Patents by Inventor Kazuo Ookado
Kazuo Ookado 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: 9336733Abstract: A liquid crystal display system including: a liquid crystal display panel for displaying image data; a semiconductor device including a display driving circuit configured to drive the liquid crystal display panel, said display driving circuit having a function of generating gray scale voltages based on a gamma characteristic curve, said display driving circuit including: an interface circuit coupled to plurality of external terminals for inputting a first, second and third value which define the gamma characteristic curve; a first register configured to store the first value that adjusts an amplitude of the gamma characteristic curve; a second register configured to store the second value that adjusts a gradient of the gamma characteristic curve; a third register configured to store the third value making a micro adjustment of the gamma characteristic curve; and a generation circuit configured to generate the gray scale voltages based on the gamma characteristic curve.Type: GrantFiled: January 21, 2014Date of Patent: May 10, 2016Assignee: Renesas Electronics CorporationInventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
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Publication number: 20140132494Abstract: A liquid crystal display system including: a liquid crystal display panel for displaying image data; a semiconductor device including a display driving circuit configured to drive the liquid crystal display panel, said display driving circuit having a function of generating gray scale voltages based on a gamma characteristic curve, said display driving circuit including: an interface circuit coupled to plurality of external terminals for inputting a first, second and third value which define the gamma characteristic curve; a first register configured to store the first value that adjusts an amplitude of the gamma characteristic curve; a second register configured to store the second value that adjusts a gradient of the gamma characteristic curve; a third register configured to store the third value making a micro adjustment of the gamma characteristic curve; and a generation circuit configured to generate the gray scale voltages based on the gamma characteristic curve.Type: ApplicationFiled: January 21, 2014Publication date: May 15, 2014Applicant: Renesas Electronics CorporationInventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Hiroki AIZAWA
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Patent number: 8633881Abstract: Display driving arrangements including: generation circuit dividing a reference voltage by variable resistors for plural levels of voltages; a decoder circuit decoding gray scale voltage corresponding to the display data among the levels of voltages; and a register setting variable resisters resistance values to adjust amplitude and gradient of the gamma characteristic curve of the gray scale voltages with respect to the gray scale number, the generation circuit having a group of resistive voltage dividing circuits dividing the reference voltage, a variable resister amplitude adjusting the gamma characteristic curve in accordance with register setting values connected with a side of the reference voltage in series, being closer to the side of the reference voltage than the group of resistive voltage dividing circuits, a variable resister to adjust the gradient of the gamma characteristic curve per the register setting values connected within the group of resistive voltage dividing circuits in series.Type: GrantFiled: February 14, 2012Date of Patent: January 21, 2014Assignee: Renesas Electronics CorporationInventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
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Publication number: 20120139972Abstract: Display driving arrangements including: generation circuit dividing a reference voltage by variable resistors for plural levels of voltages; a decoder circuit decoding gray scale voltage corresponding to the display data among the levels of voltages; and a register setting variable resisters resistance values to adjust amplitude and gradient of the gamma characteristic curve of the gray scale voltages with respect to the gray scale number, the generation circuit having a group of resistive voltage dividing circuits dividing the reference voltage, a variable resister amplitude adjusting the gamma characteristic curve in accordance with register setting values connected with a side of the reference voltage in series, being closer to the side of the reference voltage than the group of resistive voltage dividing circuits, a variable resister to adjust the gradient of the gamma characteristic curve per the register setting values connected within the group of resistive voltage dividing circuits in series.Type: ApplicationFiled: February 14, 2012Publication date: June 7, 2012Inventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Hiroki AIZAWA
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Patent number: 8120561Abstract: A display driving circuit to supply a gray scale voltage corresponding to display data to a display panel, the display driving circuit including: a generation circuit to divide a reference voltage to generate a plurality of levels of the gray scale voltages; an interface circuit; a selection circuit to select the gray scale voltage corresponding to the display data from the plurality of levels of voltages; a first register to store a setting value that adjusts the amplitude of a gamma characteristic curve from outside via the interface circuit; and a second register to store a setting value that adjusts the gradient of the gamma characteristic curve from outside via the interface circuit; and a third register to store a setting value for micro adjusting the gamma characteristic curve from outside via the interface circuit; wherein the first, second and third registers are assigned different addresses.Type: GrantFiled: March 26, 2009Date of Patent: February 21, 2012Assignee: Renesas Electronics CorporationInventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
