Boy, thiis article convinces me more than ever that those of us finding this study largely free of merit were right on:
From the article... "Five LCD projectors and two DLP projectors were tortured... Each projector was stressed continuously for thousands of hours.
Tortured and continuously stressed. Not the way any of us use our projectors.
In fact, Hall (op Epson) said that if this were a real problem, he would have seen lots of dealer and user complaints over the ten years that Epson has been selling LCD projectors.
From Epson, actual data. Not a bogus test enviroment.
The 24/7 testing environment was very harsh, and doesn't replicate how these projectors are used in most business settings today. During typical operation â€“ a few hours per day or per week -- many users might not experience noticeable problems for years. Of course, a larger study with multiple units emulating real-world "projector off" and "projector on" times could take multiple years to test, but only then could these results be projectable to most real world environments.
Fake conditions, irrelevant results. TI speculates on the causes of these "failures" in a slide included in the article. Many of us know from experience that without seeking to damage LCD panels in this matter, it is hard to do.
And I continue to insist that the cooling systems in these things are not designed to have the projectors protected against this kind of abuse. It continues to seem true to me that the crystal breakdown they were able to achieve would not occur in normal on/off use of the projectors. Or, if it would occur, it would take many thousands more hours of use.
whilst I don't disagree with Mark, the validity of torture tests is a moot point. TI are not alone in this kind of testing, most manufacturers use similar methods. If Ford slam the door on one of their cars 5,000,000 times and then it falls off are they going to worry, well not as much as if the brakes fail, but you can bet the designers will have a look at the failure report.
I did a research project on the effect of UV light on polymers and it is very destructive, more so than heat (IR) alone. Sunlight on curtains is a good example. One preventative measure is a reflective coating. So it is no surprise that transmission devices like LCD can be effected more than reflective DLP. NEC admitted as much in their use of UV filters. The higher the light intensity the more likely problems will occur. Cooling alone is not the answer here.
I would think their are enough Sanyp PLV-70 owners reading these threads to give some indication of real life problems if they occur.
BUT what I found the most worrying was that consumers only expect their PJ to last 3 years. Who are these people. If I was told that I would not be happy to spend $12k. The price of a car!
As TI and this article made clear, this has not been represented as a statistically significant sample. Having said that, I disagree with those that say the approach and results are invalid just because they compress a lifetime of use into a 10 month period. Accelerated life testing is commonly used and widely accepted. I have seen nothing here or in the other thread on the topic that described a real (as opposed to speculated) mechanism that would explain why running a display for 6000 hours straight is not the equivalent of running the display for 4 hours a day, for 1500 days.
If this test was run at "normal speed" it would have taken 5 years. Then some would be claiming the results are invalid because they were testing 5 year old technology.
While I also doubt just what if anything this limited test shows the process is a standard method of reliability testing for any competent hardware manufacturer. In over 20 years in the computer and IC business every single company has done this type of testing routinely, both on components and end hardware.
Remember that most projectors in both business conf. rooms and HT enthusiasts hands have very limited use. The potential problems that could occur at the 5 year horizon have no other way of being anticipated other than an accelerated life test.
If lack of dealer confirmation bothers you think of how often you have called a dealer or mfgr. tech support and been told " you're the first one to report this problem. "
Will the turkey be done in the oven. If you heat it in the oven many times with an eternally high temperture for a short time. What temperature does the meat thermometer get to measure in the center of what is cooking?
Compare this to turning on the oven and leave it there for half a year.
The test has validity but not the extent that a projector is dead when it is time for a lamp change. Real users have changed lamps and continued to use their projector.
Said it before. We install mostly LCD and DILA units in our theme park attractions (rainbows are easy to spot when you are movign past a projection in a vehicle of some sort) and we ahve, 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.
As other have pointed out, there is absolutely NOTHING unfair about testing projectors under continuous use, nor is is it much different than running a projector over the same period of time in small bursts. The issue has been reviewed in detail in these threads for those that wish to read them:
That does not mean that the study might not have been skewed in TI's favor. For instance, TI *might* have chosen LCD projectors for the study that they knew would be more prone to early degradation (due to poor cooling etc.).
p.s. The fact that ExtremeTech article commented on how "harsh" the testing environment was simply confirms that the author is "technically challenged".
Carl, you make some very good points. The fact is that in this case -- though -- TI's implication is that after 3,000 hours of use your LCD projector will be damaged irreparably. There just isn't real-world evidence to back up that claim vis a vis LCD projectors used in home theaters.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!