Patents by Inventor Yasuo Ishiguro

Yasuo Ishiguro 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: 4193673
    Abstract: The digital shutter control circuit comprises a reference clock pulse generating circuit, a binary counter circuit having a plurality of output stages each issuing, upon counting the pulses from the reference pulse generating circuit, output signals corresponding to the exposure time to be set in the shutter in terms of 2.sup.n where n is an integer and a selector circuit connected to the shutter closing means and selectively connectable to any of the output stages. The binary counter circuit is actuated simultaneously with the actuation of the shutter opening means for opening the shutter so that the shutter closing means is actuated when the output signal is issued from the output stage to which the selector circuit is connected thereby closing the shutter to provide the selected shutter speed.
    Type: Grant
    Filed: June 7, 1978
    Date of Patent: March 18, 1980
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Kenji Wakazono, Toshihisa Saito
  • Patent number: 4192595
    Abstract: An electroflash controlling circuit wherein, in order to make the fully open time of a shutter and the flashing time of a flash accurately coincide with each other, a delaying circuit operated by an electric signal for starting a shutter blade opening motion or an electric signal for starting a shutter blade closing motion is provided so that a flashing circuit may be triggered after the lapse of a delay time made by the delaying circuit.
    Type: Grant
    Filed: August 22, 1978
    Date of Patent: March 11, 1980
    Assignee: Copal Company Limited
    Inventors: Kenji Wakazono, Yasuo Ishiguro, Toshihisa Saito
  • Patent number: 4190344
    Abstract: A shutter driving circuit including a voltage judging circuit and indicating circuit in order to always properly make shutter opening and closing operations, whereby an electric current is prevented from flowing to driving coils and such state can be indicated by the indicating circuit when the voltage of a current source for feeding a current to a pair of driving coils to be made to make opening and closing motions of the shutter by the voltage judging circuit is below a predetermined value.
    Type: Grant
    Filed: December 9, 1977
    Date of Patent: February 26, 1980
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Kenji Wakazono
  • Patent number: 4161764
    Abstract: An exposure controlling circuit for electric shutters incorporating therein a voltage drop detecting circuit which will issue a signal for passing a current to a coil for closing a shutter when a current source voltage becomes lower than a predetermined voltage in order to prevent the shutter closing motion from being made unable to be made by the drop of the current source voltage after the shutter is opened. This controlling circuit further includes a driving circuit for making an indication within the field of vision of the view finder of a photographic camera when a signal is issued from the voltage drop detecting circuit.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: July 17, 1979
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Kenji Wakazono, Toshihisa Saito
  • Patent number: 4143958
    Abstract: A controlling circuit for electric shutters wherein, in an electric shutter adapted to start a shutter closing moton by energizing a driving coil with a discharge current from a capacitor, the capacitor is made to be discharged by a voltage drop detecting circuit provided so that the shutter may be positively closed even in case a current source switch is opened by an unexpected accident in the course of an exposure controlling operation.
    Type: Grant
    Filed: September 30, 1977
    Date of Patent: March 13, 1979
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Kenji Wakazono
  • Patent number: 4139282
    Abstract: A device is provided for indicating fading operation in cinecamera. A control circuit receives the scene light indicating voltage and a manually adjusted output voltage for operating a diaphragm driving means to adjust the aperture to a proper value for the scene brightness an RC circuit is connected to the diaphragm control circuit which selectively applys either a constant charging or discharging voltage to the diaphragm control circuit, this causes the control circuit to drive the diaphragm to continuously vary the aperture for effecting the fading-out and the fading-in of the scene. A first comparator receives the output voltage of the RC circuit and the output voltage of the diaphragm control circuit and produces a signal when both voltages are coincident.
    Type: Grant
    Filed: May 17, 1977
    Date of Patent: February 13, 1979
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Tomio Kurosu
  • Patent number: 4134653
    Abstract: The automatic diaphragm controlling device comprises an electric source, a servomotor having a single driving coil for driving a diaphragm of an objective lens, a scene light indicating voltage generating circuit and a reference voltage generating circuit energized by the electric source, respectively, the servomotor being controlled by the difference between the output voltages of both circuits so that a proper exposure is obtained.
    Type: Grant
    Filed: May 10, 1977
    Date of Patent: January 16, 1979
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Tomio Kurosu
  • Patent number: 4129370
    Abstract: A controlling circuit for electric shutters comprising at least one constant current circuit, a pair of capacitors to be charged in advance by a current source battery through the constant current circuit and a pair of driving coils to be energized in turn by discharge currents of the pair of capacitors to start a shutter blade opening motion and closing motion so that the current source battery of a comparatively small capacity may be effectively used.
    Type: Grant
    Filed: September 30, 1977
    Date of Patent: December 12, 1978
    Assignee: Copal Company Limited
    Inventors: Yasuo Ishiguro, Kenji Wakazono
  • Patent number: 4006976
    Abstract: Fade-in and fade-out device used in a cinecamera having an automatic exposure control circuit including a photoelectric element receiving light from scene through the diaphragm of the taking lens for generating an output voltage indicative of the scene brightness, a capacitor for generating an output voltage used as a reference voltage and a servoamplifier for comparing the output voltages of the photoelectric element and the capacitor so that an output, the sense of which is dependent on the values of the outputs of the photoelectric element and the capacitor and which is continuingly generated until both the outputs of the photoelectric element and the capacitor become equal to each other, is supplied to an actuating means for the diaphragm of the taking lens so as to control the same for the proper exposure.
    Type: Grant
    Filed: July 16, 1975
    Date of Patent: February 8, 1977
    Assignee: Copal Company Limited
    Inventor: Yasuo Ishiguro