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: 8055174
    Abstract: In a fixing device for fixing a toner image on a recording medium, a fixing roller and a heating roller support a fixing belt. A pressing roller presses against the fixing roller via the fixing belt to form a fixing nip between the fixing belt and the pressing roller. A tension roller presses against the fixing belt to apply tension to the fixing belt. A primary heat source heats the fixing belt, and is disposed along an outer face of the fixing belt opposite the heating roller. A secondary heat source is provided inside the tension roller to supply deficient heat not provided by the primary heat source.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: November 8, 2011
    Assignee: Ricoh Company, Ltd.
    Inventor: Takahiro Yoshikawa
  • Patent number: 8050583
    Abstract: A fixing device, an image forming apparatus using the fixing device, and a temperature control method therefor. The fixing device includes a fixing roller, a heat roller including first and second heat sources, a fixing belt, a pressure roller including a pressure heat source, a first temperature detector, a second temperature detector, and a pressure temperature detector. The heat sources are regularly on and off according to a duty cycle, and at least one of the heat sources is controlled by the duty cycle during paper feed. A wattage of one of the heat sources is added to a wattage of at least one of the other heat sources when the temperature detected by the first or second temperature detector corresponding to the one of the heat sources reaches the set temperature such that a duty ratio of the at least one of the other heat sources is increased.
    Type: Grant
    Filed: August 1, 2008
    Date of Patent: November 1, 2011
    Assignee: Ricoh Company, Limited
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110234917
    Abstract: A light source unit, a lighting device, a display device and a television receiver configured to reduce deterioration of display quality are provided. The light source unit of the present invention includes light guide members 34. Each light guide member 34 includes a light guide portion 34B configured to guide incident light and a light exit portion 34A having a light exit surface 41 through which the incident light guided by the light guide portion 34B exits. The light exit portion 34A of one of the light guide members 34 is placed over the light guide portion 34B of another one of the light guide members 34. A reflection layer 50 is provided on a part of a surface of each light guide member 34 opposite from the light exit surface 41 from the light guide portion 34B to the light exit portion 34A. The reflection layer 50 is configured to reflect incident light to an inside of the other one of the light guide member 34.
    Type: Application
    Filed: November 5, 2009
    Publication date: September 29, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110221977
    Abstract: In a light source unit, a lighting device, a display device and a television receiver, display quality is not deteriorated. A light source unit includes a number of light guide members 27. The light guide members 27 are arranged in a first direction and in a second direction that is substantially perpendicular to the first direction. Each light guide member 27 is formed in a flat shape and includes a light exit portion 27A and a light guide portion 27B. Light entering the light guide member 27 exits from the light exit portion 27A and the light guide portion 27B guides light entering the light guide member 27 to the light exit portion 27A. Extended portions 40 are formed on facing side end portions of the light guide members 27 that are arranged in adjacent to each other in the second direction. Each of the extended portions 40 extends from the corresponding side end portion of the light guide member so as to be fitted to and overlap each other in a front-rear direction.
    Type: Application
    Filed: November 5, 2009
    Publication date: September 15, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110217100
    Abstract: An image forming apparatus includes a gloss applying mode for applying gloss to an image on a sheet and a non-gloss-applying mode. The image forming apparatus includes a fixing device including a fixing member and a pressurizing member that is pressed into contact with the fixing member to form a fixing nip portion in which toner is fixed to the sheet; and a gloss applying device including a first roller including a heating unit and a second roller that is pressed into contact with the first roller to form a gloss applying nip portion in which gloss is applied to the toner. The fixing device and the gloss applying device are provided on a sheet conveying path line. When the sheet is conveyed in the non-gloss-applying mode, nip pressure of the gloss applying nip portion in the gloss applying device is lower than that in the gloss applying mode.
