Lens meter without relatively moving optical parts
US4130361A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 1977 |
| Grant date | Dec 19, 1978 |
| Priority date | — |
| Expiry date | Jun 6, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0228
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A lens meter for analyzing suspect lenses in terms of sphere, cylinder and axis by optical beam deflection and without relatively moving optical parts is disclosed. A light source emanating a substantially collimated beam of light from an entrant aperture into a retroreflecting mechanism includes two important properties. The first property is that an image of the entrant aperture is displayed from and reimaged across the optical axis of the retroreflector to a conjugate location at a real image exit aperture, this aperture being provided with a coincident optical stop. Secondly, in the absence of a test lens in the light path, light entrant to the retroreflector through the entrant aperture along a first path departs the real image of the exist aperture along a second path with a known angularity to the first path. Assuming that a suspect lens containing components of sphere and cylinder is interposed to the entrant and exit aperture, this angular deviation changes across the lens sampling entrant-exit aperture base leg. Specifically, the changed angular deviation is a function of sphere and cylinder present in the suspect lens. By algebraic summing of the resultant angular deviat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.