The OLED Association has answered Prince McLean’s article on Apple insider titled From OLED to Tegra: Five Myths of the Zune HD. Some spot-on points can also be read on my previous post on Zune HD and OLED screens. Coincidentally, both article was published last September 16. (only saw this now)
The “Apple Insider”: a Display Outsider or an Apple Shill?
On Monday, Prince McLean released a blog post titled “From OLED to Tegra: Five Myths of the Zune HD.” I won’t comment about the other 4 Myths but his comments about OLEDs demonstrate a complete lack of knowledge regarding the performance, specifications and use of flat panel displays. He makes several erroneous statements about OLEDS, including:
First OLED myth: “OLEDs are dimmer that LCDs because the luminance is only 200 cd/m2, while LCDs have luminance of 400-500 cd/m2.”
LCDs TVs have luminance of 4-500 cd/m2, but displays on mobile devices is typically 200 to 250 cd/m2. The display on the Zune is spec’d at 250 cd/m2 before the addition of the touch features. Moreover, it has been demonstrated by Samsung, a TFT LCD supplier, that OLEDs at 250 cd/m2 have the same perceived brightness at TFT LCDs at 400 cd/m2.
Second OLED myth: “A good quality LCD actually uses ambient light to make its image brighter and more vibrant; OLED does not.”
Mobile devices often use transflective LCDs, which operate in two modes, (1) a reflective mode in which the backlight if off and (2) a transmissive mode, in which the backlight is on. Both modes are compromises but serve the market well. OLEDs, which are emissive devices, use higher luminance to overcome the effect of high ambient conditions. Again, Samsung reports that OLEDs at 300 cd/m2 will outperform any transflective LCD is bright sunlight.
Third OLED myth: “There are other problems with OLED. They don't last long, because the electroluminescence layer degrades far more rapidly than regular LCDs.”
The OLED display in the Zune has a lifetime of 50,000 hours. Typically LCDs for mobile products are rated at ~25,000. However, none of this is very important – These types of products have a useful life of 5-years, which at 8 hours/day and 365 days a year is only 15,000 hours; well within the capability of either technology.
Fourth OLED myth: “And despite the power savings attributed to OLED's backlight-free design, OLEDs still use more power than LCD displays most of the time because the OLED technology consumes power based on how bright the image it is displaying is. Essentially, OLED is the backlight”.
It has been demonstrated and documented by Nokia that when the application is video or imaging, OLEDs use less than ½ the power of a comparable TFT LCD. McLean’s comment that the OLED is a backlight just demonstrates his lack of knowledge about displays. Emissive displays (OLEDs, PDPs) do not require backlights as they emit light without the need for an external source of light. If the image is black, i.e. the UI for the Apple iPod or the iPhone, an OLED uses almost no power, while the LCD uses maximum power under all conditions. The situation is so bad that LCD TVs are being designed with 100s of LEDs at high cost to implement local dimming to reduce power consumption.
Finally, I wonder how McLean would respond to the quote by Steve Jobs, when his display technologists showed him OLED displays for the first time, “that’s the best f----n display I have ever seen.”
full article taken from www.olded-a.org