Patents Assigned to The Nippon Signal Co., Ltd.
  • Patent number: 5872496
    Abstract: A slim-type small size electromagnetic relay is made using semiconductor manufacturing techniques to form a silicon substrate 2 having a planar movable plate 5 and a torsion bar 6 for axially supporting the movable plate 5 formed integrally therewith, with a planar coil 7 provided on an upper face of the movable plate 5 and a movable contact 9 provided on a lower face. Glass substrates 3, 4 are provided on upper and lower faces of the silicon substrate 2, with fixed contact 11 contactable with the movable contact 9 provided on the lower glass substrate 4. Permanent magnets 13A, 13B and 14A, 14B for producing a magnetic field at the planar coil 7 are fixed to the glass substrates 3, 4. Rotation of the movable plate 5 against the torsion force of the torsion bar 6 is controlled by passing a current through the planar coil 7 to produce a magnetic force, thereby causing contact or separation of the movable contact 9 and the fixed contact 11.
    Type: Grant
    Filed: November 1, 1995
    Date of Patent: February 16, 1999
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Norihiro Asada, Masayoshi Esashi
  • Patent number: 5867775
    Abstract: A fail-safe signal transmitting apparatus including a power supply which does not let a transmission output signal generate an error that would allow a dangerous situation to arise even when a multiple failure has occurred in circuits constituting the signal transmitting apparatus. In particular, the present invention includes a source failure monitoring function and in order to monitor the power supply, a fail-safe window comparator and a fail-safe ON delay circuit are employed. An output signal constituted of the logical product of source monitoring signal and a signal to be transmitted and a carrier signal is used as a transmission signal.
    Type: Grant
    Filed: June 28, 1996
    Date of Patent: February 2, 1999
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Toshihito Shirai, Hiroji Anzai, Koichi Futsuhara
  • Patent number: 5861813
    Abstract: A rotation detecting means detects rotation of a mechanical movable portion and outputs a detection signal corresponding to the rotation rate of the mechanical movable portion. A rotation monitoring circuit, to which the detection signal from the rotation detecting means is provided, outputs a rotation-existing signal when the detection signal indicates that the mechanical movable portion is rotating. A rotation stop monitoring circuit, to which the detection signal from the rotation detecting means is provided, outputs a rotation-stop signal when the detection signal indicates a rotation rate lower than a predetermined rotation rate, and a movable portion control circuit uses at least either the rotation-existing signal or the rotation-stop signal and an external command signal for input signals to control the mechanical movable portion with logic of these signals.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: January 19, 1999
    Assignee: The Nippon Signal, Co., Ltd.
    Inventor: Koichi Futsuhara
  • Patent number: 5825144
    Abstract: The invention relates to a drive control apparatus for a rotating machine having a movable part which is rotatably driven by a motor.The apparatus has a fail-safe construction which gives an output of logic value "1" when the movable part is stopped, wherein, to enable supply of motor current to start a motor (2) at the motor start-up time under a condition of the movable part stopped, motor drive permission is granted by a logical product output which is obtained by a logical product operation of a start signal generated by switching a start switch on, and a logical sum output obtained by a logical sum operation of an output of a current sensor (3) generating an output of logic value "1" when the motor current does not flow and an output of a rotation sensor (4) generating an output of logic value "1" when the movable part is rotating.
    Type: Grant
    Filed: July 16, 1995
    Date of Patent: October 20, 1998
    Assignees: Kao Corporation, The Nippon Signal Co., Ltd.
    Inventors: Masatoshi Suzuki, Koichi Futsuhara, Masayoshi Sakai
  • Patent number: 5818681
    Abstract: The invention relates to an electromagnetic relay drive circuit which generates an electromagnetic relay excitation signal after first verifying that the electromagnetic relay make contact points are off. A forced-operation electromagnetic relay with make contact points and break contact points having complementary relationship with each other is used, and when the break contact points are on, that is to say the make contact points are off, a trigger input signal of logic value "1" with a predetermined level range is applied to a trigger input terminal of a self hold circuit. When an input signal IN of logic value "1" within a predetermined level range is applied to a reset terminal while the trigger input signal is being applied, the relay is excited and the make contact points switch on.
