Sharp Kabushiki Kaisha Corporation

Sharp Corporation

Yoshiharu Kanatani

Toshihiro Ohba

Hisashi Uede

Etsuo Mizukami

Masahiro Ise

Shigeyuki Harada

Hiroshi Kinoshita

Masashi Kawaguchi

Hirofumi Fukuoka

Chuji Suzuki

Yoshihide Fujioka

Hiroshi Kishishita

Yosihide Fujioka

Toshihiro Yanagi

Hisao Okada

Takeshi Takarada

Shuhei Yasuda

Akio Inohara

Kinichi Isaka

Kuniaki Tanaka

Shigeyuki Uehira

Takeo Fujimoto

Kiyoshi Sawae

Yoshihiko Orii

Tadatsugu Nisitani

Kenzoo Inazaki

Kenzoh Inazaki

Morihisa Sogabe

Yuji Ohno

A method of driving a display apparatus includes the steps of receiving output requests at a interval and outputting an oscillating voltage to a source line connected to display section, the oscillating voltage including a component which oscillates during one output period of time defined by the output requests.

Method of driving a display apparatus

A drive device for driving a matrix-type LCD apparatus comprises a voltage signal supply means for outputting a plurality of voltage signals with different levels. The voltage signals have alternately positive and negative levels with respect to an AC reference voltage applied to a counter-electrode of the LCD apparatus. The AC reference voltage is approximately 180.degree. out-of-phase with the voltage signals. The drive device also comprises a signal electrode drive means which selects one of the voltage signals depending upon an input digital video signal, and which supplies the selected voltage signal to a signal electrode of the LCD apparatus.

Drive device for driving a matrix-type LCD apparatus

A driving circuit for a matrix type liquid crystal display device is disclosed. The driving circuit comprises: a gate driver for, during a writing period, selectively driving a scanning line included in a group of scanning lines which correspond to the field to be scanned, and for, during an erasing period, selectively driving a scanning line included in another group of scanning lines which do not correspond to the field to be scanned; a source driver for, during said writing period of an even field, applying a signal voltage the level of which corresponds to a video signal, to the signal lines, and for, during the erasing period, applying a voltage to the signal lines to set the voltage applied to the picture elements to a level below the threshold level of the picture elements; and another source driver for, during said writing period of an odd field, applying a signal voltage the level of which corresponds to a video signal, to the signal lines, and for, during the erasing period, applying a voltage to the signal lines to set the voltage applied to the picture elements to a level below the threshold level of the picture elements. The writing period and the erasing period shares one horizontal scanning period.

Driving circuit for a matrix type display device

A wiring circuit substrate comprises first circuit element means one one side of the substrate connected to electrode lines of X-Y matrix electrodes, respectively, and second circuit element means in the symmetrical position of the first circuit element means on the other side of the substrate connected to the electrode lines of the X-Y matrix electrodes, respectively, wherein each of leads of the first and the second circuit element means is connected to the output and input lines of the X-Y matrix electrodes via through holes, respectively. The first circuit element comprises integrated transisitors for driving the X-Y matrix electrodes. The second circuit element comprises integrated diodes for protecting an overcurrent in the X-Y matrix electrodes.

Symmetrical circuit arrangement for a X-Y matrix electrode

A driving circuit for a matrix type display device in which a plurality of picture elements are arranged in a matrix is disclosed. The driving circuit comprises a video signal output circuit for supplying video signals through output portions to the display device at each horizontal scan. The video signal output circuit comprises for each of the output portions: a comparison circuit for comparing the level of a video signal to be output, with the level of the output portion which is caused by the video signal output at the previous horizontal scan; and an output level control circuit for, when the level of said video signal to be output is higher than the level of the output portion, raising the level of said output portion to the level substantially identical with the level of the video signal to be output, and, when the level of said video signal to be otuput is lower than the level of the output portion, lowering the level of said output portion to the level substantially identical with the level of the video signal to be output.

A thin film EL display panel is composed of an EL layer placed between scanning electrodes and data side electrodes which are arranged at right angles to the scanning electrodes. A thin film EL display panel drive circuit includes a first and a second switching circuits connected to each of the scanning electrodes to apply voltages of negative and positive polarities, respectively, with respect to the voltage of the data side electrodes; and third and a fourth switching circuits connected to each of the data side electrodes to respectively charge and discharge the EL layer corresponding to the scanning electrode.

Thin film EL display panel drive circuit

A thin-film EL display panel drive circuit capable of varying the drive voltage according to changes in the number of emitting picture elements.

