Abstract: A method is disclosed for calibrating a grey level recording printhead having a plurality of recording elements. The method comprises measuring a parameter of each recording element, the parameter relating to a recording characteristic of the element, in response to measuring the parameter, defining a set of cells of clock periods having time boundaries to determine a set of K quantized clock periods; defining a subset of one or plural contiguous grey values within a set of J grey values recordable by the printhead for recalculation of a subset k of quantized clock periods wherein the number k of quantized clock periods is less than the number K, and recalculating at least some time period boundaries and clock periods for the grey levels j without changing the K total number of K clock periods.

Abstract: A non-impact printer apparatus includes a printhead having a plurality of recording elements. The printhead further includes a non-volatile memory that stores prebinned data representing recording characteristics relative to the recording elements. The prebinned data includes (a) data associating respective recording elements with respective bins; and (b) data relative to a characteristic of each bin. A controller means is located off of the printhead for generating tables for correcting for non-uniformity of the recording elements. The controller uses the prebinned data for generating the tables.

Abstract: A method and apparatus for calibrating a gray level recording printhead having a plurality of light-emitting recording elements is described. In the calibrating method a light intensity of each recording element is measured. The light intensities measured are quantized into M first cells. For each cell an exposure time t (i, j) is determined wherein i is a number representing number of cells and varies from i=1, . . . M and j is a number greater than one representing a number of gray levels. The set of exposure times {t (i, j)} is sorted to remove duplicate times and define a subset of exposure times {t (k)}. A non-uniformity constant value u is associated with each exposure time t (k). Boundaries for plural second cells are defined wherein exposure times, t (k), within a cell are spaced within substantially about the value u from a time b (n) that is calculated from a cell boundary and also falls within the boundaries of each cell.