Patents by Inventor Nobutaka Minefuji

Nobutaka Minefuji 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: 20220206252
    Abstract: A projection system includes a first optical system and a second optical system. The second optical system includes a first lens group disposed on an enlargement side of an intersection position where a chief ray of an off-axis beam having a maximum angle of view intersects with an optical axis of the projection system in the second optical system, a second lens group disposed on the reduction side of the intersection position and having negative power, and a third lens group disposed on the reduction side of the second lens group and having positive power. The second lens group includes a first lens having positive power, a second lens disposed on the reduction side of the first lens and having positive power, and a third lens disposed on the reduction side of the second lens and having negative power. The third lens group includes two lenses each having positive power.
    Type: Application
    Filed: December 23, 2021
    Publication date: June 30, 2022
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Yasuyuki KIYAMA, Hitoshi HIRANO, Nobutaka MINEFUJI, Koji SHIOKAWA
  • Patent number: 11061308
    Abstract: A projection optical system includes a first lens group having negative power and a second and third lens group having positive power, and a first optical path deflector disposed between two lens groups. The first lens group includes three negative lenses. The second lens group includes at least one positive lens. The third lens group includes a plurality of positive lenses. The three negative lenses of the first lens group are each a single lens. The third lens group includes a jointed lens including at least one of the plurality of positive lenses. f is a focal length of the entire project in optical system, d is a length between two lens groups where the first optical path defector is disposed, Dst is a distortion aberration at a reduction-side maximum image height, and the projection optical system satisfies Conditional Expressions (1) and (2) below: 0.4<d/f<12.0??(1) ?45%<Dst<?10%??(2).
    Type: Grant
    Filed: June 26, 2020
    Date of Patent: July 13, 2021
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Publication number: 20200409246
    Abstract: A projection optical system includes a first lens group having negative power and a second and third lens group having positive power, and a first optical path deflector disposed between two lens groups. The first lens group includes three negative lenses. The second lens group includes at least one positive lens. The third lens group includes a plurality of positive lenses. The three negative lenses of the first lens group are each a single lens. The third lens group includes a jointed lens including at least one of the plurality of positive lenses. f is a focal length of the entire project in optical system, d is a length between two lens groups where the first optical path defector is disposed, Dst is a distortion aberration at a reduction-side maximum image height, and the projection optical system satisfies Conditional Expressions (1) and (2) below: 0.4<d/f<12.0??(1) ?45%<Dst<?10%??(2).
    Type: Application
    Filed: June 26, 2020
    Publication date: December 31, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Publication number: 20200409126
    Abstract: A projection optical system includes a first lens group having negative power, a second lens group having positive power and disposed at a reduction side of the first lens group, and a third lens group having positive power and disposed at the reduction side of the second lens group. The first lens group includes at least three negative lenses. The second lens group includes at least one positive lens. The third lens group includes a plurality of positive lenses. The at least three negative lenses of the first lens group are each a single lens. The third lens group includes a jointed lens including at least one of the plurality of positive lenses. NA is a reduction-side numerical aperture, Dst is a distortion aberration at a reduction-side maximum image height, and the projection optical system satisfies Conditional Expressions (1) and (2), 0.2<NA??(1) ?45%<Dst<?10%??(2).
    Type: Application
    Filed: June 26, 2020
    Publication date: December 31, 2020
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Patent number: 10824059
    Abstract: A first optical group that forms an intermediate image and a second optical group that enlarges and projects the intermediate image formed by the first optical group satisfy a variety of conditions. Therefore, the overall length of the entire lens system of the projection system is reduced in a linear arrangement, or the distance between the first optical group and the second optical group is increased and an optical path deflector that deflects the optical path is disposed at the middle of the optical path between the first and second optical groups to fold the optical path.
    Type: Grant
    Filed: March 18, 2019
    Date of Patent: November 3, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Patent number: 10802389
    Abstract: A first optical group that forms an intermediate image and a second optical group that enlarges and projects the intermediate image formed by the first optical group satisfy a variety of conditions. Therefore, first of all, in a case where a projection system is incorporated in a projector, an ultrawide field angle that allows enlargement and projection of an image at a half angle of view of 50° or greater is achieved. Further, an optical path deflection system including two optical path deflectors is disposed between the first optical group and the second optical group to allow the optical path to be folded with deterioration in performance of the projection system suppressed.
