Abstract: A driving method comprising providing preparatory pulses to each pixel, which establish a predetermined voltage prior to the data pulses. The preparatory pulses may either unload the pixel to a resulting potential of 0 V or load it to a resulting voltage of the same polarity as the charge on the pixel in the subsequent frame time.

Abstract: A display control apparatus for a display device capable of performing updating of a display state for a display element subjected to a change in display includes a display data memory for storing display data, a display controller capable of sequentially reading out the display data stored in the memory and transferring the readout display data to the display device at a predetermined period and capable of performing a partial rewrite operation of the display data stored in the memory, and a rewrite detector for detecting an address for accessing the display data memory to cause the display controller to perform the partial rewrite operation. In addition, a transfer permitting unit reads the address detected by the rewrite detector and permits transfer of only the display data of the read address to the display controller.

Abstract: A light modulating device, such as a ferroelectric liquid crystal display (FLCD) comprises an addressable matrix and modulating elements or pixels and associated circuitry for selectively addressing each element in a series of addressing frames in order to vary the transmission level of each element relative to the transmissions levels of the other elements. Such addressing utilises a temporal dither addressing scheme for addressing at least part of each element within each frame with different combinations of temporal dither signals applied to separately addressable temporal bits within the frame to produce different transmission levels. In order to enable a large number of grey levels to be produced whilst limiting the perceived errors at transitions between different grey levels, the temporal bits are addressed in a first order in a first frame (or in a first spatial location) and in a second order, which is different to the first order, in a second frame (or in a second spatial location).

Abstract: A ferroelectric liquid crystal display comprises data electrodes and strobe electrodes which are connected to data and signal generators. The strobe signal generator supplies strobe signals sequentially to groups of more than one strobe electrode. For instance, the strobe electrodes may be strobed in pairs with the strobe signals being supplied simultaneously to the electrodes of each pair. The data signal generator supplies any of a plurality of different data signals to each of the data electrodes in synchronism with the strobe signals. The data signals are such that all combinations of optical states for the pixels which are connected to the same data electrode and which are strobed simultaneously can be achieved.

Abstract: The invention relates to an improvement in the contrast of an antiferroelectric liquid crystal cell which is constructed with an antiferroelectric liquid crystal sandwiched between a pair of substrates. The antiferroelectric liquid crystal cell has a layer structure such that when a Fourier transform is applied to an output voltage produced as a result of the application of a sinusoidal voltage as a reference frequency to the liquid crystal cell, the transformed output voltage contains frequency components at odd and even multiples of the reference frequency, and the optical path length of the liquid crystal cell lies in the range of 100 nm to 800 nm.

Abstract: A ferroelectric liquid crystal display comprises a layer of ferroelectric liquid crystal material contained between two cell walls, surface treated to align the material in a tilted layer. The walls carry eg row and column electrodes forming an x,y matrix of addressable elements or pixels. Multiplex addressing voltages are provided by driver circuits. An improved addressing is obtained by varying the addressing voltage applied during switching of a pixel to maximize torque applied on liquid crystal molecules. Addressing voltages are from two data waveforms and one strobe waveform; the data waveforms have more than two voltage levels, dc balance, and equivalent rms. values; the strobe waveform has two or more voltage levels (which may include a zero level). The strobe and data waveforms combine to provide a resultant voltage that form an addressing voltage at each pixel.

Abstract: An image display system reproduces a dot clock on the basis of a horizontal sync signal that is generated from a host computer and displays an image on a display unit such as a ferroelectric liquid crystal display. In the host computer, a graphic card is provided with a transmitting unit for transmitting information necessary for display. The display unit comprises a receiver to receive the information necessary for the display and a change unit to change the display contents on the basis of the information received by the receiver. The information necessary for the display includes a sync signal frequency, a dot clock frequency, and an image information display period.

Abstract: A ferroelectric liquid crystal panel including a plurality of scanning electrodes, a plurality of signal electrodes crossing the scanning electrodes, a ferroelectric liquid crystal material having two stable orientation states corresponding to different memory angles and provided at intersections of the plurality of scanning electrodes and the plurality of signal electrodes to form a plurality of pixels is driven. The plurality of pixels each have a first threshold characteristic regarding a voltage for switching a display state of the pixel into a non-display state and a second threshold characteristic regarding a voltage for switching the non-display state of the pixel into the display state.

