Image reading apparatus

Abstract

An image reading apparatus includes: a shading roller that has a columnar shape extending in a longitudinal direction and is rotatable about a rotation axis extending in the longitudinal direction, the shading roller including, on an outer peripheral surface, a first white reference arc surface which is white, has an arc-shaped cross section in a lateral direction, and extends in the longitudinal direction, and a groove portion which is located at a position preceding the first white reference arc surface in a rotation direction of the shading roller and extends in the longitudinal direction; an image sensor array that is provided above the shading roller to oppose the shading roller across a transport path of a document, and includes a plurality of image sensors arranged in a main scanning direction and receiving reflected light of light emitted from a light source toward the document or the shading roller; and a processor, wherein the processor acquires shading data based on first arc surface read data indicating pixel values output from the image sensors, respectively, and obtained as the image sensor array receives the reflected light from the first white reference arc surface, corrects document read data, obtained as the image sensor array receives the reflected light from the document, based on the shading data to acquire corrected document read data, and forms image data corresponding to the document based on the corrected document read data.

Dependencies are inferred from the claim text.