    Type: Grant
    Filed: March 18, 2019
    Date of Patent: October 13, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Patent number: 10539766
    Abstract: A projection optical system includes a first lens unit adapted to make a enlargement-side imaging surface and an intermediate image conjugate with each other, a second lens unit adapted to make the intermediate image and a reduction-side imaging surface conjugate with each other. The first lens unit has positive power, and the second lens unit has negative power. Defining a focal distance of the first lens unit as fU1, a focal distance of the second lens unit as fU2, a total lens length of the first lens unit as LLU1, and a total lens length of the second lens unit as LLU2, the following expression (1) and expression (2) are satisfied: ?0.3<fU1/fU2<?0.005??(1) 0.5<LLU1/LLU2<0.9??(2).
    Type: Grant
    Filed: December 4, 2017
    Date of Patent: January 21, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Koji Shiokawa, Nobutaka Minefuji
  • Patent number: 10534252
    Abstract: A projection optical system and that includes a relatively small number of lenses and are able to cover a wide zooming range and a projector. A 1-2 lens group which is a focus lens group is constituted with a lens which includes a single positive lens having a convex surface to the reduction side, a lens which includes a single negative meniscus lens having a convex surface to an enlargement side, and a lens which includes a single negative lens, and the 1-2 lens group is moved at the time of focusing accompanying magnification change.
    Type: Grant
    Filed: June 10, 2016
    Date of Patent: January 14, 2020
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Patent number: 10466452
    Abstract: A projection optical system capable of performing compact and proximate projection and a projector including the projection optical system. The projection optical system includes a first optical group which is a dioptric system and a second optical group which is a catoptric system. The second optical group includes a first catoptric system to a third catoptric system that have a first reflection surface with a concave surface shape, a second reflection surface with a curved surface shape, and a third reflection surface with a convex surface shape. The first catoptric system to the third catoptric system satisfy Conditional Expression (1) for focal distances. Image light emitted from the first optical group is reflected by the second optical group to be projected to a projection surface.
    Type: Grant
    Filed: August 19, 2016
    Date of Patent: November 5, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Publication number: 20190331901
    Abstract: A first optical group that forms an intermediate image and a second optical group that enlarges and projects the intermediate image formed by the first optical group satisfy a variety of conditions. Therefore, first of all, in a case where a projection system is incorporated in a projector, an ultrawide field angle that allows enlargement and projection of an image at a half angle of view of 50° or greater is achieved. Further, an optical path deflection system including two optical path deflectors is disposed between the first optical group and the second optical group to allow the optical path to be folded with deterioration in performance of the projection system suppressed.
    Type: Application
    Filed: March 18, 2019
    Publication date: October 31, 2019
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Publication number: 20190285972
    Abstract: A first optical group that forms an intermediate image and a second optical group that enlarges and projects the intermediate image formed by the first optical group satisfy a variety of conditions. Therefore, the overall length of the entire lens system of the projection system is reduced in a linear arrangement, or the distance between the first optical group and the second optical group is increased and an optical path deflector that deflects the optical path is disposed at the middle of the optical path between the first and second optical groups to fold the optical path.
    Type: Application
    Filed: March 18, 2019
    Publication date: September 19, 2019
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Patent number: 10203487
    Abstract: An imaging lens system (imaging lens) having a focal length f is formed of a first lens group formed of three negative lenses and a single positive lens or a cemented lens and a second lens group having a positive focal length with the first lens group and the second lens group sequentially arranged from the enlargement side and employs the stereographic projection method that satisfies a condition of y=a·f·tan(?/2) (?: 1.8???2.2). The thus configured imaging lens system readily allows distortion to be reduced at each image height y and the degree of compression to be also reduced for sufficient resolution at the periphery.
    Type: Grant
    Filed: November 8, 2017
    Date of Patent: February 12, 2019
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Patent number: 10156708
    Abstract: First through third lens groups constituting a projection zoom lens can be configured as a zoom lens of the type in which the first and second lens groups, for example, are moved when zooming, and the first lens group, for example, is moved when focusing. Further, by fulfilling the conditional formula (1), it is possible to achieve that the back focus is prevented from becoming too short, and the back focus is prevented from becoming too long while ensuring the sufficient space on the reduction side, and the lens diameter on the reduction side is prevented from becoming too large in the case of adopting a roughly telecentric configuration on the reduction side.
    Type: Grant
    Filed: October 6, 2017
    Date of Patent: December 18, 2018
    Assignee: SEIKO EPSON CORPORATION
    Inventor: Nobutaka Minefuji
  • Publication number: 20180246302
    Abstract: A projection optical system capable of performing compact and proximate projection and a projector including the projection optical system. The projection optical system includes a first optical group which is a dioptric system and a second optical group which is a catoptric system. The second optical group includes a first catoptric system to a third catoptric system that have a first reflection surface with a concave surface shape, a second reflection surface with a curved surface shape, and a third reflection surface with a convex surface shape. The first catoptric system to the third catoptric system satisfy Conditional Expression (1) for focal distances. Image light emitted from the first optical group is reflected by the second optical group to be projected to a projection surface.
