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New Material For Fast-Change Sunglasses, Data Storage

kdawson posted more than 5 years ago | from the epileptics-need-not-apply dept.

Data Storage 133

sciencehabit writes "'Researchers have developed a material that almost instantaneously (30 ms) changes from clear to dark blue when exposed to ultraviolet light, and it just as quickly reverts to clear when the light is turned off. The new material, one of a class called photochromics, could be useful in optical data storage as well as in super-fancy sunglasses.'" A comment to the article notes some of the potential dangers of quick-change sunglasses.

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Slow Memory (5, Insightful)

im_thatoneguy (819432) | more than 5 years ago | (#27719691)

30ms is pretty slow by memory standards.

Could you imagine a CD burner which takes 30ms per bit?

It'll need to get a LOT faster to be used in any kind of processing or storage medium.

Re:Slow Memory (5, Insightful)

erayd (1131355) | more than 5 years ago | (#27719711)

30ms is pretty slow by memory standards.

Could you imagine a CD burner which takes 30ms per bit?

It'll need to get a LOT faster to be used in any kind of processing or storage medium.

Who says you have to write things serially? Admittedly write latency would suck, but you can still get a phenomenal throughput if you write a whole bunch of bits in parallel.

Re:Slow Memory (0)

Anonymous Coward | more than 5 years ago | (#27720705)

Who says you have to write things serially? Admittedly write latency would suck, but you can still get a phenomenal throughput if you write a whole bunch of bits in parallel.

Sorry. 30 ms is still horribly slow. Even if you write, say, a whopping 15000 bits in parallel (which, BTW, is completely and utterly unfeasible), you'll still only get a throughput of about 60 KiB/s - the speed of a floppy disk...

Re:Slow Memory (1)

erayd (1131355) | more than 5 years ago | (#27720767)

Why is it unfeasible to write that many bits at once? As far as I can see there's no practical reason that would prevent a write system with far more than that many simultaneous channels - and more channels equals more throughput.

Re:Slow Memory (1)

maeka (518272) | more than 5 years ago | (#27720985)

You can fit that many UV diodes in a single drive enclosure?

Re:Slow Memory (2, Insightful)

Qzukk (229616) | more than 5 years ago | (#27721047)

Probably not, but I bet you could put a few big ones behind an LCD mask.

Re:Slow Memory (1)

jhfry (829244) | more than 5 years ago | (#27722871)

What about scanning the UV laser. I can't imagine that the material needs 30ms of constant high intensity UV light to change.

It may take 30ms to react to the light, but not require 30ms exposure.

Re:Slow Memory (2, Insightful)

Fred_A (10934) | more than 5 years ago | (#27719747)

Especially if you need to keep the UV source on to keep the data stored...

Re:Slow Memory (2, Insightful)

EdZ (755139) | more than 5 years ago | (#27720385)

And you need to keep refreshing RAM too. With a refresh every 30ms, this could be used for medium-term storage in an optical computer.

Re:Slow Memory (1)

LordLimecat (1103839) | more than 5 years ago | (#27722547)

except that each bit would have to have its own diode, or at least UV source, and at that point you could just remove the material and just use diodes for the memory. After all, each bit would have to be exposed (or not exposed) to uv in order to retain its state, so something else has to have a memory of that too.

Re:Slow Memory (1)

EdZ (755139) | more than 5 years ago | (#27722863)

Or one source and a mask. Or one source and a scanning mirror.

Re:Slow Memory (1)

dziban303 (540095) | more than 5 years ago | (#27720813)

Could you imagine a CD burner which takes 30ms per bit?

No, no I couldn't. Could you help visualize it for me?

Re:Slow Memory (0)

Anonymous Coward | more than 5 years ago | (#27721067)

33 bits per second?

Re:Slow Memory (1)

ChangelingJane (1042436) | more than 5 years ago | (#27721935)

Sure. Pick your most favoritest CD evar, and hold a lighter under it so the flame just barely touches. Hold until the disc begins to warp. That should give you a clear impression.

Re:Slow Memory (1)

Roger W Moore (538166) | more than 5 years ago | (#27722899)

Could you imagine a CD burner which takes 30ms per bit?

Could you imagine a CD burner that takes 30ms per CD?

Something missing? (4, Insightful)

OpenSourced (323149) | more than 5 years ago | (#27719717)

Nowhere in the article they mention how the data is going to be 'stored'. If you need to be constantly bathing the material with UV light just to keep it dark, there is not much storage going on, IMO. Of course there might be missing data from the article, but they should explain a bit more.

