Using Time-Sequential Sampling to Stabilize the Color and Tone Reproduction Functions of a Xerographic Printing Process
IEEE Transactions on Control Systems Technology
Tone and color reproduction functions (TRC and CRC) characterize how a printer maps a desired tone or color into the actual printed output. Ideally, the TRC/CRC should be identity maps to achieve tone and color consistency. The main contribution of this paper is in enabling the stabilization of potentially infinite dimensional TRC/CRC with limited sensing capabilities. This problem is challenging because: 1) only a small number of tone / color test patches for sensing can be printed and
... printed and measured at a time; 2) only a small number of actuators are available for control. To address the first problem, time-sequential sampling is proposed to enable the time varying TRC or CRC to be reconstructed based on small number of samples. A periodic Kalman filtering approach is employed for the reconstruction. Two classic time-sequential sampling sequences are compared based on their spectral aliasing properties. The second issue is addressed by a curve-fitting TRC stabilization controller based on Linear Quadratic (LQ) control with integral dynamics. It specifies particular tones or color to be precisely controlled, while allowing other tones or colors to be close to the desired value. Simulations and experiments show that the proposed TRC/CRC stabilization system is effective for practical implementation.