Subscribe / Unsubscribe Enewsletters | Login | Register

Pencil Banner

OLED vs LED: There's just no comparison

Jon L. Jacobi | Jan. 26, 2016
A simple explanation of the technology used in OLED TVs (and how it compares to LED-backlit LCD TVs).

eg9600 750x480 lg oled
Credit: LG

Okay, that’s a trick headline. There’s no comparison between OLED TVs and LED TVs because there’s really no such thing as what has been marketed as an LED TV. That’s just another case of the TV industry using misleading nomenclature to confuse consumers. What TV manufacturers have been advertising as LED TVS are just LCD TVs that use LEDs for backlighting.

Where an LCD TV produces color by shining the light produced by LEDs through color filters, an OLED TV uses LEDs that generate both light and color. The term organic comes from the materials used being carbon- and not silicon-based, which sounds touchy-feely, but doesn’t put them in the same class as lettuce or free-range chicken.

How OLED works

OLED's magic comes from electroluminescence. Basically, an electrical charge stimulates an electroluminescent substance that produces the desired color: red, green, or blue. The OLED itself is more or less a glass sandwich with a cathode and an anode (negative and positive terminals), plus two organic layers that transport electrons, and a middle layer that emits light.

cross section of amoled layers of an oled architecture 
The basic structure of an OLED. (Click to expand). Credit: LG

Because the OLEDs and the micro-circuitry matrix driving them are really all that’s there, an OLED display can be amazingly thin: LG showed an OLED TV at CES that was just 0.1 inches thick. And when OLEDs are applied to a flexible substrate, you can bend them, shape them, and even roll them up; well, this has been publicly demonstrated, but the flexible thing remains an elusive commercial entity. Transparent OLED panels have also been publicly show; again, cool but not quite ready for school.

Though the OLEDs in TVs are tiny, an OLED doesn’t have to be. You could make an entire wall from a single OLED, and there are lighting applications where a similar approach is not only feasible, but being done.

samsung display 55 inch transparent oled 1 1 
A 55-inch transparent OLED screen. Credit: Samsung Electronics

The OLED advantage as it applies to TVs

Aside from super thin and flexible, the fuss over OLED TV is stirred by their impressive picture quality. OLEDs turn off and don’t leak light as LCDs do, so you get a genuine black which makes for excellent contrast ratios. It’s a much more luxurious picture than your average LED-backlit LCD TV. I think of it as cashmere versus common wool.

Note, however, that I said average. New technologies such as quantum dots (aka nanocrystals) have improved the color in high-end LCD TVs. And HDR (high dynamic range), or increased contrast ratio via super brightness, is also making its presence known (though at the expense of increased power consumption).

 

1  2  3  Next Page 

Sign up for MIS Asia eNewsletters.