    Type: Application
    Filed: August 19, 2016
    Publication date: August 30, 2018
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Publication number: 20180173088
    Abstract: A projection optical system and that includes a relatively small number of lenses and are able to cover a wide zooming range and a projector. A 1-2 lens group which is a focus lens group is constituted with a lens which includes a single positive lens having a convex surface to the reduction side, a lens which includes a single negative meniscus lens having a convex surface to an enlargement side, and a lens which includes a single negative lens, and the 1-2 lens group is moved at the time of focusing accompanying magnification change.
    Type: Application
    Filed: June 10, 2016
    Publication date: June 21, 2018
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Publication number: 20180164554
    Abstract: A projection optical system includes a first lens unit adapted to make a enlargement-side imaging surface and an intermediate image conjugate with each other, a second lens unit adapted to make the intermediate image and a reduction-side imaging surface conjugate with each other. The first lens unit has positive power, and the second lens unit has negative power. Defining a focal distance of the first lens unit as fU1, a focal distance of the second lens unit as fU2, a total lens length of the first lens unit as LLU1, and a total lens length of the second lens unit as LLU2, the following expression (1) and expression (2) are satisfied. ?0.3<fU1/fU2<?0.005 ??(1) 0.5<LLU1/LLU2<0.
    Type: Application
    Filed: December 4, 2017
    Publication date: June 14, 2018
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Koji SHIOKAWA, Nobutaka Minefuji
  • Publication number: 20180143411
    Abstract: An imaging lens system (imaging lens) having a focal length f is formed of a first lens group formed of three negative lenses and a single positive lens or a cemented lens and a second lens group having a positive focal length with the first lens group and the second lens group sequentially arranged from the enlargement side and employs the stereographic projection method that satisfies a condition of y=a·f·tan(?/2) (?: 1.8???2.2). The thus configured imaging lens system readily allows distortion to be reduced at each image height y and the degree of compression to be also reduced for sufficient resolution at the periphery.
    Type: Application
    Filed: November 8, 2017
    Publication date: May 24, 2018
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Publication number: 20180113286
    Abstract: First through third lens groups constituting a projection zoom lens can be configured as a zoom lens of the type in which the first and second lens groups, for example, are moved when zooming, and the first lens group, for example, is moved when focusing. Further, by fulfilling the conditional formula (1), it is possible to achieve that the back focus is prevented from becoming too short, and the back focus is prevented from becoming too long while ensuring the sufficient space on the reduction side, and the lens diameter on the reduction side is prevented from becoming too large in the case of adopting a roughly telecentric configuration on the reduction side.
    Type: Application
    Filed: October 6, 2017
    Publication date: April 26, 2018
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Nobutaka MINEFUJI
  • Patent number: 9885943
    Abstract: A projector used a projection lens to enlarge and project image light generated by image generator. When it is assumed that the on-optical-axis position of a lens surface where the maximum of light ray passage ranges (effective diameter) is minimized in the projection lens is a minimum diameter position, a stop is provided on a lens shifted from the minimum diameter position toward the light exiting side. The lens on which the stop is provided is a lens (for example, fourth lens closest to minimum diameter position) that satisfies 0.8?1??2??1, where ?1 represents the light flux diameter on a surface where the on-axis light flux diameter is maximized, and ?2 is the diameter of the stop.
    Type: Grant
    Filed: June 2, 2017
    Date of Patent: February 6, 2018
    Assignee: SEIKO EPSON CORPORATION
    Inventors: Naoto Takehana, Nobutaka Minefuji
  • Publication number: 20170357147
    Abstract: A projector used a projection lens to enlarge and project image light generated by image generator. When it is assumed that the on-optical-axis position of a lens surface where the maximum of light ray passage ranges (effective diameter) is minimized in the projection lens is a minimum diameter position, a stop is provided on a lens shifted from the minimum diameter position toward the light exiting side. The lens on which the stop is provided is a lens (for example, fourth lens closest to minimum diameter position) that satisfies 0.8?1??2??1, where ?1 represents the light flux diameter on a surface where the on-axis light flux diameter is maximized, and ?2 is the diameter of the stop.
    Type: Application
    Filed: June 2, 2017
    Publication date: December 14, 2017
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Naoto TAKEHANA, Nobutaka MINEFUJI