    Type: Grant
    Filed: November 5, 1996
    Date of Patent: October 6, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Koichi Futsuhara, Masayoshi Sakai
  • Patent number: 5798703
    Abstract: The invention relates to a highly reliable mat sensor which can also detect temporary faults in a sensor portion. Two sensor portions are provided, and agreement or disagreement of an ON/OFF condition of the output from the two sensor portions is detected, and when the output conditions of the two sensor portions are in agreement, then a normal judgment signal for both sensor portions is generated. When the normal judgment signal is generated and the two sensor portions are OFF, an operation permit signal for a movable portion of a machine is generated. Moreover, the presence or absence of a body is detected from a change in value of the electrostatic capacity of one sensor portion. In this way, a temporary poor contact attributable to deterioration of the sensor portion can also be detected, and the movable portion of the machine can be stopped.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: August 25, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Koichi Futsuhara, Toshihito Shirai
  • Patent number: 5793197
    Abstract: A detection means 1 detects changes in impedance generated at a coil TC caused in response to indentations Py1 and Py2 and projections provided at the surface of a movable portion Rot to generate a detection signal thereof. A speed judgement circuit 2, to which the detection signal from the detection means is provided, continuously generates a high level output signal A2i when the detection signal e change interval becomes greater than a specific length of time. A level detection circuit 3, to which the detection signal e is provided, generates a high level output signal A1i when the detection signal e is at or above a specific level. An AND circuit 4, to which the output signal A2i from the speed judgement circuit 2 and the output signal A2i from the level detection circuit 3 are provided, generates an output signal Z resulting from AND calculation of the two output signals A1i and A2i.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: August 11, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Toshihito Shirai, Hiroji Anzai, Koichi Futsuhara
  • Patent number: 5793329
    Abstract: The presence/absence of an object, movement of the object, the direction of movement, the speed of movement, the shape of the object, the quantity of objects and time information related to these factors are detected without installing a means for transmission. An antenna device (1) has a function of receiving radio waves (EW1 to EW24) transmitted by GPS satellites and outputs a detection signal when the reception of the radio waves (EW1 to EW24) transmitted by the GPS satellites is blocked by an object (A). A signal processing device (2) detects the object (A) based upon the detection signal provided by the antenna device (1).
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: August 11, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Kenji Nakada, Makoto Yagi
  • Patent number: 5773972
    Abstract: A detector 1, with its object of detection having operation characteristics that include a shift from a first state to a second state, outputs a signal e1 that corresponds to the operation characteristics of the object of detection. A first state detection circuit 2 generates a first output signal SA corresponding to the first state based upon the signal e1 provided by the detector 1. A second state detection circuit 3 generates a second output signal SB corresponding to the second state based upon the signal provided by the detector 1. The second output signal SB is generated only when the object of detection shifts from the first state to the second state in a normal manner while the first output signal SA is being generated. A state judgement circuit 4 generates a state judgement output signal Z on condition that there has been a period of time during which the first output signal SA and the second output signal SB have been both at high.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: June 30, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Koichi Futsuhara, Toshihito Shirai
  • Patent number: 5768077
    Abstract: A leakage and earthing wire disconnection detection apparatus monitors for earthing wire disconnection and leakage of an electrical or electronic device during operation of the device. Two earthing wires are independently provided for the electrical or electronic device. The ends of the earthing wires on the electrical or electronic device side are electrically connected together, while earth-side ends are connected independently to earth. A single closed loop is made up of the two earthing wires, the electrical or electronic device, and earth. A detection circuit determines that the earthing wires are normal when the closed loop is closed, and abnormal when the closed loop is open. In addition, the apparatus performs leakage detection of a motor, or the like, based on a current level flowing in the earthing wires.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: June 16, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Koichi Futsuhara, Norihiro Asada
  • Patent number: 5767666
