| 摘要 |
PROBLEM TO BE SOLVED: To realize image forming with high image quality stably by stably adjusting a pulse width modulation circuit automatically. SOLUTION: After a digital image signal IDATA is once converted into an analog image signal, the converted signal is compared with a reference wave signal with a prescribed period to scan a laser beam subjected to pulse width modulation onto an image forming body thereby conducting gradation reproduction. The device is provided with an automatic proofreading circuit 210 generating a calibration signal CAL synchronously with a dot clock signal DCK and with a pulse width modulation section 220 adjusting automatically the input output characteristic by the calibration signal CAL generated by the automatic proofreading circuit 210. |
