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Is there a such thing as a transparent electronic paper display that is commercially available ?

I've found that Samsung has a transparent LCD, but I haven't been able to find any examples of transparent e-paper.

Walter Stabosz
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    I don't think you're going to find such a thing. All of the e-paper technologies I'm aware of intentionally use *opaque* white/black particles to produce their images. They're implicitly reflective, not transmissive, displays. – Dave Tweed Oct 08 '12 at 21:46

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Not likely. E-ink consists of an array of tiny balls between two two electrode sheets.

enter image description here

source

A positive or negative electric field makes that either black or white pigment chips will be at the viewing side. If those were transparent you would see the inactive white chips through the black ones and vice versa, and have no contrast.

There's an illuminated Kindle, the Paperwhite, but that has front-lighting, not back-lighting:

enter image description here

source

Walter Stabosz
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stevenvh
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    wow ! Need to give +100 for info. – Standard Sandun Oct 09 '12 at 12:53
  • What if instead of using the titanium dioxide particles (the white pigment), glass was used. Would that make the displays transparent ? I suppose the bottom electrode would have to be made transparent also. – Walter Stabosz Oct 09 '12 at 13:38
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    @Walter - No that wouldn't work. If you would look through a black pixels and its inverse below you would see the same as looking through a white pixel and its inverse below; there won't be any difference between black and white. The pigment chips have to be opaque to prevent you from seeing the inverse color underneath it. Also, if you would see what's behind the display, how can you see the display itself? Head-up displays works because their image is projected on *the front* of the glass. The projector needs a high light level and high contrast. – stevenvh Oct 09 '12 at 13:50
  • @stevenvh great point. I think this completes my understanding of why e-paper displays are all front-lit. – Walter Stabosz Oct 09 '12 at 17:13
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    The question asked about e-paper, not e-ink. Epaper displays use a wide range of technology. E-ink is a single trademarked technology. – MattCochrane Nov 08 '15 at 00:52
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Yes, displays based on PDLC have been developed for reflective/transparent mode operation. For this to work, your pixel layer has to achieve a nice diffuse state (traditional LCD does not).

Jason Heikenfeld
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  • From my understanding, require a constant voltage to remain in the transparent state (and is opaque with no voltage). e-paper only requires voltage to switch states, but not to remain in a given state. – Walter Stabosz Oct 09 '12 at 17:10
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    @Jason - Walter asked specifically about e-paper/e-ink. PDLC is an LCD technology. – stevenvh Oct 09 '12 at 17:29
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Cholesteric Lcd can be the option, it's optical perneteation >25% http://www.iris-opt.com/index.php?lang=en

user321335
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