Patents by Inventor Takahiro Yoshikawa

Takahiro Yoshikawa 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: 8526871
    Abstract: The fixing device includes a fixing roller, a separation roller, an endless fixing belt, and a pressing roller. The fixing roller includes a first elastic layer as a surface layer and has a roller hardness A. The separation roller includes a second elastic layer as a surface layer and has a roller hardness B smaller than the roller hardness A of the fixing roller. The endless fixing belt is wound around the fixing roller and the separation roller. The pressing roller is pressed against the fixing roller and the separation roller via the fixing belt to form a nip portion between the fixing belt and the pressing roller through which the recording medium bearing the toner image passes. The pressing roller includes a third elastic layer as a surface layer and has a roller hardness C not smaller than the roller hardness A of the fixing roller.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: September 3, 2013
    Assignee: Ricoh Company, Ltd.
    Inventor: Takahiro Yoshikawa
  • Publication number: 20130155335
    Abstract: An illuminating device (3) includes light emitting diodes (light sources) (5) and a light guide plate (7) that directs light from the light emitting diodes (5) in a predetermined propagation direction and emits the light to a liquid crystal panel (object to be irradiated) (2). The illuminating device includes a chassis (case) (9) that houses the light emitting diodes (5) and the light guide plate (7). The chassis (9) is provided with a supporting member (support) (12) for supporting the light guide plate (7).
    Type: Application
    Filed: May 11, 2011
    Publication date: June 20, 2013
    Applicant: Sharpe Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Patent number: 8463150
    Abstract: A fixing device includes a fuser member, a pressure member, a first motor, a second motor, a pressure adjuster, and a controller. The fuser member defines a first heatable surface. The pressure member defines a second heatable surface. The first motor is connected to the fuser member to rotate at a first rotation rate to drive the first surface at a first conveyance speed. The second motor is connected to the pressure member to rotate at a second rotation rate to drive the second surface at a second conveyance speed. The pressure adjuster presses the pressure member against the fuser member at a variable pressure to form a fixing nip with a variable width extending along the conveyance path. The controller is connected to the first and second motors to adjust at least one of the first and second rotation rates relative to the other.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: June 11, 2013
    Assignee: Ricoh Company Limited
    Inventor: Takahiro Yoshikawa
  • Patent number: 8436961
    Abstract: A backlight unit including holding members capable of preventing occurrence of a noise caused when the members are brought into contact with an optical member such as a diffusion plate. A backlight unit (4) includes a chassis (14) including a surface (14a) housing light sources (12), an optical member (11) having a flat plate shape and disposed above the light sources, and members (25) holding the optical member and attached to the housing surface, wherein each of the holding members includes a portion (25a) holding the optical member, and paired leg portions (25b and 25c) extending from the holding portion, elastically deformable in a direction in which the leg portions approach/leave each other and including paired foot portions (25d) disposed at lower ends of the leg portions, at least one of the paired foot portions being placed in a manner slidable on the housing surface in the approaching/leaving direction.
    Type: Grant
    Filed: March 31, 2010
    Date of Patent: May 7, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Publication number: 20130108336
    Abstract: A fixing device includes a first driving system connected to a fixing roller and a separation roller and a second driving system connected to a pressing roller pressed against the fixing roller and the separation roller via a fixing belt. In the first driving system, a first transmission transmits a first driving force generated by a first motor to the fixing roller and the separation roller, and includes a first one-way clutch via which the first driving force is transmitted to the fixing roller. In the second driving system, a second transmission transmits a second driving force generated by a second motor to the pressing roller. When a circumferential velocity of the pressing roller is greater than a circumferential velocity of the fixing roller, the first one-way clutch idles to rotate the fixing roller in accordance with rotation of the pressing roller.
    Type: Application
    Filed: December 18, 2012
    Publication date: May 2, 2013
    Inventor: Takahiro Yoshikawa
  • Patent number: 8425069
    Abstract: A lighting device 12 of the present invention includes a plurality of light sources 17 and an optical member arranged closer to the light-exiting portion 15z than the light sources 17. The optical member 15 includes a prism diffuser plate 15a for diffusing light emitted from the light sources 17 and exiting from a lens sheet 15c arranged closer to the light-exiting portion 15z than the prism diffuser plate 15a. The prism diffuser plate 15a has prisms on a surface located on a side closer to the light-exiting portion 15z. The lens sheet 15c has convex lenses 62 on a surface closer to the light-exiting portion 15z.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: April 23, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Shuki Yamamoto, Yasumori Kuromizu, Kaori Yamamoto, Takahiro Yoshikawa
  • Patent number: 8371720
    Abstract: In a diffusion sheet (46), first reflection areas (AR1) with high reflectance and second reflection areas (AR2) with low reflectance are alternately arranged parallel to each other on a light receiving surface (46R), and third reflection areas (AR3) with high reflectance and fourth reflection areas (AR4) with low reflectance are alternately arranged parallel to each other on an light emitting surface (46F). In the diffusion sheet (46), the first reflection areas (AR1) and the fourth reflection areas (AR4) are opposed to each other, and the second reflection areas (AR2) and the third reflection areas (AR3) are opposed to each other.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: February 12, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Patent number: 8358959
    Abstract: A fixing device includes a first driving system connected to a fixing roller and a separation roller and a second driving system connected to a pressing roller pressed against the fixing roller and the separation roller via a fixing belt. In the first driving system, a first transmission transmits a first driving force generated by a first motor to the fixing roller and the separation roller, and includes a first one-way clutch via which the first driving force is transmitted to the fixing roller. In the second driving system, a second transmission transmits a second driving force generated by a second motor to the pressing roller. When a circumferential velocity of the pressing roller is greater than a circumferential velocity of the fixing roller, the first one-way clutch idles to rotate the fixing roller in accordance with rotation of the pressing roller.
