Patents by Inventor Takuma Hiramatsu

Takuma Hiramatsu 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: 20190195993
    Abstract: An optical sensor configured to reduce a measurement time while the accuracy of the optical sensor is maintained is realized. An initial configuration circuit (19) includes a counter configured to perform counting of the number of pulse outputs from a first light-receiving unit (11) in first to nth regions obtained by dividing each cycle of a reference clock into n equal parts, determines, among the first to nth regions, a region in which a counter value is largest, and the initial configuration circuit causes a first DLL circuit (17) to perform a converging operation to the region determined.
    Type: Application
    Filed: June 9, 2017
    Publication date: June 27, 2019
    Inventors: HIDEKI SATO, YOSHIKI IKUTA, TAKAYUKI SHIMIZU, TAKUMA HIRAMATSU
  • Publication number: 20190159309
    Abstract: There is provided a VCSEL drive circuit that causes a VCSEL to emit pulsed light in a light emission period, including a drive adjustment unit that adjust a first voltage which is a voltage of drains of a PMOS transistor and an NMOS transistor in a constant current circuit and a second voltage which is a voltage of a drain of an NMOS transistor that drives the VCSEL to be the same voltage in a pre-light emission period before the light emission period.
    Type: Application
    Filed: October 9, 2018
    Publication date: May 23, 2019
    Applicants: SHARP KABUSHIKI KAISHA, SHARP KABUSHIKI KAISHA
    Inventors: TAKAYUKI SHIMIZU, YOSHIKI IKUTA, HIDEKI SATO, TAKUMA HIRAMATSU
  • Publication number: 20190146086
    Abstract: An optical sensor includes a time difference extraction circuit for extracting a time difference based on the distance to a target on the basis of a first received light pulse signal from a first light receiving unit, a reference cycle, and a second received light pulse signal from a second light receiving unit, and a determination circuit for determining whether a crosstalk value can be calculated on the basis of the time difference extracted by the time difference extraction circuit and the reference cycle.
    Type: Application
    Filed: September 29, 2018
    Publication date: May 16, 2019
    Inventors: HIDEKI SATO, YOSHIKI IKUTA, TAKAYUKI SHIMIZU, TAKUMA HIRAMATSU
  • Publication number: 20190129012
    Abstract: A selection circuit selects one of digital values respectively output from a TDC 1 and a TDC 2. A histogram generation circuit generates a histogram indicating a relationship between a bin number and a frequency by counting up the frequency of the bin number according to the digital value selected by the selection circuit.
    Type: Application
    Filed: September 29, 2018
    Publication date: May 2, 2019
    Inventors: YOSHIKI IKUTA, TAKUMA HIRAMATSU, TAKAYUKI SHIMIZU, HIDEKI SATO
  • Publication number: 20190129015
    Abstract: An optical sensor of the present invention changes a light-emitting period of a light-emitting element and a period of a reference clock that is used by a time difference extracting circuit, depending on whether or not a digital value that is output from a first digital calculating portion exceeds a reference value in a determination period. With this, there is achieved an optical sensor capable of maintaining both of measurement accuracy at short distance and measurement accuracy at long distance when a housing panel is present between the optical sensor and a detection target.
    Type: Application
    Filed: April 21, 2017
    Publication date: May 2, 2019
    Inventors: YOSHIKI IKUTA, HIDEKI SATO, TAKUMA HIRAMATSU, TAKAYUKI SHIMIZU
  • Publication number: 20190094342
    Abstract: A TOF ranging sensor according to Embodiment includes: a light-emitting unit that radiates light beams to subspaces; a light-receiving unit that receives light and forms images of the light on light-receiving elements allocated to the subspaces; and a space control unit that independently controls each element group that includes a light-emitting element and a light-receiving element that are allocated to a common one of the subspaces.
    Type: Application
    Filed: September 25, 2018
    Publication date: March 28, 2019
    Inventors: TAKUMA HIRAMATSU, TAKAYUKI SHIMIZU
  • Publication number: 20180095167
    Abstract: Disturbance noise is distinguished and an appropriate detection result is output in accordance with a state of each disturbance noise. A signal processing circuit (11) of a photodetection device (101) includes non-synchronous detection units (112, 113) that detect existence of a light reception signal which is not synchronous with a light emitting drive timing in at least one of a case where it is determined that a value of the light reception signal exceeds a predetermined first threshold and a case where the value of the light reception signal becomes less than a predetermined second threshold in a non-synchronous detection period except a synchronous detection period in a detection period in the signal processing circuit (11).
