800X1280 narrowscreen???

**turbocad6** · 10-07-2005, 10:59 AM

Originally Posted by Vinister

How come in your pictures the laptop screen on the left looks much brighter than the LED creation? Why not just use that screen instead?

that picture is with 20 leds, final will be 32..... it's also no where near as bright although it may look that way in the pictures because the color is so much better on that laptop screen....

that modded screen lights up the room..... the laptop is not even close.....

the color is the main difference.... the screen in that picture still has the heavy red cast from the copper & I played around with gamma..... in person you can clearly see the brightness difference though..... major difference, that laptop also happens to have a really nice display btw

one of my concerns with a screen this bright is color washout..... but that's really only a problem when really cranked up...... if the choice is to either see nothing during the day in sunlight or see a washed out screen, I'd rather at least be able to see it, which is the whole reason for this in the first place....

under normal conditions this screen will not be cranked up all the way, so this isn't much of an issue.... after this is in is when I will have to start working on the auto dim with photo sensor

**turbocad6** · 10-07-2005, 11:01 AM

also with the better dispersion of the 32 led's over the 20 I will need less diffusion, which will also increase the brightness

**turbocad6** · 10-09-2005, 02:26 AM

these led's are awsome if there spaced right, the first test was with not enough leds to give total light coverage & needed a lot of diffusion

I then set out to fill all the dark voids with leds

I left the original pattern upgradeable, good thing too because now it is PERFECT

spacing & distance are the two main variables that will allow an even light distribution without need for excesive diffusion, the upgraded patern looks like this, this is with no aditional diffusion other than a sanded freznel lens.... the original pattern had hot spots so bad that I needed to add a sheet of paper to get good dispersion, but this also cut the light down quite a bit

now this thing is BRIGHT

this is the lcd lit with no display

**turbocad6** · 10-09-2005, 02:34 AM

this picture is AFTER I blew out one of the three power supplys for these led's......... there are only 21 lit..... the whole top three rows of 11 more are out completely in this picture........

remember, this is only the bottom 2/3 lit.... 21 on & 11 off ...... the laptop is cranked full bright for comparison

here you can clearly see the even light distribution & how much brighter it is, the top of the screen is slightly darker because of the above mentioned problem

**turbocad6** · 10-09-2005, 02:46 AM

now I will have to play with color & gamma..... of course this screen won't be run at full brightness all the time, when I turn the brighness down the colors are crisp & the display is really nice..... the dell 700m's have a nice display to begin with, I'm going to build an auto dim circuit with a photo sensor......

when it's bright & sunny out, & the tinted windows are down...... I should still be able to see this screen,,,, sucess!!!!!!! as that was the main goal for this backlight......

**turbocad6** · 10-09-2005, 02:57 AM

I've looked at some stupid expensive screens that are used in helicopters & such.... all things considered if this whole thing came in at a grand belive it or not it's a BARGAIN.....

as far as sunlight readable displays go, this is NOT expensive.... add to this the fact that it's an lvds screen directly run off my motherboard.... AND the fact that it fits my dash perfect..... AND the fact that it is pretty unique.... I don't regret one penny spent here really

**alti** · 10-09-2005, 03:53 AM

damn, that looks good. Can not wait to see it at the meet. And you are right on the cost, my allbrite sold for over $1500+ when it was new. And I do not have the dimming capabilities you do (although i might start looking into rigging something up). Plus you get the gratification of working on a project like this and learning along way.

and the fact that it is liquid-cooled is ridiculously cool.

**alti** · 10-09-2005, 03:58 AM

what are you using for diffussion, just the sheets the screen had stock?

**turbocad6** · 10-09-2005, 11:40 AM

the lcd has everything it came with, minus the rearmost layer which was a reflector for the stock tube & not transparent. the only add'l diffusion is a freznel lens that I sanded with 80 grit to aid dispersion.... I still have this reflective layer & was thinking about using it in the box. I would cut holes for the led heads to poke through them. this may help a little more although now that the box is all white inside it may not make a huge difference..... it will cover the black of the led's themself & the wiring, but I did all the wiring white too so again, maybe not much different........

I also thought about adding a mirror here instead.....with the led heads poking through.... but it would have to be almost paper thin to not affect the radiating pattern of the led's. if I could get a mirror in there it may help under high ambient light conditions by acting transflective, but I don't know how it would react by being about 1 1/2" back from the lcd itself, that would be pretty experimental & I may play with it when all else is done....

I tried it without the freznel also & it doesn't make much difference, it also doen't cut much light at all so I decided to use it.... it will also aid in keeping any radiated heat from the lcd by insulating/isolating slightly

this is the inside witout the lcd or freznel

**turbocad6** · 10-09-2005, 11:44 AM

this is with just the freznel....

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