Patent ID: 8559078

Claim:
An apparatus for measuring a color reproduction characteristic of an image forming apparatus, comprising: a colorimetric device for measuring color reproduction characteristics data, the colorimetric device generates a colorimetric chart including a patch column that is arranged in a sub-scanning direction representing a conveying direction in which the image forming apparatus conveys the colorimetric chart and that is used in detecting periodic color fluctuation attributed to the image forming apparatus, wherein the patch column includes patches that are arranged in different phases on the same patch column, wherein the image forming apparatus that includes a photosensitive drum, and wherein the patch column includes a plurality of patches of different colors, and the plurality of patches are either arranged: in a repeating fashion according to a non-integral cycle of a ratio Rt between a drum cycle of the photosensitive drum and the patch cycle of the plurality of patches of different colors or, when the ratio Rt is approximated to an integer equal to or smaller than five, arranged in a repeating fashion according to a cycle of the ratio Rt and in different phases.