| 摘要 |
<p>The means enables a signal transmitted by the clock to be interrupted or else finally turned off by the user approaching the clock, or else moving only a part of his body, for example his hand towards it. The clock is preferably equipped with a transmitter 2, 2' emitting infrared radiation or ultrasonic waves and a corresponding receiver 3, 3' which detects infrared radiation or the ultrasonic waves reflected by the moved body part 1. The temporal change in intensity is determined in a signal-conditioning circuit 4, 5 and 6 and compared in a threshold switching stage 7 to a prescribable value upon the overshooting of which the alarm signal A is turned off. …<IMAGE>… </p> |
