Polarization converting element group for projection apparatus and projection apparatus
US9122068B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 12, 2012 |
| Grant date | Sep 1, 2015 |
| Priority date | — |
| Expiry date | Jul 6, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3164
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A polarization converting element group for a projection apparatus is disclosed. The polarization converting element group includes a polarization beam splitter and a half wave plate. The polarization beam splitter splits a light beam into a first polarized light beam with a first polarization direction and a second polarized light beam with a second polarization direction. The half wave plate is placed next to the polarization beam splitter and reciprocally moves between the first and second position. At different time points, the half wave plate changes the polarization direction of the first light beam or the second light beam passing therethrough. With this arrangement, the light beam that exits the polarization converting element group will either be a uniform first polarized light with a first polarization direction or a uniform second polarized light with a second polarization direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.