| 摘要 |
PROBLEM TO BE SOLVED: To obtain a laser beam scanning optical device permitting to precisely detect a deviation of the laser beam scanning position at low cost by a simple signal processing. SOLUTION: This laser beam scanning device is mainly composed of a laser diode 2, polygon mirror 6, and fθlens 7, and prints a picture on a photoreceptor drum 101. A scanning position detector 10 is arranged in the neighborhood of an almost optically equivalent position on a surface of the photoreceptor 101. This detector 10 is composed of a first filter 11 having a space grating parallel to the laser beam scanning direction b, a second filter 12 having a space grating tilted at a small angle to the laser beam scanning direction b, cylindrical lens 13, 14 composing a small optical system 14, and a photoelectric converter element 15 receiving the laser beam transmitted through the filters 11, 12.
|
