About negative mode LCDs

Dimitris1976 · 03-31-2002, 04:11 PM

I am looking for a parallel, 20x2, red or amber colored, character LCD module in negative mode.
Are there any TRANSFLECTIVE ones in NEGATIVE (bright characters on dark background) mode?
All the negative mode LCDs I've found (Crystalfonz) are of the transmissive type. I have been told that transflective LCDs are much better in sunlight and their back light doesn't have to be constantly on.
Is there a way to turn a positive transflective into a negative one?
Do you know where I can buy such an LCD module (descent prices too)?

jol · 04-01-2002, 03:44 PM

Quote:

Originally posted by Dimitris1976
Is there a way to turn a positive transflective into a negative one?

I think it's arby who mod lcd's and changes the background, I really dont want to use this phrase, but search the forum...

since i feel bad for telling you that, I searched it myself and look here

one

two

send him a pm, i'm sure you could make a deal

Dimitris1976 · 04-01-2002, 04:01 PM

Jol,

thank you! You seem to be the only one bothered to reply to my question.
Unfortunately, I have already searched and I can't find an answer to my question. The LCDs Arby used to sell were green, transmissive and 40X4 - way to big for my needs.
You helped me though 'cause now I know that if I find a transflective, red, positive one, I can reverse it to negative mode with a polarizer filter.
I just don't know where I'll buy all these from...

MP3DUB · 04-02-2002, 10:47 AM

CrystalFontz make an ungodly number of coloured parrallel lcds in all shapes, sizes, and colours (http://www.crystalfontz.com/products/index-std.html). Being that they are parallel, you would either have to wire it to a backpack by yourself, or do what its designed for

. And polarizing film can be aqired at Edmund Scientific (http://www.edmundscientific.com/). And arby's mp3box page has a good guide on how to change the film. Its also be suggested that camera stores might carry polarizing film.

milesg · 04-02-2002, 01:50 PM

You can also get polarizing film at http://www.polarization.com/shop/catalog/index.html

One thing to note, is that some LCDs do not inverse well... Meaning that you'll get faded brown background and not-so-bright characters (at least with the green LCDs that I've played with). This has to do with the quality of the Polarizing film that comes with the LCD, the film that you replace it with, and how it interacts with the Liquid Crystal in the glass.

Unfotunetly the only way to see if it works with a specific LCD is to actually do it. The Seiko LCDs available at http://www.eio.com used to be very good for inversion (they're sold out now)... The ones I had trouble with were the Densitron LCDs from http://www.digisys.net/timeline/. I hope that the CrystalFontz LCDs give you better luck.

Here's a link to Arby's Inversing tutorial:
http://mp3car.com/usersites/arby/screen.html

Good Luck,
-Miles