Patent ID: 6233000
Filing Date: 2001-05-15
Classification: G06K,H04N

Abstract:
An image forming system which forms an electrostatic image on a photoconductive medium by scanning a laser beam across the photoconductive medium in order to create a multilevel image on a copy sheet from the electrostatic image through an electrophotographic process, comprising:an imaging data generator configured to generate a dot intensity data from each of a series of pixels contained in an input image, each pixel having bits indicative of an intensity of the pixel only, the imaging data generator including a plurality of discrimination patterns to detect the presence of one of a 1-pixel-thick vertical line and a multipixel-thick line edge in the input image; andan optical writing unit having a laser diode, configured to modulate at least one of an emission power and an emission time of the laser diode by using the dot intensity data output by the imaging data generator, and to determine the emission power of the laser beam per dot based on the dot intensity data, so that the laser diode emits the laser beam to the photoconductive medium in accordance with the modulation data, renders the 1-pixel-thick vertical line compatible in width with a 1-pixel-thick horizontal line, and renders the multi-pixel-thick line as a single multi-pixel-thick line without an intermediary channel of contrasting color,wherein corrected intensity values for the dot intensity data are predetermined in correspondence with the individual discrimination patterns, and when an intensity pattern related to a subject pixel and neighboring pixels thereof matches one of the discrimination patterns, the imaging data generator selects a corrected intensity value corresponding to the matched discrimination pattern as the dot intensity data, and when the intensity pattern does not match any of the discrimination patterns, the imaging data generator selects the intensity of the subject pixel as the dot intensity data.