OLED technology not optimal for ebook readers
By Paul Biba
I was in New York today for a press event that had nothing to do with TeleRead. While there I passed by the booth from the OLED Association. Since OLED displays are absolutely gorgeous, I asked the representative about using them for ebook readers.
He said that given the current way ebooks are presented OLED would not be an optimal technology. While OLED is extremely battery efficient compared to LED screens, it wouldn’t work well for ebooks. This is because OLED’s battery efficiency comes from the fact that only the driven leds require power. Black pixels, for example, draw absolutely zero current. So, since people like to read on a white background, all those white pixels will be drawing current to produce the background, and the relatively little space devoted to the black text would draw no current. Not very efficient. He said that if people wanted to read white text on a black background then OLED technology would be just perfect in terms of battery life.
April 29th, 2009 at 9:45 pm
I love to read with white text on black background because it is easier on my eyes. I use this color scheme in my terminal windows, on my PDAs and even in browser windows sometimes. Please make an OLED book reader!
April 29th, 2009 at 9:50 pm
While the above statement does make sense in isolation, I don’t think it does when you compare OLED to LED or other displays. Yes, driving all RGB OLED elements to create white will obviously draw more power (just as with LED). But I understand that OLED is still more efficient that LED overall.
His statements also ignore the fact that many people want a color display, which isn’t currently available with eInk. Even when reading in pure B&W, you don’t need to run the display at full brightness. On LED displays with a backlight, I always turn things down, as full brightness is way too much for me.
Since there are lots of people reading on LED displays now (PDAs, netbooks, laptops, etc.), why wouldn’t we want a more efficient OLED display to conserve battery power?
For example, my Asus 1000HE netbook with a conventional LED display gives me about eight hours of continuous use. Now, this is running a full OS on an Intel Atom with all the netbook bells and whistles. An ARM CPU on a dedicated ebook reader is bound to run for substantially longer.
While I can agree that OLED may not currently be the optimum display technology for ebook readers, I think dismissing its use entirely is short sighted. Many of us have been using sub-optimal technologies to read for years. There is a concept known as “good enough”.
So, tell me again, why aren’t OLED displays not suited for ebook readers?
April 29th, 2009 at 9:51 pm
Whoops. In the above, I meant LCD, not LED displays.
April 29th, 2009 at 10:25 pm
In the 1970s and 80s the cathode ray tube (CRT) terminals attached to computers would typically display light-colored text on a black background. The text was often green, amber or white. Computer programmers of that era spent hours reading program code and text displayed on a black background.
When bit-mapped terminals became more common in the 1980s and 90s people began switching to black text on white I think. The preference might be based more on cultural selection than perceptual enhancement.
April 30th, 2009 at 7:18 am
What? People actually prefer reading black-on-white? On all the ereading devices I’ve been able to, I’ve read with white text on a black background so my eyes don’t start bleeding from the brightness of the screen.
April 30th, 2009 at 6:54 pm
I remember that old green glow
When I was using MSDOS on a color CRT, I used to set the text color to green, to match the green CRT I had been using. My first computer was a TRS80, which had a B&W screen. I spent many an hour in front of that.