The engine transfers the torque output to a transmission via a crankshaft. The vehicle moves when torque output is transferred to one or more wheels of the vehicle. A crankshaft sensor or engine output speed (EOS) sensor generates a signal based upon the rotation of the crankshaft.
On occasion the engine may misfire due to various reasons such as, for example, improper delivery of fuel and/or air. Conventional engine control systems utilize the torque output generated by the engine to detect an engine misfire. In some instances, an engine misfire causes one or more individual cylinders to output an unequal amount of drive torque. That is to say, the strength of some cylinders can be weaker than others, resulting in a torque imbalance across the cylinders. Consequently, an engine misfire may be misdiagnosed.


A first electrophoretic medium comprises an electrically charged particle suspended in a suspending fluid, the particle having a polymeric shell having repeating units derived from at least one monomer the homopolymer of which is incompatible with the suspending fluid. A second, similar electrophoretic medium comprises a suspending fluid, and first and second types of electrically charged particle suspended in the suspending fluid, the two types of particle having differing optical characteristics but both having polymeric shells. The polymeric shells are arranged such that homoaggregation of the two types of particles is thermodynamically favored over heteroaggregation.

The present invention relates to electrophoretic media. The present media are especially, although not exclusively, intended for use in encapsulated and microcell electrophoretic displays. The invention also relates to electrophoretic particles for use in such media, and to displays incorporating such media. Certain aspects of the present invention extend to electro-optic displays other than electrophoretic displays. The electrophoretic particles of the present invention are modified with polymers. The electro-optic displays of the present invention use an electro-optic medium having a voltage threshold.
In the displays of the present invention, the electro-optic medium (when a non-electrophoretic electro-optic medium) will typically be a solid (such displays may hereinafter for convenience be referred to as "solid electro-optic displays"), in the sense that the electro-optic medium has solid external surfaces, although the medium may, and often does, have internal liquid- or gas-filled spaces, and to methods for assembling displays using such an electro-optic medium. Thus, the term "solid electro-optic displays" includes encapsulated electrophoretic displays, encapsulated liquid crystal displays, and other types of displays discussed below.
The term "electro-optic", as applied to a material or a display, is used herein in its conventional meaning in the imaging art to refer to a material having first and second display states differing in at least one optical property, the material being changed from its first to its second display state by application of an electric field to the material. Although the optical property is typically color perceptible to the human eye, it may be another optical property, such as optical transmission, reflectance, luminescence or, in the case of displays intended for machine reading, pseudo-color in the sense of a change in reflectance of electromagnetic wavelengths outside the visible range.
The term "gray state" is used herein in its conventional meaning in the imaging art to refer to a state intermediate two extreme optical states of a pixel, and does not necessarily imply a black-white transition between these two extreme states. For example, several of the patents and published applications referred to below describe electrophoretic displays in which the extreme states are white and deep blue, so that an intermediate "gray state" would actually be pale blue. Indeed, as already mentioned the transition between the two extreme states may not be a color change at all.
The terms "bistable" and "bistability" are used herein in their conventional meaning in the art to refer to displays comprising display elements having first and second display states differing in at least one optical property, and such that after any given element has been driven, by means of an addressing pulse of finite duration, to assume either its first or second display state, after the addressing pulse has terminated, that state will persist for at least several times, for example at least four times, the minimum duration of the addressing pulse required to change the state of the display element. It is shown in published U.S. Patent Application No. 2002/0180687 that some particle-based electrophoretic displays capable of gray scale are stable not only in their extreme black and white states but also in their intermediate gray states, and the same is true of some other types of electro-optic displays. This type of display is properly called "multi-stable" rather than bistable, although for convenience the term "bistable" may be used herein to cover both bistable and multi-stable displays.
Several types of electro-optic displays are known. One type of electro-optic display is a rotating bichromal member type as described, for example, in U.S. Pat. Nos. 5,808,783; 5,777,782; 5,760,761; 6,054,071 6,055,091; 6,097,531; 6,128,124; 6,137,467; and 6,147,791 (although this type of display is often referred to as a "rotating bichromal ball" display, the term "rotating bichromal member" is preferred as more accurate since in some of the patents mentioned above the rotating members are not spherical). Such a display uses a large number of small bodies (typically spherical or cylindrical) which have two or more sections with differing optical characteristics, and an internal dipole. These bodies are suspended within liquid-filled vacuoles within a matrix, the vacuoles being filled with liquid so that the bodies are free to rotate. The appearance of the display is changed to applying an electric field thereto, thus rotating the bodies to various positions and varying which of the sections of the bodies is seen through a viewing surface. This type of electro-optic medium is typically bistable.
Another type of electro-optic display uses an electrochromic medium, for example an electrochromic medium in the form of a nanochromic film comprising an electrode formed at least in part from a semi-conducting metal oxide and a plurality of dye molecules capable of reversible color change attached to the electrode; see, for example O'Regan, B., et al., Nature 1991, 353, 737; and Wood, D., Information Display, 18(3), 24 (March 2002). See also Bach, U., et al., Adv. Mater., 2002, 14(11), 845. Nanochromic films of this type are also described, for example, in U.S. Pat. No. 6,301,038, International Application Publication No. WO 01/27690, and in U.S. Patent Application 2003/0214695. This type of medium is also typically bistable.
Another type of electro-optic display, which has been the subject of intense research and development for a number of years, is the particle-based electrophoretic display, in which a plurality of charged particles move through a suspending fluid under the influence of an electric field. Electrophoretic displays can have attributes of good brightness and contrast, wide viewing angles, state bistability, and low power consumption when compared with liquid crystal displays. Nevertheless, problems with the long-term image quality of these displays have prevented their widespread usage. For example, particles that make up electrophoretic displays tend to settle, resulting in inadequate service-life for these displays.
Numerous patents and applications assigned to or in the names of the Massachusetts Institute of Technology (MIT) and E Ink Corporation have recently been published describing encapsulated electrophoretic media. Such encapsulated media comprise numerous small capsules, each of which itself comprises an internal phase containing electrophoretically-mobile particles suspended in a liquid suspending medium, and a capsule wall surrounding the internal phase. Typically, the capsules are themselves held within a polymeric binder to form a coherent layer positioned between two electrodes. Encapsulated media of this type are described, for example, in U.S. Pat. Nos. 5,930,026; 5,961,804; 6,017,584; 6,067,185; 6,118,426; 6,120,588; 6,120,839; 6,124,851; 6,130,773; 6,130,774; 6,172,798; 6,177,921; 6,232,950; 6,249,721; 6,252,564; 6,262,706; 6,262,833; 6,300,932; 6,312,304; 6,312,971; 6,323,989; 6,327,072; 6,376,828; 6,377,387; 6,392,785; 6,392,786; 6,413,790; 6,422,687; 6,445,374; 6,445,489; 6,459,418; 6,473,072; 6,480,182; 6,498,114; 6,504,524; 6,506,438; 6,512,354; 6,515,649; 6,518,949; 6,521,489; 6,531,997; 6,535,197; 6,538,801; 6,545,291; 6,580,545; 6,639,578; 6,652,075; 6,657,772; 6,664,944; 6,680,725; 6,683,333; 6,704,133; 6,710,540; 6,721,083; 6,727,881; 6,738,050; 6,750,473; and 6,753,999; and U.S. Patent Applications Publication Nos. 2002/0019081; 2002/0021270; 2002/0060321; 2002/0060321; 2002/0063661; 2002/0090980; 2002/0113770; 2002/0130832; 2002/0131147; 2002/0171910; 2002/0180687; 2002/0180688; 2002/0185378; 2003/0011560; 2003/0020844; 2003/0025855; 2003/0038755; 2003/0053189; 2003/0102858; 2003/0132908; 2003/0137521; 2003/0137717; 2003/0151702; 2003/0214695; 2003/0214697; 2003/0222315; 2004/0008398; 2004/0012839; 2004/0014265; 2004/0027327; 2004/0075634; 2004/0094422; 2004/0105036; 2004/0112750; and 2004/0119681; and International Applications Publication Nos. WO 99/67678; WO 00/05704; WO 00/38000; WO 00/38001; WO00/36560; WO 00/67110; WO 00/67327; WO 01/07961; WO 01/08241; WO 03/107,315; WO 2004/023195; and WO 2004/049045.
Known electrophoretic media, both encapsulated and unencapsulated, can be divided into two main types, referred to hereinafter for convenience as "single particle" and "dual particle" respectively. A single particle medium has only a single type of electrophoretic particle suspended in a suspending medium, at least one optical characteristic of which differs from that of the particles. (In referring to a single type of particle, we do not imply that all particles of the type are absolutely identical. For example, provided that all particles of the type possess a charge of the same polarity, considerable variation in parameters such as particle color, size and electrophoretic mobility can be tolerated without affecting the utility of the medium. For example, two particles of different color, but the same charge, may be mixed in a single capsule, together with a single pigment (or multiple pigments) of opposite charge, to provide, by appropriate choice of the colors of these pigments, colors of any desired intermediate shade in either or both of the optical states.) When such a medium is placed between a pair of electrodes, at least one of which is transparent, depending upon the relative potentials of the two electrodes, the medium can display the optical characteristic of the particles (when the particles are adjacent the electrode closer to the observer, hereinafter called the "front" electrode) or the optical characteristic of the suspending medium (when the particles are adjacent the electrode remote from the observer, hereinafter called the "rear" electrode (so that the particles are hidden by the suspending medium).
