Patents by Inventor Akihiro Asada

Akihiro Asada 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: 7575081
    Abstract: A work vehicle includes a traveling vehicle body and a hood provided at a front portion of the vehicle body for covering an engine room. The hood includes a front face having a plurality of first air vent holes and right and left side faces each having a plurality of second air vent holes. A radiator is mounted inside the hood, ambient air being drawn in through the first and second air vent holes toward the radiator. A vent hole area ratio of each side face of the hood determined by the second air vent holes is set smaller than a vent hole area ratio of the front face of the hood determined by the first air vent holes.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: August 18, 2009
    Assignee: Kubota Corporation
    Inventors: Mitsuhiko Obe, Akihiro Asada, Takashi Kobayashi
  • Patent number: 7573797
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: August 11, 2009
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Patent number: 7570564
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: August 4, 2009
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Patent number: 7570565
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: August 4, 2009
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Publication number: 20090073829
    Abstract: A hybrid LDD includes a read channel to selectively output a read current, a plurality of write channels, each to selectively output a different write current, and an oscillator channel to selectively output an oscillator current. Additionally, the hybrid LDD includes programmable LDD controller that receives the plurality of enable signals from the external controller, and based on the enable signals, controls timing of the currents output by at least the write channels. The programmable LDD controller can also control timing of the currents output by the read and oscillator channels, based on the enable signals. Further and alternative embodiments are also provided.
    Type: Application
    Filed: November 25, 2008
    Publication date: March 19, 2009
    Applicant: Intersil Americas Inc.
    Inventors: Theodore D. Rees, Akihiro Asada, D. Stuart Smith
  • Patent number: 7499478
    Abstract: An optical disk apparatus uses a laser driver which can measure the frequency of the high-frequency superimposed current of the semiconductor laser simply and accurately. The apparatus includes a semiconductor laser which emits a laser beam onto the optical disk, a laser driver which drives the semiconductor laser with a current, with the high-frequency current being superimposed thereon, and measures the frequency of the high-frequency current, and a main controller which controls the frequency of the high-frequency current produced by the laser driver by using the frequency measured by the laser driver.
    Type: Grant
    Filed: September 9, 2004
    Date of Patent: March 3, 2009
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Makoto Nihei, Toshimitsu Kaku, Akihiro Asada, Takashi Hoshino
  • Patent number: 7492686
    Abstract: Embodiments of the present invention relate to systems and methods for providing flexible multipulse strategies. In specific embodiments, a plurality of multipulse location registers are dedicated to storing multipulse location information. Each of a plurality of different mark-lengths that can result in at least one multipulse is mapped to one or more bit location within the multipulse location registers, such that a unique multipulse execution strategy can be defined for each of the plurality of different mark-lengths. Each bit location within the multipulse location registers can contain a first type of bit or a second type of bit. The first type of bit is used to indicate where to execute a multipulse, and the second type of bit is used to indicate where to not execute a multipulse. This abstract is not intended to be a complete description of the various embodiments of the present invention.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: February 17, 2009
    Assignee: Intersil Americas Inc.
    Inventors: Miguel Gabino Perez, Alexander Fairgrieve, Akihiro Asada
  • Publication number: 20080068947
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Application
    Filed: October 26, 2007
    Publication date: March 20, 2008
    Applicants: HITACHI, LTD, HITACHI-LG DATA STORAGE, INC.
    Inventors: Akihiro ASADA, Masaaki KUREBAYASHI
  • Publication number: 20080056078
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Application
    Filed: October 26, 2007
    Publication date: March 6, 2008
    Applicants: HITACHI, LTD., HITACHI-LG DATA STORAGE, INC.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Publication number: 20080056090
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Application
    Filed: October 26, 2007
    Publication date: March 6, 2008
    Applicants: HITACHI, LTD., HITACHI-LG DATA STORAGE, INC.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Publication number: 20080008062
    Abstract: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a state machine that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.
    Type: Application
    Filed: May 16, 2007
    Publication date: January 10, 2008
    Applicant: INTERSIL AMERICAS INC.