Re:Something missing? (0)

Anonymous Coward | more than 5 years ago | (#27719743)

I'm thinking that you put your sunglasses under an array of UV LEDs, and the coordinates describing the state of each LED are stored in that "C" drive bit in My Computer. Simple.

Re:Something missing? (5, Funny)

Jah-Wren Ryel (80510) | more than 5 years ago | (#27719759)

Of course there might be missing data from the article, but they should explain a bit more.

That part was written in photochromic ink, you need to get a copy of the original publication and expose it to UV light in order to find out those details.

Re:Something missing? (1)

tsa (15680) | more than 5 years ago | (#27720659)

If you need to be constantly bathing the material with UV light just to keep it dark, there is not much storage going on, IMO.
 
That's why you have to make sunglasses out of the stuff.

Re:Something missing? (1)

Arancaytar (966377) | more than 5 years ago | (#27721713)

If you need to be constantly bathing the material with UV light just to keep it dark, there is not much storage going on,

I'm not calling the concept feasible, mind you, but do remember that our dynamic memory is currently based on removing and re-applying an electric charge to billions of capacitors hundreds of times per second. DRAM, according to Wikipedia, is guaranteed to hold its state for 64ms. If this one has 30ms, it's not that bad.

(Or wouldn't be if it could *write* as fast as DRAM does. Of course the write operation must be far faster than the loss rate.)

Sun-Glasses? (0)

Anonymous Coward | more than 5 years ago | (#27719725)

Who in their right mind would want blue sun-glasses? For use on planet earth at least...

Re:Sun-Glasses? (1)

Fizzl (209397) | more than 5 years ago | (#27720271)

Mikko Alatalo of course

I tried it. (0)

Anonymous Coward | more than 5 years ago | (#27719731)

But the googles, they did nothing !

One more step towards peril-proof sunglasses (1)

janwedekind (778872) | more than 5 years ago | (#27719783)

no text

So when I turn out the lights... (4, Funny)

macraig (621737) | more than 5 years ago | (#27719785)

... I'm simultaneously deleting my entire terabyte of porn!? Noooooo!

Re:So when I turn out the lights... (0)

Anonymous Coward | more than 5 years ago | (#27719933)

Keep the light on while fapping ;)

Re:So when I turn out the lights... (1)

bobdotorg (598873) | more than 5 years ago | (#27720971)

... I'm simultaneously deleting my entire terabyte of porn!? Noooooo!

Hey - keep the UV lamp on. Get off _and_ get tan. Just try not to burn the bits.

Re:So when I turn out the lights... (1)

ChangelingJane (1042436) | more than 5 years ago | (#27721955)

Weirdest farmer's tan ever.

The eye adapts slowly (4, Insightful)

oneirophrenos (1500619) | more than 5 years ago | (#27719793)

It's all good and well, but the eye doesn't adapt to changes in lighting as fast as this material does. What if the lens (and the eye) were subjected to a bright light from the angle of, say, 70 degrees? This wouldn't be blinding, because it would not hit the area of high acuity vision on the retina, but would nevertheless cause the lens to dim. So we would have a situation where the light hitting the retina would be significantly reduced, but the eye would still be adapted to conditions of relative brightness. We would effectively be blind (think of going to dark indoors on a bright sunny day).

Re:The eye adapts slowly (2, Insightful)

Al Al Cool J (234559) | more than 5 years ago | (#27720431)

Perhaps. But it seems to me that the experience of these things going dark would be very similar to the common everyday experience of simply putting on a pair of sunglasses, something I've done in just about every lighting condition, and usually while driving. The only time I can recall it ever being a problem is when I've done it at night (cue Corey Hart).

Re:The eye adapts slowly (1)

Thornae (53316) | more than 5 years ago | (#27720903)

... usually while driving.

That's the problem with this and every other UV adaptive lens treatment: Glass (like, for example, your windscreen) blocks UV.
So, they don't actually work when you're driving.

This is why I always get frames with clip on sunglasses with my glasses. Although, since I always end up losing the sunglasses part within a year, I'm considering just lashing out and getting prescription sunglasses.

Re:The eye adapts slowly (2, Interesting)

0123456 (636235) | more than 5 years ago | (#27721045)

"Glass (like, for example, your windscreen) blocks UV. So, they don't actually work when you're driving."