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Patent number: 8094104Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.Type: GrantFiled: August 3, 2007Date of Patent: January 10, 2012Assignees: Hitachi ULSI Systems Co., Ltd., Renesas Electronics CorporationInventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
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Publication number: 20110148953Abstract: A display driver having a first mode where a number of colors to be displayed is smaller than a predetermined number and a second mode where a number of colors to be displayed is equal to or larger than the predetermined number. A generation circuit generates gray scale voltages having a plurality of levels for positive polarity and negative polarity. In the first mode, the generation circuit decreases a current flowing into an internal circuit which generates a gray scale voltage of an intermediate level other than two gray scale voltages of a lowest and a highest level, in comparison to a current flowing in the second mode. In the first mode, the selection circuit selects a gray scale voltage in accordance with the display data, from the two gray scale voltages of the lowest and the highest level gray scale voltage which are generated from the generation circuit.Type: ApplicationFiled: March 1, 2011Publication date: June 23, 2011Inventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Atsuhiro HIGA
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Patent number: 7898555Abstract: A generation circuit generates gray scale voltages having a plurality of levels for positive polarity and gray scale voltages having a plurality of levels for negative polarity; wherein said generation circuit, in the mode in which the number of colors to be displayed on a display panel is small, decreases a current flowing into an internal circuit which generates a gray scale voltage of an intermediate level other than two gray scale voltages of a gray scale voltage of the most lowest level and a gray scale voltage of the most highest level among the gray scale voltages of said plurality of levels, in comparison to a current flowing in the other mode; and wherein said selection circuit, in the mode in which the number of colors to be displayed on said display panel is small, selects said gray scale voltage according to said display data, from the two gray scale voltages of said most lowest level gray scale voltage and said most highest level gray scale voltage which are generated from said generation circuitType: GrantFiled: July 11, 2007Date of Patent: March 1, 2011Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
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Patent number: 7750882Abstract: A display apparatus for displaying display data, including: a first driver applying a gray scale voltage to first lines in response to display data; and a second driver applying a selection voltage to second lines in a case of selecting a line of a pixel and a non-selecting voltage to the second lines in a case of not selecting a line of a pixel, wherein the second driver in turn applies the selection voltage to each line of the second lines, wherein said second driver applies the selection voltage once per line to the second lines in one frame period, wherein the second driver applies the selection voltage to one line of the second lines in a first period of one horizontal scanning period and applies the non-selecting voltage to the same one line of the second lines in a second period of the same one horizontal scanning period.Type: GrantFiled: January 26, 2006Date of Patent: July 6, 2010Assignee: Hitachi, Ltd.Inventors: Akihito Akai, Yasuyuki Kudo, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
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Publication number: 20090184985Abstract: A display driving circuit to supply a gray scale voltage corresponding to display data to a display panel, the display driving circuit including: a generation circuit to divide a reference voltage to generate a plurality of levels of the gray scale voltages; an interface circuit; a selection circuit to select the gray scale voltage corresponding to the display data from the plurality of levels of voltages; a first register to store a setting value that adjusts the amplitude of a gamma characteristic curve from outside via the interface circuit; and a second register to store a setting value that adjusts the gradient of the gamma characteristic curve from outside via the interface circuit; and a third register to store a setting value for micro adjusting the gamma characteristic curve from outside via the interface circuit; wherein the first, second and third registers are assigned different addresses.Type: ApplicationFiled: March 26, 2009Publication date: July 23, 2009Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
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Patent number: 7511693Abstract: A display driver adjustable for a gamma specification of a liquid display panel, including: a system interface receiving display data from an external; a memory storing the display data; a grayscale voltage generator generating a plurality of grayscale voltages; a gamma adjusting circuit adjusting the gamma specification; and an output circuit outputting the grayscale voltage in response to the display data from the memory to the liquid display panel, wherein the gamma adjusting circuit includes: a gradient adjustment register controlling variable resistors of a ladder resistor; an amplitude/reference adjustment register; and a micro adjustment register, wherein the gradient adjustment register, the amplitude/reference adjustment register and micro adjustment register, are independently set in accordance with red, green and blue, respectively.Type: GrantFiled: October 13, 2005Date of Patent: March 31, 2009Assignee: Renesas Technology Corp.Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
