Patents by Inventor Shunji Ohta

Shunji Ohta 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: 7903050
    Abstract: In a conventional image display apparatus, since display load ratios for respective lines are different, voltage drop amounts are also different and a difference in brightness occurs in spite of giving the same inputted luminance signal, so that image quality of display image is degraded. In the case where signals at the same luminance level are inputted and displayed, for a pixel on a display panel, an ON pattern of a subfield in one field is changed when a line load ratio of a line including the pixel is changed. That is, an image display apparatus using a display panel having a plurality of pixels is configured so as to include, for each of the plurality of pixels connected to one driving electrode, a load calculating means that calculates the load ratio and a luminance correcting means that calculates a drop amount in luminance level of an inputted video signal for correction.
    Type: Grant
    Filed: December 2, 2005
    Date of Patent: March 8, 2011
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Yuichiro Kimura, Shunji Ohta, Yoshinori Miyazaki
  • Publication number: 20080278416
    Abstract: In a PDP apparatus (multiple grayscale display apparatus), an technique for reducing the unevenness of the electric charge states between cells and the background emission by the reset discharge, and also reducing the false outline, therefore, the image quality can be improved, and the drive can be stabilized is provided. In a multiple grayscale display method by sub field method, a structure in which as a sub field lighting pattern, in only specified sub fields (example: SF3, SF9), light-off sub fields in halfway of continuous light-on sub fields are permitted, is employed. Thereby, the unevenness of the electric charge states between cells is reduced and omission of reset discharge becomes easy, since the number of light-off in halfway is small, the false outlines is reduced.
    Type: Application
    Filed: June 15, 2007
    Publication date: November 13, 2008
    Inventors: Shunji Ohta, Shinsuke Tanaka, Yuichiro Kimura
  • Patent number: 7420576
    Abstract: A display apparatus displaying gray scale by using a subfield method has a gain control circuit, a sub gain control circuit, and an error diffusion circuit. The gain control circuit has the number of gray scale levels of an input signal and outputting a first intermediate image signal with a first number of gray scale levels, and the sub gain control circuit receives the first intermediate image signal, compresses the number of gray scale levels of the first intermediate image signal, and outputs a second intermediate image signal with a second number of gray scale levels. The error diffusion circuit receives the second intermediate image signal and increase the number of gray scale levels by simulating additional gray scale levels through error diffusion.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: September 2, 2008
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Masanori Takeuchi, Masaya Tajima, Yutaka Chiaki, Shunji Ohta, Akira Yamamoto
  • Publication number: 20080012883
    Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.
    Type: Application
    Filed: July 17, 2007
    Publication date: January 17, 2008
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Shunji OHTA, Masanori Takeuchi, Yutaka Chiaki, Masaya Tajima, Akira Yamamoto
  • Publication number: 20070222712
    Abstract: An image display apparatus divides one field into plural weighted subfields and combines the plural subfields to perform a multi-gray-scale image display on a display panel. The image display apparatus includes a motion amount detecting circuit 50, a diffusion amount calculating circuit 52, and a diffusion circuit 53. The motion amount detecting circuit 50 detects a motion amount from a current field and a field before the current field based on an input image signal. The diffusion amount calculating circuit 52 calculates a diffusion amount to diffuse false contour noise to the surrounding, based on a gray scale of the input image signal and the detected motion amount. The diffusion circuit 53 performs a diffuse process in the calculated diffusion amount. With this arrangement, it is possible to improve the image quality of a moving-image display, by decreasing a false contour, without generating additional noise and without increasing the circuit scale.
    Type: Application
    Filed: August 23, 2005
    Publication date: September 27, 2007
    Inventors: Yutaka Chiaki, Shunji Ohta, Yuichiro Kimura
  • Patent number: 7256755
    Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: August 14, 2007
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Shunji Ohta, Masanori Takeuchi, Yutaka Chiaki, Masaya Tajima, Akira Yamamoto
  • Patent number: 7209152
    Abstract: A signal processor for multiple gradations for carrying out coding by replacing an input image signal with a plurality of subfields, comprising a main path for generating a primary color signal having a first number of gradations, a sub-path for generating a primary color signal having a second number of gradations, which is smaller than the first number of gradations, a switch, a movement detection circuit, a level detection circuit, a path switching control circuit for switching the switch based on the amount of movement and the level, plural subfield coding circuits for carrying out subfield coding different from each another, a superposing circuit for selecting one of the outputs of the plural subfield coding circuits, and a superposing control circuit, and thus preventing a moving false contour.
