| 摘要 |
PURPOSE:To maintain range finding accuracy by operating a range finding circuit with a current supplied from a voltage holding capacitor in a period when a switch circuit is opened. CONSTITUTION:The switch circuit Q1 is inserted between the range finding circuit 14 and a power source battery 11, and also, the voltage holding capacitor C1 is connected in parallel with the power source input terminals 14P, 14M of the range finding circuit 14. And the device is comprised in such a way that the range finding circuit 14 is disconnected from the power source battery 11 in the period when the terminal voltage of the power source battery 11 is decreased by the emission of a light emitting element D1, and the range finding circuit 14 is operated with the current supplied from the voltage holding capacitor C1. Therefore, the change of the voltage supplied to the range finding circuit 14 can be suppressed even when a capacitor small in capacity is employed as the voltage holding capacitor 1. In such a manner, the range finding accuracy can be secured. |
