US Patent 7269369 Image forming apparatus with reduced paper consumption

In a color image forming apparatus, a user need not exchange a sensor, paper is prevented from being wastefully consumed, and image quality and color reproducibility can be improved. The color image forming apparatus includes a detecting unit which detects the density or chromaticity of a test image formed on a recording medium, and a correction unit which corrects the density or chromaticity of the image by using the detection result obtained by the detection unit. The detection units are arranged in the first direction perpendicular to the convey direction of the recording medium.