Patents by Inventor Toshihiro Ohba
Toshihiro Ohba has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 4935671Abstract: 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.Type: GrantFiled: August 8, 1988Date of Patent: June 19, 1990Assignee: Sharp Kabushiki KaishaInventors: Shigeyuki Harada, Kinichi Isaka, Toshihiro Ohba, Masashi Kawaguchi, Hiroshi Kishishita, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4914353Abstract: 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.Type: GrantFiled: July 8, 1988Date of Patent: April 3, 1990Assignee: Sharp Kabushiki KaishaInventors: Shigeyuki Harada, Toshihiro Ohba, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4893060Abstract: 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.Type: GrantFiled: April 25, 1988Date of Patent: January 9, 1990Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4888523Abstract: The present invention relates to a driving circuit of a thin film electroluminescent (EL) display, wherein a high withstand-voltage driver IC composed of a bi-directional switching element having push/pull function is connected with one or both of the scanning electrodes and the data electrodes of EL display, the bi-directional switching circuit for applying the writing voltage or the modulation voltage is applied with the pull up common line of each of the drivers IC and the pull down common line, a switch for extremely recovering, after the thin film EL element has emitted its light, the electric charge accumulated on the thin film EL display element, and a capacitor for accumulating the drawn out electric charge are disposed in the bi-directional switching circuit, and the modulation accumulation electric charge accumulated on the film EL display element after the light emission is accumulated on the capacitor, so that the modulation consumption power occupying the majority of the driving power without theType: GrantFiled: April 3, 1989Date of Patent: December 19, 1989Assignee: Sharp Kabushiki KaishaInventors: Kazuo Shoji, Yosihide Fujioka, Shigeyuki Harada, Toshihiro Ohba
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Patent number: 4866348Abstract: 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.Type: GrantFiled: April 28, 1987Date of Patent: September 12, 1989Assignee: Sharp Kabushiki KaishaInventors: Shigeyuki Harada, Toshihiro Ohba, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4864182Abstract: A thin film EL display device wherein an EL layer is interposed between scanning side electrodes and data side electrodes which are arranged to cross one another. A data side driver IC, including switching elements for charging and discharging, is connected to the data side electrodes, and switching circuits for applying modulation voltage are connected to a pull-up common line of the data side driver IC. The switching circuits are provided with switches for removing the charge stored in the thin film EL device after the thin film EL device has emitted light and a capacitor for storing the removed charge, whereby the charge stored in the capacitor can be reused in the next light emission for the purpose of reducing power consumption.Type: GrantFiled: January 6, 1988Date of Patent: September 5, 1989Assignee: Sharp Kabushiki KaishaInventors: Yoshihide Fujioka, Kazuo Shoji, Shigeyuki Harada, Toshihiro Ohba
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Patent number: 4823121Abstract: An EL (electroluminescent) panel driving system includes a display control circuit for producing, line by line, an image data. The image data of each line is defined by a combination of a HIGH level signal representing a spot illumination of the EL panel and a LOW level signal representing a non-illumination of a spot on the EL panel. The system further includes a pre-charge circuit and a pull-up charge circuit for providing a first range voltage to the EL panel at the beginning of each line scan operation to make the EL panel ready to illuminate, and a write-in circuit and a source level switching circuit for providing a second range voltage to the EL panel to permit the spot illumination of the EL panel in accordance with the HIGH level signals contained in the image data. These four circuits are turned on by four signals.Type: GrantFiled: October 15, 1986Date of Patent: April 18, 1989Assignee: Sharp Kabushiki KaishaInventors: Atsushi Sakamoto, Shigeyuki Harada, Toshihiro Ohba
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Patent number: 4801920Abstract: 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.Type: GrantFiled: September 16, 1983Date of Patent: January 31, 1989Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Hiroshi Kinoshita, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4686426Abstract: A thin-film EL display panel drive circuit capable of varying the drive voltage according to changes in the number of emitting picture elements.Type: GrantFiled: September 26, 1985Date of Patent: August 11, 1987Assignee: Sharp Kabushiki KaishaInventors: Yoshihide Fujioka, Shigeyuki Harada, Toshihiro Ohba, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4594589Abstract: 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.Type: GrantFiled: August 27, 1982Date of Patent: June 10, 1986Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Hiroshi Kinoshita, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4485379Abstract: An EL panel including an array of scan electrodes, an array of data electrodes crossing the scan electrodes and a plurality of pixels each lying sandwiched between a respective one of the scan electrodes and a respective one of data electrodes is driven by a circuit for applying sequentially a write pulse voltage to the scan electrodes in a line scanning fashion and a circuit for applying a refresh pulse voltage of a polarity opposite to that of the write pulse voltage throughout the panel upon completion of field scanning. The system further includes a circuit for applying throughout the display panel upon completion of field scanning a write compensation pulse of the same polarity as that of the refresh pulse voltage and an amplitude insufficient to cause electroluminescence, and a refresh compensation pulse of a polarity opposite to that of the refresh pulse and an amplitude not enough to cause electroluminescence.Type: GrantFiled: February 10, 1982Date of Patent: November 27, 1984Assignee: Sharp Kabushiki KaishaInventors: Hiroshi Kinoshita, Toshihiro Ohba, Masashi Kawaguchi, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4479120Abstract: A display device includes an EL panel including an array of scan electrodes, an array of data electrodes crossing the scan