Abstract: A display control method and apparatus for quantizes input data to binary or multivalued data and delivers the quantized data to a display device such as a matrix panel display. When input data is quantized as by the error-diffusion method and displayed, an area in which there is no change in the display is scanned by multi-interlacing, whereas an area in which there is a change in the display is scanned preferentially and in interlaced fashion. As a result, a flicker-free image having a high picture quality can be displayed at high speed. Further, error produced by the error-diffusion method is reset at a prescribed line and, at the time of the error resetting operation, error-diffusion processing is executed from a line located several lines earlier, thereby preventing the occurrence of sparkling noise and making it possible to display an image of a high picture quality in which the continuity of error-diffusion processing is maintained.

Abstract: A liquid crystal device of the kind in which individually addressable regions are settable to different optical states in response to drive waveforms is described. The waveforms are used to cause the material in different regions to remain set in its existing optical state or to change to another state in dependence upon data to be input to the device, and they are pulse-like in nature and of predetermined amplitude and duration. The operating speed of the device in response to said waveform is improved by causing the profile of the waveforms to depart from the usual squared profile. In one example, the waveforms are caused to have substantially triangular leading and/or trailing edges and the profile causing the material to remain set in its existing optical state differs from that causing the material to change into another optical state.

Abstract: A display controller includes an input device which inputs image data in a first form, and a processor which processes the image data and outputs a control signal which controls a display device. The processor includes a convertor which converts the image data in the first form to image data in a second form. A detector detects a partial area to be rewritten in an image by performing a comparison using the image data in the second form.

Abstract: A ferroelectric liquid crystal display element is structured so that ferroelectric liquid crystal is provided between a plurality of signal line electrodes and a plurality of scanning line electrodes running perpendicular to one another, and includes a signal line electrode driving circuit made up of a gray-scale signal amplifying circuit and a gray-scale signal producing circuit, and a scanning line electrode driving circuit made up of a scanning signal amplifying circuit and a scanning signal producing circuit. The signal line electrode driving circuit applies to the signal line electrodes gray-scale signals including pulses which are phase modulated in accordance with a gray-scale level, and the scanning line electrode driving circuit selectively applies to the scanning line electrodes scanning signals including, in each scanning period, an erasure voltage, a selection voltage, and a non-selection voltage.

Abstract: A driving method for an optical modulation device is applicable to driving of an optical modulation device, e.g. a liquid crystal device having a matrix electrode arrangement comprising a group of scanning electrodes, a group of signal electrodes oppositely spaced from the group of scanning electrodes, and an optical modulation material (e.g. a liquid crystal) showing bistability with respect to an electric filed applied thereto disposed between the groups of scanning electrodes and signal electrodes.

Abstract: A display apparatus which is not adversely affected by a change in the drive waveform or environmental conditions. The display apparatus include a display device, a temperature detection device for detecting the temperature of the display device, and control means that controls the drive conditions for display device. The control means switches a driving waveform based on data from the temperature detection device. The effective value of a selection pulse is preferable changed simultaneously with the waveform switching. The waveform switching may be performed in during a temperature rise rather then during a temperature fall, and may be forbidden for a prescribed period after a waveform switching. The waveform switching may be also be performed between two types of waveforms including or not including a pause period.

Abstract: A display such as a ferroelectric liquid crystal display includes a matrix of pixels, for instance formed at the intersections of data electrodes and strobe electrodes. In order to address an intermediate grey level, each pixel is switched from the normally black mode to the grey level in odd frames and from the normally white mode to the grey level in even frames. Variations in the grey levels, for instance caused by temperature variations, act in opposite directions so that the average grey level over time of the pixel varies relatively little.

Abstract: A display control apparatus includes a storage unit for storing display data at each position corresponding to a display screen of a display device, a setting unit for setting a read start position of the display data from the storage unit, and a data supply unit for reading out display data in a predetermined amount from the storage unit on the basis of the read start position set by the setting unit and supplying the readout display data to the display device. The read start position set by the setting unit is set on the basis of the display data stored in the storage unit. A display control method is also disclosed.

