Patents by Inventor Kohji Sakai

Kohji Sakai 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: 20180284270
    Abstract: An object detecting apparatus includes: a light projection unit that is an array light source in which each of a plurality of light emission areas emits light, an optical scanning unit that performs scanning with the light, which is emitted from the light projection unit, in a first direction, and a light receiving unit that receives reflected light which is the light, with which the scanning is performed, being reflected by an object, and an object information acquiring unit that detects presence/absence of the object based on emission timing at which the light is emitted from the light projection unit and light receiving timing at which the light receiving unit receives the reflected light.
    Type: Application
    Filed: June 6, 2018
    Publication date: October 4, 2018
    Inventors: Kohji Sakai, Tadashi Nakamura
  • Patent number: 10071586
    Abstract: A light irradiation apparatus includes an irradiation unit including a light source to emit light to a process-target object, a light source driving circuit to drive the light source, a light source controller to control the light source driving circuit to change a light output level of the light source, and a light spot controller to control energy or energy density of a beam spot of the light on the process-target object depending on an operation mode, and a transition mode that one operation mode is being changed to another mode. The light spot controller sets the energy or energy density during the transition mode lower compared to either of the energy or energy density during the one operation mode before the transition mode and the energy or energy density during the another mode after the transition mode.
    Type: Grant
    Filed: June 16, 2016
    Date of Patent: September 11, 2018
    Assignee: Ricoh Company, Ltd.
    Inventors: Masataka Uehira, Kohji Sakai, Tomoyasu Hirasawa, Tomomi Ishimi
  • Patent number: 10031228
    Abstract: An object detecting apparatus includes: a light projection unit that is an array light source in which each of a plurality of light emission areas emits light, an optical scanning unit that performs scanning with the light, which is emitted from the light projection unit, in a first direction, and a light receiving unit that receives reflected light which is the light, with which the scanning is performed, being reflected by an object, and an object information acquiring unit that detects presence/absence of the object based on emission timing at which the light is emitted from the light projection unit and light receiving timing at which the light receiving unit receives the reflected light.
    Type: Grant
    Filed: October 24, 2014
    Date of Patent: July 24, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kohji Sakai, Tadashi Nakamura
  • Patent number: 9981604
    Abstract: An object detector is provided including a light emitter including at least a light source having a plurality of light emitting areas disposed along a first direction to emit light, an optical scanner configured to scan the light emitted from the light emitter along a second direction that is different from the first direction, a light receiver configured to receive the light that is scanned by the optical scanner and then is reflected at an object, and a controller configured to divide a detection field into a plurality of subareas in a third direction that is orthogonal to the second direction, where a number of partitions of the detection field is variable.
    Type: Grant
    Filed: August 27, 2015
    Date of Patent: May 29, 2018
    Assignee: Ricoh Company, Ltd.
    Inventor: Kohji Sakai
  • Publication number: 20180088255
    Abstract: A microlens array includes N lenses ranging from a 1st lens to an Nth lens and a lens arrangement area. N is a positive integer. The lens arrangement area has the N lenses arranged in array. The lens arrangement area receives light emitted from a light source. An ith (i being 1st to Nth) lens satisfies a conditional expression below: ?20°???20° where ? denotes an angle formed by a main-axis orientation of double refraction and a reference orientation.
    Type: Application
    Filed: September 28, 2017
    Publication date: March 29, 2018
    Inventors: Kohji Sakai, Miho Higuchi, Jun Watanabe
  • Patent number: 9925798
    Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.
    Type: Grant
    Filed: February 23, 2017
    Date of Patent: March 27, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventors: Naoto Watanabe, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo, Masayuki Muranaka
  • Publication number: 20180067308
    Abstract: A light-source device including a light-emitting element to emit light, a light-receiving system, an acquisition unit, a setting unit, and an adjuster. The light-receiving system receives the light emitted from the light emitting element. The acquisition unit acquires a wavelength of the light emitted from the light emitting element. The setting unit sets a target value of an amount of the light received by the light-receiving system based on the wavelength acquired by the acquisition unit. The adjuster adjusts an amount of the light emitted from the light emitting element such that the amount of the light reaches the target value of the light that is set with the setting unit.
