Quote:
Originally Posted by EatingPie
Don't LCD screens require refresh every 1/60th of a second (or a variation on that theme)? Or is that simply the rate the backlight (if it has one) flashes at? I'd never heard of a non-backlit LCD before this thread, so I'm not sure which it is.
|
Nothing on an LCD flickers. The crystals that represent pixels (the front matrix) stay stable during a charge. They don't go on/off, they only change color (or power state) when it's specifically requested.
The backlight doesn't flicker either. It's basically a big lamp behind the matrix that stays on
all the time the display is powered, even if the pixels in front are displaying black. This is the reason black color still has some brightness on an LCD screen, since the front matrix can't block all the light coming through.
The refresh rate on any monitor is the frequency with which a completely new image is sent from a graphics buffer to the screen. The "refresh rate" on an LCD screen is rather meaningless, so you'll see most LCD's with only a 60 Hz refresh. When an LCD display is sent the instruction to change a specific pixel to a certain color, and that pixel is already displaying that color, it doesn't change it, it leaves it alone. Hell, it's doing it's job already. So no flicker.
On an LCD, the important characteristic is
response time. Roughly, it is the time it takes an LCD pixel to change color. Low response time on old or crappy LCD's is the cause of
ghosting, that is, the blurred image you see when an object moves fast on such a display. You can see an example
here.
The reason our eyes hurt watching any LCD display is because you're basically staring at a light bulb. That's got to hurt, no way around it. You're eyes are not built to take that kind of high luminance for prolonged periods of time. Maybe we'll evolve
.
But the point is, a very well built LCD (like the one used in XO laptops from OLPC) that uses very little power and has proper contrast
without a backlight, is a very viable display for an e-book reading device. And no, it wouldn't hurt your eyes. It would be as pleasant as an e-ink screen
if built with proper contrast. This is very doable for monochromes.
But backlit LCD's? For
reading? Sorry Nate, those are an abomination. Even if you need to read in the dark, an e-ink screen with a front light beats it hands down.