Patent ID: 9576229
Date: 2017-02-21
CPC Classifications: G01N,G03G,G06K

Claim:
1. An image forming apparatus comprising: an image carrier; a forming unit configured to form a detection image made of a developing material on the image carrier; an irradiation unit configured to irradiate the image carrier having the formed detection image with light; a light-receiving unit configured to receive reflected light of the light irradiated by the irradiation unit and output a detection signal corresponding to a light-receiving amount of the reflected light including a specular-reflected light component; and a detection unit configured to detect a first value of the detection signal corresponding to a first position of one of the detection image on the image carrier and a surface of the image carrier with the detection image formed thereon, a second value of the detection signal corresponding to a second position on a downstream side with respect to the first position in a moving direction of the detection image, and a third value of the detection signal corresponding to a third position on an upstream side with respect to the first position in the moving direction of the detection image during a time when the detection image formed on the image carrier passes through an irradiation region of the irradiation unit, and to detect one of position information and density information of the detection image based on a difference between the first value and an average value of the second value and the third value.