Printing apparatus with adjustable dot creation timings

Abstract

In a printer that creates dots with a plurality of color inks K, C, M, and Y in both a forward pass and a backward pass of main scan, a delay circuit is provided corresponding to each nozzle array, in order to change an ink ejection timing. The technique of the present invention prints seven test patterns, so as to specify dot creation timings with regard to the K ink in the backward pass, the C ink in both the forward pass and the backward pass, the M ink in both the forward pass and the backward pass, and the Y ink in both the forward pass and the backward pass relative to the dot creation timing with regard to the K ink in the forward pass set as a standard. The delay circuit delays an output timing of a driving waveform to a print head according to the specified dot creation timing. This arrangement effectively prevents a misalignment of dot recording positions with regard to all the color inks in both the forward pass and the backward pass of the main scan, thereby attaining high-quality printing. The delay circuit may be provided corresponding to each ink color or each nozzle group, for example, having a common nozzle driving mechanism, other than each nozzle array. The technique of the present invention is also applicable to adjust the dot creation timing with regard to each nozzle group in a printer that creates dots only in either the forward pass or the backward pass of the main scan.