Patent ID: 9442406
Filing Date: 2016-09-13
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: a transfer member, onto which images of reference colors and images of a plurality of other colors are transferred while the transfer member is being rotated, the reference colors including yellow, magenta, cyan, and black, and the other colors being different from the reference colors; a plurality of first transfer units that each transfer the image of a corresponding one of the reference colors; a plurality of second transfer units that are disposed upstream of the first transfer units in a rotational direction of the transfer member and that each transfer onto the transfer member the image of a corresponding one of the plurality of other colors; a determination unit that determines differences in lightness between a first reference color and each of the other colors, respectively, the first reference color being the reference color of the first transfer unit which is disposed most upstream in the rotational direction among the plurality of first transfer units, wherein the lightness of each color is obtained by measuring a single-color image patch formed on the sheet member; and a warning member that issues a warning based on the differences in lightness determined by the determination unit.