Printer and method of correcting color registration error thereof

Abstract

A color printer capable of detecting and correcting color registration error. The printer includes a photoreceptor belt circulating along a path formed by a plurality of rollers; a plurality of optical scanning devices for scanning light toward the photoreceptor belt; a plurality of developing devices for supplying developing materials of different colors to the photoreceptor belt; a plurality of detectors for detecting part of light emitted from the optical scanning devices; an engine controller for controlling the driving of the optical scanning devices, the developing devices, and the rollers, based on received light output from the optical detectors, so that test patterns for each optical scanning device set to detect the color registration error between the optical scanning devices can be formed on the photoreceptor belt; a pattern position detector for detecting the positions of the test patterns formed from fixed positions through a developing process; and a color registration correction calculator for calculating a color registration error amount from the position information of the test patterns provided by the pattern position detector, and calculating color registration correction data from the calculated error amount and outputting the calculated correction data to the engine controller. In color registration error correction using the printer, the positions of electrostatic latent images, corresponding to test patterns formed on a photoreceptor belt by optical scanning devices, are detected by developing the electrostatic latent images with a single color. Therefore, a structure for measuring error amounts from the test patterns is simple, and the accuracy of measurement can be improved.