electrodes and a plurality of pixels each lying sandwiched between a respective one of the scan electrodes and a respective one of data electrodes, a circuit for applying sequentially a write pulse voltage V.sub.W to the scan electrodes in a line scanning fashion and a circuit for applying a refresh pulse voltage V.sub.R of a polarity opposite that of the write pulse voltage V.sub.W throughout the panel upon completion of field scanning. A circuit is further provided for applying throughout the display panel upon completion of field scanning a pulse voltage having the same polarity as that of the refresh pulse V.sub.R and an amplitude insufficient to cause electroluminescence. Alternatively, a pulse voltage having a polarity opposite that of the refresh pulse V.sub.R and an amplitude insufficient to cause electroluminescence may be applied after the application of the refresh pulse V.sub.Type: GrantFiled: October 13, 1981Date of Patent: October 23, 1984Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Masashi Kawaguchi, Hiroshi Kinoshita, Yoshiharu Kanatani, Hisashi Uede
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Patent number: 4468659Abstract: An electroluminescent (EL) display panel circuit comprises an EL display panel having four sides, a driver circuit for driving the EL display panel, the driver circuit comprising shift register circuits for selectively sending data in bi-directions, terminals of the EL display panel connected to the driver circuit, the terminals being led out from at least two sides of the EL display panel, and flexible substrates for supporting the driver circuit in such a manner that one of the flexible substrates corresponding to one of at least two of the terminals is symmetrical to the other of the flexible substrates corresponding to the opposing other of the at least two of the terminals.Type: GrantFiled: August 19, 1981Date of Patent: August 28, 1984Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Yoshiharu Kanatani, Hiroshi Kinoshita, Morihisa Sogabe, Yoshihide Fujioka
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Patent number: 4338598Abstract: A thin-film EL display panel has a plurality of scanning side electrodes and a plurality of data side electrodes. The thin-film EL display panel is excited to emit light through a pre-charge mode, a discharge modulation mode and a write mode. A voltage lower than a modulation voltage is supplied from the data side electrodes to the thin-film EL display panel as a first pre-charge voltage. Thereafter, a difference voltage between the first pre-charge voltage and the modulation voltage is supplied from the scanning side electrodes to the panel as a second pre-charge voltage, thus reducing power consumption to a minimum during the pre-charge mode.Type: GrantFiled: January 7, 1980Date of Patent: July 6, 1982Assignee: Sharp Kabushiki KaishaInventors: Toshihiro Ohba, Shuhei Yasuda, Yoshiharu Kanatani
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Patent number: 4207617Abstract: An EL display panel comprising an electroluminescent element made of, for example, a ZnS:Mn layer sandwiched between a pair of dielectric layers exhibits hysteresis properties within light intensity versus applied voltage characteristics. A front electrode is formed on one of the dielectric layers, and a rear electrode is formed on the other dielectric layer in order to apply a sustaining voltage signal across the electroluminescent element for maintaining the memoried display information. An electron beam is applied to a desired position on the EL display panel through the rear electrode at a time when the sustaining voltage signal bears the zero level in order to erase the memoried information. The memoried display information is electrically read out by detecting a polarization relaxation current which flows through a memoried display position when an electron beam is applied thereto.Type: GrantFiled: June 28, 1978Date of Patent: June 10, 1980Assignee: Sharp Kabushiki KaishaInventors: Shuhei Yasuda, Toshihiro Ohba, Chugi Suzuki, Masayoshi Koba, Jun Kudo
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Patent number: 4206460Abstract: An EL display panel comprises an electroluminescent element made of, for example, a ZnS:Mn layer sandwiched between a pair of dielectric layers. A front electrode is formed on one of the dielectric layers, and a rear electrode is formed on the other dielectric layer in order to apply a voltage signal across the electroluminescent element. An electron beam is applied to the electroluminescent element through the rear electrode to provide the electroluminescence at the position to which the electron beam is applied. A desired pattern is displayed on the EL display panel by properly controlling the application of the electron beam.Type: GrantFiled: March 8, 1978Date of Patent: June 3, 1980Assignee: Sharp Kabushiki KaishaInventors: Shuhei Yasuda, Toshihiro Ohba, Chuji Suzuki
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Patent number: 4160923Abstract: In a touch sensitive electronic switching circuit including a C-MOS inverter, for use in electronic wristwatches, a resistor of 1-10 M.OMEGA. is connected to the source electrode of the P-channel MOS type field effect transistor included within the C-MOS inverter, whereby the threshold voltage level of the C-MOS inverter is shifted to a low level to enhance the reliability of the touch sensitive electronic switching circuit. In another embodiment, the resistor of 1-10 M.OMEGA. is connected to the source electrode of the N-channel MOS type field effect transistor included within the C-MOS inverter, whereby the threshold voltage level of the C-MOS inverter is shifted to a high level to enhance the reliability of the touch sensitive electronic switching circuit.Type: GrantFiled: December 22, 1977Date of Patent: July 10, 1979Assignee: Sharp Kabushiki KaishaInventors: Hidetoshi Maeda, Toshihiro Ohba
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Patent number: 4099074Abstract: In a touch sensitive electronic switching circuit including a C-MOS inverter, for use in an electronic wristwatch, a resistor of about 5 M.OMEGA. is connected between the gate electrode of the C-MOS inverter and an input terminal associated with a touch sensitive electrode formed on a preferred position of the casing of the electronic wristwatch. The resistor of about 5 M.OMEGA. functions to prevent the C-MOS inverter from being damaged by an erroneous application of a high voltage to the touch sensitive electrode.Type: GrantFiled: March 5, 1976Date of Patent: July 4, 1978Assignee: Sharp Kabushiki KaishaInventors: Hidetoshi Maeda, Toshihiro Ohba