Patent ID: 9229349
Filing Date: 2016-01-05
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: a first image forming unit configured to form a first image using a toner of a first color; a second image forming unit configured to form a second image using a toner of a second color having lower reflectivity than that of the first color; an image carrier to which the first image and the second image are transferred; a controller configured to control said first image forming unit and said second image forming unit to form a first measurement image and a second measurement image on said image carrier, respectively, wherein the first measurement image including a first pattern formed by said first image forming unit and a second pattern formed by said second image forming unit, wherein the second pattern being superposed on the first pattern in the first measurement image, wherein the second measurement image including a third pattern formed by said first image forming unit and a fourth pattern formed by said second image forming unit, and wherein the fourth pattern being superposed on the third pattern in the second measurement image; an irradiation unit configured to irradiate the first measurement image and the second measurement image with light; a light-receiving unit configured to, in a case where said light-receiving unit received reflected light from the first measurement image, output a first signal corresponding to reflected light from the first measurement image, in a case where said light-receiving unit received reflected light from the second measurement image, output a second signal corresponding to the reflected light from the second measurement image, and, in a case where said light-receiving unit received reflected light from said image carrier, output a third signal corresponding to the reflected light from said image carrier; a setting unit configured to set a threshold value based on the second signal and the third signal output from said light-receiving unit; a determination unit configured to compare the first signal and the threshold value and determine information on a positional relationship between the first image and the second image based on a comparison result; and a correction unit configured correct for a color misregistration between the first image and the second image based on the information.