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New Display Technology to Compete with LCDs?
NetRanger writes "C|Net's News.com has a really interesting article to a new display technology that is based on interference of light patterns. The company, Iridigm, has a very compelling case for why their display method is far superior to LCD, including far brighter displays, far less power consumption... but the cool this is that the display actually works like RAM (it retains its state until voltage is applied to reset it) -- so what do you see when the driver crashes?"
Only like SRAM, not DRAM.
SRAM is pretty much static until changes are made, DRAM you'll hear described like a leaky capacitor. When you give it a charge it will slowly loose it, so you need to refresh it... many many times per second.
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This technology is great for displaying text (and pictures of butterflies) but it is very bad for games.
Look at the description of how it works. The colour is determined by the distance between glass layer and the metal plate. Big gap = red. Small gap = blue.
This is fine for static images, but it means that it takes 5 times as long for a red pixel to change state as it does a blue one.
When you have a quickly moving image, the result in severe ghosting for red objects. White objects will leave a rainbow trail - red at the far end, blue near the object. Blue objects are relatively unaffected.
If you do use this for playing Quake 3, just make sure you're on the blue team.
IANAEES....
Both SRAM and DRAM require constant power to reliably store data.
SRAM differs from DRAM because the cells that hold bits are always charged [howstuffworks has a diagram, basically its 5 logical gates in feedback]. As a result SRAM takes more power but has no refresh delays [and is bigger]
DRAM uses capacitors to store the data and requires refreshing. This makes DRAM smaller, less power instense but much slower.
For example, cache inside processors is a version of SRAM. If SRAM were as cheap as DRAM we'd be seeing 2MB caches common place nowadays...
Anyways... Peace out.
Someday, I'll have a real sig.
This is more for those that don't know :)
60Hz refresh is ok-ish in places like Australia, New Zealand and anywhere else using 50Hz mains rather than North America's 60Hz. The flicker you see on a monitor is caused by the monitor and the room's lighting interfering with each other and causing beat frequencies: very much like two musical instruments that aren't quite in tune.
Bill - aka taniwha
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Leave others their otherness. -- Aratak
I heard on NPR the other day an even neater sounding alternative that is about five years off.
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It uses the fact that certain plastics when charged with electricity will emit light and certain colors. The screen would be flat and completely flexible.
Literally you would have a screen (a TV for example) that could be rolled up and put into your backpack.
Right now they are looking into small scale electronics applications of the technology in terms of putting in screens for car radios and such but they have the big plan of a flexible plastic tv or computer monitor.
Of course if you pay attention is the fact that it needs no backlighting and can be extremely thin. Very neat stuff.
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ACK
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They have a Palm display side-by-side with display with their technology. (it's b&w) you canhardly see any individual pixels on their screen. Text is rather crisp, almost printed.
Why aren't you encrypting your e-mail?
SRAMs can be designed for raw speed (CPU caches) or low power (CMOS memory in old PCs before flash). High speed SRAMs can suck down a lot of power due to all of the gates and frequent logic transitions.
OTOH, The low power SRAMs intended for nonvolatile storage use all CMOS FET transistors in their logic gates. These gates draw essentially zero current unless they are actually switching.
Thus, while low power SRAMs require a voltage (typically supplied by a battery) to retain their state, they draw no current when idle. Therefore, in a technical sense, they don't actually require "power" (voltage*current) to keep their state, just a static potential.
A hydraulic analogy would be rigging two toilet flush flap valves in series, then ensuring that they never open simultaneously. This setup could store one bit (1 - open/closed, 0 - closed/open) with just static water pressure and zero flow. (A little water would flow when the valves are actually flipped.)
(btw, IAAEE)
[i]The flicker you see on a monitor is caused by the monitor and the room's lighting interfering with each other and causing beat frequencies: very much like two musical instruments that aren't quite in tune.[/i]
I usually have all the lights off when I work on a computer, and I can still see flicker whenever the refresh rate is under 85Hz. I've had cases where some unrelated change in my video driver settings caused (for whatever reason) the refresh rate to drop to 60Hz, and I had to go fix it because the flicker was bothering me so much. It has nothing to do with room lighting.
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Where an iMoD display wins isn't in framerate -- that's going to be driven by your graphics card, anyway -- but in the fact that it has no refresh per se, the way a CRT does. The problem with conventional CRTs is that the screen image is drawn in an essentially serial manner -- each pixel is displayed in scan line order, scan line by scan line. If you update the screen image data faster than the monitor can draw the whole image on the screen, you can wind up drawing the top part of the screen with data from frame X, the middle from frame X+1, and the bottom from frame X+2. If the screen image data is changing rapidly, the visible objects on the screen may not line up correctly across the whole frame; this is artifacting.
The iMoD display, because the pixels are addressable randomly, the same way that LCD displays are, can 'back up' to the top of the display for each frame. The pixel update time is short enough that, unlike LCD displays, you're not going to get 'trails' (and the pixels can be updated many more times per second than either an LCD or conventional monitor), and the addressing electronics can be designed to allow more than one pixel to be updated at a time, making a whole-screen update even faster, so that it's not impossible that it might be able to obtain an order-of-magnitude increase in screen redraw rate over a 60Hz (read: rock-bottom) CRT.
But the real advantage comes more from the fact that, without the screen redraw being tied to a fixed sweep rate, the actual display refresh rate can be exactly the same as the frame rate produced by your video card. With a CRT running at a refresh rate of 72Hz, no matter how many frames your video card can draw per second, you're only going to see 72 frames per second; having a video card that can draw 90 frames a second on the simple scenes only means that you can lose 18 fps due to scene complexity before you see any frame rate loss. With an iMoD display, if your video card can render 90 frames per second, you would be able to see all of them. On the other hand, since the display updates would be matched to the video card's frame rate, degradation of your frame rate due to scene complexity would be immediately visible (subject to the response of the human eye).
Most metals exist in more than one form of crystal matrix. These different types of crystals exist in almost every chunk of metal you find. You will usually end up with a small area of one form of crystal (with all atoms lined up in the same direction) which is surrounded by another form of crystal. These small areas are called grains. The smaller these grains are, the more easily the metal bends, due to the fact that the atoms on the edge of a grain do not bond well to the atoms outside the grain.
When you bend metal you tend to form more grains in it, due to the movement breaking up existing grains and splitting them into smaller pieces. The increase in grains causes the metal to weaken, even if it is a small amount every time. If the metal is allowed to "relax" for a period of time, there is the chance that two extremely close and aligned grains will convert the atoms between them into their crystaline form. This reduces the amount of grains and re-stiffens the material. This re-conversion is very slow under normal temperatures and pressures and thus is a minor effect.
You can increase the grain size and lower the number of grains by heating the metal at a certain temperature for a period of time. If you then quickly cool the metal (quench it in water, for example) you will end up with a harder material (but more brittle). This is how blades are made that hold an edge and stay sharp, the harder the blade is the better it will hold an edge. However, if you make the blade too hard then it will not bend at all and it will be brittle.
Sapere aude!
I used to work as an aquatic biologist, diving and photographing fishes from all over the globe. My photography skills are legendarily poor, but even the experts I worked with were continually frustrated with the inability of film to capture the brilliant metallic and irridescent colors we saw in person.
Alas, while it may be possible for this display technology to duplicate some of the bright colors, interference colors are usually dependant upon binocular viewing for most of their spectacular effects, and the monitor will definately be mono.
Finally, while I wish it were't so, this technology seems to be display only. I see no ready bridge to adopt this technology to CCD's or film (our two existing image capture options) or to use it directly as a capture device. More's the pity.
You'll have to excuse me, I was shooting from the hip and didn't realize that I had made a mistake in my original discussion.
I originally said, "When you bend metal you tend to form more grains in it, due to the movement breaking up existing grains and splitting them into smaller pieces. The increase in grains causes the metal to weaken, even if it is a small amount every time."
This is not exactly true, it had been a while since I studied metallurgy and I didn't have any reference texts to consult. To clarify, the reason the metal weakens is not that the number of grains is increasing and making the material more ductile (easily bendable), but that the dislocations (areas of stress in the metal matrix) and impurities are getting moved to the edge of the grains and are collecting together. This means that less of the metal has flaws distorting its structure and is therefore harder. Since it is harder it is now less flexible and more brittle. This causes micro cracks to form during the bending. Eventually these cracks lengthen and the metal fails.
Work hardening occurs when the metal is plasticly deformed. These deformations cause impurities and other strains to gather together and less distort the structure of the metal. Since more of the metal is ordered, it is harder than it was originally.
One thing you should know is that metallurgy is very complex. There are many factors which enter into the equation, such as grain size, alloys, impurities, many different phases (crystal structures) of the metal, etc. Often simply how the metal is composed, heated, cooled, worked can vastly change its properties.
Here are some sites to study more about metallurgy:
PLANT MATERIAL PROBLEMS - a site on metal failure
Metallurgical Terms Made Simple - a site on the basics of steel metallurgy
The Metallurgy Of Carbon Steel - a more in-depth analysis of steel metallurgy
Sapere aude!