Method and apparatus for inspecting scanning beam of scanning optical system

摘要

A scanning optical system manufacturing method includes receiving a scanning beam, emitted from a scanning unit including an incident optical system and a deflecting device and passed through an image-forming optical system, in an area having a width in the main scanning direction narrower than a spot diameter of the scanning beam by a light-receiving unit configured to be capable of being displaced at each image height position in the main scanning direction, calculating, based on an output of the light-receiving unit, a peak light quantity at each image height position of the scanning beam, smoothing distribution data of the peak light quantity at each of the image height position acquired by the calculating, and determining, based on the data acquired by the smoothing, either nondefective/defective states of the scanning unit and the image-forming optical system or a nondefective/defective state of only the image-forming optical system.

主权项

1. A scanning optical system manufacturing method comprising:
receiving a scanning beam, emitted from a scanning unit including an incident optical system and a deflecting device and passed through an image-forming optical system, in an area having a light-receiving width in a main scanning direction narrower than a spot diameter of the scanning beam by a light-receiving unit configured to be capable of being displaced at each image height position in the main scanning direction; calculating, based on an output of the light-receiving unit, a peak light quantity at each image height position of the scanning beam; smoothing, using an evaluation width in the main scanning direction, distribution data of the peak light quantity at each image height position acquired by the calculating; and determining, based on the data acquired by the smoothing, either nondefective/defective states of the scanning unit and the image-forming optical system or a nondefective/defective state of only the image-forming optical system, wherein the evaluation width is equal to or less than a shift amount of the scanning beam on an image surface of the image-forming optical system in the main scanning direction when the scanning beam from the deflecting device shifted as much as a width of the scanning beam at an optical surface of the image-forming optical system in the main scanning direction.