Abstract: A color image printer includes a print engine (13) for effecting a laser scanning exposure and a test print managing section (51) for managing control for outputting a test print through the print engine for use in image quality adjustment. The test print (TP) includes a plurality of sets of horizontal stripe test patterns having a plurality of horizontal lines extending in the main scanning direction and a plurality of sets of vertical stripe test patterns having a plurality of vertical lines extending in the sub scanning direction. The horizontal stripe test patterns and the vertical stripe test patterns are arranged in alternation. And, the horizontal lines are formed with a gradation value set in advance for each horizontal stripe test pattern. The vertical lines are formed with a gradation value set in advance for each vertical stripe test pattern.

Abstract: A method of gradation correction for laser scanning exposure is effected, based on measured density values of a test print (TP) including a horizontal stripe test pattern comprised of a plurality of horizontal lines extending in the main scanning direction and a vertical stripe pattern comprised of a plurality of vertical lines extending in the sub scanning direction. The includes the steps of calculating, based on the measured density values, a rising correction amount for main scanning rising correction of adding a rising correction component to one dot after rising of a modulated laser in order to reduce density difference between the horizontal line and the vertical line and calculating, based on the measured density values, a falling correction amount for main scanning falling correction of adding a falling correction component to one dot after rising of the modulated laser in order to reduce the density difference between the horizontal line and the vertical line.

Abstract: A photo-printing system includes a laser exposure unit, a reference clock generation unit, an image input unit, and a controller. The image input unit receives first pixel data and second pixel data to be expressed after the first pixel in accordance with image data. In a first control, the first and second pixels are scanned for exposure in a laser emission region state wherein each of the scan-start timings of the first and second pixels are controlled in accordance with a reference clock. In a second control, the first pixel is scanned for exposure in a nonlinear light emission region state, and the second pixel having a density equal to or lower than a predetermined density is scanned for exposure in the laser emission region state, the scan-start timing of the second pixel is advanced with respect to the first control.

Abstract: A photo-printing system includes a laser exposure unit, a reference clock generation unit, an image input unit, and a controller. The image input unit receives first pixel data and second pixel data to be expressed after the first pixel in accordance with image data. In a first control, the first and second pixels are scanned for exposure in a laser emission region state wherein each of the scan-start timings of the first and second pixels are controlled in accordance with a reference clock. In a second control, the first pixel is scanned for exposure in a nonlinear light emission region state, and the second pixel having a density equal to or lower than a predetermined density is scanned for exposure in the laser emission region state, the scan-start timing of the second pixel is advanced with respect to the first control.