    Type: Grant
    Filed: March 16, 2004
    Date of Patent: April 24, 2007
    Assignee: Fujitsu Hitachi Plasma Display Limited
    Inventors: Yutaka Chiaki, Shunji Ohta, Masanori Takeuchi, Masaya Tajima, Akira Yamamoto, Yuichiro Kimura
  • Publication number: 20060132659
    Abstract: In a conventional image display apparatus, since display load ratios for respective lines are different, voltage drop amounts are also different and a difference in brightness occurs in spite of giving the same inputted luminance signal, so that image quality of display image is degraded. In the case where signals at the same luminance level are inputted and displayed, for a pixel on a display panel, an ON pattern of a subfield in one field is changed when a line load ratio of a line including the pixel is changed. That is, an image display apparatus using a display panel having a plurality of pixels is configured so as to include, for each of the plurality of pixels connected to one driving electrode, a load calculating means that calculates the load ratio and a luminance correcting means that calculates a drop amount in luminance level of an inputted video signal for correction.
    Type: Application
    Filed: December 2, 2005
    Publication date: June 22, 2006
    Inventors: Yuichiro Kimura, Shunji Ohta, Yoshinori Miyazaki
  • Publication number: 20040263538
    Abstract: A display apparatus displaying gray scale by using a subfield method has a main path, a sub path, a switch circuit, a motion region detection circuit, a first judging circuit, a level detection circuit, a motion detection correction circuit, and a second judging circuit. The switch circuit outputs a first image signal generated by the main path or a second image signal generated by the sub path by switching therebetween, and the first judging circuit outputs a first motion signal in accordance with an output of the motion region detection circuit. The motion detection correction circuit receives the first motion signal and a level signal, and outputs a second motion signal in accordance with the level signal, and the second judging circuit receives the second motion signal and the level signal, and outputs a switching control signal to the switch circuit.
    Type: Application
    Filed: March 16, 2004
    Publication date: December 30, 2004
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Shunji Ohta, Masanori Takeuchi, Yutaka Chiaki, Masaya Tajima, Akira Yamamoto
  • Publication number: 20040263539
    Abstract: A signal processor for multiple gradations for carrying out coding by replacing an input image signal with a plurality of subfields, comprising a main path for generating a primary color signal having a first number of gradations, a sub-path for generating a primary color signal having a second number of gradations, which is smaller than the first number of gradations, a switch, a movement detection circuit for detecting the amount of movement from the change in primary color signal between the current field and the preceding field, a level detection circuit for detecting the level indicating the tendency for a moving image false contour to occur, a path switching control circuit for switching the switch based on the amount of movement and the level, plural subfield coding circuits for carrying out subfield coding different from each another, a superposing circuit for selecting one of the outputs of the plural subfield coding circuits, and a superposing control circuit, and thus preventing a moving false cont
    Type: Application
    Filed: March 16, 2004
    Publication date: December 30, 2004
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Yutaka Chiaki, Shunji Ohta, Masanori Takeuchi, Masaya Tajima, Akira Yamamoto, Yuichiro Kimura
  • Publication number: 20040263541
    Abstract: A display apparatus displaying gray scale by using a subfield method has a gain control circuit, a sub gain control circuit, and an error diffusion circuit. The gain control circuit has the number of gray scale levels of an input signal and outputting a first intermediate image signal with a first number of gray scale levels, and the sub gain control circuit receives the first intermediate image signal, compresses the number of gray scale levels of the first intermediate image signal, and outputs a second intermediate image signal with a second number of gray scale levels. The error diffusion circuit receives the second intermediate image signal and increase the number of gray scale levels by simulating additional gray scale levels through error diffusion.
    Type: Application
    Filed: March 24, 2004
    Publication date: December 30, 2004
    Applicant: FUJITSU HITACHI PLASMA DISPLAY LIMITED
    Inventors: Masanori Takeuchi, Masaya Tajima, Yutaka Chiaki, Shunji Ohta, Akira Yamamoto