Note: The screen is an OLED screen. I had assumed it was LCD, therefore the post mentions it as such.
I was disassembling a Samsung phone (GT-I9305) and was able to seperate the LCD into two sections.
The top section consists of the top glass surface and a tinted film wedged between the surface and another piece of glass.
The bottom section includes all the other layers of the LCD with a bronze glass layer on top with a very fine grid like pattern, barely visible to the naked eye. When light it shone on it, a colourful, but distorted reflection is produced. Below this is a black film-like layer with fairly clear and thin light grey horizontal and vertical dashes, similar to those seen in a segmented LCD. Each of the dashes, consistent in size are approximately 1 mm in length.
Based upon this Samsung website, I'm assuming that the layers, from top to bottom are as follows:
- Glass surface - Top chassis
- Tinted film - Top polariser
- Glass layer - Glass substrate
- Bronze layer - Color filter (RGB)
- Black film - Common electrode
I initially thought that the glass surface had an effect on the filtering, so I removed a small section of the tinted film and observed the same effect. If the glass is orientated how it was designed, it filtered, if it was flipped, it wouldn't.
I thought polarisation should work either horizontally or vertically no matter if the film is flipped or not. That's what I've experienced with sunglasses, so, clearly something else is going on.
If the molecules were orientated along the z axis, that would explain how the top section can be rotated without a change to the filtering, but it doesn't explain why it only works in one direction.
So my questions are:
- Have I correctly identified the layers?
- How does the tinted film only filter in one direction?
- What is the name of this effect?