Patents by Inventor Akihiko Obama

Akihiko Obama 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: 20240151952
    Abstract: A variable magnification optical system has, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; an aperture stop; a third lens group having positive refractive power; and a rear lens group. Upon zooming from a wide-angle end state to a telephoto end state, at least the rear lens group is moved toward the object side, and distances between the lens groups are varied. Upon focusing from an infinitely distant object to a closely distant object, the third lens group is moved along the optical axis. At least a portion of the rear lens group constitutes a vibration reduction lens group having negative refractive power and moveable perpendicular to the optical axis. An optical apparatus and a method of manufacture are also provided.
    Type: Application
    Filed: January 15, 2024
    Publication date: May 9, 2024
    Inventors: Akihiko OBAMA, Masashi YAMASHITA
  • Patent number: 11892610
    Abstract: A variable magnification optical system has, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; an aperture stop; a third lens group having positive refractive power; and a rear lens group. Upon zooming from a wide-angle end state to a telephoto end state, at least the rear lens group is moved toward the object side, and distances between the lens groups are varied. Upon focusing from an infinitely distant object to a closely distant object, the third lens group is moved along the optical axis. At least a portion of the rear lens group constitutes a vibration reduction lens group having negative refractive power and moveable perpendicular to the optical axis. An optical apparatus and a method of manufacture are also provided.
    Type: Grant
    Filed: July 22, 2020
    Date of Patent: February 6, 2024
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Masashi Yamashita
  • Publication number: 20230324657
    Abstract: A variable magnification optical system includes, in order from an object side, a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group and a distance between the second lens group and the third lens group being varied. The variable magnification optical system further includes a V lens group GV having negative refractive power and being moved to have a component in a direction perpendicular to the optical axis, and an F lens group GF having positive refractive power and being moved along the optical axis upon focusing from an infinitely distant object to a close object, the V lens group GV being disposed on the more object side than the F lens group GF.
    Type: Application
    Filed: June 12, 2023
    Publication date: October 12, 2023
    Inventors: Tomoyuki SASHIMA, Akihiko OBAMA
  • Patent number: 11714268
    Abstract: A variable magnification optical system includes, in order from an object side, a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group and a distance between the second lens group and the third lens group being varied. The variable magnification optical system further includes a V lens group GV having negative refractive power and being moved to have a component in a direction perpendicular to the optical axis, and an F lens group GF having positive refractive power and being moved along the optical axis upon focusing from an infinitely distant object to a close object, the V lens group GV being disposed on the more object side than the F lens group GF.
    Type: Grant
    Filed: March 23, 2022
    Date of Patent: August 1, 2023
    Assignee: Nikon Corporation
    Inventors: Tomoyuki Sashima, Akihiko Obama
  • Patent number: 11653096
    Abstract: A calculation device calculating an amount of movement in an optical axis direction of a focusing lens which adjusts a focal position of an imaging optical system includes: a first input unit to which first information about a deviation between an imaging surface which captures an image by the imaging optical system and the focal position is repeatedly input; a second input unit to which second information about a shake of the imaging optical system in the optical axis direction is repeatedly input at intervals shorter than those of the first information; and a calculation unit which calculates the amount of movement on the basis of at least one of the first information and the second information, wherein the calculation unit calculates the amount of movement on the basis of the second information between an input of the first information and an input of the next first information.
    Type: Grant
    Filed: October 28, 2019
    Date of Patent: May 16, 2023
    Assignee: NIKON CORPORATION
    Inventors: Satoshi Kazahaya, Yuki Kinouchi, Akihiko Obama, Satoru Shibata
  • Patent number: 11579421
    Abstract: A zoom lens includes, in order from an object side along an optical axis, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. Upon zooming from a wide-angle end state W to a telephoto end state T, a distance between the first lens group G1 and the second lens group G2 increases, and a distance between the second lens group G2 and the third lens group G3 decreases. Given conditions are satisfied. Accordingly, a zoom lens having high optical performance with suppressing variations in aberrations, an optical apparatus equipped therewith, and a method for manufacturing the zoom lens are provided.
    Type: Grant
    Filed: December 15, 2020
    Date of Patent: February 14, 2023
    Assignee: NIKON CORPORATION
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Patent number: 11385446
    Abstract: A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having positive refractive power, a fifth lens group (G5) are arranged in order from an object, and a distance between the first lens group (G1) and the second lens group (G2), a distance between the second lens group (G2) and the third lens group (G3), a distance between the third lens group (G3) and the fourth lens group (G4), and a distance between the fourth lens group (G4) and the fifth lens group (G5) change upon zooming, and a lens group arranged closest to an image is approximately fixed against an image surface (I) upon zooming, and the third lens group (G3) moves along the optical axis upon focusing, and the following expression (1) is satisfied. 0.480<f3/ft<4.
