| 摘要 |
PROBLEM TO BE SOLVED: To make an optical scanning device low in cost by covering all surroundings of a light deflector with light transmissive resin and integrally providing a first image forming optical system, the first image forming optical system and the one part of a second image forming optical system, or the one part of the second image forming optical system on the transmissive resin to reduce the noise of the light deflector, thereby preventing the surfaces of the light deflector from being soiled and reducing the number of components. SOLUTION: A first image forming optical system 24 is integrally provided on the cover 36 of light transmissive resin. Sine this cover 36 is made so as to cover the whole of a polygon mirror 25, it reduces the leaking of the wind cutting sound to be generated by the mirror 25 to the outside. Moreover, since dust is reduced in the inside of the cover 36 and the inside of the cover is filled with gas made to be low humidity (nitrogen gas, etc.), surface of reflection areas 26 of the polygon mirror 25 are made not to be polluted. Moreover, surfaces of the transmission part (the first image forming optical system 24) of the optical flux from a light source 23 and of a part through which the reflected light beam by the polygon mirror 25 transmits are worked with the accuracy of optical grade. |
