Projector Torture Test: LCD versus DLP

An anonymous reader writes "A ten month torture test of five LCD and two DLP projectors shows LCD images deteriorate during extended use." Not surprisingly, if you run an LCD projector for 4000 hours, it deteriorates... of course, if you're staring at a projecter 8 hours a day, for 500 straight days, maybe you should go outside ;)

Comments

Projector

[Anonymous Coward]

In other news...

most materials react in unplesant ways when exposed to 4000 hours of consistant bright light.

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From Ape to Man: Evolution

Here's a crazy idea...

[bluesoul88]

The LCD isn't deteriorating after 4000 hours, your eyes are.

Re:Here's a crazy idea...

[Mononoke]

Isn't the average lifespan for the bulbs in these projectors around 5000 hrs of use? Perhaps a weak bulb is incapable of providing a crisp image after that long.

Nope. Average lifespans are about 1500 hours. A weak lamp will only dims the image, it does not affect sharpness of the image.

Oh, and the LCD and DLP projectors both use the same type of lamps, with the same lifespans and problems.

Monitors?

[metalix]

Does this happen with LCD monitors as well?

Re:Monitors?

[apraetor]

The article mentions that TI believes the degradation is due to the intensity of the heat and light used in projectors. After all, a projector requires many many many times the candlepower of an LCD display's backlight. So I think we're safe :)

--matt

The real world

[b.foster]

of course, if you're staring at a projecter 8 hours a day, for 500 straight days, maybe you should go outside

This may come as somewhat of a surprise, but not everybody has a cushy job that lets them get away with working 5 hours a day.

Long life is often needed.

[sbaker]

> if you run an LCD projector for 4000 hours, it deteriorates... of course, if you're staring at a projecter 8 hours a day, for 500 straight days, maybe you should go outside ;)

But there are plenty of applications for these things where the display is permenantly turned on - think of a store display - or an airport information system - or high end adverts. In those cases, running 24 hours a day is very likely - and having the damned thing fail after a mere 166 days would suck badly!

It would have been nice to see the lifetime of large plasma panels in the survey too.

Re:Long life is often needed.

[cherry_eucalyptus]

Plasmas have actually come a long way since introduction and the lifespan is 25,000 to 50,000 (according to manufacturer studies) to the half-brightness point, which still isn't the end of the display's lifetime. Burn-in isn't really an issue if you take a reasonable amount of care with it (don't max out the contrast and if the station you're watching has bright static logos use the picture orbiter) and the off-axis viewing angle is 160 degrees. You still would not want to hit the screen though.

LCD is still better

[rufusdufus]

If I leave one image sitting on my LCD projector too long, yes, it will burn in a bit. But the burn in goes away after other images are shown. Typical desktop use gets no burn-in, while long bouts of Shadowbane will leave little yellow pock-marks when the fixed menus are. This goes away after browsing the web a while.

The problem with DLP projectors like the one my roomate bought is the "screendoor" effect that makes it look like you are viewing the image through a screendoor: little black boxes around every single pixel. This is an effect that is there from day-one and never goes away!

Will my LCD eventually get permanent burn-in? Perhaps. Still it's better than the screendoor.

Re:LCD is still better

[Daleks]

The problem with DLP projectors like the one my roomate bought is the "screendoor" effect that makes it look like you are viewing the image through a screendoor: little black boxes around every single pixel. This is an effect that is there from day-one and never goes away!

I think you're just looking at a DLP projector that has a very low resolution, or you're projecting it onto an area larger than it is designed for. We have one of these and it looks beautiful. No "screendoor" effect at all.

Re:LCD is still better

[Jeff DeMaagd]

Your impression is odd, I've never seen burn-in on any LCD type of display.

DLP usually has as good or better fill ratio than LCD, where the average DLP is about 85% fill ratio, LCD is typically around 60%. Go ask AVS Forum. If you see bigger "screen door" on a DLP, check to make sure that you are comparing the same resolution on the same projected area. When people complain about screen door, it is usually from the LCD crowd.

Now, DLPs do have a "rainbow" effect because all units below $10,000 new are single-chip and operate under the principle of flashing an entire screen full of one color before flashing the next screen full of the next color. In short, it is a very, very fast RGB strobe sequence that has no equivalent that I know of in any other display technology. DLPs also have some sort of flutter noise because the micromirrors flash on and off sequences to imitate brightnesses in between. But the thing is, not very many people really notice or complain about either problem.

Bulb costs?

[jeorgen]

Since the cost of light bulbs in projectors is really high, it would be interesting to know how many bulbs they burned through in the test for each projector.

Ink jet printers have very different running costs due to different costs for replacement ink cartridges. Does anyone know of a breakdown of running costs for different projectors or at least can share some experiences?

/jeorgen

Re:Bulb costs?

[NexusTw1n]

Bulbs last around 2000 hours. In a way they are similar to inkjet printers because they have a "REPLACE BULB" feature built in to the projector.

