Response to APPLE INSIDER Post on the Microsoft ZUNE
September 16, 2009
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.
Some questions remain:
1. Why would Microsoft choose an OLED for its Zune? Could it be that OLEDs are
· Thinner and Lighter – The display is only 1 mm thick
· Faster – The response time is 5 µsec compared with 5 msec for the best LCDs. There is no blurring or shadowing on the fastest images
· Better in color gamut – OLEDs operate at >100% of the NTSC standard, while LCDs for small displays operate at <100% of NTSC
· 1000x better than the contrast of LCDs – Most films, TV and camera images operate at an average of ~20% of saturated colors, i.e. relatively dark, so contrast ratio as defined by black levels is significant for viewing purposes. In bright sunlight reflective devices only produce <15% contrast ratio.
· More efficient – ~50% of the power for the applications used on the Zune and the iPod.
· Virtually perfect image reproducers at wide viewing angle – while LCDs could lose up to 90% of their contrast ratio
2. Why would Microsoft choose a dark environment to demonstrate the OLED? Because it looks so good!
3. Why would Prince McLean write about something that he obviously has so little knowledge? Could it be that the Apple Insider is trying to curry favor with the Apple management so it can become an even deeper shill? It has become a popular art to predict what Apple is going to do and the company is very careful to keep its information on new products, closely held, so McLean may be hoping to get better access. I did not comment about the “Other Myths” in McLean’s article but if they are anything like his comments about OLEDs, you can draw your own conclusions about their relevance.
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.”