Abstract: A method and apparatus for compensating for temporally varying effects, such as temperature, in a liquid-crystal cell, particularly a wedge-shaped liquid-crystal cell. The temperature of the liquid crystal is measured, either directly with a thermocouple or the like, or by optical means which depend upon the temperature of the liquid crystal. For example, an intensity detector monitors the polarization rotation of a probe beam of light having a substantially different wavelength than that of the beam modulated by the liquid crystal, and a feedback circuit keeps the intensity at a predetermined value corresponding to the optimum path length in the liquid crystal of the modulated beam. The feedback signal from the temperature measurement is used to effectively change the gap filled with liquid crystal. For a wedge-shaped cell, the gap size is changed by moving the cell in the wedge direction.

Abstract: A liquid crystal display apparatus using a ferroelectric liquid crystal with negative dielectric anisotropy in which a blanking pulse having a width that is at least twice of a selecting period and a polarity opposite to a strobe pulse to be applied to a scanning electrode in the selecting period is applied to the scanning electrode before the selecting period during one frame period. Another liquid crystal display apparatus using a ferroelectric liquid crystal with negative dielectric anisotropy in which a strobe pulse is applied to a scanning electrode in a trailing part of the selecting period and a predetermined period that follows the selecting period. A blanking pulse of opposite polarity to the strobe pulse is applied to the scanning electrode before the selecting period in one frame period. A non-selecting period which is at least three times longer than the selecting period is provided between the blanking pulse and the selecting period.

Abstract: A liquid crystal display device of the present invention includes a liquid crystal layer intervened between a first and a second electrode; a circuit for applying a first data signal; a circuit for applying a second data signal; a circuit for holding a selecting signal; and a selecting circuit for applying the first data signal or the second data signal to the first electrode corresponding to the selecting signal held in the holding means. A state of applying the first data signal to a pixel and a state of applying the second data signal to the pixel are determined corresponding to a selecting signal. Since these two states are held by the holding circuit, the selecting signal is not required to be applied when an image displayed does not change, and power consumption is lowered extensively.

Abstract: A driving method for a liquid crystal device includes the steps of providing a first substrate with a unidirectionally aligned data electrode group and a second substrate with a select-electrode group aligned perpendicularly to the data electrode; applying a select pulse to the select electrodes; and providing a pause corresponding to at least one line before a data-pulse sequence is applied to the data-electrode group. The select pulse can be synchronized with the data-pulse sequence by shifting them a half line relative to each other so that the select pulse and the data pulse have opposite polarity in relation to each other. Alternatively, the select pulse is applied while the data pulse sequence is applied to the data electrode group. In the latter case, the time and/or voltage is determined so as to offset the effects of the reversed electric field generated during switching of the liquid crystal.

Abstract: In Deformed Helix Ferro-electric liquid crystal display devices (DHFLCDs) the memory effect in video applications is interrupted by adapting the data voltages of matrix displays based on MIMs or TFTs, dependent on the data in a previous frame, so that the polarization within a cell always switches to a fixed value (zero). In other types of displays (based on diodes) or for less rapid applications, the polarization can also be readily set at this value.

Abstract: An information signal to be fed to an information electrode group is formed of a selection pulse having a pulse width .DELTA.T, a first auxiliary pulse having a polarity opposite to that of the selection pulse and having the same width as that of the selection pulse before the selection pulse, a second auxiliary pulse having a polarity opposite to that of the selection pulse and having the pulse width of one third or less of the pulse width .DELTA.T after the selection pulse, and a third auxiliary pulse having the same polarity as that of the selection pulse and having the pulse width of one third or less of the pulse width .DELTA.T before the first auxiliary pulse. Thus, a driving margin is secured, and a flicker phenomenon is reduced.

Abstract: A passive liquid crystal device (FIG. 1) is driven in a multiplexed manner by a strobe signal (STB) applied in succession to a plurality of row electrodes and data signals (DATa, DATb) applied to a plurality of column electrodes. A resultant signal (RESa, RESb) comprising the combination of the strobe and data signals is applied to the pixels in the device. The liquid crystal device is sensitive to the polarity of the resultant signal. Typically a blanking pulse of a first polarity is applied followed by a resultant signal of the opposite polarity. A first data signal (DATa) is intended to change the state of the relevant pixel (SELECT) while a second data signal (DATa) is intended to leave the pixel in the same state (NON-SELECT). According to the invention the resultant signal (RESa, RESb) comprises at least a portion which is substantially continuously varying. This can be achieved by either or both of the strobe and data signals including such a portion or portions.

