Patents by Inventor Keiji Ohsawa

Keiji Ohsawa 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: 5612762
    Abstract: A focus detection device for a camera capable of detecting focuses at a plurality of areas on a photographing field, comprises two pairs of photo-electric conversion device arrays arranged on one substrate in optical correspondence to two of said plurality of areas; the two areas being arranged on a line extending generally vertically to a horizontal center axis crossing an optical line on the photographing field, on the opposite sides of the center line; and a refocusing optical system for refocusing light beams passing through different points of an exit pupil of a photographing lens, onto the two pairs of photo-electric conversion device arrays; the refocusing optical system including a pair of refocusing lenses for focusing the light beams onto the two pairs of photo-electric conversion device arrays.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: March 18, 1997
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5576896
    Abstract: Fitting holes are formed on a line of extension or a substantially vertical bisector in an arranging direction of a pair of lenses of a plastic plate formed integrally with at least the pair of lenses. Correspondingly, bosses are formed protruding from a base body using an adherable material so that a height thereof is larger than a sum of a thickness of the plastic plate and a thickness of a stop plate. Even after attaching the stop plate and the plastic plate to the base body, the bosses are protrudable from the plastic plate. Thus, the plastic plate and the stop plate are fixed in a sandwiched state between the base body and an adhesive agent. The plastic lens having a poor adhesion with the adhesive agent can be surely fixed without increasing the number of parts, and an instability of a positional accuracy due to environmental changes is obviated.
    Type: Grant
    Filed: December 8, 1994
    Date of Patent: November 19, 1996
    Assignee: Nikon Corporation
    Inventors: Naoki Kitaoka, Keiji Ohsawa
  • Patent number: 5572013
    Abstract: A focus detection apparatus adapted to reform images of light fluxes that pass through differing regions of a photographic lens into a pair of images on light receiving element arrays by using, for each pair of images, a field mask, a field lens, a pair of re-imaging lenses and an aperture mask having a pair of aperture openings provided in the vicinity of the pair of re-imaging lenses. The focus detection apparatus has multiple focus detection blocks that detect the focus condition of the photographic lens from positions relative to the pairs of images. The focus detection apparatus is further adapted to detect the focus condition of multiple areas on a focal plane. The focus detection apparatus includes a deflection mirror positioned between the field lens and the pair of re-imaging lenses. The deflection mirror causes the light fluxes to be deflected at nearly right angles for focus detection.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: November 5, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5561492
    Abstract: A camera body incorporates an information detecting portion for detecting respective pieces of information on photography with respect to a plurality of areas within a photographing picture and an information selecting portion for selecting specific pieces of information from plural pieces of information. A remote control unit incorporates an area designating portion for designating an arbitrary area among the plurality of areas irrespective of a position of the remote control unit. The information selecting portion is constructed to select the information on the area designated by the area designating portion.
    Type: Grant
    Filed: August 18, 1994
    Date of Patent: October 1, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5546157
    Abstract: A focus detection device includes a sensor for detecting focus in at least two regions of an image field. The device further includes a photographic lens for receiving light from a source in the image field, and a field lens for receiving light from the photographic lens. The field lens is disposed between the photographic lens and the sensor, and includes a plurality of field lens elements for receiving light from the regions of the image field. At least two of the field lens elements are adjacent field lens elements corresponding to adjacent regions of the image field. The adjacent field lens elements are separated by a space to deflect stray light. A method of use also is described.
    Type: Grant
    Filed: December 27, 1994
    Date of Patent: August 13, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5530513
    Abstract: A focus-detecting device for receiving light rays from a photographic field to detect a state of focus of a lens includes a sensor positioned to receive light rays from the photographic field. The sensor includes a plurality of sensor elements, at least one of the sensor elements being adjustably positionable independently of another of the sensor elements. A plurality of light-receiving components are coupled with the sensor elements to receive the light rays transmitted from the photographic field. The light-receiving components are grouped into a plurality of detectors coupled with one of the sensor elements to detect different areas in the photographic field to detect a state of focus of the lens. A method of use also is disclosed.
    Type: Grant
    Filed: December 9, 1994
    Date of Patent: June 25, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5506399
    Abstract: A focus detection device is provided that can quickly detect small displacements with high precision in the optical image on arrays of photosensitive elements. The device includes a pair of arrays of photosensitive elements made of rectangular photosensitive elements arranged in a single line and positioned so that the boundary lines D between adjacent photosensitive elements are orthogonal to the direction in which the photosensitive elements are aligned. The boundary lines D are also inclined at a preset angle from the direction corresponding to vertical or horizontal lines in the image field. When the arrays of photosensitive elements and components peripheral to these arrays are solidly attached to a rectangular substrate, the arrays of photosensitive elements are positioned so that the direction in which the photosensitive elements are aligned is parallel to the sides of the perimeter of the substrate.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: April 9, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5500708
    Abstract: A focus detection device includes an infrared reduction filter positioned behind the field lens between, the field lens and any secondary imaging lenses. Preferably, the infrared reduction filter is positioned closely adjacent to the field lens, i.e., closer to the field lens than to the secondary imaging lenses, usually between the field lens and any deflection mirror that might be located between the field lens and the secondary imaging lenses.
