Patents by Inventor Nobuo Sakuma

Nobuo Sakuma 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: 20120140097
    Abstract: An image capturing apparatus includes an imaging lens, an image pickup device, and a correcting circuit. The imaging lens is configured to focus light from an object to form an image. The image pickup device is configured to pick up the image formed by the imaging lens. The correcting circuit is configured to execute computations for correcting image degradation of the image caused by the imaging lens. The imaging lens is also a single lens having a finite gain of optical transfer function and exhibiting a minute difference in the gain between different angles of view of the imaging lens.
    Type: Application
    Filed: April 27, 2011
    Publication date: June 7, 2012
    Inventors: Nobuhiro Morita, Yuji Yamanaka, Nobuo Sakuma
  • Patent number: 7938545
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: May 10, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7922341
    Abstract: In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: October 20, 2009
    Date of Patent: April 12, 2011
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20110038039
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Application
    Filed: October 21, 2010
    Publication date: February 17, 2011
    Inventors: Atsushi TAKAURA, Kazuhiro FUJITA, Nobuo SAKUMA
  • Patent number: 7705868
    Abstract: A light emitting array including at least a plurality of light emitting elements, each of which is provided thereon with a microlens in one-to-one correspondence. Light emitting portions of the light emitting element are provided having the shape of a rectangle and formed so as to satisfy the relational expression, Lmin?D?P, where Lmin is the length of the shorter side of the rectangle, P an alignment pitch of the light emitting elements, and D the diameter of microlens. In addition, light emitting elements are formed in line on a transparent thin film layer to satisfy the relationship, T1?2·D2, where T1 is the thickness of the transparent thin film layer and D2 the diameter of each microlens. The light emitting array may suitably be included in the light source unit which is then incorporated into image forming apparatuses for forming mono-color or multiple-color images.
    Type: Grant
    Filed: July 15, 2004
    Date of Patent: April 27, 2010
    Assignee: Ricoh Company, Ltd.
    Inventors: Koji Masuda, Nobuo Sakuma, Masahiro Ito
  • Publication number: 20100039625
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Application
    Filed: October 20, 2009
    Publication date: February 18, 2010
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7637621
    Abstract: A projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 29, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7637618
    Abstract: A projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 29, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7631975
    Abstract: A projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: December 15, 2009
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20090021703
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Application
    Filed: September 19, 2008
    Publication date: January 22, 2009
    Inventors: Atsushi TAKAURA, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20090015910
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Application
    Filed: September 19, 2008
    Publication date: January 15, 2009
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20080304019
    Abstract: A projection optical system for use in an image projection apparatus illuminating a lightbulb forming an image in accordance with a modulating signal with illumination light from a light source is disclosed. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the lightbulb. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the lightbulb is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Application
    Filed: March 26, 2008
    Publication date: December 11, 2008
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7441908
    Abstract: A projection optical system for use in an image projection apparatus illuminating a light valve forming an image in accordance with a modulating signal with illumination light from a light source. The projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the light valve. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the light valve is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: February 2, 2006
    Date of Patent: October 28, 2008
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20070285553
    Abstract: An image capturing apparatus includes an imaging lens, an image pickup device, and a correcting circuit. The imaging lens is configured to focus light from an object to form an image. The image pickup device is configured to pick up the image formed by the imaging lens. The correcting circuit is configured to execute computations for correcting image degradation of the image caused by the imaging lens. The imaging lens is also a single lens having a finite gain of optical transfer function and exhibiting a minute difference in the gain between different angles of view of the imaging lens.
    Type: Application
    Filed: May 14, 2007
    Publication date: December 13, 2007
    Inventors: Nobuhiro Morita, Yuji Yamanaka, Nobuo Sakuma
  • Publication number: 20060126032
    Abstract: A projection optical system guiding and projecting a light beam from a projected object surface onto a projection surface in an upstream-downstream direction through a transmission dioptric system and a reflection dioptric system of one or two reflecting mirrors. An intermediate image surface of the projected object surface is positioned closer to the reflection dioptric system than to the transmission dioptric system, and an intermediate image on the intermediate image surface is formed as the final image on the projection surface via the reflecting mirrors, which include at least one anamorphic polynomial free-formed surface having different vertical and lateral powers. A light beam from the reflection dioptric system to the projection surface is guided at an angle to a normal of the projection surface and the transmission dioptric system is decentered with respect to a normal of the projected object surface, the transmission refractive elements prevented from being decentered with respect to each other.
    Type: Application
    Filed: February 2, 2006
    Publication date: June 15, 2006
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: 7048388
    Abstract: A projection optical system guiding and projecting a light beam from a projected object surface onto a projection surface in an upstream-downstream direction through a transmission dioptric system and a reflection dioptric system. An intermediate image surface of the projected object surface is positioned closer to the reflection dioptric system than to the transmission dioptric system, and an intermediate image on the intermediate image surface is formed as the final image on the projection surface via the reflecting mirrors, which include at least one anamorphic polynomial free-formed surface having different vertical and lateral powers. A light beam from the reflection dioptric system to the projection surface is guided at an angle to a normal of the projection surface and the transmission dioptric system is decentered with respect to a normal of the projected object surface, the transmission refractive elements prevented from being decentered with respect to each other.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: May 23, 2006
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Publication number: 20050067944
    Abstract: A light emitting array including at least a plurality of light emitting elements, each of which is provided thereon with a microlens in one-to-one correspondence. Light emitting portions of the light emitting element are provided having the shape of a rectangle and formed so as to satisfy the relational expression, Lmin?D?P, where Lmin is the length of the shorter side of the rectangle, P an alignment pitch of the light emitting elements, and D the diameter of microlens. In addition, light emitting elements are formed in line on a transparent thin film layer to satisfy the relationship, T1?2·D2, where T1 is the thickness of the transparent thin film layer and D2 the diameter of each microlens. The light emitting array may suitably be included in the light source unit which is then incorporated into image forming apparatuses for forming mono-color or multiple-color images.
    Type: Application
    Filed: July 15, 2004
    Publication date: March 31, 2005
    Applicant: RICOH CO., LTD.
    Inventors: Koji Masuda, Nobuo Sakuma, Masahiro Ito
  • Patent number: RE45258
    Abstract: In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: April 11, 2013
    Date of Patent: November 25, 2014
    Assignee: Ricoh Company, Ltd.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: RE45728
    Abstract: In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: October 6, 2015
    Assignee: RICOH COMPANY, LTD.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma
  • Patent number: RE48309
    Abstract: In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.
    Type: Grant
    Filed: March 17, 2017
    Date of Patent: November 17, 2020
    Assignee: RICOH COMPANY, LTD.
    Inventors: Atsushi Takaura, Kazuhiro Fujita, Nobuo Sakuma