Patents by Inventor Hitoshi Hirakawa

Hitoshi Hirakawa 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: 6900797
    Abstract: A progressive display is realized that has an electrode structure in which two neighboring rows share a display electrode. A PDP has display electrodes arranged so that two neighboring rows share one electrode for display, and the display electrodes crosses an address electrode in each column. A row selection is performed by temporarily biasing one display electrode Yj of the electrode pair corresponding to the selected row to the selecting potential Vy, while an addressing is performed by controlling the potential of the address electrode Ak in accordance with the display data. At that time, the cell-selecting voltage Vay that is applied to the interelectrode AY between the display electrode Yj and the address electrode Ak made lower than the discharge starting voltage VAY of the interelectrode AY.
    Type: Grant
    Filed: January 30, 2001
    Date of Patent: May 31, 2005
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Hitoshi Hirakawa, Takashi Shiizaki, Tatsuhiko Kawasaki, Satoru Nishimura
  • Publication number: 20050088091
    Abstract: A gas-discharge tube has a glass tube as its main body and a trench is provided in the axial direction of the glass tube on one surface (the surface opposed to the discharge surface) among the external surfaces of the glass tube. An address electrode is placed in the trench. The inner surface of the region of the glass tube where sustain electrodes are placed is formed to have a microscopic unevenness. A secondary electron emission film is formed on this inner surface where the unevenness is formed. In addition, a phosphor support member, whose cross section across the axis is in approximately a C-shape and where a phosphor layer has been formed in advance on the inner surface, is placed inside of the glass tube. Stable discharge characteristics is obtained by eliminating dispersion of the position of an electrode, relative to the gas-discharge tube.
    Type: Application
    Filed: February 26, 2004
    Publication date: April 28, 2005
    Applicant: FUJITSU LIMITED
    Inventors: Akira Tokai, Hitoshi Yamada, Manabu Ishimoto, Kenji Awamoto, Yosuke Yamazaki, Hitoshi Hirakawa, Akira Nakazawa, Koji Shinohe
  • Publication number: 20050052353
    Abstract: A method of driving a plasma display panel, which includes controlling a charge state of a first display line being one of the two adjacent display lines utilizing the same single scan electrode, such that address discharge is not generated and controlling a charge state of a second display line being the other of the two adjacent display lines, such that address discharge can be generated, and then generating address discharge in the second display line, controlling the charge state of the second display line such that address discharge is not generated and controlling the charge state of the first display line such that the address discharge can be generated, and then generating address discharge in the first display line, and generating surface discharge simultaneously in the first and second display lines, thereby to achieve progressive display.
    Type: Application
    Filed: June 23, 2004
    Publication date: March 10, 2005
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Takashi Shiizaki, Hitoshi Hirakawa
  • Publication number: 20040257309
    Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.
    Type: Application
    Filed: June 14, 2004
    Publication date: December 23, 2004
    Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Naboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
  • Publication number: 20040234902
    Abstract: A plasma display panel in which projections are formed in grooves between partitions and phosphor layers are provided on the projections so as to increase the area where phosphor adheres and thereby to increase the luminance. A couple of substrates are opposed to each other to form a discharge space. Band-like partitions partitioning the discharge space are arranged on the back or front substrate. Wall-like projections lower than the partitions and high enough to increase the area where phosphor layers are formed are provided in the region where the discharge space is formed in the long grooves between the partitions or around the discharge space. Phosphor layers are formed in the grooves between the partitions including the wall-like projections. A method for producing such a plasma display panel is also disclosed.
    Type: Application
    Filed: March 29, 2004
    Publication date: November 25, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Osamu Toyoda, Akira Tokai, Kazunori Inoue, Fumihiro Namiki, Saburou Morita, Yojiro Shimada, Hitoshi Hirakawa, Takashi Katayama
  • Patent number: 6781564
    Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.
    Type: Grant
    Filed: December 17, 2002
    Date of Patent: August 24, 2004
    Assignees: Hitachi, Ltd., Fujitsu Limited
    Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
  • Publication number: 20040125051
    Abstract: A method for driving a plasma display panel, wherein a display field, corresponding to a display of a screen, is composed of a plurality of subfields, a gradation display is realized by combining subfields to be lit among the plurality of subfields, cells to be lit in the display field are separated from unlit cells and all of the cells to be lit are lit in a predetermined subfield arranged near the head in the display field. The gradation display level is set with the light emission in the predetermined subfield being taken into consideration.
