Patent ID: 8411342

Claim:
A light scanning unit, comprising: a source configured to generate light; a deflector configured to deflect the light generated by the source; and an optical imaging system configured to form the light deflected by the deflector into an image on a photosensitive medium, the optical imaging system including a first optical imaging lens and a second optical imaging lens, the first optical imaging lens and the second optical imaging lens collectively configured to have the functionality of an f-theta lens, wherein the optical imaging system is configured such that a first ratio of an f-theta scanning coefficient of the optical imaging system to a main scanning focal distance of the optical imaging system is higher than about 0.81 and lower than about 0.88, and a second ratio of the main scanning focal distance of the optical imaging system to a main scanning focal distance of the first optical imaging lens is higher than about 0.6 and lower than about 0.91.