Re: [NTLK] News on my trusty ol' OMP

> Well, I was working on a backlight as well, but
I guess Frank beat me to it.

It wasn't my intention to beat anybody to anything
:-)

I was (and am) under the impression that this
project was intended as a joint effort. Actually
the result WAS kind of a joint effort since the
pdf by Stuart Kurtz that I found at Ryan's MP100
backlight project page provided valuable info that
made success much easier.

> Hopefully Frank will detail how to do it.

I sure will. Currently there are still some
problems that must be ironed out:

1) There is a reflective backing foil glued to the
back side of the LCD. Without it the LCD would be
transparent and you would be able to look through
it, which would reduce contrast to almost zero.
This backing foil must be removed and the
backlight must take its place. The foil is glued
to the LCD with a very sticky glue. It requires
time, care, patience and much gentleness to
remove the foil without breaking the LCD.
Unfortunately the glue remains on the LCD, not on
the foil. This means that the backlight will
actually be glued to the LCD, which isn't the case
with the 2x00 and eMate.
The result is that the glued area appears somewhat
darker than the parts that aren't glued. This is
why in my images the screen appears brighter at
the edges and in some spots where the backlight
foil doesn't stick properly to the glue.
The result would be much better if it was possible
to remove the glue without endangering the LCD.
This would also make replacing the backlight
fairly easy. I am not sure if and how the glue can
be removed, and I do not want to sacrifice my
display. If someone happens to have a MP100 or OMP
display lying around that he does not need, I'd be
interested. A broken LCD would be sufficient, and
it needn't have the digitizer.

2) A backlight foil needs an inverter that
generates about 100 Volt AC voltage required to
drive it. That's the black thingie with the white
sticker below the 9 Volt battery that you see
here:

http://www.pda-soft.de/us/temp/ompbacklight06.html

There is no room to put this thing INTO the Newton
unless one would sacrifice the battery compartment
(into which it would fit quite nicely). But the
usefulness of a PDA without a battery is somewhat
limited in my opinion. Apart from that the
inverter's operating voltage is not without
danger. You'd have to isolate it properly to avoid
damages to the Newton or to your health.

3) Powering the inverter would be no big deal. It
can be connected to the battery contacts via a
small switch.

4) I heaven't measured the power consumption yet.
This might be an issue. But this issue would
probably be compensated to a certain degree since
state of the art AAA size rechargeables have more
than twice the capacity of Apple's original cells.

5) You can do terrible things to a prototype. But
if you do not want to endanger your Newton or its
users, you wouldn't get around using a custom-made
backlight. Usually the AC voltage contacts are
located at one of the backlight's edges. This,
unfortunately, is where the metal digitizer frame
is.
In my "prototype", which I'd rather call a
proof-of-concept-type, I had to grind parts of the
metal frame off and isolate the contacts
thoroughly with melting glue to be halfway on the
safe side. The actual backlight was one salvaged
from a broken display that originally came from a
MP120 that Dr. Newton alias Dave Watson alias
Digital Ocean Dave fitted with a backlight. So
don't throw your broken MP130 / 2x00 / eMate LCD
away yet. Maybe one day it'll enlighten your OMP
or MP100...

Frank

-- Newton software and hardware at
http://www.pda-soft.de

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Received on Wed Apr 1 20:08:14 2009