Except in my experience that's not really true.

I had this discussion with my optician last time I got a new pair of driving glasses, and they do darken while driving despite the fact that the windshield should block the UV (though, admittedly, not as dark as they used to go when I drove a convertible).

I can only guess that the windshield doesn't block the full range of frequencies that cause the glasses to darken.

Re:The eye adapts slowly (1)

danpritts (54685) | more than 5 years ago | (#27722443)

my experience differs - in my accord, i had basically no darkening. in my miata, with the top down, i had less than i would have liked - the windshield blocked plenty of light and i still needed my regular sunglasses.

Re:The eye adapts slowly (0)

Anonymous Coward | more than 5 years ago | (#27721135)

This is why I always get frames with clip on sunglasses with my glasses. Although, since I always end up losing the sunglasses part within a year, I'm considering just lashing out and getting prescription sunglasses.

You don't have to get the specialized clip-ons from your optometrist. There are some after-market ones which are pretty good (and cheap). I'm partial to the Polar Optics spring-loaded clip-ons. My local Walmart has them in their eye center. There's three dozen sizes and shapes, so you can match your glasses pretty well, and about $20 beats the $60 my optometrist wanted for the clip-ons, and certainly beats the $100+ for prescription sunglasses.

Re:The eye adapts slowly (3, Funny)

swillden (191260) | more than 5 years ago | (#27721493)

Although, since I always end up losing the sunglasses part within a year, I'm considering just lashing out and getting prescription sunglasses.

Been there, done that. I lost the prescription sunglasses. Three times. I decided that I just have to squint.

Re:The eye adapts slowly (2, Informative)

blincoln (592401) | more than 5 years ago | (#27721599)

That's the problem with this and every other UV adaptive lens treatment: Glass (like, for example, your windscreen) blocks UV.
So, they don't actually work when you're driving.

Glass doesn't fully block UV. I take UV photos using regular glass lenses with a UV-A bandpass filter in front. I lose something like 3-4 stops of light sensitivity compared to visible, but at least some of that is probably due to the camera sensor not being designed with UV in mind.

Apparently glass does block UV-B, UV-C, and shorter wavelengths. My camera isn't sensitive to wavelengths shorter than UV-A or I'd test it myself.

Safety goggles? (1)

Roger W Moore (538166) | more than 5 years ago | (#27722957)

Interesting...but it suggests another use. What about safety goggles? 30ms seems to be considerably less than human reaction time to visual stimulus (190s grabbed from Wikipedia - no idea whether this is accurate for blinking). So this might be good for laser safety goggles - assuming it absorbs the correct wavelengths.

Obligatory Douglas Adams reference... (5, Funny)

LordAlced (1279598) | more than 5 years ago | (#27719801)

But does it turn dark in the presence of danger?

Re:Obligatory Douglas Adams reference... (1)

ScrewMaster (602015) | more than 5 years ago | (#27721261)

But does it turn dark in the presence of danger?

Yes. The lenses will leap out of a moving vehicle just prior to impact, while the driver cries "It works, it works!". Eventually, he will wake up in the hospital believing that he's really Leon Trotsky.

radiochromics ? (1)

AeiwiMaster (20560) | more than 5 years ago | (#27719807)

Does anyone know if a material exist with similar reaction to radio waves and what such a material is called?

Materials called radiochromics normally react
to radioactive radiation not radio waves.

Re:radiochromics ? (1)

Chuck Chunder (21021) | more than 5 years ago | (#27720111)

Radio waves are just a type of electromagnetic wave right? So they would be called photochromics too.

Re:radiochromics ? (1)

dtl (670833) | more than 5 years ago | (#27722981)

There just isn't enough energy in a radio frequency photon to mess with the electrons in material to cause this kind of effect. Perhaps if you jack up the power (the number of radio frequency photons per second) hitting your material then you might get it to change. Put it in a microwave oven for instance. By then you're already talking about dangerous levels of radio frequency energy.

epileptics-need-not-apply. Why not? (4, Interesting)

MichaelSmith (789609) | more than 5 years ago | (#27719819)

I can imagine situations where the ability to quickly remove a visual stimulus would actually help a person with photosensitive epilepsy.

Re:epileptics-need-not-apply. Why not? (4, Funny)

maroberts (15852) | more than 5 years ago | (#27719971)

Not to mention waking up in the morning and turning round to face the hideously ugly person you picked up at the bar the previous night.....

