Patents by Inventor Yoshikazu Yokota
Yoshikazu Yokota 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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Publication number: 20090085857Abstract: The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.Type: ApplicationFiled: October 13, 2008Publication date: April 2, 2009Applicant: Renesas Technology CorporationInventors: Yasuyuki Kudo, Tsutomu Furuhashi, Yoshikazu Yokota, Toshimitsu Matsudo, Atsuhiro Higa
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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: 7453433Abstract: The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.Type: GrantFiled: June 29, 2005Date of Patent: November 18, 2008Assignee: Renesas Technology Corp.Inventors: Yasuyuki Kudo, Tsutomu Furuhashi, Yoshikazu Yokota, Toshimitsu Matsudo, Atsuhiro Higa
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Patent number: 7355596Abstract: A matrix type liquid crystal display device has a function of suppressing power consumption without calling for an extra circuit arrangement such as the arrangement of storage capacitance and wiring to storage capacitance and without disposing new external components. A switch is disposed in the liquid crystal display device to temporarily short-circuit both column electrodes and common electrodes sandwiching a liquid crystal between them in synchronism with an alternation timing.Type: GrantFiled: August 9, 2004Date of Patent: April 8, 2008Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Yoshikazu Yokota, Kazunari Kurokawa, Atsushiro Higa
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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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Patent number: 7286110Abstract: In conventional liquid crystal display controllers such as for portable telephone sets, the display is reduced in the stand-by state but the liquid crystal display duty is not changed, i.e., even the common electrodes of the rows that are not producing display are scanned, and the consumption of electric power is not decreased to a sufficient degree in the stand-by state. A liquid crystal display controller (2) includes a drive duty selection register (34) capable of being rewritten by a microprocessor (1), and a drive bias selection register (32). When the display is changed from the whole display on a liquid crystal display panel (3) to a partial display on part of the rows only, the preset values of the drive duty selection register and of the drive bias selection register are changed, so that the display is selectively produced on a portion of the liquid crystal display panel at a low voltage with a low-duty drive.Type: GrantFiled: February 17, 2004Date of Patent: October 23, 2007Assignee: Renesas Technology Corp.Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Publication number: 20070211508Abstract: 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: May 8, 2007Publication date: September 13, 2007Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Patent number: 7233511Abstract: 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: August 14, 2006Date of Patent: June 19, 2007Assignee: Renesas Technology Corp.Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Publication number: 20070085793Abstract: A display device for displaying display data includes a display panel having pixel sections in a matrix form, a scanning circuit which selects a line of the pixel sections, a generation circuit which generates a plurality of gray-scale voltages based on a reference voltage, and a selection circuit which selects a gray-scale voltage corresponding to the display data from the plurality of gray-scale voltages, and outputs the gray-scale voltage thus selected to a pixel section of the display panel. The generation circuit one of increases and decreases a steady-state current of the generation circuit at a second period within one scanning period of the scanning circuit.Type: ApplicationFiled: December 12, 2006Publication date: April 19, 2007Inventors: Yasuyuki Kudo, Atsuhiro Higa, Yoshikazu Yokota, Hiroshi Kurihara, Kazunari Kurokawa
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Publication number: 20070052654Abstract: In conventional liquid crystal display controllers such as for portable telephone sets, the display is reduced in the stand-by state but the liquid crystal display duty is not changed, i.e., even the common electrodes of the rows that are not producing display are scanned, and the consumption of electric power is not decreased to a sufficient degree in the stand-by state. A liquid crystal display controller (2) includes a drive duty selection register (34) capable of being rewritten by a microprocessor (1), and a drive bias selection register (32). When the display is changed from the whole display on a liquid crystal display panel (3) to a partial display on part of the rows only, the preset values of the drive duty selection register and of the drive bias selection register are changed, so that the display is selectively produced on a portion of the liquid crystal display panel at a low voltage with a low-duty drive.Type: ApplicationFiled: November 8, 2006Publication date: March 8, 2007Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Publication number: 20070035503Abstract: There is provided a display driver control circuit which is just suitable for display drive including display with a small amount of change and display with a large amount of change and can realize saving of chip area and reduction of power consumption and cost. In this display driver control circuit, memory capacity of an internal display memory is set smaller than amount of data of one display picture of a display panel as the drive object, and the display data can be transferred with the system in which externally inputted display data is once stored in the display memory and is then sent of a drive circuit to output a drive signal and with the system in which the display data is sent in direct to the drive circuit by way of no display memory to output a drive signal. Moreover, both transfer methods can be executed on the time division basis.Type: ApplicationFiled: October 24, 2006Publication date: February 15, 2007Inventors: Yasuhito Kurokawa, Shigeru Ohta, Kunihiko Tani, Goro Sakamaki, Yoshikazu Yokota
