Burn-in on CRT-based rear-projection televisions

I'm a huge fan of movies. I love all kinds of movies. I especially love movies when they're presented to me on a very large screen. Since I don't have enough money to constantly go out to the movie theater, I decided to go out and purchase a 52" Panasonic HDTV.
I was initially very happy with my new toy despite the fact that regular 4:3 television channels are stretched horizontally in order to fit the 16:9 screen (you can actually watch them in 4:3 mode, but you will burn black blocks on your $1700 television if you do that). I eventually got used to this stretching and now if I see a 4:3 program on a 4:3 TV, everyone looks too thin.

Now, as far as the HD piece is concerned...amazing. HD broadcasts are incredibly sharp and very high resolution. Unfortunately it took me battling with my cable company for six months before I could reliably receive HD channels. Go Comcast....good job.

Ok, so now for the burn-in betrayal. The user manual for the TV says not to play video games that contain static images on parts of the screen. Fine. I can understand this concept. Static images displayed for long periods of time will tend to burn-in on the screen, causing a ghost of that image to remain there for all eternity. This is a bad thing. What they fail to mention is that it takes *not a long time at all* for this burn-in to occur. It's a matter of a few hours. Also, it doesn't matter if you have the image displayed for a few minutes, then change the channel, then go back to the image, then change, etc...

It is a cumulative effect. It's like the screen is keeping track of how long it's *ever* displayed that image in that particular part of the screen and then after a certain length of time it says "HEY! This guy must really like this image to be here. Why don't I just put it here forever?"

So last year when the war with Iraq started, my brother glued his eyeballs to the Fox News Channel for several consecutive weeks, breaking to make runs to McDonald's and to get rid of waste (I assume). And since Fox News (like many other self-important purveyors of "news") is obsessed with flashy, glitzy on-screen graphics that make them appear official and important, they kept their slowly-spinning FOX NEWS logo down in the lower-left portion of the screen and the word LIVE in huge yellow letters up in the top-left. And apparently they didn't bother to run commercials for a few days. Anyway, I wasn't around much during that time and presumably the TV obediently displayed the Fox version of the war for a good while.

At some point after all this, I popped myself a bag of good old Orville and flopped onto the sofa to watch a re-run of the Sopranos when I noticed the images. I could see the words FOX NEWS and LIVE very clearly, especially when the sections of the screen in question displayed contiguous color. White seems to be the one that brings the little gems into sharp relief. So, for example, when I'm watching Six Feet Under (which uses fade-to-whites for scene transitions), they're just there glaring mockingly at me.

Almost a year later I can still see them, though I'm told that they eventually fade somewhat. I don't mean to say that this has ruined my television. Most times I don't even notice the images. I'm not sure if that's because I'm just used to it now or if they really are fading. But the bottom line is...be *very* careful when you buy one of these things. The picture is excellent, but somewhat vulnerable. The best idea is to do what I do now, have another TV that you use to watch these channels that insist on displaying logos, and just watch kick-ass movies on your big-screen.

Whether or not burn-in occurs depends upon the display technology used.

There are a total of five completely different technologies used today to create an image: Cathode-Ray Tube (CRT), Plasma, Liquid Crystal (LCD), Digital Light Processing (DLP), and Liquid Crystal on Silicon (LCoS). Only the first two are susceptible to burn-in, and Plasma is not a projection technology. Plasma and CRT, as they rely on the stimulation of phosphors, suffer from burn-in when an area of phosphors is held in the same state for too long.

The other four technologies are used in rear projection, and the two reflective technologies (DLP and LCoS) are immune from burn-in.

In other words, a CRT-based rear-projection display will suffer from burn-in, but a DLP- or LCoS-based rear-projection set will never suffer from burn-in of any kind. As mentioned, Plasma is also susceptible to burn-in.

LCD has a related burn-out problem, but it is not pattern-related. Since the light in an LCD projector passes through the LCD itself, the heat and light slowly destroy the crystals and polarizers. This results in a washed-out display.

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