Patents by Inventor Kouji Nakahara

Kouji Nakahara 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: 6943922
    Abstract: An image reading apparatus is provided which is capable of reading an original document at a higher speed. M pieces of lines on the surface of the original document can be simultaneously read by M pieces of line-like strings of light sensing devices making up a CCD (Charge-Coupled Device) having an interval represented by N pieces of lines to be read. When simultaneous reading is completed, the original document is moved to a line existing apart by L pieces of lines from the lines that have been read. While the original document is moving, image signals of lines that have been read are A/D (analog to digital) converted and then stored to memory regions. Simultaneous reading operation and subsequent storing are sequentially performed on lines on which the line-like strings of light sensing devices are placed.
    Type: Grant
    Filed: April 25, 2001
    Date of Patent: September 13, 2005
    Assignee: NEC Corporation
    Inventors: Tetsuichiro Yamamoto, Kouji Nakahara
  • Patent number: 6931039
    Abstract: Optical transmitter equipment and a semiconductor laser device are provided. In one example, optical transmitter equipment includes a semiconductor laser driven by a direct-modulated method. The optical transmitter equipment comprises at least a semiconductor laser, the semiconductor laser having an active layer for laser oscillation and a clad region for optical confinement; an emission device capable of supplying optical energy to the active layer in the semiconductor laser; and a drive circuit for the semiconductor laser. The emission device is configured to supply optical energy corresponding to a bias current in the semiconductor laser to the active layer in the semiconductor laser.
    Type: Grant
    Filed: April 14, 2003
    Date of Patent: August 16, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Kouji Nakahara, Ryoji Takeyari
  • Publication number: 20050127383
    Abstract: Laser diodes containing aluminum at high concentration in an active layer have been usually suffered from remarkable facet deterioration along with laser driving operation and it has been difficult for the laser diodes to attain high reliability. An aluminum oxide film lacking in oxygen is formed adjacent to the semiconductor on an optical resonator facet, by which facet deterioration can be minimized and, accordingly, the laser diode can be operated with no facet deterioration at high temperature for long time and a laser diode of high reliability can be manufactured at a reduced cost.
    Type: Application
    Filed: February 6, 2004
    Publication date: June 16, 2005
    Inventors: Takeshi Kikawa, Kouji Nakahara, Etsuko Nomoto
  • Publication number: 20040099859
    Abstract: The prior art distributed feedback laser having an InGaAlAs active layer involves a problem that its laser characteristics are deteriorated at high temperature due to the high device resistance. According to the present invention, a ridge type laser is fabricated by: forming an InGaAlAs-MQW layer 104 on a n-type InP substrate 101; growing a p-type InGaAlAs-GRIN-SCH layer 105, a p-type InAlAs electron stopping layer 106 and a p-type grating layer 107 in this order on the InGaAlAs-MQW layer 104; forming a grating; and regrowing a p-type InP cladding layer 108 and a p-type InGaAs contact layer in this order. The concave depth of the grating is smaller than the thickness of the p-type grating layer 107.
    Type: Application
    Filed: June 27, 2003
    Publication date: May 27, 2004
    Inventors: Kouji Nakahara, Tomonobu Tsuchiya, Akira Taike, Kazunori Shinoda
  • Publication number: 20040028100
    Abstract: Optical transmitter equipment and a semiconductor laser device are provided. In one example, optical transmitter equipment includes a semiconductor laser driven by a direct-modulated method. The optical transmitter equipment comprises at least a semiconductor laser, the semiconductor laser having an active layer for laser oscillation and a clad region for optical confinement; an emission device capable of supplying optical energy to the active layer in the semiconductor laser; and a drive circuit for the semiconductor laser. The emission device is configured to supply optical energy corresponding to a bias current in the semiconductor laser to the active layer in the semiconductor laser.
    Type: Application
    Filed: April 14, 2003
    Publication date: February 12, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Kouji Nakahara, Ryoji Takeyari
  • Patent number: 6639241
    Abstract: In a ridge type semiconductor optical device in which both sides of the mesa stripe are recessed each into a rectangular shape by a depth reaching an active layer, a semiconductor optical device having a structure in which a structure that obstructs conductivity is disposed at a portion on the bottom of a rectangular shape. The structure that obstructs conductivity is attained, for example, by a structure in which impurities are ion implanted into a semiconductor.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: October 28, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kouji Nakahara, Tsurugi Sudo
  • Publication number: 20030165169
    Abstract: The present invention provides a highly reliable ridge-waveguide semiconductor laser diode and an optical module. The p-side electrode of the ridge-waveguide laser diode has a first conductor layer region and a second conductor layer region formed on the first conductor layer region. At least one of facets of the second conductor layer region is recessed inward from a reflection facet. Thus, the ridge-waveguide semiconductor laser diode has a structure in which strain which is caused by the electrode stress to be applied on the diode facet is reduced and the saturable absorption does not occur. The ridge-waveguide semiconductor laser diode thus obtained is highly reliable, and the optical module using the same is remarkably high in reliability.
    Type: Application
    Filed: August 28, 2002
    Publication date: September 4, 2003
    Applicant: OpNext Japan, Inc.
