Abstract: In one embodiment of the present invention, a drive circuit includes: a logic block connected between a source of a first voltage and a source of a second voltage, and a sampler including a plurality of sampling circuits. Each sampling circuit is for sampling, in use, an input data signal and outputting a voltage to a respective output. The drive circuit further includes a voltage booster having plurality of voltage boost circuits, each voltage boost circuit being associated with a respective one of the sampling circuits and, in use, generating a boosted voltage signal and providing the boosted voltage signal to the respective sampling circuit. Each voltage boost circuit is connected between the source of the first voltage and the source of the second voltage. The logic block may be, but is not limited to, a shift register.

Abstract: There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.

Abstract: In one embodiment of the present invention, a drive circuit includes: a logic block connected between a source of a first voltage and a source of a second voltage, and a sampler including a plurality of sampling circuits. Each sampling circuit is for sampling, in use, an input data signal and outputting a voltage to a respective output. The drive circuit further includes a voltage booster having plurality of voltage boost circuits, each voltage boost circuit being associated with a respective one of the sampling circuits and, in use, generating a boosted voltage signal and providing the boosted voltage signal to the respective sampling circuit. Each voltage boost circuit is connected between the source of the first voltage and the source of the second voltage. The logic block may be, but is not limited to, a shift register.

Abstract: There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.

Abstract: A shift register is provided with a shift register section composed of a plurality of stages of flip-flops that operate in synchronization with a clock signal, and level shifters for boosting a start signal lower than a driving voltage and for applying the same to both ends of the shift register section, and the shift register is capable of switching the shift direction in accordance with the switching signal. The foregoing level shifters are current-driving-type level shifters that can operate even in the case where the transistor characteristics are inferior or in the case of fast operations, and that can carry out level shifting even with a start signal having a small amplitude. Furthermore, the foregoing level shifters are provided at both ends of the shift register section, respectively, and one of the same stops operating in accordance with a switching signal, so that consumed power should decrease.

Abstract: There are provided: a first logic operation circuit which performs a logic operation using a high-amplitude logic signal; a transmission system having a load capacitance; and a low-voltage signal generator which is a step-down level shifter transforming an incoming high-amplitude logic signal from the first logic operation circuit to a low-amplitude logic signal having a lower amplitude than the high-amplitude logic signal for output to the transmission system. In the configuration, the first logic operation circuit operates based on a high-amplitude logic signal, and is therefore free from malfunctions and performs operations at high speed. Further, the transmission system introducing a load capacitance transmits a low-amplitude logic signal and therefore restrains increases in electric power consumption and occurrence of unnecessary radiation.

Abstract: An image display device includes two data signal line drive circuits and two scan signal line drive circuits configured differently from each other. Different data signal line drive circuits and scan signal line drive circuit are compatible with different display formats. A display can be produced in the most suitable display format, and power consumption also can be reduced, by switch operating drive circuits according to the kind of input video and environmental conditions. Further, an image can be written over another image by writing video signals to signal lines with a time lag using a plurality of drive circuits; therefore, a superimposed display can be produced without externally processing the video signals. Thus, both a satisfactory image display and low power consumption can be achieved in an image display device.

Abstract: In a shift register provided with flip-flops that operate in synchronism with a clock signal, and a switching means, which is opened and closed in response to an output of the preceding stage of each of the flip-flops, is installed. The clock signal is selectively inputted by the switching means, and the selected clock signal is inverted and used as a shift register output from each of the stages. Moreover, two kinds of clock signals, each of which has a duty ratio of not more than 50% and which have no overlapped portions in their low-level periods, are used so as to prevent the outputs of the shift-register from overlapping each other. Thus, it is possible to provide a shift register which is preferably used for a driving circuit of an image display device, can miniaturize the driving circuit, and can desirably change the pulse width of the output signal, and also to provide an image display device using such a shift register.

Abstract: An image display device includes two data signal line drive circuits and two scan signal line drive circuits configured differently from each other. Different data signal line drive circuits and scan signal line drive circuit are compatible with different display formats. A display can be produced in the most suitable display format, and power consumption also can be reduced, by switch operating drive circuits according to the kind of input video and environmental conditions. Further, an image can be written over another image by writing video signals to signal lines with a time lag using a plurality of drive circuits; therefore, a superimposed display can be produced without externally processing the video signals. Thus, both a satisfactory image display and low power consumption can be achieved in an image display device.

Abstract: A signal line driving circuit includes a shift register having a plurality of shift circuits, each of which shifts a start pulse successively to the next stage, synchronizing with the timing of a clock signal. In this signal line driving circuit, shift pulses are outputted from an AND gate based on output pulses of two adjacent shift circuits. Meanwhile, a width specifying pulse for specifying a pulse width of the shift pulse is inputted via a transistor whose ON/OFF operation is controlled by the shift pulse. A logical operation circuit operates an AND of the shift pulse and the width specifying pulse and outputs the result of operation to a signal line. When the shift pulse is non-active, the transistor becomes OFF, which causes the signal line transmitting the width specifying pulse to be disconnected from the signal line driving circuit, thereby reducing a capacitive load of wiring.

Abstract: A frame rate controller (20) is provided for controlling the frame refresh rate of an active matrix display. The controller (20) comprises a first circuit such as a preloadable synchronous counter (21) which counts vertical synchronization signals VSYNC and supplies an enable signal FE for every Nth frame of data, where N is an integer greater than zero and is selectable. A gating arrangement (26) is controlled by the enable signal FE so that an active matrix display is refreshed for every Nth frame of data, thus allowing a reduction in power consumption of the display.