    Abstract: The present invention relates to a slim-type small size mirror galvanometer wherein the mirror displacement angle can be detected, made using semiconductor manufacturing techniques. Using semiconductor manufacturing techniques, a movable plate 5 and a torsion bar 6 for axially supporting the movable plate 5 are formed integrally on a silicon substrate 2, with a planar coil 7 and a total reflecting mirror 8 formed on an upper face of the movable plate 5, and permanent magnets 10A, 10B and 11A, 11B fixedly located so as to produce a magnetic field at the planar coil 7. The direction and quantity of current flowing in the planar coil 7 is controlled to variably control the swing angle of the movable plate 5 depending on the balance between the generated magnetic force and the torsion force in the torsion bar 6. Moreover, detection coils 12A, 12B are provided beneath the movable plate 5, and a detection current is superimposed on the drive current in the planar coil 7.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: June 16, 1998
    Assignee: The Nippon Signal Co., Ltd
    Inventors: Norihiro Asada, Masayoshi Esashi
  • Patent number: 5763783
    Abstract: The present invention relates to an acceleration sensor which uses magnetic coupling to detect acceleration. A mass portion 3 is movably supported on a frame 2 by means of support beams 4. A first planar coil 5 is disposed on the mass portion 3, and a second planar coil 8 is provided facing the first planar coil 5 with a space therebetween. A transformer is made up with the first planar coil 5 as the primary winding and the second planar coil 8 as the secondary winding. Acceleration is obtained using magnetic coupling to detect the change in the distance between the coils, that is to say, the displacement of the mass portion.
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: June 9, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventor: Norihiro Asada
  • Patent number: 5734269
    Abstract: A bridge circuit monitoring apparatus which can accurately detect a fault in a bridge circuit of a sensor circuit even when multiple faults occur. Changes in the imbalance output signal of a bridge circuit (11) are monitored with a first window comparator (WC1), while changes in the bridge circuit (11) power source current, which does not require amplifying, are monitored with a second window comparator (WC2). At the time of an output of logic value "1" indicating that the monitoring outputs are both normal, an output of logic value "1" indicating that the bridge circuit (11) is normal is generated from an AND gate (13).
    Type: Grant
    Filed: April 5, 1996
    Date of Patent: March 31, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Toshihito Shirai, Hiroji Anzai, Koichi Futsuhara
  • Patent number: 5717302
    Abstract: The invention relates to a motor stopped verification apparatus for verifying if a motor has stopped rotating, and in particular to rotation sensor technology for sampling rotation signals from a motor. With a first aspect of the invention, a high frequency current signal is supplied to the winding of a tachometer generator incorporated in a motor. This high frequency signal is modulated by an output signal from the tachometer generator, and the modulated signal made a motor rotation detection output from a rotation sensor. With a second aspect of the invention, a transducer coil is utilized as a part of an oscillator, and the motor rotation is converted to a change in the oscillation frequency of the oscillator and then sampled. With a third aspect of the invention, the motor rotation is converted by means of a resonance circuit incorporating the transducer coil, into a change in terminal voltage of the resonance circuit and then sampled.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: February 10, 1998
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Toshihito Shirai, Hiroji Anzai, Koichi Futsuhara
  • Patent number: 5703452
    Abstract: A movable section of a machine is enclosed by a fence and a door. A locking device provided on the door is controlled by a movable section control circuit. In the movable section control circuit, an operating switch outputs either a movable section ON signal or a movable section OFF signal. A door switch outputs an ON signal representing that the door is open. A switch means constitutes a self-holding circuit which uses an AND signal constituted of the movable section OFF signal from the operating switch and a rotation stop signal as a reset input signal and an OR signal constituted of an ON signal from the door switch and a rotation-presence signal as trigger signal to provide the locking device with a control signal. When a sensor fails, the locking devive is not unlocked even if the operating switch for driving the movable section is closed.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: December 30, 1997
    Assignee: The Nippon Signal Co., Ltd.
    Inventor: Koichi Futsuhara
  • Patent number: 5675317
    Abstract: A residual pressure sensor for verifying that a residual pressure is zero, and to a monitoring apparatus for monitoring for faults in the residual pressure sensor. In order to detect that a residual pressure has completely gone, the residual pressure sensor detects change conditions in the output therefrom, and an output for no residual pressure is not generated while there are changes. Moreover, an electrical power supply condition to a drive solenoid (21) of a solenoid valve for opening/closing a pressure supply line, is monitored using a fail-safe current sensor (21) which outputs a logic value "0" when the presence of a current is detected, and which outputs a logic value "1" when the presence of a current is not detected. Fault monitoring of the residual pressure sensor is then carried out based on the monitoring output conditions of the current sensor and the output conditions of the residual pressure sensor.
