Patents by Inventor Ikuya Tsurukawa

Ikuya Tsurukawa 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: 4985719
    Abstract: An apparatus for preventing static electricity of a plastic lens has the plastic lens coated with a transparent conductive coating; and a conductive member for electrically connecting the coating of the plastic lens to an electric circuit within a camera such that static electricity of the plastic lens is guided to the electric circuit. The preventing apparatus may have a plastic lens coated with a transparent conductive coating; a first electric circuit electrically connected to the coating of the plastic lens through a first conductive member; a conductive pressure plate for pressing a film toward an aperture; a second electric circuit electrically connected to the pressure plate through a second conductive member; a third electric circuit electrically connected through a third conductive member to a magazine attached to a camera; and a device for making the potentials of the magazine, the pressure plate and the plastic lens equal to each other.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: January 15, 1991
    Assignee: Ricoh Company, Ltd.
    Inventors: Ikuya Tsurukawa, Kosaku Sawabe
  • Patent number: 4950061
    Abstract: A device for driving a varifocal lens, includes a first group frame supporting the first group of lenses therein in a movable manner for focussing and supported with the lens barrel inside said fixed frame movably in parallel with said optical axis, a second group frame supporting the second group of lenses therein in a fixed manner and supported with the first group frame inside the first group frame movably in parallel with said optical axis, at least three driver screw members disposed within the fixed frame in parallel with optical axis, at least three driver gear members held in mesh with the driver screw members respectively, and a drive unit for driving the driver gear members to thereby move the lens barrel frame and the first group frame by a predetermined amount respectively.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: August 21, 1990
    Assignee: Ricoh Company, Ltd.
    Inventors: Ikuya Tsurukawa, Kunihisa Yamaguchi, Kosaku Sawabe
  • Patent number: 4847648
    Abstract: A varifocal camera, comprising a photographic lens barrel having a photographic lens able to change the focal distance and adapted to move rearwardly when the photographic lens is transferred to the first focal distance side and move forwardly when the lens is transferred to the second focal distance side, a photographic lens barrier movable between the opening position at which the photographic lens is exposed and the closing position at which photographic lens is screened, and a finder barrier movable between the opening position at which the finder lens is exposed and the closing position at which the finder lens is screened.
    Type: Grant
    Filed: February 12, 1988
    Date of Patent: July 11, 1989
    Assignee: Ricoh Company, Ltd.
    Inventors: Kunihisa Yamaguchi, Kohichi Nishi, Ikuya Tsurukawa, Kosaku Sawabe
  • Patent number: 4831399
    Abstract: A finder switching apparatus in a two-focus camera in which a finder is switched in conjunction with switching of a lens of the camera between shorter and longer focuses. The finder switching apparatus has a spring mechanism which can amplify a displacement of a parallax correcting lens which is adapted to move in interlocking engagement with the lens barrel so that the mechanism for moving the parallax correcting lens can be small. Accordingly, the two-focus camera having the finder switching apparatus according to the present invention can be made compact, since the space required for storing the finder switching apparatus in the camera is small.
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: May 16, 1989
    Assignee: Ricoh Company, Ltd.
    Inventors: Ikuya Tsurukawa, Kohichi Nishi, Kunihisa Yamaguchi
  • Patent number: 4605295
    Abstract: A quick mirror return mechanism includes a return spring and a quick return setting member, which are formed, in the region where they abut against each other, so that as the return spring is stressed, the resilient force of the return spring is directed closer to the direction in which a setting pawl moves. A main mirror for a finder, a stationary member, a mirror-up lever, a main mirror drive, a sub-mirror and a sub-mirror driver form together a six-bar linkage wherein the main mirror moves upward while swinging back and the sub-mirror moves into overlapping relationship with the main mirror when the latter has completed its upward movement. The quick return mechanism which is biased with an increased force is disposed on a front panel of a camera, thus preventing any excessive force from being applied to a mirror box. A light receiving element unit is disposed in the bottom of the mirror box.
    Type: Grant
    Filed: August 9, 1984
    Date of Patent: August 12, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimi Ohno, Ikuya Tsurukawa, Tokio Ishino
  • Patent number: 4561747
    Abstract: An auto-focusing method includes a scanning step for scanning a pair of solid-state image sensors on which light from a subject of interest impinges as passing through a focusing lens, an A/D conversion step, a Fourier transformation step, a convolution operation step, a peak detection step for determining an amount of displacement of said lens from the results of said convolution, and a lens displacement step for displacing said lens according to the displacement amount thus determined. The present auto-focusing method is least susceptible to noises and not adversely affected by differences in contrast of the subject of interest.
    Type: Grant
    Filed: June 14, 1984
    Date of Patent: December 31, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimi Ohno, Ikuya Tsurukawa
  • Patent number: 4498754
    Abstract: A quick mirror return mechanism includes a return spring and a quick return setting member, which are formed, in the region where they abut against each other, so that as the return spring is stressed, the resilient force of the return spring is directed closer to the direction in which a setting pawl moves. A main mirror for a finder, a stationary member, a mirror-up lever, a main mirror drive, a sub-mirror and a sub-mirror driver form together a six-bar linkage wherein the main mirror moves upward while swinging back and the sub-mirror moves into overlapping relationship with the main mirror when the latter has completed its upward movement. The quick return mechanism which is biased with an increased force is disposed on a front panel of a camera, thus preventing any excessive force from being applied to a mirror box. A light receiving element unit is disposed in the bottom of the mirror box.
    Type: Grant
    Filed: January 12, 1983
    Date of Patent: February 12, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshimi Ohno, Ikuya Tsurukawa, Tokio Ishino