Environmental and operational color calibration, with integrated ink limiting, in incremental printing

Abstract

At least one environmental condition that affects color of a printed image is automatically sensed, just before printing. That information is then used to modify printer operation, to compensate specifically for effects of the condition on color. This is preferably accomplished using a transfer function calculated just before printing. Also preferably taken into account is a principal color-calibration profile, not prepared just before printing but rather substantially constant. If a replaceable colorant-placing module is in use—selected from many such modules—and the particular module has a characteristic property (such as drop weight or age of an inkjet pen) which affects the color of printed images, then preferably information about that property of the particular module is also automatically used to modify printer operation, to compensate for effects of the distinctive property on color. Interactive effects of environmental conditions and module characteristics are preferably also accounted for. If the printing medium in use has a sensitivity to excessive colorant deposition of colorant, at least one environmental condition that affects that sensitivity of the medium to excessive deposition is also automatically sensed, just before printing; and this information is then automatically used to modify printer operation, to limit the amount of colorant deposited. Instructions for automatic operation are placed in a nonvolatile device at the time of manufacture. Sensitivity data are empirically assembled from test patterns and used, preferably in algebraically signed form in regression calculations, to find coefficients for use in polynomials used to calculate the transfer functions.