Sharp Kabushiki Kaisha Corporation

Sharp Kabushiki Kaishi

Shigeki Tamai

Yoshinori Ogawa

Shigeki Tanaka

Nobuhisa Sakaguchi

Takuya Watanabe

Seijirou Gyouten

Toshio Watanabe

Tomoaki Nakao

A liquid crystal display apparatus drives an active-matrix liquid crystal panel by the use of the line reversal driving method. To do so, a common driver AC-drives one of a pair of electrode in each of all the pixels of the liquid crystal panel. An adding circuit obtains the sum of a plurality of gradation components for deciding the gradations of the pixels in one of the columns in the liquid crystal panel at intervals of the predetermined horizontal period. A voltage setting portion in a source driver corrects a reference voltage difference &#x394;Vref on the basis of the sum at intervals of the horizontal period, divides the corrected reference voltage difference &#x394;Vrefa, decides a plurality of gradation voltages, and selects voltages to be applied to a plurality of data lines in the liquid crystal panel from among the gradation voltages based on the plurality of gradation components. The selected plurality of voltages are applied to the plurality of data lines.

Method of driving liquid crystal panel, and liquid crystal display apparatus

There are provided a liquid-crystal-panel driver IC package which can be mounted compactly on a liquid crystal panel without using any fixing jigs, as well as a liquid crystal panel module which can be downsized by reducing its picture-frame size. First, second glass substrates are laminated together with a specified spacing so as to seal liquid crystals therebetween, and to form a step region A. A plurality of liquid-crystal-panel driver IC TCPs each of which is bent at a bending slit and folded are continuously disposed so as to be arrayed along the step region A. Output leads of the liquid-crystal-panel driver IC TCPs are electrically connected to liquid-crystal driving wiring provided in the step region A of the first, second glass substrates . Then, input-lead side connecting slits of mutually adjoining liquid-crystal-panel driver IC TCPs are superimposed on each other, so that the input leads are electrically connected to each other by soldering or the like at the connecting slits.

Liquid-crystal-panel driver IC package, and liquid crystal panel module

A display drive device of the present invention includes a plurality of cascade connected source driver LSI chips for driving a liquid crystal panel in accordance with an image data signal, and each of the source driver LSI chips includes: a shift register for shifting and transmitting a start pulse signal in synchronization with a clock signal; a sampling memory for sampling the image data signal in accordance with an output of the shift register; and a hold memory for latching a selected image data signal in accordance with a latch signal, wherein a delay circuit for generating the latch signal by delaying the start pulse signal supplied by the shift register in each of the source driver LSI chips is disposed. This arrangement enables the whole device, including a controller, etc., to be produced in a smaller size and at a lower cost.

Display drive device and liquid crystal module incorporating the same

A liquid crystal display apparatus drives an active-matrix liquid crystal panel by the use of the line reversal driving method. To do so, a common driver AC-drives one of a pair of electrode in each of all the pixels of the liquid crystal panel. An adding circuit obtains the sum of a plurality of gradation components for deciding the gradations of the pixels in one of the columns in the liquid crystal panel at intervals of the predetermined horizontal period. A voltage setting portion in a source driver corrects a reference voltage difference Vref on the basis of the sum at intervals of the horizontal period, divides the corrected reference voltage difference Vrefa, decides a plurality of gradation voltages, and selects voltages to be applied to a plurality of data lines in the liquid crystal panel from among the gradation voltages based on the plurality of gradation components. The selected plurality of voltages are applied to the plurality of data lines.

A system construction of semiconductor devices, in which a plurality of semiconductor devices of similar properties are cascaded, each of the semiconductor devices including a clock half-period delaying means which delays a propagation and a reference signal by a half period of the reference signal relative to the input signals before outputting the signals. The propagation signal and the reference signal are cascaded and propagated to the plurality of semiconductors.

System construction of semiconductor devices and liquid crystal display device module using the same

A clock signal CK, picture data signals R&middot;G&middot;B and a source driver starting pulse signal SPI are cascade-connected between first through eighth source drivers in which eight source drivers LSI are cascade-connected. Each of the source drivers LSI is provided with an output control circuit which, up to the output of the start pulse signal SPI to the source driver LSI on the next stage or up to a predetermined time earlier than the output, stops the output of the clock signal to the source driver LSI at the next stage.

Display element driving devices and display module using such a device

The cost of production is reduced by effectively utilizing a substrate and reducing testing time. Adjoining two LCD driver chips mounted on a TCP are arranged with their input lead sides and output lead sides arranged opposite to each other, and the input testing terminals and the output testing terminals are commonized. With this arrangement, the mounting pitch of the LCD driver chips is reduced to effectively utilize a substrate, for the achievement of cost reduction. In this case, the input terminals of the same ordinal numbers are arranged so that they receive an electric power or a signal of an identical electric potential as an input when viewed from both ends of the LCD driver chips. Then, both the LCD drivers are concurrently tested by probing at one time by applying an input signal to an input testing terminal common to both the LCD drivers and concurrently measuring outputs from the respective output testing terminals. Cost reduction is achieved by thus reducing the testing time.

