Projection display device
US6089718A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1998 |
| Grant date | Jul 18, 2000 |
| Priority date | — |
| Expiry date | Jul 15, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/3167
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
All light polarized in random directions is converted into s-polarized light and emitted by a polarizing conversion element 140. Linearly polarized light to be modulated is made incident on three liquid crystal light valves 250, 252, and 254, and p-polarized green light and s-polarized red and blue light are made incident on a cross-dichroic prism 260. Accordingly, for example, .lambda./2 phase plates 310 and 312 are respectively located in the optical paths before the first and third liquid crystal light valves 250 and 254. The .lambda./2 phase plates may be placed at various positions in the optical paths between dichroic mirrors 210 and 212 and the cross-dichroic prism 260.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.