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).

  • Patent number: 9336733
    Abstract: 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: Grant
    Filed: January 21, 2014
    Date of Patent: May 10, 2016
    Assignee: Renesas Electronics Corporation
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
  • Publication number: 20140132494
    Abstract: 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: Application
    Filed: January 21, 2014
    Publication date: May 15, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Hiroki AIZAWA
  • Patent number: 8633881
    Abstract: 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: Grant
    Filed: February 14, 2012
    Date of Patent: January 21, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
  • Publication number: 20120139972
    Abstract: 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: Application
    Filed: February 14, 2012
    Publication date: June 7, 2012
    Inventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Hiroki AIZAWA
  • Patent number: 8120561
    Abstract: 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: Grant
    Filed: March 26, 2009
    Date of Patent: February 21, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
  • Patent number: 8094104
    Abstract: 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: Grant
    Filed: August 3, 2007
    Date of Patent: January 10, 2012
    Assignees: Hitachi ULSI Systems Co., Ltd., Renesas Electronics Corporation
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20110148953
    Abstract: 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: Application
    Filed: March 1, 2011
    Publication date: June 23, 2011
    Inventors: Yasuyuki KUDO, Akihito AKAI, Kazuo OOKADO, Kazunari KUROKAWA, Atsuhiro HIGA
  • Patent number: 7898555
    Abstract: 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 circuit
    Type: Grant
    Filed: July 11, 2007
    Date of Patent: March 1, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
  • Patent number: 7750882
    Abstract: 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: Grant
    Filed: January 26, 2006
    Date of Patent: July 6, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Akihito Akai, Yasuyuki Kudo, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
  • Publication number: 20090184985
    Abstract: 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: Application
    Filed: March 26, 2009
    Publication date: July 23, 2009
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
  • Patent number: 7511693
    Abstract: 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: Grant
    Filed: October 13, 2005
    Date of Patent: March 31, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Hiroki Aizawa
  • Patent number: 7480164
    Abstract: 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: Grant
    Filed: October 15, 2007
    Date of Patent: January 20, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
  • Patent number: 7450099
    Abstract: 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: Grant
    Filed: August 16, 2004
    Date of Patent: November 11, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Yasuyuki Kudo, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa
  • Patent number: 7405732
    Abstract: 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: Grant
    Filed: October 25, 2001
    Date of Patent: July 29, 2008
    Assignees: Renesas Technology Corp., Hitachi ULSI Systems Co., Ltd.
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20080049480
    Abstract: 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: Application
    Filed: October 15, 2007
    Publication date: February 28, 2008
    Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
  • Patent number: 7317627
    Abstract: 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: Grant
    Filed: May 8, 2007
    Date of Patent: January 8, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
  • Publication number: 20070279404
    Abstract: 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: Application
    Filed: August 3, 2007
    Publication date: December 6, 2007
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20070279357
    Abstract: 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: Application
    Filed: August 3, 2007
    Publication date: December 6, 2007
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20070279358
    Abstract: 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: Application
    Filed: August 3, 2007
    Publication date: December 6, 2007
    Inventors: Arata Kinjo, Kazuo Ookado, Kouichi Kotera, Hitoshi Oda, Masuhiro Endo
  • Publication number: 20070257942
    Abstract: 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 circuit
    Type: Application
    Filed: July 11, 2007
    Publication date: November 8, 2007
    Inventors: Yasuyuki KUDO, Akihito Akai, Kazuo Ookado, Kazunari Kurokawa, Atsuhiro Higa