    Type: Application
    Filed: November 12, 2009
    Publication date: September 8, 2011
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110211134
    Abstract: A backlight unit 12 includes an LED 16, a light guide plate 18, an LED board 17 and a clip 23. The light guide plate 18 includes a light entrance surface 34 and a light exit surface 36. The light entrance surface 34 is provided to face the LED 16 and rays of light emitted from the LED 16 enter the light entrance surface 34. The light exit surface 36 is provided parallel to an arrangement direction in which the LED 16 and the light entrance surface 34 are arranged and rays of light exit through the light exit surface 36. The LED 16 and the light guide plate 18 are fixed to the LED board 17. The light guide plate 18 is fixed to the LED board 17 by the clip 23 and the clip is provided in adjacent to the light entrance surface 34 in the arrangement direction in which the LED 16 and the light entrance surface 34 are arranged.
    Type: Application
    Filed: September 7, 2009
    Publication date: September 1, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110205451
    Abstract: The present invention relates to a backlight unit 12 including a plurality of light source units U. Each light source unit U includes at least an LED 16 and a light guide plate 18. The light source units U are arranged along one direction with gaps S between the adjacent light guide plates 18. Light L1 from each LED 16 enters the corresponding light guide plate 18 and exits from a first light exit surface 36A. An optical member 15 is arranged so as to face the first light exit surface 36A. The light L1 exiting from the first light exit surface 36A enters the optical member 15. Each light guide plate 18 has a second light exit surface 36B at one of ends that face the gap S on the optical member 15 side. Light L2 exits from the second light exit surface 36B toward the optical member 15 via the gap S.
    Type: Application
    Filed: September 7, 2009
    Publication date: August 25, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110128450
    Abstract: The present invention provides an illumination device including a plurality of light guides. The illumination device of the present invention can realize improved luminance uniformity. The illumination device of the present invention is a backlight (illumination device) (20) that includes: a plurality of combinations of a light source and a light guide (7) for causing surface emission of light that comes from the light source; and reflecting sheets (reflecting members) (6), each of which faces and covers that surface of corresponding one of the light guides (7) which is an opposing surface of a light emitting surface (7a), each of the reflecting sheets (reflecting members) (6) configured to partially overlap with its adjacent one, in a normal direction of the light emitting surface (7a), over a gap (1) between corresponding two (7, 17) of the light guides which are arranged adjacently to one another so as not to overlap with one another.
    Type: Application
    Filed: September 30, 2009
    Publication date: June 2, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Patent number: 7949290
    Abstract: An image fixing apparatus includes a fixing member, a magnetic flux generator, a heat member, a core, and a magnetic flux adjuster. The fixing member fixes the toner image onto the recording medium. The magnetic flux generator generates a magnetic flux. The heat member has a heat layer which is heated inductively by the magnetic flux generated by the magnetic flux generator and heats the fixing member. The core faces the magnetic flux via the heat member. The magnetic flux adjuster is configured to vary a heating range of the heat member in the width direction. The heat layer has a predetermined Curie point.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: May 24, 2011
    Assignee: Ricoh Company, Limited
    Inventor: Takahiro Yoshikawa
  • Publication number: 20110021854
    Abstract: A process converts ethylbenzene in a C8 aromatic hydrocarbon mixture containing a large amount of non-aromatic hydrocarbons, mainly to benzene, by which the xylene loss is small, the deactivation rate of the catalyst can be reduced, and a high conversion rate to p-xylene can be attained. The process for converting ethylbenzene includes bringing a feedstock containing an alicyclic hydrocarbon(s) in an amount of not less than 1.0% by weight, ethylbenzene and xylene into contact with hydrogen in the presence of a catalyst to convert ethylbenzene mainly to benzene, wherein the catalyst is mainly composed of MFI zeolite and an inorganic oxide(s) and rhenium-supported, and wherein the conversion is carried out at a reaction pressure of not less than 1.0 MPa-G.
    Type: Application
    Filed: March 18, 2009
    Publication date: January 27, 2011
    Applicant: TORAY INDUSTRIES, INC.
