Quote:
Originally Posted by bobski
Who is "they"?
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Idk, i read the Wikipedia article on HUD and thats how they said it was done.
Now its not clear to me if they do reflect indvidual wavelengths like that in car windshields or not. I dont know if they need to do that because they're not covering the whole screen like a fighter jet just a small part of it above the dash.
Some of the aftermarket HUDS include a square of partially reflective tint to stick on the glass. That area of glass looks somewhat darker but the reflected image on inside of the glass is much much brighter so you dont need as much power and the ghost image on the outside is dimmer in comparison. You should probably try that. I've heard that the original GM car windshields had a darker spot where the HUD would be but the newer ones don't the whole window looks like the same tint level. Im not sure if the area above the hud and dash is more reflective and less absorptive tint or if its wavelength specific or if theres no difference there.
Lookup Dupont wedge. Apparently they can vary the thickness of the glass and plastic layer between the layers of windshield glass so it forms a wedge shape above the HUD that aligns the two reflections from the inside and outside surfaces of the glass so the driver sees only one image and no ghosting ! Wonder if a wedge could be stuck to the inside surface?
I found an interesting article where GM created a whole screen HUD that had layers of different color phosphors that illuminate when hit by lasers. Neat research.
Edit:searching this thread now i see you've mentioned tint. After reading the Wikipedia i searched for combiner here and didn't see it mentioned. this thread is 8 pages long but heres one that is 47.
http://www.mp3car.com/vbulletin/hard...rputer-47.html
edit2: That is how they do it on the new GM cars.
http://www2.dupont.com/Automotive/en...e20050606.html