Questions about projectors - Engineer project

Hi!

I and five other engineer students at Aarhus University, Denmark, are currently doing som research on noise made by projectors. The goal is to reduce or potentially eliminate the noise.

We have some questions, and we would appreciate if you took the time to answer these.


1. Which type of projector technology is the most popular right now? (LCD, DLP, CRT, LED etc.)

2. Will we see any new tehcnologies soon? If so, which?

3. Is noise level an important factor for you, when purchasing a projector?

4. Would you be willing to pay 2-300 USD extra for a projector with a significantly lower noise level?

5. Is it only the light bulp that gets heated, and therefore needs cooling, or are other components in the projector in need of cooling?

6. How hot can the bulb get before it breaks down? And at which temperature is the bulb kept to secure it from breaking?

If you can't answer all the questions, just answer the ones you can.


If you know of any other forums where people would be able to answer the questions, or if you have a lot of knowledge about this yourself, please let us know.

Thanks!

Re: Questions about projectors - Engineer project

1. Right now, for front projection (you didn't specify,) LCD and DLP are the most popular (by sales.) Presently, LED-based projection uses an LED light engine (lamp) to drive a DLP imaging engine.

2. Future technologies right now on the horizon seem to be various interference engines (Silicon Light, among others, I believe) and laser-based imaging systems, which I believe are holographic/interference type engines.

3. I would imagine that noise-levels for home projectors are mostly under control - most of the <2000 ANSI lumen projectors are generally quiet enough for the home market.

4. In the North American projector market, I'd imagine that you'd need something VERY different to accept a $200-$300 price boost other than noise level. The small market is rather competitive at the moment.

5. The light bulb is one of the most obvious things in need of cooling, however it isn't the only thing. LCD panels, either transmissive or reflective (LCoS) need to be kept cool. DLP chips need to be kept cool. Some projectors do massive amounts of signal processing and need to keep the process-engines cool. And in projectors with variations of arc-lamps, the ballast/power supply needs to be kept reasonably cool. Reflectors and integrators need to be kept reasonably cool in larger projectors. (IMAX projectors dump massive amounts of water through their reflectors.)

6. This depends a great deal upon the light-engine technology. And lamp manufacturers should be able to help out a great deal on this. And the size of the lamp, the wattage of the lamp, and the technology of the lamp will all affect the acceptable skin temperature. In addition, the lamp skin needs to be kept even; if one side is significantly cooler than the other, then it's going to be a problem.

As an extension of #6, also look to the lamp materials. If the envelope of the arc-tube is fused quartz, then you should be able to find the melting point of the quartz fairly easily. Add into the fact that many small mercury-type arc-lamps pressurize to 10+ atmospheres of internal pressure while operating. Xenon arc-lamps may go much higher.

I know Panasonic's large-venue projectors (>6000 lumen 3-chip DLP) often have active noise suppression systems - active phase cancellation microphone and speaker systems in the air-paths and things like that.

Leo

Re: Questions about projectors - Engineer project

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