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US 2003/0156183 A1Published application
Multi-beam optical scanning device, and image forming apparatus and color image forming apparatus using the same
AssigneeCanon Kabushiki Kaisha
InventorKeiichiro Ishihara
Life of this patent
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Abstract
A multi-beams optical scanning device is constituted such that a width in a main scanning direction of each of a plurality of light beams emitted from a light source unit is wider than a moving area in the main scanning direction in which a deflection facet of a deflection unit can move and exist when the plurality of light beams emitted from the light source unit are deflected toward an entire effective scanning area on the surface to be scanned and are deflected toward the synchronous detection means provided outside the effective scanning area.
Claims30
A multi-beam optical scanning device comprising:
- light source means having a plurality of light emitting points spaced apart at least in a main scanning direction;
- deflection means for deflecting a plurality of light beams emitted from the light source means;
- a scanning optical system for focusing the plurality of light beams deflected by the deflection means on a surface to be scanned;
- and
- synchronous detection means for detecting timing at which the plurality of light beams start scanning in an effective scanning area on the surface to be scanned,
- wherein a width in the main scanning direction of each of the plurality of light beams emitted from the light source means is wider than a moving area in the main scanning direction in which a deflection facet of the deflection means can move and exist when the plurality of light beams emitted from the light source means are deflected toward the entire effective scanning area on the surface to be scanned and are deflected toward the synchronous detection means provided outside the effective scanning area.
3 more elements
A multi-beam optical scanning device comprising:
- light source means having a plurality of light emitting points spaced apart at least in a main scanning direction;
- deflection means for deflecting a plurality of light beams emitted from the light source means;
- and
- a scanning optical system for focusing the plurality of light beams deflected by the deflection means on a surface to be scanned,
- wherein a width in the main scanning direction of each of the plurality of light beams emitted from the light source means is wider than a width in the main scanning direction of a deflection facet of the deflection means, and
- wherein, when an angle defined in the main scanning direction by principal rays of the plurality of light beams emitted from the light source means when the plurality of light beams are incident on the deflection means is assumed to be Δ (rad), a distance from the deflection facet of the deflection means to a rotation center of the deflection means is assumed to be Ldef (mm), a focal length in the main scanning direction of the scanning optical system is assumed to be fk (mm), an angle defined in the main scanning direction between an optical axis of an incident optical system and an optical axis of the scanning optical system is assumed to be Q (rad), and a field angle defined between the principal ray of light beam deflected by the deflection facet and the optical axis of the scanning optical system is assumed to be θ (rad), a condition of the following expression is satisfied:
- {(α×Ldef)/(2×fk)}×{cos(Q/2)−sin(Q/2)×tanθ}≦0.014.
4 more elements
A multi-beam optical scanning device comprising:
- light source means having a plurality of light emitting points spaced apart at least in a main scanning direction;
- deflection means for deflecting a plurality of light beams emitted from the light source means;
- and
- a scanning optical system for focusing the plurality of light beams deflected by the deflection means on a surface to be scanned,
- wherein a width in the main scanning direction of each of the plurality of light beams emitted from the light source means is wider than a width in the main scanning direction of a deflection facet of the deflection means, and
- wherein, when an angle defined in the main scanning direction by principal rays of the plurality of light beams emitted from the light source means when the plurality of light beams are incident on the deflection means is assumed to be a (rad), a distance from the deflection facet of the deflection means to a rotation center of the deflection means is assumed to be Ldef (mm), and a focal length in the main scanning direction of the scanning optical system is assumed to be fk (mm), a condition of the following expression is satisfied:
- (α×Ldef)/(2×fk)≦0.014.
4 more elements
Dependencies are inferred from the claim text.