Earlier we talked about a new type of OLED (organic light emitting diode) called WOLED that is supposed to act as a kind of bridge between existing LCD and future OLED technologies. LG have recently announced a professional 5:4 20.7″ WOLED monitor intended for use as a ‘medical display’. An astonishing QSXGA resolution of 2560×2048 is coupled with a staggering static contrast ratio of >100,000:1 (remember – the pixels are all individually illuminated) and literally brilliant peak luminance of 900cd/m2 to give one extremely capable display. Although limited to such professional uses (and probably prohibitively expensive), LG hopes to further develop this technology for use on TV screens and PC monitors in our homes. You can read more about the so-called ‘White OLED Tandem’ technology and medical display here. The future looks bright for LG.

LG WOLED monitor (source: OLED-Display.net)

The Inquirer has published an interesting article about their experiences at two recent display technology presentation events; namely Taipei Display Expo and Broadcast Asia in Singapore. They were surprised to see manufacturers showing off monitors with 16:10 and 5:4 aspect ratios, instead of the now usual 16:9. They also noted seeing a nice selection of OLED monitors (as large as 17 inches) on display for the first time as well as a plethora of LED-backlit LCD displays of all sizes, panel types and resolutions. There were also some mighty and impressive 3D computer monitors and TVs on display at the events, including the enormous 65-inch AUO ‘pattern retarder’ 3D Full HD LED TV. Some 480Hz refresh rate technology was also shown off (although most likely not a ‘true’ 480Hz but rather using pulldown and frame rate conversation techniques). For more information about the display technologies shown off at the event, see the original The Inquirer has article.

Samsung recently attended and presented at the SID 2010 conference, with their focus on upcoming OLED technology. In part of his keynote speech, Samsung Mobile Display Vice President San Soo Kim addressed the improvements Samsung hope to make to OLED technologies in the near future. For a typical ‘large TV sized’ screen this included reducing maximum power consumption from 62W to <30W, doubling screen lifetime from >50,000 hours (over 5 years) to >100,000 hours (over 11 years) and using TFT backplane substrates to enhance the size and resolution of the OLED screen. The most important thing to take away from the conference is that Samsung envisages premium AMOLED TVs should be part of the mainstream market by 2015. Although computer monitors weren’t mentioned specifically, the technology is just as applicable to OLED monitors as it is TVs and the same challenges must be overcome. Read more here.

Samsung and others have been working hard recently to extend the life of the organic materials used in OLED displays (particularly those used to produce blue light). Meanwhile Russian physicists have been experimenting with the use of cadmium chalcogenide (whatever that is) nano crystals in place of the usual organic materials in OLED displays. This is supposed to increase the life of the materials “significantly” and could therefore potentially prolong the life of an OLED screen and prevent fading over time. We are not sure how much longer the nano crystals last and what effect that would have on the monitors lifespan; but any improvement is a good thing. Read more about these developments here.

I was asked a very short but interesting question over at the Overclockers UK forums yesterday – “…how good are OLED monitors going to be compared to existing LED [backlit] monitors?”. As this is a question many of you may be asking yourself, I’ll share the answer here.

The short answer to that question is that they’re on an entirely different level. Having seen demonstrations of Samsung’s OLED monitor technologies in Asia last year I can honestly say that it is an instant “wow – this is different” kind of experience. The overall image is just so much more natural looking and beautifully crisp and vivid.

Because they do away with the backlight and have nice coloured organic light emitted directly from the pixels themselves you have much greater control over the colour and luminance of each pixel. What this means is that instead of having a set brightness across the screen (or in areas as you get with some more expensive “local dimming” LED backlights) you have a set brightness for each pixel – some could be off to give the purest black, whilst adjacent pixels could be on to give the purest white and of course any colour in between. You can think of it as a kind of highly efficient, much higher resolution and flicker-free alternative to plasma.

Because there is no backlight, the colour gamut is dictated by the pixels themselves and is therefore exceptionally broad. It can also be much more tightly controlled than in existing technologies, yielding superior out-of-the-box colour accuracy. You also don’t have to wait for any filters to operate when producing colour so the response times are almost instantaneous (in the order of <0.01ms). The direct emission of light from the pixels, with only a few thin layers of material infront, means that the image has fine colour and contrast at practically 180 degrees.

The efficiency of OLED technology is being improved all the time, but some speculate that once they are widely available you could have a 24″ OLED monitor use around 1W of electricity for every 100cd/m2 of brightness (so 4W for a sustained 400cd/m2 brightness). This is oversimplified really, but efficiency is set to be a real strength of OLED technology.

Aside from efficiency; the manufacturing process itself is constantly being refined. New spraying processes, modified organic materials, thinner cathodes and TFT backplane materials can all improve the characteristics (and impotantly, lower the cost) of OLED monitors further. Hopefully in a few years time they will be ready for the mainstream monitor market and they will find their place for a multitude of applications – both professional and home uses.