Abstract: A display unit receiving a display signal having source image frames encoded at an encoding rate (FR.sub.S). A display screen may be refreshed at a refresh rate which is less than the encoding rate. An actual refresh rate (FR.sub.D) is determined such that FR.sub.S /FR.sub.D =(N+1)/N. To satisfy this equation, the actual refresh rate (FR.sub.D) may be selected to be slightly different from the target refresh rate supported by the display screen. Pixel data elements representing source image frames (received at FR.sub.S) may be written into a frame buffer, and the pixel data elements may be retrieved at a frequency determined by refresh rate FR.sub.D. However, at least a part of every (N+1).sup.st source image frame is not written into the frame buffer to avoid image tearing problems.

Abstract: A ferroelectric liquid crystal display comprises a matrix of pixels addressable by first and second sets of electrode tracks crossing one another at the locations of the pixels. The pixels ale addressed by applying data pulses to the first set of electrode tracks and strobe pulses to the second set of electrode tracks to switch certain pixels selected by the data pulses from a first state to a second state under the effect of the voltage difference between the data pulses and the strobe pulses, and blanking pulses are applied to the second set of electrode tracks to set the pixels to the first state in advance of the application of subsequent strobe pulses to switch selected pixels from the first state to the second state.

Abstract: Subject-matter of this invention is a control method for a ferroelectric liquid crystal matrix panel wherein use is made of selection voltages comprising, at each selection operation, at least two (write) pulses, that is voltages having substantially an identical polarity in finite time intervals, of the same polarity, spaced apart by an interruption wherein voltages of opposite polarity are present, as well specified. The absolute value of the time integral of the voltage during the second pulse (write post-pulse) is in the range of 0.2 Amin to 5 Amin. The control time window associated to the selection voltage includes time intervals wherein voltages of opposite polarity are applied in the interruption, comprehensively extending for at least one and no more than four fifths of the duration of said window, and the absolute value of the integral of the selection voltage in the assembly of said time intervals is in the range between 0.05 Amin and 1 Amin.

Abstract: A liquid crystal device of the type including a pair of substrates having thereon a group of scanning electrodes and a group of data electrodes, and a chiral smectic liquid crystal disposed between the substrates so as to form a pixel at each intersection of the scanning electrodes and the data electrodes, is driven by a driving method causing less crosstalk. The driving method includes the steps of sequentially applying a scanning selection signal to the scanning electrodes, and applying data signals to the data electrodes in synchronism with the scanning selection signal. The scanning selection signal includes a writing pulse having a pulse width .DELTA.T for determining an optical state of the chiral smectic liquid crystal in cooperation with a data signal. Each data signal includes a data pulse for determining an optical state of the chiral smectic liquid crystal in cooperation with the writing pulse.

Abstract: Provided is an electroluminescence apparatus comprising a first unit having a simple matrix electrode structure and an electroluminescence member provided at each intersection between a scanning signal line and an information signal line; and a second unit for sequentially applying a scanning selection signal comprising a first phase and a second phase of mutually different voltage waveforms to the scanning signal line, applying a light emission inducing signal to produce a voltage over a threshold for light emission of the electroluminescence member in synchronism with one of the first phase and the second phase, to the information signal line, and applying a light emission non-inducing signal comprised of a voltage different from that of the light emission inducing signal, in synchronism with the other phase to the information signal line, thereby applying an alternating voltage to the electroluminescence member during a non-selection period of scanning.

Abstract: In the driving of an antiferroelectric liquid crystal panel in which an antiferroelectric liquid crystal is inserted between a pair of substrates having a plurality of scanning electrodes and signal electrodes on the opposing surfaces thereof and there are arranged matrix forming pixels, by providing the period for bringing all the pixels simultaneously to the antiferroelectric state each time the display state of any one of the pixels is changed, the setting to the antiferroelectric state is completely carried out so that the period required for the writing of the pixels can be reduced, even if the length of the selection period for setting to the antiferroelectric state is the same as that of the selection period for setting to the ferroelectric state.