    Type: Grant
    Filed: September 6, 2019
    Date of Patent: July 12, 2022
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Kensuke Uchida
  • Publication number: 20220214529
    Abstract: A variable magnification optical system includes, in order from an object side, a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group and a distance between the second lens group and the third lens group being varied. The variable magnification optical system further includes a V lens group GV having negative refractive power and being moved to have a component in a direction perpendicular to the optical axis, and an F lens group GF having positive refractive power and being moved along the optical axis upon focusing from an infinitely distant object to a close object, the V lens group GV being disposed on the more object side than the F lens group GF.
    Type: Application
    Filed: March 23, 2022
    Publication date: July 7, 2022
    Inventors: Tomoyuki SASHIMA, Akihiko OBAMA
  • Publication number: 20220201215
    Abstract: A calculation device calculating an amount of movement in an optical axis direction of a focusing lens which adjusts a focal position of an imaging optical system includes: a first input unit to which first information about a deviation between an imaging surface which captures an image by the imaging optical system and the focal position is repeatedly input; a second input unit to which second information about a shake of the imaging optical system in the optical axis direction is repeatedly input at intervals shorter than those of the first information; and a calculation unit which calculates the amount of movement on the basis of at least one of the first information and the second information, wherein the calculation unit calculates the amount of movement on the basis of the second information between an input of the first information and an input of the next first information.
    Type: Application
    Filed: October 28, 2019
    Publication date: June 23, 2022
    Applicant: NIKON CORPORATION
    Inventors: Satoshi KAZAHAYA, Yuki KINOUCHI, Akihiko OBAMA, Satoru SHIBATA
  • Patent number: 11294155
    Abstract: A variable magnification optical system includes, in order from an object side, a first lens group having positive refractive power; a second lens group having negative refractive power; and a third lens group having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group and a distance between the second lens group and the third lens group being varied. The variable magnification optical system further includes a V lens group GV having negative refractive power and being moved to have a component in a direction perpendicular to the optical axis, and an F lens group GF having positive refractive power and being moved along the optical axis upon focusing from an infinitely distant object to a close object, the V lens group GV being disposed on the more object side than the F lens group GF.
    Type: Grant
    Filed: July 17, 2018
    Date of Patent: April 5, 2022
    Assignee: Nikon Corporation
    Inventors: Tomoyuki Sashima, Akihiko Obama
  • Publication number: 20210103133
    Abstract: A zoom lens includes, in order from an object side along an optical axis, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. Upon zooming from a wide-angle end state W to a telephoto end state T, a distance between the first lens group G1 and the second lens group G2 increases, and a distance between the second lens group G2 and the third lens group G3 decreases. Given conditions are satisfied. Accordingly, a zoom lens having high optical performance with suppressing variations in aberrations, an optical apparatus equipped therewith, and a method for manufacturing the zoom lens are provided.
    Type: Application
    Filed: December 15, 2020
    Publication date: April 8, 2021
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Patent number: 10948700
    Abstract: Comprising, in order from an object side: a first lens group G1 having positive refractive power; a second lens group G2 having negative refractive power; an aperture stop S; a third lens group G3 having positive refractive power; and a fourth lens group G4 having positive refractive power; upon zooming from a wide-angle end state to a telephoto end state, the distance between the first lens group G1 and the second lens group G2, the distance between the second lens group G2 and the aperture stop S, the distance between the aperture stop S and the third lens group G3, and the distance between the third lens group G3 and the fourth lens group G4 being varied, and the distance between the aperture stop S and the fourth lens group G4 being constant; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which is compact in size and has a high variable magnification ratio and high optical performance, an optical apparatus, and a method for manufacturi
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: March 16, 2021
    Assignee: Nikon Corporation
    Inventor: Akihiko Obama
  • Patent number: 10895721
    Abstract: A zoom lens includes, in order from an object side along an optical axis, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. Upon zooming from a wide-angle end state W to a telephoto end state T, a distance between the first lens group G1 and the second lens group G2 increases, and a distance between the second lens group G2 and the third lens group G3 decreases. Given conditions are satisfied. Accordingly, a zoom lens having high optical performance with suppressing variations in aberrations, an optical apparatus equipped therewith, and a method for manufacturing the zoom lens are provided.
    Type: Grant
    Filed: December 31, 2018
    Date of Patent: January 19, 2021
    Assignee: NIKON CORPORATION
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Patent number: 10831007
    Abstract: A variable magnification optical system has, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; an aperture stop; a third lens group having positive refractive power; and a rear lens group. Upon zooming from a wide-angle end state to a telephoto end state, at least the rear lens group is moved toward the object side, and distances between the lens groups are varied. Upon focusing from an infinitely distant object to a closely distant object, the third lens group is moved along the optical axis. At least a portion of the rear lens group constitutes a vibration reduction lens group having negative refractive power and moveable perpendicular to the optical axis. An optical apparatus and a method of manufacture are also provided.