    Type: Grant
    Filed: October 19, 1994
    Date of Patent: March 19, 1996
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5500519
    Abstract: In order to obtain a focus detection device that can perform pupil adjustment accurately in all of a plurality of focus detection areas, field lenses corresponding to each focus detection area in a focus detection device having a plurality of focus detection areas are comprised of separate materials for each focus detection area, and independent adjustment of the eccentricity of the field lens corresponding to each focus detection area is made possible in the plane perpendicular to the optical axis of each field lens so that pupil adjustment can be performed independently for each of the plurality of focus detection areas.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: March 19, 1996
    Assignee: Nikon Corporation
    Inventors: Naoki Kitaoka, Keiji Ohsawa
  • Patent number: 5499074
    Abstract: An autofocus camera conducts a focus detection operation with one of differently directed sets of photoelectric conversion elements which is given priority according to the detected attitude of the camera. If focusing cannot be effected using the elements given priority, a focus detection operation is automatically conducted with the other elements. Also provided is a camera having a first mode of operation in which focusing detecting operations are conducted which collectively utilize outputs of all of the elements of differently directed sets of photoelectric conversion elements when a first camera attitude is detected, and a second mode of operation in which focusing detecting operations are conducted which collectively disregard the output of at least one conversion element when a second camera attitude is detected.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: March 12, 1996
    Assignee: Nikon Corporation
    Inventors: Keiji Ohsawa, Nobuo Matsukawa, Sunao Nishioka, Ryuichi Mori, Yoshiyuki Nakano
  • Patent number: 5393969
    Abstract: A focus state detecting device of divided-pupil phase difference system, having plural distance measuring areas, in which photosensors are provided respectively corresponding to the distance measuring areas in the image field in order to effect focus state detection in the plural distance measuring areas, and at least a part of the photosensors are constructed as an independent unit separate from others, whereby optical adjustment is rendered possible independently in each distance measuring area.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: February 28, 1995
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 5361119
    Abstract: There is disclosed a focus state display device, adapted for use in a camera which has plural focus detection areas in the phototaking image field and effects focusing in one area (focusing area) selected from such plural focus detection areas. The device has a display with two different display modes, and displays the focusing area in one display mode when the lens of the camera is in an infocus state to the object in the focusing area, and in the other display mode when the lens is in an out-of-focus state to the object in the focusing area. In another embodiment, the device has a display with three different display modes, and displays the focusing area by a display mode and other focus detection areas (namely nonfocusing areas) by two other display modes depending on whether the object in respective area is in focus or out of focus.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: November 1, 1994
    Assignee: Nikon Corporation
    Inventors: Masaru Shida, Akira Ezawa, Tsutomu Wakabayashi, Kimio Uematsu, Keiji Ohsawa, Shinichi Tsukada, Toshihiro Sato
  • Patent number: 5122827
    Abstract: A camera comprises a penta-roof prism, a plurality of inclined sensors respectively disposed at positions opposed to corresponding inclined planes of the prism, and an attitude detector for detecting the attitude of the camera in response to outputs of the sensors. Each sensor is capable of producing either of two outputs, and the outputs of the sensors are combined to produce a number of pieces of attitude information. This information is classified to provide a smaller number of pieces of attitude information from which the attitude of the camera is determined.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: June 16, 1992
    Assignee: Nikon Corporation
    Inventors: Takashi Saegusa, Kenji Isono, Tetsuro Goto, Keiji Ohsawa
  • Patent number: 4972222
    Abstract: An exposure controlling apparatus for a camera, comprises a divided photometry device for performing photometry regarding an object field through a taking lens by dividing the object field into a plurality of areas, a central portion photometry device for performing photometry regarding a central area of the object field through the taking lens, a lens information output device for outputting lens information representative of a quantitive optical feature of the taking lens, a comparison device, including reference value information, for comparing the lens information with the reference value information, and an exposure determination means, responsive to the comparison device, for determining an exposure value regarding the object field in accordance with the divided photometry device when the lens information does not exceed the reference value information, and for determining an exposure value regarding the object field in accordance with the central portion photometry device when the lens information exce
    Type: Grant
    Filed: May 2, 1989
    Date of Patent: November 20, 1990
    Assignee: Nikon Corporation
    Inventors: Toshihiro Sato, Tadao Takagi, Keiji Ohsawa
  • Patent number: 4833494
    Abstract: A single lens reflex camera having a replaceable view finder unit, wherein it includes an electric circuit therein, said electric circuit capable of being connected to an electric circuit in a camera body through the medium of contact means is characterized in that the replaceable view finder unit includes a housing into which at least a pentagonal roof prism and an eye piece portion are arranged, and a signal contact of a contact means for electrically connecting the electric circuit in the view finder unit to the electric circuit in the camera body is arranged on a bottom of the housing below the eye piece portion.
    Type: Grant
    Filed: March 11, 1988
    Date of Patent: May 23, 1989
    Assignee: Nikon Corporation
    Inventor: Keiji Ohsawa
  • Patent number: 4775229
    Abstract: A Fresnel lens provided in the finder of a camera includes a central portion through which an optic axis passes, and a plurality of annular portions spaced apart from the central portion and disposed concentrically. The central portion and the plurality of annular portions have their respective focal lengths. The focal length of the central portion is shorter than the focal length of one of the annular portions which is remotest from the optic axis.
    Type: Grant
    Filed: February 19, 1986
    Date of Patent: October 4, 1988
    Assignee: Nippon Kogaku K. K.
    Inventors: Yutaka Ichihara, Daijiro Fujie, Keiji Ohsawa
  • Patent number: 4437747
    Abstract: An electronic flash mounting device enables operation of the rewinding knob while the flash unit is kept in the mounted position on a camera body having an accessory shoe around the knob and a flash synchronizing signal transmission terminal.
    Type: Grant
    Filed: April 16, 1982
    Date of Patent: March 20, 1984
    Assignee: Nippon Kogaku K.K.
    Inventors: Masato Ohno, Keiji Ohsawa