6 Misconceptions of LCD TV

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LCD TV Misconceptions:

Six Common Myths About LCD Displays

The article I wrote about the most common misconceptions about plasma TVs has been so popular that I've decided to write a companion article, this one about LCD displays and the misconceptions floating around about them.

Misconception #1: Liquid crystal diode (LCD) displays actually contain liquid.

This is an understandable misinterpretation of the term "liquid" as it is being used here. In this case, the term refers to a peculiar quality of a certain type of crystal, not its physical appearance.

The twisted nematic (TN) liquid crystal is the most common type of liquid crystal being used in display applications today (e.g., LCD televisions, LCD monitors, and LCD projectors). It has a naturally twisted crystalline structure. A particular feature of this crystal is that it reacts to electric currents in predictable ways—i.e., by untwisting to varying degrees depending on the voltage of the current to which it is exposed. Hence the "liquid" part of the crystal's moniker: Rather than being an oxymoron (How can a solid also be a liquid?), the term refers to the relative pliability of the crystals themselves, which is to say, their twistability.

To learn more about how liquid crystals are utilized to display video and graphic signals, see my article, "How Do LCD Televisions Work?".

Misconception #2: LCD TV sets last forever.

They say nothing lasts forever—and neither do LCD televisions. The average lifespan of an LCD display is 60,000 hours. If watching TV was your full-time job, and you did it 24 hours a day, it would take you almost 7 years to wear out your LCD display. With more normal viewing habits of, say, 8 hours per day, you can extend the lifespan of your TV by a decade or more (to about 20 years)!

A more immediate concern is the actual lifespan of the light source in your LCD. This is perhaps THE critical component of your display unit. It is particularly important for maintaining a proper white balance on your TV. As these florescent bulbs age, colors can become unbalanced, which could result in too much red, for example, in your picture. So, it pays to buy name-brand displays. You will definitely pay more for better LCD display brands like Sharp, Toshiba, JVC, or Sony than you will for cheap Chinese or Korean variety knock-offs, but you'll get a backlighting bulb of higher quality and, in the end, a TV whose colors will stay truer longer.

NOTE: As far as I know, Sharp flat-panel LCD TVs are the only ones on the market whose backlights can be replaced by consumers themselves.

To learn more about the longevity of plasma displays and steps you can take to prolong the life of your television, see my article, How Long Do LCD TVs Last?

Misconception #3: LCD TVs suffer from burn-in.

Absolutely untrue. LCD monitors work by blocking light, so it is literally impossible for burn-in to occur on the screen. LCD TVs are sometimes referred to as "transmissive" displays, meaning that light isn't created by the liquid crystals themselves. Instead, a light source (bulb) behind the panel shines light through the display, which uses liquid crystals to manipulate the intensity of that light. When light is generated from a source external to the display screen itself, images cannot be permanently—or even temporarily—retained.

Misconception #4: You can't watch an LCD TV from the side.

This is a source of constant carping for LCD aficionados—limited viewing angles. It is sometimes the case that LCD displays have impaired side-viewing angles. Of course, most manufacturers will tell you just the opposite, that LCD TVs have viewing angles to rival comparably-sized plasma displays (i.e., 160° or more). But this is simply not the case. While it is sometimes possible to view LCD televisions 80° off axis, the picture you'll see will be degraded. In other words, there will be a noticeable decrease in color saturation, contrast, and brightness in the picture.

Quality really makes a difference in terms of viewing angle: If you buy an LCD display from one of the better manufacturers (e.g., Sharp or Sony), you should be able to sit about 70° off axis and still see a perfectly displayed imaged. Dot pitch is an important factor here. Higher dot pitches increase the viewing angles of LCD panels. Since dot pitch is measure in millimeters (mm), a good rule of thumb is this: Smaller dot pitches make for sharper images. You generally want a dot pitch of .28mm ("10,000 pixels/in2 of your display) or finer.

To get an idea of how various models stack up in terms of actual viewing angles (rather than stated viewing angles), see Robert Wiley's "5 LCD TV Shootout" article.