Abstract: An addressable matrix display comprises an addressable matrix of pixels, a first set of electrode tracks on one side of the matrix and a second set of electrode tracks on the other side of the matrix. The sets of electrode tracks cross one another at the locations of the pixels, and the pixels are switchable by the application of respective switching waveforms to the electrode tracks. Furthermore at least one of the electrode tracks has a resistance which varies along the length of the electrode track in order to provide increased temperature uniformity over the display due to power dissipation during switching by the switching waveforms applied to the electrode tracks. More particularly the resistance in an intermediate section of the electrode track is greater than the resistance in two end sections of the electrode track.

Abstract: A liquid crystal apparatus is constituted by a liquid crystal device including a pair of substrates having thereon a group of scanning electrodes and a group of data electrodes intersecting the scanning electrodes so as to form an electrode matrix, and a liquid crystal disposed between the substrates so as to form a pixel at each intersection of the scanning electrodes and the data electrode assuming an ON-state and an OFF-state; scanning signal application means for sequentially applying a scanning signal to the scanning electrodes; data signal-application means for applying data signals including a first data signal and a second data signal selectively to the data electrodes in synchronism with the scanning signal, and control means for periodically switching between a first drive mode of using the first and second data signals for providing the ON- and OFF-states, respectively, of the pixels and a second drive mode of using the first and second data signals for providing the OFF- and ON-states, respectivel

Abstract: An antiferroelectric liquid crystal display apparatus with a high display quality is provided wherein the display screen in the absence of an applied voltage is free from unevenness when power is turned off. An intrinsic antiferroelectric axis direction is set at the midpoint between the average molecular axis direction when the liquid crystal panel is in a rightward-tilted antiferroelectric state and that when it is in a leftward-tilted antiferroelectric state, and the polarization axis of a polarizer is oriented in the same direction as the intrinsic antiferroeelctric axis direction. The rightward-tilted antiferroelectric state refers to a displacement from the average molecular axis direction in the antiferroelectric state, after returning from the rightward-tilted ferroelectric state, while the leftward-tilted antiferroelectric state refers to a displacement from the average molecular axis direction in the antiferroelectric state, after returning from the leftward-tilted ferroelectric state.

Abstract: In a ferroelectric liquid crystal element, in order to excite a reverse electric field within the element in response to a waveform of a non-rewriting voltage, properties of the ferroelectric liquid crystal material, an element structure, driving waveforms, or other factors are adjusted so that molecules of the ferroelectric liquid crystal are allowed to switch between bistable states in response to a waveform of a rewriting voltage, while the ferroelectric liquid crystal exerts an anti-memory phenomenon in response to a waveform of a non-rewriting voltage.

Abstract: A display device comprises a display panel having a ferroelectric liquid crystal, information electrodes and scan electrodes for changing orientations of the ferroelectric liquid crystal in the display panel, and a memory for storing display data. A scan electrode driver supplies a signal to a scan electrode whose ferroelectric liquid crystal is to be reoriented in accordance with the data stored in the memory, and a controller supplies data for designating the scan electrode whose ferroelectric liquid crystal is to be reoriented and data indicating an orientation status to the memory and the scan electrode driver.

Abstract: A display control apparatus includes display device driver means for writing image information into a frame buffer, and display scanning means for sequentially displaying the image data stored in the frame buffer for each line of the display. The display control apparatus further includes partially rewritten line determination means for obtaining from the display device driver means information regarding lines to be written into the frame buffer, and generating in accordance therewith the lines for which the display is to be scanned, and display scan line control means for obtaining from the partially rewritten line determination means lines to be scanned to specify such lines for the display scanning means.

Abstract: In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is used. In the system of the present invention, each pixel has three storage devices to hold RGB analog levels. A latch is used to load these values in parallel. Then an analog 3:1 multiplexer is used to select the proper storage device for the current sequential color. The multiplexer output goes to a comparator, which has a sawtooth waveform input at much faster than the frame rate. The comparator output changes with the sawtooth level, so that PWM control is provided for each pixel. As an alternative, standard analog LCD pixels can be sequentially switched between three color input storage devices.