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Patent number: 7151549Abstract: A display device or a display driving device includes a display memory for storing display data; a histogram memory for storing frequencies of gray-scale voltages every line; a gray-scale voltage generation circuit for generating a plurality of gray-scale voltages on the basis of reference voltages, a current quantity of a circuit for generating each of the plurality of gray-scale voltages being changed according to a frequency of the gray-scale voltage; and a voltage selector section for selecting a gray-scale voltage to be applied to each of the plurality of pixel sections, from the plurality of gray-scale voltages.Type: GrantFiled: April 14, 2004Date of Patent: December 19, 2006Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Atsuhiro Higa, Yoshikazu Yokota, Hiroshi Kurihara, Kazunari Kurokawa
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Publication number: 20060274015Abstract: 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: August 14, 2006Publication date: December 7, 2006Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Patent number: 7145541Abstract: There is provided a display driver control circuit which is just suitable for display drive including display with a small amount of change and display with a large amount of change and can realize saving of chip area and reduction of power consumption and cost. In this display driver control circuit, memory capacity of an internal display memory is set smaller than amount of data of one display picture of a display panel as the drive object, and the display data can be transferred with the system in which externally inputted display data is once stored in the display memory and is then sent of a drive circuit to output a drive signal and with the system in which the display data is sent in direct to the drive circuit by way of no display memory to output a drive signal. Moreover, both transfer methods can be executed on the time division basis.Type: GrantFiled: February 26, 2003Date of Patent: December 5, 2006Assignee: Renesas Technology Corp.Inventors: Yasuhito Kurokawa, Shigeru Ohta, Kunihiko Tani, Goro Sakamaki, Yoshikazu Yokota
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Patent number: 7110274Abstract: 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: January 12, 2005Date of Patent: September 19, 2006Assignee: Renesas Technology Corp.Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Patent number: 7068253Abstract: The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.Type: GrantFiled: June 25, 2001Date of Patent: June 27, 2006Assignee: Renesas Technology CorporationInventors: Yasuyuki Kudo, Tsutomu Furuhashi, Yoshikazu Yokota, Toshimitsu Matsudo, Atsuhiro Higa
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Publication number: 20050280623Abstract: A display control device and technique for controlling displays on a display unit, in which a plurality of display segments are two-dimensionally arranged (e.g. a dot matrix type display unit), is provided. The technique is effectively applicable to a write data latch circuit of a memory for storing display data in the display control device, such as, for example, a liquid crystal display control device, a mobile electronic apparatus, etc. A display drive control technique for controlling a moving picture display mode of a display device is also provided. The display drive control circuit controls a picture display mode of a display device for displaying still pictures and moving pictures to a liquid crystal display device, such as, for example, a dot matrix type display devices, an organic EL display device, etc.Type: ApplicationFiled: January 7, 2005Publication date: December 22, 2005Inventors: Kunihiko Tani, Yoshikazu Yokota, Goro Sakamaki, Takashi Ohyama, Shigeru Ohta, Kei Tanabe
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Publication number: 20050243051Abstract: The present invention provides a liquid crystal display controller device and method which provides for a full and/or partial display with good display quality and/or low power consumption based on the scanning period for an active scan line being dependent upon a number of reference clock pulses. Some embodiments of the present invention include one or more of the following features: keeping the frequency substantially constant for different numbers of active scan lines, allowing change of the frequency due to characteristics of the LCD, displaying gradation with near linear effective voltage characteristics, displaying graduation data with lower power, or displaying a partial or full screen in a mobile device, for example, a cell phone.Type: ApplicationFiled: June 29, 2005Publication date: November 3, 2005Applicant: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Tsutomu Furuhashi, Yoshikazu Yokota, Toshimitsu Matsudo, Atsuhiro Higa
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Publication number: 20050174522Abstract: A liquid crystal display device comprises a liquid crystal display panel and a semiconductor integrated circuit for driving and controlling the liquid crystal display panel. The number of input/output wires connected to I/O terminals (bonding pads) of the semiconductor integrated circuit is reduced so as to simplify wiring patterns of the I/O wires, whereby degrees of freedom in arranging the I/O wiring patterns are enhanced. The panel has a pair of insulating substrate, and the semiconductor integrated circuit is mounted on one of the paired substrates. The semiconductor integrated circuit has a mode terminal which is fixed to a power supply potential or to a reference potential during operation of the integrated circuit, and power supply dummy terminals connected to the power supply potential or reference potential inside the semiconductor integrated circuit. The wiring patterns formed on the paired insulating substrates connect the mode terminal to the power supply dummy terminals.Type: ApplicationFiled: April 6, 2005Publication date: August 11, 2005Inventors: Kazuhisa Higuchi, Yoshikazu Yokota, Kimihiko Sugiyama