Image reading apparatus, and image forming apparatus

摘要

Provided is an image reading apparatus including a light source that irradiates an original document that passes through a reading position with light, a light receiving unit that receives reflected light from the original document, a background member that is inclined at an angle where a difference between an incident angle of the light from the light source and a reflection angle of the light to the light receiving unit is smaller than a difference therebetween on the original document present at the reading position, with the original document at the reading position interposed between the background member and the light source, and a foreign substance detecting section that detects, when the original document is not present at the reading position, a foreign substance present at the reading position.

主权项

1. An image reading apparatus comprising:
a light source that irradiates an original document that passes through a reading position with light; a light receiving unit that receives reflected light from the original document; a background member that is inclined at an angle such that there is: (i) a first difference between a first incident angle of light incident on the background member from the light source and a first reflection angle of light reflected from the background member to the light receiving unit when the original document is not present at the reading position, (ii) a second difference between a second incident angle of light incident on the original document present at the reading position and a second reflection angle of light reflected to the light receiving unit from the original document present at the reading position, when the original document at the reading position is interposed between the background member and the light source, and (iii) the first difference is smaller than the second difference; and a foreign substance detecting section that detects, when the original document is not present at the reading position, a foreign substance present at the reading position based on a result obtained by irradiating the background member with light having a light intensity lower than the intensity of the light for irradiation of the original document.