| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for collimating a transmission/reception part by using an annunciation lamp, in a crime-prevention system in which the transmission/reception part is integrally formed. SOLUTION: In a transistor T of the transmission part, by the control of a "microcomputer 40", a collector current passes through a collector resistance Cb of the transistor T. Infrared rays A are emitted by an LED (sign La) of the transmission part side due to the current. The emitted infrared rays A are received by a light receiving element P (phototransistor) of the reception part side. A light receiving signal (reception output) is fed trough a "filter" (denoising band pass filter) to eliminate noise, is then "amplified", and is further subjected to comparison measurement by a "comparator", and then information thereon is sent to the "microcomputer 40". The information is subjected to "recognition of level thereof", and "decision of detection level" (collation between the recognized level and a predetermined level) is performed. By the annunciation lamp 13, "indication" of each detection level is displayed. COPYRIGHT: (C)2005,JPO&NCIPI
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