A thin film electroluminescent (EL) display panel drive circuit includes first and second switching circuits for driving scanning electrodes of the panel in two fields, wherein odd numbered scanning electrodes are applied with a negative voltage polarity and even numbered scanning electrodes are provided with a positive voltage polarity in a first field, and the voltage polarities are reversed during the second field. Data signals are applied to data electrodes by a data electrode driver circuit which includes third and fourth switching circuits for providing selected data electrodes with a modulate voltage of a stepwise nature or ground, depending upon whether the selected data electrodes intersect with selected scanning electrodes having a negative or positive voltage polarity respectively. The stepwise modulation voltage is supplied by a control switching circuit which selectively supplies the third switching circuit with voltages of a first level, a second level and a floating level.

Thin film el display panel drive circuit

When driving a thin-film EL display panel having groups of two electrodes on opposing sides of a thin-film EL layer, a voltage is applied so that the polarity of the AC pulse applied to the intersection (picture element) of opposing electrodes is the reverse of the polarity of the AC pulse applied simultaneously or nearly simultaneously to adjacent or nearly adjacent picture elements. This drive method avoids flicker caused by differing luminance intensities resulting from alternating polarity in EL matrix-type displays.

Thin-film EL display panel drive

The preferred embodiment discloses a new thin-film EL display panel drive circuit using EL layers installed between the scan-side electrodes and the data-side electrodes aligned so as to allow them to cross one another, comprising: scan-side electrodes connected to the drain terminal of the N-ch high-voltage resistant driver having a grounded source terminal and also connected to the other drain terminal of the P-ch high-voltage resistant driver having a source terminal connected to the pull-up charge drive circuit and to the write drive circuit via the scan-side common bus line; and data-side electrodes connected to the drain terminal of the N-ch high-voltage resistant driver having a grounded source terminal and also having the anode common terminal connected to the cathode terminal of the diode array connected to the preliminary charge drive circuit via the data-side common bus line. By grounding the source terminal to the scan-side N-ch MOS ICs, some of the floating-output logic-circuit driving power sources and some of the logic signal transmission photo-couplers can be eliminated. This not only saves component elements conventionally needed for the P-N symmetric EL display panel drive circuits, but also securely suppresses noise interference, thus offering an indispensable technique giving an early and overall improvement over those thin-film EL display drive circuits thus far made available.

Thin-film EL display panel drive circuit

A drive circuit for a thin-film electroluminescent (EL) matrix display panel includes an odd side N-ch high voltage MOS driver, and an odd side P-ch high voltage MOS driver connected to odd number scanning electrodes of the thin-film electroluminescent (EL) matrix display panel. Even number scanning electrodes of the thin-film electroluminescent (EL) matrix display panel are connected to an even side N-ch high voltage MOS driver and an even side P-ch high voltage MOS driver. The four MOS drivers are effectively controlled to perform an alternating current driving of the thin-film electroluminescent (EL) matrix display panel.

Drive circuit for a thin-film electroluminescent display panel

A drive circuit for a thin-film electroluminescent (EL) matrix display panel includes an odd side N-ch high voltage MOS driver, and an odd side P-ch high voltage MOS driver connected to odd number scanning electrodes of the thin-film electroluminescent (EL) matrix display panel. Even number scanning electrodes of the thin-film electroluminescent (EL) matrix display panel are connected to an even side N-ch high voltage MOS driver and an even side P-ch high voltage MOS driver. The four MOS drivers are effectively controlled to perform an alternating current driving of the thin-film electroluminescent (EL) matrix display panel. A source level switching circuit is connected to the odd side and even side N-ch high voltage MOS drivers so as to switch the source voltage in synchronization with the field driving of the thin-film electroluminescent (EL) matrix display panel.

Drive system for a thin-film el panel

A drive system for a thin-film EL matrix display panel includes first and second voltage doubler circuits and a DC booster circuit. A 1/4V.sub.M voltage, which has the 1/4 voltage level of the modulation voltage, is applied to the first voltage doubler circuit of which an output voltage is applied to a modulation voltage applying circuit. The 1/4V.sub.M voltage is further applied to the DC booster circuit which develops an output voltage having a voltage level of 1/2V.sub.W. The thus obtained 1/2V.sub.W voltage is applied to the second voltage doubler circuit of which an output voltage is applied to a write voltage applying circuit.

EL panel drive system

Thin-film EL display panel drive circuit with voltage compensation

A method for driving a thin-film electroluminescent (EL) display panel comprises the steps of charging the EL display panel by applying to the EL display panel a voltage of KV.sub.0 where V.sub.0 is a voltage for emitting electroluminescence from the EL display panel and K is more than zero and less than 1, and applying the voltage of V.sub.0 to the EL display panel, whereby the EL display panel is driven with a stepwise driving pulse due to the capacitance feature of the EL display panel. A circuit for enabling the method is also provided.

Growing community of inventors

Nara, Japan

Yoshiharu Kanatani