    Type: Application
    Filed: August 25, 2017
    Publication date: March 8, 2018
    Inventor: Kohji SAKAI
  • Patent number: 9891432
    Abstract: An object detection device includes: a light projection unit that includes a light source having a plurality of light emitting units that are arranged along at least one direction; a light scanning unit that scans light emitted from the light projection unit along the one direction; a light receiving unit that receives light emitted from the light scanning unit and reflected on an object; and a control unit that determines a light emitting unit to be turned on among the light emitting units, according to a direction of travel of light scanned by the light scanning unit.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: February 13, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventor: Kohji Sakai
  • Publication number: 20180038959
    Abstract: An object detector includes a projector including a light source having a two-dimensionally arranged plurality of light emitter groups, each of the light emitter groups having a plurality of light emitters, a light receiver which receives light emitted from the projector, and reflected by an object, and a light source driver which lights on and lights off each of the light emitter groups of the light source.
    Type: Application
    Filed: October 10, 2017
    Publication date: February 8, 2018
    Inventors: Kazuhiro AKATSU, Tadashi NAKAMURA, Kohji SAKAI
  • Patent number: 9846236
    Abstract: An optical scanner is provided including a light source configured to emit light, a light source driving device configured to drive the light source, a light deflector having at least one rotating reflection plane and configured to deflect the light emitted from the light source to a scanning area, and a light detector configured to output a signal to control a timing at which scanning of the scanning area by the light deflected by the light deflector starts, where the light detector and the scanning area are sequentially scanned in a single scanning by one reflection plane of the light deflector, and the light source driving device drives the light source using a first driving method when the light scans the light detector, and drives the light source using a second driving method that is different from the first driving method when the light scans the scanning area.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: December 19, 2017
    Assignee: Ricoh Company, Ltd.
    Inventors: Shigeaki Imai, Masataka Uehira, Kohji Sakai, Tadashi Nakamura, Yukio Itami
  • Patent number: 9817123
    Abstract: An object detector includes a projector including a light source having a two-dimensionally arranged plurality of light emitter groups, ach of the light emitter groups having a plurality of light emitters, a light receiver which receives light emitted from the projector, and reflected by an object, and a light source driver which lights on and lights off each of the light emitter groups of the light source.
    Type: Grant
    Filed: December 7, 2016
    Date of Patent: November 14, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Akatsu, Tadashi Nakamura, Kohji Sakai
  • Publication number: 20170276546
    Abstract: A wavelength estimation device including a light detector to receive light emitted from a light source and an estimation unit. The estimation unit estimates a wavelength of the light based on an amount of light received by the light detector.
    Type: Application
    Filed: March 9, 2017
    Publication date: September 28, 2017
    Inventors: Kohji SAKAI, Kazuhiro Akatsu
  • Publication number: 20170160667
    Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.
    Type: Application
    Filed: February 23, 2017
    Publication date: June 8, 2017
    Inventors: Naoto WATANABE, Toshiaki TOKITA, Kohji SAKAI, Nobuaki KUBO, Masayuki MURANAKA
  • Patent number: 9625711
    Abstract: An optical scanning apparatus includes a light source, an optical deflector having a rotary polygon mirror to deflect a light beam from the light source, a scanning optical system configured to focus the light beam deflected by the optical deflector on a target surface, a sync detecting sensor configured to determine a write start timing on the target surface, and a processing unit configured to correct detection data of the sync detecting sensor based on a measured value of a time needed for one revolution of the rotary polygon mirror.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: April 18, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Naoto Watanabe, Toshiaki Tokita, Kohji Sakai, Nobuaki Kubo, Masayuki Muranaka
  • Publication number: 20170082747
    Abstract: An object detector includes a projector including a light source having a two-dimensionally arranged plurality of light emitter groups, ach of the light emitter groups having a plurality of light emitters, a light receiver which receives light emitted from the projector, and reflected by an object, and a light source driver which lights on and lights off each of the light emitter groups of the light source.
