Torture Test: LCD vs. DLP

[Kevin P]

It looks like at least some LCD projectors have limited lifespans if heavily used, due to the heat breaking down the organics used in the LCD panels:

ExtremeTech torture tests LCD and DLP projectors




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[JonMarsh]

This is a bit like the accelerated life tests we run on semiconductors at Infineon for qualification, except that instead of being a 1,000 hour test, this is much longer.

DLP shouldn't have any degradation. I'm not too surprised that if you "bake" LCD panels this way that eventually they get a bit strange.

OTOH, let's correlate this to something resembling more "real world" usage at home. When I had my 400Q, or my Zenith FPTV's, the number of hours per week they were in use was probably under 10 hours. So, 1000 hours of use (with good cool down cycles between each use) would be 100 weeks, or about two years. For the LCD, time to replace the bulb. 10K hours of use would be 20 years. I think that's a pretty adequate lifetime.

I'm more interested to see if there are issues with the newer LCOS chips being developed, which reportedly have more stable and manufacturable structures; like the Sony SXRD.

With the performance it has, I can imagine being happy with that for 20 years, assuming I live that long! :LOL:

~Jon




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[George Bellefontaine]

Couldn't agree more, Jon.




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[Brandon B]

Boy, this topic is popping up everywhere. My response clipped from elsewhere.

About a 1/5 of the work I do is setting up PJ systems for our effects in our theme parks. We almost always use LCD or D-ILA in the rides as 3 chip DLP are (usually) too much $$$, and single chip DLP rainbow issues are a problem when viewed from a moving vehicle. Following is an excerpt from my post on this topic at AVS.

"... we have, in fact, seen just this kind of degradation.

We run our PJs 16 hours a day or so, 365 days a year. We do NOT see the degradation they are talking about in 3000 hours though.

Typically, it is well over a year when we start to see this, which translates to nearly double the amount of time they are saying. Our use does include one on-off cycle per day though.

We are actually gathering data on some of our systems to compare to this study some time this year. One of our people may present it at infocomm. "

In other words, we have experience with probably a couple of hundred projectors over the last ten years, in conditions ALMOST as abusive as theirs, and it appears their conclusions are a bit exaggerated. But NOT false. About what you'd expect when a reputable mfr with a vested interest sponsors a study.

Note: I own an LCD unit myself. At the price point I was at, no other technology had the brightness AND PQ I needed. I LIKE LCD projectors. DLP single chips annoy me.

The fact is, you are probably not going to see this kind of degradation in an HT unit in less than 5 years or more, unless you are running it 6 hours+ every day.

But with DLP, it will never happen.

BB

[Dean McManis]

Yeah, I agree that this is a biased test sanctioned by TI, who makes DLP chips.

DLP offers some distinct advantages like narrower pixels gap, better blacks and contrast for the most part, which I think far outweigh the rainbow problem (except for moving rides perhaps)

But LCD's reliability is very good, and most people will trade up their projector long before it breaks down or degrades.

I had a Sony LCD RPTV and put around 8000 hours (on the original bulb), and the picture quality was as good when I sold it as it was on the first day that I fired it up at home. 8)

-Dean.

[George Bellefontaine]

Even though I recently bought the NEC HT1000 dlp PJ, I still own and use a Sony VPL400 FP and after 4 plus years, still gives a great picture.




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