    Inventors: Theodore D. Rees, Akihiro Asada
  • Publication number: 20080008066
    Abstract: Provided herein are hybrid laser diode drivers (LDDs) that drive a laser diode in response to receiving enable signals from a controller. In accordance with specific embodiments, a hybrid LDD includes a read channel to selectively output a read current, one or more write channel each to selectively output a write current, and an oscillator channel to selectively output an oscillator current. Additionally, in specific embodiments the hybrid LDD includes a decoder that receives the enable signals from the controller, and based on the enable signals, controls timing of the currents output by the read, write and oscillator channels.
    Type: Application
    Filed: May 16, 2007
    Publication date: January 10, 2008
    Applicant: INTERSIL AMERICAS INC.
    Inventors: Theodore D. Rees, Akihiro Asada
  • Publication number: 20070266812
    Abstract: A speed changing structure for a work vehicle, comprising a travel speed changing device having a plurality of speed change positions, a manually operated speed changing lever (63), control means (64) for controlling the travel speed changing device, and a manually operable operating part (65) provided to the speed changing lever (63), wherein the control means (64) has a first speed changing mode for operating the travel speed changing device in single steps so as to follow the operation of the speed changing lever (63), and a second speed changing mode for operating the travel speed changing device without passing through intermediate speed change positions to a speed change position that corresponds to the operating position after the speed changing lever (63) has been moved from the speed change position that corresponds to the operating position prior to the speed changing lever (63) being operated; and the control means (64) operates the travel speed changing device in the first speed changing mode when
    Type: Application
    Filed: March 21, 2007
    Publication date: November 22, 2007
    Applicant: Kubota Corporation
    Inventor: Akihiro Asada
  • Patent number: 7298681
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: November 20, 2007
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Publication number: 20060280089
    Abstract: Embodiments of the present invention relate to systems and methods for providing flexible multipulse strategies. In specific embodiments, a plurality of multipulse location registers are dedicated to storing multipulse location information. Each of a plurality of different mark-lengths that can result in at least one multipulse is mapped to one or more bit location within the multipulse location registers, such that a unique multipulse execution strategy can be defined for each of the plurality of different mark-lengths. Each bit location within the multipulse location registers can contain a first type of bit or a second type of bit. The first type of bit is used to indicate where to execute a multipulse, and the second type of bit is used to indicate where to not execute a multipulse. This abstract is not intended to be a complete description of the various embodiments of the present invention.
    Type: Application
    Filed: September 22, 2005
    Publication date: December 14, 2006
    Applicant: Intersil Americas Inc.
    Inventors: Miguel Perez, Alexander Fairgrieve, Akihiro Asada
  • Publication number: 20060146679
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Application
    Filed: February 23, 2006
    Publication date: July 6, 2006
    Applicants: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Patent number: 7038989
    Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: May 2, 2006
    Assignees: Hitachi, Ltd., Hitachi-LG Data Storage, Inc.
    Inventors: Akihiro Asada, Masaaki Kurebayashi
  • Patent number: 6954410
    Abstract: A laser waveform generation function is provided in a laser driving waveform generator 2 near a laser 3. A recording clock generator 9 is included in the laser driving waveform generator 2 to generate a clock with a frequency higher than that of a synchronizing clock 202. This allows a recording laser current (waveform) to be generated without transmission of a high frequency signal from the modulator 6. Further, because the synchronizing clock 202 is stopped upon a reproduction operation including reproduction operation in an ID unit, undesired effects on a reproduction operation such as ID reproduction can be reduced. Because the response speed of the recording clock generator 9 can be changed, a high precision clock can be generated. Thus, a high-precision recording laser current (waveform) can be generated.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: October 11, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Hoshino, Toshimitsu Kaku, Akihiro Asada, Takehiko Sekine
  • Patent number: D527743
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: September 5, 2006
    Assignee: Kubota Corporation
    Inventors: Akihiro Asada, Junta Kuwae
  • Patent number: D538306
    Type: Grant
    Filed: August 27, 2004
    Date of Patent: March 13, 2007
    Assignee: Kubota Corporation
    Inventors: Akihiro Asada, Junta Kuwae