Re:epileptics-need-not-apply. Why not? (5, Funny)

value_added (719364) | more than 5 years ago | (#27720051)

Not to mention waking up in the morning and turning round to face the hideously ugly person you picked up at the bar the previous night.....

Your sister isn't that ugly.

Re:epileptics-need-not-apply. Why not? (2, Funny)

Trouvist (958280) | more than 5 years ago | (#27720087)

Yes, she is.

Re:epileptics-need-not-apply. Why not? (0)

Anonymous Coward | more than 5 years ago | (#27720407)

your mom

Re:epileptics-need-not-apply. Why not? (0)

Anonymous Coward | more than 5 years ago | (#27720503)

No, but your mom is.

Re:epileptics-need-not-apply. Why not? (1)

fast turtle (1118037) | more than 5 years ago | (#27720993)

that's my brother

Re:epileptics-need-not-apply. Why not? (0)

Anonymous Coward | more than 5 years ago | (#27721237)

my mum told me that you looked pretty gruesome too

Re:epileptics-need-not-apply. Why not? (0)

Anonymous Coward | more than 5 years ago | (#27721665)

But your mom is.

Re:epileptics-need-not-apply. Why not? (2, Informative)

maroberts (15852) | more than 5 years ago | (#27721851)

I don't have a sister. Wait a minute, whose bed is this? There's someone behind me... Damn, my glasses have gone dark, can't see a thing.

Re:epileptics-need-not-apply. Why not? (1)

budgenator (254554) | more than 5 years ago | (#27721511)

You just have to learn to sleep with your beer-googles on.

Re:epileptics-need-not-apply. Why not? (1)

westcoast philly (991705) | more than 5 years ago | (#27721691)

Oh come on, give us a situation that most of us would never be in. Pick up someone at the bar? Maybe if this bar had a Linux User Group meeting... and this ugly person is your mom, upstairs...

Re:epileptics-need-not-apply. Why not? (1)

ChangelingJane (1042436) | more than 5 years ago | (#27721971)

Morning-after goggles?

Re:epileptics-need-not-apply. Why not? (0)

Anonymous Coward | more than 5 years ago | (#27720781)

But this removes a visual stimulus by producing another visual stimulus, sudden darkness. Now imagine one of these reacting to a strobe light.

flicker probably not an issue (2, Informative)

boog3r (62427) | more than 5 years ago | (#27719869)

(not sure why i posted this on their website. i blame the booze).

Did a bit of math and figured out that at 60mph you would need a complete obstruction every 2.5 feet to induce a state change (on-off), 5 feet for a full flicker (on-off-on).

This compound cycles on-off 33.333 (repeating, of course) times/sec. Halve that for a full on-off-on cycle. The human eye can do fine with a video frame rate of 30/sec, but can detect up to 72 frames/sec.

It is possible the flicker may induce optical illusions, but not likely considering the optimal cycle time produces the highest flicker rate. Any UV transition slower will produce less flickers/sec, while a faster transition will create an increasingly static tint (chemical can't transition quickly enough).

Now sitting under a 60Hz black light, that may be kind of trippy.

Re:flicker probably not an issue (1, Insightful)

Anonymous Coward | more than 5 years ago | (#27719903)

FTA- "And the compound is so stable that the reactions can be repeated thousands of times."

Without doing the math(s), driving along a tree-lined road ought to kill 'em in a few hundred metres.

Re:flicker probably not an issue (4, Interesting)

dunkelfalke (91624) | more than 5 years ago | (#27719945)

as you might or might not know, the windshield filters the uv rays. phototropic glasses cannot function in a car.

Re:flicker probably not an issue (1)

boog3r (62427) | more than 5 years ago | (#27720009)

did not know that.

also, i never said anything about a car :)

Re:flicker probably not an issue (0)

Anonymous Coward | more than 5 years ago | (#27720201)

Who mentioned a car?
boog3r can jog at those speeds.

Re:flicker probably not an issue (1)

gaggle (206502) | more than 5 years ago | (#27720219)

Convertible?

Re:flicker probably not an issue (1)

tzot (834456) | more than 5 years ago | (#27720249)

Nobody said anything about four wheels.

Re:flicker probably not an issue (3, Insightful)

DNS-and-BIND (461968) | more than 5 years ago | (#27720289)

Apparently, I have hallucinated the suntan or sunburn that I get on long car trips. Thanks for the info, though!

