Patents by Inventor Keiji Akamatsu
Keiji Akamatsu 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: 8508437Abstract: A plasma display device has a crystal particle made of MgO single crystal where the cathode luminescence emission spectrum exhibits a desired characteristic, and displays an image by a driving method in the initializing period. The initializing period has the first half for applying the voltage, which gradually increases from a first voltage and to a second voltage, to a second electrode, and the latter half for applying the voltage, which gradually decreases from a third voltage and to a fourth voltage.Type: GrantFiled: April 13, 2009Date of Patent: August 13, 2013Assignee: Panasonic CorporationInventors: Mitsuhiro Murata, Takuji Tsujita, Masaharu Terauchi, Toshikazu Wakabayashi, Hiroshi Asano, Shinichiro Hashimoto, Keiji Akamatsu
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Patent number: 8482490Abstract: In a plasma display device, a plurality of agglomerated particle groups in which a plurality of crystal particles made of a metal oxide agglomerate are disposed in the periphery of a protective layer thereof. The plasma display device is driven by the following driving method to display images. An initializing period has a first half of the initializing period in which a second electrode is applied with a voltage gradually rising from a first voltage to a second voltage, and a second half of the initializing period in which the second electrode is applied with a voltage gradually falling from a third voltage to a fourth voltage.Type: GrantFiled: March 27, 2009Date of Patent: July 9, 2013Assignee: Panasonic CorporationInventors: Mitsuhiro Murata, Kaname Mizokami, Toshikazu Wakabayashi, Shinichiro Hashimoto, Keiji Akamatsu
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Patent number: 8384622Abstract: The total number of the scan electrodes is divided into a first scan electrode group and a second scan electrode group. The first scan electrode group drive section for driving the first scan electrode group produces a selection potential and a non-selection potential in the scan period, and supplies scan pulses based on the two potentials in the first half of the scan period. The complex switch section supplies the selection potential produced using the first scan electrode group drive section to the second scan electrode group drive section for driving the second scan electrode group in the latter half of the scan period. The second scan electrode group drive section supplies scan pulses based on the input selection potential.Type: GrantFiled: December 20, 2007Date of Patent: February 26, 2013Assignee: Panasonic CorporationInventors: Yasuhiro Arai, Keiji Akamatsu, Toshikazu Wakabayashi, Mitsuhiro Murata
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Publication number: 20120280963Abstract: The present invention allows a plasma display apparatus having a high-luminance panel to decrease initializing bright points that easily occur just after power-on of the apparatus, enhancing the quality of display image. The panel has discharge cells, each of which including a data electrode, and a display electrode pair formed of a scan electrode and a sustain electrode. In the driving method of the panel, one field period is formed of subfields, each of which including an initializing period for generating initializing discharge in the discharge cells, an address period for applying scan pulses to the scan electrodes and applying address pulses to the data electrodes, and a sustain period for applying sustain pulses to the data electrode pairs. In the structure above, a predetermined period after power-off of the apparatus has no generation of the address pulses, the scan pulses, and the sustain pulses.Type: ApplicationFiled: January 19, 2011Publication date: November 8, 2012Inventors: Keiji Akamatsu, Yuichi Sakai, Minoru Takeda, Hidehiko Shoji, Naoyuki Tomioka
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Patent number: 8232983Abstract: In the method for driving a plasma display panel and the plasma display device, the scan electrodes of the plasma display panel are divided into two scan electrode groups, the address period of subfields is divided into two address periods corresponding to the two scan electrode groups, and at least in one address period, the scan electrodes belonging to the scan electrode group provided with scan pulses are sequentially provided with scan pulses shifting from second voltage higher than scan pulse voltage to scan pulse voltage and shifting again to second voltage, and the scan electrodes belonging to the scan electrode group not provided with scan pulses are provided with either third voltage higher than scan pulse voltage or fourth voltage higher than second voltage and third voltage, and with third voltage at least while scan pulse voltage is applied to adjacent scan electrodes.Type: GrantFiled: March 27, 2008Date of Patent: July 31, 2012Assignee: Panasonic CorporationInventors: Kenji Ogawa, Keiji Akamatsu, Yasuhiro Arai
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Patent number: 8212746Abstract: In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an initializing period for causing initializing discharge in a discharge cell, an address period for selectively causing address discharge in the discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. A holding period when discharge is not caused is disposed before the head subfield belonging to at least one subfield group of the plurality of subfield groups. In the initializing period of the head subfield belonging to at least one subfield group, an initializing operation of causing initializing discharge is performed in the discharge cell where the sustain discharge has been performed in the sustain period of the immediately preceding subfield.Type: GrantFiled: April 10, 2008Date of Patent: July 3, 2012Assignee: Panasonic CorporationInventors: Keiji Akamatsu, Minoru Takeda, Kenji Ogawa, Hiroshi Ibaraki
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Patent number: 8212745Abstract: In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an address period for selectively causing address discharge in a discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. In the discharge cell for causing address discharge in a certain subfield other than the head subfield in each subfield group, address discharge is caused even in the head subfield.Type: GrantFiled: April 10, 2008Date of Patent: July 3, 2012Assignee: Panasonic CorporationInventors: Minoru Takeda, Kenji Ogawa, Keiji Akamatsu
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Patent number: 8207913Abstract: A plasma display panel; a scan electrode drive circuit for generating a gently decreasing downward inclined waveform voltage in an initializing period, a gently increasing first inclined waveform voltage, and a second inclined waveform voltage having a steeper gradient than the first inclined waveform voltage and decreasing immediately after the increasing waveform voltage reaches a predetermined potential in the last part of the sustain period. The lowest voltage in the downward inclined waveform voltage is switched at a first voltage, a second voltage higher than the first voltage and a third voltage higher than the second voltage to generate a downward inclined waveform voltage. The lowest voltage is switched according to the detected temperature to generate the downward inclined waveform voltage.Type: GrantFiled: April 23, 2008Date of Patent: June 26, 2012Assignee: Panasonic CorporationInventors: Hiroshi Ibaraki, Minoru Takeda, Keiji Akamatsu, Kenji Ogawa, Nobuhiko Nakamura
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Publication number: 20120075283Abstract: In a driving method for a plasma display panel, in the initializing period in at least one of a plurality of subfields, selective initializing operation is performed that selectively causes initializing discharge only in a discharge cell having undergone address discharge in an immediately preceding address period. The selective initializing operation includes the step of applying first voltage to the sustain electrode and applying an up-ramp waveform voltage to the scan electrode, the step of applying a first down-ramp waveform voltage to the scan electrode and then applying a positive rectangular voltage to it, and the step of applying second voltage higher than the first voltage to the sustain electrode and applying a second down-ramp waveform voltage to the scan electrode.Type: ApplicationFiled: June 7, 2010Publication date: March 29, 2012Applicant: Panasonic CorporationInventors: Yutaka Yoshihama, Kenji Ogawa, Takateru Sawada, Toshiyuki Maeda, Keiji Akamatsu
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Publication number: 20120050253Abstract: An unnecessary discharge caused in the discharge cells in an initializing operation is prevented. This reduces the luminance of black level in a display image and stabilizes the address discharge at the same time, thus enhancing the image display quality. A plasma display panel that has a plurality of discharge cells having data electrodes and display electrode pairs, each formed of a scan electrode and a sustain electrode, is driven for gradation display such that a plurality of subfields is set in one field and each of the subfields has an initializing period, an address period, and a sustain period. For the above purpose, in the driving method for the plasma display panel, the following operations are performed. In the address period of a predetermined subfield, after the application of a scan pulse to all the scan electrodes is completed, a ramp voltage gently falling from a first voltage is applied to the sustain electrodes.Type: ApplicationFiled: May 13, 2010Publication date: March 1, 2012Applicant: PANASONIC CORPORATIONInventors: Yuichi Sakai, Kenji Ogawa, Yutaka Yoshihama, Keiji Akamatsu
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Publication number: 20110001425Abstract: In a plasma display device, a plurality of agglomerated particle groups in which a plurality of crystal particles made of a metal oxide agglomerate are disposed in the periphery of a protective layer thereof. The plasma display device is driven by the following driving method to display images. An initializing period has a first half of the initializing period in which a second electrode is applied with a voltage gradually rising from a first voltage to a second voltage, and a second half of the initializing period in which the second electrode is applied with a voltage gradually falling from a third voltage to a fourth voltage.Type: ApplicationFiled: March 27, 2009Publication date: January 6, 2011Inventors: Mitsuhiro Murata, Kaname Mizokami, Toshikazu Wakabayashi, Shinichiro Hashimoto, Keiji Akamatsu
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Publication number: 20100177084Abstract: A plasma display device has a crystal particle made of MgO single crystal where the cathode luminescence emission spectrum exhibits a desired characteristic, and displays an image by a driving method in the initializing period. The initializing period has the first half for applying the voltage, which gradually increases from a first voltage and to a second voltage, to a second electrode, and the latter half for applying the voltage, which gradually decreases from a third voltage and to a fourth voltage.Type: ApplicationFiled: April 13, 2009Publication date: July 15, 2010Applicant: PANASONIC CORPORATIONInventors: Mitsuhiro Murata, Takuji Tsujita, Masaharu Terauchi, Toshikazu Wakabayashi, Hiroshi Asano, Shinichiro Hashimoto, Keiji Akamatsu
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Publication number: 20100149220Abstract: The total number of the scan electrodes is divided into a first scan electrode group and a second scan electrode group. The first scan electrode group drive section for driving the first scan electrode group produces a selection potential and a non-selection potential in the scan period, and supplies scan pulses based on the two potentials in the first half of the scan period. The complex switch section supplies the selection potential produced using the first scan electrode group drive section to the second scan electrode group drive section for driving the second scan electrode group in the latter half of the scan period. The second scan electrode group drive section supplies scan pulses based on the input selection potential.Type: ApplicationFiled: December 20, 2007Publication date: June 17, 2010Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTDInventors: Yasuhiro Arai, Keiji Akamatsu, Toshikazu Wakabayashi, Mitsuhiro Murata
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Publication number: 20100039415Abstract: A plasma display panel; a scan electrode drive circuit for generating a gently decreasing downward inclined waveform voltage in an initializing period, a gently increasing first inclined waveform voltage in an initializing period of at least one subfield in one field period, and a second inclined waveform voltage having a steeper gradient than the first inclined waveform voltage and decreasing immediately after the increasing waveform voltage reaches a predetermined potential in the last part of the sustain period; and a panel temperature detecting circuit are provided. The lowest voltage in the downward inclined waveform voltage is switched at a first voltage, a second voltage higher than the first voltage and a third voltage higher than the second voltage to generate a downward inclined waveform voltage. The lowest voltage is switched according to the temperature detected by the panel temperature detecting circuit to generate the downward inclined waveform voltage.Type: ApplicationFiled: April 23, 2008Publication date: February 18, 2010Applicant: Panasonic CorporationInventors: Hiroshi Ibaraki, Minoru Takeda, Keiji Akamatsu, Kenji Ogawa, Nobuhiko Nakamura
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Publication number: 20100033454Abstract: In the method for driving a plasma display panel and the plasma display device, the scan electrodes of the plasma display panel are divided into two scan electrode groups, the address period of subfields is divided into two address periods corresponding to the two scan electrode groups, and at least in one address period, the scan electrodes belonging to the scan electrode group provided with scan pulses are sequentially provided with scan pulses shifting from second voltage higher than scan pulse voltage to scan pulse voltage and shifting again to second voltage, and the scan electrodes belonging to the scan electrode group not provided with scan pulses are provided with either third voltage higher than scan pulse voltage or fourth voltage higher than second voltage and third voltage, and with third voltage at least while scan pulse voltage is applied to adjacent scan electrodes.Type: ApplicationFiled: March 27, 2008Publication date: February 11, 2010Inventors: Kenji Ogawa, Keiji Akamatsu, Yasuhiro Arai
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Publication number: 20100013819Abstract: In a former half (T11) of an all-cell reset period (T1), the potential of a scan electrode (Scn) is raised from 0 [V] to Vp [V] at a timing t0, and thereafter maintained at the positive potential of Vp [V] to Vg [V] until a timing t3 when the former half (T11) ends. On the other hand, in the same former half (T11), a reset pulse (Pul.2), which includes a negative ramp waveform portion from 0 [V] to a potential of Vr [V], is applied to a sustain electrode (Sus). A time period (t1?t0) of the negative ramp waveform portion of the pulse (Pul.2) is set longer than a time period required for the potential change of a pulse (Pul.1) from P1 to P2.Type: ApplicationFiled: June 8, 2006Publication date: January 21, 2010Inventors: Keiji Akamatsu, Kenji Ogawa, Mitsuo Ueda
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Publication number: 20090244053Abstract: An object of the present invention is to provide a method for driving a plasma display panel capable of further reducing an address error to realize satisfactory image quality, and a plasma display apparatus.Type: ApplicationFiled: June 6, 2007Publication date: October 1, 2009Inventors: Keiji Akamatsu, Toshikazu Wakabayashi, Yasuhiro Arai, Mitsuhiro Murata
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Publication number: 20090179877Abstract: In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an initializing period for causing initializing discharge in a discharge cell, an address period for selectively causing address discharge in the discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. A holding period when discharge is not caused is disposed before the head subfield belonging to at least one subfield group of the plurality of subfield groups. In the initializing period of the head subfield belonging to at least one subfield group, an initializing operation of causing initializing discharge is performed in the discharge cell where the sustain discharge has been performed in the sustain period of the immediately preceding subfield.Type: ApplicationFiled: April 10, 2008Publication date: July 16, 2009Applicant: Panasonic CorporationInventors: Keiji Akamatsu, Minoru Takeda, Kenji Ogawa, Hiroshi Ibaraki
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Publication number: 20090102755Abstract: In a driving method of a panel, one field period is formed by arranging a plurality of subfields that have an address period for selectively causing address discharge in a discharge cell, and a sustain period for causing as many sustain discharges as the number corresponding to luminance weight in the discharge cell. One field period is formed by arranging a plurality of subfield groups having a plurality of subfields whose luminance weights monotonically increase. In the discharge cell for causing address discharge in a certain subfield other than the head subfield in each subfield group, address discharge is caused even in the head subfield.Type: ApplicationFiled: April 10, 2008Publication date: April 23, 2009Applicant: Panasonic CorporationInventors: Minoru Takeda, Kenji Ogawa, Keiji Akamatsu
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Publication number: 20090015520Abstract: The present invention provides a plasma display panel and a method for driving the plasma display panel each of which ensures to suppress problems associated with an erroneous discharge resulting from accidental occurrence of a strong discharge in a reset period as well as with an address discharge delay. The problems are suppressed without applying an auxiliary erase pulse after the reset period ends. As a result, image display is provided with no flickering and good quality. The reset period includes a first step of applying a voltage having an ascending ramp waveform and a second step of applying a voltage having a descending ramp waveform. Between the first and second steps, a potential change waveform having a rise or fall (voltage change pulse) is applied at least to scan electrodes, sustain electrodes, or address electrodes.Type: ApplicationFiled: March 23, 2006Publication date: January 15, 2009Inventors: Keiji Akamatsu, Kenji Ogawa, Mitsuo Ueda