Patents by Inventor Kazumitsu Takezawa

Kazumitsu Takezawa 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: 6742940
    Abstract: A shading device employed in a lens barrel having a plurality of lens groups includes a plurality of substantially tubular shading members provided between a first lens group and a second lens group that move relative to each other along the optical axis and overlap each other along the optical axis so as to allow the shading device to achieve a telescopic function.
    Type: Grant
    Filed: August 29, 2002
    Date of Patent: June 1, 2004
    Assignee: Nikon Corporation
    Inventors: Norikatsu Konno, Hitoshi Imanari, Hideo Kanno, Kazumitsu Takezawa
  • Publication number: 20030091346
    Abstract: A shading device employed in a lens barrel having a plurality of lens groups includes a plurality of substantially tubular shading members provided between a first lens group and a second lens group that move relative to each other along the optical axis and overlap each other along the optical axis so as to allow the shading device to achieve a telescopic function.
    Type: Application
    Filed: August 29, 2002
    Publication date: May 15, 2003
    Applicant: NIKON CORPORATION
    Inventors: Norikatsu Konno, Hitoshi Imanari, Hideo Kanno, Kazumitsu Takezawa
  • Patent number: 6542313
    Abstract: A position detecting device is used with a lens barrel that includes an optical system, an optical system driving member that moves at least part of the optical system, and a driving force transmitting member that transmits rotational driving force from a driving source to the optical system driving member. The position detecting device includes a linear moving member that converts rotational motion of the driving force transmitting member into a linear motion, and a detector that detects the linear movement of the linear moving member. This arrangement is capable of providing a very compact structure. The driving force transmitting member can be a rotating shaft-like member that rotates through at least one rotation. The position detecting device also can include a backlash eliminating member (e.g., a spring) that eliminates a backlash between the driving force transmitting member and the linear moving member.
    Type: Grant
    Filed: November 29, 2001
    Date of Patent: April 1, 2003
    Assignee: Nikon Corporation
    Inventors: Hitoshi Imanari, Kazumitsu Takezawa
  • Publication number: 20020063971
    Abstract: A position detecting device is used with a lens barrel that includes an optical system, an optical system driving member that moves at least part of the optical system, and a driving force transmitting member that transmits rotational driving force from a driving source to the optical system driving member. The position detecting device includes a linear moving member that converts rotational motion of the driving force transmitting member into a linear motion, and a detector that detects the linear movement of the linear moving member. This arrangement is capable of providing a very compact structure. The driving force transmitting member can be a rotating shaft-like member that rotates through at least one rotation. The position detecting device also can include a backlash eliminating member (e.g., a spring) that eliminates a backlash between the driving force transmitting member and the linear moving member.
    Type: Application
    Filed: November 29, 2001
    Publication date: May 30, 2002
    Applicant: NIKON CORPORATION
    Inventors: Hitoshi Imanari, Kazumitsu Takezawa
  • Patent number: 6239923
    Abstract: A lens barrel including an iris stop unit which is easily secured in the lens barrel. The lens barrel includes a lens group holding frame fixed by screws to a moving tube which holds a lens group in a manner freely slidable in a forward or backward direction. A support ring is formed integrally with the moving tube, and the support ring, along with blades and a drive ring forms an iris stop unit. The blades and the drive ring are set at a designated position and the lens group holding frame is inserted into the moving tube and connected by screws. The drive ring is held by the front end of the lens group holding frame.
