Sharp Kabushiki Kaisha Corporation

Other

Hiroshi Take

Makoto Takeda

Hiroshi Hamada

Hisashi Uede

Yasuhiko Inami

Kunihiko Yamamoto

Nobuaki Matsuhashi

Katubumi Koyanagi

Takafumi Kawaguchi

Naofumi Kimura

Kohzo Yano

Kiyoshi Nakazawa

Katsuya Mizukata

Sadatoshi Takechi

Fumiaki Funada

Yutaka Ishii

Tadanori Hishida

Kozo Yano

Shiro Takeda

Junji Kawanishi

Toshifumi Mitsumune

Nobuaki Matsubayashi

The column electrode driving circuit is suitable for driving a display apparatus which has a delta arrangement display unit. The video signals for two rows in the display unit are sampled simultaneously by two sample-hold circuits with sampling timings which differ mutually by one-half of the sampling period. The outputs of the two sample-hold circuits are alternatingly supplied to column electrodes of the display unit.

Column electrode driving circuit for a display apparatus

When a specific signal (such as copy guard signal) is added between horizontal synchronizing signals in a composite synchronizing signal, and the addition period of the specific signal is defined in a specific period on the basis of the vertical synchronizing signal, the composite synchronizing signal is masked to remove the specific signal, thereby obtaining a masked composite synchronizing signal. Afterwards, from the masked composite synchronizing signal, the horizontal synchronizing signal and vertical synchronizing signal are obtained. In the case of composite synchronizing signal containing noise, without masking, the horizontal synchronizing signal and vertical synchronizing signal are directly obtained from the composite synchronizing signal. Therefore, when noise is not present, the horizontal synchronizing signal and vertical synchronizing signal may be obtained without disturbing the video image.

Synchronizing circuit

In a display apparatus such as a liquid crystal display or the like, which adds a switching element for each of the display picture elements arranged in a matrix shape so as to effect the active matrix driving operation, a drive system exits which is capable of varying the number of the scanning lines on the display. The drive system in the simple construction produces a display of a number of input lines, greater in number than the number of scan electrodes on the display apparatus, without producing practical deterioration in the display quality.

Display apparatus with variable scan line selection

A phase looped oscillating circuit includes a signal comparing device which can compare a plurality of different input signals with each other and emit a signal based on this comparison. The signal comparing device emits a control signal to a level converting device, a signal converting device is operatively connected to the level converting device. A signal from the converting device is received by an oscillating device and an oscillating signal is fed back to the signal comparing device via a divider. To compensate for fluctuation of an invertor in the signal converting device, the signal comparing device provides a fixed level signal stabilized at a 50% duty cycle. This stabilization also stabilizes electrical noises that may be present.

Phase locked loop with phase difference signal adjustment circuit

A liquid crystal display device utilizing an insulating substrate, a plurality of transparent electrodes disposed on the insulating substrate in a matrix fashion to form a plurality of pixels, and at least two thin film transistors disposed in the vicinity of each of the transparent electrodes on the insulating substrate, each the thin film transistor having a drain electrode, a source electrode and a gate electrode. The drain electrode is connected to the transparent electrode, a gate electrode line for each line or column of the transparent electrodes is disposed on the insulating substrate in the vicinity thereof and each gate electrode of the thin film transistors connected to each of the transparent electrodes of the line or column are connected in common thereto. The source electrode lines for each column or line of the transparent electrodes are disposed on the insulating substrate in the vicinity thereof and at a right angle to the gate electrode line. The number of the source electrode lines are further equal to the number of the thin film transistors connected to one transparent electrode. Each of the source electrodes of the thin film transistors connected to each of the transparent electrodes of the column or line are thereby connected respectively thereto in a manner capable of connection to an exterior circuit.

Liquid crystal display device

A drive circuit for use in a matrix type liquid crystal display unit having a liquid crytal display panel with switching elements for addressing. The switching elements are provided at picture elements disposed in a matrix type display pattern. The drive circuit includes a row electrode driver coupled not only with terminals of row electrodes provided at one side of the liquid crystal display panel but also to the terminals of the row electrodes provided at opposite sides of the liquid crytal display panel and a changeover terminal for enabling the row electrode driver to drive the terminals of the row electrodes provided at the one side of the liquid crystal display panel or to drive the terminals of the row electrodes provided at the opposite sides of the liquid crystal display panel.

