| 摘要 |
PURPOSE:To reduce a package space by using power transistors(TR) which constitute a bridge circuit for supplying electric power to a motor in common as switching elements which control the light emission of a light emitting element for distance measurement. CONSTITUTION:The motor M performs the specific operation of the camera and the bridge circuit which supplies the electric power to the motor M consists of power transistors(TR) Qc - Qf. In this case, the light emitting element IREDa for distance measurement is connected to the power TRs Qc and Qe and a light emitting element IREDb is connected to the power TRs Qd and Qf. Then the cathodes of the light emitting elements IREDa and IREDb are connected to the collector of the power TR Qa in common for light emission control. Consequently, the bridge circuit for the motor is used in common to drive the light emitting elements, and then only substantially one power TR is required for the light emission part of the range finder, thereby reducing the package space. |