    Type: Grant
    Filed: August 27, 1999
    Date of Patent: May 29, 2001
    Assignee: Nikon Corporation
    Inventor: Kazumitsu Takezawa
  • Patent number: 6002532
    Abstract: There is disclosed a lens barrel which comprises a supporting frame for supporting lens groups, a cam barrel to be rotated around the optical axis to move the supporting frame in the direction of the optical axis in a predetermined range, a manual focusing ring to which the operator supplies a manual power, a manual power transmission mechanism to be moved by the manual power supplied to the manual focusing ring to rotate the cam barrel, a first limitation member for inhibiting the power transmission from the manual focusing ring to the cam barrel by limiting the movement of the manual power transmission mechanism when the supporting frame is moved to a vicinity of one end of the predetermined range by the rotation of the cam barrel, a motor power transmission mechanism for transmitting the motive power supplied from the motor to the cam barrel so as to rotate the cam barrel, and a second limitation member for limiting the rotation of the cam barrel, wherein the second limitation member is provided at a posit
    Type: Grant
    Filed: June 2, 1998
    Date of Patent: December 14, 1999
    Assignee: Nikon Corporation
    Inventor: Kazumitsu Takezawa
  • Patent number: 5926323
    Abstract: In a lens barrel which drives a focusing optical system using only one set of a cam groove and a cam pin engaged with the cam groove, the cam groove and the cam pin jointly defining a zooming operation and a focusing operation of the focusing optical system, to increase an automatic focusing speed, there is provided with a manual driving section rotated around an optical axis, an automatic driving section rotated around the optical axis and a rotation straight advance converting section for driving the focusing optical system after converting the rotational motion of the manual driving section or the automatic driving section into a straight advance motion by using only set of the cam groove and the cam pin for jointly defining the zooming and focusing operations of the focusing optical system. The manual driving section, the automatic driving section and the rotation straight advance converting section are interlocked with one another.
    Type: Grant
    Filed: April 15, 1997
    Date of Patent: July 20, 1999
    Assignee: Nikon Corporation
    Inventor: Kazumitsu Takezawa
  • Patent number: 5815094
    Abstract: A position detecting device comprises a pattern member having conductive patterns arranged in plural tracks; a slidable member having plural sliding pieces capable of sliding on the conductive patterns, wherein each of the sliding pieces assumes either a conductive state in contact with one of the conductive patterns or a non-conductive state not in contact with the conductive pattern; a signal processing device for detecting sets of the conductive patterns and the sliding pieces in conductive state, by transmitting electrical signals through the conductive patterns and the sliding pieces; and a discriminating device for identifying the relative position between the conductive patterns and the sliding pieces when the the conductive patterns and the sliding pieces in conductive state are detected at least a predetermined number of times or over at least a predetermined period of time.
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: September 29, 1998
    Assignee: Nikon Corporation
    Inventors: Hiroshi Okano, Yoshiharu Shiokama, Shinichi Ushio, Kazumitsu Takezawa
  • Patent number: 5627683
    Abstract: A lens barrel which has a lens holding member for holding a lens unit, a movement cam mechanism for moving the lens holding member in an optical-axis direction, a biasing member for biasing the lens holding member to shift a slide allowance of the movement cam mechanism in one direction, a biasing force receiving member for receiving a biasing force of the biasing member and a biasing force adjustment cam mechanism for moving the biasing force receiving member in the optical-axis direction so that the biasing force of the biasing member remains the same.
    Type: Grant
    Filed: December 13, 1995
    Date of Patent: May 6, 1997
    Assignee: Nikon Corporation
    Inventor: Kazumitsu Takezawa
  • Patent number: 5041855
    Abstract: A lens assembly for an automatic focusing camera having an automatic focusing mode and a manual focusing mode comprises an optical system including a lens group shiftable along an optical axis to perform a focusing operation, a focusing operation member rotatable around the optical axis to shift the lens group along the optical axis to perform the focusing operation, a power drive device for power driving the focusing operation member, a focusing handling member rotatable around the focusing operation member to perform the focusing operation manually, a connection element including a plurality of engaging recesses formed in an outer periphery of the focusing operation member at predetermined intervals in a circumferential direction, and a connecting member shiftable in a radial direction to engage with one of the recesses, the connecting element being adapted to transmit the rotation of the manual focusing handling member to the focusing operation member through the connecting member, and a changing-over devi
    Type: Grant
    Filed: February 14, 1990
    Date of Patent: August 20, 1991
    Inventors: Kazumitsu Takezawa, Hideo Kanno, Sachio Ohmori