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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Patent number: 6924868Abstract: 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: GrantFiled: October 23, 2001Date of Patent: August 2, 2005Assignees: Renesas Technology Corp., Hitachi Device Engineering Co., Ltd.Inventors: Kazuhisa Higuchi, Yoshikazu Yokota, Kimihiko Sugiyama
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Patent number: 6898096Abstract: 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: March 7, 2002Date of Patent: May 24, 2005Assignees: Renesas Technology Corp., Hitachi Device Engineering Co., Ltd.Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Publication number: 20050007326Abstract: 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: ApplicationFiled: August 9, 2004Publication date: January 13, 2005Inventors: Yasuyuki Kudo, Yoshikazu Yokota, Kazunari Kurokawa, Atsushiro Higa
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Publication number: 20040196236Abstract: 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: ApplicationFiled: April 14, 2004Publication date: October 7, 2004Inventors: Yasuyuki Kudo, Atsuhiro Higa, Yoshikazu Yokota, Hiroshi Kurihara, Kazunari Kurokawa
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Patent number: 6795047Abstract: 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 16, 2001Date of Patent: September 21, 2004Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Yoshikazu Yokota, Kazunari Kurokawa, Atsuhiro Higa
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Patent number: 6781590Abstract: A graphic processing system having a main memory for storing a program and information corresponding to pixels, a main processor for executing a program transferred from the main memory or from external to control the system, display/output devices for outputting graphic information attained by a control of pixels arranged in a plurality of dimensions, a frame buffer for storing information corresponding to pixels output to the display/output devices, and a graphic processor for receiving a command and parameter information from the main memory and/or the main processor, for generating character and graphic data in accordance with a predetermined processing procedure, and for performing a transfer control including an execution of a drawing processing to transfer generated data through first and second address buses and first and second data buses to the main memory and/or frame buffer.Type: GrantFiled: November 19, 2001Date of Patent: August 24, 2004Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.Inventors: Koyo Katsura, Shigeru Matsuo, Jun Sato, Takashi Sone, Yoshikazu Yokota, Masahiko Kikuchi
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Publication number: 20040160398Abstract: 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: February 17, 2004Publication date: August 19, 2004Applicants: Renesas Technology Corp., Hitachi Device Engineering Co., Ltd.Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Patent number: 6753880Abstract: 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: September 24, 2001Date of Patent: June 22, 2004Assignee: Hitachi, Ltd.Inventors: Yasuyuki Kudo, Atsuhiro Higa, Yoshikazu Yokota, Hiroshi Kurihara, Kazunari Kurokawa
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Patent number: 6747628Abstract: 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: October 25, 2002Date of Patent: June 8, 2004Assignees: Renesas Technology Corp., Hitachi Device Engineering Co., Ltd.Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Patent number: 6633274Abstract: 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: July 21, 2000Date of Patent: October 14, 2003Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Publication number: 20030169244Abstract: 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: February 26, 2003Publication date: September 11, 2003Applicant: Hitachi, Ltd.Inventors: Yasuhito Kurokawa, Shigeru Ohta, Kunihiko Tani, Goro Sakamaki, Yoshikazu Yokota
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Publication number: 20030103018Abstract: 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: October 25, 2002Publication date: June 5, 2003Applicant: Hitachi, Ltd.Inventors: Yoshikazu Yokota, Kunihiko Tani, Gorou Sakamaki, Katsuhiko Yamamoto, Takashi Yoneoka, Kazuhisa Higuchi, Kimihiko Sugiyama
