Author Topic: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?  (Read 5996 times)

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Offline dentakuTopic starter

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I have one of those extremely common 16X2 LCDs that came with an Arduino starter kit.
It's blue with white letters because the backlight is white.
http://www.electronicoscaldas.com/333-large_default/display-lcd-16x2-el-1602a.jpg
It's held onto the PCB with 6 twisted metal tabs.
http://www.wayengineer.com/images/TFT/YX-1602A-1.jpg

If I open it up to see if I can simply flip a polarizing filter to reverse the colours will it be impossible to get everything back in the right position so the zebra strip connects properly?
Is there a thin polarized sheet in there like I'm assuming?
 

Offline free_electron

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #1 on: February 14, 2015, 09:03:28 pm »
the polarizer is typically glued to the glass. won;t work
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Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline wraper

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #2 on: February 14, 2015, 09:04:00 pm »
First of all it almost certainly is glued to the glass. Secondly you need to rotate the polarizer by 90o what is impossible because display is not square.
 

Offline dentakuTopic starter

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #3 on: February 14, 2015, 09:13:16 pm »
First of all it almost certainly is glued to the glass. Secondly you need to rotate the polarizer by 90o what is impossible because display is not square.

Doh! You're right. I should have realised that  :palm:
 

Offline Whales

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #4 on: February 14, 2015, 09:37:27 pm »
If you have an old computer/laptop screen you don't care about that's lying around, a piece of the polariser can be cut out by hand.  If you disassemble one the various layers fall out like a disused sandwich.  I've used this to repair small LCDs with water-damaged polarisers before.

Offline elgonzo

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #5 on: February 14, 2015, 09:51:33 pm »
First of all it almost certainly is glued to the glass. Secondly you need to rotate the polarizer by 90o what is impossible because display is not square.

Rotating the polarizer 90 degrees is not necessary. Just flipping it front-to-back should do the trick (assuming there is no glue involved).
When i was a kid i had a calculator whose LCD polarizer and glass were not glued. Long story short: When i accidentally placed the polarizer back-to-front after a teardown, the display  was inverted. I kept it like that, because it made my calculator look cool... :)
« Last Edit: February 14, 2015, 09:53:14 pm by elgonzo »
 

Offline dannyf

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #6 on: February 14, 2015, 10:04:17 pm »
Quote
Is there a thin polarized sheet in there like I'm assuming?

Yeah. You may need to heat it up, however.
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Offline wraper

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #7 on: February 14, 2015, 11:02:38 pm »
First of all it almost certainly is glued to the glass. Secondly you need to rotate the polarizer by 90o what is impossible because display is not square.

Rotating the polarizer 90 degrees is not necessary. Just flipping it front-to-back should do the trick (assuming there is no glue involved).
When i was a kid i had a calculator whose LCD polarizer and glass were not glued. Long story short: When i accidentally placed the polarizer back-to-front after a teardown, the display  was inverted. I kept it like that, because it made my calculator look cool... :)
That works only for circular polarization AFAIK.
 

Offline SeanB

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Re: dismantling a 16X2 LCD to flip a polarizer? Are zebra strips finicky?
« Reply #8 on: February 15, 2015, 05:10:33 am »
The LCD polarisers are typically placed at a 45 degree angle, so that they can be viewed by people using polarised sunglasses without taking them off. Those are horizontally polarised to reduce glare, the 45 degree angle makes the display still visible, even though it will be low contrast.
 


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