Patents by Inventor Toshiyuki Kasai

Toshiyuki Kasai 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).

  • Publication number: 20090190199
    Abstract: An electro-optical device includes a controller, a reference current source, a correction current source, a combining unit, and an electro-optical element. The controller generates a reference current control signal defining a first period during which a reference current is output, and a correction current control signal defining a second period during which a correction current is output, the second period being shorter than the first period. The reference current source generates the reference current based on the reference current control signal. The correction current source generates the correction current based on the correction current control signal. The combining unit combines the reference current and the correction current to generate a driving current. The electro-optical element emits an amount of light corresponding to the driving current.
    Type: Application
    Filed: April 3, 2009
    Publication date: July 30, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Toshiyuki KASAI
  • Patent number: 7567229
    Abstract: The invention provides an electro-optical device that stabilizes display quality by performing correction processing corresponding to a plurality of disturbance factors. Specifically, a grayscale characteristic generating unit can generate conversion data having grayscale characteristics obtained by changing the grayscale characteristics of display data that defines the grayscales of pixels with reference to a conversion table whose description contents include correction factors. A data line driving circuit can drive the pixels after correcting the grayscale characteristics of the conversion data by the correction factors using other processing different from the that performed by the grayscale characteristic generating unit.
    Type: Grant
    Filed: May 21, 2004
    Date of Patent: July 28, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Toshiyuki Kasai, Yoichi Imamura
  • Publication number: 20090184986
    Abstract: The invention provides an electro-optical apparatus that can prevent a shift in a threshold voltage of an amorphous silicon transistor while driving an organic EL device in a pixel circuit including the amorphous silicon transistor. A characteristic-adjustment circuit can be provided, which has a function of returning a shift in the threshold voltage of the amorphous silicon transistor included in the pixel circuit to the original state.
    Type: Application
    Filed: July 23, 2008
    Publication date: July 23, 2009
    Applicant: Seiko Epson Corporation
    Inventors: Toshiyuki Kasai, Yoichi Imamura, Tokuro Ozawa
  • Patent number: 7551151
    Abstract: The invention provides an electronic circuit that can include a programming path and a reproduction path. The circuit can further include a current driven element, a transistor in the production path arranged so as to operatively control a current supplied to the current driven element, a capacitor arranged for storing an operating voltage of the transistor, an additional transistor arranged in parallel to the transistor in the programming path for storing the capacitor and the operating voltage, and a switching device that controls the programming path and the reproduction path.
    Type: Grant
    Filed: November 4, 2005
    Date of Patent: June 23, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Toshiyuki Kasai, Simon Tam
  • Publication number: 20090140265
    Abstract: A light emitting device includes a substrate having transparency, a light emitting element that emits light at least to the substrate side, and a light detecting element that is formed between the light emitting element and the substrate. The light detecting element is formed along an outer frame of the light emitting element in a plan view.
    Type: Application
    Filed: November 12, 2008
    Publication date: June 4, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Tsukasa EGUCHI, Hiroaki JO, Eiji KANDA, Toshiyuki KASAI, Atsushi ITO
  • Publication number: 20090140658
    Abstract: There is provided a method of driving a light emitting device including a light emitting element and a unit circuit that is disposed in correspondence with the light emitting element and drives the tight emitting element in accordance with emission control data generated based on image data, wherein the light emitting device has a temperature sensor and a light receiving sensor. The method includes detecting the temperature of the light emitting device by using the temperature sensor, detecting light emitted from the light emitting element by using the light receiving sensor, and generating the emission control data by correcting the image data in response to the temperature of the light emitting device which is detected by the temperature sensor and the detected value of light which is detected by the light receiving sensor.
    Type: Application
    Filed: December 1, 2008
    Publication date: June 4, 2009
    Applicant: Seiko Epson Corporation
    Inventors: Hiroaki JO, Tsukasa EGUCHI, Eiji KANDA, Toshiyuki KASAI
  • Patent number: 7542031
    Abstract: To reduce the variation of luminance between driving modules. Driving modules DR1 to DR3 each have monitor current output circuits, and output monitor current signals MI12, MI21, MI22, and MI31. A monitor unit of a control circuit converts the monitor current signals into monitor data D12, D21, D22, and D31, respectively, and supplies them to a control data generating unit. The control data generating unit generates current control data CTL1 to CTL3 such that the values of the respective monitor current signals are equal to each other and supplies them to the driving modules DR1 to DR3.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: June 2, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Hiroaki Jo, Toshiyuki Kasai
  • Publication number: 20090122090
    Abstract: To adjust brightness of an electro-optic device for each pixel. A data line driving circuit includes a DAC for generating a gray-scale current according to gray-scale data representing gray-scales of pixels, and a DAC for generating a correction current for correcting the brightness of the pixels. The data line driving circuit generates a voltage according to a current obtained by adding the correction current generated in the DAC to the gray-scale current in the DAC and applies the generated voltage to each data line.