Abstract: A method realizes gradations on a display employing an antiferroelectric liquid crystal material. The method involves at least two scan periods to drive the display. The waveforms of voltages applied to the display in the two scan periods are symmetrical to each other with respect to 0 V. Each of the scan periods consists of a selected period and an unselected period. The waveform of a voltage applied in the selected period is modulated to control the response time of the antiferroelectric liquid crystal material and adjust the light transmittance thereof in the following unselected period.

Abstract: A matrix-type display apparatus which permits a gradation display of gradation number R (R is an integer of not less than 2) includes m scanning electrodes and scans the m scanning electrodes n times in one frame period. The matrix-type display apparatus performs a time-division gradation display under such condition that a time ratio of display periods of the 1st, the 2nd, . . . , the nth display periods is exactly X:RX: . . . R.sup.n-1 X (X.gtoreq.0). To enable such display, the matrix-type display apparatus is driven based on the below-defined R and n, and X determined based on R and n. R and n satisfy ROT.sub.n (X).noteq.ROT.sub.n ((1+R)X), . . . ROT.sub.n (X).noteq.ROT.sub.n ((1+R+. . .+R.sup.n-2)X, ROT.sub.n ((1+R+. . . +R.sup.n-2)X).noteq.ROT.sub.n ((1+R+. . .+R.sup.n-1)X)=0, wherein ROT.sub.n (a) is a remainder when dividing a (a is 0 or a positive integer) by n is (for example, R=4, n=3). X satisfies (1+R+. . .+R.sup.n-1)X=n(m+b) (b.gtoreq.0) (for example, X=1).

Abstract: In a three-slot addressing scheme for a liquid crystal optical modulator, where the data waveforms comprise a data section, a charge-balancing section and a further section, the form of the further section depends upon the sequence of data waveforms. The further section or pair of adjacent further sections comprises a pair of pulses of opposite polarities which charge-balance each other. The order in which these pulses occur in the pair enhances the effect of the adjacent data section to aid or inhibit switching as appropriate. This facilitates a shorter line address time.

Abstract: In a TFT liquid crystal display device using a DHF liquid crystal, the DHF liquid crystal is alienable to a first alignment state in which liquid crystal molecules are substantially aligned to a first direction, to a second alignment state in which the liquid crystal molecules are substantially aligned to a second direction and to an arbitrary intermediate alignment state between the first and second alignment states, in accordance with a voltage applied between the pixel electrodes and the opposing electrode. One of a pair of polarization plates has an optical axis set in substantially an intermediate direction between the first and second directions. The optical axis of the other polarization plate is set perpendicular to the optical axis of the former polarization plate. A pulse having a voltage whose absolute value corresponds to a display gradation and whose polarity changes frame by frame is applied to the DHF liquid crystal for each pixel in the selection period of that pixel.

Abstract: A driving and switching off circuit is provided for a liquid crystal display device having a memory effect and a plurality of pixels, with each pixel capable of exhibiting two states in accordance with an electric field applied thereto. The circuit comprises a driving circuit for applying a drive signal to the display device to cause all of the pixels to uniformly exhibit one of the two states, a delay circuit for providing an end signal subsequent to the application of the drive signal and a switching circuit, responsive to the delay circuit, for switching off the display device subsequent to causing all the pixels to uniformly exhibit the one state.

Abstract: Antiferroelectric liquid crystal display device provided with a selection period tw, during which a scanning voltage is applied for determining a liquid-crystal display condition or state of a pixel, and further provided with a holding period tk, during which the determined liquid-crystal display state of the pixel is held, and a relaxation period ts, in which the state of the liquid crystal is changed from a ferroelectric state to an antiferroelectric state before the selection period tw and after the holding time tk. Moreover, in the case of this device, at least one horizontal scanning interval, in which the scanning signal voltage is not zero at least during a display signal active period, is provided in the relaxation period ts.

Abstract: A liquid crystal device including a chiral smectic liquid crystal disposed in a bistable alignment state including a first and a second stable state showing an asymmetrical threshold characteristic can be driven for a binary display according to a matrix drive scheme with an improved drive margin. The liquid crystal device is driven so that the liquid crystal is first reset into a less-stable first state regardless of display data and then selectively switched into a more-stable second state depending on given gradation data. The chiral smectic liquid crystal may be disposed in a planar smectic layer structure free from bending.