Misconception #5: LCDs are no good for watching action flicks.

Recent advances in LCD technology have markedly increased the response time of these displays, resulting in even smoother on-screen presentations. One way to think about response time is in terms of the amount of time it takes a pixel to "refresh" itself-i.e., to go from being active to being inactive, which is to say, ready to be re-activated). Response time is measured in milliseconds (ms), with the best LCD monitors now clocking in with response times under 20ms. Slower response times (>20ms) can cause the image on the panel to lag and appear jerky, an effect known as "streaking" or "trailing." Another phenomenon associated with slower response times is "ghosting." This occurs when the display is made to switch quickly from light to dark states (or vice-versa). In these instances, on-screen images may appear to stay on the screen belatedly.

The size and the quality of LCD panels determines how much or how little on-screen movement results in trailing effects. Better quality LCD displays have benefited much from improved response times. Still, no LCD display is entirely immune from trailing effects, though response times are expected to reach the under- 5ms mark soon.

Misconception #6: LCD TV is replacing plasma TV.

Some say that LCD is replacing plasma as the premier flat-panel display technology. Not so. While LCD may seem like the obvious technology for digital signage applications, given its relative durability and imperviousness to burn-in, LCD monitors have not exactly outpaced their plasma counterparts in the commercial arena. Nor has LCD technology beaten-out plasma as the best-selling home-theater appliances in America. In May 2004, plasma displays accounted for 47% of all 30" to 39" monitors sold in the U.S. The remaining 53% of the market share went to LCD TVs. LCD TVs certainly have the edge in the under-40" display category—then again, this is the market segment LCDs are supposed to dominate. When you look at the 40" to 49" screen-size market, the one where flat-panel display account for a full 43% of total sales, plasma technology reigns supreme, particularly in the very hot 40" to 42" segment.

A major reason for plasma's continued dominance in the over-30" display market is cost: 40" LCDs, for example, cost on average $1800 more than 42" plasmas. So, in the price-to-size comparison, plasma TVs continue to beat out LCD TVs hands down.

So, anyone who says that LCD technology has displaced plasma technology is sorely mistaken. While LCD displays have become increasingly visible in the fixed-pixel display market, plasma is still king in the over-40" display
category.




soruce:
lcdtv buying guide

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NeptunesFinest

I agree with everything except #3. It is rare, but sometimes LCD's do burn in. Trust me...I have seen it with my own eyes. I know there are plenty of people who will probably say that it wasnt burn in but it was. It was actually more permanant than on a plasma which you can usually fix pretty easily these days. If you dont believe me do a google search and read about it.

1080i Ownz

Do you have a DLP misconception list?

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sl7vk

Good post. Applicable to Plasma and LCD lovers.

Here is the Plasma version by the same author for anyone interested.


http://www.plasmatvbuyingguide.com/p...nceptions.html

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iserum

I disagree with #3 and #4.
I have seen LCD burn in at CC fniding nemo menu screen was completely burn in on Magnavox 26 inch LCD. I did ask the salesman specifically what it takes to burn in image on LCD he said aperantly we left it there for long period of time.
the 4th one is the viewing angle since i have both plasma and Flat pannel LCD being flat panel LCD very latest model from Toshiba, i can see the difference in viewing angle with washed out colors on LCD set. I have seen same thing on Sharp Aquos that i bought and returned for Panny plasma.

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S0LE_SURVIV0R

Panasonic claims to have good anti burn, pixel shift technology on plasma. Yes I heard of burn on LCD, meaning, if you make it a mission to give it screen burn. For the most part, you don't have to worry about screen burn on a LCD. People didn't worry about burn on old fashioned CRT tube sets, and CRT tube sets are more prone to burn than LCD. So unless you make it a mission for burn or leave something on pause for along LONG time, don't worry about burn.
The article quoted in a way contradicts itself. In one way it says that LCD's or nothing lasts forever, then it talks about the longevity of the light source. Yes, it's true, between 30-60 thousand hours the light will begin to give, but what electronic stores fail to tell you is that the back light on LCD FLATS can be replaced by a professional. Out of being curious I called Sony for a part replacement of the Sony XBR back light, they gave me a price of a few hundred. So yes, when you replace the back light after 20 years it should restore to set to out of the box conditions.
I have both a plasma & and LCD, I bought this plasma because I split my viewing between the two sets, and watch the plasma for about 2 and a half hours a day. At best that is about 1000 hours a year. So it will be 30 years, if I live that long, before the set reaches half life. But If I had to go with one, it would be the LCD, but a real good one.