    Type: Grant
    Filed: May 16, 2018
    Date of Patent: November 10, 2020
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Masashi Yamashita
  • Patent number: 10831005
    Abstract: A variable magnification optical system includes: a positive first lens group; a negative lens group closer to an image than the first lens group; a positive lens group closer to the image than the negative lens group and including at least one lens closer to the image than an aperture stop; and a focusing group between the negative lens group and the positive lens group. When varying magnification, the first lens group moves with respect to an image plane, and distances between the first lens group and the negative lens group and between the negative lens group and the positive lens group are changed. When focusing, a distance between the focusing group and a lens facing an object-side of the focusing group is changed, and a distance between the focusing group and a lens facing an image-side of the focusing group is changed. Predetermined conditional expressions are satisfied.
    Type: Grant
    Filed: December 25, 2015
    Date of Patent: November 10, 2020
    Assignee: Nikon Corporation
    Inventors: Kensuke Uchida, Akihiko Obama, Hiroshi Yamamoto, Taku Matsuo
  • Publication number: 20200348497
    Abstract: A variable magnification optical system has, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; an aperture stop; a third lens group having positive refractive power; and a rear lens group. Upon zooming from a wide-angle end state to a telephoto end state, at least the rear lens group is moved toward the object side, and distances between the lens groups are varied. Upon focusing from an infinitely distant object to a closely distant object, the third lens group is moved along the optical axis. At least a portion of the rear lens group constitutes a vibration reduction lens group having negative refractive power and moveable perpendicular to the optical axis. An optical apparatus and a method of manufacture are also provided.
    Type: Application
    Filed: July 22, 2020
    Publication date: November 5, 2020
    Inventors: Akihiko OBAMA, Masashi YAMASHITA
  • Publication number: 20190391374
    Abstract: A first lens group (G1) having positive refractive power, a second lens group (G2) having negative refractive power, a third lens group (G3) having positive refractive power, a fourth lens group (G4) having positive refractive power, a fifth lens group (G5) are arranged in order from an object, and a distance between the first lens group (G1) and the second lens group (G2), a distance between the second lens group (G2) and the third lens group (G3), a distance between the third lens group (G3) and the fourth lens group (G4), and a distance between the fourth lens group (G4) and the fifth lens group (G5) change upon zooming, and a lens group arranged closest to an image is approximately fixed against an image surface (I) upon zooming, and the third lens group (G3) moves along the optical axis upon focusing, and the following expression (1) is satisfied. 0.480<f3/ft<4.
    Type: Application
    Filed: September 6, 2019
    Publication date: December 26, 2019
    Inventors: Akihiko OBAMA, Kensuke UCHIDA
  • Patent number: 10466453
    Abstract: An optical system comprises a first lens group G1 disposed in a most object side and having positive refractive power, a stop member ST disposed at an image side of the first lens group G1, and a second lens group G2 disposed at an image side of the stop member ST. A predetermined conditional expression is satisfied, whereby light beyond the maximum angle of view collected on the focal point position of a most object side lens group having positive refractive power is reduced, so that heat generated by a member in the vicinity of the focal point position is reduced.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: November 5, 2019
    Assignee: Nikon Corporation
    Inventors: Hiroyuki Ishigami, Kunihiko Shimizu, Akihiko Obama, Takuji Hamasaki
  • Patent number: 10451858
    Abstract: A first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having positive refractive power, a fifth lens group are arranged in order from an object. Respective distances between the first and second lens groups, the second and third lens groups, the third and fourth lens groups, and the fourth lens and fifth lens groups change upon zooming, and a lens group arranged closest to an image is approximately fixed relative to an image surface upon zooming. The third lens group moves along the optical axis upon focusing, and the following expression (1) is satisfied: 0.480<f3/ft<4.000??(1) where ft denotes a focal length of the zoom optical system in a telephoto end state, and f3 denotes a focal length of the third lens group.
    Type: Grant
    Filed: October 20, 2016
    Date of Patent: October 22, 2019
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Kensuke Uchida
  • Patent number: 10317654
    Abstract: A variable magnification optical system includes: a first lens group having positive refractive power and arranged closest to an object; a negative lens group having negative refractive power; a positive lens group which has positive refractive power, which includes at least one lens that moves integrally with an aperture stop, and which is arranged closer to an image than the negative lens group; and a focusing group arranged between the negative lens group and the positive lens group. When varying magnification, distances between the first lens group and the negative lens group and between the negative lens group and the positive lens group are changed. When focusing, distances between the focusing group and a lens facing an object-side of the focusing group and between the focusing group and a lens facing an image-side of the focusing group are changed. A predetermined conditional expression is satisfied.
    Type: Grant
    Filed: December 25, 2015
    Date of Patent: June 11, 2019
    Assignee: Nikon Corporation
    Inventors: Kensuke Uchida, Akihiko Obama, Norikazu Yokoi, Hiroshi Yamamoto, Taku Matsuo