2x16 Character LC display. Originally reflective kind. The reflector foil was peeled off from the back of the LCD.
In order to make it a negative kind LCD (characters show background light, everything else is black), The polarizer foil was peeled off from the front glass of the LCD. In the picture you can see the polarizer in front, with glue remains.
This is how the polarizer was originally.
and this when the polarizer is turned around (upside-down). It basically inverts the display.
Have you ever wondered why most LCDs look green ?
again turned upside-down
Getting the glue remains off is the hardes part of the display conversion. I first tried label remover.. didn't work too well. Then I tried spirit (for Germans: Spiritus). It tooks some work, as it had to be gently rubbed off, similar to how you'd polish your car.
Here's the result :)
A white-on-black character LC display.
another shot.
First try with red LED backlight... backlight should be even, not like this.
==> We need a diffuser.
Here with diffuser. I used a scrap piece of 3mm white copolymer (PETG). Even though this is quite thick, it comes out great.
Here's the display on top of the PETG diffuser on top of a bunch of red LEDS.
This shows the sandwich from the side: breadboard with LEDs (10x 3mm), then the 3mm copolymer diffuser piece, and on top of that the LCD.
The same thing with lights on. The contrast looks good.
