Patents by Inventor Issei Tanaka

Issei Tanaka 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: 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
  • 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: 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: 10302905
    Abstract: An optical system includes, disposed in sequence along an optical axis starting on an object side: a first lens group having a positive refractive power, which remains fixed relative to an image surface upon focusing; and a second lens group having a positive refractive power, which moves along the optical axis upon focusing, wherein: the first lens group includes: a first partial lens group that comprises at least two positive lenses and has a positive refractive power; and a negative lens, the second lens group includes: at least one meniscus lens with a convex surface thereof facing the object side; a second partial lens group that includes at least one negative lens and at least one positive lens, and has a positive refractive power; and a cemented lens that is formed by bonding together a plurality of lenses and has a positive refractive power, wherein: a predetermined conditional expression is satisfied.
    Type: Grant
    Filed: January 21, 2016
    Date of Patent: May 28, 2019
    Assignee: Nikon Corporation
    Inventors: Haruo Sato, Issei Tanaka
  • Publication number: 20190155005
    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 31, 2018
    Publication date: May 23, 2019
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Patent number: 10203488
    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: November 22, 2016
    Date of Patent: February 12, 2019
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Publication number: 20180024315
    Abstract: An optical system includes, disposed in sequence along an optical axis starting on an object side: a first lens group having a positive refractive power, which remains fixed relative to an image surface upon focusing; and a second lens group having a positive refractive power, which moves along the optical axis upon focusing, wherein: the first lens group includes: a first partial lens group that comprises at least two positive lenses and has a positive refractive power; and a negative lens, the second lens group includes: at least one meniscus lens with a convex surface thereof facing the object side; a second partial lens group that includes at least one negative lens and at least one positive lens, and has a positive refractive power; and a cemented lens that is formed by bonding together a plurality of lenses and has a positive refractive power, wherein: a predetermined conditional expression is satisfied.
    Type: Application
    Filed: January 21, 2016
    Publication date: January 25, 2018
    Inventors: Haruo SATO, Issei TANAKA
  • Publication number: 20170315337
    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; 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 first lens group G1 being fixed in the position in the direction of the optical axis, at least the second lens group G2 and the third lens group G3 being moved in the direction of the optical axis such that a distance between the first lens group G1 and the second lens group G2 is increased and a distance between the second lens group G2 and the third lens group G3 is decreased; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which can suppress variations in aberrations upon zooming and having excellent optical performance from a wide angle end state to a telephoto end state, an optical apparatus, and a
    Type: Application
    Filed: July 14, 2017
    Publication date: November 2, 2017
    Inventors: Satoshi YAMAGUCHI, Issei TANAKA
  • Patent number: 9791678
    Abstract: A zoom lens has, in order from an object: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having positive refractive power. Zooming is performed by changing an air gap between the lens groups. The fourth lens group includes, in order from the object, a first positive lens component, a second positive lens component having a convex surface facing the object, and a negative lens component. A specified conditional expression is satisfied.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: October 17, 2017
    Assignee: Nikon Corporation
    Inventors: Haruo Sato, Issei Tanaka
  • Patent number: 9753271
    Abstract: An eyepiece lens (EL) used for a viewfinder optical system (VF) for viewing, using the eyepiece lens (EL), an image formed by an objective lens (OL), an image displayed by a display member, or an object, wherein an antireflection coating (101) is disposed on at least one surface among the optical surfaces constituting the eyepiece lens (EL), and the antireflection coating (101) includes at least one layer (101g) formed by a wet process.
    Type: Grant
    Filed: March 5, 2016
    Date of Patent: September 5, 2017
    Assignee: Nikon Corporation
    Inventors: Issei Tanaka, Hiroki Harada, Taku Matsuo
  • Patent number: 9726869
    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; 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 first lens group G1 being fixed in the position in the direction of the optical axis, at least the second lens group G2 and the third lens group G3 being moved in the direction of the optical axis such that a distance between the first lens group G1 and the second lens group G2 is increased and a distance between the second lens group G2 and the third lens group G3 is decreased; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which can suppress variations in aberrations upon zooming and having excellent optical performance from a wide angle end state to a telephoto end state, an optical apparatus, and a
    Type: Grant
    Filed: February 8, 2015
    Date of Patent: August 8, 2017
    Assignee: Nikon Corporation
    Inventors: Satoshi Yamaguchi, Issei Tanaka
  • Patent number: 9625689
    Abstract: An optical system SL installed in a single-lens reflex camera includes, in order from an object side, a first lens group G1, a second lens group G2 having negative refractive power, and a third lens group G3 having positive refractive power. The second lens group G2 is disposed movably in a direction including a component perpendicular to an optical axis, and a given conditional expression is satisfied, thereby providing an optical system having excellent optical performance with excellent vibration reduction performance, an optical apparatus equipped with the optical system, and a method for manufacturing the optical system.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: April 18, 2017
    Assignee: Nikon Corporation
    Inventors: Hiroki Harada, Issei Tanaka
  • Publication number: 20170082837
    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: November 22, 2016
    Publication date: March 23, 2017
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Patent number: 9523843
    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: July 29, 2011
    Date of Patent: December 20, 2016
    Assignee: Nikon Corporation
    Inventors: Akihiko Obama, Norikazu Yokoi, Issei Tanaka
  • Publication number: 20160187641
    Abstract: An eyepiece lens (EL) used for a viewfinder optical system (VF) for viewing, using the eyepiece lens (EL), an image formed by an objective lens (OL), an image displayed by a display member, or an object, wherein an antireflection coating (101) is disposed on at least one surface among the optical surfaces constituting the eyepiece lens (EL), and the antireflection coating (101) includes at least one layer (101g) formed by a wet process.
