I removed the glass LCD panel on a 16x1 display so I could peel off the reflective coating and install an electroluminescent backlight.
I noticed that for a while, as I touched the contacts with my fingers I could trigger some of the display segments to turn on briefly.
I let the panel sit for a couple hours and the effect is gone now. Guessing that the capacitance between the "sandwich" stored enough charge from when it was receiving power to power it for a bit, even after it was disconnected?
I've seen the same with panels pulled fresh from storage packaging. Maybe you'd discharged yourself.
It takes virtually no power to move the crystal alignment. Just moving nearby objects is enough power. That's why LCD watch batteries run for
5+ years.Overvoltage or a persistent DC voltage may get a charge stuck in the panel for a while. Give it a few hours and it will recover.
Thanks for the explanation. And I just realized I did the "ATM machine" thing with the subject of this post...
Well, it _was_ 01:20 AM in the morning...
That adhesive stuff can produce a strong electric field when peeled off. I suspect you were seeing the effect "soakage" charge in the glass.
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