    Type: Grant
    Filed: January 29, 1996
    Date of Patent: October 7, 1997
    Assignees: Nagano Keiki Seisakusho, Ltd., The Nippon Signal Co., Ltd.
    Inventors: Masato Ichikawa, Koichi Futsuhara, Masayoshi Sakai
  • Patent number: 5668706
    Abstract: This invention relates to a load driving circuit having a fail-safe breaking mechanism for breaking a primary power source when a failure occurs. This invention also relates to a load driving circuit capable of saving electricity in driving an inductive load and reducing a delay in stopping the load. The breaking mechanism for braking the primary power source has no contact. The load driving circuit includes a power supply circuit involving a semiconductor switching element that turns ON and OFF the supply of power to the load. There is arranged a detector for detecting a failure in the semiconductor switching element. When detecting a failure, the detector provides an output signal to activate the breaking mechanism. To drive the inductive load, the power supply circuit may have two power supply sources. In response to a load driving instruction signal, the two power supply sources together apply a high voltage to the load.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: September 16, 1997
    Assignee: Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Koichi Futsuhara
  • Patent number: 5666081
    Abstract: The present invention relates to a fail-safe on-delay circuit which uses an an electronic circuit. An input signal higher than a power source potential is input to a PUT oscillating circuit and a pulse signal generated with a predetermined time constant, is once changed in a level conversion circuit to a level within a range of the power source potential, and then is phase inverted and a rising differential signal of the phase inverted signal is formed. The input signal to the PUT oscillation circuit is applied to one input terminal of a fail-safe two input window comparator, and the differential signal is input to the other input terminal, and self held. After a predetermined delay time an output of logic value 1 is generated from the window comparator. As a result a fail-safe on-delay circuit can be made wherein, in the event of a fault in the elements of the circuit the delay time is not shortened.
    Type: Grant
    Filed: November 23, 1994
    Date of Patent: September 9, 1997
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Masayoshi Sakai, Koichi Futsuhara
  • Patent number: 5640006
    Abstract: A multi-axis light beam type sensor with a simple fail-safe sensor system which stops when the sensor system is abnormal (logic value "0") is provided. The construction is such that scanning output signals for synchronously driving respective light emitting elements (LD) and light receiving elements (PD) positioned facing each other are generated using shift registers. A normal or abnormal condition of the scanning output signals is judged based on an output of the light transmission side shift register (5), using an addition operation in a scanning output signal checking circuit (9). Moreover, coincidence or non coincidence of last stage outputs of the respective shift registers of the light transmission and light reception sides, is determined by a coincidence detecting circuit (10).
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 17, 1997
    Assignee: The Nippon Signal Co., Ltd.
    Inventors: Hiroji Anzai, Takashi Sugiyama, Tetsuya Ishioroshi, Masakazu Kato
  • Patent number: 5638043
    Abstract: The present invention relates to a warning apparatus which can continuously monitor a normal condition wherein an alarm sound can be produced. When a high level judgement signal (W) indicating safety is input, an inaudible frequency signal is supplied from a V-F converter (11) to a speaker (13) so that a warning sound of an inaudible frequency is generated, while when a low level (zero) judgement signal (W) indicating danger is input, an audible frequency signal is supplied from the V-F converter (11) to the speaker (13) so that a warning sound of an audible frequency which can be heard by personnel is generated. Furthermore, when an output current of an inaudible frequency or an audible frequency is supplied to the speaker (13), the output current is sampled by a current transformer (21) of a monitoring circuit (20), and amplified and rectified to give a direct current output signal (SN), thereby enabling verification that the warning apparatus is normal.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: June 10, 1997
    Assignee: The Nippon Signal Co., Ltd.,
    Inventors: Masayoshi Sakai, Koichi Futsuhara