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Picture of  DIY LCD backlight
This simple method lets you make LCD backlight of any color and size to bring new look to an old device.
 
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Step 1: Let's make something.

For this job you'll need piece of transparent plastic, LEDs, resistors and some wire plus good set of different tools and couple of straight hands ;-)

Step 4: Oops! Don't rush! Think first.

Picture of Oops! Don't rush! Think first.
My mistake was that I've removed polarizing filter together with reflective film.
If it happened just use sharp tool to separate them and save filter to put it back later.
See wiki for details.
http://en.wikipedia.org/wiki/Liquid_crystal_display

Step 5: Get it cut.

Picture of Get it cut.
Next cut rectangle piece of plastic.
Sand face and back sides of plastic plate with fine sandpaper to diffuse light then cut notches on sides of plate where you plan to install LEDs.
Shape of LED should be formed with file to fit into the notch

Step 6: Let's practice some LEGO ;-)

Picture of Let's practice some LEGO ;-)
Something like that.
You can use hot glue to secure it on place.

Step 7: Let's give it a trial...

Picture of Let's give it a trial...
Not bad for me ;-)

Step 8: Bring all bunnies into the cage.

Picture of Bring all bunnies into the cage.
Now everything is ready to be assembled:
-PCB;
-white sheet of paper to reflect light back;
-polarizing filter (if you removed it by mistake);
-plastic plate with embedded LEDs;
-glass assembly;
-frame.

NOTE:
Be very careful with golden pads on PCB and elastomer connector (zebra strip). Use pure alcohol to clean it if you touched contact pads with your fingers.
Another important thing is proper alignment.
If after powering it up you got missing lines (characters) on LCD then connector has shifted from original position. Carefully take it apart and re-align it.

Step 9: Final step.

Picture of Final step.
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I hope you already calculated value of resistors you need.
So, solder it up.
There are two points to get power to LED from.
You can connect it directly to logic power supply (pin 0 - GND, pin 1 - 5V) of LCD.
Or you can make separate connection(on my LCD there were unused pads for optional backlight) and in that case you'll be able to use PWM signal to control brightness of LED.
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Motorcityguy3 months ago

I would really like to do something like this for when I retrofit an antique radio with the dial. Where can I get the supplies for doing this?

AP Digital light (author)  Motorcityguy3 months ago
You need LEDs and transparent acrylic. Try your local electronic hobby store.
remzparadise11 months ago
real good ill put this on mu diy proyects 4 tomorrow!!!!
Another tip —
If you wrap the edges of the plastic/plexiglass with shiny material (aluminum foil/tape) it will reflect the light back into the plastic and create a stronger, and more even, backlight.
This was discovered after dissecting an LCD from my clock radio and seeing how they did it.
hyaki3 years ago
thanks man!! ;)
hyaki3 years ago
Hello,
Very cool tutorial!
I have some question:
Where did you get that plastic plate?
Can I buy Online with custom thickness?

Thanks
AP Digital light (author)  hyaki3 years ago
It's a piece of regular 1/8" acrylic that I've found in my scrap box;-).
You can use any kind of transparent plastic.
There are lots of online plastic suppliers who offer custom cut material of any size. Standard thickness 1/16", 1/8", 3/16", 1/4", 3/8",1/2", 3/4", 1".

i tried this with a transistor radio and cracked the board opening it
how hard is it to find one of those? ive always wanted one.
Your Smart.

You're a D-bag
JK
Aren't you perfect. Smartass.
>clap clap<
Good comeback
Chromatica4 years ago
Cool.
First LED project?
junits154 years ago
where can I learn how to use an lcd display?
AP Digital light (author)  junits154 years ago
There's lots of info around web.
You can start with this free "PIC microcontrollers" book
http://www.mikroe.com/en/books/picmcubook/appb/

If you need more examples just google "LCD interfacing".
thanks
rami1234 years ago
very nice!!!! i go to add backlight to 11 controls of Air Conditionals in my house! i think to use SMD Leds
Just wondering if anyone in here had experience gluing a layer of glass on a LCD screen with UV glue? If so, I would love some advice on how to do this with little to no spill-over so that it doesn't get into the circuit board components that are around the edges of the LCD screen itself. I have heard there are issues with applying pressure to the LCD screen with anything heavier than just the glass itself so I was wondering how to calculate the right amount and placement of the UV glue if I cannot apply any pressure to spread it out....
Picture and text show polarizing filter below the plastic lighting plate (if you removed it by mistake). If the filter had not been removed it would be above the plastic lighting plate. What is the reason for this layering change or is this a typo?
Good catch. Filter should be above lighting plate.
e22karol6 years ago
It looks goods
NJB6 years ago
Very Nice! I'll have to try this with my old GBA if I can muster the courage to meddle with it's guts... (and find it in the first place!) A thought for the analogue meter, if you replaced the Backlight LEDs with UV LEDs and then coated the needle in UV-reactive paint (or a mixture of glue and glow powder) then you'd easily be able to read the value even in the dark!
AP Digital light (author)  NJB6 years ago
Nice idea with UV needle. Thanks.
humexavier6 years ago
can you make A LCD DISPLAY OUT OF LASER TRANSISTORS OR A LED LIGHT change colors faster with a LED laser diode to work like other light sources?
AP Digital light (author)  humexavier6 years ago
Narrow laser beam is not well suited for illumination of large area but for some kind of effects it can be used.
Whatnot6 years ago
Not to quibble but the reason old analogue meters have the reflective strip is so that you can line up your eye with the needle and its reflection and thus avoid erroneous readings caused by the distance between the needle and the scale and the angle at which you look at it. Not that that always matters but I thought it might be an interesting titbit.
Have to admit I never wondered (enough) what the reflective bit was for. Now that I know, it's an elegant solution to an obvious problem. Thanks.
pcairic Whatnot6 years ago
The word you are looking for is
parallax : the apparent displacement or the difference in apparent direction of an object as seen from two different points not on a straight line with the object; (Merriam-Webster)
Whatnot pcairic6 years ago
Not quite, although I could have used parallax in the description it would not do on its own and I was deliberately more liberal with words to make it clear anyway. So I wasn't really looking for the word parallax :)
pcairic6 years ago
Great instructable! I wish there was a way to make the light reflect more evenly.
AP Digital light (author)  pcairic6 years ago
I agree. So, more research to conduct. Thanks!
CameronSS6 years ago
Why bother diffusing both sides of the plastic? If only the front side was diffused, wouldn't less light leak out the back? Apologies if I sound ignorant, I haven't done much work with optics.
AP Digital light (author)  CameronSS6 years ago
I'm not optic guru too. It's matter of experiment. LED emits narrow beam of light and you have to try different combinations to get even illumination and maximum brightness.
hondagofast6 years ago
How easily could you replace the florescent backlight tube in the LCD screen for a laptop with LEDs? They are the biggest power hogs on any laptop...
AP Digital light (author)  hondagofast6 years ago
I think it's possible but some research work is required. 1. Select white LEDs with proper optic characteristic. 2. Fit them into the room which is provided for a slim CCFL tube. 3. Give it long test run to check if eyes will feel good after several hours of staring at new screen. ;-)
It's been done many many times, time and time again. Don't bother googleing, just do a search Here
That link doesn't work. :P
*shrug* Does for me
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