A dual particle medium has two different types of particles differing in at least one optical characteristic and a suspending fluid which may be uncolored or colored, but which is typically uncolored. The two types of particles differ in electrophoretic mobility; this difference in mobility may be in polarity (this type may hereinafter be referred to as an "opposite charge dual particle" medium) and/or magnitude. When such a dual particle medium is placed between the aforementioned pair of electrodes, depending upon the relative potentials of the two electrodes, the medium can display the optical characteristic of either set of particles, although the exact manner in which this is achieved differs depending upon whether the difference in mobility is in polarity or only in magnitude. For ease of illustration, consider an electrophoretic medium in which one type of particles is black and the other type white. If the two types of particles differ in polarity (if, for example, the black particles are positively charged and the white particles negatively charged), the particles will be attracted to the two different electrodes, so that if, for example, the front electrode is negative relative to the rear electrode, the black particles will be attracted to the front electrode and the white particles to the rear electrode, so that the medium will appear black to the observer. Conversely, if the front electrode is positive relative to the rear electrode, the white particles will be attracted to the front electrode and the black particles to the rear electrode, so that the medium will appear white to the observer.
If the two types of particles have charges of the same polarity, but differ in electrophoretic mobility (this type of medium may hereinafter to referred to as a "same polarity dual particle" medium), both types of particles will be attracted to the same electrode, but one type will reach the electrode before the other, so that the type facing the observer differs depending upon the electrode to which the particles are attracted. For example suppose the previous illustration is modified so that both the black and white particles are positively charged, but the black particles have the higher electrophoretic mobility. If now the front electrode is negative relative to the rear electrode, both the black and white particles will be attracted to the front electrode, but the black particles, because of their higher mobility will reach it first, so that a layer of black particles will coat the front electrode and the medium will appear black to the observer. Conversely, if the front electrode is positive relative to the rear electrode, both the black and white particles will be attracted to the rear electrode, but the black particles, because of their higher mobility will reach it first, so that a layer of black particles will coat the rear electrode, leaving a layer of white particles remote from the rear electrode and facing the observer, so that the medium will appear white to the observer: note that this type of dual particle medium requires that the suspending fluid be sufficiently transparent to allow the layer of white particles remote from the rear electrode to be readily visible to the observer. Typically, the suspending fluid in such a display is not colored at all, but some color may be incorporated for the purpose of correcting any undesirable tint in the white particles seen therethrough, or to produce a desirable shade of color in the gray state.
Both single and dual particle electrophoretic displays may be capable of intermediate gray states having optical characteristics intermediate the two extreme optical states already described.
Some of the aforementioned patents and published applications disclose encapsulated electrophoretic media having three or more different types of particles within each capsule. For purposes of the present application, such multi-particle media are regarded as sub-species of dual particle media.
Also, many of the aforementioned patents and applications recognize that the walls surrounding the discrete microcapsules in an encapsulated electrophoretic medium could be replaced by a continuous phase, thus producing a so-called polymer-dispersed electrophoretic display, in which the electrophoretic medium comprises a plurality of discrete droplets of an electrophoretic fluid and a continuous phase of a polymeric material, and that the discrete droplets of electrophoretic fluid within such a polymer-dispersed electrophoretic display may be regarded as capsules or microcapsules even though no discrete capsule membrane is associated with each individual droplet; see for example, the aforementioned 2002/0131147. Accordingly, for purposes of the present application, such polymer-dispersed electrophoretic media are regarded as sub-species of encapsulated electrophoretic media.
A related type of electrophoretic display is a so-called "microcell electrophoretic display". In a microcell electrophoretic display, the charged particles and the suspending fluid are not encapsulated within microcapsules but instead are retained within a plurality of cavities formed within a carrier medium, typically a polymeric film. See, for example, International Application Publication No. WO 02/01281, and published US Application No. 2002/0075556, both assigned to Sipix Imaging, Inc.
Although electrophoretic media are often opaque (since, for example, in many electrophoretic media, the particles substantially block transmission of visible light through the display) and operate in a reflective mode, many electrophoretic displays can be made to operate in a so-called "shutter mode" in which one display state is substantially opaque and one is light-transmissive. See, for example, the aforementioned U.S. Pat. Nos. 6,130,774 and 6,172,798, and U.S. Pat. Nos. 5,872,552; 6,144,361; 6,271,823; 6,225,971; and 6,184,856. Dielectrophoretic displays, which are similar to electrophoretic displays but rely upon variations in electric field strength, can operate in a similar mode; see U.S. Pat. No. 4,418,346.
An encapsulated or microcell electrophoretic display typically does not suffer from the clustering and settling failure mode of traditional electrophoretic devices and provides further advantages, such as the ability to print or coat the display on a wide variety of flexible and rigid substrates. (Use of the word "printing" is intended to include all forms of printing and coating, including, but without limitation: pre-metered coatings such as patch die coating, slot or extrusion coating, slide or cascade coating, curtain coating; roll coating such as knife over roll coating, forward and reverse roll coating; gravure coating; dip coating; spray coating; meniscus coating; spin coating; brush coating; air knife coating; silk screen printing processes; electrostatic printing processes; thermal printing processes; inkjet printing processes; and other similar techniques.) Thus, the resulting display can be flexible. Further, because the display medium can be printed (using a variety of methods), the display itself can be made inexpensively.
However, the service life of encapsulated electrophoretic displays, of both the single and dual particle types, is still lower than is altogether desirable. It appears (although this invention is in no way limited by any theory as to such matters) that this service life is limited by factors such as sticking of the electrophoretic particles to the capsule wall, and the tendency of particles to aggregate into clusters which prevent the particles completing the movements necessary for switching of the display between its optical states. In this regard, opposite charge dual particle electrophoretic displays pose a particularly difficult problem, since inherently oppositely charged particles in close proximity to one another will be electrostatically attracted to each other and will display a strong tendency to form stable aggregates. Experimentally, it has been found that if one attempts to produce a black/white encapsulated display of this type using untreated commercially available titania and carbon black pigments, the display either does not switch at all or has a service life so short as to be undesirable for commercial purposes.
It has long been known that the physical properties and surface characteristics of electrophoretic particles can be modified by adsorbing various materials on to the surfaces of the particles, or chemically bonding various materials to these surfaces. For example, U.S. Pat. No. 4,285,801 (Chiang) describes an electrophoretic display composition in which the particles are coated with a highly fluorinated polymer, which acts as a dispersant, and which is stated to prevent the particles from flocculating and to increase their electrophoretic sensitivity. U.S. Pat. No. 4,298,448 (Müller et al.) describes an electrophoretic medium in which the particles are coated with an organic material, such as a wax, which is solid at the operating temperature of the medium but which melts at a higher temperature. The coating serves to lower the density of the electrophoretic particles and is also stated to increase the uniformity of the charges thereon. U.S. Pat. No. 4,891,245 describes a process for producing particles for use in electrophoretic displays, wherein a heavy, solid pigment, preferred for its high contrast or refractive index properties, is coated with a polymeric material. This process significantly reduces the specific density of the resultant particle, and is stated to create particles with smooth polymer surfaces that can be chosen for stability in a given electrophoretic carrier fluid, and possess acceptable electrophoretic characteristics. U.S. Pat. No. 4,680,103 (Beilin Solomon I et al.) describes a single particle electrophoretic display using inorganic pigment particles coated with an organosilane derivative containing quaternary ammonium groups; this coating is stated to provide quick release of the particles from the electrode adjacent the observer and resistance to agglomeration.
Later, it was found that simple coating of the electrophoretic particles with the modifying material was not entirely satisfactory since a change in operating conditions might cause part or all of the modifying material to leave the surface of the particles, thereby causing undesirable changes in the electrophoretic properties of the particles; the modifying material might possibly deposit on other surfaces within the electrophoretic display, which could give rise to further problems. Accordingly, techniques have been developed for securing the modifying material to the surface of the particles.
