| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve a problem in which: in a laser beam emitting device that separates a part of laser beam emitted from a semiconductor laser to a photoreceptor with a half mirror, guides the separated laser beam to an optical sensor to detect the amount of light, and controls the amount of light on the basis of the detection result, the amount of the laser beam, which has been reflected on an inner surface of a lens barrel part, entering the optical sensor varies as an FFP of the laser beam varies, which prevents accurate control of the amount of light. <P>SOLUTION: A first diaphragm is provided between a semiconductor laser and a half mirror, and a second diaphragm is provided between the half mirror and an optical sensor. <P>COPYRIGHT: (C)2013,JPO&INPIT |
