Canon Kabushiki Kaisha

Noriko Takeuchi

Yasuhiro Aoyama

An object of the present invention is to detect the home position with a high accuracy without being affected by temperature. The present invention is an image reading apparatus having a reading portion, and the apparatus includes: an acquisition unit configured to acquire first data obtained by the reading portion reading a main scanning line in a state where a light source of the reading portion is turned on in a first light quantity, and second data obtained by the reading portion reading the main scanning line in a state where the light source of the reading portion is turned on in a second light quantity smaller than the first light quantity; a generation unit configured to generate difference data by subtracting the value of the second data from the value of the first data; and a determination unit configured to determine whether a mark arranged at a position corresponding to a home position of the reading portion has been detected on the main scanning line based on the difference data.

Image reading apparatus, image reading method, and storage medium

This invention is directed to image reading capable of suppressing EMI unwanted radiation while maintaining image quality. To accomplish this, the following processing is executed when reading an original image by a photoelectric transducer. More specifically, a first driving signal where SSCG spread modulation is applied, and a second driving signal where no SSCG spread modulation is applied are generated from a reference signal. Either the first or second driving signal is selected, and a timing signal for reading the original image is generated based on the selected driving signal. The image signal obtained by the photoelectric transducer is latched using the timing signal. The latched image signal is transferred for subsequent image processing. Upon reading a one-line image original, the second driving signal is selected till the completion of the latch operation, and after the latch operation, the first driving signal is selected for an image signal transfer operation.

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Tokyo, Japan

Noriko Takeuchi