For example, U.S. Pat. No. 5,783,614 (Chen et al.) describes an electrophoretic display using diarylide yellow pigment particles modified with a polymer of pentafluorostyrene. The modified particles are produced by forming a mixture of the unmodified particles, the pentafluorostyrene monomer and a free radical initiator, and heating and agitating this mixture so that the monomer polymerizes in situ on the surface of the particles.
U.S. Pat. No. 5,914,806 (Gordon II et al.) describes electrophoretic particles formed by reacting pigment particles with a pre-formed polymer so that the polymer becomes covalently bonded to the surface of the particles. This process is of course restricted to pigments and polymers having chemical properties which allow the necessary reaction to form the covalent bond. Furthermore, a polymer with only a few sites capable of reacting with the particle material has difficulty in reacting with the solid interface at the particle surface; this can be due to polymer chain conformation in solution, steric congestion at the particle surface, or slow reactions between the polymer and the surface. Often, these problems restrict such reactions to short polymer chains, and such short chains typically only have a small effect on particle stability in electrophoretic media.
It is also known to use, in electrophoretic displays, particles consisting essentially of polymer; if dark colored particles are required, the polymer particles can be stained with a heavy metal oxide. See, for example, U.S. Pat. Nos. 5,360,689; 5,498,674; and 6,117,368. Although forming the electrophoretic particles from a polymer allows close control over the chemical composition of the particles, such polymer particles usually have much lower opacity than particles formed from inorganic pigments.
The aforementioned 2002/0185378 describes the advantages of using, in electrophoretic media, pigment particles which have polymer chemically bonded to, or cross-linked about, the pigment particles. This application also describes various improvements in such polymer-coated particles, including controlling the amount of polymer deposited on the particle, the structure of the polymer, techniques for forming the polymeric coating on the electrophoretic particles, and techniques for pretreatment of the electrophoretic particles before the formation of polymer coatings thereon. The application also describes a process for producing such a polymer-coated pigment particle, this process comprising: (a) reacting the pigment particle with a reagent having a functional group capable of reacting with, and bonding to, the particle, and also having a polymerizable or polymerization-initiating group, thereby causing the functional group to react with the particle surface and attach the polymerizable group thereto; and (b) reacting the product of step (a) with at least one monomer or oligomer under conditions effective to cause reaction between the polymerizable or polymerization-initiating group on the particle and the at least one monomer or oligomer, thereby causing the formation of polymer bonded to the pigment particle.
The aforementioned 2002/0180687 describes an electrophoretic medium comprising a plurality of particles suspended in a hydrocarbon suspending fluid, the particles being capable of moving through the fluid upon application of an electric field to the medium, the fluid having dissolved or dispersed therein a polyisobutylene having a viscosity average molecular weight in the range of about 400,000 to 1,200,000 g/mole, the polyisobutylene comprising from about 0.25 to about 2.5 percent by weight of the suspending fluid. The same application also describes an electrophoretic medium comprising a plurality of particles suspended in a suspending fluid, the particles being capable of moving through the fluid upon application of an electric field to the medium, the fluid having dissolved or dispersed therein a polymer having an intrinsic viscosity of η in the suspending fluid and being substantially free from ionic or ionizable groups in the suspending fluid, the polymer being present in the suspending fluid in a concentration of from about 0.5 [η]−1 to about 2.0 [η]−1. The presence of the polyisobutylene (PIB) or other polymer in the suspending fluid substantially increases the bistability of the display.
As already indicated, electrophoretic displays require only low electrical power to switch from one state to another. For a bistable display, this low power requirement for switching translates directly into a low overall power requirement for operation of the display. However, electrophoretic displays do not have unlimited image stability. Brownian diffusion and gravitational settling of the pigment particles, together with motion driven by small residual voltages induced by the applied switching pulse and other factors, all can degrade the optical state achieved by switching of the display. In cases where there is no mechanism to prevent this kind of optical state decay, the optical state must be periodically refreshed. Refreshing the display consumes power, and thus diminishes the utility of the display. In addition, in certain applications (active matrix driven displays in particular) it is difficult or impossible to accomplish the refreshing of a single pixel without a blanking pulse (i.e., a pulse which drives the pixel to one of its extreme optical states before it is driven to the final desired optical state cf. the aforementioned 2003/0137521. For these reasons, improvements in the image stability of electrophoretic media are still highly desirable.
Also as already discussed, the aforementioned 2002/0180687 describes electrophoretic media which achieve good image stability by incorporation of a high molecular weight polymer, for example PIB, that has good solubility in the suspending medium (typically an aliphatic hydrocarbon such as Isopar G) but which is not absorbed on the electrophoretic particles. The presence of this polymer in solution is believed (although the present invention is in no way limited by this belief) to induce a weak flocculation of the pigments by a mechanism known in the colloid science art as "depletion flocculation". Polymers other than PIB can be used for the same purpose. An example of a second polymer that has been shown to be useful for this purpose is Kraton G, a block copolymer comprising a polystyrene block and a hydrogenated polyisobutylene block, that forms aggregate structures in the suspending medium. In this case, the aggregates are the species that induce the depletion flocculation, rather than the monomeric block copolymer itself.
No matter what polymer is used to induce depletion, the incorporation of soluble, high molecular weight materials into the suspending medium will increase the viscosity of that medium. Since the response time of the display (the time needed at a given operating voltage to change the display, or any given pixel thereof, between its two extreme optical states) is proportional to the viscosity of the medium, the switching speed of the display will be reduced by this approach to image stability. Furthermore, since the depletion flocculation mechanism is only active at concentrations of polymer above the overlap concentration (which can be operationally defined as the concentration of polymer that causes the viscosity of the medium to increase by a factor of two), all polymers that act by this mechanism can be expected to produce a similar diminution of the switching speed. In practice, the switching speed is reduced by approximately a factor of two to three when enough polymer is used to give adequate image stability. It is desirable to have other means of achieving image stability that do not suffer from this tradeoff with response time.
As discussed above, PIB and other polymers improve image stability by manipulating the colloidal stability of the pigment particles. The preferred polymer coated particles described in the aforementioned 2002/0185378 are colloidally stable in the suspending medium because of a polymer shell of (typically) poly(lauryl methacrylate) that is grown on the surface of the particles during their preparation. By appropriate manipulation of the composition of the polymer shell, it is possible in principle to make particles with the same degree of colloidal stability (and hence displays with the same image stability) as that afforded by PIB, Kraton, and other polymers dispersed in the suspending medium but without requiring addenda like PIB in the suspending medium. Such displays should be substantially faster than displays that contain PIB, or equivalently, should operate at equivalent speed at lower applied voltage.
In one aspect, this invention seeks to provide approaches to providing electrophoretic particles with modified polymer shells that allow the production of fast, image-stable displays.
In other aspect, this invention seeks to provide an improved form of the two-step process for preparing such polymer-coated electrophoretic particles described in Paragraph 29 above. In preferred forms of this process, titania (or a similar metal oxide pigment) is first coated with silica, and the silica-coated titania is treated with a silane containing an ethylenic group. The resultant silane-treated titania may then be reacted with a variety of unsaturated monomers, for example, 2-ethylhexyl acrylate or lauryl methacrylate, in the presence of a free-radical polymerization initiator, to form the desired polymer-coated titania. Carbon black is treated with a diazotizing agent containing an ethylenic group, for example, the reaction product of 4-vinylaniline and nitrous acid, to attach ethylenic groups to the carbon black surface, and thereafter may be reacted with a variety of unsaturated monomers in substantially the same way as described for titania.
In the specific processes shown in the Examples of the aforementioned 2002/0185378, the final polymerization steps (the so-called "graft polymerization steps") are conducted in toluene, primarily because this is a solvent known in the polymer industry to have good properties for use in such free radical polymerizations. However, its use as a solvent in processes for preparing polymer-coated electrophoretic pigment particles is markedly inconvenient. For various reasons discussed at length in the aforementioned E Ink and MIT patents and applications, in practice the suspending fluid used in electrophoretic displays is an aliphatic hydrocarbon (alone or in combination with a halocarbon). Thus, since the polymer-coated pigment particles will eventually be dispersed in an aliphatic hydrocarbon, and it is necessary to avoid contaminating this aliphatic hydrocarbon with toluene (since the behavior of electrophoretic media tends in certain cases to be highly sensitive to small changes in the composition of the suspending fluid), after the polymerization in toluene is finished and the polymer-coated pigment separated from the toluene, it is necessary to remove all traces of the toluene before the polymer-coated pigment particles are suspended in the final suspending fluid. In practice, it is necessary to wash the toluene-containing pigment particles from the graft polymerization step one or more times with tetrahydrofuran (THF), centrifuge after washing to separate the pigment from the THF and finally to dry the pigment in an oven to remove the last traces of THF. All these processes have to be carried out separately on the two pigments used in a dual particle electrophoretic medium.
