Patent ID: 7692830

Claim:
A luminance nonuniformity adjustment method for calculating a luminance correction coefficient for each optical element determined through a test print using a light-sensitive material to eliminate luminance nonuniformities in said optical elements of a color laser print head, which controls a plurality of said optical elements in a linear array for each color of the three basic colors according to an exposure gradation value based on an image data to expose the light-sensitive material, the method comprising the steps of: calculating a provisional luminance correction coefficient by comparing a measured density value for a grayscale chart of areas having different density values and a predetermined target density value by a provisional luminance correction coefficient calculation unit of a luminance nonuniformity adjustment device; calculating an improper coloring degree, which is the degree of improper coloring that occurs when other colors are expressed when developing a specific color, from a measured density value corresponding to the grayscale chart and an unbalanced chart where the gray balance has been altered by an improper coloring degree calculation unit of said luminance nonuniformity adjustment device; correcting the provisional luminance correction coefficient using the calculated improper coloring degree to determined a final luminance correction coefficient by a luminance correction coefficient determination unit of said luminance nonuniformity adjustment device; and storing said final luminance correction coefficient in a correction table of said luminance nonuniformity adjustment device by said luminance correction coefficient determination unit of said luminance nonuniformity adjustment device.