Image reading apparatus, and dimming control method and line sensor layout method therefor
AssigneeCanon Kabushiki Kaisha
InventorsHiroshi Sato, Hiroyoshi Maruyama, Ken Tanabe, Masashi Minami, Shigeo Yamagata, Mitsuru Kurita, Koji Arai, Tsutomu Utagawa, Koichi Ishimoto
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Abstract
In an image reading apparatus for reading an original image using a light source containing a plurality of color components, a control pulse for dimming the light source is generated by pulse-width modulation symmetrically with respect to a reference timing (for example, the central position in one storage time or the storage start timing) in one predetermined storage time of a line sensor.
Claims22
An image reading apparatus for irradiating an original image with a light source and forming an image corresponding to the original image on an image sensing device through an imaging optical system while scanning the original image in main and sub-scanning directions so as to read the original image, comprising:
- control means for reducing barycenter movement of read positions of a plurality of color components in the sub-scanning direction, that is generated by afterglow characteristics of the plurality of color components contained in the light source for illuminating the original image.
A dimming control method for a light source in an image reading apparatus for irradiating an original image with the light source and forming an image corresponding to the original image on an image sensing device through an imaging optical system while scanning the original image in main and sub-scanning directions so as to read the original image, comprising:
- a control step of reducing barycenter movement of read positions of a plurality of color components in the sub-scanning direction, that is generated by afterglow characteristics of the plurality of color components contained in the light source for illuminating the original image.
Dependencies are inferred from the claim text.