| 摘要 |
PURPOSE:To keep intensity of illumination almost constant at the irradiated plane after the start of light source illumination, by changing voltage, current or duty ratio of pulse applied to the light source with the time. CONSTITUTION:A data charging a power supply voltage with time is stored in a memory 8. When an original is detected and a clock pulse generating section 9 is operated, a CPU 10 reads out a data D1 from the memory 8. The data D1 is converted from a power supply voltage Vs to V1 via a D/A conveter 11 and a buffer 12 to drive a light emitting diode 1. Similarly, data D2-Dn are read out from the memory 8 at each specified time and they are converted into power supply voltages V2-Vn corresponding to the data D2-Dn to drive a light emitting diode 1. |
