Optical element inspecting apparatus
US5847822A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 23, 1996 |
| Grant date | Dec 8, 1998 |
| Priority date | — |
| Expiry date | Aug 23, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/88
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical element inspecting apparatus for detecting an optical defect of an optical element to be inspected. The inspection apparatus includes a diffusion plate, a device for emitting light towards the diffusion plate such that a diffused light diffused by the diffusion plate is incident upon an optical system including at least the optical element, and a device for intercepting a part of the diffused light so that the part of the diffused light is not incident upon the optical system. The light intercepting device is positioned substantially in a plane perpendicular to an optical axis of the optical system, between the optical system and the diffusion plate, substantially at a focal point of the optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.