Re:flicker probably not an issue (0)

Anonymous Coward | more than 5 years ago | (#27720363)

only the front blocks uv not the side windows

Re:flicker probably not an issue (0)

Anonymous Coward | more than 5 years ago | (#27720457)

Apparently, I have hallucinated the suntan or sunburn that I get on long car trips. Thanks for the info, though!

UV rays cause tans.
Infra-red rays cause burns.

Glass filters out UV
Tanning booths contain only UV.

Re:flicker probably not an issue (1)

value_added (719364) | more than 5 years ago | (#27720487)

Apparently, I have hallucinated the suntan or sunburn that I get on long car trips. Thanks for the info, though!

Commonly known as a trucker's tan.

On your next trip, I'd suggest wearing a wife beater [wikipedia.org] , and maybe some shorts with black socks. I'll guarantee your new tan lines will confuse rednecks, truckers and your fellow nerds. Freaking out the wife and kids is a bonus.

Re:flicker probably not an issue (1)

ChangelingJane (1042436) | more than 5 years ago | (#27721981)

No no, go the extra mile and wear just a bra.

Re:flicker probably not an issue (1)

dunkelfalke (91624) | more than 5 years ago | (#27722399)

Well, glas doesn't filter UV completely, but almost. That is the reason for using special quartz glas for UV optics and applications.

Re:flicker probably not an issue (1)

Inda (580031) | more than 5 years ago | (#27720725)

My eyesight went downhill about five years ago. I stumped up the extra hundred quid for my photochromic (is that what you meant?) lens. I was so annoyed that no one told me they don't work in the car.

My solution was to drive with my head hanging out the window. You have to keep your mouth shut because of the bugs-of-teeth issue, so conversation with passengers is near on impossible.

Seriously, I couldn't live without them these days. If the time from dark to light was reduced it would be fantastic.

Re:flicker probably not an issue (1)

dunkelfalke (91624) | more than 5 years ago | (#27721401)

yes, photochromic is the english word for it, sorry, i used the german term for it by mistake.

Re:flicker probably not an issue (3, Informative)

Bigjeff5 (1143585) | more than 5 years ago | (#27722109)

It filters UV-B and UV-C pretty well, but not UV-A. Phototropic glasses are usually less effective in a car, but not completely useless.

Depending on the wavelength it changes at, these sunglasses could either work great or piss poor. Should be interesting.

Re:flicker probably not an issue (1)

Shadow of Eternity (795165) | more than 5 years ago | (#27722501)

I'm going to regret it but where the hell did you get the up to 72fps number and if that's true why can almost anyone see the difference between a 75hz refresh rate and an 85hz refresh rate on a CRT.

But is the reverse reaction temperature sensitive? (3, Interesting)

misterjjones (1331965) | more than 5 years ago | (#27719975)

The biggest problem with current photochromics in sunglasses is not the speed, but the fact that they darken beautifully in strong sunlight, but only when it's cold.

In hot conditions the temperature sensitive dark=>light process is favoured over the uv sensitive light=>dark process and they stay clear. I don't want glasses that change colour quickly, I want glasses that change stay dark on the beach.

The only use I have for my current "light sensitive" glasses is if I ever go to the Arctic in summer.

Re:But is the reverse reaction temperature sensiti (3, Informative)

tresstatus (260408) | more than 5 years ago | (#27720395)

I believe you are totally missing the point for the light sensitive glasses. they are never meant to be sunglasses. they are meant to protect your eyes from UV rays so that you don't damage your eyes. they also only barely darken anything you are looking at, with it being most noticeable on white things, like clouds or sheets of paper. what they really excel at is taking the edge off when you are looking at an object that is extremely bright........ EXCEPT FOR THE SUN. you aren't supposed to stare at the sun while you wear these.

I wear glasses that have the newest version of the transitions lenses. they turn much faster in heat than they do in cold... just the opposite of the older version. even still, when i wear them, i can't tell that they've changed to dark until I take them off and look at them.

my advice is that if you want your prescription glasses to work on the beach, you have 3 options: buy prescription sunglasses, buy a style of sunglasses that comes with a built-in clip-on (usually magnetic), or get contacts and wear regular sunglasses.

