Is it possible? TFT Panel Question.

[David Baxter]

Hi group,

New to this newsgroup, so I hope I've picked the right place to ask this
question! If not, plese spin me around and point me in the right general
direction and I'll trundle off that way.

I have a rather odd request. I'm trying to build a driver circuit for a
TFT panel I pulled from a laptop, just to see if I can.

The video signal requires 3.3 volts on each channel (R,G,B). No problem.
A simple matter of building a l'il circuit to step down from the supply
voltage to 3.3 volts. But, the backlight requires 1300 volts, which is
meant to be provided by an invertor. Now, my electronics knowledge is
very very rusty, but to me, an invertor would be something that flips a
signal:

Before:

__|¯¯¯|__


After:

¯¯|___|¯¯


As I don't have the invertor, I need to build something to replace it.
The original invertor would've originally been powered by a 11 volt
battery, which would obviously be DC, so I don't see how it could "invert".

Anyone got any suggestions?

There's a spec sheet here: http://www.eio.com/lp141x2-b.pdf


Cheers,
Dave

 

[CWatters]

the backlight requires 1300 volts, which is
meant to be provided by an invertor.

Can't you extract the inverter from the laptop? Sometimes it's a little PCB
on it's own.

 

[Mike Harrison]

The video signal requires 3.3 volts on each channel (R,G,B). No problem.

I don't want to dampen your enthusiasm, but, if the datasheet is for this
panel, you do realise that this is a 'Panel Link' sort of panel - the data
is sent using multiple differential LVDS channels. You will need to generate
signals at (IIRC) 7 times pixel clock, ie 460 MHz. There are chips that do
this but a fair bit of work is involved ...

Compared to this, the backlight is easy ! You could always remove the
backlight assembly, and put a bright light behind...

Dave

TFT panels changed to using LVDS around the 800x600 generation - you can often find 800x600 panels
with simpler logic interfaces, or lvds ones with an easily identifiable lvds receiver chip you can
either remove or drive with the corresponding transmitter chip.

For an easy,cheap source of CCFL inverters look at PC neon case lights