Re: Color/Grayscale LCD Fundamentals

From: ZO (ZO_at_antispam-yahoo.com)
Date: 12/24/03 

Date: Wed, 24 Dec 2003 02:11:59 GMT

Are you sure it's not expecting *analog* RGB?

"Ian McBride" <ianmcbride2003@yahoo.com> wrote in message
news:tvDDb.1034$Ts5.951@newsread2.news.atl.earthlink.net...
> I'm trying to understand how color and grayscale LCD controllers work..
> bear with me..
>
> Looking at a couple of LCD panels, they have row and column drivers, with
1
> bit per pixel, usually organized as R-G-B, R-G-B, etc. This implies
> "hardware" support for 3 bits-per-pixel. However, controllers discuss 8,
> 12, or 16 bits per pixel. I assume this is done by PWM techniques across
> multiple frames, but given the scan rate of most panels, even this seems
> impossible. If I have a panel with a max scan rate of 120Hz and I connect
> it to a SHARP ARM/controller with 65536 color levels, the best I could get
> with my "technique" (without flicker) would be 2 color levels, which still
> doesn't work out..
>
> So.. my question is this: how does an LCD controller get 4096 or 65536
> colors from a LCD display? Similarly, how does an LCD controller get 4 or
> 16 levels of gray from a LCD display? I'm reading through data sheets but
> somehow I'm just missing something very fundamental..
>
> Thanks!
>
>