Semiconductor chip, semiconductor device package, probe card and package testing method

The tape carrier package includes a base material, wiring lines formed on the base material, and an insulating top coat formed on the wiring lines to insulate and protect the wiring lines. The wiring lines have a plurality of line exposed portions and line exposed portions exposed from the insulating top coat. By bending the base material along a bending portion formed in the base material, line exposed portions and line exposed portions, which are resultantly opposed to each other, are electrically connected to each other, respectively. A three-dimensional interconnection structure can be realized by bending the base material. As a result, a tape carrier package of multilayer interconnection structure as well as a liquid crystal module using the tape carrier package are provided with low price.

Low-cost tape carrier package and liquid crystal module using the same

An interface circuit which performs level shifting with respect to an inputted digital signal with a small amplitude and outputs a digital signal with a greater amplitude than that of the inputted digital signal is equipped with a filter circuit composed of a low-pass filter and a comparator circuit composed of a plurality of comparators. Digital signals with small amplitudes are supplied to non-inverting input terminals of the comparators, respectively, while a reference voltage signal which is obtained by filtering, through the filter circuit, one predetermined digital signal among the digital signals supplied to the non-inverting input terminals is supplied to every inverting input terminal of the comparators. By so doing, it is possible to provide an interface circuit and a liquid crystal driving circuit which ensure that EMI noise is reduced and various problems which tend to occur in the case where display data input lines increase in number is avoided.

Interface circuit and liquid crystal driving circuit

A tape carrier package is provided with a first region which includes a plurality of input leads for transmitting an input signal between a liquid crystal driver IC chip and a section external to the tape carrier package, and a second region which includes signal transmitting wires for transmitting an input signal among a plurality of the input leads, on one of the surfaces of a tape substrate. Further, in the tape substrate, a folding slit is formed along a boundary between the first region and the second region. The tape substrate is folded into 180 degrees along the folding slit serving as a fold so as to electrically connect a plurality of the input leads and the signal transmitting wires. This arrangement makes it possible to prevent a voltage drop caused by wire resistance.

Tape carrier package with two regions having leds that connect upon folding

A reference voltage having a plurality of voltage levels which increase stepwise over time is supplied to source lines on a display panel through a plurality of analog switches. A value representing a number of gradation display data levels for the source lines during a horizontal scanning period is supplied as one input in to a comparison circuit. A count registered by a counter and representing a gradation clock signal is supplied as a second input. Where the count is less than the value, the analog switches remain conducted. Once the count equals to or exceeds the value, the analog switches are cut off, thus enabling the supplied reference voltage to be applied as a driving voltage to a pair of pixel electrodes. The driving voltage corresponds to the number of gradation display data levels and is held constant at the pixel electrodes for the remaining horizontal scanning period.

Method and apparatus for driving display panel

Input connection terminals of a source driver of an active matrix type liquid crystal display panel, and analog switches are reduced in number. Two of four reference voltages V0, V2, V5 and V7 are combined with each other to output, in total, three combinations (V0, V2), (V2, V5) and (V5, V7) to two reference voltage lines and in each one of three first time periods W1a, W1b and W1c. Analog switches ASW0 and ASW2 for generating voltage are interposed in the respective reference voltage lines. The analog switches are turned on and off under control based on 3-bit display data D0, D1 and D2 for 8-level gradation in second time periods W2 and W3, which are shorter than the first time period W1, within any one of the first time periods W1, whereby a vibrating voltage is supplied to the source lines. Positively utilizing a low pass filter function of the source line due to the capacity and the resistance of the source line, voltages are averaged.

Apparatus for driving display apparatus

Power consumption in a liquid crystal display driver is reduced without degrading display quality of a liquid crystal display. Supply of unnecessary oscillation voltage to the liquid crystal display is stopped by turning off all analog switches AS.sub.0 -AS.sub.7 under the control of a signal TI at the moment when voltage applied to the liquid crystal display reaches a desired DC voltage corresponding to display data D.sub.0 -D.sub.2.

Liquid crystal display driver

In a display apparatus for performing multiple-level gradation display, the number of connection terminals of the drive circuit thereof is reduced so as to reduce the number of analog switches in the drive circuit. First and second reference voltages which rise stepwise with time are supplied to analog switches that are selectively turned on and off in accordance with gradation display data elements. Among potentials included in the changing first and second reference voltages, a potential corresponding to gradation display data is supplied to the pixel electrodes via source lines to perform gradation display in accordance with the gradation display data.

Display panel driving method and display apparatus

A liquid crystal driver IC drives a liquid crystal display apparatus by supplying the potential of one reference power source or the potentials of two reference power sources selected from among a plural number of reference power sources on the basis of the displayed data to the liquid crystal display apparatus by time sharing. The supply line of the reference power source for an intermediate value among the plurality of reference power sources is divided into at least two supply lines and the fixed directions of current flowing through the respective divided lines are maintained. The voltage-drop and voltage build-up of the reference power sources resulting from the electric charge flowing into and out of the reference power sources are limited to one of each of the two supply lines. The resulting voltage fluctuations of the reference power source are low, making it possible to supply the liquid crystal display apparatus with stable voltage required for the improvement of display definition.

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Nara, Japan

Shigeki Tamai