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Chameleon Liquid Could Replace LCDs
InvisblePinkUnicorn writes "NewScientist reports on a color-changing liquid that could cheaply replace the color components of standard LCDs. According to researchers at UC Riverside, the liquid 'contains tiny iron oxide particles coated with plastic. It is cheap and easy to make, and could also be used in flexible, rewritable, electronic paper.' From the article: 'The opposing forces of electrostatic repulsion [in the plastic] and magnetic attraction [in the iron oxide] result in the particles arranging themselves into an ordered structure, known as a colloidal "photonic crystal". The colloidal crystal reflects light because the spacing between neighboring particles in the structure is equivalent to the wavelength of light. Also, tuning the spacing slightly alters the exact wavelength, or colour, of light that is reflected. This can easily be done by varying the strength of the magnetic field applied to the crystal.'"
Um, it's only fairly recently-ish we've had sub-6ms LCDs... it's funny you mention 8 ms because 8 ms is widely considered the "acceptable" gaming threshold, at least in my research when I was looking at buying an LCD a year ago or so. (Note: I held off until a couple months back, and my current display is 2 ms latency.) Not to mention, the panels on older laptop computers had significantly higher latency, and they were quite usable for basic office tasks.
the tags are right. The brown color is not in the hue (compare with rainbow), so controlling the wavelength is not enough. You'd need to controll brightness at least, and then brown would be kind-of dark-orange.
Also, if you rely on reflecting light (aka. mirror), you rely on fact that the light source HAS this color wavelength in its spectrum. This is not always the case if you don't use sunlight.
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#\ @ ? Colonize Mars
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I wonder if you realize that CRTs have a fade-out effect. Try swapping a pixel from full on to full off [any of the colours] and see what the observed waveform looks like. Hint: It's not square.
As opposed to an LCD which truly is at a given level, there is no fade out.
Sure your CRT may refresh at 200Hz but the phosphor coating doesn't.
Tom
Someday, I'll have a real sig.
Dude - I was making a joke play of the Weird Al line in All About The Pentiums -- about the newbie that had 'white-out all over your screen'. Besides, to be fair it doesn't say that paper would be made out of this liquid, just that it would provde the color/images. More likely is that this liquid would be the coating on the paper.
21st-Century-Citizen
Any electrical current will generate a magnetic field. I don't know why you think you need coils. Coils are used because the field overlaps on itself and there is an additive effect. But the article does not say how strong the field has to be, so there's no reason to believe that it will be necessary to use coils. It all depends on how strong the magnetic field needs to be.
"It's also hard to contain a magnetic field in a small space"
There is no need to "contain" the magnetic field, since each pixel would be dominated the nearest magnet (magnetic fields dissipate rapidly with distance).
200 micrometer is REAL BIG in lithography land. No problems there that I can see.
-- Cheers!
On the other hand, both hard drives and electromagnetic tape use tiny magnetic fields. So making this work is just a matter of coating the back with the same material we use for hard drives and setting the bits with a moving head (instead of a moving platter).
While that may not be practical (moving head, what am I thinking?), I did RTFA. The effect is caused by the opposing static and magnetic forces. So, if we can electrostatically increase the static charge on the particles, like we do in an LCD screen, then we can achieve the desired result.
And on the third hand, I sure hope this reflection is more like ink, and less like the reflective screen on a Gameboy Color.
For geek dads: Contraction Timer
You're right that the change isn't instantaneous on a CRT, but the maximum refresh rate of a CRT is very much related to the decay rate of the phosphors, at least after you adjust for the marketing lies. That's why fixed-frequency 60 Hz monitors (or TVs) don't have huge flicker problems, but a multi-sync monitor with a 180 Hz maximum refresh will put you into seizures if run with a 60 Hz refresh.
"the resolution and control still isn't very good"
Looks like a glass vial to me. With a single magnet in the middle. So, yeah, resolution seems to be 1:1 and they are showing off all the colors in the vial, not trying to make it a single color. And I *do* see most colors you would need, so that's a plus.
As for liquid paper: it can be made flexible, I suppose it uses little energy and it uses reflexion as well. Couple this with high dpi and this would qualify it for digital paper in my view. Actually, for me, it would even be viable for electronic paper even without the flexible bit. I have no issue bringing a light A4/letter slab with me if it can bring up all my paperwork on request.
>>Not really. It results in disappearance of the mouse cursor, and interferes with scrolling.
I guess it depend too on what you mean by "slow" response time. The OP in not so many words said it had to be fast enough to play video games without ghosting. Most applications are not that demanding.
If it was too slow you could not use a mouse or scroll, but their could be workarounds (page up and down instead of scroll, moveable focus rather than a moveable cursor).
Try this. Take your digital camera, put it into the highest ISO setting, open the aperture all the way, and take a really short exposure of a CRT screen. What you'll see is a block of scanlines (about 20 or so for a 1/1000s exposure) that is bright, and the rest of the screen, which is very dim by comparison. The transitions between the bright and the dark regions will be very sharp, which will show you that the phosphor decay is quite rapid, and you only see multiple illuminated lines because, even at 1/1000s, the exposure time is still too long to see a point.
Phosphors have an exponential decay, which means that they fall off to a fraction of their peak intensity fairly rapidly, but it takes forever for them to dim completely. That is why you see radiation in a dark room, but it is at a level that is MUCH smaller than the level you get even showing a black screen with an active electron gun.