Patent ID: 7817176

Claim:
A device for optically scanning a target surface, comprising: a light source unit configured to emit a light beam; a light intensity detecting unit; a coupling unit configured to substantially collimate the emitted light beam; a beam limiting unit comprising a light shielding film or a light shielding material on a plate, and configured to limit an amount of the collimated light beam; a beam splitting unit configured to split the beam limited light beam and thereby to cause a first portion of the beam limited light beam to enter the light intensity detecting unit, wherein the light intensity detecting unit is configured to detect intensity of the first portion of the beam limited light beam; and a beam deflecting unit configured to deflect a second portion of the split light beam toward the target surface, wherein the beam limiting unit and the beam splitting unit are positioned between the coupling unit and the beam deflecting unit, the beam splitting unit is configured to split the light beam by diffraction, the beam limiting unit and the beam splitting unit are integrated on a substrate as a single unitary structure, and the beam limiting unit and the beam splitting unit are formed on the same surface of the substrate.