Patent ID: 8649095

Claim:
A diffraction grating lens comprising: a lens body; and a diffraction grating provided on a surface of the lens body, the diffraction grating including a plurality of annular zones having slopes inclined along a width direction and a plurality of step surfaces respectively located between the plurality of annular zones, wherein at least one of the plurality of annular zones extends from a first one of the step surfaces to a second one of the step surfaces and is light-transmissive across an entire area thereof along a width direction, and in the at least one annular zone from the first one of the step surfaces to the second one of the step surfaces, a light transmittance near at least one of two ends along the width direction is smaller than a light transmittance near a central portion along the width direction; and in the at least one annular zone, a surface roughness of the slope near at least one of the two ends along the width direction is greater than a surface roughness of the slope near the central portion along the width direction of the annular zone.