    Type: Application
    Filed: March 5, 2016
    Publication date: June 30, 2016
    Inventors: ISSEI TANAKA, HIROKI HARADA, TAKU MATSUO
  • Patent number: 9354430
    Abstract: A zoom lens including, from an object: a front group having negative power; and a rear group having positive power, the rear group including, from the object, a positive lens, a negative lens having a concave surface facing the object, a cemented positive lens constructed by a negative lens and a positive lens, and a cemented lens constructed by a positive lens and a negative lens, the rear group further including a focusing group disposed to the object side of the positive lens La for focusing from infinity to a close object by moving from the object side to an image side, a distance between the front group and the rear group being varied thereby zooming from a wide-angle end state to a telephoto end state, and given condition being satisfied, thereby providing a downsized zoom lens having wide angle of view and excellent optical performance with fewer lenses.
    Type: Grant
    Filed: August 18, 2014
    Date of Patent: May 31, 2016
    Assignee: Nikon Corporation
    Inventors: Haruo Sato, Issei Tanaka
  • Publication number: 20150153550
    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; 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 first lens group G1 being fixed in the position in the direction of the optical axis, at least the second lens group G2 and the third lens group G3 being moved in the direction of the optical axis such that a distance between the first lens group G1 and the second lens group G2 is increased and a distance between the second lens group G2 and the third lens group G3 is decreased; and a predetermined conditional expression being satisfied, thereby providing a variable magnification optical system which can suppress variations in aberrations upon zooming and having excellent optical performance from a wide angle end state to a telephoto end state, an optical apparatus, and a
    Type: Application
    Filed: February 8, 2015
    Publication date: June 4, 2015
    Inventors: Satoshi YAMAGUCHI, Issei TANAKA
  • Patent number: 9030755
    Abstract: A zoom lens optical system includes, in order from an object side along an optical axis: 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 negative refractive power; and a fifth lens group having positive refractive power, wherein upon zooming from a wide-angle end state to a telephoto end state, the first lens group being moved with respect to an image plane, a distance between the first lens group and the second lens group increasing, a distance between the second lens group and the third lens group decreasing, a distance between the third lens group and the fourth lens group varying, and a distance between the fourth lens group and the fifth lens group varying.
    Type: Grant
    Filed: January 25, 2012
    Date of Patent: May 12, 2015
    Assignee: Nikon Corporation
    Inventors: Issei Tanaka, Norikazu Yokoi, Akihiko Obama
  • Patent number: 9007703
    Abstract: An imaging lens SL comprising, in order from an object side: a first group G1 having positive refractive power; an aperture stop S; a second group G2 having positive refractive power; and a third group G3 having negative refractive power; upon focusing from infinity to a close object, the first group and the second group moving independently along an optical axis toward the object side, the first group including, in order from the object side, a front group having negative refractive power, and a rear group having positive refractive power, and the front group consisting of, in order from the object side, a positive lens and a negative lens, thereby providing an imaging lens capable of obtaining excellent optical performance upon focusing from infinity to a close object, with downsizing the optical system with a simple lens construction, an optical apparatus and a method for manufacturing the imaging lens.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: April 14, 2015
    Assignee: Nikon Corporation
    Inventors: Motohisa Mouri, Issei Tanaka
  • Patent number: 8941921
    Abstract: An 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. The second lens group is moved upon carrying out focusing from an infinitely distant object to a close object, at least a portion of the third lens group is moved in a direction including a component perpendicular to an optical axis, and given conditional expressions is satisfied. Accordingly, an optical system excellently suppressing variations in aberrations generated upon vibration reduction, an optical apparatus equipped therewith, and a method for manufacturing the optical system are provided.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: January 27, 2015
    Assignee: Nikon Corporation
    Inventors: Tomoki Ito, Issei Tanaka