Exposure apparatus and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorDaisuke Akagi
Life of this patent
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Abstract
An exposure apparatus according to one aspect of this invention includes a plurality of laser light sources (LDs) each configured to output a laser beam of a light power corresponding to a supplied current. The exposure apparatus exposes the surface of a photosensitive drum with a plurality of laser beams. When determining the incident states of the laser beams on the light-receiving surface of a PD, a CPU controls at least one LD as a control target. The CPU causes the control target LD by a current of a predetermined magnitude to emit light and output a laser beam. Based on a light power detection value from the PD for a laser beam output from the control target LD, the CPU determines the incident state of the laser beam on the light-receiving surface of the PD.
Claims15
An exposure apparatus which exposes a surface of a photosensitive member with a plurality of laser beams, comprising:
- a plurality of laser light sources each configured to output a laser beam of a light power corresponding to a supplied current;
- a beam splitter configured to split each of the plurality of laser beams emitted by the plurality of laser light sources;
- an optical member configured to guide one laser beam split by the beam splitter to the photosensitive member for each of the plurality of laser beams;
- a light-receiving unit configured to receive another laser beam split by the beam splitter for each of the plurality of laser beams;
- a light power detection unit configured to detect a light power of the laser beam entering the light-receiving unit;
- an light emission control unit configured to control, as a control target, at least one laser light source among the plurality of laser light sources, the emission control unit supplying a current of a predetermined value to cause the laser light source serving as the control target to emit light and output a laser beam;
- and
- a determination unit configured to determine an incident state of the laser beam on the light-receiving unit, based on a result of comparison between the predetermined current value and a light power detection value from the light power detection unit for the laser beam output from the laser light source serving as the control target by the emission control unit.
An image forming apparatus including a photosensitive member, comprising:
- a charging unit configured to charge a surface of the photosensitive member;
- an exposure apparatus configured to expose the surface of the photosensitive member with a plurality of laser beams output from a plurality of laser light sources;
- and
- a developing unit configured to develop an electrostatic latent image formed on the surface of the photosensitive member by exposure by the exposure apparatus, and form, on the surface of the photosensitive member, an image to be transferred to a printing medium,
- wherein the exposure apparatus includes:
- the plurality of laser light sources each configured to output a laser beam of a light power corresponding to a supplied current;
- a beam splitter configured to split each of the plurality of laser beams emitted by the plurality of laser light sources;
- an optical member configured to guide one laser beam split by the beam splitter to the photosensitive member for each of the plurality of laser beams;
- a light-receiving unit configured to receive another laser beam split by the beam splitter for each of the plurality of laser beams;
- a light power detection unit configured to detect a light power of the laser beam entering the light-receiving unit;
- an emission control unit configured to control, as a control target, at least one laser light source among the plurality of laser light sources, the emission control unit supplying a current of a predetermined value to cause the laser light source serving as the control target to emit light and output a laser beam;
- and
- a determination unit configured to determine an incident state of the laser beam on the light-receiving unit, based on a result of comparison between the predetermined current value and a light power detection value from the light power detection unit for the laser beam output from the laser light source serving as the control target by the emission control unit.
Dependencies are inferred from the claim text.