| 摘要 |
<p>In a laser beam printer for scanning a surface of a uniformly charged photoconductive photosensitive drum (8) by a laser beam to form an electrostatic latent image and developing the electrostatic latent image by fine particles of toner, a dust-proof box (26) is provided at a laser beam emitting port of an exposure optical system (4) to prevent the toner from entering into the exposure optical system and contaminating the same.</p> |
