OLED Displays

OLED (organic light emitting diode) displays will replace LCD displays. Here are the reasons why and the things you should check before buying OLED.

Current OLED displays are small but fit the MP3 player market. 2004 saw over 30 million OLED displays go in to over 60 different MP3 players and similar small devices. Production will double every year for the foreseeable future.

Fake Display Images

You will see lots of pretty OLED displays in photographs but do not believe what you see. Display manufacturers have long established the protocol of faking the display.

CRT displays have limitations that make the displays hard to photograph. Instead of finding a competent photographer, the advertising agencies simply insert a fake image into the image of the display. The advertising agencies follow the same protocol for LCD displays so expect the same for OLED displays.

Based on observing advertising agencies at work, some use the following logic. They can get a local competent photographer to produce a useable image of a display for between $600 and $1,000. They can get a work experience kid from the local arts college to photograph the image for $300. The $300 photograph will then need 20 minutes editing from a $150 per day Photoshop work experience kid. While they can bill the $300 photograph out to their customer at only $2,000, they can bill the $6.25 worth of Photoshop editing out at $6,000.

The result is, of course, fake, and looks fake, but is far more profitable to the agency. The agencies claim that everyone else does it therefore they have to do it to keep up with the other agencies. First time buyers believe the images and sales increase for a short time. After that first boost, everything else is based on word of mouth and live displays in shops. If your product does not look exactly like the fake created by the advertising agency, you lose sales.

As a buyer, ignore every image in print because it is most likely fake no matter what the surrounding text says. Go in to a store and see the display live. Make sure you see the display in the same conditions that you will use the display. If you are buying a phone or notebook that you will use outdoors, try the OLED display outdoors before you buy.

The perfect Picture

There are beautiful high resolution OLED displays but they require an expensive manufacturing process and one company, Eastman Kodak, owns all the patents. Most OLED displays use a cheaper manufacturing process that produces images similar to low quality LCD screens.

The good news is that cheap OLED screens are improving faster than LCD screens and will replace LCD screens by the end of next year.

Better Battery Life

LCD displays burn power in their backlights. The backlights produce pure white light full on all the time then the LCD screen reduces the light to produce darker colours. OLEDs are the reverse. OLEDs burn power to produce white but use less power when they need produce only red or blue or green.

If you view black text on a white background, OLEDs use as little as 70% of the power used by an LCD. When you read a Windows blue screen of death, with white text on a blue background, you are using only 30% of an LCD's power. When you struggle with white text on a black background, as used on some primitive Unix machines and Web sites, you use as little as 10% of an LCD's power.

You can now see why OLED users choose coloured text on a black background. The colour scheme would not save power on an LCD screen but it does wonders for OLED. Considering that the display of a handheld device can use twice as much power as everything else in the device, the power saving of the OLED could triple battery life.

Display Life

Current OLED displays are lucky to last 5,000 hours. If you use OLED in a mobile phone (cell phone) that is on for 2 hours per day, you will get 7 years use from the display which is several years more than you will use the phone.

Our desktop computer displays are on for far longer per day. I work from home so use the same computer for work, playing DVDs, and watching the news on television. My computer is on 20 hours per day up to 6 days per week for up to 50 weeks in a year. I need a display that will last 30,000 hours.

LCD displays fade. If OLED has the same fade then you will need an OLED display with a design life of 60,000 hours to get a decent display for 30,000 hours.

The latest generation of OLED displays can last 50,000 hours and may be in the shops next year.

Display Quality

Contrast

Some aspects of OLED displays are better than LCD displays. LCD works by filtering white light. LCD has a problem displaying black because LCD cannot completely block the white light. OLED emits only the light needed so black should be easy to create.

LCD is not completely transparent when producing white which means that white is just light grey. You get white from LCD by making the white backlight overbright to compensate for the LCD's grey. OLED does not have the messy polarising filter system used in LCD which should mean that OLED white is crisp clean white.

While LCD displays struggle to produce a contast of 500:1, OLED can produce 5,000:1; which is 10 times better.

Colour Range

OLED display quality should match CRT display quality because they share the feature of direct light emission. OLED does not need a vacuum or that heavy glass enclosure used in CRT displays.

Computer screens display 24,000,000 colours. Many phone and handheld device LCD displays are limited to 65,000 colours and some premium LCD screens produce 256,000 colours. The very latest premium LCD screens produce 16,000,000 colours. OLED currently displays up to 16,000,000 colours and, hopefully, will soon reach 24,000,000 colours.

Accuracy

LCD also does a poor job of reproducing colours that are close to black or close to white. OLED might have the same problem if the light produced by OLED is not linear in response. The current biggest problem is that blue and red OLED elements produce light at different efficiencies. Once the OLED blue, red, and green elements are all equally efficient, OLED will match the colour range of CRT displays.

Blue OLED is the main problem. Blue OLED is weaker than green or red OLED. Early in 2009 PNNL, Pacific Northwest National Laboratory, announced a blue OLED approaching the efficiency and brightness of green OLED. Blue might not be a problem in the future.

Guarantee

LCD displays are often sold damaged. LCD manufacturers think it is acceptable to sell broken displays so long as it is not too broken. When you buy an OLED display, demand a zero pixel error guarantee. If everyone refuses to buy rubbish displays then the OLED manufacturers will have to revert to the higher standards that applied to CRTs.

Examples

Updated 2009
The Nokia N86 uses a 2.6" OLED display.

LG demonstrated a 15" OLED at the 2009 CES. The screen, at 1.4mm thin, makes those thin Apple products look chunky. LG claim the lifetime is 30,000 hours.

UDC delivered a prototype flexible OLED you can wear on your wrist. The version for the American Army display green during the daytime then switches to infrared at night so that soldiers can read the display through their IR goggles without the other team seeing the display.

Who owns OLED?

Updated 2009

Several companies control the current OLED market and their older patents are running out, opening the way to mass production at low prices in China.

Eastman Kodak Company

Eastman Kodak Company led the market with fluorescent OLED technology licensed to many manufacturers. Fluorescent OLED technology has one main advantage, it was first into large scale manufacturing. Kodak invented OLED 40 years ago so you would expect it to be first. Kodak sold the lot to LG. Expect displays from LG that are almost as expensive as Samsung displays but without the quality or testing.

Cambridge Display Technology Ltd.

Cambridge Display Technology Ltd., now owned by Sumitomo Chemical Company, licenses polymer OLED technology to manufacturers.

Motorola

From Universal Display Corporation 2008 annual report:
In September 2000, we entered into a License Agreement with Motorola whereby Motorola granted us perpetual license rights to what are now 74 issued U.S. patents relating to Motorola’s OLED technologies, together with numerous foreign counterparts in various countries. These patents will start expiring in the U.S. in 2012.

Motorola owns part of OLED until 2012. We can expect OLED to become cheaper as those and other patents expire.

Seiko Epson

Seiko purchased some licenses from Universal Display Corporation and developed an inkjet printer that can print huge OLED screens. They will be the first to market with economical large screen OLED televisions.

Universal Display Corporation

UDC, Universal Display Corporation, sells PHOLED OLED and licenses it to Samsung SMD, Seiko Epson, and others.

Conclusion

OLED is a replacement for LCD displays in devices where the display is mostly off. Before you buy OLED for a television or a regular computer display, make sure the display will last at least 30,000 hours.