    Type: Application
    Filed: October 21, 2015
    Publication date: April 5, 2018
    Inventors: YASUYUKI SHIRASAKA, TAKUMA HIRAMATSU
  • Patent number: 8217335
    Abstract: An optical modulation-type detection device has a noise detection mode having (i) an offset canceling (hereinafter referred to as “OC”) period in which (a) the light-reception signal pathway of a pulse signal converting section is cut off so that an offset of the pulse signal converting section is suppressed and (b) the light-reception signal pathway of the pulse signal converting section is reconnected while a state in which the offset is suppressed is being maintained, at an end of the OC period, and (ii) an asynchronous reception period in which whether or not asynchronous reception occurs is detected after the first period, and an object detection mode having a synchronous reception period in which whether or not synchronous reception occurs is detected after the asynchronous reception is not detected in the noise detection mode.
    Type: Grant
    Filed: August 27, 2009
    Date of Patent: July 10, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takuma Hiramatsu, Ryohhei Tada, Isamu Kawabe, Naruichi Yokogawa
  • Publication number: 20100067017
    Abstract: An optical modulation-type detection device has a noise detection mode having (i) an offset canceling (hereinafter referred to as “OC”) period in which (a) the light-reception signal pathway of a pulse signal converting section is cut off so that an offset of the pulse signal converting section is suppressed and (b) the light-reception signal pathway of the pulse signal converting section is reconnected while a state in which the offset is suppressed is being maintained, at an end of the OC period, and (ii) an asynchronous reception period in which whether or not asynchronous reception occurs is detected after the first period, and an object detection mode having a synchronous reception period in which whether or not synchronous reception occurs is detected after the asynchronous reception is not detected in the noise detection mode.
    Type: Application
    Filed: August 27, 2009
    Publication date: March 18, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Takuma HIRAMATSU, Ryohhei TADA, Isamu KAWABE, Naruichi YOKOGAWA
  • Patent number: 7295592
    Abstract: A light source device for radiating a stimulated emission from a semiconductor laser to outside via a multiple scattering optical system, which system has a first region located adjacent to the semiconductor laser and a second region that abuts on the first region and reaches the outside. The first region contains scatterers at a higher density than the second region does. The light source device has an amount of near-field pattern speckles ?PAR of 3×10?3 or more. The second region may have a lens portion as a magnifier for at least a principle part of a secondary planar light source formed at an interface between the first and second regions.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: November 13, 2007
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Takuma Hiramatsu, Atsushi Shimonaka, Naoyuki Morimoto
  • Patent number: 7099589
    Abstract: An optical wireless local area network according to the present invention is an optical wireless local area network for interconnecting a plurality of terminals having a line-of-sight optical communication function. In the optical wireless local area network, a base station including an angle diversity light reception function and a plurality of optical transmitters each having directionality is provided. The intensity of each of the plurality of optical transmitters can be separately modulated.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: August 29, 2006
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takuma Hiramatsu
  • Publication number: 20050226636
    Abstract: A light source device for radiating a stimulated emission from a semiconductor laser to outside via a multiple scattering optical system, which system has a first region located adjacent to the semiconductor laser and a second region that abuts on the first region and reaches the outside. The first region contains scatterers at a higher density than the second region does. The light source device has an amount of near-field pattern speckles ?PAR of 3×10?3 or more. The second region may have a lens portion as a magnifier for at least a principle part of a secondary planar light source formed at an interface between the first and second regions.
    Type: Application
    Filed: March 3, 2003
    Publication date: October 13, 2005
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Takuma Hiramatsu, Atsushi Shimonaka, Naoyubi Morimoto
  • Publication number: 20050122720
    Abstract: A light source apparatus is provided with a light scattering region 5 containing light scattering particles 6 disposed in a part of a region extending from a semiconductor light-emitting laser chip 1 to an external space. An asymmetry factor g of the light scattering particles 6 and a transport optical depth <n> of the light scattering region 5 are set so that their product g.<n> satisfies a following condition: 2?g·<n>?40 The light source apparatus is of small-size and low-cost and can ensure safety of human eyes as well as obtain a high optical output.
    Type: Application
    Filed: November 17, 2004
    Publication date: June 9, 2005
    Inventors: Atsushi Shimonaka, Takuma Hiramatsu
  • Patent number: 5880028
    Abstract: A ridge waveguide type distributed feedback semiconductor laser device includes a diffraction grating formed on a surface of a semiconductor wafer, a semiconductor layer formed on the diffraction grating, the semiconductor layer serving to alleviate the irregularity of the diffraction grating, and a stripe-like ridge having a cladding layer and a contact layer formed on the semiconductor layer. Also, a method for manufacturing the ridge waveguide type distributed feedback semiconductor laser device is disclosed.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: March 9, 1999
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kei Yamamoto, Takuma Hiramatsu, Koji Takahashi, Mototaka Taneya