Understanding OLED TVs

image

What's more important, picture or pixels?


Oct. 31, 2012 — by .(JavaScript must be enabled to view this email address)

Ultra HD (4K) may be getting all the attention now, but OLED TVs promise good things too.

Back in January at the Consumer Electronics Show, LG Electronics and Samsung showed off some of the first commercially viable OLED TVs, 55-inch models sizes appropriate for home theater or media rooms (Sony briefly sold an OLED TV, but it was only an 11-inch model). Sony showed a prototype of a different technology called Crystal LED and is partnering with Panasonic to make OLED TVs in the future. We expect a couple sets from LG and Samsung to start hitting the market over the next 12 months, maybe sooner.

So far no manufacturer has revealed pricing plans, but considering that the 11-inch Sony TV was $2,500 in 2008, we expect the first 55-inch TVs to be around $10,000 (plus or minus something), which puts them north of the highly rated Sharp Elite LED TVs. Whatever they cost, we expect them to be awesome.

How It Works:
TVs need light. Plasma TVs produce light from an electric charge exciting the gas to make a phosphor layer glow. Conventional LCD TVs use either CCFL or LED backlights. CCLF lights can’t be turned off, so the images always look a little washed out. LED backlights can be somewhat locally dimmed, but the results aren’t perfect.

AN OLED TV uses a layer of light emitting material within the panel in which the light-producing part is composed of an organic matter, such as carbon.

While there are several applications for OLED, in televisions the method uses in LG’s upcoming 55-inch TV is based around a stacked architecture in which RGB OLED layers are arranged on top of each other and behind a color refiner (like a color filter).

A thin film transistor backplane on glass provides the circuitry to power the OLEDs and creates the 1920 x 1080 resolution structure. Due to the extremely thin profile of the TVs, separate input boxes are likely to be needed to connect source components.


What are the benefits of OLED

• Energy: Just as LED TVs consume less energy than CCFL or plasma TVs, OLED TVs consume even less. This means that a whopping big TV may only require a trickle of power to operate.

• No backlight: Just like a plasma TV, an OLED TVs is self-emitting, which means the TV doesn’t require a back or edge lighting mechanism (with plasma TVs, the plasma gas produces the light).

• High contrast: Extremely high contrast is possible because individual pixels can be completely turned off, which is something no LED TV can do, even with local dimming. Preproduction samples we’ve seen demonstrated outstanding black levels, possibly the best achievable.

• Brightness: We haven’t tried any ourselves outside of trade shows, but so far they look extremely bright. Manufactures have been vague on light output specs, but numbers like 100 foot lamberts have been floated.

• Wide angle: Because the image is not passing through a crystal, the viewing angles would be as good as plasma or CRT TVs.

• Thin: OLEDs use fewer materials or layers, which means the TV itself can be incredibly thin and light. LG has demonstrated a 55-inch OLED TV that’s only 4mm thick. In the future, OLED TVs may even be flexible.

• Speed: OLEDs have the potential to be the Usain Bolt of the TV world, being the fastest TV technology ever. Refresh rates up to 100,000 Hz are theoretically possible.


Samsung OLED TVs shown at the 2012 CES



Return to full story:
http://www.electronichouse.com/article/understanding_oled_tvs/P1526