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kittyman

im pretty sure what you experienced on these tvs was "burn in" in its most literal sense, rather something called "image transistence". Ive heard that white wash will get rid of "image transistence" in the same way that plasmas get rid of burn in.

RandyWalters

Sorry but i have to disagree with #4. I have a new HP LC2600N LCD temporarily set up directly next to my 42" Panny plasma while i fiddle with the settings to get the colors and brightness and contrast to mimick that of the plasma.

If i sit directly in front of the LCD TV it looks almost as good as the plasma next to it, but as soon as i move a few feet off to the side the picture on the LCD starts to wash out and the further off to the side i get the more the picture washes out. When i move to my couch my viewing angle is about 45 degrees and the LCD gets very washed out where the plasma remains the same. I don't see how the LCD manufacturers can claim they have wide viewing angles because i know what i'm seeing in my own living room. I see the same thing on my bedroom LCD TV - i have to turn it about 30 degrees and tilt it downward so it points to my pillows.

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Recherché

I agree with Randy Walters

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billinprinceto

The real misconception here is that a liquid crystal display is a diode display - which it is not.

LCD means Liquid Crystal Display.

Perhaps the confusion comes from LED which is a Light Emitting Diode, but is also a completely different animal.

Ntruder

I will personally never buy an LCD TV ever again. Of all the technologies I've owned, LCD was the only one that I actually returned to the store.

billinprinceto

Misconception #4 is given as:

And goes on to say: (arranged for clarity)

Seems the explaination of the "misconception" proves the "misconception" to, in fact, be correct.
Or . . . It is not a "misconception" that you can't watch LCDs from the side; it is a FACT that you can't watch LCDs from the side (without experiencing noticable degradation in picture quality).

Anyway, I just checked my LCD, and found (in a dark room):
With a black screen (no signal) I can initially detect backlight at about 10-15 degrees and it is significant at >45 degrees.
With normal programming I begin to detect loss of saturation and contrast at about 30 degrees, and it is quite noticable at 60 degrees.

So, can you watch a LCD from the side? Yes . . . and . . . No - depends on the angle.
Is LCD worse than Plasma for off axis viewing - most likely, yes.

robox4

I thought I read somewhere that some manufacturers have started using led technology for backlighting in LCD's. That's pretty impressive. When I think of LED, I think of tiny red and green "glow lights" for on/off switches and such. I had no idea they could get that kind of brightness out of an LED.

billinprinceto

Yes, that's a whole new topic. Must admit I have not been following it closely, but . . . .

I too recall having read a few things about using LEDs for backlighting, they can be pretty bright compared to the old ones. Example, check out the little LED flashlights that you can get at the hardware store these days - bright enough to hurt your eyes and the built-in batteries last forever. Impressive technology.

Also, LEDs are being used for giant display screens (up to 5' high by 14' wide at last count) for arena use. And TVs up to 140" - check it out: http://gizmodo.com/gadgets/ceatec200...tec-305961.php

billinprinceto

Well, we know that NOTHING lasts forever, so this would be a misconception about just about everything.

However, the LCD display itself will last pretty close to forever in human terms. Sort of like a transistor - will they fail? Yep. In your lifetime? Probably not. LCD display lifetime is probably in the millions of hours . . . which is close enough to forever for a consumer electronic product.

Now, the fluorescent backlight is a different matter. On average, they do indeed have a lifetime (actually a half life) of something on the order of 60,000 hours. And, most backlights can be replaced.