Abstract: A ferroelectric liquid crystal cell is controlled by applying a strobe pulse and a data pulse to the cell, the magnitude of the data pulse being modulated in order to control the resultant pulse applied to the cell. The resultant pulse includes a pre-pulse on one polarity and a main pulse of the opposite polarity. When applied to a liquid crystal cell of stepped thickness, the application of data pulses of different magnitudes switches regions of different thicknesses of the cell so as to provide grey level capability.

Abstract: A liquid crystal display panel includes a pair of substrates having thereon scanning electrodes and data electrodes so as to form an electrode matrix, and a chiral smectic liquid crystal disposed between the scanning electrodes and data electrodes to form a plurality of smectic layers each including a plurality of liquid crystal molecules. The scanning electrodes and data electrodes are driven to define an effective display region and a frame-like fixed or semi-fixed pattern display region disposed outside the effective display region and extending along at least one side of the display panel. The smectic layers of the chiral smectic liquid crystal are aligned to extend in a direction which is non-parallel with the extension of the frame-like fixed or semi-fixed pattern display region so as to obviate the occurrence of cell thickness irregularity and liquid crystal voids.

Abstract: An active matrix type liquid crystal display device comprises a liquid crystal layer using liquid crystal of a chiral smectic C phase or its sub-phase as a liquid crystal material, pixel electrodes provided on one side of the liquid crystal layer, a common electrode provided on the other side of the liquid crystal layer, switching elements for supplying a predetermined electric potential to the pixel electrodes, and at least two insulation layers, which are provided between the pixel electrode and the liquid crystal layer and between the common electrode and the liquid crystal layer and which include at least alignment films, a sum of values (d/.epsilon.) obtained by dividing a thickness d ?nm! of each insulation layer by a relative dielectric constant .epsilon. thereof at a frequency 1 kHz is set to be between 15 nm and 40 nm.

Abstract: Driver apparatus and methods of driving at least a portion of a cholesteric liquid crystal ("CLC") panel to a state having a given reflectivity. One of the methods includes the steps of: (1) initially driving the portion to a nematic phase, (2) subsequently driving the portion to a cholesteric phase focal-conic state, the cholesteric phase focal-conic state providing a known reference state for subsequent driving of the portion and (3) thereafter driving the portion to the state having the given reflectivity.

Abstract: A liquid crystal apparatus includes (a) a liquid crystal panel including: a pair of substrates having thereon a group of scanning electrodes and a group of data electrodes, respectively, and provided with mutually different alignment characteristics, and a chiral smectic liquid crystal disposed between the substrates so as to form a pixel at each intersection of the scanning electrodes and the data electrodes, and (b) drive means for: sequentially applying a scanning selection signal to the scanning electrodes to select at least one scanning electrode, and applying a data signal having at least three peak values to the data electrodes in synchronism with the scanning selection signal. A DC bias voltage may be applied between the scanning electrodes and the data electrodes, and the polarity of the DC voltage may be switched for each prescribed period. The above system is suitable for obviating or suppressing the "sticking" phenomenon of a chiral smectic liquid crystal.

Abstract: A matrix liquid crystal display using an antiferroelectric liquid crystal prevents the displayed image from tailing off. The liquid crystal display includes a liquid crystal panel, a temperature sensor, a control unit, a scanning electrode driver circuit, and a signal electrode driver circuit. When the temperature of the liquid crystal panel is detected by the temperature sensor, the control unit increases or reduces the de-select period according to the detected temperature. The scanning electrode driver circuit and the signal electrode driver circuit serve to drive scanning electrodes and signal electrodes, respectively included in the liquid crystal panel according to control signals from the control unit and from a level converter. These control signals include a signal indicating the controlled de-select period. Thus, the controlled de-selected period is secured.

Abstract: A display control apparatus is combined to a display apparatus which is constructed by a display element having a memory performance. The display control apparatus comprises a memory unit to store display data to be displayed on the display apparatus, a detection unit to detect the area in which the data has been updated in the memory unit, and a control unit for performing a scan control of the display apparatus in a manner such that the scanning area on the display means corresponding to the area detected by the detection unit is preferentially scanned than the scanning areas on the display apparatus other than the area detected by the detection unit.