    Type: Grant
    Filed: March 1, 2010
    Date of Patent: January 22, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Masamichi Yamada, Takahiro Yoshikawa
  • Publication number: 20120293980
    Abstract: Provided is a light-emitting unit wherein the directivity of light to be emitted can be lowered while the increase of the number of members thereof is suppressed and the increase of the size thereof is suppressed. An LED package (light-emitting unit) (20) is provided with a base material (23) which includes an element mounting portion (21) and a sidewall portion (22), a light-emitting diode (24) which is disposed on the element mounting portion of the base material, and a sealing resin (25) which covers a light-emitting surface (24a) of the light-emitting diode and has light transmission properties. A recessed portion (26) is formed in a light emission surface (25a) of the sealing resin.
    Type: Application
    Filed: October 26, 2010
    Publication date: November 22, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120293729
    Abstract: It is an object of the present invention to achieve cost reduction or the like in a lighting device. A backlight unit 12 according to the present invention includes: LEDs 17 as a plurality of light sources; at least two LED boards 18 on which the LEDs 17 are mounted; a chassis 14 in which the at least two LED boards 18 are housed; and a connecting and retaining member 22. The at least two LED boards 18 include ones arranged adjacent to each other. The adjacent LED boards 18 are electrically connected to each other and retained on the chassis 14 by the connecting and retaining member 22.
    Type: Application
    Filed: January 11, 2011
    Publication date: November 22, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120293727
    Abstract: A lighting device maintains an optical design and absorbs expansion of a light guide plate with a simple structure if the light guide plate expands toward a light source side. A backlight unit 24 includes an LED board 30; an LED light sources 28 arranged on the LED board 30; a light guide plate 20 having a flat plate shape and including light entrance surfaces 20a1 and 20a2 on side surfaces that are provided on opposite sides, the light entrance surfaces 20a1 and 20a2 being arranged to face the LED light sources 28 of the LED board 30; and spacer members 25a (25b) regulating a distance W1 between the LED board 30 and the light guide plate 20. Each spacer member 25a (25b) has a Young's modulus smaller than that of the light guide plate 20. Each spacer member 25a (25b) regulates the distance W1 between the LED light sources 28 and the light guide plate 20 and absorbs the expansion of the light guide plate 20.
    Type: Application
    Filed: December 17, 2010
    Publication date: November 22, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120281148
    Abstract: In a backlight unit, expansion of a light guide plate and thermal deformation of a light source board may occur. It is an object of the present invention to maintain optical design of the backlight unit with absorbing the expansion of the light guide plate. The backlight unit 24 includes a LED board 30, at least one LED 28 mounted on the LED board 30, a light guide plate 20 having a light entrance surface 20a facing the LED 28, a backlight chassis 22, a spacer member 25 arranged on the LED board 30, and an elastic member 19 arranged between the LED board 30 and the backlight chassis 22. The backlight chassis 22 houses the LED board 30, the LED 28, and the light guide plate 20. The spacer member 25 is configured to restrict a distance W1 between the LED board 30 and the light guide plate 20. The elastic member 19 has Young's modulus smaller than the spacer member 25.
    Type: Application
    Filed: December 17, 2010
    Publication date: November 8, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Patent number: 8300179
    Abstract: A fluorescent tube 30 of the present invention includes a glass tube 31 and electrodes 32 opposed to each other on both end portions 31a of the glass tube 31, characterized in that the electrode 32 has a closed-end hollow shape opened on the opposite side from the end portion 31a of the glass tube 31, and the electrode 32 constituting the closed-end hollow shape has an inner surface 35 configured to be tapered toward the end portion 31a of the glass tube 31. With this configuration, it is possible to contain accelerated electrons not only in the bottom face 33 of the electrode 32 but also in the inner surface 35 of the electrode 32, thereby suppressing sputtering. Consequently, it is possible to increase the life of the fluorescent tube 30.
