| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide medium detector which operates with reduced power consumption. SOLUTION: A power source voltage requesting signal generating part 3 for transmitting the power source voltage requesting signal at a specified period is provided on a CPU 2, and an NPN transistor 6 and a PNP transistor 8 which can impress power source voltage on a photo-microsensor 15 from a power source part 9 only when the power source voltage requesting signal is received, are arranged among the CPU 2, the power source part 9 and the photo-microsensor 15. By this arrangement, the power source voltage is impressed on the medium detecting part only when the power source voltage requesting signal is generated, therefore, the power consumption is reduced than in the conventional practice by the amount for the time during the voltage is not impressed.</p> |
