Patent ID: 8556416
Filing Date: 2013-10-15
Classification: G02B,G02C

Abstract:
1. A diffractive multifocal lens, having an annular diffraction pattern for exhibiting a light diffraction effect, which is formed concentrically repeatedly on a surface of a lens, wherein a diffraction phase structure of the diffraction pattern has a structure expressed by the following formula: wherein each symbol is as follows: ξ indicates a position in a radial direction of the lens in one period of the diffraction pattern, having values from 0 to 1; w indicates a position where a form of the formula of φ(ξ) is changed; φ(ξ) indicates a value (radian) of a phase shift amount of light passing through the position of ξ from the phase of light passing through a reference plane; p p q indicates a parallel moving amount over the reference plane of the straight line φ(ξ) when satisfying w≦ξ<1−w.