After 2000 hours your projector tells you to replace the bulb, you can still use it, but run the theoretical risk of damaging the projector when the bulb blows.

Bulbs in the UK cost £2-300 approx to replace, which is one years use at 8 hours a day 5 days a week.

So while they are a cool toy, you could buy 2 CRTs or one large LCD a year, or a wide screen TV every couple of years for the cost of one bulb.

Plasma screens are interesting, but in my experience you need graphics cards with plasma screen modes otherwise they are unviewable other than in 800x600 large icon and super large text mode.

Hmm this is actually very interesting

[tokaok]

I work as a projectionist at a theathre. we have 19 cinemas, lately we change all of our slides projector to lcd projectors(pre show adds).

we also have a DLP project or aswell.

the company, actually the whole industry would like to switch from film to digital projection to save cost.

Guess who is pretty much the only player in HIGH powere digital technology, you guessed it TI. TI makes the DLP projectors we all enjoyed watching StarWars/Disney animation on. Now you say that some project running for more than 5000 hrs is never going to happen at your housse, or maybe at your office but consider this.

our current project with bulbs, can go for about 8000-10,000 hours before the bulbs needs replacement. so we got through about 2/3 bulb a years per projector.

but only switch the bulb.

now the problem is that if after 8000 hours we have to switch more than just the bulb

(which is the case when a digital project goes bad if you ever owned one)

then this could really hurt TI in getting the theathres to switch over.

yep

[SHEENmaster]

and the "bright light" is really the paramedic's flashlight as he checks your ocular dilation.

Re:They didn't constantly watch the projectors

[ergo98]

Here's one. Hardly technical (the site is a high level type site) but very interesting.

Re:Huh...

[EdgeShadow]

8 hours a day for 500 days is about equal to 15 hours a day for 10 months (approximately 300 days).

More a stress-test than longevity-test

[Ra5pu7in]

According the to article, "TI and Munsell ran the projectors continuously 24/7, replacing bulbs as needed. Each projector was stressed continuously for thousands of hours."

There really wasn't much information provided on the methodology in this article. Did they leave just the one image or did it shift thru? Were any of the projectors shut off at any point (besides changing bulbs)? What were the conditions of the room/area in which the projectors were stored - ventilation, sunlight, etc.?

How many purchasers of projectors are going to use them non-stop? Just imagine such a stress-test of your Intel or AMD processor - 8000 straight hours of 100% CPU activity. I'm sure that could burn out a processor that would survive 8000 hours of activity without a hitch. The longevity of the LCD monitors may be much better than this implies -- which could be better tested under "normal" conditions.

My last thought is that I don't completely trust a "scientific" test done by a company to show the advantages of their own system.

Re:Extended use

[Anonymous Coward]

That is because the owners don't care for the projectors correctly. Also if pool hall allows people to smoke that is dramatically reduce the life of any projector.

I just happen to work on LCD and DLP.....

[Mark19960]

And, they are right.
The lamps degrade over time, as well as the panels.
I see so many projectors fail due to non-cleaning.
panel overheats are an issue... because no end user really owns a projector, they usually use one at work and none of these people bother to clean the units filter.
This just adds to the speed of the failure. most projectors I see have failures of the lamp and ballast units before the panels, probably because I get these downed projectors, find them filthy, clean and repair them before it kills the panels.
I have seen many, many kinds of projectors in both LCD and DLP, and the ones that seem to last longer are DLP units.
LCD units start biting the bullet after 3-4 years and usually after 2 years the image quality is starting to degrade.
My recommendation to anyone that has ant of these projectors is to clean them regularly, allow them to cool properly (another BIG problem) and, replace the lamp after the recommended usage.
some are 3,000 hours... some are 2,000...
If you do not replace the lamp after the usage limit, you risk an exploding lamp, damaged ballast, or main power supply. if its a DLP unit the color wheel can be shattered by an exploding lamp. I have had to replace quite a few of these because of this.
The projectors I find that fail the LEAST are made by Sharp and Toshiba. these are well made units that have lifespans of 10 years or more.
I see 10 year old sharps all the time. altho, the panels are about wasted.
Remember, keep the filters clean, allow the units to cool properly and change the lamps when recommended, and your unit should function for many years before needing service.

I hope that someone finds this infoarmation informative and useful.

many factors

[Lurking Grue]

I've been researching projectors since last fall, and am still on the fence regarding lcd vs. dlp. As a matter of fact, I've run across some cheap crt's as well. Not sure which way I'll go yet, but there are many factors to weigh in addition to what Texas Instruments has pointed out. (Not that their ownership of DLP patents could provide any agenda for publishing their report.) I don't purport to be an expert, or much more than moderately informed. But I have spent some time agonizing over the variety of projector technologies out there.

For some pretty honest feedback from projector owners and experts, check out avsforum. Check out comments from owners of dlp, crt, and lcd projectors. The folks in the forums are not afraid to either praise or pan a particular projector (or manufacturer or reseller), and they have been a great help to me in sorting out the various factors during my seemingly endless quest. (Actually, I'm just a bit too chicken to drop the $$$ right now.)

And there are quite a few factors worth noting. For instance, some people may be bothered by the "rainbow effect" that is generated by dlp projectors. Others may not be affected by that, but may be bothered by the "screendoor effect" of lcd projectors. Still others may be affected by the "pocketbook effect" of purchasing these things. I may well end up purchasing an LCD for around $2000, and then throwing it away after 4000 hours. (Which for me would be many years, since I watch less than 10hrs of TV per week.) Or I may spend around $4000 on a DLP and plan on keeping it a bit longer. In any case, I don't think I can make a bad choice since South Park will be kick-ass on 100" screen.

Something worth noting is that Sony does not produce any DLP projectors. They do produce CRTs and LCDs. While I'm not a huge fan of Sony, they do kinda have a decent reputation in the consumer electronics field. So to me, their presence in the LCD market lends a bit of credibility. (The HS-10 is getting killer reviews, and it's only around $2500.) Also worth mentioning is the fact that DLP projectors can suffer from image burn-in, while LCD projectors do not. It doesn't mean that LCD is better than DLP. But these are some of the differences worth knowing before dropping several thousand $$$ on a projector. Again, check out avsforum for lots of insight into the different technologies.

If you are interested in purchasing a projector, do your research. You'll probably find that there isn't any one "best technology" to go with.

Re:They didn't constantly watch the projectors

[Admiral Llama]

The short answer is that there's a small panel (DMD, digital mirrored device) with one tiny mirror per pixel (aka, over a million). Each mirror is individually motorized and flutters back and forth. One position reflects the light from the bulb down through the optics and to the screen. In the other position, it reflects the light into what's basically a light absorber.

Total light output is modlated by how much time the mirror is in the on position. The can each litterally flutter on and off over a thousand times a second. On dark areas of dark scenes you can see little scintelations of when individual mirrors flutter to the on position for a fraction of a second.

The fancier projetors have a light beam that's broken into red blue and green which then bounces off of three DMD panels before being recombined. The cheapie (less than $15K) ones have just one light beam that passes through a color wheel.

The color wheels typically have either RGB, RGBW (white), or RGBRGB. Better projectors have the RGBRGB wheels and spin at a higher rate. The result is that the projector winds up displaying a red image, a blue image and a green image in sequence. On fast moving items certain people (like me) are suscepible to seeing the different colors individually unless they spring for a higher speed color wheel, a triple DMD projector, or some other technology like LCD.

One last tidbit on the color wheel is that there is a new scroll color wheel coming out where at any given time there is a red, blue and green section being displayed over one third of the screen. They look like a pinwheel or one of those swirly lollypops. The trick to them is that the colors are actually dichoric mirrors so that only one given color light passes through while the other colors are then reflected back and hopefully recycled through one of the other two colors. It should more than total brighness while also lessening the effect of a slower speed colorwheel. Should be interresting.

unless..

[jkeegan]

> of course, if you're staring at a projecter 8 hours a day, for 500 straight days, maybe you should go outside ;)

Unless you're playing Halo on that projector, in case it's perfectly acceptable. :)

Re:I have seen this

[Admiral Llama]

Splotches are actually particles of dust blocking some light on one of the color panels. Take the projector far out of focus and the dust particle will come into perfect view. Just attack it with a can of compressed air. Also, really old projectors are going to look like hell if for no other reason that the new ones look really good.

Well, except for CRT projectors. Those things are still cherished even if the unit is 10 years old.

Ok, overclocking/cooling guys, do something useful

[Animats]

LCD displays deteoriate because the heat dissipated in the LCD elements fades the dyes in the liquid crystals. It's a cooling problem. So there's an opportunity for the overclocking/cooling crowd to do something useful here. Figure out how to cool down those things.

Big displays run continuously in control rooms and advertising applications. There's thus a market for long-life displays. Unlike home and conference room environments, silence isn't as critical. So aftermarket cooling solutions might actually sell.

Re:CRTs and radiation.

[Rolo Tomasi]

Only if it's a color CRT (which, even with modern designs, generates a non-trivial amount of soft X-rays due to the electrons slamming into the shadow-mask).

Fucking bullshit. Even if you watch TV (yes *gasp* in color) 12 hours every day, this amounts to a yearly dosage of about .5 uSv. Just for comparison, the average natural radition dosage (sun, cosmic radiation and incorporation of radionuclides) at sea level is about 2400 uSv/yr and travelling in an airplane for 50 hours a year would give you an additional dose of about 300 uSv.

Re:What is DLP?

[gilesjuk]

http://www.optomausa.com/DLP_demo/example_third_pa rty.htm

Basically a square of very tiny reflective mirrors with a spinning colour disc to colour the light they reflect.

DLP = Digital Light Processing.