These washing, centrifuging and drying steps are labor intensive and costly. Further expense is incurred by the need to re-disperse the dried pigment in the final suspending fluid. Furthermore, because of the presence of the toluene and THF, the washing, centrifuging and drying steps tend to be hazardous and commercial scale production of the polymer-coated pigment requires the use of explosion-proof ovens, mixers and centrifuges, and explosion-proof electrical control panels, which substantially increases the costs of the production equipment. Also, operator exposure to vapors during processing can be significant despite the use of protective devices or exposure prevention methods. Finally, the drying step may be detrimental to the performance of the pigment in the final electrophoretic medium. It is therefore desirable to find an alternative solvent in which the polymerization reaction can be carried out, and if possible to eliminate the need for drying and re-dispersion of the dried pigment.
Finally, this invention seeks to provide electro-optic displays which are capable of being driven in a simplified manner. Whether a display is reflective or transmissive, and whether or not the electro-optic medium used is bistable, to obtain a high-resolution display, individual pixels of a display must be addressable without interference from adjacent pixels. One way to achieve this objective is to provide an array of non-linear elements, such as transistors or diodes, with at least one non-linear element is associated with each pixel, to produce an "active matrix" display. An addressing or pixel electrode, which addresses one pixel, is connected to an appropriate voltage source through the associated non-linear element. Typically, when the non-linear element is a transistor, the pixel electrode is connected to the drain of the transistor, and this arrangement will be assumed in the following description, although it is essentially arbitrary and the pixel electrode could be connected to the source of the transistor. Conventionally, in high resolution arrays, the pixels are arranged in a two-dimensional array of rows and columns, such that any specific pixel is uniquely defined by the intersection of one specified row and one specified column. The sources of all the transistors in each column are connected to a single column electrode, while the gates of all the transistors in each row are connected to a single row electrode; again the assignment of sources to rows and gates to columns is conventional but essentially arbitrary, and could be reversed if desired. The row electrodes are connected to a row driver, which essentially ensures that at any given moment only one row is selected, i.e., that there is applied to the selected row electrode a voltage such as to ensure that all the transistors in the selected row are conductive, while there is applied to all other rows a voltage such as to ensure that all the transistors in these non-selected rows remain non-conductive. The column electrodes are connected to column drivers, which place upon the various column electrodes voltages selected to drive the pixels in the selected row to their desired optical states. (The aforementioned voltages are relative to a common front electrode which is conventionally provided on the opposed side of the electro-optic medium from the non-linear array and extends across the whole display.) After a pre-selected interval known as the "line address time" the selected row is deselected, the next row is selected, and the voltages on the column drivers are changed to that the next line of the display is written. This process is repeated so that the entire display is written in a row-by-row manner. Thus, in a display with N rows, any given pixel can only be addressed for a fraction 1/N of the time.
Processes for manufacturing active matrix displays are well established. Thin-film transistors, for example, can be fabricated using various deposition and photolithography techniques. A transistor includes a gate electrode, an insulating dielectric layer, a semiconductor layer and source and drain electrodes. Application of a voltage to the gate electrode provides an electric field across the dielectric layer, which dramatically increases the source-to-drain conductivity of the semiconductor layer. This change permits electrical conduction between the source and the drain electrodes. Typically, the gate electrode, the source electrode, and the drain electrode are patterned. In general, the semiconductor layer is also patterned in order to minimize stray conduction (i.e., cross-talk) between neighboring circuit elements.
Liquid crystal displays commonly employ amorphous silicon ("a-Si") thin-film transistors ("TFT's") as switching devices for display pixels. Such TFT's typically have a bottom-gate configuration. Within one pixel, a thin-film capacitor typically holds a charge transferred by the switching TFT. Electrophoretic displays can use similar TFT's with capacitors, although the function of the capacitors differs somewhat from those in liquid crystal displays; see copending application Ser. No. 09/565,413, filed May 5, 2000, and U.S. Patent Publications Nos. 2002/0106847 and 2002/0060321. Thin-film transistors can be fabricated to provide high performance. Fabrication processes, however, can result in significant cost.
In a polymer-dispersed electrophoretic medium of the present invention, the droplets desirably comprise at least about 40 per cent, and preferably about 50 to about 80 per cent, by volume of the electrophoretic medium; see the aforementioned 2002/0131147. It should be stressed that the droplets used in the polymer-dispersed media of the present invention may have any of the combinations of particles and suspending fluids illustrated in FIGS. 1 to 3.
In TFT addressing arrays, pixel electrodes are charged via the TFT's during a line address time. During the line address time, a TFT is switched to a conducting state by changing an applied gate voltage. For example, for an n-type TFT, a gate voltage is switched to a "high" state to switch the TFT into a conducting state.
Undesirably, the pixel electrode typically exhibits a voltage shift when the select line voltage is changed to bring the TFT channel into depletion. The pixel electrode voltage shift occurs because of the capacitance between the pixel electrode and the TFT gate electrode. The voltage shift can be modeled as:ΔVp=GgpΔ/(Cgp+Cp+Cs)
where Cgp is the gate-pixel capacitance, Cp the pixel capacitance, Cs the storage capacitance and Δ is the fraction of the gate voltage shift when the TFT is effectively in depletion. This voltage shift is often referred to as "gate feedthrough".
Gate feedthrough can compensated by shifting the top plane voltage (the voltage applied to the common front electrode) by an amount ΔVp. Complications arise, however, because ΔVp varies from pixel to pixel due to variations of Cgp from pixel to pixel. Thus, voltage biases can persist even when the top plane is shifted to compensate for the average pixel voltage shift. The voltage biases can cause errors in the optical states of pixels, as well as degrade the electro-optic medium.
Variations in Cgp are caused, for example, by misalignment between the two conductive layers used to form the gate and the source-drain levels of the TFT; variations in the gate dielectric thickness; and variations in the line etch, i.e., line width errors.
Some tolerance for mis-registered conductive layers can be obtained by utilizing a gate electrode that completely overlaps the drain electrode. This technique, however, can cause a large gate-pixel capacitance. A large gate-pixel capacitance is undesirable because it can create a need for a large compensation in one of the select line voltage levels. Moreover, existing addressing structures can produce unintended bias voltages, for example, due to pixel-to-pixel variations in gate-pixel capacitance. Such voltages can produce a detrimental effect on certain electro-optic media, particularly when present for extended periods of time.
The foregoing problems render designing a bistable electro-optic display using a electro-optic medium without a voltage threshold a difficult task. Since some pixels on the display may be updated infrequently, if at all, one must ensure that the optical state of the pixel remains unperturbed as much as possible. Practically, this means minimizing the quantity and amplitude of parasitic voltage spikes that are applied to the pixel.
As an example, consider the voltages applied to the source (data) lines of an active matrix display being scanned in the conventional manner described above. In an encapsulated electrophoretic display, these lines are switching between +15V and −15V relative to the common electrode, as frequently as every line address time (the time for which a given row of the active matrix display is selected) of the display. These voltages are capacitively coupled directly to the pixel electrodes of the display, and this coupling may be quite strong in a field-shielded pixel design. Even if these coupled voltage spikes are, over the long term, constrained to be DC balanced, continuous application of these voltage spikes may result in changes in the optical state of the pixels.
It is known that these voltage spikes, and the problems resulting therefrom, can be reduced by providing a pixel storage capacitor coupled to each pixel electrode; see, for example, the aforementioned 2002/0106847. In the prior art, essentially the only practicable way to minimize or eliminate the effects of these voltage spikes is to increase the size of the pixel storage capacitor, which increases the power consumption of the display considerably. In addition, the large size of the storage capacitor limits the maximum achievable resolution, and may result in a decrease in panel yield by increasing the area of metal-metal overlap.
It has now been realized that the problems discussed above can be reduced or eliminated by using, in an active matrix electro-optic display, an electro-optic medium that exhibits a voltage threshold, i.e., a medium which essentially does not switch when subjected to a low but non-zero voltage.

