Patent ID: 8693050

Claim:
A method for adaptive color control in a color adjustment system of a color marking device, the method comprising: receiving at least one target color value of a target color patch for a marking job on a color control system of a color marking device, said color control system controlling m actuators wherein individual actuator values can be represented by an input vector-u; receiving an initial sensitivity of a nominal actuator, said initial sensitivity having been determined by checking said actuator over a range said actuator is expected to vary to control color consistency of said target color value of said color control system; receiving at least one control parameter determined using said initial sensitivity, said control parameters being used to control color in said color marking device; and iteratively performing, during said marking job on said color control system, each of the following until adjustment to said actuators is within a given tolerance: measuring, using an image sensor, spectra for N reproduced color patches of said target color, where R j is the measured spectra of the j th color patch; determining a change in sensitivity of said measured spectra, said changing in sensitivity being used to update a spectral PCA-based model of said color control system, where: R=R 0j +Σ i=1 K j α i ψ ij +φ*( u )β where R is a predicted spectra, R 0j is a mean measured spectra, K j is a user-selected number of dominant basis vectors ψ ij , α i is a basis vector written as a function of said input vector u of individual actuator values, and φ*(u)β collectively comprises a learning algorithm where φ*(u) is a known matrix of functions of said input vector u, and β is a vector; updating said received control parameters based upon said updated spectral PCA-based model; and communicating said updated control parameters to said color control system, said color control system using said updated control parameters to adjust said actuators for adaptive color control.