    Type: Application
    Filed: January 12, 2009
    Publication date: May 14, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Hiroaki Jo, Toshiyuki Kasai, Takeshi Nozawa
  • Publication number: 20090115769
    Abstract: To simplify s configuration of a current mode DA converter. A data line driving circuit includes DA converting units U1 to Un. Each DA converting unit U1 to Un a voltage DA converting circuit for generating an analog voltage signal Sv based on image data, a V/I converting circuit for converting the analog voltage signal Sv into an analog current signal Si, and a voltage current selector for selecting one of the analog voltage signal Sv and the analog current signal Si based on a pre-charge control signal CTL. In addition, the analog voltage signal Sv outputted from the voltage current selector serves as a pre-charge voltage, and the analog current signal Si serves as a driving current of an OLED element.
    Type: Application
    Filed: December 23, 2008
    Publication date: May 7, 2009
    Applicant: Seiko Epson Corporation
    Inventors: Hiroaki Jo, Toshiyuki Kasai
  • Publication number: 20090079677
    Abstract: The display matrix section 200 has pixel circuits 210 arranged in the form of a matrix, a plurality of gate lines Y1, Y2 . . . that extend in the row direction, and a plurality of data lines X1, X2 . . . that extend in the column direction. The scan lines are connected to a gate driver 300, and the data lines are connected to a data line driver 400. A pre-charging circuit 600 or additional current generation circuit is installed for each data line as means for accelerating the charging or discharging of the data line. For each data line, charging or discharging is accelerated by pre-charging or current addition prior to the completion of the setting of the light emission level in the corresponding pixel circuit 210.
    Type: Application
    Filed: November 10, 2008
    Publication date: March 26, 2009
    Applicant: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Publication number: 20090040444
    Abstract: An optically compensated birefringence mode liquid crystal device includes each pixel electrode that overlaps a part of an adjacent gate line and/or a part of an adjacent source line in a plan view.
    Type: Application
    Filed: July 17, 2008
    Publication date: February 12, 2009
    Applicant: Seiko Epson Corporation
    Inventors: Yutaka TSUCHIYA, Toshiyuki KASAI, Ayae SAWADO, Akihide HARUYAMA
  • Patent number: 7489292
    Abstract: When respective bits of grayscale data Dx1 are ‘0’ which represents black, upon detection, a NOR circuit of a voltage supply circuit sets an output signal active. Then, a transistor is turned on, and a black voltage VBr is supplied to a data line. By this embodiment, since all transistors of a current supply circuit are turned off, a current is not outputted. Meanwhile, in the case in which a grayscale level to be displayed is other than black, a current Idata is outputted from the current supply circuit.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: February 10, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Patent number: 7489310
    Abstract: A data line drive circuit is equipped with a single line driver and a gate voltage generation circuit. The single line driver is constructed such that N groups (where N is an integer 2 or larger) of series connections of drive transistors and switching transistors are connected in parallel. The gate voltage generation circuit includes two transistors constituting a current mirror circuit, a drive transistor, and a constant voltage generation transistor. The range of an output current Iout can be controlled by changing any of the design values of the parameters including: relative values Ka and Kb of the gain coefficient for the transistors, the source voltage VDREF of the gate voltage generation circuit, and the gate signal VRIN of the drive transistor.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: February 10, 2009
    Assignee: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Publication number: 20090033687
    Abstract: A signal processing unit that generates data signals for controlling gray-scale levels of electro-optical elements includes a first D/A conversion unit that generates gray-scale signals from gray-scale data for designating the gray-scale levels of the electro-optical elements; a storage unit that stores correction data indicating correction values with respect to the gray-scale signals; a second D/A conversion unit that has resolution different from that of the first D/A conversion unit, and that generates correction signals from the correction data stored in the storage unit; and a synthesizing unit that synthesizes the gray-scale signals generated by the first D/A conversion unit with the correction signals generated by the second D/A conversion unit to generate the data signals.
