| 摘要 |
PURPOSE:To monitor the degree of variation of photoreceptor characteristics by providing a light source for irradiating a part of a photoreceptor with light after an electrostatic latent image is developed and a photosensor which receives the reflected light of the irradiation light and detects the quantity of the light. CONSTITUTION:A light beam from a laser tube 10 is modulated 22 on the basis of image information VD and passed through the optical system consisting of a lens LS and mirrors M1 and M2, a rotating polygon mirror 30, and a dimmer 40 to develop the electrostatic latent image on a photosensitive drum DR. The part of the surface developed by a developing device 50 is irradiated with light from the light source 60 and its reflected light is received by the photosensor 70 and the drive level of a modulator driver 21, i.e. the quantity of the laser beam modulated optically by the modulator 22 is controlled on the basis of the detection output of the photosensor 70. |
