Patent ID: 7133623

Claim:
An image forming device comprising: an image forming portion forming, based on data indicative of tones in a predetermined entire tone range, at least one measurement patch for density correction each having density, the at least one measurement patch including at least one specific-tone patch each corresponding to a specific tone; a first density-measurement unit measuring the density of the at least one measurement patch; a storage portion storing estimation data for estimating, based on the density of the at least one specific-tone patch, density of at least one other-tone patch having a tone different from the tone of the at least one measurement patch, wherein the at least one other-tone patch has a same color as the at least one measurement patch; and an estimating portion estimating the density of the at least one other-tone patch, based on both the estimation data and the density of the at least one specific-tone patch measured by the first density-measurement unit, wherein the estimating portion estimates the density of the at least one other-tone patch that is not formed.