LCD sun glare with mounting angle?

**Arathranar** · 10-07-2004, 12:00 AM

Has anyone experimented with what effect the mounting angle has on low sunlight readable your lcd is? I've been playing with the angle of a 10.4" lcd and it seems that there is a sweet spot where there is very little light being reflected at me because the lcd is pointing at the car roof if you viewed it as a mirror.

**mi800** · 10-07-2004, 01:03 AM

Lilliput during day is unreadble. My car has 50% tint with beige interior. I did little experiment to reduce glare and found out;

1. The color of interior had significant impact on glare.
2. tint- it helps a little, but don't expect a miracle.
3. angle - I was told when the screen is facing up, it will produce more glare because it sees more lights coming from outside. Well, my experiemnt contradicts this theory. When LCD is perpendicular to eye(about 10-20degrees facing up), glare was at minimum.
4. Some say removing touch panel will reduce glare, but I don't want to lose the touch screen.

My screen is currently flushed to dash due to easier installation, but I'll eventually do tilt mount Lilliput someday.

**ppgt94** · 10-07-2004, 01:15 AM

Touch screens = lots of glare. I don't have to much of an issue with it, though. I have a black interior and 17% tint. The tint helps a good bit. I doubt 50% would do much. Anyway you can cut down from light hitting the screen the better. I think the best angle would be directly infront of you obviously.

**Arathranar** · 10-07-2004, 01:21 AM

I found something pretty similar. The best angle was somewhere around 10-20 deg up but facing directly down the middle of the car (i.e. not angled towards the driver at all left/right). If I angled it more vertically I got light from the rear window. If I angled it more up, I got light out the front window.

I'm just wondering how well angled the many attempts at the 'stock' look end up being. If I tried that in my car, it would be too angled towards the rear window.

**Arathranar** · 10-07-2004, 01:22 AM

... and if I angled it left towards me, I got more reflection from the drivers side window.

**Arathranar** · 10-07-2004, 01:39 AM

I had a discussion with the guy at work who's working with lcd manufacturers to improve lcd quality (one of the major problems being brightness/reflections).

A couple of interesting data points.
1. A good rule of thumb is that typically 4% of the ambient light will be reflected back by a surface.
2. Both sides of the touch screen surface do this.
3. Ambient light is easily 20x as bright as the back lights meaning 4% = the brightness of the back light and you can see nothing
4. 100x isn't unusual for ambient light.
5. The trick car manufacturers do for car dials is two fold - have a hood over the dials to keep out direct light; have a curved plastic shield in front that causes the angle of reflection to be such that light coming from the hood would be reflected into your eyes (i.e. most light doesn't get reflected at you).

If you don't want to use a touch screen, a piece of plexiglass held in a curved shape could do the same for an embedded lcd. The space for the curve would necessitate something of a hood as well.

I wonder if it's worth it. I imagine it would be hard for someone with a lilliput or Xenarc that's not yet installed to mock that up. I don't have one otherwise I'd try it.

Given where I hope to mount an LCD (currently planning for a 10.4" on a rotating arm so it can fit in the dash but be moved out to a suitable viewing orientation), a hood might be possible for me if I decide to go down the Xenarc route instead. The curved plexiglass front might even be possible if I were lucky with space and could come up with a suitable tilting mechanism. Hmm...

The LCD I got (off the guy above in fact) is a 10.4" 1024x768 but only 180 nits bright. It's perfectly legible on a normal bright but not sunny day *if* I have the optimum mounting angle as above. Otherwise it's unreadable.

**nirvanades** · 10-07-2004, 02:18 AM

I think glare is just part of the whole thing...

**Arathranar** · 10-07-2004, 02:32 AM

It is. The other part is ambient light (i.e. non-directional). What I'm interested in - is how much of the visibility problems people are complaining about is due to directional light versus ambient. That's where the correct angle of the LCD would matter. Is a lilliput or Xenarc usable even on a bright sunny day *if* angled such that if it were a mirror, it would basically be showing you the roof of your car... Most of the nice 'stock' installations I've seen pictures of on this forum look like it would be most likely showing you the back window almost perfectly...

**Diggy** · 08-21-2005, 03:51 AM

I am surprised that you are not having Anti-Refelction(AR) films installed on your displays. These will knock down the 4% reflection surface to <1%. It can even be applied to touch panels though ideally there would be 3 layers installed (one on the front of the touch, one on the back of the touch, and one on the LCD, this would reduce your reflection by 9%. Better yet. for optimum performance optically laminate the touch panel or a piece of anti-reflection glass to the LCD.

There is more informaiton at;
http://www.fpdsolutions.com/content/view/42/2/

~dig

**the_realscott** · 08-21-2005, 04:16 AM

Yeah, I'm new to the whole car pc thing... I'm thinking of doing it, and I've planned out a system to integrate all this stuff into my existing stereo system, but the one thing that's stopping me is the screen. I've never seen one of these screens in a car before so I just cant bring myself to cough up all that cash only to find out that it all either looks ****, or is invisible during the day!

PS: Anyone from Melbourne, Australia, that wants to show off their setup? (: