| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner that can optically scan a scanning target surface accurately at a high speed without causing an increase in size and cost.SOLUTION: At a timing at which light reflected on a rotary polygon mirror is directed to the center of a scanning area, all rays of light made incident on the rotary polygon mirror are reflected on one deflection reflection surface, and at a timing the light is directed to the ends of the scanning area, the rays of light made incident on the rotary polygon mirror are reflected on a plurality of deflection reflection surfaces including the one deflection reflection surface. Principal rays of a plurality of rays of light emitted from a light source are reflected on the rotary polygon mirror and intersect with each other when viewed from a direction parallel to a rotation axis of the rotary polygon mirror; when the distance between the intersecting position and reflection points on the rotary polygon mirror is d, the radius of an inscribed circle of the rotary polygon mirror is R, an angle formed by a direction orthogonal to both the main scanning direction and the rotation axis and an incident direction of light on the rotary polygon mirror is θ, and an inclination angle of the one deflection reflection surface is α, the relationship 0<d<Rcos(θ-α) is satisfied.SELECTED DRAWING: Figure 24 |