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Patent number: 7480164Abstract: There is to be provided a liquid crystal drive controller with a built-in power supply circuit wherein latch-up is made difficult to arise even if one amplitude level of the segment line drive voltage is set to the ground potential and the levels of other liquid crystal drive voltages are determined accordingly. A semiconductor integrated circuit with a built-in power supply circuit, wherein a negative voltage generated in a power supply circuit is applied to a substrate or a well region as a bias voltage, is provided with a switch for temporarily applying the ground potential to the substrate or well region to be biased with the negative voltage at the time of starting up the power supply circuit.Type: GrantFiled: October 15, 2007Date of Patent: January 20, 2009Assignee: Renesas Technology Corp.Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Patent number: 7450099Abstract: A display drive circuit for outputting a gray scale voltage according to display data includes a generation circuit generating gray scale voltages of a plurality of levels, and a selection circuit which selects a gray scale voltage according to the display data. When the number of colors to be displayed is small, the generation circuit decreases a current flowing into an internal circuit which generates a gray scale voltage of an intermediate level other than two gray scale voltages of a gray scale voltage of the most lowest level and a gray scale voltage of the most highest level among the gray scale voltages of the plurality of levels, and the selection circuit selects the gray scale voltage according to the display data from the most lowest level gray scale voltage and the most highest level gray scale voltage which are generated.Type: GrantFiled: August 16, 2004Date of Patent: November 11, 2008Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
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Patent number: 7405732Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.Type: GrantFiled: October 25, 2001Date of Patent: July 29, 2008Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
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Publication number: 20080049480Abstract: There is to be provided a liquid crystal drive controller with a built-in power supply circuit wherein latch-up is made difficult to arise even if one amplitude level of the segment line drive voltage is set to the ground potential and the levels of other liquid crystal drive voltages are determined accordingly. A semiconductor integrated circuit with a built-in power supply circuit, wherein a negative voltage generated in a power supply circuit is applied to a substrate or a well region as a bias voltage, is provided with a switch for temporarily applying the ground potential to the substrate or well region to be biased with the negative voltage at the time of starting up the power supply circuit.Type: ApplicationFiled: October 15, 2007Publication date: February 28, 2008Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Patent number: 7317627Abstract: There is to be provided a liquid crystal drive controller with a built-in power supply circuit wherein latch-up is made difficult to arise even if one amplitude level of the segment line drive voltage is set to the ground potential and the levels of other liquid crystal drive voltages are determined accordingly. A semiconductor integrated circuit with a built-in power supply circuit, wherein a negative voltage generated in a power supply circuit is applied to a substrate or a well region as a bias voltage, is provided with a switch for temporarily applying the ground potential to the substrate or well region to be biased with the negative voltage at the time of starting up the power supply circuit.Type: GrantFiled: May 8, 2007Date of Patent: January 8, 2008Assignee: Renesas Technology Corp.Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Publication number: 20070279358Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.Type: ApplicationFiled: August 3, 2007Publication date: December 6, 2007Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
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Publication number: 20070279357Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.Type: ApplicationFiled: August 3, 2007Publication date: December 6, 2007Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
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Publication number: 20070279404Abstract: A liquid crystal drive device having a differential-type input circuit including a differential amplification stage for receiving a differential signal and a buffer stage for generating an output signal on the basis of an output of the differential amplification stage, the liquid crystal drive device for receiving a signal of display data via the input circuit and outputting a signal for driving a liquid crystal panel on the basis of the display data, wherein a liquid crystal driving voltage VLCD larger than a power supply voltage VCC for logic to be supplied to the operation voltage buffer stage is supplied to the differential amplification stage of the input circuit. A standby function of interrupting an operation current of the differential amplification stage in a period where no display data is received is provided.Type: ApplicationFiled: August 3, 2007Publication date: December 6, 2007Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
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Publication number: 20070257942Abstract: A generation circuit generates gray scale voltages having a plurality of levels for positive polarity and gray scale voltages having a plurality of levels for negative polarity; wherein said generation circuit, in the mode in which the number of colors to be displayed on a display panel is small, decreases a current flowing into an internal circuit which generates a gray scale voltage of an intermediate level other than two gray scale voltages of a gray scale voltage of the most lowest level and a gray scale voltage of the most highest level among the gray scale voltages of said plurality of levels, in comparison to a current flowing in the other mode; and wherein said selection circuit, in the mode in which the number of colors to be displayed on said display panel is small, selects said gray scale voltage according to said display data, from the two gray scale voltages of said most lowest level gray scale voltage and said most highest level gray scale voltage which are generated from said generation circuitType: ApplicationFiled: July 11, 2007Publication date: November 8, 2007Inventors: Yasuyuki KUDO, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa