Patent ID: 6034806
Filing Date: 2000-03-07
Classification: G02B

Abstract:
A light beam scanning optical apparatus comprising:a light source having at least three light emitting points;a converging lens for shaping light beam emitted from the light source, into at least one of generally parallel and convergent bundles of rays;a deflecting device for performing the deflection of and scanning with the light beams having outgone from the converging lens;a scanning surface which is to be illuminated by the light beams; andscanning optical elements for performing linear scanning on the scanning surface, with the light beams having outgone from the deflecting device;wherein scanning with light beams of which the number is n and which have been emitted from the light source is simultaneously performed at unequal intervals with respect to a direction of sub scanning on the scanning surface, and following relational expressions hold:h.sub.i mod n.noteq.0h.sub.i mod n.noteq.h.sub.j mod n(2.ltoreq.i.ltoreq.n, 2.ltoreq.j.ltoreq.n, i.noteq.j)wherein h.sub.k (2.ltoreq.k.ltoreq.n) is a position where kth light beam from a front extremity of an image is converged, which the position is measured with respect to the position where the first light beam from the front extremity of the image is converged on the scanning surface, and which position is expressed in units of an interval between scanning lines required by a given image density on the scanning surface, and wherein mod is an operator for finding remainder in the case that h.sub.i or h.sub.j is divided by n.