Optical scanning device, method of adjusting optical scanning device, and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorsMitsuo Suzuki, Kohji Sakai
Life of this patent
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Abstract
An optical scanning device includes: 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; and 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.
Claims7
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.
A light-amount adjusting method of an optical scanning device that includes a light source emitting a laser beam modulated and driven according to an image forming signal, and a scanning optical system including a polygon mirror to scan a surface of a photoconductor with a laser beam from the light source, the method comprising:
- associating a sub-scanning position by the polygon mirror with each surface of the polygon mirror;
- adjusting a light amount of the light source according to the sub-scanning position for each surface of the polygon mirror;
- storing 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
- counting a number of the sub-scanning position groups for which grouping has been performed;
- adjusting a light amount of the light source according to the sub-scanning position group;
- and
- adjusting the light amount of the light source only when the number of the sub-scanning position groups is two or more.
A light-amount adjusting method of an optical scanning device that includes a light source emitting a laser beam modulated and driven according to an image forming signal, and a scanning optical system including a polygon mirror to scan a surface of a photoconductor with a laser beam from the light source, the method comprising:
- detecting sub-scanning positions by the polygon mirror;
- associating the sub-scanning positions detected at the detecting with respective surfaces of the polygon mirror;
- storing detected sub-scanning positions of the respective surfaces of the polygon mirror by grouping detected sub-scanning positions falling within predetermined position ranges into sub-scanning position groups;
- and
- adjusting a light amount of the light source for each surface of the polygon mirror according to the sub-scanning position groups.
Dependencies are inferred from the claim text.