Glasses

I'd like to build a prototype of an idea I had. I'd like a pair of glasses that can respond to ambient light levels and react accordingly. When the wearer goes into a bright environment, the lenses dim, while some bright LEDs could provide lighting if the wearer goes into a dark environment.

Here's what I'm thinking: take some frames and add a battery, a microcontroller running Arduino, a light sensor, some LEDs, and electric transition lenses.

-Battery and microcontroller have the obvious functions...
-The light sensor(s) are to check how much light there is: if there's an excess, darken the lenses, if there's too little, power the LEDs.
-The LEDs are basically to add a headlamp functionality
-The electric transition lenses... I know the technology exists, but I have no idea where to get lenses that do what I would like. The basic principle is that there is a lens made of two parts with a layer of a special chemical in between, and when the chemical receives electricity, it darkens. Does anyone know where I can get (or make?) lenses like that?

Thanks for your response! 8)

Maybe you can get a sample?
http://www.glass-apps.com/products/smart-glass-windows

The welding industry has something that seems similar.

Nelsyv:
-Battery and microcontroller have the obvious functions...

Function of battery is obvious, but not so the microcontroller. What's it do? Update Facebook when you go into another room? :astonished:

The dimming could be done using the 'welding mask' approach that Zoomcat mentions. In the non-welding environment I expect this could consist of an LCD panel. To power it, I would have thought solar power would be ideal (just like the welding mask, again).

I don't know how easy it is to buy a continuous LCD element - I can't imagine there is much demand for it. A welding helmet is actually the only application I can think of so you might need to think of ways to drive one of those and whether it's feasible to cut them down to size. Ben Krasnow has shown that it is possible to make your own, but also that you need a lot of specialised equipment and knowledge to do it. I guess the ideal would be a curved LCD to match the shape of the lens, which seems even less feasible.

CrossRoads:
Maybe you can get a sample?
http://www.glass-apps.com/products/smart-glass-windows

I’ll look into these, it said something about a film you can retrofit windows with, so maybe I can put it on small clear lenses. Although, it runs on 110V, so it would be hard to power it, and after a quick look at the product specs page it looks like it needs to be powered to be clear, it would be far better to be the other way (power to darken), or running out of battery at the wrong time could be bad.

zoomkat:
The welding industry has something that seems similar.

http://www.harborfreight.com/adjustable-shade-auto-darkening-welding-helmet-46092.html

http://manuals.harborfreight.com/manuals/46000-46999/46092.pdf

I’ve seen one of these before.
I think the way they work (just guessing by looking at them) is that the view panel is an LCD with no backing, and when the solar panel at the top is powered, the liquid crystals are powered to turn, blocking the slits of the polarization.

Do you think there would be a way to do this with a regular LCD by removing backing or some other modification? Obviously if this were a real product (like if I was mass-producing/selling them) I’d get custom lenses produced, but I’d really just like to prototype the concept here.

Paul__B:

Nelsyv:
-Battery and microcontroller have the obvious functions…

Function of battery is obvious, but not so the microcontroller. What’s it do? Update Facebook when you go into another room? :astonished:

Well, it controls all the other parts of course! Sorry, thought that would be clear. Since the algorithm might be a bit more complicated than a linear relationship between ambient light and lens darkening, I figured a microcontroller would be the simplest way to do it all.

PeterH:
The dimming could be done using the ‘welding mask’ approach that Zoomcat mentions. In the non-welding environment I expect this could consist of an LCD panel. To power it, I would have thought solar power would be ideal (just like the welding mask, again).

I don’t know how easy it is to buy a continuous LCD element - I can’t imagine there is much demand for it. A welding helmet is actually the only application I can think of so you might need to think of ways to drive one of those and whether it’s feasible to cut them down to size. Ben Krasnow has shown that it is possible to make your own, but also that you need a lot of specialised equipment and knowledge to do it. I guess the ideal would be a curved LCD to match the shape of the lens, which seems even less feasible.

I guess great minds think alike, because I was thinking of using an LCD panel too if I couldn’t figure out the electrochemical dimming. However, I haven’t heard the term “continuous LCD element” before, so how are they different from a regular LCD?

I don’t know who Ben Krasnow is, but I know that I don’t know how to do this myself.
I agree, ideally I would have custom lenses made just for this, but that costs a lot more money than I think it’s worth for one prototype.

Nelsyv:

Paul__B:
Function of battery is obvious, but not so the microcontroller. What's it do? Update Facebook when you go into another room? :astonished:

Well, it controls all the other parts of course! :sweat_smile: Sorry, thought that would be clear ...

Anything but obvious. You have a light sensor, you have some sort of actuator which you want to respond to the light sensor, so you connect the one to the other. What do you expect the Arduino to do?

For example, if you wanted to control a servo position according to a light level, you do not use an Arduino, you use a (CMOS) NE555. Same for any other actuator that requires PWM.

Just wondering ...

{By definition, protective darkening systems would default to dark, so presumably that is where research is directed. Mind you, the simpler welding goggles would appear to darken on excitation where this is provided by a photocell which is necessarily more reliable than a battery - and if it isn't reliable, the game is clearly lost anyway. Hmmm.}

I recently posted an idea on the Ideas page of the Arduino Playground at Arduino Playground - HomePage. Here's what I posted.

