Patent ID: 9557562
Date: 2017-01-31
CPC Classifications: B41J,G02B,G03G

Claim:
1. A laser scanning unit comprising: a first light source, a second light source, a third light source, and a fourth light source; a deflector to deflect a first light beam, a second light beam, a third light beam, and a fourth light beam that are incident on the deflector from the first through fourth light sources at an angle with respect to a sub-scanning direction; at least one optical path changing member to change first through fourth optical paths of the first through fourth light beams that are reflected by the deflector; and a 1-1 f-θ lens, a 1-2 f-θ lens, a 1-3 f-θ lens, and a 1-4 f-θ lens to focus the first through fourth light beams, respectively, from the at least one optical path changing member onto corresponding scanning target surfaces, wherein each of the 1-1 f-θ lens, the 1-2 f-θ lens, the 1-3 f-θ lens, and the 1-4 f-θ lens is disposed such that each of the first through fourth light beams passes through a center of a corresponding one of the 1-1 through 1-4 f-θ lenses in a state of being offset in the same direction with respect to an optical axis of the corresponding one of the 1-1 through 1-4 f-θ lenses in the sub-scanning direction, and wherein the optical axis of each of the 1-1 f-θ lens, the 1-2 f-θ lens, the 1-3 f-θ lens, and the 1-4 f-θ lens is perpendicular to the sub-scanning direction.