Patents by Inventor Kengo Takahama

Kengo Takahama 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: 6239788
    Abstract: In a coordinate detection period, a first electrode drive circuit sequentially selects source electrodes Sn of the TFT LCD panel to connect the same to an x-signal current amplifying circuit, and to apply an AC voltage to the non-selected electrodes. The x-signal current amplifying circuit detects a detection current flowing through the selected electrode, the magnitude of which corresponds to a distance to a finger (or a conductor pen), to obtain an x-coordinate detection voltage. A second electrode drive circuit and a y-signal current amplifying circuit operate in similar fashion to obtain a y-coordinate detection voltage. A coordinate detection circuit then obtains the x- and y-coordinate values of the designated position based on the x-coordinate detection voltage and the y-coordinate detection voltage, thus enabling pointing by a codeless pen and a finger.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: May 29, 2001
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Hitoshi Nohno, Masayuki Katagiri, Kiyohiro Nozaki, Kengo Takahama, Hiroyuki Iwahashi
  • Patent number: 5905489
    Abstract: An M-sequence signal is generated in an M-sequence generation circuit, and the M-sequence signal, which is successively delayed by a column-electrode driving circuit or a row-electrode driving circuit, is applied to a column-electrode group or a row-electrode group. A correlator finds a correlation between the M-sequence signal and a detection signal that has been detected by amplifying electrostatically induced voltage that appeared in the detection electrode of an electronic pen so that a position specified by the electronic pen is detected by a detection circuit as a coordinate signal. Thus, it is possible to obtain a coordinate detection signal having a superior S/N ratio without reducing the coordinate detection speed, and consequently to carry out a coordinate detecting operation with high precision.
    Type: Grant
    Filed: February 12, 1997
    Date of Patent: May 18, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kengo Takahama, Hitoshi Nohno
  • Patent number: 5854881
    Abstract: Provided is a coordinate detection device capable of preventing the increase of development cost and the reduction of yield and dispensing with additional investment for the existing equipment. There are provided an LCD panel having electrodes and electrodes, a magnetic field generator which outputs an AC magnetic field from a tip end of its electrode, a differential amplifier, switching circuits which sequentially select electrodes of the LCD panel and connect the electrodes to the differential amplifier, and a coordinate detection circuit which detects the coordinates of a position in which the magnetic field generator is located based on a timing at which the electrodes are selected and an output of the differential amplifier. A coordinate detection function can be achieved by means of the LCD panel having the same structure as that of the LCD panel provided specially for image display.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: December 29, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Yoshida, Kengo Takahama, Takao Tagawa
  • Patent number: 5825345
    Abstract: During a display period (Y-coordinate detection period), an image is written to an electro-optical material so as to form a display by driving row electrodes and column electrodes by using a row-electrode driving circuit and a column-electrode driving circuit so as to selectively operate TFTs. In this case, a shift data signal having a width corresponding to two clocks of a horizontal sync signal is supplied to the row-electrode driving circuit by using a start-pulse-width expanding circuit; therefore, two row-electrode scanning signals are simultaneously inputted to two of the corresponding row electrodes. Moreover, the row-electrode scanning signals have periods in which they instantaneously turn "off" respectively, and the turning-off timing is coincident in the respective signals.
    Type: Grant
    Filed: August 1, 1996
    Date of Patent: October 20, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kengo Takahama, Takao Tagawa, Kiyohiro Nozaki
  • Patent number: 5798756
    Abstract: There is provided a coordinate detection device capable of preventing increase of development cost and reduction of yield and dispensing with additional investment for existing equipment. The coordinate detection device includes an LCD panel having electrodes and electrodes, an electric field generator which outputs an AC electric field from a tip end of its electrode, a differential amplifier, switching circuits which sequentially select electrodes of the LCD panel and connect the selected electrodes to the differential amplifier, and a coordinate detection circuit which detects coordinates of a position in which the electric field generator is located based on a timing at which the electrodes are selected and an output of the differential amplifier. A coordinate detection function can be achieved by means of the LCD panel having the same structure as that of an LCD panel provided specially for image display.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: August 25, 1998
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Yoshida, Kengo Takahama, Takao Tagawa
  • Patent number: 5675357
    Abstract: A backlight emits diffused light beams. An emission direction characteristic-forming plate allows light beams which have been incident thereon at generally right angles therewith to pass therethrough and intercepts light beams which have been incident thereon obliquely. An image display/input panel has light receiving elements each incorporated in a corresponding pixel having a liquid crystal cell. In an image input operation, pixels are sequentially turned on and off so as to scan an original document by parallel light emitted vertically from a turned-on pixel. Light reflected by the original document is received by the light receiving element incorporated in the turned-on pixel and converted into an electric signal. Light emitted from the turned-on pixel of the image display/input panel and reflected by the original document is received by only the turned-on pixel. In this manner, a high resolution can be obtained in the image input operation.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: October 7, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasuhiro Yoshida, Kengo Takahama, Yoshihiko Takeda, Yoshihiro Yamamoto
  • Patent number: 5631666
    Abstract: A detection and hold circuit outputs a reference signal having a level proportional to an x-coordinate detection pulse input from an X-coordinate signal amplifier. A delay element delays the reference signal. An adder adds the x-coordinate detection pulse from the X-coordinate signal amplifier and a delayed signal from the delay element. Comparators obtain a coordinate detection pulse making a detection signal from another detection and hold circuit for an LCD voltage inversion pulse serve as a reference signal. Thus noise following the x-coordinate detection pulse is removed to generate a coordinate detection pulse with a reference value corresponding to the level of the LCD voltage inversion pulse to allow a stable coordinate detection to be achieved.
