Hmmm, LCD display's are TFT as well these days. Back in the day you either had passive matrix, dual-scan passive matirx, or active matrix (Thin Film Transistor). Today LCD and LED are both TFT/Active Matrix displays, right? I thought there was an LED backlight(s) behind the LED panel in an "LED TV" or most LCD phones for that matter. Some are back lit, some from the side. Is that totally wrong? I was pretty sure that the panel's in LED tv's don't have per-pixel lighting. I thought we were dealing with the same screen on both type of display.
So are you saying the OLED displays use less power than LED displays? I know that was an early claim but it seems that's usually not the case just based on devices I'm familiar with. The only time they use less power is when the display is mostly black or displaying dark colors maybe. That's what it seems. Do you have any numbers to compare them? I'm guessing that PenTile OLED displays come down close to the power consumption, or maybe a little better, than current LCD displays. That would explain why it seems like so many OLED displays are pentile now.
Yes, a clarification is in order and it's due to my mistake. In my cutting and pasting of my edits I inadvertently pasted TFT LED in the LED Display section. Truth is TFT LED, back in the day was used to identify an "Active Matrix" LCD display with Thin Film Transistors in place at each pixel junction to control that pixel. "Passive Matrix" was a method where the pixel didn't use a transistor to control the state of that pixel and instead the pixel could maintain its state on its own, and a matrix of wires was used to communicate with each junction, and the controlling happening at the motherboard level "LCD Controller".
The problem was that Passive Matrix" was slower to refresh and so the images were "ghosty" as they moved quickly across the screen, and video frame-rates couldn't be high or there would be lost frames. Since the controller needed to send signals down the entire matrix at one time, row by row, the entire matrix took relatively long to make a change, and by the time the bottom rows were done making the change, the top rows were falling behind the frame-rate. So then "Dual-Scan Passive Matrix" was devised, which divided up the rows of pixels into two sets, where every even row was controlled by one controller, and the odd rows by another. This allowed for much faster refresh rates and also for smoother transitions of image changes, leading to less "Ghosting".
"Active Matrix" was devised to change the state of the pixel (the angle of the crystals), between open and shut rapidly to reduce ghosting to almost negligible.
Then came LED which removed the slower LCD technology, removed the need for back-lighting, and allowed for much brighter displays, higher contrast ratios, wider viewing angles, less power consumption, and far faster refresh rates.
And yes, your description of LED Displays also being "Active Matrix" is correct. LED Displays are Active Matrix by nature, since each LED is backed by its own controlling transistor.
OLEDs are more efficient for two reasons...one, they use less power for the same number of lumens, and two, they use less power while at low light output levels. Non-Organic LED use nearly as much power at dramatically muted brightness as they do at full brightness. Since even while showing "black" LEDs AND OLEDs are actually "on" and activated (to keep the time to go from muted to bright minimized), they both use power, but OLEDs use far less power at the muted levels, so overall two displays, OLED and LED, displaying the same image, should show very different power consumption...and the OLED would be the winner for power efficiency at the same light levels.
And your observations are correct...the comparison is at the same light level outputs. Since OLEDs are able to produce more lumens, they can be "turned down" to reduce power consumption. But we as owners wanted MORE light, so we could see them in bright light, for instance...so they really are not "turned down" as they could be and would need to be to compare to LED displays in general. As a result, a present day OLED Display may consume comparable power with an image displayed, it will be markedly brighter at the same power level. On the other hand, at a rest state, or when there is a lot of dark screen areas, the OLED would consume considerably less power than a comparable LED Display.
For Pentile Displays, it wasn't so much a reduction in power as the primary purpose, as it was a reduction in the number of subpixels needed to produce a comparable resolution...which eventually results in less power consumption. Here's some great info on that technology from Wikipedia:
[h=2]History[/h]
Prototypic five subpixel repeat cell geometry of PenTile Matrix (zoomed at 12:1).
[h=2][
edit]PenTile
RGBG[/h]
Magnified image of the
AMOLED screen on the Google
Nexus One smartphone using the
RGBG system of the PenTile Matrix Family.
but with the announcement that the Q is gonna have a unlovkable boot loader let's pray and hope Moto comes through with our HD. No negative comments lol, I don't want anyone to ruin my hopes haha