Patent ID: 6628317
Filing Date: 2003-09-30
Classification: B41J,G02B

Abstract:
An optical printer comprising:a spatial light modulator having an array of micromirrors arranged in a row or in a matrix, said micromirrors being able to tilt each individually; a driving device for driving each of said micromirrors to tilt either to an effective reflecting position or to an ineffective reflecting position in accordance with image data; a light source section illuminating said micromirrors; an image projecting optical system for projecting printing light beams from those ones of said micromirrors which are in said effective reflecting position, as an optical image of a predetermined size onto a photosensitive material; a paper advancing device for advancing said photosensitive material intermittently by a length corresponding to the size of said optical image; a detection device for detecting fluctuations in advanced length of said photosensitive material by said paper advancing device; and a correction device having a piezoelectric element, wherein the correction device is configured to accumulate said fluctuations so as to determine an accumulated fluctuation value, and wherein the correction device is configured to correct a projecting position of said optical image on said photosensitive material by tilting said micromirrors by means of applying a voltage to said piezoelectric element in accordance with said accumulated fluctuation value.