| 摘要 |
PURPOSE:To reduce the power consumption by controlling an electric power supplied to a light emitting element. CONSTITUTION:A latching circuit 103 is a circuit for receiving a light emitting timing of a light emitting element 104 by a driver driving signal 202, latching a detecting signal 204 of a photodetector 105 when the light emitting element is emitting a light, and sending out its latch output signal 206. This latching circuit 103 inputs, for instance, a driver driving signal 202, and it is constituted of a delaying circuit 301 having a shorter delay time than that of a delaying circuit 101, and a holding circuit for holding the detecting signal 204 of the photodetector by receiving a delay output signal 205 of the delaying circuit 301. |
