Diffraction lens
US6429972B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 2000 |
| Grant date | Aug 6, 2002 |
| Priority date | — |
| Expiry date | Mar 1, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/4238
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A diffractive lens, comprises an optical axis; a lens surface having a peripheral portion, and a diffractive relief provided on the lens surface, wherein the diffractive relief is shaped in annular zones, and wherein following conditional formulas (1) and (2) are satisfied:hi−1≦h<hi  (1)x=f(h−hti)+S  (2)where i is a suffix showing an ordinal number of each of the diffractive annular zones obtained by counting each diffractive annular zone in such a manner that a diffractive annular zone including the optical axis is counted as a first diffractive annular zone and other diffractive annular zones are counted respectively in consecutive order from the optical axis toward the peripheral portion; h is a distance between a point and X axis in which, when the optical axis is deemed as X axis, the distance is from X axis to the point in a direction perpendicular to X axis; hi is a distance from X axis to a border between i-th diffractive annular zone and (i+1)-th diffractive annular zone which are counted from the optical axis in the above manner, provided that h0=0; f(h) is a function of h; hti is a constant in which at least one of hti is not zero; …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.