ORIGINAL READING DEVICE

摘要

PURPOSE:To realize the accurate reading scan by comparing the output of a photoelectric converting element with a reference level via a comparator before an original reading job is started, and confirming that the prescribed output is obtained. CONSTITUTION:The tube wall temperature of a fluorescent lamp 2 is detected by a temperature detecting element 6 and the energization of a heating element 7 is controlled so that the lamp 2 is kept at a prescribed temperature. A read control means 18 turns on the lamp 2 with a start signal for illumination of a white reference surface and also sets a timer 11. The electric signals undergone the photoelectric conversion via a line sensor 4 are supplied to a comparator 10 and a signal processing part 200 via an amplifier 8. The comparator 10 compares the output of the amplifier 8 with a reference level and delivers '1' to the means 18 if all bits of a single line are higher than the reference level. Thus the means 18 delivers a read start signal to a gate circuit 13 of the part 200 to delete the gate.