Electrophoretic media and processes for the production thereof


An example of a circuit structure may include a first dielectric layer having first and second surfaces, and a channel extending at least partially between the first and second surfaces and along a length of the first dielectric layer. First and second conductive layers may be disposed on respective portions of the first and second surfaces. A first conductor, having an end, may be disposed on a surface of the first dielectric layer, including at least a first portion extending around at least a portion of the conductor end. The second conductive layer may line the channel extending around a portion of the conductor end. Some examples may include a stripline having a second conductor connected to the first conductor. Some examples may include a cover having a wall positioned on the first dielectric over the second conductor.

Interconnects between transmission lines, and between a transmission line and a circuit structure, such as a lumped element or a substrate component, may produce interference and/or be subject to interference from other circuits. Shielding may reduce interference between communication signals carried on different transmission lines and other circuit structures. A coaxial cable is a transmission line in which an outer conductor that surrounds an inner conductor provides shielding. Such coaxial cables require separate mechanical interconnects that match the cable configuration. Various other forms of transmission lines have been developed that are formed on or in circuit boards. These include microstrip and other strip lines, slot lines, coplanar waveguides, and the like. These transmissions lines, as well as other circuit components are generally not shielded, with the result that evanescent electromagnetic fields may be produced that can interfere with the operation of other circuit components.

