Patent ID: 8351081

Claim:
A method for calibration of a marking device's output color as measured on a printed solid area patch, the method comprising: for each of a desired color separation in an n-separation marking device having at least one actuator per color separation which regulates an amount of colorant deposited on a substrate at the solid area level, said actuator having been set to a nominal operating point: selecting a target color parameter vector T at the solid area level comprising a point in color parameter space; printing a solid area patch of said target color on a substrate using said marking device and measuring said printed patch to obtain a nominal measured color parameter vector N; repeating for at least one iteration: setting said actuator to a new operating point; and printing said solid area patch using said marking device and measuring said patch to obtain a measured color parameter vector associated with said new operating point; determining a functional relationship between a predicted printed color parameter vector P and a corresponding actuator level using at least two of said measured color parameter vectors, said function relationship comprising a gradient {right arrow over (G)} defined as a function of high and low actuator operation points x H and x L , respectively, and color parameter vectors H and L, measured at said high and low actuator operating points x H and x L , respectively; using said gradient and said target color parameter vector T to determine a final actuator operating point for said marking device, said final operating point comprising an offset x from said nominal operating point, said offset defining a relationship between said gradient, said target color parameter vector T, and a point C between said color parameter vector L and H which minimizes a distance between said predicted printed color parameter vector and said target color parameter vector; and setting said actuator to said final actuator operating point.