Patent ID: 8240855

Claim:
A diffuser employed in a laser projection system for reducing speckle noise, the diffuser comprising a scattering pattern, wherein the scattering pattern comprises a plurality of scattering ribbons arranged in a direction of a first axis and extending in a direction parallel to a second axis, and each of the plurality of scattering ribbons comprises a second surface, wherein a height of the second surface with respect to a first surface defined by the first axis and the second axis varies based on a measuring point on the first axis, and the second surface satisfies the Equations ⅆ ⅆ x ⁢ h ⁡ ( x ) = - tan ⁡ ( β ⁡ ( x ) ) β ⁡ ( x ) = α ⁢ ⁢ x , where h(x) is a height of the second surface with respect to the first surface measured from a point x of the first axis if a point on the first surface corresponding to an apex of the second surface is an origin, β(x) is an angle between a line tangent to the second surface and the first axis, and α is a constant.