A high efficiency light valve projection system.
Abstract
A light valve (110,111,112) such as an active matrix LCD between crossed polarizers, utilizing, for instance individual transistors to control each "pixel area" of the LCD and storage elements to store video signal data for each pixel, with optically shielded "dead spaces" between pixels to eliminate electric field cross-talk and non-information-bearing light bleed-through, is illuminated with a bright independent light source (100,101,102) which creates a video image projected via specialized projection optics (140) onto an internal or external screen (150) without distortions, regardless of the angle of projection onto the screen. Use of heat sinks, IR reflective coatings, heat absorbing optics, optional fluid and a thermistor controlled pixel transistor bias voltage injection servo circuit stabilizes image performance maintaining accurate color and contrast levels as the LCD changes temperature. In one embodiment of the invention, use of a multi-color LCD with a stepped cavity, producing different thicknesses of LCD for the different wavelengths that pass through it, allows a linear correspondence between the wavelengths passing through the LCD to produce true black, high contrast and CRT-like color rendition. A dichroic mirror arrangement is used to overlap differently colored pixels in the projected image. Use of striped mirrors duplicate pixels, where necessary, eliminating spaces between pixels, creating a continuous image with no apparent stripes or dots. A special venetian-blind type of screen is also disclosed and methods for using the system to view three-dimensional video are also explained.

Term
Term ended
Projected expiry passed 22 March 2015, 11.5 years ago.
- Priority
- Filed
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- Projected expiry
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1 sheet
Sheet 1
Every citation, both ways
| Document | Relation | Office | Category | Cited during | Relevant claims |
|---|---|---|---|---|---|
| EP0271956A2 | Cites | European Patent Office (EPO) | XA | Search report | 1-4,8 |
| EP0307203A2 | Cites | European Patent Office (EPO) | A | Search report | 18 |
| GB1384567A | Cites | United Kingdom | A | Search report | 1,5,6 |
| DE3729512A1 | Cites | Germany | A | Search report | 26,43-46 |
| US4735495A | Cites | United States of America | A | Search report | 1 |
| US4765718A | Cites | United States of America | Y | Search report | 1-5 |
| US4826311A | Cites | United States of America | A | Search report | 18,20,22 |
| DE9210692U1 | Cites | Germany | YA | Search report | 1-5 |
| WO9215082A1 | Cites | World Intellectual Property Organization (WIPO) | XA | Search report | 33 |
| WO9416358A1 | Cites | World Intellectual Property Organization (WIPO) | PA | Search report | 26,43-46 |
55 members in 23 offices
Priority claims3
| Document | Office | Kind | Date |
|---|---|---|---|
| 223479 | United States of America | – | |
| 22347994 | United States of America | A | |
| US19940223479 | – | – | – |
Members55
| Document | Office | Kind | |
|---|---|---|---|
| WO8906417A1 | World Intellectual Property Organization (WIPO) | A1 | |
| IL88813D0 | Israel | D0 | |
| AU3059389A | Australia | A | |
| DK428389A | Denmark | A | |
| DK428389D0 | Denmark | D0 | |
| NO893473D0 | Norway | D0 | |
| CN1035904A | China | A | |
| NO893473L | Norway | L | |
| EP0346463A1 | European Patent Office (EPO) | A1 | |
| ES2011946A6 | Spain | A6 | |
| BR8807395A | Brazil | A | |
| KR900700992A | Republic of Korea | A | |
| NZ227529A | New Zealand | A | |
| DD283469A5 | German Democratic Republic (until 1990) | A5 | |
| US5012274A | United States of America | A | |
| AU616732B2 | Australia | B2 | |
| EP0346463A4 | European Patent Office (EPO) | A4 | |
| WO9215082A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU1428592A | Australia | A | |
| JPH04505811A | Japan | A | |
| EP0509630A2 | European Patent Office (EPO) | A2 | |
| PH27138A | Philippines | A | |
| CA1317044C | Canada | C | |
| MX168118B | Mexico | B | |
| KR930005372B1 | Republic of Korea | B1 | |
| DK76593D0 | Denmark | D0 | |
| EP0509630A3 | European Patent Office (EPO) | A3 | |
| AR243715A1 | Argentina | A1 | |
| MY103957A | Malaysia | A | |
| US5300942A | United States of America | A | |
| BR9205678A | Brazil | A | |
| IL88813A | Israel | A | |
| JPH0772443A | Japan | A | |
| AU663080B2 | Australia | B2 | |
| CA2146060A1 | Canada | A1 | |
| EP0676902A2 | European Patent Office (EPO) | A2 | |
| KR950034021A | Republic of Korea | A | |
| TW269010B | Taiwan Province of China | B | |
| CN1117633A | China | A | |
| EP0676902A3This record | European Patent Office (EPO) | A3 | |
| CN1032036C | China | C | |
| US5602679A | United States of America | A | |
| JP2589834B2 | Japan | B2 | |
| MX9501639A | Mexico | A | |
| RU2113066C1 | Russian Federation | C1 | |
| EP0346463B1 | European Patent Office (EPO) | B1 | |
| AT172044T | Austria | T | |
| ATE172044T1 | Austria | T1 | |
| DE3856255D1 | Germany | D1 | |
| US5900982A | United States of America | A | |
| DE3856255T2 | Germany | T2 | |
| US6392689B1 | United States of America | B1 | |
| US2003076423A1 | United States of America | A1 | |
| US7688347B2 | United States of America | B2 | |
| US2011019112A1 | United States of America | A1 |
8 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Application deemed to be withdrawnWithdrawn18D | 18D | |
| Information on the status of an ep patent application or granted ep patentGrantedSTAA | STAA | |
| First examination report despatched17Q | 17Q | |
| Request for examination filed17P | 17P | |
| Designated contracting statesAK | AK | |
| Search report despatchedPUAL | PUAL | |
| Designated contracting statesAK | AK | |
| Public reference made under article 153(3) epc to a published international application that has entered the european phasePUAI | PUAI |
Numbers
- Publication
- 0676902
- Publication, DOCDB
- 0676902
- Publication, EPODOC
- EP0676902
- Application
- 95104187
- Application, DOCDB
- 95104187
- Application, EPODOC
- EP19950104187
Titles6
- German
- Ein hocheffizientes Lichtmodulator-Projektionssystem.
- English
- A high efficiency light valve projection system.
- French
- Un système de projection à valve optique à haut rendement.
- German
- Ein hocheffizientes Lichtmodulator-Projektionssystem
- English
- A high efficiency light valve projection system
- French
- Un système de projection à valve optique à haut rendement
Classification
- CPC, 11
- H04N9/3152
- H04N13/189
- H04N13/194
- H04N13/239
- H04N13/261
- H04N13/286
- H04N13/305
- H04N13/31
- H04N13/324
- H04N13/337
- H04N13/363
- IPC, 3
- H04N9 31
- H04N13 00
- H04N17 00
Designated states17
- Contracting states, 17
- Austria
- Belgium
- Switzerland
- Germany
- Denmark
- Spain
- France
- United Kingdom
- Greece
- Ireland
- Italy
- Liechtenstein
- Luxembourg
- Monaco
- Netherlands (Kingdom of the)
- Portugal
- Sweden