| 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 measuring the emission time of a laser beam in accordance with a picture signal and sending a prescribed signal when the contents of a storage means exceed a preliminarily set reference value. CONSTITUTION:A picture signal fv inputted to an image memory device is modulated by a modulator 1 and is amplified to a laser input voltage, and the emission power of a laser 2 is changed in accordance with the amplified signal. Meanwhile, a counter 3 integrates and counts the light emission time of the laser 2 from the output of the modulator 1, and the counter output is corrected in accordance with the laser light emission power by a correcting circuit 5 and is integrated and stored in a memory 6. A comparator 7 compares a value (x) stored in the memory 6 with the preliminarily set reference value; and if the value (x) is equal to or larger than the reference value (y), a signal is outputted to a controller 8, and a toner replenishing signal S indicating toner replenishment or cartridge replacement is sent to a display means. When the toner is replenished or a cartridge is replaced, the memory 6 is reset. Thus, white omission due to lack of the toner and the solidification or melt-fixing of the toner due to excess replenishment are prevented. |