Re:But is the reverse reaction temperature sensiti (3, Informative)

An ominous Cow art (320322) | more than 5 years ago | (#27721819)

I've been wearing glasses with photogrey lenses since I was about 8, so 35 years or so. I've never noticed a problem with them failing to darken in hot weather.

Larry

If only it would turn completely dark (1)

santax (1541065) | more than 5 years ago | (#27720115)

when Britney Spears suddenly is in sight.

Peril-Sensitive Sunglasses (1, Funny)

Anonymous Coward | more than 5 years ago | (#27720257)

So with a little work, we can finally have the Peril-sensitive sunglasses of Zaphod's fame.
Sign me up for a set.

Re:Peril-Sensitive Sunglasses (3, Funny)

PixetaledPikachu (1007305) | more than 5 years ago | (#27720451)

perl-sensitive sunglasses? sweet!

Re:Peril-Sensitive Sunglasses (2, Funny)

Anonymous Coward | more than 5 years ago | (#27720627)

Those would be useful too, and actually a lot more feasible with current technology. Just add a camera, a microprocessor running OCR, and a perl parser -- and turn the glasses opaque the moment the parser finds legal perl code. This could save millions of young programmers from brain damage. The only problem is to create software that can distinguish between perl code and random OCR errors.

Re:Peril-Sensitive Sunglasses (4, Funny)

1u3hr (530656) | more than 5 years ago | (#27720829)

I'd prefer ones that filtered out COBOL or FORTRAN myself.

useless for sunglasses (1)

Ptur (866963) | more than 5 years ago | (#27720369)

dark blue is useless for sunglasses, you need (dark) brown....

Blue, non-polarized, non car = whatever (3, Insightful)

markdavis (642305) | more than 5 years ago | (#27720377)

Although it sounds interesting, I doubt most people are going to want to look at the world through blue-colored glasses. What would be far more useful would be glasses that the *user* can decide when they turn dark and by how much. 80% of the time I wear sunglasses is in the car, and Transitions and other UV activated glasses are useless for that purpose because they won't change dark.

I also find that polarized sunglasses are *far* more valuable than just plain darkening glasses. Yet, there is no way to have changing, polarized lenses (right now). So.... give me glasses that can change from 100% clear to full polarized (50% dark at least), on-demand, instantly, and I will then get very excited :)

Re:Blue, non-polarized, non car = whatever (2, Informative)

miggyb (1537903) | more than 5 years ago | (#27720641)

Isn't that exactly how LCDs work? When no charge is applied to a liquid crystal, it lets light through, but when there's an electrical charge, it becomes dark. All you'd really need is a pair of glasses with a battery, photodetector, and two monochromatic LCD cells the size of the actual lens. I don't think it'd be that much of a pain in the ass to have to recharge your glasses at night.

Re:Blue, non-polarized, non car = whatever (1)

The_Wilschon (782534) | more than 5 years ago | (#27720953)

I'm pretty sure that the light coming from a white pixel on an LCD is linearly polarized. LCDs have a polarizing filter, then a liquid crystal that can polarize the light at a voltage dependent angle, than a perpendicular polarizing filter. If your liquid crystal layer is oriented parallel to either the front or back layer, then no light gets through. If it is oriented at 45 degrees to both front and back, then you get maximum brightness.

Unfortunately, if your light source is unpolarized to start, then after passing through one filter, it is reduced to 1/2 its brightness. Passing through another polarizer at 45 degrees reduces the brightness by 1/2 again (Malus' law), and then the third polarizer reduces the brightness by 1/2 again. This is maximum brightness for a typical LCD display, 1/8 of the backlight brightness.

Now, you could put just one fixed polarizer, and one liquid crystal layer. Then you could have a range of brightnesses from 1/2 incident to 0. If you only put the liquid crystal layer, you would simply be polarizing in a different direction depending on voltage. So you would always get brightness 1/2.

Now, this is all just extending the principles of LCDs. I don't know that much about the other properties of liquid crystals. It might very well be that you can turn their polarizing properties on and off to some degree, which would do what GP wants.

Re:Blue, non-polarized, non car = whatever (1)

maxume (22995) | more than 5 years ago | (#27721033)

It probably wouldn't be that big a pain in the ass, but most people want sunglasses that they think look good, not sunglasses that can be switched between clear and dark on demand, so it better not cost a lot extra (lots of sunglasses charge for the logo, so those would be easy to compete with on price, but you would be doing so at the cost of quite a bit of margin).