    Inventors: Takahiro Yoshikawa, Masatoshi Watanabe, Ryoji Ichioka
  • Publication number: 20110001891
    Abstract: A backlight device 12 includes a chassis 14, a cold-cathode tube 17 that is disposed in the chassis 14, a main body 27 that is mounted on the chassis 14, a lamp clip 18 that is provided in the main body 27 so as to grip the cold-cathode tube 17, and a reflecting sheet 23 that is disposed in the chassis 14. The reflecting sheet has an opening 41 through which the lamp gripping portion 28 is passed, and an inner edge portion of the opening 41 covers an outer edge portion of the main body 27.
    Type: Application
    Filed: February 2, 2009
    Publication date: January 6, 2011
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100321927
    Abstract: The present invention comprises: a main body 27 that is mounted on a chassis 14; a lamp gripping portion 28 that is provided in a main body 27 to be able to grip a cold-cathode tube 17; and mounting portions 30 and 31 that include base portions 30a and 31a projected from the main body 27 toward the side of the chassis 14 and extending portions 30b and 31b projected from the base portions 30a and 31a in the direction along the main body 27, the mounting portions 30 and 31 being slid in the direction along the main body 27 from the state in which the mounting portions 30 and 31 are inserted in mounting holes 32 and 33 provided in the chassis 14, thereby enabling the peripheral edge portions of the mounting holes 32 and 33 to be retained while sandwiched between the extending portions 30b and 31b and the main body 27, wherein a reinforcement portion 44 that continues to at least two of the main body 27 and the base portion 30a and extending portion 30b, which constitute the first mounting portion 30, is formed.
    Type: Application
    Filed: February 2, 2009
    Publication date: December 23, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100309393
    Abstract: An illuminating device (3) provided with a plurality of hot cathode fluorescent tubes (discharge tubes) (20a to 20f) includes: sockets (21a to 21f) to be connected electrically to respective electrode portions (20A) of the plurality of the hot cathode fluorescent tubes (20a to 20f); and a wiring member (22) that is connected electrically to a plurality of the sockets (21a to 21f) so as to integrate wirings (22b1 to 22b12) of the plurality of the hot cathode fluorescent tubes (20a to 20f).
    Type: Application
    Filed: October 1, 2008
    Publication date: December 9, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100296005
    Abstract: A discharge tube 17 of the present invention includes a glass tube 30, a ferrule 40 attached to an end of the glass tube 30, and lead wires 32a and 32b provided at an end of the glass tube 30. The lead wires 32a and 32b are bent and inserted in the ferrule 40 such that they are in contact with the ferrule 40. They can receive external power supply via the ferrule 40. The lead wires 32a and 32b that are non-light-emitting portions of the discharge tube 17 are bent and thus the apparent lengths of the lead wires 32a and 32b can be reduced. The light emitting area of the discharge tube 17 with respect to the whole length is increased.
    Type: Application
    Filed: October 2, 2008
    Publication date: November 25, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100283905
    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: Application
    Filed: December 10, 2008
    Publication date: November 11, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventors: Shuki Yamamoto, Yasumori Kuromizu, Kaori Yamamoto, Takahiro Yoshikawa
  • Publication number: 20100272458
    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: Application
    Filed: April 26, 2010
    Publication date: October 28, 2010
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100246190
    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: Application
    Filed: July 23, 2008
    Publication date: September 30, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100226700
    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: March 1, 2010
    Publication date: September 9, 2010
    Inventors: Masamichi Yamada, Takahiro Yoshikawa
  • Publication number: 20100214512
    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: Application
    Filed: May 2, 2008
    Publication date: August 26, 2010
    Inventor: Takahiro Yoshikawa
  • Publication number: 20100208144
    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: Application
    Filed: May 2, 2008
    Publication date: August 19, 2010
    Applicant: SHARP KABUSHIKI KAISHA
    Inventor: Takahiro Yoshikawa