Patents by Inventor Takao Wakitani

Takao Wakitani 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: 7525512
    Abstract: An improved method of testing and inspecting a plasma display panel. In a plasma display panel, a plurality of cells are formed at an intersection of each electrode disposed in a row direction and in a column direction of the panel. A field is formed of a plurality of sub-fields, and the combination of the sub-fields enables the panel to have a gradation display. In the inspection method, an address pulse voltage is not applied to a target cell to be inspected in a predetermined sub-field, but is applied to at least one cell of the cells adjacent to the target cell, and the address pulse voltage is applied to the target cell in the successive sub-field. If the barrier ribs of the target cell have an imperfection, wall charges of the cell are affected by the discharge occurred in an adjacent cell, and the target cell fails to light on in the successive sub-field. The inspection method can thus detect lighting failure caused by defective barrier ribs.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: April 28, 2009
    Assignee: Panasonic Corporation
    Inventors: Tsuneo Ikura, Takao Wakitani
  • Patent number: 7355434
    Abstract: A light inspection device for performing lighting inspection of a display panel contains a circuit board having a driving circuit for a lighting display panel; a conductive chassis that functions as the ground potential of the driving circuit; and a conductive support member fixed to the chassis for fixing the circuit board. The chassis and the support member are joined via soft metal.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: April 8, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tsuneo Ikura, Takao Wakitani, Toshiya Otani
  • Publication number: 20060132049
    Abstract: Disclosed is an improved method of performing lighting inspection on a plasma display panel. In a plasma display panel, a plurality of cells is formed at an intersection of each electrode disposed in a row direction and in a column direction of the panel. A field is formed of a plurality of sub-fields, and the combination of the sub-fields enables the panel to have gradation display. In the inspection method, address pulse voltage is not applied to a target cell to be inspected in a predetermined sub-field, but applied to at least one cell of the cells adjacent to the target cell, and the address pulse voltage is applied to the target cell in the successive sub-field. If the barrier ribs of the target cell have an imperfection, wall charges of the cell are affected by the discharge occurred in an adjacent cell, and the target cell fails to light on in the successive sub-field. The inspection method can thus detect lighting failure caused by defective barrier ribs.
    Type: Application
    Filed: November 22, 2004
    Publication date: June 22, 2006
    Inventors: Tsuneo Ikura, Takao Wakitani
  • Publication number: 20060022684
    Abstract: Disclosed here is a light inspection device for performing lighting inspection of a display panel. With the use of the device, a display panel can be tested under the display condition equivalent to that of a finished panel as a product, which improves accuracy of inspection. The light inspection device contains circuit board (27) having a driving circuit for lighting display panel (21); conductive chassis (25) that functions as the ground potential of the driving circuit; and conductive support member (26) fixed to chassis (25) for fixing circuit board (27). Chassis (25) and support member (26) are joined via soft metal (28).
    Type: Application
    Filed: September 28, 2004
    Publication date: February 2, 2006
    Inventors: Tsumeo Ikura, Takao Wakitani, Toshiya Otani
  • Patent number: 6542135
    Abstract: The display device of the present invention is provided with a means (8) for setting the writing pulse width of the attentional light-emitting sub-field wider than the normal writing pulse width at all the gray scale levels in the case where at least two continuous non-light-emitting sub-fields possibly exist before the attentional light-emitting sub-field at a certain gray scale level among all the gray scale levels specified on the basis of the number Z of sub-fields and the weighting of the sub-fields. According to the display device of the present invention, the discharge for writing can be stably executed without reducing the number of sub-fields in one field.
    Type: Grant
    Filed: July 18, 2000
    Date of Patent: April 1, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Mitsuhiro Kasahara, Yuichi Ishikawa, Tomoko Morita, Makoto Kawachi, Tadayuki Masumori, Takao Wakitani, Toshio Wakahara, Akira Yawata
  • Patent number: 6294875
    Abstract: A method of driving an AC plasma display panel for carrying out gray-scale display using a structure in which each field consists of a plurality of subfields, each of which includes an initialization period, a write period, and a sustain period. At least in one predetermined subfield out of the plurality of subfields, at least a part of a sustain operation in the sustain period and at least a part of an initialization operation in the initialization period in a subsequent subfield are carried out at the same time. The visibility of black is improved considerably and the contrast can be enhanced greatly.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: September 25, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takatsugu Kurata, Shinji Masuda, Makoto Kawachi, Yukiharu Ito, Takao Wakitani
  • Patent number: 6236380
    Abstract: A method for displaying an image with gradation and a high brightness with a plasma display panel is provided. In this method, one field is divided into eight subfields, and each subfield is divided into an addressing period and sustaining period. In the upper four bits b4, b5, b6, and b7, in which the sustaining period is long, all of the scanning electrodes are scanned sequentially. In the lower four bits b0, b1, b2 and b3, in which the sustaining period is short, the scanning electrodes are scanned alternately by interlace scanning.
    Type: Grant
    Filed: July 6, 1998
    Date of Patent: May 22, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Koichi Wani, Naoki Kosugi, Takao Wakitani
  • Patent number: 6198463
    Abstract: In a method of driving an AC-type plasma display panel in which a first insulation substrate and a second insulation substrate are disposed so as to be opposed to each other, pairs of scanning electrodes and sustaining electrodes covered with a dielectric layer and a protective layer are arranged on the first insulation substrate and at least data electrodes are arranged on the second insulation substrate so as to be orthogonal to the pairs of scanning and sustaining electrodes, immediately after termination of application of a sustaining pulse voltage to one of the scanning electrodes and the sustaining electrodes, the sustaining pulse voltage is applied to the other.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: March 6, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukiharu Ito, Takao Wakitani
  • Patent number: 6150766
    Abstract: A plurality of scanning electrodes and a plurality of sustaining electrodes parallel to each other are located on an inner face of a first glass substrate. Each of the scanning electrodes and each of the sustaining electrodes form a pair. A dielectric layer and a protection layer are formed on the first glass substrate in this order, covering the electrodes. A plurality of data electrodes perpendicular to the scanning electrodes and the sustaining electrodes are located on an inner face of a second glass substrate which is located opposed to the first glass substrate with a discharge space interposed therebetween. In an AC-type PDP having such a structure, at least one of the plurality of scanning electrodes and the plurality of sustaining electrodes are divided into a plurality of groups, and pulses having different phases are applied to the electrodes in different groups, thereby causing sustaining discharge. The scanning electrodes and the sustaining electrodes may be comb-like with teeth.
    Type: Grant
    Filed: November 7, 1996
    Date of Patent: November 21, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taichi Shino, Takio Okamoto, Kazunori Hirao, Koichi Itsuda, Yukiharu Ito, Takao Wakitani, Toru Hirayama
  • Patent number: 6118220
    Abstract: A plurality of scanning electrodes and a plurality of sustaining electrodes parallel to each other are located on an inner face of a first glass substrate. Each of the scanning electrodes and each of the sustaining electrodes form a pair. A dielectric layer and a protection layer are formed on the first glass substrate in this order, covering the electrodes. A plurality of data electrodes perpendicular to the scanning electrodes and the sustaining electrodes are located on an inner face of a second glass substrate which is located opposed to the first glass substrate with a discharge space interposed therebetween. In an AC-type PDP having such a structure, at least one of the plurality of scanning electrodes and the plurality of sustaining electrodes are divided into a plurality of groups, and pulses having different phases are applied to the electrodes in different groups, thereby causing sustaining discharge. The scanning electrodes and the sustaining electrodes may be comb-like with teeth.
    Type: Grant
    Filed: July 14, 1999
    Date of Patent: September 12, 2000
    Assignee: Matsushita Electronics Corporation
    Inventors: Taichi Shino, Takio Okamoto, Kazunori Hirao, Koichi Itsuda, Yukiharu Ito, Takao Wakitani, Toru Hirayama
  • Patent number: 6072279
    Abstract: A plurality of scanning electrodes and a plurality of sustaining electrodes parallel to each other are located on an inner face of a first glass substrate. Each of the scanning electrodes and each of the sustaining electrodes form a pair. A dielectric layer and a protection layer are formed on the first glass substrate in this order, covering the electrodes. A plurality of data electrodes perpendicular to the scanning electrodes and the sustaining electrodes are located on an inner face of a second glass substrate which is located opposed to the first glass substrate with a discharge space interposed therebetween. In an AC-type PDP having such a structure, at least one of the plurality of scanning electrodes and the plurality of sustaining electrodes are divided into a plurality of groups, and pulses having different phases are applied to the electrodes in different groups, thereby causing sustaining discharge. The scanning electrodes and the sustaining electrodes may be comb-like with teeth.