Re:Blue, non-polarized, non car = whatever (1)

mark-t (151149) | more than 5 years ago | (#27721569)

You are correct, although consider that most people who would want sunglasses that could also go clear probably wear prescription glasses already and do not want to deal with the hassle of switching to prescription sunglasses whenever they go for a drive or using a clip-on filter.

Re:Blue, non-polarized, non car = whatever (2, Informative)

fahrbot-bot (874524) | more than 5 years ago | (#27721357)

Yet, there is no way to have changing, polarized lenses (right now).

Although this won't help inside a car (as the windshield blocks UV), Transitions lenses can be polarized. As an alternative, they also offer Drivewear [drivewearlens.com] lenses that are polarized and respond to both visible light (less darking) and UV light (more darking). These are also available from Oakley [oakley.com] .

What's new? (4, Interesting)

ChrisMaple (607946) | more than 5 years ago | (#27720579)

I've used a welder's face shield that changes to dark in the presence of UV from welding faster than I can perceive. It changes back to clear when welding stops. Am I missing something that makes this new?

Re:What's new? (4, Informative)

pereric (528017) | more than 5 years ago | (#27720643)

Maybe that it doesn't need external power or control. IIRC, the auto-dim welding helmets I know of need an external power source (small solar panel + battery I presume), and dims by applying a current to the glass. I was also going to ask if this could be used for a simpler welding mask, but 30 ms is perhaps too slow for protecting against the lots of UV arc welding produces.

Re:What's new? (1)

budgenator (254554) | more than 5 years ago | (#27721587)

Not positive but I assume the "solar cell" is to detect the light from the arc, might not be that difficult to substitude a much smaller photo-electric cell and a hearing aid batter for the much larger versions used in welding helmets. Welding helmets are personal proctective gear where failure can lead to significant injury so they are over-engineered for saftey.

Re:What's new? (1)

kheldan (1460303) | more than 5 years ago | (#27721883)

That's LCD technology. There are photovoltaic cells on the mask powering it.

Re:What's new? (1)

NewbieProgrammerMan (558327) | more than 5 years ago | (#27722845)

Yikes...it doesn't go dark until it detects the UV from the welding arc? That would mean there's a short period of time where your eyes are getting a nice blast of UV. Anybody know how short it is?

I think I'll just stick with the manual flip-down glass, thanks.

Re:What's new? (1)

NeMon'ess (160583) | more than 5 years ago | (#27722973)

Why so dismissive? What if the amount of UV is comparable to flying across the USA five times a year? Maybe it's even less. Dismissing it when you don't have enough information makes you look irrational and reactionary. Or maybe the flippant last line was just a weak joke.

Only ultraviolet? So they are almost useless (1)

mark-t (151149) | more than 5 years ago | (#27721505)

Sure it can protect your eyes against potentially harmful UV radiation, but when driving, the car windshield is already blocking a lot of that... of course, it doesn't stop bright light from getting in though, and when driving west in the evening, particularly just after a shower and the sun has come out, something that automatically goes darker in bright light alone, even if the UV isn't particularly high, would be just as, if not more useful.

Re:Only ultraviolet? So they are almost useless (2, Informative)

rockNme2349 (1414329) | more than 5 years ago | (#27721737)

They are activated by ultraviolet light...

Since they turn dark blue, I'll let you figure out what type of light they filter out.

Re:Only ultraviolet? So they are almost useless (1)

mark-t (151149) | more than 5 years ago | (#27723123)

Doesn't help matters while driving if they are only activate by UV, since most UV doesn't actually get through a windshield, so the glasses would stay clear.

Re:Only ultraviolet? So they are almost useless (1)

BitZtream (692029) | more than 5 years ago | (#27723167)

UV filtering glass filters some, not all of the UV. Take a nice long car trip with the sun shining on you through those UV filtered windows, you'll still get tanned or burned given enough time.

Thinking Too Small (1)

Snowy_Duck (963442) | more than 5 years ago | (#27721673)

I think we could use this for more then just sunglasses. What about using it in a high rise building. I'm sure some architect could work having blue windows into the design of the building. Or what about if your office had blue windows during the day to give a nice calming blue tinge to the work environment but at night turned clear to allow a clear view of the city? I could see airlines (Virgin Atlantic specifically) installing these since they already have blue interior lights. What about night time use - does the small amount of UV light given off by a star cause it to appear blue? I think there's more possibilities then just sunglasses or data storage.
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