A lot of people seen to think that they can easily interface a laptop monitor to their PC. While it is possible, most people don't have a clue what's involved. While some LCD panels have built-in controller, most, including ALL laptop displays DO NOT. There are no smarts on the LCD panel at all, just row and column drivers.
Many of the links to the EIO pages are broken. I'm going to leave them up for a while, but, if they don't return I'm going to delete them from this page. They have done a lot of updating to their site which is now at www.shopeio.com. It doesn't look like any of their forums made it to the new domain.
You might want to read this web
page on the EIO web site. www.eio.com/lcdconnect.htm
It is a collection of posts to
the EIO LCD forum on the subject of using laptop LCD panels as a monitor
for video or VGA. Some of the posts were made by myself and some
were posted by other knowledgable people who want to help keep the forum
going. You might also want to read DJ's
post the the EIO LCD forum. Here's another informative post
by DJ.
Below is a picture of a LCD controller based on the Sage Inc. Cheetah4 chipset. Sage Inc. was bought out a while ago. They are now part of Genesis. The bottom right corner is the on board power supply. It takes +12V in and generates +3.3V and +5V. In the bottom left is a daughter board for input interface. This particular daughter card is for DFP (Digital Flat Panel). DFP is an earlier version of what we now know as DVI. Only the connector has changed. DFP and DVI share the same TMDS signalling. DFP was only capable of single link which limited its resolution, that's why DVI was developed. DVI uses a connector with more pins to accomodate two TMDS links as well as analog VGA. The daughter card in the upper right corner is the panel interface adapter board. There are lots of different LCD panels out there and there LOTS of different interfaces. This board provides three output connectors. I'm using connector #1 & #2 for my Mitsubishi panel. In the upper left are two chips with stickers on them. The upper one is an 8 bit microcontroller (80C32) and the chip directly below it is the program code storage flash memory for the microcontroller. The code that is currently in the flash memory is specific to the LCD panel that is connected. If I were to change to a different panel the code would most likely need to change as well. This code change would need to be made by the controller board manufacturer. The microcontroller basically writes parameters into the Sage controller chip to configure it for the LCD Panel (H/V resolution, H/V refresh timing and blanking, etc.) The cable coming off the left hand side of the board supplies power to the CCFL backlight inverter.
The picture below is another panel
adapter board. The pinout off the first panel adapter daughter card
only got me close. This second board got me to the point where I
can use flat flex cables directly to the panel without doing any fancy
wiring. The pins on most LCD panels are very close together and soldering
to them would be very difficult. Having a board that maps the signals
to the proper connector so that standard flat flex cable can be used is
a must. You can see in the last picture that from the second board
it's a simple connection to the panel. I think one of the cables
is 30 lines and the other one is 40 lines for a total of 70 connections
to the LCD panel. Most of these are ground with a good number for
power and about 27 for the LCD signals.
The picture below is of the entire design. Here you can see the LCD controller (bottom left), interface board (bottom right), LCD panel input connector, CCFL backlight inverter (top left).