    Type: Application
    Filed: September 23, 2008
    Publication date: February 5, 2009
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Toshiyuki Kasai, Hiroaki Jo, Takeshi Nozawa, Hiroshi Horiuchi
  • Patent number: 7486285
    Abstract: To simplify s configuration of a current mode DA converter. A data line driving circuit includes DA converting units U1 to Un. Each DA converting unit U1 to Un a voltage DA converting circuit for generating an analog voltage signal Sv based on image data, a V/I converting circuit for converting the analog voltage signal Sv into an analog current signal Si, and a voltage current selector for selecting one of the analog voltage signal Sv and the analog current signal Si based on a pre-charge control signal CTL. In addition, the analog voltage signal Sv outputted from the voltage current selector serves as a pre-charge voltage, and the analog current signal Si serves as a driving current of an OLED element.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: February 3, 2009
    Assignee: Seiko Epson Corporation
    Inventors: Hiroaki Jo, Toshiyuki Kasai
  • Publication number: 20080316151
    Abstract: The invention provides an electro-optical apparatus that can prevent a shift in a threshold voltage of an amorphous silicon transistor while driving an organic EL device in a pixel circuit including the amorphous silicon transistor. A characteristic-adjustment circuit can be provided, which has a function of returning a shift in the threshold voltage of the amorphous silicon transistor included in the pixel circuit to the original state.
    Type: Application
    Filed: July 23, 2008
    Publication date: December 25, 2008
    Applicant: Seiko Epson Corporation
    Inventors: Toshiyuki Kasai, Yoichi Imamura, Tokuro Ozawa
  • Patent number: 7466311
    Abstract: The display matrix section 200 has pixel circuits 210 arranged in the form of a matrix, a plurality of gate lines Y1, Y2 . . . that extend in the row direction, and a plurality of data lines X1, X2 . . . that extend in the column direction. The scan lines are connected to a gate driver 300, and the data lines are connected to a data line driver 400. A pre-charging circuit 600 or additional current generation circuit is installed for each data line as means for accelerating the charging or discharging of the data line. For each data line, charging or discharging is accelerated by pre-charging or current addition prior to the completion of the setting of the light emission level in the corresponding pixel circuit 210.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: December 16, 2008
    Assignee: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Patent number: 7446738
    Abstract: To provide an electronic circuit, an electro-optical device, and an electronic apparatus, which are capable of producing digital signals having predetermined output values in accordance with digital data. A bit extending circuit 40 is constructed for producing 8-bit digital data in order to change current Im of data line driving signals output from a digital-to-analog converting circuit 30 in a manner of a high order function with respect to 6-bit image data output from a controller. Further, a single line driver 20 is constructed by connecting the bit extending circuit 40 to an input side of the digital-to-analog converting circuit 30.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: November 4, 2008
    Assignee: Seiko Epson Corporation
    Inventor: Toshiyuki Kasai
  • Patent number: 7443540
    Abstract: A signal processing unit that generates data signals for controlling gray-scale levels of electro-optical elements includes a first D/A conversion unit that generates gray-scale signals from gray-scale data for designating the gray-scale levels of the electro-optical elements; a storage unit that stores correction data indicating correction values with respect to the gray-scale signals; a second D/A conversion unit that has resolution different from that of the first D/A conversion unit, and that generates correction signals from the correction data stored in the storage unit; and a synthesizing unit that synthesizes the gray-scale signals generated by the first D/A conversion unit with the correction signals generated by the second D/A conversion unit to generate the data signals.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: October 28, 2008
    Assignee: Seiko Epson Corporation
    Inventors: Toshiyuki Kasai, Hiroaki Jo, Takeshi Nozawa, Hiroshi Horiuchi
  • Publication number: 20080259018
    Abstract: A liquid crystal device has a display mode in which an image is displayed and a non-display mode in which no image is displayed. A scanning line driving device selects a plurality of scanning lines in a predetermined order every unit period. A data line driving device supplies pixel circuits corresponding to a selected one of the scanning lines through the data lines with writing voltages. The data line driving device, in the non-display mode, supplies each data line with the predetermined voltage, as the writing voltage, of which polarity is inverted in a period of integral multiple of the unit period using the reference electric potential as a reference. The scanning line driving device, in the non-display mode, selects each of the scanning lines in a unit period that is longer than the unit period of the display mode.
    Type: Application
    Filed: January 31, 2008
    Publication date: October 23, 2008
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Toshiyuki Kasai