Patents by Inventor Isao Sasao

Isao Sasao 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: 4924416
    Abstract: An apparatus detects the degree of crowding in an elevator hall utilizing a television camera to provide video signals which are stored as video data and including an illumination controller which controls the brightness of an illuminator for the elevator hall when the difference between reference data and video data has exceeded a predetermined value and has continued for a predetermined time, so that the difference between the reference data and the video data may fall within the predetermined value.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: May 8, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4779708
    Abstract: A control device for an elevator which automatically regulates an offset to correct the offset amount contained in a control signal applied to the base circuit of an inverter for driving the hoisting motor of the elevator with a regulator for generating the control signal to detect the output current of the inverter while the elevator is stopped to operate to correct the current to a predetermined value or lower, thereby holding the corrected value even during the operation of the elevator.
    Type: Grant
    Filed: January 12, 1988
    Date of Patent: October 25, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Isao Sasao, Yoshio Miyanishi, Takanobu Masaki
  • Patent number: 4704597
    Abstract: An elevator cage travel detector includes an apertured disc 8 whose rotational movement is sensed by a photo encoding pulse generator 9 which produces two phase displaced outputs 10b, 11b. To prevent motion detection errors due to false generations of one of the pulse outputs when the cage is at rest, due to vibrations or the like, each pulse train is fed to both its own flip-flop 14C, 14D and to a leading and trailing edge detector 14A, 14B whose output enables a flip-flop for the other pulse train. The further processing of the two pulse trains is thus mutually dependent upon the continuing generation of both of them.
    Type: Grant
    Filed: January 26, 1983
    Date of Patent: November 3, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4671391
    Abstract: A moving distance detector for an elevator including an encoder pulse receiver having a differential amplifier for receiving input signal pulses generated upon movement of an elevator cage and transmitted on first and second signal transmission lines. Resistors are respectively connected between the first signal transmission line and a first input terminal of the differential amplifier and between the second signal transmission line and a second input terminal thereof to provide a difference between the low and high voltage signals at the first and second input terminals of the differential amplifier. Since the biasing voltage of a signal provided at one of the input terminals of the differential amplifier when the corresponding transmission line is interrupted is set to be sufficiently different from the high or low voltage level of the signal at the other input terminal, an output representing a fault or unstable state in the balancing transmission lines is readily produced.
    Type: Grant
    Filed: May 19, 1986
    Date of Patent: June 9, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4614931
    Abstract: A call system for an elevator includes a call button and call registration lamp connected to two electrodes of a thyristor. The third electrode is connected to a conversion circuit. The conversion circuit is connected to a control device. The control device determines whether the call signal is to be effective at a given time. The conversion circuit receives the call signal and the indication of effectiveness and forwards the call signal to the control device only when the signal is to be effective. The conversion device includes a memory for storing the state of effectiveness, a call signal detecting circuit and a driving circuit.
    Type: Grant
    Filed: March 19, 1982
    Date of Patent: September 30, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4520905
    Abstract: In an elevator group control apparatus in which a call by an elevator area call button is assigned to a cage to bring the cage to the user's floor, a second call device is provided separately from the call button. A desired time required for response by cage is designated by the second hall call device, the desired time is compared with an estimated time required for the arrival of car, and a cage is thereby selected to respond to the call. Thus, a cage is caused to serve a user with a minimum time delay.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: June 4, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4509013
    Abstract: A speed threshold value crossing detecting circuit which receives a pulse each time an object moves a unit distance has a time limit circuit activated by each pulse, a detector circuit determining whether the time limit of time limit circuit is over by the time of each successive pulse to detect whether the moving speed of the object has reached a preset speed, and a time limit control circuit for increasing the time limit of the time limit circuit when the detector circuit indicates that the preset speed has been reached. The hysteresis thus introduced in the time limit makes the detector circuit output turn uniformly on or off and suppresses the effect of small fluctuations in the pulse frequency not indicative of speed variations. Preferably the time limit of a retriggerable one-shot multivibrator is increased by selectively disconnecting an auxiliary resistor from the one-shot's RC time-setting network when the preset speed has been reached.
    Type: Grant
    Filed: November 18, 1982
    Date of Patent: April 2, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao
  • Patent number: 4376930
    Abstract: A call signal conversion apparatus for an elevator system comprises a call button device as a serial connection of a call button and a call registration lamp; a control device as a computer for inputting a call signal given by actuation of the call button, registering the calling and outputting the call registration signal; and a signal conversion circuit connected between the button device and the control device. The signal conversion circuit comprises a call detection circuit for detecting the call signal; a waveform shaper circuit which shapes the call signal to output the signal to the control circuit; a memory circuit for memorizing the call signal or the call registration signal; and a driving circuit for outputting the signal for turning on or off the call registration lamp by detecting the output of the memory circuit.
    Type: Grant
    Filed: January 26, 1981
    Date of Patent: March 15, 1983
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Isao Sasao