| 摘要 |
<p>PURPOSE: To detect approach of a human body surely by varying the oscillation frequency of a resonance circuit based on the variation in the stray capacity at a human body detecting part caused by the approach of a human body thereby employing an inconspicuous detecting part which can be mounted easily on a glass window. CONSTITUTION: A thin film of indium tin oxide is deposited on the surface of a transparent polyester film to obtain a transparent conductor 1 which is interposed between plate glasses 2, 3 to constitute a human body detecting part. A flexible printed wiring board 5 is provided at an end part of the conductor 1 and a coil 6 disposed at the forward end thereof provided a magnetic coupling part along with a coil 7 formed in the resonance circuit of an oscillation circuit built in a slave unit 12. When a human body approaches the conductor 1, stray capacity at a capacitor part provided by the conductor 1 varies to cause variation in the resonance frequency. Consequently, the oscillation frequency of the oscillation circuit is shifted to cause frequency modulation of an output signal from the oscillation circuit. The output signal is delivered to a master unit 20 where it is subjected to FM detection and the approach of human body is decided by a decision circuit.</p> |
