| 摘要 |
PURPOSE:To accurately process a minute signal by providing a suppressing part through which a voltage supply part supplies the power with reduction of the voltage level or supplies no power to a load part when a signal processing part processes the minute signal. CONSTITUTION:The distance from a screen 16 is measured at first when a focusing operation is desired after a halogen lamp 11 is turned on with push of a switch 7. Under such a condition a suppressing part 12 functions to supply the power with reduction of the voltage level or no power to the lamp 11 from a power supply 9. In other words, the lamp 11 is dimmed out or turned off in order to prevent the mixture of noise of the lamp 11 before a signal reflected wave is supplied from the screen 16. If the mixture of noise occurs, a signal processing part 10 has a malfunction when deciding the distance. Thus the influence of a noise source can be eliminated. |
