Process for correcting across-the-head nonuniformity in thermal printers.

摘要

The method of the present invention corrects the nonuniformity in the printing density between the printing elements (Hl . . . Hi) of a thermal print head (62) by first printing across a transparent receiver (64) with each element of the head activated with equal inputs (flat field). The print transmittance values are read from the transparent receiver (64) using, for example, a microdensitometer (88), and an adjustment factor ( DELTA Di, gamma ,N) for each heating element is computed and maintained in storage (90) to be combined with the number of heating pulses (Nij) assigned to each of the respective heating elements as they perform their normal printing function.