Patent ID: 6791728
Filing Date: 2004-09-14
Classification: G02B

Abstract:
A scanning optical device comprising:a first optical system for guiding at least two light beams emitted from at least two light emitting points to deflection means; and a second optical system for imaging as light spots the at least two light beams deflected by the deflection means on a surface to be scanned, wherein the light beams incident to a deflection surface of the deflection means are set to light beams wider than the deflection surface in a main scanning direction and, in a main scanning section, when respective angles formed between the center axis of emitted distributions of the light beams from the at least two light emitting points and a corresponding optical axis of the first optical system are each given by &agr;i, two light beam angles in which a difference of the angles is maximum are given by &agr;1 and &agr;2, and a maximum difference formed between the angles of &agr;i is given by &agr;&egr;=|&agr;1âˆ’&agr;2|, respective total angular widths of radiation angles of the light beams from the at least two light emitting points within the main scanning section are given by &thgr;i, two light beam radiation angles in which a difference of the total angular widths is maximum are given by &thgr;1 and &thgr;2, and a difference of the beam radiation angles is given by &thgr;&egr;=|&thgr;1âˆ’&thgr;2|, 2&gE;|&agr;1âˆ’&agr;2|&gE;0 4&gE;|&agr;1+&agr;2|&gE;0, and 2&gE;&agr;&egr;/(1+&thgr;&egr;)&gE;0 are satisfied, where &thgr;i is a range up to 1/e2 of a peak of an intensity distribution of each of the light beams.