Electrochromic Visor Aids Motorcyclists

opticsorg writes "A team from Uppsala University and the firm Chromogenics Sweden AB have developed a flexible electrochromic foil and integrated it into the visor of a motorcycle helmet. The result is a visor that the rider can electronically switch between dark and transparent states. Applying a voltage of about 1V to the initially transparent visor causes it to darken in a matter of seconds. When the voltage is turned off, the visor keeps its properties, while applying a reverse voltage makes it revert to its natural lightly tinted state."

Comments

MIT and LCDs

[Mr. Darl McBride]

Something similar was tried as a studen project at MIT. They used a flexible LCD panel, fixed over the faceplate of a motorcycle helmet. It had the desired effect, letting them dim the view during the day and lighten it at night, all with just three AA batteries, a rocker switch, and a simple 555 strobing timer circuit.

The project lead didn't manage to show up for the project class presentation however; he'd wiped out on the way to school.

Apparently on a colder morning, the LCD began to dim on its own as the cold wind affected the crystals, making them darken slowly and subtly. By the time he consciously realized he wasn't seeing well, he'd already skidded into the back of a flatbed truck!

I guess the simple lessons can be painful ones at MIT.

This isn't "transparent"

[wowbagger]

The maximum transmissivity is 50% - in other words, at its "light" setting, it STILL blocks half the light coming in.

At its "dark" setting, it transmits 20%.

So what you have is not "clear" and "krylon black", but rather "dark" and "darker". While this is useful, it still would be darker than clear.

And for all the people who will post about "I want this on my car" - no, you don't. Many municipalities have a legal limit of about 90% on car windows - pass less than this and the nice police officer can ticket you. Since 50% < 90%, if the cop wants to give you grief he can.

Re:This isn't "transparent"

[Shiifty]

50% still isn't good enough for night time riding. I use a tinted visor on my helmet and sometimes get caught out after dark without my clear visor. The tint isn't too dark, maybe 35% but its enough to make you feel uncomfortable on main streets, nevermind rural areas. 50% wouldn't be much better. Simple solution, just flip it up if you get caught out, thats what I do.

Re:This isn't "transparent"

[bill_mcgonigle]

And for all the people who will post about "I want this on my car" - no, you don't.

Aww, c'mon, I've been waiting 20 years to say, "KITT, darken windows".

Forget motorcycles... windows!

[Tom7]

Sweet. I've always wanted window panes that I can "turn off", and this is getting pretty close. Liquid crystals aren't so good because you need to keep the voltage applied in order to keep the crystals aligned.

I would buy one

[HotButteredHampster]

If this makes it to market in Canada, I will be first in line to get one. Vision is tremendously important when operating a motorcycle, and tinted visors are a bad compromise at best. Magazines suggest that you should have a second, clear visor and change it after dark, but there are different situations such as tunnels, forest roads, and even weather changes that can darken a sunny day but are easy to wave off as not bad enough to stop, dig out a clear visor and install it.

This would be much more convenient and by extension, safer.

Sunscreen for the Car

[sunbane]

We looked into this several years ago after doing a digitized lighting system for a wealthy family up in New Hampshire who had glass capable of this effect in their shower, overlooking a beautiful valley. If you wanted the privacy you could instantly have it. We thought, this is perfect for when your car is parked... block all of the suns rays and heat with a simple switch - no more need for those cardboard sunglasses. Unfortuneately the only supplier we could find wanted $5000 / sq. foot. But, if prices have come down, this would be pretty cool to have.

been out for years

[austad]

Welding visors have had this for years. Kind of interesting it's only being used now in helmets.

The welding visors ran about $200 to $300 last I checked. When the glass is as dark as it needs to be to protect you, it's impossible to see through it to see what you're doing. Traditional visors require the user to leave it open, get ready the strike a spark, and then put the visor down right before. It's a pain in the ass, and if you're welding all day long, you're bound to accidentally strike a spark before the visor is down, leaving nice little trails on your eyes for awhile. With this, the initial spark is detected by a light sensor, and it auto darkens the glass. Much more convenient, especially when you need both of your hands to hold something in place before you start welding it.

I've always wanted something like this for the side windows in my car, and a nice little slider to adjust how dark they get. Alas, no one seems to make film I can apply. :(

Ah, a Danger-Sensitive Visor!

[ConceptJunkie]

It immediately darkens when dangers is near because what you can't see can't hurt you.

Now if they shrink it down to sunglasses size, we can all be like Zaphod Beeblebrox!