    Type: Grant
    Filed: March 29, 1999
    Date of Patent: June 6, 2000
    Assignee: Matsushita Electronics Corporation
    Inventors: Taichi Shino, Takio Okamoto, Kazunori Hirao, Koichi Itsuda, Yukiharu Ito, Takao Wakitani, Toru Hirayama
  • Patent number: 6034656
    Abstract: The plasma display panel having brightness display ranges comprising a gradation brightness display range which displays gradation brightness corresponding to the input signals under a preset input signal level and a constant brightness display range which displays a constant peak brightness greater than the maximum brightness corresponding to input signals greater than the preset input signal level. The plasma display panel can provide the gradation display up to the maximum brightness corresponding to the input signals up to the maximum input and provide the constant peak brightness corresponding to the peak level input by adding one additional weighting bit for the higher gradation. Consequently, a high quality brightness display with high mean value of the brightness and sufficiently high peak brightness can be achieved. Furthermore, the plasma display panel enhances the brightness weighting value and the value of .gamma. for the reverse .gamma.
    Type: Grant
    Filed: September 15, 1997
    Date of Patent: March 7, 2000
    Assignees: Matsushita Electric Industrial Co., Ltd., Matsushita Electronics Corporation
    Inventors: Kumetsugu Yamamoto, Yukiharu Ito, Akio Niwa, Takao Wakitani, Takuma Higashi
  • Patent number: 5969478
    Abstract: A plurality of scanning electrodes and a plurality of sustaining electrodes parallel to each other are located on an inner face of a first glass substrate. Each of the scanning electrodes and each of the sustaining electrodes form a pair. A dielectric layer and a protection layer are formed on the first glass substrate in this order, covering the electrodes. A plurality of data electrodes perpendicular to the scanning electrodes and the sustaining electrodes are located on an inner face of a second glass substrate which is located opposed to the first glass substrate with a discharge space interposed therebetween. In an AC-type PDP having such a structure, at least one of the plurality of scanning electrodes and the plurality of sustaining electrodes are divided into a plurality of groups, and pulses having different phases are applied to the electrodes in different groups, thereby causing sustaining discharge. The scanning electrodes and the sustaining electrodes may be comb-like with teeth.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: October 19, 1999
    Assignee: Matsushita Electronics Corporation
    Inventors: Taichi Shino, Takio Okamoto, Kazunori Hirao, Koichi Itsuda, Yukiharu Ito, Takao Wakitani, Toru Hirayama
  • Patent number: 5940142
    Abstract: A display device driving for a gray scale expression, wherein at least a sub-field having the highest luminance value among plural sub-fields is further divided into a plurality of sub-field parts.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: August 17, 1999
    Assignee: Matsushita Electronics Corporation
    Inventors: Takao Wakitani, Kouichi Itsuda
  • Patent number: 5656893
    Abstract: A plurality of scanning electrodes and a plurality of sustaining electrodes parallel to each other are located on an inner face of a first glass substrate. Each of the scanning electrodes and each of the sustaining electrodes form a pair. A dielectric layer and a protection layer are formed on the first glass substrate in this order, covering the electrodes. A plurality of data electrodes perpendicular to the scanning electrodes and the sustaining electrodes are located on an inner face of a second glass substrate which is located opposed to the first glass substrate with a discharge space interposed therebetween. In an AC-type PDP having such a structure, at least one of the plurality of scanning electrodes and the plurality of sustaining electrodes are divided into a plurality of groups, and pulses having different phases are applied to the electrodes in different groups, thereby causing sustaining discharge. The scanning electrodes and the sustaining electrodes may be comb-like with teeth.
    Type: Grant
    Filed: April 25, 1995
    Date of Patent: August 12, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taichi Shino, Takio Okamoto, Kazunori Hirao, Koichi Itsuda, Yukiharu Ito, Takao Wakitani, Toru Hirayama
  • Patent number: 5629716
    Abstract: A plurality of filaments are stretched in parallel on a rear plate, and an insulating plate is provided so as to cover the filaments. In the insulating plate, a plurality of through-holes are formed along the longitudinal direction of the respective filaments for exposing parts thereof. Each through-hole and phosphor layers, which are provided on the insulating layer adjacent to the through-hole, constitute one unit picture element. The respective phosphor layers in the respective picture element are installed in a plurality of cavities formed in a rib provided on a lower surface of the insulating plate, whereby separated from the neighboring phosphor layers. The respective cavities function as a discharge room, with a light-transmissive front plate, formed on the rib, as a lid and a portion of the insulating plate corresponding to the phosphor layer as a bottom. The respective discharge rooms overlap the through-hole at one end in the longitudinal direction thereof.
    Type: Grant
    Filed: July 14, 1994
    Date of Patent: May 13, 1997
    Assignee: Matsushita Electronics Corporation
    Inventors: Takio Okamoto, Kazunori Hirao, Toru Hirayama, Hajime Mae, Takao Wakitani, Yukiharu Ito, Kouichi Nomura, Seiji Matsubara