| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanning device capable of easily compensating the abnormality of image forming due to astigmatic aberration in the sub- scanning direction and performing such compensation after the assembling of the device. SOLUTION: In the optical scanning device, a first image forming lens system 2 is provided with two light transmitting plates 71, 72 between a light source 1 and a collimator lens 21. The light transmitting plates 71, 72 are composed of flat plates having equal plate thickness and refractive index and by arranging them so as to incline by the same tilt angle to the exit optical axis in the reverse direction, the deviation of the position of a sub-scanning image surface is compensated by reversely utilizing the astigmatic aberration. A control part 64 controls the drive of a stepping motor 63 based on the spot diameter of a synchronizing signal light beam L4 detected by a light receiving device 62 and adjusts the tilt angles of the light transmitting plates 71, 72. |
