| 摘要 |
<p>PURPOSE:To eliminate the malfunction of a magnetic tape detector which detects the transparent leader tape of magnetic tape optically. CONSTITUTION:A look-up table on which data showing a solar light intensity corresponding to used area and time are recorded, is stored in a memory 4. A CPU 3 refers to the look-up table in accordance with a time signal from a clock circuit 1 for the solar light intensity at that time and restricts the light emission of the light emitting unit 12 through a light emission varying unit 10 in accordance with the solar light intensity. With this constitution, such a malfunction that a photodetector unit detects the solar light mistakenly when the solar light intensity is high, can be avoided.</p> |
