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How to setup a ceiling mounted LCD projector
- Drill holes in ceiling, screw in projector bracket and mount projector, use long cables to plug projector into source material and power, grab some trunking pipe
- And here I thought LCD projector just a misnomer of video projector. 14:53, 20 July 2011 (UTC)
The LCD concept has 3 lcd panels for each color (Red, Green, Blue). Each LCD manage the image in it's own color. Since there is only one light source, it's decomposed via color filters, pass trough the 3 lcd and then recombined trough a prism to reform the image. Misaligned lcd's is easy and can be seen like an old tv set on the corners that colors had shift.
Proposed changes to History
A patent application was filed in Switzerland on Dec. 3, 1971 by Brown, Boveri & Cie with Alfred de Quervain and Peter Wild as inventors entitled Information-bearing Devices and Projection Display Systems therefor and published as US Patent 3,895,866 on July 22, 1975. The invention was based on an LCD cell in the transmissive mode, addressed as a passive, direct-driven matrix display, its intersections acting as individual light valves, mounted in a slide frame of a traditional slide projector. At the time it was not yet possible to implement such matrix arrays with sufficient resolution (number of pixels) to project images of typical complexity. Therefore, a combination of a static image with only a few variable elements implemented as an LCD matrix was proposed for particular applications. The US patent examiner did not mention any prior art related to Gene Dolgoff.
Such an LCD projection system was explained and shown in operation at the SID conference in San Francisco, CA by Peter J. Wild of Brown, Boveri & Cie AG in 1972 .
Passive (without TFT), matrix-addressed LCDs with sufficient resolution for displaying typical images are not possible using either DSM or TN LCDs (excluding e-beam-addressing). The invention of the super-twisted nematic (STN) LCD by a team at Brown, Boveri & Cie, Switzerland, in 1983 provided the long awaited breakthrough. More than 60 companies became licensees of the corresponding patents (US 4,634,229). This is why Dolgoff finally could realize his ideas in 1984.
A TI report on the evolution of projection technologies mentions the Sharp Corp. of Japan as first in launching a commercial LCD color projector in 1989.
I ask for comments before changing the article.
- P. J. Wild, J. Nehring: Turn-on Time Reduction and Contrast Enhancement in Matrix-addressed Liquid-crystal Light Valves, Appl. Phys. Lett., vol. 19, no. 9, pp. 335-336, Nov. 1971
- P.J. Wild, Matrix-addressed liquid crystal projection display, Digest of Technical Papers, International Symposium, Society for Information Display, June 1972, pp. 62-63
- J.A. van Raalte, Reflective liquid crystal television display, Proc. IEEE, Vol. 56, No. 12, pp. 2146-2149, 1968