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Publication number: 20030001850Abstract: A graphic processing system having a main memory for storing a program and information corresponding to pixels, a main processor for executing a program transferred from the main memory or from external to control the system, display/output devices for outputting graphic information attained by a control of pixels arranged in a plurality of dimensions, a frame buffer for storing information corresponding to pixels output to the display/output devices, and a graphic processor for receiving a command and parameter information from the main memory and/or the main processor, for generating character and graphic data in accordance with a predetermined processing procedure, and for performing a transfer control including an execution of a drawing processing to transfer generated data through first and second address buses and first and second data buses to the main memory and/or frame buffer.Type: ApplicationFiled: November 19, 2001Publication date: January 2, 2003Inventors: Koyo Katsura, Shigeru Matsuo, Jun Sato, Takashi Sone, Yoshikazu Yokota, Masahiko Kikuchi
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Publication number: 20020145599Abstract: 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: March 7, 2002Publication date: October 10, 2002Inventors: Kazuya Endo, Naoki Miyamoto, Toshio Mizuno, Takayuki Nakaji, Takatoshi Uchida, Kazuo Ookado, Yoshikazu Yokota
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Publication number: 20020145581Abstract: 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: ApplicationFiled: September 24, 2001Publication date: October 10, 2002Inventors: Yasuyuki Kudo, Atsuhiro Higa, Yoshikazu Yokota, Hiroshi Kurihara, Kazunari kurokawa
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Publication number: 20020109653Abstract: 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: ApplicationFiled: August 16, 2001Publication date: August 15, 2002Inventors: Yasuyuki Kudo, Yoshikazu Yokota, Kazunari Kurokawa, Atsuhiro Higa
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Patent number: 6429871Abstract: A graphic processing method and system which is capable of displaying a combination of images from, for example, an external source such as TV signals and graphic data generated by a graphic processor, whereby the graphic processor fetches horizontal synchronizing signals and vertical synchronizing signals, via respective terminals, from a source external of the system, and reads out the data from a frame buffer in accordance with the fetched signals to display the data.Type: GrantFiled: August 29, 1997Date of Patent: August 6, 2002Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd.Inventors: Koyo Katsura, Shigeru Matsuo, Jun Sato, Takashi Sone, Yoshikazu Yokota, Masahiko Kikuchi
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Publication number: 20020075272Abstract: The display RAM built into a conventional display control device uses a system in which data are sequentially written word by word, it involves a problem that, if th write speed is to be raised to match the transfer speed of display data from the microprocessor, the power consumption will increase in proportion to the transfer speed. The width (number of bits) of write data to a display RAM in a display control device is set to be an integral multiple of the width of write data supplied from an external microprocessor or the like, and two stages of latch circuits for holding write data equivalent to one row of the display RAM are provided.Type: ApplicationFiled: December 3, 2001Publication date: June 20, 2002Applicant: Hitachi, Ltd.Inventors: Kunihiko Tani, Yoshikazu Yokota, Goro Sakamaki, Takashi Ohyama
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Patent number: 6396464Abstract: The liquid-crystal display control apparatus provided by the present invention comprises a display RAM unit 21 for storing character codes, character-generator RAM and ROM units 22 and 23 for storing character font patterns and a segment RAM unit 24 for storing picture patterns such as marks and icons. When displaying a character, the following display control is carried out. First of all, a character code is read out from the display RAM unit 21 at a display address generated by a display-address counter 25. The character code is then used in conjunction with a raster address output by a line-address counter 26 for reading out a character font pattern from the character-generator RAM unit 22 or the character-generator ROM unit 23. When displaying a picture pattern such as a mark or an icon, on the other hand, the following display control is carried out. Display control information is read out from the segment RAM unit 24 at an address generated by the display-address counter 25.Type: GrantFiled: June 29, 2001Date of Patent: May 28, 2002Assignees: Hitachi, Ltd., Hitachi Device Engineering Co., Ltd.Inventors: Yoshikazu Yokota, Satoru Tsunekawa, Kimihiko Sugiyama
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Publication number: 20020021399Abstract: 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: October 23, 2001Publication date: February 21, 2002Applicant: Hitachi, Ltd.Inventors: Kazuhisa Higuchi, Yoshikazu Yokota, Kimihiko Sugiyama