| 摘要 |
PURPOSE:To fix the integration value of a detection signal from an image sensor by setting up the brightness of a light emitting element and time required for lighting up a light emitting element based upon the detection signal. CONSTITUTION:A lighting time adjusting signal A for lighting up LED arrays 10A, 10B is outputted and a brightness adjusting signal B for adjusting the brightness of the LED arrays 10A, 10B is outputted based upon a moving speed measured by the image sensor 12. The LED arrays 10A, 10B are controlled by the signal B so that the brightness is reduced when the moving speed of the sensor 12 is slow or increased at a high moving speed. Thus, the integration value of a detection signal read out by the image sensor 12 can be fixed. |
