Abstract:
An apparatus has (1) a liquid crystal display driver having N common drive lines and M segment drive lines; (2) a liquid crystal display having Q common drive leads and R segment drive leads, and (3) P multiplexers. N, M. P, Q and R are each integers greater than zero; Q is greater than N, or R is greater than M, or Q is greater than N and R is greater than M; the multiplexers contain a plurality of switches, wherein the number of switches is equal to (Q minus N) plus (R minus M) and each switch defines a normally-open contact, a normally closed contact and a common contact; the N common drive lines connect directly or through one or more multiplexers with the Q common drive leads, and the M segment drive lines connect directly or through one or more multiplexers with the R segment drive leads. The apparatus may also include a cancel circuit connected to the switches preferably connected to an unused segment drive line to provide a cancel signal.
Abstract:
A liquid-crystal display device (1) comprises a liquid-crystal display panel (2) with a plurality of linear scan electrodes and a plurality of linear signal electrodes, a scan driver (6) for supplying scanning signals to the scan electrodes, a signal driver (7) for supplying data signals to the signal electrodes, and a signal selector (8). The signal selector (8) controls to selectively render the individual scan electrodes active or inactive. The scan driver (6), capable of generating h kinds of scanning signals (h is an integer greater than 1), supplies scanning signals simultaneously to a group of h active scan electrodes during a particular period, and supplies scanning signals simultaneously to another group of h active scan electrodes during another period.
Abstract:
A liquid crystal display including driver circuitry which applies a series of voltage pulses at a frequency of approximately 60 Hz to cumulatively change a reflectance state of a pixel in an array of pixels at a near video updating rate. The display includes a near video rate updating portion, while the remainder of the display has a slower updating frequency or rate. The display is comprised of a bistable cholesteric liquid crystal material sandwiched between an electrode array having a plurality of row and column electrodes. In one operating embodiment, the driver circuitry generates a unipolar row and column waveforms, the row waveforms being applied to the row electrodes and the column waveforms being applied to the column electrodes of the near video rate updating portion. Approximately every 16 milliseconds, a pixel in the near video rate updating portion receives a control voltage pulse corresponding to the difference between the row and column waveforms. Application of six to seven control voltage pulses is sufficient to change the reflectance state of the pixel. In a second operating embodiment, the driver circuitry generates bipolar row and column waveforms. In alternate embodiments, dual column driver circuitry is provided and interlacing schemes are used to increase the number of rows in the near video rate updating portion of the display.
Abstract:
A liquid crystal display in which the voltage difference between scanning signals having at least a resetting period, a selecting period, and a non-selecting period in one frame and data signals is applied across a chiral nematic liquid crytal having at least two stable states. A total of eight voltage levels, i.e., first-group levels (V1, V2, V3 and V4) on the low voltage side and second-group levels (V5, V6, V7 and V8) on the high voltage side, are provided. At every period equal to an integral multiple mH (m is an integer of 2 or larger, and mH NOTEQUAL 1 frame period) of a unit time (1H) corresponding to the selecting period T2 of the scanning signals Yi, the voltage levels of the scanning signals Yi and data signals Xj are alternately changed between the first and second groups. When the data signal (Xj) is at one of the first-group voltage levels, the voltage level during the resetting period (T1) of the scanning signal (Xj) is selected from the second group and, when the data signal (Xj) is at one of the second-group voltage levels, the voltage level during the resetting period (T1) of the scanning signal (Yi) is selected from the first group. When the data signal (Xj) is at one of the first-group voltage levels, the voltage levels during the selecting period (T3) and non-selecting period (T4) of the scanning signal (Yi) are selected from the same first-group and, when the data signal (Xj) is at one of the second-group voltage levels, the voltage levels during the selecting period (T3) and non-selecting period (T4) of the scanning signal (Yi) are selected from the same second-group. As a result, the polarity of the voltage applied across the liquid crystal is inverted at intervals of one mH.
Abstract:
In a method of driving a liquid crystal device, etc., and a display device, particularly those for gradation dispaly, the present invention aims at providing a driving method of a liquid crystal device, etc., and a display device capable of satisfactorily effecting gradation display without causing insufficient contrast, flickers, cross-talk, etc. When effecting multiplex driving of a liquid crystal device, etc., having a liquid crystal layer sandwiched between a substrate having scanning electrodes X1, X2,... and a substrate having signal electrodes X1, Y2,..., the present invention simultaneously selects sequentially a plurality of scanning electrodes, divides the selection period into a plurality of periods, and applies a weighted voltage, which is weighted in accordance with desired display data, in each of the divided selection periods so as to effect gradation display.
Abstract:
A liquid crystal device drive circuit has a positive power supply terminal, a negative power supply terminal, a ground terminal, a control input and an output terminal for connection to a liquid crystal device incorporating a composition having smectic-A properties. The circuit has a first controllable-device for coupling the positive power supply terminal to an output terminal, a second controllable device for coupling the negative power supply terminal to the output termmal and a third controllable device for coupling the ground terminal to the output terminal, the first second and third controllable devices being controllable in accordance with the control input.