LED TV Technology

philips-led-backlighting

When we first started our podcast there were five competing technologies vying for your living room. Today its pretty much down to LCD and Plasma. Most would say LCD is running away with the market but Plasma is hanging in there. So what about LED? LED is not a new TV technology but rather a different way to light the LCD. A Liquid Crystal Display is a glass panel that works by controlling the opacity of segments of itself by varying the electrical signal. Each individual segment, called a pixel, acts as a shutter to control the amount of light being passed through. The light source is what we will be focusing on today.

Today’s Show:

News:

Other:


LED TV Technology

When we first started our podcast there were five competing technologies vying for your living room. Today its pretty much down to LCD and Plasma. Most would say LCD is running away with the market but Plasma is hanging in there. So what about LED? LED is not a new TV technology but rather a different way to light the LCD. A Liquid Crystal Display is a glass panel that works by controlling the opacity of segments of itself by varying the electrical signal. Each individual segment, called a pixel, acts as a shutter to control the amount of light being passed through. The light source is what we will be focusing on today.

Background

On current LCD TVs, fluorescent lights are used to back-light screens. You may have seen the acronym CCFL, it stands for Cold-Cathode Fluorescent Lamp and these types of lamps can even be used to light your home. To back-light TVs, a series of these lights are laid horizontally across the back to the TV.

File1

There is typically a plastic sheet in front of the light which will distribute the light evenly onto the glass panel. One of the difficulties in LCD TVs is creating true black. The reason for this is that the light is always on. To darken a screen the light must be blocked and as hard as manufacturers try some light bleeds through.

LED

LEDs have recently become a popular means for lighting LCD screens. Some of the advantages for moving to LED are size, power, and image quality. LEDs are smaller than the CCFL tubes and they use less energy. A side benefit of using less energy is that the TV produces less heat which can extend its life. Better picture quality depends on what style of LED lighting is used.

There are two styles of LED lighting, edge or direct mount. Edge lighting, as the name implies, arranges the LEDs along the edge of the panel. Because the LEDs are mounted on the edge the TVs are much thinner. The light is channeled behind the glass using guides to provide even lighting. The disadvantage of edge lighting is that you can not use local dimming to increase the TV’s contrast. You still get the energy and size benefits however.

File2

Direct lit LEDs place the LED behind the glass. There can be as many as 1500 LEDs (depending on the size of the TV) placed in an array to light up the slightly more than two million pixels of your 1080p TV. Each LED can be responsible for almost 1400 pixels (or more on smaller sized TVs). The main advantage of the direct lit LEDs is that the TV can use local dimming. That means if an area of the screen is dark the LEDs can be turned off thereby increasing the contrast.

File3

Because the LEDs are behind the glass they are not as thin as edge mount LEDs. There are two types of direct lit LEDs, White and RGB. White LEDs are simlar to their CCFL cousins in that they produce white light. The Samsung UA40B710 is a TV that uses white LEDs. RGB LEDs use three colors (red, green, and blue) which make TVs with this kind of light capable of a broader color range. Those who favor this type of LED say that there is less green push. Sony uses RGB lights in their BRAVIA LED TVs.

Some things to consider

  • LED color consistency – It is difficult to make LEDs in consistent white color and this may affect your picture. Manufacturers will not take back a TV because the color is slightly off. You could try to return it to BestBuy until you get one that is perfect.
  • Some Edge Lit TVs have uneven lighting. Again try explaining to the manufacturer that the TV lighting seems uneven. You can also do the Best Buy thing with this one too.
  • Reliability? We’ve all seen the LED traffic lights that were supposed to last for 20 years without needing replacement. I stopped counting how many signals have multiple failed LEDs. Will our TVs suffer the same fate?
  • Price – Right now you are paying a premium for buying a TV that has a picture that is close to what plasma has always had.


HT Guys

HTGuys.com

Wearables

To be blunt, the Vuzix Blade smartglasses just don’t cut it

We tried out the Vuzix Blade to find out if it’s worth shelling out $1,000 for smartglasses. Are these augmented reality, Android-powered glasses really ready for primetime or just an expensive gimmick that no one really needs?
Product Review

Canon democratizes full-frame with the EOS RP, but keep your expectations low

At just $1,300, the RP is Canon's least expensive full-frame camera yet, but it was born into a world of high-end, high-cost lenses where it doesn't yet feel at home.
Home Theater

8K TV: Everything you need to know about the future of television

4K TVs may seem relatively new, but there's another even higher-resolution display technology already here: 8K TV. Should you upgrade? We've got the answers to that question and more.
Mobile

Avoid scratches and dents with the 20 best iPhone 8 Plus cases

So you've got a new iPhone? Congrats! But with a glass design, and looks to die for, you'd best keep it safe. Not sure about the best case choice? Check out our guide to the best iPhone 8 Plus cases for some great ideas.
Product Review

Focal’s ultra-clear Sphear Wireless bring sexy back to banded Bluetooth buds

Focal’s Sphear Wireless are a sleek and simple pair of banded Bluetooth earbuds with exceptional sound and an affordable price, making them some of the only non-true wireless earbuds we’d consider buying right now.
Home Theater

Apple will reportedly launch its new video-streaming service at March 25 event

The rumors about what Apple will announce at a March 25 event continue to swirl. A new report suggests that it will debut its much-anticipated video-streaming service, which will compete with Netflix and Amazon's Prime Video.
Home Theater

Bose’s technology patents could save an earbud’s battery life

Possibly taking a cue from Apple's popular AirPods, Bose filed a patent application for earbud IR technology that could save battery life, improve sound quality, and possibly help people locate lost earbuds.
Home Theater

ATSC 3.0: The next-gen TV update explained

ATSC 3.0 is the next major update to the broadcast standard we use today. Will this be the second coming of free, over-the-air TV? We're here to explain everything about the new standard.
Home Theater

Samsung accidentally leaks its new Galaxy Buds ahead of launch

It's been all but certain that Samsung would launch a successor to its Gear IconX wireless earbuds soon, but a newly leaked photo and recent FCC certification document seems to indicate that the debut is very close.
Home Theater

Hi-res streaming audio service Qobuz arrives in U.S., threatens Tidal’s monopoly

For several years, Tidal enjoyed a monopoly on hi-res music streaming in the U.S. Now, French company Qobuz is here to offer some competition with a variety of monthly plans starting at $10 a month.
Home Theater

Throw away those EarPods -- we dug up the best headphones in every style

Trolling the internet for hours to find headphones is no way to live. Instead, leverage our expertise and experience to find the best headphones for you. Here are our 10 favorites.
Home Theater

Still listening on tinny, muffled TV speakers? Try one of our favorite soundbars

You no longer have to sacrifice sound for size when selecting home audio equipment. Check out our picks for the best soundbars, whether you're looking for budget options, pure power, smarts, or tons of features.
Home Theater

Samsung will stop releasing new Blu-ray players in the U.S.

Samsung, the first company to produce a 4K Ultra HD Blu-ray player, is now exiting the Blu-ray market entirely in the U.S. The move comes after Oppo Digital also dropped out of the market last year.
Movies & TV

The Breaking Bad sequel might air on Netflix before it arrives on AMC

A Breaking Bad sequel starring Jesse Pinkman (and, possibly, Walter White) is on the way from series creator Vince Gilligan, and you might get your first look at it on Netflix, not traditional cable.