Component interconnect with substrate shielding


A computed tomography apparatus configured to assist an operator in easily and correctly making an imaging plan thereby reducing the burden of the operator. The computed tomography apparatus selects at least one of reconstruction methods or changes a parameter by the information the operator inputs or displays its grade information, for example.

The present invention relates to a computed tomography apparatus which takes an image of an object and can reduce the burden of an operator who makes an imaging plan.
An example of a computed tomography apparatus is an X-ray computed-tomography apparatus (hereafter called X-ray CT apparatus). A specific implementation of an X-ray CT apparatus, a multi-slice X-ray CT apparatus has been developed and has found widespread use in recent years. A multi-slice X-ray CT apparatus has a 2-dimensional detector including M channels of N segments detection elements where a plurality of channel detection elements are arranged along the segment direction perpendicular to the channel direction. A multi-slice X-ray CT apparatus collects an image which is characterized by having high resolution and wide range. Examples of multi-slice X-ray CT apparatus include 4 slice type, 8 slice type, and 16 slice type devices . . .
An example of a reconstructing method used with the multi-slice X-ray CT apparatus is a fan-beam reconstruction method which reconstructs the image on the assumption an X-ray beam is parallel to a direction perpendicular to a slice direction although the X-ray beam is, to be exact, a cone-like X-ray beam (cone-beam) which spreads in the slice direction. Another example of a reconstructing method is a cone-beam reconstruction method which reconstructs the image on basis of the angle of the cone-beam. The cone-beam reconstruction method is used when the number of slices to be simultaneously detected equal 8 and the fan-beam reconstruction method is used when the number of slices equal 4.
There are merits and demerits in these reconstruction methods, respectively. For example, the cone-beam reconstruction method makes excellent quality images but requires a longer reconstruction time as compared with the fan-beam reconstruction method because of the need to account for the cone angle. Thus, it is necessary for an operator to understand the special features of each of these reconstruction methods when choosing an appropriate reconstruction method for each patient and for specific images of patients. Setting up the equipment between shots with different methods is very difficult for an operator. Even if the operator is well-skilled in setting up the equipment, this set-up process takes much time and the patient processing efficiency (patient throughput) decreases. Although conventional imaging plan systems configured to assist the operator are known, they do not urge the operator to determine the reconstruction method according to scanning conditions.
In addition, there is another factor which causes a decrease in patient throughput. Another example of a multi-slice X-ray CT apparatus is a multi-slice (e.g., 4 slice or 8 slice) helical X-ray CT apparatus which performs a helical scan. With a multi-slice helical apparatus, the operator can choose the image slice width, thereby creating an imaging plan. The image slice width is defined as the number of imaging slices times the thickness of an imaging slice. The image slice width is also called a scan slice. The thickness of the imaging slice is defined by the thickness of the slice in a rotation center position and desired value is selected (e.g., from 0.5 mm, 1 mm, 2 mm, 3 mm and 4 mm). Thus, the number of imaging slices is the number of detection element segments corresponding to the thickness of the imaging slice (e.g., 0.5 mm).
There are a number of limitations associated with a conventional multi-slice helical X-ray CT apparatus. For example, after the operator sets that the number of imaging slices (e.g., =8) and a helical pitch (e.g., =7), before imaging, the operator may change the number of imaging slices (e.g., from 8 to 4) in response to various demands (quality of image, imaging speed, etc.) changes. It is possible in this case for an object to be imaged with the number of slices=4 and the helical pitch remaining equal to 7 if the operator forgets to change the helical pitch. As a result, an artifact will appear on the reconstructed image. (Note helical pitch is defined as the distance of the movement of the X-ray beam along the rotation axis when it makes a turn around the patient divided by the thickness of the imaging slice.) If the image many such artifacts, it is necessary to re-image the patient and patient throughput decreases.


Methods and apparatus related to the implementation and selection of alterative control information reporting formats are described. A control information reporting format, corresponding to a connection between a wireless terminal and a base station, e.g., for an uplink dedicated control channel, is selected, as a function of at least one of: an application being executed, device capability information, channel condition information, system loading information, and user quality of service information. Different wireless terminals may use different control information reporting formats at the same time. The same wireless terminal may use a different control information reporting format at different times.

In multiple access wireless communications systems, multiple wireless terminals are typically in competition for limited air link resources. A wireless terminal, operating in a state supporting uplink and downlink user data traffic signaling, typically tries to routinely communicate control information to a base station attachment point. In some systems control information may be communicated in the form of control information reports which allow the base station attachment point to obtain information about the wireless terminal status and effectively allocate resources. As the popularity and variety of wireless communication services has increased, the need to support ever larger numbers of concurrent users has grown. In addition, events and/or time of day can drive peak concurrent user demand.
Changes in the number of concurrent users can affect the demand for control information communication resources. However, it should also be appreciated that different wireless terminals can have different needs at different times and that the demand for resources in many cases is not simply a matter of the total number of terminals in the system that have the ability to communicate user data to the base station.
Different wireless terminals using the same base station attachment point often have different reporting needs and priorities. For example, a first wireless terminal operating from a current stationary position, with no or minimal obstructions between itself and the base station attachment point, and needing to communicate small amounts of user data infrequently may have very different control information reporting needs than another, e.g., second, wireless terminal, e.g., a mobile node in a moving automobile, experiencing rapidly changing channel conditions and/or needing to communicate large amounts of data frequently. Using a universal single control information reporting format to report control information to a base station although simple to implement can result in inefficiencies due to tradeoffs made to accommodate the wide variety of different types of anticipated concurrent users with reasonable degree of effectiveness.
In view of the above, it should be appreciated that there is a need for methods and apparatus which provide flexibility with regard to control information reporting, e.g., flexibility in terms of supported report formats. Improved methods and/or apparatus which tend to match a wireless terminal's current needs and/or conditions to a well suited control information report format would tend to increase efficiency and be beneficial, e.g., in terms of increasing traffic throughput capability. The ability to change control information reporting formats, if it could be supported, could also be useful in some cases.

Methods and apparatus related to selecting control channel reporting formats


Soft propylene-based resin compositions, which comprise substantially the following block (I) and block (II):                Block (I): propylene-based polymer having propylene unit chain segments that bond in a mode of head-to-tail bonding, in which the chain segment has an isotactic block-containing stereoblock structure;        Block (II): copolymer containing at least propylene and ethylene, exhibit good flexibility, transparency, and heat resistance.

