Patents by Inventor Yoshifumi Tokoyoda

Yoshifumi Tokoyoda 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: 20090273841
    Abstract: A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5?D/DS?0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d1S and that of the second diffractive element d2S, and D denotes the summation of an actual groove height of the first diffractive element d1and that of the second diffractive element d2. At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.
    Type: Application
    Filed: June 30, 2009
    Publication date: November 5, 2009
    Inventor: Yoshifumi TOKOYODA
  • Patent number: 7554733
    Abstract: A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5?D/DS?0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d1S and that of the second diffractive element d2S, and D denotes the summation of an actual groove height of the first diffractive element d1 and that of the second diffractive element d2. At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: June 30, 2009
    Assignee: Nikon Corporation
    Inventor: Yoshifumi Tokoyoda
  • Publication number: 20060268414
    Abstract: A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5?D/DS?0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d1S and that of the second diffractive element d2S, and D denotes the summation of an actual groove height of the first diffractive element d1 and that of the second diffractive element d2. At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.
    Type: Application
    Filed: August 10, 2006
    Publication date: November 30, 2006
    Inventor: Yoshifumi Tokoyoda
  • Patent number: 7042642
    Abstract: A diffractive optical element includes a first diffractive element and a second diffractive element that is made of a material different from that of the first diffractive element and is cemented with the first diffractive element, forming a diffraction grating at the cemented surface. A shade film is formed on a wall surface of each groove of the diffraction grating to enhance the angular characteristic of the grating.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: May 9, 2006
    Assignee: Nikon Corporation
    Inventors: Yoshifumi Tokoyoda, Kenzaburo Suzuki
  • Publication number: 20050018299
    Abstract: The object is providing a multi-layer type diffractive optical element enhancing angular characteristic. A diffractive optical element includes a first diffractive element 6 and a second diffractive element 7 that is made of a material different from the first diffractive element 6 and is cemented with the first diffractive element 6 forming a diffraction grating 1 at the cemented surface. A shade film 5a is formed on a wall surface 3 of the groove of the diffraction grating 1.
    Type: Application
    Filed: September 30, 2003
    Publication date: January 27, 2005
    Inventors: Yoshifumi Tokoyoda, Kenzaburo Suzuki
  • Publication number: 20030161044
    Abstract: A diffractive optical element includes at least a first diffractive element and a second diffractive element. The conditional expression 0.5≦D/DS≦0.9 is preferably satisfied where DS denotes the summation of the optimum designed groove height of the first diffractive element d1S and that of the second diffractive element d2S, and D denotes the summation of an actual groove height of the first diffractive element d1 and that of the second diffractive element d2. At least one of the first diffractive element and the second diffractive element is made of glass. At least one of the first diffractive element and the second diffractive element is made of resin. The optimum designed value of groove heights of the diffractive optical element are determined so as to satisfy a condition for correcting chromatic aberration at both d-line and g-line.
    Type: Application
    Filed: January 31, 2003
    Publication date: August 28, 2003
    Applicant: Nikon Corporation
    Inventor: Yoshifumi Tokoyoda
  • Patent number: 5739898
    Abstract: The present invention relates to a projection exposure method and an exposure apparatus for projecting a pattern on a photo-mask through a projection optical system onto a predetermined photosensitive material. The photosensitive material is a nonlinear photosensitive material in which the effective light intensity distribution is nonlinear to the intensity of incident exposure light. Further, multiple exposure is made with plural patterns having a certain lateral shift therebetween, or multiple exposure is made with shifting the position of an identical pattern, whereby multiple exposure is effected with patterns different in intensity distribution on the photosensitive material. A high-resolution pattern can be formed over the resolution limit of projection optical system by the above arrangement.
    Type: Grant
    Filed: September 26, 1994
    Date of Patent: April 14, 1998
    Assignee: Nikon Corporation
    Inventors: Toshihiko Ozawa, Masaya Komatsu, Masato Shibuya, Hiroshi Ooki, Masaomi Kameyama, Yoshifumi Tokoyoda