    Type: Application
    Filed: September 15, 2003
    Publication date: July 1, 2004
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Hitoshi Hirakawa, Shinsuke Tanaka, Takashi Shiizaki, Satoru Nishimura, Yoshikazu Kanazawa
  • Patent number: 6713959
    Abstract: A plasma display panel and method of producing same, in which projections are formed in grooves between partitions and phosphor layers are provided on the projections so as to increase the area where phosphor adheres and thereby to increase the luminance. A pair of substrates, opposed to each other, form a discharge space. Band-like partitions partitioning the discharge space are arranged on one of the back and front substrates. Wall-like projections, lower than the partitions but high enough to increase the area where phosphor layers are formed, are provided in the region where the discharge space is formed in the long grooves between the partitions or around the discharge space. Phosphor layers are formed in the grooves between the partitions including the wall-like projections.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: March 30, 2004
    Assignee: Fujitsu Limited
    Inventors: Osamu Toyoda, Akira Tokai, Kazunori Inoue, Fumihiro Namiki, Saburou Morita, Yojiro Shimada, Hitoshi Hirakawa, Takashi Katayama
  • Publication number: 20040012546
    Abstract: A driving circuit of a plasma display panel is provided in which a display cell including a first electrode and a second electrode is selected to light up, for applying a first voltage Vs1 to the first electrode and a second voltage Vs2 to the second electrode adjacent to the first electrode to cause a sustain discharge between the first and second electrodes. The driving circuit generates a sustain discharge voltage such that, during the sustain discharge between the first and second electrodes, an applied voltage Vc to a third electrode adjacent to the first electrode opposite to the second electrode falls within a range Vs2≦Vc<Vs1, and, in this case, when a display cell including the third electrode is selected to light up, the polarity of a wall charge formed on the third electrode becomes positive.
    Type: Application
    Filed: May 19, 2003
    Publication date: January 22, 2004
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Akihiro Takagi, Takashi Shiizaki, Takayuki Shimizu, Noriaki Setoguchi, Hitoshi Hirakawa, Tomokatsu Kishi
  • Publication number: 20030218581
    Abstract: A driving method of a plasma display panel is provided in which effective resolution and luminance in a display of fields that constitute a frame are improved. The method includes dividing each of M (M≧2) fields that constitute a frame into K (K≧2) subfields having luminance weight, displaying the k (1≦k<K) subfields selected in descending order of the luminance weight in progressive format using all display lines out of the K subfields and displaying the remaining subfields in interlaced format using the display lines selected at regular intervals at a ratio of one per M display lines in arrangement order.
    Type: Application
    Filed: February 11, 2003
    Publication date: November 27, 2003
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Yoshimi Kawanami, Yasuhiko Kunii, Hitoshi Hirakawa, Takashi Shiizaki
  • Publication number: 20030201953
    Abstract: A driving method, able to realize a PDP device having a reduced background luminance and high display quality, has been disclosed.
    Type: Application
    Filed: April 2, 2003
    Publication date: October 30, 2003
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Takashi Shiizaki, Hitoshi Hirakawa, Eiji Ito, Shinsuke Tanaka, Satoru Nishimura
  • Publication number: 20030122737
    Abstract: A display apparatus includes a display panel including address electrodes and sustain electrodes crossing the address electrodes, with pixels being sandwiched between the address electrodes and the sustain electrodes. A sustain-electrode drive circuit selectively generates both sustain pulses and scan pulses and supplies them to the sustain electrodes. An address-electrode drive circuit generates address pulses based on a video signal and supplies the address pulses to the address electrodes. A control-signal generation circuit generates a control signal for controlling the sustain-electrode drive circuit to generate a selected one of the sustain pulses and the scan pulses and supplies the control signal to the sustain-electrode drive circuit. In order to display an image on the display panel, the sustain-electrode drive circuit both specifies addresses of pixels to be turned on and turns on the pixels at the specified addresses.
    Type: Application
    Filed: December 17, 2002
    Publication date: July 3, 2003
    Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
  • Publication number: 20020190930
    Abstract: A method of driving a plasma display panel, which includes controlling a charge state of a first display line being one of the two adjacent display lines utilizing the same single scan electrode, such that address discharge is not generated and controlling a charge state of a second display line being the other of the two adjacent display lines, such that address discharge can be generated, and then generating address discharge in the second display line, controlling the charge state of the second display line such that address discharge is not generated and controlling the charge state of the first display line such that the address discharge can be generated, and then generating address discharge in the first display line, and generating surface discharge simultaneously in the first and second display lines, thereby to achieve progressive display.
