Quote:
Originally Posted by fjtorres
All true.
But what we're discussing is a color *eink* device, not LCD.
All vendors announcing use of these panels describe them as two-layer, with the top, color, layer used as a color filter. Which *are* transparent or at least translucent.
They also described them as having different resolutions for color and for b&w.
So either two layer eink is real or all the venors are lying...
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All eink is opaque, no matter if a cell is "on" or "off".
The top layer is just a filter. The eink cells are "milky" white liquid with black balls. The cell / pixel is black when the balls are stuck to the front. It's "white" when they are stuck to the back.
So:
1) No transparency as otherwise you'd always see the black balls.
2) The only ways to have colour are
a) A coloured filter. Obviously the underlying eink is 3x resolution in one direction or x2 resolution in both directions.
b) Cells with coloured liquid instead of white. Contrast would be terrible and the resolution in 1/3rd in one direction or 1/2 resolution in both directions compared to a same geometry mono (white only).
c) Coloured balls in the milky white liquid. This has no dark shades unless there are also interspersed normal white & black shades.
The only way to have genuine higher mono resolution (for viewing rather than driving the filter) is an active transparent display of lower resolution that mysteriously works without a colour filter.
ANY colour filter layer on top of any monochrome display reduces the effective visual resolution to that of all the colour elements needed to produce white, so either 1/3rd on one axis, or 1/2 on both axis depending on how the colour is done.
If someone had invented a new display technology, we'd have heard about it ages ago. Some prove to be too expensive or too poor. Mirasol sounded good. Royalties, yield and poor colour compared to hype killed it. One eReader with two brandings for a Chinese and Korean booksellers.
There have been coloured eink for ages using the RGB filters. They need good lighting. I've seen red/black ones but it's not clear how those work. They are sold in small sizes for label applications. Probably labels are Advanced Color ePaper (ACeP) or "E Ink Spectra". I'd be surprised if that can be used to make an ereader.
https://www.eink.com/color-technology.html
Any colour ereader would use "E Ink Triton" (out for ages) or "Print Color ePaper- E Ink Kaleido", both of which are indeed the regular eink with a colour filter, just like LCD.
Poor saturation or else the panel needs too much front lighting. The Kaleido sounds like a printed plastic rather than glass filter but otherwise the same idea as Triton.
Tri= 3, so likely a 3 x 1 colour stripe, thus 300 dpi mono is a 100dpi x 300 dpi for mono or colour.
The "E ink Prism" isn't for displays.