1. Field of the Invention
The present invention relates to novel, soft propylene-based resin compositions.
2. Discussion of the Background
Soft polyvinyl chloride has heretofore been widely used as a type of soft resin that has flexibility, transparency and heat resistance. However, since polyvinyl chloride produces harmful substances when incinerated, it is desired to develop a novel soft resin which can be substituted for soft polyvinyl chloride. Considering the production costs of resins, an olefin-based soft resin may be one candidate for it.
For example, it is known that ethylene-based resins prepared by copolymerization of ethylene with an α-olefin to have a lower degree of crystallinity have good flexibility and transparency. However, when the content of the comonomer, α-olefin is increased in the ethylene-based resin of this type in order to improve the flexibility and the transparency of the resin, the heat resistance of the resin is often lowered. Accordingly, it is extremely difficult to improve all three properties of flexibility, transparency, and heat resistance of ethylene-based resin.
On the other hand, atactic polypropylene is known as a type of propylene-based soft resin, which is produced by the use of a Ziegler-Natta catalyst or a metallocene catalyst. Of those, the atactic polypropylene that is produced by the use of a Ziegler-Natta catalyst has a broad molecular weight distribution and a broad stereospecificity distribution, and the amount of the sticky component in the polymer is large. Therefore, the polymer is difficult to apply to films and sheets. The other atactic polypropylene that is produced by the use of a metallocene catalyst can be specifically controlled to have a narrowed molecular weight distribution and a narrowed stereospecificity distribution, but its heat resistance is poor since atactic polypropylene is naturally an amorphous polymer. Accordingly, these types of atactic polypropylene also can not satisfy all the requirements of improved flexibility, transparency, and heat resistance, like the above-mentioned ethylene-based copolymer.
On the other hand, stereoblock-structured polypropylene that has isotactic and atactic segments is known. When the isotactic segment is increased in these polymers, then the crystallinity of the polymer is high and therefore the flexibility thereof is poor; and when the isotactic segment in this is reduced, the flexibility and the transparency of the polymer may be high, but the heat resistance thereof is poor and the polymer becomes significantly sticky. Accordingly, the polymer is defective in these points, and it can not satisfy all the requirements of improved flexibility, transparency, and heat resistance. In addition, since the known, stereoblock-structured polypropylene is extremely sticky as so mentioned above, it is generally produced through polymerization in an inert hydrocarbon solvent.
Further, a soft polypropylene-based resin composition that contains atactic polypropylene and an ethylene/propylene copolymer is now under investigation. However, both the atactic polypropylene and the ethylene/propylene copolymer to constitute the resin composition do not exhibit a melting point, or may exhibit a low melting point, and therefore, the resin composition comprising the two can not be very resistant to heat like the above-mentioned atactic polypropylene. To that effect, the resin composition could not satisfy all the requirements of improved flexibility, transparency, and heat resistance.
Thus, there remains for substitutes for soft polyvinyl chloride which do not suffer from the above-mentioned drawbacks,


Described is a method for manufacturing a display including a substrate on which a structure, such as, for instance, a matrix structure in relief, is provided, which structure bounds a number of areas, wherein, with the aid of an inkjet printhead, substantially in each area an amount of liquid is deposited, wherein with the aid of at least one sensor a measurement is performed on the substrate to determine the position of a respective area, and on the basis of the thus determined position the printhead is controlled to deliver an amount of liquid at the correct place. Also described is an apparatus for carrying out the method, a substrate for use in the method and a display obtained with the method.

The substrate known per se comprises a transparent glass plate on which line-shaped, parallel transparent conductors are provided, which have a height of about 100 nm and which are made of Indium Tin Oxide (ITO) or other transparent, conductive material. Next, at right angles to the conductors, line-shaped, parallel, insulating shadowing structures have been applied, having a height of about 1-2 μm.
Thus, between the shadowing structures and the conducting paths, areas are formed having a length and a width of from 5 to some 400 μm. Optionally, on top of the transparent conducting paths and under the shadowing structures, a buffer layer may be provided, having a height of 0.5-5 μm, in which processes have boon provided within the areas mentioned earlier. The recesses extend to the depth of the conductor mentioned earlier, so that pits bounded on five side are formed. To make a polymer OLED display from the substrate, each area is to be filled with a polymer conductor (PDOT) and an organic electroluminescence medium (PPV). In a monochrome display a single type of PPV is deposited in all areas. A color display involves several types of PPV that emit different colors of light (for instance red, green and blue PPV). These types of PPV are to be deposited in different areas.
In the known method and apparatus for filling the areas of a substrate from which a display is being manufactured, use is made of an inkjet printhead which is movable relative to the table on which the substrate is accurately positioned. The table is provided with an electronic ruler, so that the position of the printhead relative to the table is known. In practice, it has been found that under the influence of various disturbing influences, such as, for instance, temperature variations in the substrate, an incorrect alignment of the substrate on the table and mechanical inaccuracies in the transport system of the table and/or the printhead, the liquid to be delivered by the printhead is not deposited in the areas on the substrate with sufficient accuracy (accuracies between 1/10 and 1/1000 of the length or width of the grain are desired). If any one of the areas of the substrate is not properly filled with liquid, such as, or instance, Pdot or red, green or blue PPV, the display will have to be rejected. It is therefore of essential importance that each area of the substrate can be accurately filled with the liquid. Especially when the substrates are greater, there is a substantial chance of defects owing to the disturbing influences mentioned earlier, such as temperature variations in the substrate, an incorrect alignment of the substrate on the table and mechanical inaccuracies in the transport system. To date, it has been attempted to tackle these problems by using a very accurate transport mechanism and very stable tables. However, practice has taught that these measures offer insufficient solace.

Method and apparatus for manufacturing a display, such as, for instance, a polymer OLED display, a display and a substrate for use in the method


Configurations and methods of wireless sound power transmission using a laptop computer may include a transmitter and/or a receiver embedded in the laptop screen. The embedded transmitter may emit SW waves for the generation of pockets of energy that may be utilized by receivers in peripheral devices for charging or powering. Meanwhile, the receiver embedded in the laptop computer may collect SW waves from a separate transmitter for charging or powering the laptop computer.

Laptop or tablet computers are often used in synchronization with several peripheral devices such as computer mice, keyboards, smartphones, headsets, and the like. These peripheral devices may include batteries for allowing wireless operation with the laptop or tablet computer. However, when charge is depleted, the batteries in these peripheral devices may have to be replaced, or said peripheral devices may need to connect to the laptop computer for charging. This may produce tedious continuous connecting/disconnecting of peripheral devices for charging, and may also require the use of all available USB ports in the laptop computer.
What is needed are methods and systems for allowing continuous wireless charging and operation of peripheral devices that may operate in conjunction with a laptop or tablet computer.

This patent is subject to a terminal disclaimer.

Laptop computer as a transmitter for wireless sound charging


The present invention provides a method for improving fuel economy in hybrid vehicles. More precisely, the method of the present invention includes a selectable “learn mode” in which the vehicle can learn a particular driving schedule. After a particular driving schedule is learned, the schedule can be recalled to optimize fuel economy on future trips following the same route. By recalling a learned schedule, the system knows in advance what energy level will be needed and can proactively charge the hybrid vehicle's battery to an appropriate level.

Hybrid vehicles typically include an engine, a battery and an electric motor/generator. The electric motor/generator is generally operated to power a conventional hybrid vehicle until the battery is discharged by a predetermined amount (e.g., 85% discharged). Thereafter, the engine is operated to power the hybrid vehicle and charge the battery. When the battery is sufficiently charged, the engine is stopped and the electric motor/generator is operated to power the hybrid vehicle in a fuel efficient manner.

