Patent ID: 8736904

Claim:
An image forming system, comprising: a plurality of image forming apparatus for forming an image on a sheet of paper, each of the plurality of image forming apparatus having a storage section and being connected with each other in a paper conveying direction; a color sensor for performing colorimetry on a density correcting chart formed on the sheet of paper by one of the plurality of image forming apparatus to output a voltage value as a colorimetry result; a taking-in section for taking in a density value as a colorimetry result of colorimetry performed by an external colorimeter on the density correcting chart; a plurality of paper feed trays; a density conversion data registering section for obtaining density conversion data composed of a combination of the voltage value and the density value based on the respective colorimetry results of the color sensor and the taking-in section, and storing the density conversion data into the storage section included in the image forming apparatus which forms the density correcting chart to be used for the colorimetry; a paper setting section for storing a tray paper profile representing set information of paper which is set in each of the paper feed trays, or a paper profile representing set information of each of the paper to be used in the image forming system, into a paper setting storage section, the tray paper profile or the paper profile being correlated with at least one piece of the density conversion data obtained by the density conversion data registering section; and a correction controlling section for making the plurality of image forming apparatus produce a density conversion table or a density conversion function for converting, at the respective plurality of image forming apparatus, the voltage value into the density value based on the density conversion data stored in the storage section included in the plurality of image forming apparatus, respectively, and making the plurality of image forming apparatus perform printer γ (gamma) correction based on the density conversion table or the density conversion function produced by using the density conversion data correlated with the paper profile of the paper to be used for the image formation or the tray paper profile of the paper feed tray loaded with the paper, the paper profile and the tray paper profile being stored in the paper setting storage section, at a time of the image formation.