Patent ID: 6922268

Claim:
A multi-beam scanning device, comprising: a first, a second and a third light emitting elements which emit a first, a second and a third light beams, respectively; a prism unit through which the first, second and third light beams respectively emitted by said first, said second and said third light emitting element pass; a deflector that deflects the first, the second and the third light beams emerged from said prism unit to scan in a main scanning direction; and an imaging optical system that converges the deflected first, second and third light beams to form beam spots on a surface to be scanned, wherein said prism unit includes a first prism into which the first beam enters, a second prism into which the second beam enters, and a third prism into which the third beam enters, said third prism being positioned between said first prism and said second prism, wherein said first prism being bonded to said third prism, and said second prism being bonded to said third prism, wherein a first reflective portion being formed on a surface on which said first prism and said third prism are bonded to each other, wherein a second reflective portion being formed on a surface on which said second prism and said third prism are bonded to each other, wherein said first reflective portion and said second reflective portion respectively reflect the first light beam and the second light beam emitted by said first and second light emitting elements toward said deflector, wherein said prism unit has a gap formed between said first reflective portion and second reflective portion, the third beam emitted by said third light emitting element passing through said gap.