Method for improving fuel economy in hybrid vehicles


In a method and voice mail system for providing a call answering service between a source telephone and a target telephone, a voice mail system receives an unanswered call directed to the target telephone. If the target telephone is not busy, the voice mail system establishes an outgoing call to the target telephone and conveys to the source telephone a response having embedded media parameters identifying media ports of the voice mail system. In response to an accept call instruction received from the target telephone, the voice mail system terminates the response and bridges all media between the source telephone and the target telephone.

The absence of call screening in network-based voicemail systems constitutes one of the biggest hindrances to the penetration of such systems into US and other markets. Call screening and visual Message Waiting Indicator (MWI via blinking light) are two of the biggest Telephone Answering Machine (TAM) selling features that are generally unavailable through network-based voicemail. Telephone handsets and answering machines at customer premises have traditionally provided these features. A common solution in US markets is to use a Telephone Answering Machine on location (i.e., at home, in the office, etc.), to provide such capabilities. Although network-based voicemail provides many advantages over location-based TAMs, network-based voicemail does not easily provide these two vital capabilities. This causes many subscribers in these markets to prefer home-located TAMs to network-based voicemail, despite other limitations of these TAMs. This technological gap causes network operators to lose potential voicemail air time, and it leaves subscribers with limited functionality.
U.S. Pat. No. 6,310,939 issued Oct. 30, 2001 assigned to Lucent Technologies, Inc. and entitled "Method and apparatus for screening a call as the call is transmitted to voice mail" discloses a screening and monitoring capability for switch based voice messaging systems that allows a called party to hear the caller's voice as the caller leaves a message and to break in to start a normal telephone discussion if the caller or the caller's subject warrants such action. A network service feature is provided that controls the bridging of the connections to the voice mail and the called party's telephone station. The service feature turns the voice mail off and destroys the connection if the monitoring called party speaks.
The approach disclosed in U.S. Pat. No. 6,310,939, incorporated herein by reference, is described only in relation to PSTN networks. However, PSTN network switch-based solutions have the following disadvantages:
Complexity: They require Advanced Intelligent Network Capabilities from the switch. These are not necessary supported by all switches.
Each switch might have its own implementation, so a user might have different user experiences using different switches.
Also in order to provide this service, the telephony switch must use two telephony ports for the whole duration of the call.
U.S. Pat. No. 6,353,660 (Burger et al.) issued Mar. 5, 2002, assigned to SS8 Networks, Inc. and entitled "Voice call processing methods" discloses a call screening method that allows a subscriber to screen calls made to the subscriber from callers using the PSTN while the subscriber may use another communications medium, such as VoIP. An enhanced services platform (ESP) receives a first call from a caller using a particular public telephone number for the particular subscriber. The ESP identifies the particular public telephone number for the particular subscriber. The ESP accesses a database storing a public telephone number and a private packet-based address for subscribers to retrieve a private packet-based address of the particular subscriber on the basis of the particular public telephone number. An introductory message is provided to the caller and prompts the caller to leave a message. The ESP accesses the particular subscriber based on the particular subscriber private packet-based address to establish an audio connection via the communication medium. The subscriber is notified of the first call. If the subscriber answers the call, a communication path is provided between the caller and the subscriber via the communication medium so that the subscriber may hear the caller leave the message but the caller does not hear or know that the particular subscriber is listening. The ESP connects the caller and the subscriber for two-way communication upon the authorization of the subscriber. In another embodiment, both the caller and the subscriber use a packet-based network. The ESP may also record the caller's voice in response to the prompt, and play the recording to the subscriber if the subscriber answers the call.
The system disclosed in U.S. Pat. No. 6,353,660, incorporated herein by reference, operates via PSTN switches. Screening is done not by voice of source subscriber but rather by predetermined criteria such as source ID as accessed from a database that correlates a public (PSTN) telephone number with an IP address. As explained with reference to FIG. 7 of U.S. Pat. No. 6,353,660, the called party may have a designated voice mail system but this serves the sole purpose of recording a message from the calling party only in the event that the called party does not answer an incoming call or rejects it. Thus, the voice mail is provided only for redirecting calls without contacting the called party first (mainly according to the time of the call/business hours). Screening is not performed by the voice mail system but rather by the ESP, which vocalizes a message prompt that is routed to the source. But in order to prompt the target telephone, the ESP must also call the target telephone. Even if a special tone or ringing signal is used that identifies the new call as originating from the ESP, the target subscriber must still answer the call in order to hear the message recorded by the source subscriber. Thus, from the perspective of the called subscriber, until he or she answers the incoming call, there is no way of knowing the identity of the calling party. This means, that the called subscriber will be disturbed to the extent of answering the telephone merely in order to ascertain the identity of the calling party. This is inconvenient even in the event that it transpires that connection to the calling party is required; but if, in fact, no such connection is required the interruption is all the more undesirable.
U.S. Pat. No. 5,625,676 published Apr. 29, 1997 assigned to Active Voice Corporation and entitled "Method and apparatus for monitoring a caller's name while using a telephone" discloses a method and apparatus for an auto attendant system to allow a called party to monitor a screening name left by a caller while the called party is on the telephone with a third party. If the called party wishes, the system can place the third party on hold and connect the caller. Alternatively, the system can redirect the caller to another line or ask the caller to hold. The system is implemented with a second communication channel from the telephone switch system to the called party so that the called party can monitor the screening name left by a caller without first putting the third party on hold or disconnecting from the third party. The system can be configured to automatically monitor each screening name as it is left, without intervention by the called party.
The system disclosed in U.S. Pat. No. 5,625,676, incorporated herein by reference, uses a data network in addition to the regular PSTN and stores voice messages in a server connected to the data network. In one embodiment, all incoming calls are screened and an interactive voice response prompts the calling party to state his or her name. This analog voice information is routed via the regular telephone line to the server where it is converted to data and conveyed to a computer for display thereby. The computer is typically located alongside the called party's POTS telephone extension, so as to allow the called party to see the identity of the calling party and thus decide how to react.
This system also relates to communication initiated in a regular PSTN. The system fails to provide automatic voice screening in an IP LAN where both calling and called parties communicate using VoIP. Moreover, the server operates as a voice mail system and the system is not adapted to extend the utility of a conventional voice mail system for use with VoIP. Also, the called party requires a separate computer to monitor an incoming call and this renders such an approach expensive since each user requires a dedicated computer.
Our co-pending U.S. application Ser. No. 10/739,196 entitled "Method and apparatus for providing a Central Telephony Service for a Calling Party at the Called Party telephone" incorporated herein discloses an improved telephone handset that may be used in a voice mail system in order for the target telephone to achieve two media-related operations:                Bridging the voice stream between a calling party and the voice mail; and        Summation of both bridged streams into one stream which is sent to the target telephone's speaker.
Such an approach is suitable for use with POTS or VoIP telephones or any combination thereof and obviates the need to modify the voice mail system, although it requires a modified telephone handset for use with such a system.
It would therefore be desirable to allow a voice mail system to operate in conjunction with any telephone network, including VoIP networks, so as to provide call screening and answering without the need for a modified telephone handset.

Method and system for providing a call answering service between a source telephone and a target telephone