    Type: Grant
    Filed: January 13, 1995
    Date of Patent: May 20, 1997
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takao Tagawa, Kengo Takahama, Kazunari Okamura, Noritoshi Kako
  • Patent number: 5469274
    Abstract: An image processing apparatus comprises an image storing device and an image inputting device, in which a parameter determining circuit compares an image input through the image inputting device with an image stored in the image storing device to calculate parameters for correction and in which the input image is corrected by a correction method different from that effected on the image having been stored, then to be combined therewith. The processing is sequentially effected on time-serially input images to produce a higher resolution image in the image storing device as compared with the input images.
    Type: Grant
    Filed: March 3, 1993
    Date of Patent: November 21, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Keisuke Iwasaki, Kengo Takahama
  • Patent number: 5430479
    Abstract: A moving vector extractor for detecting a shaking of an image through a video camera in order to improve accuracy of the detection. Even when the image is dark or of low density gradient as a whole, a density gradient value around representative point is calculated. Basic data of moving vector of the difference value between successive frames is obtained by calculating an absolute value or a squared value. The basic data of the moving vector is weighted according to a density gradient value so as to improve the precision of moving vector extraction.
    Type: Grant
    Filed: October 16, 1991
    Date of Patent: July 4, 1995
    Assignees: Sharp Corporation, Ezel Inc.
    Inventors: Kengo Takahama, Yasukuni Yamane
  • Patent number: 5410329
    Abstract: A detection and hold circuit outputs a reference signal having a level proportional to an x-coordinate detection pulse input from an X-coordinate signal amplifier. A delay element delays the reference signal. An adder adds the x-coordinate detection pulse from the X-coordinate signal amplifier and a delayed signal from the delay element. Comparators obtain a coordinate detection pulse making a detection signal from another detection and hold circuit for an LCD voltage inversion pulse serve as a reference signal. Thus noise following the x-coordinate detection pulse is removed to generate a coordinate detection pulse with a reference value corresponding to the level of the LCD voltage inversion pulse to allow a stable coordinate detection to be achieved.
    Type: Grant
    Filed: May 21, 1993
    Date of Patent: April 25, 1995
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takao Tagawa, Kengo Takahama, Kazunari Okamura, Noritoshi Kako
  • Patent number: 5309244
    Abstract: An image processing apparatus is provided to have a spatial light modulator onto and from which an image data is written and read, a digital reading system for digitally reading an image data written on the spatial light modulator, a processing unit for processing the read image data, and a digital writing system for digitally writing the processed data on the spatial light modulator. The digital reading or writing system serves to two-dimensionally move a laser beam on the spatial light modulator for reading or writing an image data from or onto the spatial light modulator. The digital reading or writing system provides a hologram disk having hologram lenses located in a concentric or spiral manner. The hologram disk is arranged to deflect the laser beam vertically and horizontally for scanning the spatial modulating element.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: May 3, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Masayuki Katagiri, Kengo Takahama, Noritoshi Kako
  • Patent number: 5253061
    Abstract: A television image processing apparatus has a memory for storing television signals with respect to a predetermined frame image. The apparatus also has an arithmetic correlation circuit for calculating correlation quantity between television signals of each frame image applied thereto in real time and television signals of the frame image stored in the memory, and a control circuit for generating a control signal when the correlation quantity calculated by the arithmetic correlation circuit exceeds a predetermined value.
    Type: Grant
    Filed: May 9, 1991
    Date of Patent: October 12, 1993
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kengo Takahama, Yasukuni Yamane