Abstract: An active matrix devise comprises an array of picture elements. Each picture element has an image element, such as an LCD cell (11) connected to a first storage capacitor 12 and arranged to be connected to a data line 4 by an thin film transistor 10 when activated by a scan signal on a scan line 6. A second storage capacitor 21 can be connected across the first capacitor 12 by means of another thin film transistor 20 when desired so as to increase the storage capacitance at the pixel.

Abstract: A level shifter 13 is provided for each of SR flip flops F1 constituting a shift register 11. The level shifter 13 increases a voltage of a clock signal CK. This arrangement reduces a distance for transmitting a clock signal whose voltage has been increased, as compared with a construction in which a voltage of a clock signal is increased by a single level shifter and the signal is transmitted to each of the flip flops; consequently, a load capacity of the level shifter can be smaller. Furthermore, each of the level shifters is operated during a pulse output of the previous level shifter 13, and the operation is suspended at the end of the pulse output. Thus, the level shifters 13 can operate only when it is necessary to apply a clock signal CK to the corresponding SR flip flop F1. As a result, even when an amplitude of a clock signal is small, it is possible to reduce power consumption of the shift resister under normal operation.

Abstract: A precharge control circuit constituted by (1) a latch circuit mounted in a precharge circuit and (2) a level shifter circuit of a current drive type controlled through an output of the latch circuit is included. The precharge control circuit changes the latch circuit to an active state to cause the level shifter circuit of a current drive type to operate only during a precharge period and also during immediately preceding and succeeding periods, and outside these periods, changes the latch circuit in a non-active state and the level shifter circuit of a current drive type in an operating state to save power consumption in the level shifter circuit. This enables a low-power-consuming precharge circuit, as well as a low-power-consuming image display device with a high quality display capability, to be offered.

Abstract: A level shifting circuit comprises a first low power, low speed level shifter 30 and a second high power, high speed level shifter stage 31. Both the stages 30, 31 have signal inputs connected to a common input IN for receiving signals, at least one of whose levels is to be shifted. The output of the first stage 30 is connected to an enable input EN2 of the second stage 31 and switches the operation of the second stage 31 between an enabled state and a disabled state in which the second stage 31 consumes little or no power. The first stage 30 has an enable input EN1 which may be permanently enabled.

Abstract: An active matrix display comprises an active matrix 1 and a digital data driver 30 formed on a common substrate 100 by a common integration process. The driver 30 comprises a serial to parallel converter 20 having m registers forming at least one set for storing display data for m picture elements, where m is less than the number M of data lines of the matrix 1. The outputs of the registers are connected to m digital/analogue converters 21 whose outputs are connected to m bus lines 50 of an m phase analogue driver 22 in the form of a switching network. The switching network connects in turn groups of m physically adjacent data lines of the matrix 1 to the m bus line, respectively.

Abstract: A switched capacitor digital/analog converter is provided for performing non-linear conversion. An input receives an n bit digital word for conversion. The individual bits of the input word control electronic switches which switch the plates of n capacitors between upper and lower reference voltages. The capacitors have values C0, . . . Cn−1 such that Cx<Cx+1 for each integer x greater than −1 and less than (n−1) and such that Cy+1 is different from 2·Cy for at least one integer y greater than −1 and less than (n−1). The other electrodes of the capacitors are connected together and to the output of the converter.

Abstract: A shift register is provided with a shift register section composed of a plurality of stages of flip-flops that operate in synchronization with a clock signal, and level shifters for boosting a start signal lower than a driving voltage and for applying the same to both ends of the shift register section, and the shift register is capable of switching the shift direction in accordance with the switching signal. The foregoing level shifters are current-driving-type level shifters that can operate even in the case where the transistor characteristics are inferior or in the case of fast operations, and that can carry out level shifting even with a start signal having a small amplitude. Furthermore, the foregoing level shifters are provided at both ends of the shift register section, respectively, and one of the same stops operating in accordance with a switching signal, so that consumed power should decrease.

Abstract: In a shift register provided with flip-flops that operate in synchronism with a clock signal, and a switching means, which is opened and closed in response to an output of the preceding stage of each of the flip-flops, is installed. The clock signal is selectively inputted by the switching means, and the selected clock signal is inverted and used as a shift register output from each of the stages. Moreover, two kinds of clock signals, each of which has a duty ratio of not more than 50% and which have no overlapped portions in their low-level periods, are used so as to prevent the outputs of the shift-register from overlapping each other. Thus, it is possible to provide a shift register which is preferably used for a driving circuit of an image display device, can miniaturize the driving circuit, and can desirably change the pulse width of the output signal, and also to provide an image display device using such a shift register.

Abstract: A shift register is provided with a shift register section composed of a plurality of stages of flip-flops that operate in synchronization with a clock signal, and level shifters for boosting a start signal lower than a driving voltage and for applying the same to both ends of the shift register section, and the shift register is capable of switching the shift direction in accordance with the switching signal. The foregoing level shifters are current-driving-type level shifters that can operate even in the case where the transistor characteristics are inferior or in the case of fast operations, and that can carry out level shifting even with a start signal having a small amplitude. Furthermore, the foregoing level shifters are provided at both ends of the shift register section, respectively, and one of the same stops operating in accordance with a switching signal, so that consumed power should decrease.