Patent ID: 9188923
Filing Date: 2015-11-17
Classification: G03G

Abstract:
1. An image forming apparatus, comprising: a photo conductor drum; a development roller configured to adhere toner to an electrostatic latent image on the photo conductor drum in order to develop a toner image; and a pattern image generating unit configured to develop two pattern images that are two sets of plural test patches for calibration on the photo conductor drum; wherein each one of the pattern images includes the test patches corresponding to densities in gradation; the pattern image generating unit is further configured to set an interval between a top of the first pattern image and a top of the second pattern image so that a remainder for the interval divided by a density fluctuation pitch is larger than a length of the test patch; and the density fluctuation pitch is the product of a periphery length of the development roller and a ratio between a rotating speed of the development roller and a rotating speed of the photo conductor drum; wherein the pattern image generating unit is further configured to set the interval so that the remainder is substantially 50 percent of the density fluctuation pitch.