    Type: Application
    Filed: December 7, 2016
    Publication date: March 23, 2017
    Inventors: KAZUHIRO AKATSU, Tadashi Nakamura, Kohji Sakai
  • Patent number: 9568605
    Abstract: An object detector includes a projector including a light source having a two-dimensionally arranged plurality of light emitter groups, each of the light emitter groups having a plurality of light emitters, a light receiver which receives light emitted from the projector, and reflected by an object, and a light source driver which lights on and lights off each of the light emitter groups of the light source.
    Type: Grant
    Filed: November 26, 2014
    Date of Patent: February 14, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Kazuhiro Akatsu, Tadashi Nakamura, Kohji Sakai
  • Patent number: 9557563
    Abstract: An optical scanning device includes: a light source that emits a laser beam modulated and driven according to an image forming signal; a scanning optical system that includes a polygon mirror to scan a surface of a photoconductor with the laser beam from the light source; a surface identifying unit that associates a sub-scanning position by the polygon mirror with each surface of the polygon mirror; and a light-amount adjusting unit that adjusts a light amount of the light source according to the sub-scanning position, for each surface of the polygon mirror.
    Type: Grant
    Filed: May 27, 2015
    Date of Patent: January 31, 2017
    Assignee: RICOH COMPANY, LTD.
    Inventors: Mitsuo Suzuki, Kohji Sakai
  • Publication number: 20170001459
    Abstract: A light irradiation apparatus includes an irradiation unit including a light source to emit light to a process-target object, a light source driving circuit to drive the light source, a light source controller to control the light source driving circuit to change a light output level of the light source, and a light spot controller to control energy or energy density of a beam spot of the light on the process-target object depending on an operation mode, and a transition mode that one operation mode is being changed to another mode. The light spot controller sets the energy or energy density during the transition mode lower compared to either of the energy or energy density during the one operation mode before the transition mode and the energy or energy density during the another mode after the transition mode.
    Type: Application
    Filed: June 16, 2016
    Publication date: January 5, 2017
    Inventors: Masataka UEHIRA, Kohji SAKAI, Tomoyasu HIRASAWA, Tomomi ISHIMI
  • Patent number: 9448436
    Abstract: In the present invention, a backlight (3) serving as a planar light source unit is equipped with: multiple LEDs (12); and a bottom plate (11a) having a mounting surface (11a1). The multiple LEDs (12) are two-dimensionally arranged on the mounting surface (11a1) within a rectangular area (RA) that is smaller than the bottom plate (11a). In addition, the arrangement density of the LEDs in the rectangular area (RA) is lower at the center part (Rc) than at the peripheral part (Rp). The rectangular area (RA) has a corner area, where at least one LED (12) is provided, at each of the four corners thereof. The LEDs (12) positioned in the respective corner areas are installed such that the central axes of the LEDs lean toward the periphery side of the rectangular area (RA) with respect to the direction perpendicular to the mounting surface (11a1).
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: September 20, 2016
    Assignee: SHARP KABUSHIKI KAISHA
    Inventor: Kohji Sakai
  • Publication number: 20160261090
    Abstract: A semiconductor laser driving apparatus for driving a semiconductor laser serving as a light source for optical scanning, the semiconductor laser driving apparatus includes: first and second switching elements that are each capable of switching energization of the semiconductor laser ON/OFF; a first pulse generation unit that intermittently outputs first driving pulses to the first switching element in a first time slot; and a second pulse generation unit that outputs a second driving pulse to the second switching element in a second time slot different from the first time slot.
    Type: Application
    Filed: March 2, 2016
    Publication date: September 8, 2016
    Inventors: Kohji Sakai, Masataka Uehira, Shigeaki Imai, Tadashi Nakamura