Patent ID: 9442447
Filing Date: 2016-09-13
CPC Classification: G03G

Claim Text:
1. An image forming apparatus comprising: image carriers; a charging unit that charges the image carriers; an exposing unit that forms latent images on the image carriers; a developing unit that develops the latent images formed on the image carriers with toners of different colors from each other; a first transfer unit that forms a color image by superimposing and transferring the latent images developed on the image carriers onto a second image carrier moving in transfer positions facing the image carriers; a second transfer unit that transfers the latent images transferred to and formed on the second image carrier onto a transfer material; a test pattern forming unit that forms test patterns on the image carriers to be transferred onto the second image carrier; a plurality of test pattern detection units that are capable of detecting test patterns transferred onto the second image carrier in a plurality of positions in a main-scanning direction; and a control unit that changes image forming conditions in response to detection results of the plurality of test pattern detection units, wherein the test pattern forming unit, based on a width in the main-scanning direction of at least one test pattern in a group of test patterns yet to be formed, switches between: wherein the test pattern forming unit does not form a respective test pattern from the group of test patterns yet to be formed when (a/2+c)≧b is satisfied, and forms the respective test pattern when (a/2+c)<b is satisfied, wherein