Canon Kabushiki Kaisha

Satoru Kijima

Toshio Hayashi

Noriaki Matsui

Katsuhiro Ishido

Nobuo Matsuoka

Tsunao Honbo

Takeshi Aoyama

Hiroaki Takeda

Masahiro Kurahashi

Satoru Kanno

Masayoshi Taira

Takeharu Uchizono

Shigeo Aoyagi

Hideaki Chishima

Akihiro Kashiwabara

Junichi Kishimoto

In an image reading apparatus having a light source for illuminating a document, an image sensing element for outputting an electrical signal in accordance with an input light quantity, a first reference member, and a second reference member, shading correction data is acquired. A time since the light source is turned on is measured, and when the measured time does not reach a predetermined time, shading correction data is acquired by a first method using the first reference member. When the predetermined time has elapsed, shading correction data is acquired by a second method using the second reference member.

Image reading apparatus, composite apparatus using the image reading apparatus, and control apparatus and method for the image reading apparatus

An original size sensing method for an apparatus which includes a photoelectric converter for reading an image of an original placed on a platen, and a light source for irradiating the original with light, determines the presence/absence of incidence of ambient light on the basis of an output from the photoelectric converter while the light source is kept off. When ambient light is found to be incident, the method determines the size of an original placed on the platen on the basis of that output from the photoelectric converter, which falls outside the range in which the ambient light is incident, while the light source is kept on.

Sensing of original size

Shading correction data used in an image reading apparatus for shading-correcting image data obtained by reading an original image by a line sensor is acquired. A defect position on a white reference plate and a defect correction coefficient for correcting shading correction data at this defect position are obtained, and the shading correction data at the defect position is corrected by using the defect correction coefficient. Shading correction is performed by using the corrected shading correction data.

Image reading apparatus and shading correction data acquiring method

An image processing apparatus structured by combining an image reading apparatus and an image formation apparatus with each other enables a user to freely combine these apparatuses without considering the sum of power consumption of the image reading apparatus and power consumption of the image formation apparatus. When the sum of power consumption of a reader unit and power consumption of a printer unit exceeds, e.g., 1.5 kW, the reader unit is set to be in a low power consumption mode such that the sum of power consumption becomes equal to or smaller than 1.5 kW. Even when the low power consumption mode of the least power consumption quantity is selected and the sum of power consumption still exceeds 1.5 kW, use of the apparatus is inhibited and the inhibition is displayed.

Image processing apparatus, image reading apparatus, image formation apparatus, control method thereof, and storage medium

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Chiba, Japan

Satoru Kijima