Patent ID: 8311428

Claim:
An image forming apparatus with a correction function for correcting density of an image, comprising: an image bearing member configured to convey the image in a first direction while bearing the image; and a controller configured to perform a bias correction and a γ correction for the density, wherein: the controller includes: a test patch generator configured to generate a test patch on the image bearing member, the test patch including a first test patch and a second test patch; a first density sensor configured to detect density of the first test patch to output a first detection signal corresponding to the density of the first test patch; a second density sensor configured to detect density of the second test patch to output a second detection signal corresponding to the density of the second test patch; a selector configured to compare the first detection signal with the second detection signal to select one of the first detection signal and the second detection signal as a bias-correction detection signal used for the bias correction while selecting another detection signal as a γ-correction detection signal used for the γ correction; and an adjuster configured to adjust the density by performing the bias correction based on the one detection signal and the γ correction based on the other detection signal, and the image bearing member bears the first and second test patches at positions separated in a second direction intersecting with the first direction.