    Inventors: Etsuko Nomoto, Kouji Nakahara, Shinji Tsuji, Makoto Shimaoka
  • Patent number: 6563608
    Abstract: A document reading apparatus includes a light-source assembly which can provide the reduced number of parts and the effective use of light. The light-source assembly includes a plate and a holder. The plate has a reflective surface at one side thereof and a fixing surface at the other side thereof, wherein the plate is fixed at the fixing surface such that the reflective surface is placed in a predetermined direction. The holder is provided on the reflective surface of the one side of the plate. The holder holds and fixes the light source substantially parallel to the reflective surface.
    Type: Grant
    Filed: June 1, 1999
    Date of Patent: May 13, 2003
    Assignee: NEC Corporation
    Inventors: Kouji Nakahara, Hiroya Ooki, Tetsuichirou Yamamoto
  • Publication number: 20030042476
    Abstract: The subject of the disclosed technique is as follows: a structure in a ridge type semiconductor optical device having both high operation speed and high reliability together is attained.
    Type: Application
    Filed: February 12, 2002
    Publication date: March 6, 2003
    Inventors: Kouji Nakahara, Tsurugi Sudo
  • Patent number: 6522424
    Abstract: An image data transfer system and method enable scan time and transfer time of the image data to be adjusted appropriately without lacking a part of the image data, suitable for low price. A data segmentation device segments the image data from a scan device into high order n bits and low order (N−n) bits, subsequently, transferring the high order n bits toward a data transfer device at the same time when the scan device scans a manuscript, and transferring the low order (N−n) bits toward a memory device. The data transfer device transfers the high order n bits of the image data toward a personal computer at the same time when the scan device scans the manuscript. The memory device stores therein the low order (N−n) bits of the image data temporarily. Furthermore, the data transfer device scans the low order (N−n) bits of the image data from the memory device to transfer toward the personal computer after transfer of the high order n bits.
    Type: Grant
    Filed: February 10, 1999
    Date of Patent: February 18, 2003
    Assignee: Nec Corporation
    Inventors: Kouji Nakahara, Tetsuichirou Yamamoto
  • Publication number: 20020071462
    Abstract: A semiconductor laser having high speed modulation function over a wide temperature range can be attained by making an active layer region of a semiconductor laser as a multiple quantum well structure of InGaAlAs or InGaAs material system, and defining the bandgap wavelength of the barrier layer to less than 950 nm, or alternatively, by making the bandgap wavelength of a barrier to less than 1000 nm and the bandgap wavelength optical guide layer substantially equal with or shorter than that of the barrier layer in a structure having a multiple quantum well of the same material system having an active layer and an optical guide layer in adjacent therewith.
    Type: Application
    Filed: February 20, 2001
    Publication date: June 13, 2002
    Inventors: Daisaku Takemoto, Etsuko Nomoto, Tomonobu Tsuchiya, Kouji Nakahara
  • Publication number: 20020063785
    Abstract: An image reading apparatus is provided which is capable of reading an original document at a higher speed. M pieces of lines on the surface of the original document can be simultaneously read by M pieces of line-like strings of light sensing devices making up a CCD (Charge-Coupled Device) having an interval represented by N pieces of lines to be read. When simultaneous reading is completed, the original document is moved to a line existing apart by L pieces of lines from the lines that have been read. While the original document is moving, image signals of lines that have been read are A/D (analog to digital) converted and then stored to memory regions. Simultaneous reading operation and subsequent storing are sequentially performed on lines on which the line-like strings of light sensing devices are placed.
    Type: Application
    Filed: April 25, 2001
    Publication date: May 30, 2002
    Applicant: NEC CORPORATION
    Inventors: Tetsuichiro Yamamoto, Kouji Nakahara
  • Patent number: 6396044
    Abstract: To achieve a reduction in the cost of components and a reduction in assembly steps in a production line, the number of parts is reduced in an image reading apparatus. An image reading apparatus includes a casing which is provided with a unit to which light reflected from an original document surface is incident, a lens for converging the reflected light, an image sensor to which the reflected light which has been converged by the lens is incident, and a plurality of reflectors disposed between the light incident unit and the lens for defining an optical path for the reflected light. The reflectors are formed on the inner surface of the casing in a plurality of positions by vacuum depositing aluminum on the inner surface.
    Type: Grant
    Filed: December 21, 1999
    Date of Patent: May 28, 2002
    Inventors: Hiroya Ooki, Tetsuichirou Yamamoto, Kouji Nakahara
  • Publication number: 20010024462
    Abstract: In order to realize a low-cost and small-sized optical transmitting module, which overcomes a bad influence of fluctuation in environment temperature on a FP laser for the optical communication, a heater 2 is sandwiched between the sub-mount 5 and the semiconductor laser 1 to increase temperature of the semiconductor 1 through the use of the heater 2. The temperature of the semiconductor laser 1 is sensed through the used of the temperature sensor 6, and the heater 2 is controlled through the use of the temperature control module 3 to keep the temperature of the semiconductor laser 1 higher than room temperature.
    Type: Application
    Filed: December 20, 2000
    Publication date: September 27, 2001
    Inventors: Kouji Nakahara, Kazuhisa Uomi