PROXIMITY SWITCH
First Claim
1. A proximity switch comprising an actuator unit to be attached to an object, and a sensor unit for detecting the actuator unit without contact and for outputting a signal indicating said detection, the actuator unit comprising a first antenna coil, and the sensor unit comprising a second antenna coil;
- whereinthe sensor unit comprises a transmitting circuit for driving the second antenna coil to transmit an electromagnetic wave at constant frequency and a receiving circuit for detecting an external signal from the second antenna coil;
the actuator unit comprises a power supply circuit that rectifies a signal from the first antenna coil to produce power, and a signal processing circuit for frequency-dividing a signal received by the first antenna coil circuit and transmitting the frequency-divided signal from the first antenna coil are connected to the first antenna coil; and
the sensor unit comprises a control circuit with a memory for registering frequencies of signals transmitted from the actuator unit, the control circuit checking a received signal from the receiving circuit with operation of the transmitting circuit and the frequencies registered in the memory while controlling the operation of the transmitting circuit to determine proximity of the actuator unit to the sensor unit.
1 Assignment
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Accused Products
Abstract
Disclosed is a proximity switch provided with an actuator unit and a sensor unit. The sensor unit is provided with an antenna coil, a transmitting circuit which transmits electromagnetic waves at a constant frequency to the antenna coil, a receiving circuit which detects external signals received by means of the antenna coil, and control circuits. The actuator unit is provided with an antenna coil, a power supply circuit which rectifies an electromotive force generated in the antenna coil, and a signal processing circuit which receives power supply from the power supply circuit, performs frequency-dividing to the signals received by means of the antenna coil, and transmits the signals from the antenna coil after the frequency-dividing. The control circuit of the sensor unit has memory for registering the frequency of the signals transmitted from the actuator unit. The control circuit determines whether the actuator unit is in proximity to the sensor unit or not by checking the received signals detected by means of the receiving circuit with the operations of the transmitting circuit and the frequency registered in the memory.
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Citations
12 Claims
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1. A proximity switch comprising an actuator unit to be attached to an object, and a sensor unit for detecting the actuator unit without contact and for outputting a signal indicating said detection, the actuator unit comprising a first antenna coil, and the sensor unit comprising a second antenna coil;
- wherein
the sensor unit comprises a transmitting circuit for driving the second antenna coil to transmit an electromagnetic wave at constant frequency and a receiving circuit for detecting an external signal from the second antenna coil; the actuator unit comprises a power supply circuit that rectifies a signal from the first antenna coil to produce power, and a signal processing circuit for frequency-dividing a signal received by the first antenna coil circuit and transmitting the frequency-divided signal from the first antenna coil are connected to the first antenna coil; and the sensor unit comprises a control circuit with a memory for registering frequencies of signals transmitted from the actuator unit, the control circuit checking a received signal from the receiving circuit with operation of the transmitting circuit and the frequencies registered in the memory while controlling the operation of the transmitting circuit to determine proximity of the actuator unit to the sensor unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- wherein
Specification