| 摘要 |
PURPOSE:To perform secure detection without any dead area by storing the output level of an infrared sensor in a waveform storage means as a normal level waveform throughout one scan on a scanning pattern. CONSTITUTION:When a positive-directional rotary driving signal sent out of a microcomputer 17 is sent to a stepping motor driving circuit 22, a stepping motor 13 rotates in a positive direction by the specific angle of rotation. Then when the motor 13, i.e. a sensor body 12 rotates by 2 deg. at every time, a digital detection signal from an A/D converter 21 is fetched and stored in the Nth memory address of a memory circuit 24. Thus, the digital detection signal is fetched at every time a main body 12 rotates by 2 deg.. When the main body 12 rotates by 360 deg., the microcomputer 17 sends out a reverse rotation signal next and when the main body 12 reverses by 2 deg., the digital detection signal is fetched. Then, the signal level stored in the Nth memory space is read out by the microcomputer 17 and compared with a currently fetched detection signal level, thereby sending out an alarm driving signal to an alarm device 23 when those signal levels coincide with each other. |
