Patent ID: 7253937
Filing Date: 2007-08-07
Classification: G02B

Abstract:
1. A multi-beam optical scanning device, comprising: a plurality of light sources; a deflection unit configured to deflect a plurality of light beams from the light sources; a first optical system configured to guide the light beams from the light sources to the deflection unit; and a second optical system configured to guide the light beams deflected by the deflection unit to a scanning surface;, wherein the first optical system includes a first lens that couples the light beams from the light sources, and a second lens that guides the light beams from the first lens to the deflection unit, said second lens being an anamorphic element having power at least in a sub scanning direction, at least the second lens includes a diffracting surface having a power, and assuming a magnification in a main scanning direction of a whole optical system of the multi-beam optical scanning device is represented by βm assuming the power of the diffracting surface of the first lens in the main scanning direction is represented by P