    Type: Grant
    Filed: May 2, 2008
    Date of Patent: October 30, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Patent number: 8279368
    Abstract: A lighting device 12 for a display device of the present invention includes linear light sources 17 arranged in parallel, connectors 21 for feeding power to the linear light sources 17 and a chassis 14 for housing the linear light sources 17. The chassis 14 has fixing holes 30 for fixing the connectors 21. Each of the fixing holes 30 is formed in a longitudinal shape with its longitudinal direction along the parallel direction of the linear light sources 17. Each of the connectors 21 has a stopper 25 to be fitted in the chassis 14. When the stopper 25 is fitted in the fixing hole 30, the connector 21 is positioned and fitted in the fixing hole 30. The connectors 21 are fixable in a plurality of locations along the longitudinal direction of the fixing hole 30.
    Type: Grant
    Filed: May 2, 2008
    Date of Patent: October 2, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Patent number: 8223292
    Abstract: A lighting device 12 in accordance with the present invention is for use with a display apparatus. The lighting device 12 includes a light source 17, a plate shaped chassis 14 that covers the light source 17, and an inverter board 30 attached to the chassis 14. The lighting device 12 is characterized in that, accompanying slide of the inverter board 30 in a direction parallel to the chassis, the inverter board 30 is attached and detached.
    Type: Grant
    Filed: January 15, 2008
    Date of Patent: July 17, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120120324
    Abstract: A backlight unit 12 according to the present invention includes LEDs 17 as light sources, an LED board 18 mounting the LEDs 17 thereon, a chassis 14 that stores the LED board 18 therein and includes an attachment hole 14e, a body portion 24 that sandwiches the LED board 18 between the body portion 24 and the chassis 14 and holds the LED board 18, and a board holding member 20 including an attachment portion 25 that is protruded from the body portion 24 toward the chassis 14 to be inserted into the attachment hole 14e, and the board holding member 20 is configured to be rotatable along a plate surface of the chassis 14 between a holding position at which the attachment portion 25 overlaps with an edge of the attachment hole 14e in a plan view and sandwiches the edge of the attachment hole 14e between the attachment portion 25 and the body portion 24 and a non-holding position at which the attachment portion 25 does not overlap with the edge of the attachment hole 14e in a plan view and attaching and detaching
    Type: Application
    Filed: June 15, 2010
    Publication date: May 17, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Patent number: 8170461
    Abstract: An image forming apparatus includes an image carrying member, a transfer unit, a pre-heating unit, a fixing unit, a first temperature sensor, and a first heat controller. The image carrying member carries a toner image. The transfer unit transfers the toner image carried on the image carrying member to a recording medium transported to a transfer position. The pre-heating unit selectively heats the recording medium before the recording medium is transported to the transfer position. The fixing unit fixes the toner image on the recording medium. The first temperature sensor detects temperature of the recording medium as the recording medium passes through the pre-heating unit. The first heat controller changes an amount of heat energy to be applied to the recording medium per unit area of the recording medium by the pre-heating unit. The first heat controller is controlled based on a detection result of the first temperature sensor.
    Type: Grant
    Filed: July 7, 2009
    Date of Patent: May 1, 2012
    Assignee: Ricoh Company, Limited
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120092588
    Abstract: A holder (11) fixes a mounting board (21) on a backlight chassis (41), while at least covering the edge (21S) of the mounting board (21) on the backlight chassis (41), said edge being in the short side direction of the mounting board.
    Type: Application
    Filed: March 29, 2010
    Publication date: April 19, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120086884
    Abstract: The present invention provides an art of properly fixing a light source board without using any screw. A backlight unit 12 according to the present invention includes an LED board 18 with an LED 17 as a light source, a chassis 14, an optical member 15, and a supporting member 20. The chassis 14 stores the LED board 18 therein and has an opening 14b through which light from the LED 17 exits. The optical member 15 is arranged so as to face the LED board 18 and to cover the opening 14b. The supporting member 20 supports the optical member 15 from the side of the LED board 18. The supporting member 20 is fixed to the chassis 14 such that the LED board 18 is sandwiched between the supporting member 20 and the chassis 14.
    Type: Application
    Filed: April 6, 2010
    Publication date: April 12, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20120013824
    Abstract: A backlight unit including holding members capable of preventing occurrence of a noise caused when the members are brought into contact with an optical member such as a diffusion plate. A backlight unit (4) includes a chassis (14) including a surface (14a) housing light sources (12), an optical member (11) having a flat plate shape and disposed above the light sources, and members (25) holding the optical member and attached to the housing surface, wherein each of the holding members includes a portion (25a) holding the optical member, and paired leg portions (25b and 25c) extending from the holding portion, elastically deformable in a direction in which the leg portions approach/leave each other and including paired foot portions (25d) disposed at lower ends of the leg portions, at least one of the paired foot portions being placed in a manner slidable on the housing surface in the approaching/leaving direction.
    Type: Application
    Filed: March 31, 2010
    Publication date: January 19, 2012
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa