 PRS600 screen backlight/touchless screen mod
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Conundrum
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Wed Apr 14 2010, 06:54AM
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Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062
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Hi all.
Currently working on my PRS600.
Upon dismantling the broken unit I purchased for the front panel, I determined that the
screen format is the same (i.e. large areas with no metal backplane covering the glass)
Shining light through it revealed that it could be backlit for reading at night, unfortunately the EL I bought is too small (1cm*4cm)
Any ideas where I might get some green EL or OLED film which can be cut to size? i know its moisture sensitive but this may not be an issue due to having access to a laminator.
As for the touchscreen (hint:- reflections = BAD BAD BAD) this is a standard 4 lead resistive panel.
I have a spare panel from my damaged front pane so could use this on a small LCD as is, but my main reason for removing it is to construct some PIC based circuit (most likely using a 32.768 kHz crystal for low clock rate) and a digital compass IC to detect the presence of a stylus about 1" above the screen.
the presence of those magnets for closing the screen case could be annoying, but helpfully Sony left enough space between the backplane and case to install the sensor close to the screen surface.
alternate ideas include using four or more small linear HE sensors (which draw in the microamps) and determine stylus location based on the readings.
Interestingly these sensors can be removed from pretty much any broken BLDC motor such as one from a VCR, and if you are lucky aren't even SMD but very thin leaded package.
these sensors are typically used in 5 1/4" disk drives so go mining...
the output is typically 2.5V and outputs go in different directions depending on the magnetic field strength (i had one detect a mains transformer from nearly half a metre away!)
used one for making an EMF meter but the main problem was the lack of sensitivity above 50 Hz.
Shame as it would have made a great diagnostics tool for those dead flat screens I keep acquiring.
EDIT:- now my Reader has no more sucky gouge marks on the case :) :) i can use it again.
still hate that touchscreen affecting the contrast though.
Memo to self:- get better case, certified UL and DoD to be girlfriend proof.
interesting?
-A
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