Patent ID: 9557563
Date: 2017-01-31
CPC Classifications: B41J,G02B,G03G

Claim:
1. An optical scanning device comprising: a light source that emits a laser beam modulated and driven according to an image forming signal; a scanning optical system that includes a polygon mirror to scan a surface of a photoconductor with the laser beam from the light source; a surface identifying unit that associates a sub-scanning position by the polygon mirror with each surface of the polygon mirror; a light-amount adjusting unit that adjusts a light amount of the light source according to the sub-scanning position for each surface of the polygon mirror; a sub-scanning-position-group storage unit that stores a sub-scanning position for each surface of the polygon mirror as a sub-scanning position group in which sub-scanning positions of respective surfaces of the polygon mirror are grouped into a range of sub-scanning positions set in advance; and a counter that counts a number of the sub-scanning position groups for which grouping has been performed, wherein the light-amount adjusting unit adjusts a light amount of the light source according to the sub-scanning position group, and only when the number of the sub-scanning position groups is two or more, the light amount of the light source is adjusted by the light-source adjusting unit.