Here's something I've wanted to do for a long time. It's funny, or more like totally zany. Imagine, if you will, a pair of sunglasses. Preferably big, round sunglasses. We make them with polarized lenses, being careful to align the polarization at the same angle in both (fixed) lenses. Then we have another set of polarized lenses in front of the two fixed lenses. Now imagine we have a motor, and a drive belt or gears, or a chain that will turn the two front lenses. We mount a photocell somewhere on the earpieces such that it looks forward though the lenses. When the light through the lenses changes, the photocell detects it, and the Arduino (preferably a very small one), drives the motor, letting in more light or less light. As the wearer turns his head, the lenses react quickly (and perhaps a little audibly), to the astonishment on onlookers. I visualize them as somewhat "steampunkish" in appearance.

La3ry, I don't think the onlookers would notice anything the variable polarizer setup, unless perhaps you made the gears visible. And to wear it, you could only use it on really bright days outside (or of course wielding), since each polarizer reduces the light level 50 - 75%.

However, it occurs to me that if you want to be flashy and do something for seeing, that you might think of the old video cameras that had 3 lenses, such as http://www.google.com/imgres?imgurl=http://photos.streamphoto.ru/c/9/0/d8f66007a43957a77b6130a330e6c09c.jpg&imgrefurl=http://www.ebay.com/itm/Rare-vintage-Soviet-Ekran-4-8-mm-2x8-mm-film-movie-camera-with-3-lenses-/150984251542&h=1284&w=963&sz=131&tbnid=XXw5PJoA4G4fLM:&tbnh=93&tbnw=70&zoom=1&usg=__P28tbr07qacYxol3dFdD2PDT85w=&docid=0zmcvdGHiDIXMM&sa=X&ei=G4ikUrfsOZKgkQftzYHoCA&ved=0CHYQ9QEwBQ. One lens might be a normal lens, one a polarizer, and maybe one colored.

In terms of steampunk goggle hacks, I've been playing around with neopixel rings, which where made to be just the right size to fit in a lot of goggles (though note, it is more for wearing on your hat and not looking through, since the LEDs can get really bright): NeoPixel Ring - 16 x 5050 RGB LED with Integrated Drivers : ID 1463 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits

I have been thinking of putting a gear on the outside with a motor that randomly turns on/off that just spins.

Another thing I've thought of is to put a clock mechanism inside one (or preferably a counter-clock that runs backwards), but unfortunately the standard clock mechanisms are a little too big for goggles.

And I keep thinking about getting these, and doing something about the blue plastic: Wiper Eyeglasses

MichaelMeissner:
La3ry, I don't think the onlookers would notice anything the variable polarizer setup, unless perhaps you made the gears visible. And to wear it, you could only use it on really bright days outside (or of course wielding), since each polarizer reduces the light level 50 - 75%.

Hmm... I was sure you could get get polarizing film that transmits a lot more light than that. Oh well. The visible gears/belt/chain and perhaps even the motor, is what I had in mind for the Steampunk look.

And I keep thinking about getting these, and doing something about the blue plastic: Wiper Eyeglasses

Ha!! Those are GREAT! At my age, I probbaly shouldn't even be thinking about stuff like this. I guess I just didn't grow up.

lar3ry:

MichaelMeissner:
La3ry, I don't think the onlookers would notice anything the variable polariser setup, unless perhaps you made the gears visible. And to wear it, you could only use it on really bright days outside (or of course wielding), since each polariser reduces the light level 50 - 75%.

Hmm... I was sure you could get get polarising film that transmits a lot more light than that. Oh well. The visible gears/belt/chain and perhaps even the motor, is what I had in mind for the Steampunk look.

I had a mind to chime in earlier.

As a matter of definition, a polariser reduces the light by 50% since it is removing the (component of the) light polarised in one particular direction, which is half of the light.

However, halving the light intensity is not a tremendous visible reduction. Polarised sunglasses use a polariser and a quite strong neutral density filter so that the reduction in the favoured polarisation is substantial and in the blocked direction, extreme. That is, polarised sunglasses are not just polarisers.

You "test" polarised sunglasses by holding two pairs together and relatively rotating them. In the favoured direction, the two together will be much darker than one alone. Pure polarisers however will be negligibly darker when two are stacked in parallel polarisation because each will only be rejecting light in the same polarisation.

Note that most LCDs use polarisers - whilst this reduces the overall visibility, it does not reduce it that much.

The trouble I find with LCDs is depending on the angle, you won't be able to read the LCD at all with polarized sunglasses on (due to the LCD being polarized, so it acts like 2 polarizers). So on my main cameras (made by Olympus), I can generally use the LCD to frame the shot when shooting in landscape orientation, but I can't see the image at all when shooting in portrait orientation. If I use the external viewer (VF-2) on my Pens, it is just the opposite, in that I can frame the shot in portrait mode (though there is a big blob in the center of the shot), but I can't see at all in landscape mode. Which is unfortunate, since I was wanting to use the VF-2 like the optical viewfinder on my DSLR and put it up to my eye to block out the sun, but I pretty much need to wear the sunglasses at all times when I'm out side.

OK, so polarised sunglasses are specifically oriented to vertical polarisation, as that is the element of specular radiation and glare that is minimised.

Some "bright spark" in the engineering department of Garmin was responsible for the gross blunder of fitting one series of Navigators - of which I own one - with a horizontal polariser which renders it unusable in the car (or anywhere else really) whilst wearing sunglasses .

Yeah, I've seen similar things. It's not like wearing polarized sunglasses is a novel thing that only 1% of the population does, and you can ignore it.