| 摘要 |
PURPOSE:To prevent the white omission of an image and the solidification or melt-fixing of a toner in a developing device by counting the emission time of a laser beam while correcting it in accordance with the printing rate and integrating and storing the counted value and sending a prescribed signal if stored contents exceed a preliminarily set reference value. CONSTITUTION:A counter 8 counts the laser light emission time, and a modulator 5 reads out successively the printing rates of individual sections to output a signal which switches the value of one count of a counter 8, and the counted value of the counter 8 is integrated successively and stored in a memory 9. A comparator 10 compares always the stored value of the memory 9 and sends a signal to a controller 11 if the stored value exceeds a preliminarily set level, and the controller 11 sends a reset signal RST1 to memories 2 and 3 to reset their contents at every time when one recording paper is printed. When the toner is replenished or a cartridge is replaced, the controller 11 outputs a reset signal RST2 to the memory 9 to reset its contents. Thus, white omission due to lack of the toner and the solidification or melt-fixing of the toner due to excess replenishment are prevented. |
