| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption by turning off a display part when a stationary VCR(video cassette recorder) is set in a standby state. SOLUTION: When infrared rays from a user 11 are detected by a pyroelectric element 12, a minute voltage is generated. The minute voltage is supplied to an amplifier 13 from the element 12. Then, the supplied minute voltage is amplified by the factor of about 1600 with the amplifier 13 and compared with a reference voltage source 15 by a comparator 14. When it is judged that the user 11 exists, a pulse is generated from the comparator 14 and a control signal is supplied to switches 17 and 18 in a timer 16 by regarding the pulse as a trigger. The switches 17 and 18 are turned on according to the control signal and turned off according to the control signal after a prescribed time (several minutes) elapses. Then, the display part 19 is turned on/off according as the switches 17 and 18 are turned on/off. |
