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Saturating glass cellular windshield

See in the face of oncoming headlamps
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Disclaimer: You may have to drive with your head clamped in a vice.

This is a windshield made of glass that saturates at a defined level of light. It allows light up to a certain intensity to pass through, then becomes dark so that the amount of light passing through remains constant. If not glass, certain electronic (and opto-electronic) devices have this property. An example will be one cell of a photomultiplier channel plate.

Since, in order to provide protection against glare, the system will have to effectively trace a ray from the driver's eyes to the offending headlamp, the windshield is made in the form of cells effectively channeling the light along them and allowing light only in the direction of the driver's eyes, rather like the construction of insect eyes. And there lies the obvious limitation: If your eyes stray far from the focus of those channels, you can't see a thing.

The saturating glass is applied as a thin layer on the inside part of the channels. As you drive at night, the high intensity light from headlamps cause the glass to saturate and thus limit the amount of light reaching your eye. This prevents dazzle, making the scene as clear as it will be in the daytime.

The effect will have to be made switchable or of variable threshold in order to drive with it in the daytime.

neelandan, Jun 04 2002

Light Valves http://www.refr-spd...echno_howworks.html
An emerging technology. [reensure, Jun 04 2002]

Well, ain't that sweet http://sarina.koury.com/gatling_gun.htm
This 10 year old kid has been shooting a gatling gun since she was in 3rd Grade. She started shooting at the age of 8 while in 2nd grade and has an arsenal of weapons. She's also the youngest USA'n to earn a Black Belt in Karate at age 6. Bet she doesn't get "F's" on her report card, or teachers blinding her with headlights. [thumbwax, Jun 05 2002, last modified Oct 17 2004]

ImagineOptix Polarization Conversion System (PCS) https://www.imagine...-conversion-system/
The solution to //A polariser you put on your headlight immediately reduces its light output without benefit to yourself.// Claims to //polarize up to 90% of incident light.// [notexactly, May 19 2018]


       Another way to get the same result would be to have a filter placed over the headlights of cars and another filter placed over your windshield. The filter on the headlights would allow light to shine with only vertical direction of the light, creating polarized light. The filter on the windshield will block light only with the specific vertical direction.   

       The visual effect is quite simple: since almost every lightsource shines using every direction, the driver can see verything...except the light that comes directly out of the headlights.   

       Such filters already exist in polaroid sunglasses, and are in use in other area's. I know of one case where the BBC has an indoor camera pointed at the wheather presenter. At the background is a window showing the outside wheather. To accomodate for the occasional blinding light of sunny London wheather a filter was placed on the window and a filter was placed on the camera. By turning the filter on the camera they could control the amount of light coming from the outside.   

       For all of you with a physics background: I am not familiar with the English terminology, so I hope this solution sounds realistic.
spekkie, Jun 04 2002

       Whatever happened to good old fashioned Gatling Guns?
thumbwax, Jun 04 2002

       I had this idea a few decades ago, but in the form of sunglasses. That pretty much solves the "head clamped in vise" problem, plus it's more widely applicable.
jtgd, Jun 04 2002

       so if *your* headlights have vertically polarizing filters, and *your* windshield has horizontally polarizing filters, how are your headlights helping you? You can't see the light from them because it reflects off the road and other nearby objects with largely the same polarization (vertical) that it had at the source.
BigBrother, Jun 04 2002

       [BB]: you could overcome this by having a 45 degree polarisation on both the windscreen and the headlights. If you were facing the same direction as the lights, you'd see them. If you were heading in the opposite direction, the light would be blocked.   

       But I don't think that's the way neelandan was thinking of doing it.
yamahito, Jun 04 2002

       Wouldn't the reflected light lose its polarization?
phoenix, Jun 04 2002

       What [spekkie] describes was on this site for a while as "polarized windshields and head lights", and had actually been invented in history; I don't remember why it didn't catch on.
jutta, Jun 04 2002

       People with implanted lenses in their eyes experience this to a degree.
A. More light is admitted to the eye, so that diffusion (i.e. glare) is reduced and objects seem clearer.
B. The combination of defects of muscular coordination and minute difference in lens placement in bilaterally implanted eyes leads to some bizarre visual effects like one stripe of a double yellow road line seeming to vear off at a 90² angle.

       For another take on light valves, see the provided link.
reensure, Jun 04 2002

       spekkie, jutta: A polariser you put on your headlight immediately reduces its light output without benefit to yourself. Unless forced by legislation, I do not see that catching on.   

       tw: If you would ship me a sample, I could mount it on my car, try it out and then get back to you. About its effectiveness in reducing the after effects of stress induced by super-bright headlights shining into my eyes from opposing cars at night, that is.   

       jtgd: The way I envision it, it is going to be too thick for sunglasses, or need connection to a power supply, or both.   

       reensure: That spd thingie controlled by a photocell seems to fit the ticket.
neelandan, Jun 05 2002

       I got my hands on a Newton's Optics ebook, and he lost me on about 1/3 of the first page (sighs).   

       On the other hand I did also find "A Colour Atlas of Poultry Diseases", which I might try on a rainy day.
not_morrison_rm, May 19 2018

       //A Colour Atlas of Poultry Diseases//   

       I don't want to spoil it for you, but the plot twist at the end is outstanding.
Wrongfellow, May 19 2018


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