Patents Assigned to Seiko Koki Kabushiki Kaisha
  • Patent number: 3978499
    Abstract: A warning light display device for an electric shutter of a camera having an exposure time control circuit for determining the exposure time of an electric shutter in dependence upon at least the brightness of an object being photographed. A warning display circuit is connected with the exposure time control circuit and has a control transistor that receives the output of the exposure time control circuit and controls the visual indication of three stages of the warning display circuit comprising light emitting diodes that indicate adequate and inadequate exposure conditions. A reference time generating circuit is provided in the warning display circuit for developing a signal representative of a predetermined time duration and a control transistor thereof controls energization of the three stages as a function of a comparison of the exposure time duration developed by the exposure time control circuit and the predetermined time duration developed by the reference time generating circuit.
    Type: Grant
    Filed: January 15, 1975
    Date of Patent: August 31, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventors: Shinji Nagaoka, Shogo Kato, Yukio Nakamura
  • Patent number: 3962709
    Abstract: An exposure time control circuit for a camera shutter having a light-responsive element that controls charging of a capacitor as a function of the intensity of the light from a scene to be photographed. The charge of the capacitor at a certain level activates a switching circuit that initiates closing of the camera shutter. A light-intensity indicating circuit is directly connected to the light-responsive element for indicating the intensity of the light received from a scene to be photographed so that the camera shutter speed may be set accordingly. Photographic exposure and light readings are taken independently with control switches that need not make use of a change-over switch for connecting and disconnecting the light-intensity indicating circuit to the light-responsive element.
    Type: Grant
    Filed: December 17, 1974
    Date of Patent: June 8, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventors: Kiyoshi Kitai, Yukio Nakamura, Hiroaki Ishida, Shinji Nagaoka
  • Patent number: 3950772
    Abstract: A shutter having two groups of shutter blades. One group of shutter blades opens the shutter and a second group of blades closes the shutter. A shutter-opening actuation member releasably locked by a locking pawl when the shutter is cocked, actuates the shutter-opening group of shutter blades for taking an exposure. A shutter-closing actuation member releasably locked by a second locking pawl actuates the shutter-closing group of shutter blades for completing the taking of an exposure. An electromagnet in an exposure control circuit is energized during the taking of an exposure and deenergized to control the exposure time and terminate the exposure. A control member that controls the release of the control member by its locking pawl is biased by a single spring.
    Type: Grant
    Filed: April 30, 1974
    Date of Patent: April 13, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventors: Tadashi Nakagawa, Mitsuo Koyama, Eiichi Onda
  • Patent number: 3947858
    Abstract: An electronic camera shutter having a single spring that biases an armature lever in a direction for applying an electromagnet armature supported thereon against the electromagnet until the electromagnet, which is a part of an exposure time control circuit, is energized so that the armature is attracted. This same spring cooperates with a holding lever biasing it in a direction for engaging with the armature lever and driving it in a direction for separating the armature from the electromagnet to initiate closing of the shutter upon de-energization of the electromagnet at the end of the exposure time period controlled by the exposure time control circuit.
    Type: Grant
    Filed: October 10, 1974
    Date of Patent: March 30, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventor: Hiroaki Ishida
  • Patent number: 3946413
    Abstract: A camera shutter having a plurality of shutter blades operable from a shutter-closing operative position to a shutter-opening operative position and back to the shutter-closing operative position. An opening driving lever and a closing driving lever are provided for operating the shutter blades to their operative positions. A rebound preventing arrangement is provided by providing pins fixed on the opening and driving levers and making provision on a cocking lever for holding the driving levers from rebounding upon reaching their terminal operating positions in activating the shutter blades in opening and closing the shutter. The pins on the driving levers are engaged at these terminal positions by the locking lever and releasably held to preclude rebounding thereby to preclude rebounding of the shutter blades.
    Type: Grant
    Filed: December 31, 1974
    Date of Patent: March 23, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventors: Eiichi Onda, Mitsuo Koyama, Tadashi Nakagawa
  • Patent number: 3946414
    Abstract: An electric shutter with a positive motion device that insures positive action of the shutter. The shutter has a depressable release member that is restored by a spring when pressure thereon is released so that the release member is reset when the shutter is opened. When the shutter is cocked the mechanical positive motion device is mechanically releasably locked maintaining the shutter blade or blades against biasing springs. When the release member is depressed the shutter is opened and an electromagnet of an exposure control circuit is energized and an attractable lever in the positive motion device is held attracted by the energized electromagnet releasably controlling the release of members that release the shutter blade or blades for actuation to a shutter-closing position. A mechanical locking member in conjunction with a press lever in the positive control device positively locks the attractable lever in the same position as when attracted when the shutter is cocked.
    Type: Grant
    Filed: April 10, 1974
    Date of Patent: March 23, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventor: Kiyoshi Kitai
  • Patent number: 3938169
    Abstract: An electric shutter having a shutter release stop device that detects the absence of cocking of the shutter and that an electromagnet in the exposure control circuit of the shutter is not properly energized either because the battery is ineffective because it is expended or improperly connected in the circuit or not in the circuit. Detecting means initiates the action of a lock lever or bar that engages the camera shutter release lever and locks it so that it cannot be completely depressed for taking of an exposure. The taking of a photographic exposure is accordingly precluded and the waste of power and film is avoided.
    Type: Grant
    Filed: April 10, 1974
    Date of Patent: February 10, 1976
    Assignee: Seiko Koki Kabushiki Kaisha
    Inventor: Kiyoshi Kitai