Patent ID: 7667867

Claim:
A printing apparatus comprising: an exposing head comprising a plurality of light emitting elements arranged in a primary scanning direction whose luminance are separately controllable, said exposing head and a photosensitive material being movable relative to each other in a secondary scanning direction perpendicular to said primary scanning direction, said light emitting elements being controllable, during the relative movement of said exposing head and said photosensitive material, based on set exposure data to generate a test chart; a scanner for scanning said test chart to acquire scanning data; and a correction data generating means for setting correction data regarding the luminance of said light emitting elements based on said scanning data; wherein said scanner has a resolution capable of acquiring density of a plurality of areas formed by dividing, in the primary scanning direction, each of pixel lines on said test chart corresponding to the respective light emitting elements; wherein said correction data generating means performs: a pixel identifying process for identifying said pixel lines corresponding to said light emitting elements from said scanning data; a density data acquiring process for acquiring density data of a plurality of areas adjacent a middle position in the primary scanning direction of each of the pixel lines, among the plurality of areas arranged in the primary scanning direction for each of the pixel lines identified in said pixel identifying process; and a correction data generating process for generating said correction data based on the density data acquired in said density data acquiring process.