Projector with sealed light valve

1. A projector incorporating a prism and a light valve for modulating light that passes though said prism, the improvement comprising:

an air channel provided between an imaging surface of said light valve and said prism, wherein said light valve is mounted by a support mechanism and defining said air channel between the light valve and the prism, sides of the air channel being open for airflow to cool and minimize dust from the air channel settling on said light valve.

wherein the light valve sits flush with the inside surface of the air channel and said air channel is of uniform cross-sectional area and sufficient length relative to said imaging surface to provide at least partially laminar airflow between the prism and the imaging surface of the light valve.

2. A projector incorporating a prism and a light valve for modulating light that passes though said prism, the improvement comprising:

an air channel provided between an imaging surface of said light valve and said prism, wherein said light valve is mounted by a support mechanism and defining said air channel between the light valve and the prism, sides of the air channel being open for airflow to cool and minimize dust from the air channel settling on said light valve,

wherein said air channel is attached to said light valve by means of said support mechanism so as to permit convergence adjustment.

3. A projector incorporating a prism and a light valve for modulating light that passes though said prism, the improvement comprising:

an air channel provided between an imaging surface of said light valve and said prism, wherein said light valve is mounted by a support mechanism and defining said air channel between the light valve and the prism, sides of the air channel being open for airflow to cool and minimize dust from the air channel settling on said light valve; and

a gasket for sealing the air channel against the prism.

4. A projector incorporating a prism and a plurality of light valves for modulating light that passes though said prism, the improvement comprising:

air channels provided between an imaging surface of each said light valve and said prism, wherein said light valves are mounted by a support mechanism and defining said air channels between the light valves and the prism, sides of each of the air channels being open for airflow to cool and minimize dust from the air channel settling on respective ones of said light valves; and

a fan, a manifold connected to said fan, and a plurality of ducts connected between respective ports of said manifold and respective ones of said air channels for blowing air through said respective air channels to cool said light valves.

5. The projector according to claim 4 further comprising a filter adjacent the fan to reduce dust in said air channels.

6. The projector according to claim 4 further comprising a filter capped to at least one end of each of said air channels to prevent dust from re-entering said respective light valves when the fan is switched off.

7. The projector according to claim 4 further comprising means for increasing the speed of said fan to generate turbulent air flow in said air channels for purging dust that has settled on the light valves.

8. A projector incorporating a prism and a plurality of light valves for modulating light that passes though said prism, the improvement comprising:

air channels provided between an imaging surface of each said light valve and said prism, wherein said light valves are mounted by a support mechanism and defining said air channels between the light valves and the prism, sides of each of the air channels being open for airflow to cool and minimize dust from the air channel settling on respective ones of said light valves,

wherein said air channels are connected in series with a fan to form a closed loop air circulation system.

9. The projector in claim 8 further comprising a heat sink adjacent said fan for radiating heat collected by said air circulation system.

10. The projector of claim 9 further comprising an additional fan for cooling said heat sink.

11. The projector according to claim 9 wherein said heat sink is an air-to-air heat exchanger.

12. The projector according to claim 9 wherein said heat sink is an air-to-water heat exchanger.

13. The projector according to claim 8 further comprising means for increasing the speed of said fan to generate turbulent air flow in said air channels for purging dust that has settled on the light valves.

14. A projector incorporating a prism and a plurality of light valves for modulating light that passes though said prism, the improvement comprising:

air channels provided between an imaging surface of each said light valve and said prism, wherein said light valves are mounted by a support mechanism and defining said air channels between the light valves and the prism, sides of each of the air channels being open for airflow to cool and minimize dust from the air channel settling on respective ones of said light valves,

wherein said air channels are connected in series with an external pressurized source of clean gas air for purging said dust.