Drive circuit for use in single-sided or opposite-sided type liquid

A liquid crystal display device includes a plurality of scanning electrodes, a plurality of signal electrodes, and a plurality of picture element electrodes connected to intersections of scanning and signal electrodes via a plurality of switching transistors. A plurality of counter electrodes are arranged opposite to the picture element electrodes. The polarity of display signals applied to the signal electrodes is inverted for a period equal to an integer multiple of a pulse width of a scanning pulse applied to the scanning electrodes. Signals of alternating polarity are applied to the counter electrodes in synchronism with the polarity inversion of the display signals. In this way, non-uniform display contrast along the signal electrode direction of the display screen is avoided by eliminating the stray capacitance timing differences according to the position of picture element electrodes along the signal electrode direction of the display screen.

Liquid crystal matrix display device with polarity inversion of signal

A method of driving a matrix-type liquid crystal display panel comprising the step of dividing each scan pulse delivered to a plurality of row electrodes connected to the liquid crystal panel into plural scan periods; supplying video signal data via real-time operation during the initial divided period during alernate scan periods; generating new and proper signal source during the rest of the scan periods; and supplying data from the new signal source so that data can be written into liquid crystal layers. When dividing the width of the scan pulse into n pulses, the frame frequency can be raised n-times, thus making it possible to achieve a satisfactory liquid crystal picture display without the slightest flicker.

Method of driving a liquid crystal matrix display panel

In an active matrix liquid crystal display panel, row electrodes are divided into two portions at the approximate center of the display panel, the left row electrode portion belonging to an odd number row electrode group, and the right row electrode portion to an even number row electrode group. One horizontal scanning is conducted for each pair of left and right row electrodes to write data signals in the display picture elements. The width of a pulse applied to each row electrode corresponds to one horizontal scanning period. There is a phase difference of about 1/2 the horizontal scanning period between the pulses for an odd number row electrode and an even number row electrode, thus minimizing the difference in a write period among the display picture elements in the lateral direction of the display panel.

Drive system for an active matrix liquid crystal display panel having

A color liquid crystal display device which comprises picture element electrodes arranged in a matrix that is made up of the intersecting points of row electrodes and column electrodes, a 1st circuit board with switching elements that are connected to these picture element electrodes, a 2nd circuit board with opposing electrodes, a liquid crystal layer that is inserted in between the said 1st and 2nd circuit boards, a color filter with a specific pattern in between the said 1st and 2nd circuit boards, and a column electrode drive circuit that applies voltage corresponding to color arrangement of the color filter and the density of the display to the said column electrode. The column electrode drive circuit includes a sampling circuit which samples the momentary voltage corresponding to the display picture element out of the display signals that are input.

Drive circuit for color liquid crystal display device

A multiplex-driven liquid crystal X-Y matrix display in which the electrodes are divided into several blocks and a driving voltage is independently applied to each of the blocks. Each driving voltage has a magnitude that is different from the remaining drive voltages. The display panel is free from nonuniform or deteriorated contrast even if it has a large number of scanning electrodes. Besides, for a color display, the color balance is favorably adjusted, realizing a high quality picture image.

Liquid crystal matrix device having separate driving circuits with

A driving circuit for a matrix liquid crystal display device with switching transistors added to respective picture elements is divided into a plurality of blocks each of which selectively drives the switching transistors. The driving circuit is equipped with control means for actuating the blocks one by one in turn while electrically isolating the unactuated blocks from the circuit.

Circuit for driving a matrix display device with a plurality of isolated

A lighting apparatus including a tubular light source and a member having a plurality of reflective surfaces which are angularly set such that light from the light source is reflected in a predetermined direction of a viewing angle by each of the reflective surfaces. A ratio of an apparent width of each of the reflective surfaces to an apparent interval of adjacent ones of the reflective surfaces, when viewed from the predetermined direction of the viewing angle, is so set as to be a function of a distance between the light source and each of the reflective surfaces.

Lighting apparatus

A driver circuit for a matrix-type liquid crystal display panel capable of displaying pictures having the same number of scan lines as a conventional television set without using a frame memory, by applying the mean value of two video signals matching the 1-H advance and 1-H behind odd (even) numbered scan lines, where the video signal in the odd (even) field correctly matches the even (odd) numbered scan lines.

Liquid crystal matrix display panel driver circuit

An active matrix liquid crystal display is provided with one switching transistor connected to each display element. A separate drive circuit is connected to each column of the matrix, each such drive circuit incorporating a buffer circuit which is constructed of an output transistor and three separate switching elements. The buffer circuit transfers a sample of a data input signals to the respective column while requiring reduced power over conventional drivers.

Growing community of inventors

Ikoma, Japan

Hiroshi Take