What type of plastic is the top layer of an LCD display made of?

[Herbert]

Dear all,
I am not referring to the decorative glass on a watch or a front panel, but rather the top layer of a liquid crystal display, in my case a simple grey one with black digits.
The background to my question: the decorative glass on my Discman has been lost. When cleaning the exposed LCD display, even a cotton bud can cause fine scratches. So it's not possible to polish it like you would with acrylic. But I could try covering the surface with a specially cut protective glass for mobile phone displays. Ideally, of course, the adhesive would be crystal clear and level out the scratches. For the glue, I would need to know what kind of foil (probably a polarizing filter) is or was typically used, as the Discman is now 35 years old. Is it acetate film? I believe that if there is a forum where people might know the answer, it would be audiosciencereview...
Best, Herbert

 

[JeffS7444]

I don't know that the specific sort of material is always the same, or whether it's particularly critical. Top layer is typically a polarizer, followed by the glass LCD sandwich itself, followed by another polarizer, and finally, a reflective background. Usually, but not always, the layers are bonded together.

The LCD itself is very reliable, but the polarizers and reflective background sometimes degrade over time.

Tempered glass typically can't be cut without shattering, but I dunno about Gorilla Glass.

 

[bmc0]

This is just based on a few quick internet searches, so interpret with some caution/skepticism. Linear absorptive polarizing film is typically made of stretched polyvinyl alcohol doped with iodine, which, as far as I can tell, is usually (always?) laminated between two protective layers in addition to the outer glass/etc. layer. The most commonly mentioned protective film seems to be cellulose triacetate, but I also saw polyolefin listed.

So, my guess is that the surface you're talking about may be cellulose triacetate, but I don't really know what I'm talking about so I'm not that confident .

 

[somebodyelse]

Tempered glass typically can't be cut without shattering, but I dunno about Gorilla Glass.

Gorilla Glass is cut with a variety of industrial methods. I guess the most likely to work at home would be a diamond coated blade for a Dremel with a bit of water.

I'd probably try phone screen protectors or self-healing plastic films like helicopter tape or the InvisibleShield phone wraps. I've never tried cutting phone screen protectors.

 

[mhardy6647]

helicopter tape?
The mind boggles -- gotta look into this!

 

[JSmith]

the decorative glass on my Discman

No Sony Discman models ever used real glass over the LCD display... they all used plastic (polycarbonate) windows.

Might be easier to find a broken one on eBay cheap for parts.


JSmith

 

[Herbert]

Thanks for the answers!„Decorative glass“ is just a term, I know that the window is polycarbonate, mine warped and came off in the sun. But this thread is not about the window of the Discman, a D-J50. Very rare and overpriced btw. I bought mine in 1992 and haven’t used it for about two decades. In fact, when the problem with protecting the LCD with a thin layer of glass and thereby getting rid of the scratches is solved, I will cut a decorative window. There is a special acrylic glass that is scratch resistant, I guess the same coating as with Blu Rays.

So, the last word is cellulose triacetate or polyolefin...?