    Type: Application
    Filed: November 13, 2001
    Publication date: December 19, 2002
    Applicant: Fujitsu Hitachi Plasma Display Limited
    Inventors: Takashi Shiizaki, Hitoshi Hirakawa
  • Patent number: 6496166
    Abstract: As is obvious from the description in the specification and the attached drawings, the present invention provides a display apparatus for displaying an image on a display panel by turning on pixels of said display panel, said display apparatus comprising: a display panel provided with: address electrodes driven by address pulses based on a video input signal; and sustain electrodes crossing said address electrodes and sandwiching electrical discharging units of pixels with said address electrodes and driven by sustain pulses; a sustain-electrode drive circuit for generating said sustain pulses and scan pulses, provided with a common circuit for generating said sustain pulses or said scan pulses in response to an operating state thereof and for supplying said scan pulses and said sustain pulses to said sustain electrodes.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: December 17, 2002
    Assignees: Hitachi, Ltd., Fujitsu Limited
    Inventors: Makoto Onozawa, Yuji Sano, Michitaka Ohsawa, Takashi Sasaki, Noboru Akiyama, Fumitaka Asami, Kazuo Yoshiikawa, Hitoshi Hirakawa, Tomokatsu Kishi, Toyoshi Kawada
  • Publication number: 20020105485
    Abstract: A driving method of a plasma display panel having a display electrodes arranged at the ratio of three per two rows is provided, in which all rows are lighted in sustaining period from an addressing period to the next addressing period and electromagnetic interference is reduced sufficiently. A display discharge is generated by controlling potentials of the display electrodes so as to satisfy two conditions. One condition is that there is a pair of display electrodes having terminals at the same side of the display screen and current directions opposite to each other. Another condition is to generate a potential difference across the display electrodes, which is necessary for discharging. Magnetic fields are canceled by each other in the pair of electrodes having current directions opposite to each other, so that electromagnetic interference is reduced.
    Type: Application
    Filed: June 21, 2001
    Publication date: August 8, 2002
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Takashi Shiizaki, Hitoshi Hirakawa
  • Publication number: 20020070906
    Abstract: A plasma display panel and a method of driving the same are provided in which circuit elements necessary for controlling potentials of scan electrodes can be reduced without using a complicated multilayered wiring. In the plasma display panel, k (k≧2) data electrodes, each of which is continuous from one end of a column to the other end, are arranged for each column of a matrix display. All scan electrodes in a display screen are classified into k groups, and one of k groups is assigned to k data electrodes in each column. Each data electrode is crossed with or opposed to scan electrodes belonging to the group that is assigned to the data electrode without overlapping a partition in a plan view and is crossed with or opposed to other scan electrodes with overlapping the partition.
    Type: Application
    Filed: April 25, 2001
    Publication date: June 13, 2002
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Tatsuhiko Kawasaki, Hitoshi Hirakawa, Takashi Shiizaki, Takashi Sasaki
  • Publication number: 20020067321
    Abstract: A display panel has a plurality of first electrodes, a plurality of second electrodes disposed adjacently and alternately with the first electrodes, a plurality of third electrodes formed to cross the first and second electrodes, and a control circuit for carrying out an address discharge during the second electrodes and the third electrodes. The control circuit carries out a sustain discharge to decrease the volume of wall charges, accumulated on a display cell in which a sustain discharge is not intended, to a level which cannot generate a sustain discharge.
    Type: Application
    Filed: December 3, 2001
    Publication date: June 6, 2002
    Inventors: Yoshikazu Kanazawa, Hitoshi Hirakawa, Shigeharu Asao, Shinsuke Tanaka
  • Patent number: 6400342
    Abstract: A method for driving an plasma display panel according to the present invention uses an erase addressing for matrix display by an AC-driven plasma display panel. The method includes the steps of grouping the electrode pairs, which define rows, into a first group and a second group, and, as an operation to charge all the cells prior to the addressing, applying, to electrode pairs belonging to either one of the first and second groups, a first voltage for generating a discharge only in cells in a non-charged state and then a second voltage for generating a discharge in all the cells, and applying the second voltage to electrode pairs belonging to the other group.
    Type: Grant
    Filed: April 29, 1998
    Date of Patent: June 4, 2002
    Assignee: Fujitsu Limited
    Inventor: Hitoshi Hirakawa
  • Publication number: 20020039086
    Abstract: A progressive display is realized that has an electrode structure in which two neighboring rows share a display electrode. A PDP has display electrodes arranged so that two neighboring rows share one electrode for display, and the display electrodes crosses an address electrode in each column. A row selection is performed by temporarily biasing one display electrode Yj of the electrode pair corresponding to the selected row to the selecting potential Vy, while an addressing is performed by controlling the potential of the address electrode Ak in accordance with the display data. At that time, the cell-selecting voltage Vay that is applied to the interelectrode AY between the display electrode Yj and the address electrode Ak made lower than the discharge starting voltage VAY of the interelectrode AY.
    Type: Application
    Filed: January 30, 2001
    Publication date: April 4, 2002
    Inventors: Hitoshi Hirakawa, Takashi Shiizaki, Tatsuhiko Kawasaki, Satoru Nishimura
  • Patent number: 6278422
    Abstract: In a method of driving a plasma display panel to display gradation, a field includes a plurality of subfields, the subfields of each field are separated into a plurality of subfield groups, and each subfield is weighted in brightness in such a manner that the subfields in the subfield group are all equal in weight. An address period and a sustain period are allocated to each subfield. In at least one subfield group, a number of times of sustaining discharge for a subfield to be sustained independently is set different from a number of times of sustaining discharge for at least one other subfield.
    Type: Grant
    Filed: March 31, 1999
    Date of Patent: August 21, 2001
    Assignee: Fujitsu Limited
    Inventors: Yoshitaka Ukai, Hitoshi Hirakawa