Samsung poised to introduce white LED-backlit displays

Samsung believes that by 2010, 30% of all LCD televisions will include LED backlights instead of the conventional flourescent used in most sets now. What's different from the LED units we've seen before is that Samsung wants to use white LEDs, with single diodes custom-coated to produce the same backlight previously requiring combinations of red, green, and blue bulbs. Samsung recently invested in Intematix, which produces custom phosphor coatings for LED bulbs to create uniform color -- required in a television to faithfully reproduce colors. Until recently costs have been higher for LED backlight units, keeping them relegated to higher-end models. Samsung claims the single bulb process reduces costs by 40%, but time will tell whether white-only LEDs are truly better or cheaper than tri-color LEDs, or if they are just the next "Reveal lightbulb" marketing gimmick.

[Via I4U News]

[aeo @ May 14th 2007 4:33PM]

LED backlit LCD's scare me a little in that although they're really really cool, I'm worried that now there's the possibility of 1 LED going out leaving a dark spot on the screen. Manufacturers have "dead pixel" policies, I wonder what a dead LED policy will be like? Think the LEDs will be maintainable individually or will they require a complete module swap?

[spam_from_engadget @ May 14th 2007 6:22PM]

I know some people who made some cavers' headlamps using some of the first super-bright white LEDs to come onto the market. They had a reliability problem because they underestimated the amount of heat-sinking requied; the LEDs will seem to work fine when they're hot, but the temperature will deform the bond wires or the substrate until they fail. I imagine that this is the sort of thing that another poster is describing in traffic signals.

I would hope that this sort of problem would be avoided in a monitor design. The essential point is that the basic light-emitting technology is itself very reliable; about as reliable as a transistor probably.

[Mobi Fin @ May 14th 2007 4:43PM]

@aeo - the LED's have an expected life of 80 + years. You'll be long dead by then so don't concern yourself with it.

Samsung is an awesome company - I love those guys (and their models)

[Alex @ May 14th 2007 4:49PM]

LEDs are very reliable and last a very, very long time. You shouldn't ever have to worry about an LED bulb going out on you. If you receive a screen with a dead LED, there was probably a manufacturing issue, rather than the dead LCD pixels that are almost an expected part of the technology.

[Realist @ May 14th 2007 5:30PM]

According to the Department of Energy, high-power white LEDs have an estimated useful life somewhere between 30,000 and 50,000 hours or approximately 4 to 6 years (not 80+ years). From a more realistic point of view, drive around town and observe the frequency of dead pixels in LED traffic signals. Since these are typically based on tried-and-true red/green LEDs, you will see that there is reason to be concerned about the details of a companies "dead pixel" policy -- even if the problem is in the manufacturing of the LED panel. Most policies allow for both a total number of allowable dead pixels with an maximum number of adjacent pixels. I would suspect that a single dead LED will be much more obvious than a single dead LCD pixel. It's definitely worth knowing the details of any specific policy before making a purchase.

[Jeff @ May 14th 2007 5:07PM]

What I would like to see is a replacement LED bulb for my DLP television. With an LED bulb, I won't have to pay over $300 when my bulb goes out again. New TV's are great, if you have the money for them. I would rather pay out the money for an LED bulb for my current DLP HDTV.

[Castle @ May 14th 2007 5:07PM]

I have a LED backlit LCD on my Toshiba R400, its certainly brighter the conventional displays, however, Its pretty subtle. If I wasn't told it was LED backlit I wouldn't have guessed.

However, as white LEDs start getting cheaper (white is still relatively expensive); I'm sure a lot of companies will start using LEDs for back lighting in the future.

[Rob @ May 14th 2007 5:15PM]

@Jeff - Samsung already sells an LED-based DLP set (several actually). I have one, and it's great. It's not as simple as swapping out a bulb, though. The standard bulb DLP uses a white light that gets its color from the spinning color wheel, which then hits the DLP chip. In the case of their LED sets, they actually have separate Red, Green, and Blue LEDs which shine directly onto the chip. So there's no color wheel at all. Not to say someone won't someday come out with a white LED replacement bulb for a lamp-based DLP, but that doesn't appear to be the direction that (at least) Samsung is going with LED technology.

[Alex @ May 14th 2007 6:12PM]

Although I agree with your statement about dead pixels, I would assume that it would be the equivalent of a dead backlight in this case. The manufacturers have to realize that a single dead LED would be a significant problem and be covered under warranty, much lick a current backlight would be. However, regarding the lifespan of an LED, you're misrepresenting the data. If I used my computer for 24 hours a day then, yes, an LED lifespan of only 4 years would be terrible. Thankfully, since most people don't even use their computers for more than 6 hours a day, they can expect 16 or more years from their LEDs.

[Alex @ May 14th 2007 6:15PM]

Sorry Realist, I got your reply in my email and didn't see the other post you were referencing regarding the LED lifespan. You were right in correcting Mobi Fin, I thought it was directed at me.

[Russell @ May 14th 2007 7:56PM]

The problem is most TV's "warranty" is only for a year to three years. You should still be able to expect it to last 10+ not have 90% of them have failure at 5 years.

[shimman @ May 14th 2007 7:54PM]

white led will make bit cheaper & less power hungry, i think.

however, the quality of white led is the key for the improving color on lcd panel.

the trade off for white led is the led life which would be similar to cf although can be used in colder temp without loosing too much life out of it.

this could be a great move for samsung

[Jacques67 @ May 14th 2007 8:53PM]

"White" LEDs have poor CRI in comparison to a RGB-White diode (they are, at the most basic level, blue LEDs. The phosphor coating is excited by blue wavelengths and emits red and green (i.e. yellow) light, creating white). These phosphor coatings have to be VERY, very advanced in order for them to output full spectrum white. Perhaps this Intematix company has figured it out, though I doubt it. Fluorescent bulbs aren't even 100 CRI and those have been around, and improved upon, several times longer than phosphor-coated LEDs.

So far:
Halogen Incandescent bulb: CRI 99
Full Spectrum CCFL: CRI 91
Fluorescent lamp: CRI 70-90
White LED: CRI 60-80

And "GE Reveal" bulbs aren't a gimmick, Engadget. Any good photographer will know what an 80A filter is, cinematographers know what CTB Gel is. They are both transparent light-blue filters that reduce the orange-yellowish light that come off of incandescent bulbs. GE Reveal bulbs have this built in (though they are not nearly strong enough due to efficiency's sake; a full CTB Gel cuts back 2 stops of light!)

[Jeff @ May 15th 2007 10:16AM]

@Rob...

Yeah, that is what I want, an LED bulb for my existing DLP set. I don't really want to go spend thousands of dollars on a new set, when I enjoy my 62" DLP very much. I just want a white LED replacement bulb for my DLP set.

http://thewarp.org/blog/index.cfm/2007/5/14/DLP-replacement-bulbs--Where-are-the-LED-replacement-bulbs