Patent ID: 6198490
Filing Date: 2001-03-06
Classification: H04N

Abstract:
A printer comprising:a photoreceptor circulating along a path formed by a plurality of rollers;a plurality of optical scanning devices for emitting a scanning light toward the photoreceptor;a plurality of developing devices for supplying developing materials of different colors to the photoreceptor;a plurality of optical detectors for detecting part of the light emitted from the optical scanning devices;an engine controller for controlling a driving of the optical scanning devices, the developing devices, and the rollers using received light output from the optical detectors so that test patterns for each optical scanning device set to detect a color registration error between the optical scanning devices is formed on the photoreceptor;a pattern position detection means for detecting the positions of the test patterns formed from fixed positions through a developing process; anda color registration correction means for calculating a color registration error amount from the position information of the test patterns provided by the pattern position detection means, and calculating color registration correction data from the calculated error amount and outputting the calculated correction data to the engine controller,wherein the engine controller controls one selected developing device to develop electrostatic latent images formed on the photoreceptor in response to the test patterns by the optical scanning, devices with a single color developing material.