| 摘要 |
PURPOSE:To detect the rise of a scanner motor without deterioration of a laser and a photoreceptor drum by a method wherein a laser light control means makes a laser light be generated periodically for a prescribed time from the time of starting of the scanner motor and the rise till a prescribed number of revolutions are reached is detected from a horizontal sync signal. CONSTITUTION:CPU 10 makes a scanner motor 3 rotate when image data are inputted from outside. The CPU 10 makes a laser 1 emit a light only for a prescribed time from the time of starting of the scanner motor 3 and monitors the period of a horizontal sync signal 7 at that time given by a laser light position detector 5. When the period of the horizontal sync signal 7 is slower than the period at the steady number of revolutions of the scanner motor 3, the scanner motor 3 is judged not to have risen and emission of the laser is stopped. After a certain time, the emission of the laser is conducted again for the prescribed time and the period of the horizontal sync signal is monitored likewise. These operations are repeated until the period of the signal becomes equal to that at the time of the steady revolution, and the motor is judged to have risen at the stage at which the equality is attained. |
