So, give us new LCD touchscreen options!

**Scouse Monkey** · 04-27-2005, 09:38 AM

Willow, thats all very well placing your screen somewhere it is shielded - i think every memeber is trying to do that but it is also hard enough for most people to find somewhere to mount the screen. My car was designed when satnav in such car was unheard of so no provision was made for it. Also, it is not that common for OEM to have touchscreens. All the BMW, Audi and Mercs I have been in have had soft buttons around the screen ot idrive style controllers. I did see a new car with a TS the other day.

Pug 407 for example has a nice screen high up that is JUST viewable but it has about 1 million buttons further down to do stuff - that is not very safe.

i have used a little TomTom attached to a window. That has a TS and sits right int he window. as long as you point it right at you there is no problem as it uses filters on the screen to refuce the angle an dincrease the intesity. Like lookin at a high brightness LED or a wide angle one. Both sue the same power but one hurts you eyes and can onyl be seen properly from straight ahead.

Alsp, current screens are to bright at night if you mount them high up.

if you look at aircraft displays they are of the order of 1000nit. Some Panasonic toughbooks are 1000nit. Tansreflective is the best way - too a point but its not perfect. As i sead with when you have the screen backlit by the sun - as you get in plane cockpits. When your eyes are fully adjusted to the bright sun you will not see your screen. It is not all about glare.

This mod is to help but to get the best viewing there are lots of things to do that all need to be done.

**kenop** · 04-27-2005, 10:26 AM

phew.. nice 17 page read... subscribing to be kept in the loop. thanks for the great research guys.

**jcdillin** · 04-27-2005, 10:49 AM

The only thing that you should have on the back of the LCD should be the polarizers/diffusers. I would remove the plexi light guide, and remove the stock CCFL. so then all you should have is the glass and a few sheets of diffuser. Then I would take and get the back of your box as white as possible, for that matter I would even make the whole thing white inside. So that you can reflect as much of the ccfl light as possible. Your probably going to have to expiriment with the position of the ccfl's, they might work better all the way against the back and they also might work good halfway up.

But after the find the bulb your going to need it should list all the startup and run voltages. then you just give that to someone like ERG and they will let you know of the proper inverter. I was going to order the straight bulbs from digikey at first. But 8 bulbs at $10 a peice, ouch

Originally Posted by turbocad6

scouse...the rear layer that reflects the original backlight has been removed...my thoughts are to let more light in from the rear....I cut out most of the back so I'm thinking that I may not even need the original tube for illumination...possibally only if the edges are a little dark. I thought about leaving the rear reflective sheet in place also, as it is not totally light blocking...but I thought it may block a lot of light..do you think I should have left it in? as far as the box & confussion, here is a shot of it all assembled.....as far as the distance & depth...I needed the depth for the board that had to be folded back, but that doesn't mean that I couldn't move the bulbs closer to the lcd...I also thought of putting a mirror reflector behind the tubes to try to get as much front projection as possible......I'm hoping that I can contact one of these vendors & have them tell me what I need.....if I have to do all of the calculations myself then I'm going to have to learn more about this stuff as far as start up voltages & formulas for calculations...I'm hoping I could just tell them that I need the power supply for 16 bulbs & I need 16 bulbs that are approx 10" long......can it be that simple or am I just oversimplifying it........I want to just order what I need & get to the dash fabrication done

I did notice that the screen looks like crap without the rear reflector layer as most of the orig. backlight is projecting out of the rear of the panel at this point, but I thought that was a good thing at this point...also the viewing angle has decreased with the rear reflctor removed so I guess backlight does play a part in viewing angles...if only in the fact that well lit helps on a view on an angle.....

**turbocad6** · 04-27-2005, 11:07 AM

scouse got me confused...I don't see why you are saying to leave the rear reflective layer in place.....now keeping it & mounting it behind the new tubes...that I can understand.......

jc, as far as removing the plex light guide I considered that, but it holds the lcd togeather so well that if I removed it I would have to replace it with glass or plexi the same thickness...I didn't think the difference was worth the effort....

**jcdillin** · 04-27-2005, 11:53 AM

Originally Posted by turbocad6

scouse got me confused...I don't see why you are saying to leave the rear reflective layer in place.....now keeping it & mounting it behind the new tubes...that I can understand.......

jc, as far as removing the plex light guide I considered that, but it holds the lcd togeather so well that if I removed it I would have to replace it with glass or plexi the same thickness...I didn't think the difference was worth the effort....

well as long as the plexi doesnt have little dots on it that grow in size from end to end you should be fine leaving it. but if it does it will cause uneven light.

so you should end up with

Code:

lcd glass                               ---------
diffusers                               ---------
plexi                                   ---------
new ccfl                               ()()()()()()
old reflector from back of plexi       ---------
back of metal box                      ---------

**Scouse Monkey** · 04-27-2005, 12:27 PM

yeah nice one Jerry, was gonna draw him one of my famous pictures!!!

EDIT: turbocad, one of the diffusers might be relective. Sometimes on the LCD side to shine light back. sometimes on the CCFL side to shine light back hitting it at an angle back to the rear reflector so it can reflect out at a more perpendicular angle to the LCD.

**turbocad6** · 04-27-2005, 01:56 PM

I've got to take it apart & check.....I think it did have little dots, but I thought it was more of a difussing pattern.....I will look at it again.....I should be able to replace it if it is going to make a difference....also concerned about the frame for the original backlight.....don't want to fully remove it because it to holds everything in place.....

**Scouse Monkey** · 04-27-2005, 02:07 PM

Screw me! 248 posts!!!

The dimple pattern on the plexi is to allow the light bing carried by it to break out. Like if you get a piece of plexi, put an LED agaisn tthe edge and the then you can see any surface imperfections as the light escapes.

All we are doinf is keeping the original backlight case and removing the plexi and the original CCFL. Then filling the gap with more CCFLs. If we need to we will put the plexi back cut to fit the new CCFLs.

**jcdillin** · 04-27-2005, 03:13 PM

yeah i'll have to find the pic of the plexi from the lilliput, but it has no gradient, it has small dots over the whole surface as the ccfl wraps around the plexi

**phc** · 04-28-2005, 12:46 AM

Looks like a fun project. Did you check out the Lamina LEDs? You can get them at Mouser, just fill the back of the LCD with those suckers, get real bright.

If you have the cash, check out Boland Communications. I've seen one of their Daylight HDSDI screens about a year ago (about $5K), very nice. They also make some that will do PC inputs for about half that price.