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.
Claims19
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 to read the original image, comprising:
- control means for shifting an ON start timing of the light source for illuminating the original image from a start timing of a predetermined charge storage period of the image sensing device,
- wherein said control means controls a phase of a control pulse for driving the light source so as to shift the ON start timing of the light source.
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 to read the original image, comprising:
- control means for shifting an ON start timing of the light source for illuminating the original image from a start timing of a predetermined charge storage period of the image sensing device,
- wherein the light source contains a plurality of color components which have afterglow characteristics different from each other.
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 to read the original image, comprising:
- a control step of shifting an ON start timing of the light source for illuminating the original image from a start timing of a predetermined charge storage period of the image sensing device,
- wherein, in the control step, a phase of a control pulse for driving the light source is controlled so as to shift the ON start timing of the light source.
Dependencies are inferred from the claim text.