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News ASA bans Samsung LED TV ads

Discussion in 'Article Discussion' started by CardJoe, 3 Sep 2009.

  1. lcd-guru

    lcd-guru What's a Dremel?

    25 Dec 2009
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    All said and done, the term LED TV is a misnomer and the average consumer is easily misled into thinking that it is some new technology that promises quantum leaps in clarity, contrast, vividness of colors, great viewing angles etc. Color TV is a mature industry in a marketplace that is becoming ever more crowded - with new upstarts jostling for standing place with old timers and not-so-old timers. Profits for TV manufacturers have become razor-thin and, even negative for some. Hence the sheer desperation to find something to attract consumer interest -- even deploying the occasional hoodwinking via misleading information. After all who cares if the consumer finds out that his newly acquired "cutting-edge tech" LED TV is indeed the old LCD TV with a backlight that is lit by a bar of white LEDs instead of the usual CCFL ? The important thing is : the manufacturer has succeeded in persuading the consumer to part with his money - mission accomplished.

    In reality, an "LED" TV may not always be superior to a conventional CCFL backlit LCD TV. Unknown to most people outside of the industry, it is extremely difficult to make consistent LEDs in white. There is a huge range of fluctuation in terms of brightness and color tinge in any production batch of white LEDs. Though there is a standard sorting procedure used by LED mfrs to grade brightness and color tinge (called variation in color coordinates), in reality every LED in the backlight array is different. Out of 100,000 TVs made, perhaps there is only one or two that would have the perfect LED backlight. From one end of the TV screen to the other, there will be bound to be variations in brightness and color tinge. And the brightness variation problem will get worse as time goes on, because as lower grade LEDs in the array are driven harder to compensate for their inherent lower brightness, their lives get shorter than the higher grade ones. Even this leads to uneven brightness across the screen.

    In any batch of production of white LEDs, the range of so-called acceptable grades is really small, no more than 50% at best. This often leads to a supply crunch, as the other TFT LCD applications such as mobile phones and increasingly, monitor screens and notebook pcs, compete for white LED supplies. When push comes to shove, inevitably, TV manufacturers will have to compromise and start widening their "acceptable range" of grades. This eventually appears as less-than-satisfactory displays in the TVs.

    It is claimed that "LED TVs" have higher NTSC color gamut, but this is again doubtful unless the display screen under test has that perfect backlight. Also, the color filters on the TFT LCD that makes up the screen are still the predominant factor in rendering color vividness. So dont be taken in so fast yet.

    Apparently the main advantage with LED backlighting appears to be that it is more "green" and thus more environmental-friendly than the CCFL type. There are hazardous materials used inside the CFFL coatings and the mercury vapor that fills CCFL is also poisonous. Plus CCFL needs special electronic circuits called invertors to get them to light up. However, for the whole equation to be considered valid, one needs to evaluate the production of white LEDs in detail. They still need a special fluorescent coating that converts the original blue light from the LED dice into white, plus special white LED driver ICs are needed to drive the finished LEDs. Time will tell all if it is all that green.

    Talking about mobile phones, everyone of them has an LED backlight, strangely nobody calls them LED displays or LED phones !

  2. _Metal_Guitar_

    _Metal_Guitar_ What's a Dremel?

    16 Jun 2009
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    There are three types of LED backlighting, two of which use white LEDs. But you can also can get dynamic RBG LED backlite TV's which do offer better contrast, as, well, they are dynamic. Also, whites are better, the RBG combo gives a pure white light. Given the fact that it is fairly obvious when samsung advertised LED TV's, that these were not OLED screens, I think it would be far more prudent to tell people what kind of LED backlighting they are getting.
  3. MSHunter

    MSHunter Minimodder

    24 Apr 2009
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    +1 to you as this is the exact problem you face when Buying a new TV if it says LED on the box you have offten no way of finding out what type of LED is being use. I could only find a few TVs that use RGB LED lighting by reading through Chip.de (german site) listing of top 100 LCD TV's and geuse what ONLY TWO TV's used RGB LED's
  4. azrael-

    azrael- I'm special...

    18 May 2008
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    FINALLY there's a governmental agency calling Samsung's BS on the matter of "LED tvs"!

    I've been utterly annoyed about this term ever since Samsung first introduced it. It's been a deliberately misleading lie from the outset. I wish the Danish counterpart to the ASA would get some balls and do the same.

    EDIT: I see this was originally reported back in september 2009. Must've fallen through the cracks in my browser back then. :p
    Last edited: 2 Jun 2010
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