Adjusting contrast in an optical system
US7061680B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 21, 2004 |
| Grant date | Jun 13, 2006 |
| Priority date | — |
| Expiry date | Jun 21, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/286
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An improved object projection system provides an observer with a surrounding background that has adjustable contrast levels relative to an object. A transmissive polarizer and a reflective polarizer change relative orientations. The change in orientation causes the level of light passing through the transmissive polarizer to change. In one system, the transmissive polarizer is placed in front of an object. A light source is placed in front of the object and behind the transmissive polarizer. A reflective polarizer is placed behind the object. The reflective polarizer provides the surrounding background for the object. A light source illuminates the object and the reflective polarizer. The object emits reflected light, which travels through the transmissive polarizer. Light from the reflective polarizer is transmitted to the transmissive polarizer. The level of light transmitted depends on the orientation of a transmissive axis of the transmissive polarizer to a reflective axis of the reflective polarizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.