Patent ID: 6977762

Claim:
An optical scanning device, comprising: a plurality of scanning optical systems configured to scan different scanning surfaces, each of the scanning optical systems comprising: a light source configured to emit a light flux; a deflector configured to scan the light flux emitted from the light source, wherein the deflector is commonly used in the plurality of scanning optical systems; a scanning lens configured to condense the scanned light flux to the scanning surface; an optical path inflection mirror configured to inflect the scanned light flux; and an imaging lens configured to lead the light flux emitted from the light source to the deflector, wherein the plurality of scanning optical systems are provided at both sides of the deflector with the deflector being therebetween such that one each of the scanning optical systems at both sides of the deflector comprise a set of the optical scanning system and respective light fluxes scanned by the deflector, the set of the optical scanning system being approximately parallel in a main scanning direction, and wherein an expression, | N−M|= 2 k +1 is satisfied when a number of optical path inflection mirrors provided in each of the set of scanning optical systems is respectively represented by “N” where N≧2, “M” where M≧1, and where “k” is an integer equal to zero or larger.