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Stretching Crystals Promise Bendy, Full-Color Displays

NewScientist is reporting that a new approach to crystal formation could help create power-efficient, flexible color displays. These new photonic crystals, structured similar to opals, can be tuned by adjusting the gaps between the crystals. "The beauty of the device is that it can produce the whole spectrum of colors, even ultraviolet and infrared light, using only incident light. As a result, the expensive color filters used in every other color display on the market today, are no longer needed. And because the displays use only reflected ambient light, no power is wasted on back-lighting, as in today's mobile phones, for example. 'They can be viewed just as well in bright sunlight as in indoor light,' team member André Arsenault of the University of Toronto told New Scientist."

15 of 117 comments (clear)

  1. Uhh... by SighKoPath · · Score: 4, Funny

    They can be viewed just as well in bright sunlight as in indoor light
    What about in complete darkness? Gotta keep the basement-dwellers happy...
    1. Re:Uhh... by maino82 · · Score: 3, Interesting

      This is a very good point and I think it would be interesting if you integrate a photocell into the devices. When the photocell detects enough ambient light, you can turn the backlight off, but when there is no light, or very low light, you turn the backlight on, or possibly even dim it up and down. This way it can function in varying degrees of ambient light, but can also save a significant amount of energy.

    2. Re:Uhh... by timeOday · · Score: 4, Insightful
      That's why these paper "books" will never catch on. No backlighting!

      From the blurb, this sounds like the holy grail: reflective, full color gamut, and flexible to boot. Of course we all know what happens to 99% of breakthrough technologies that should be ready for the market in 2-4 years...

    3. Re:Uhh... by kebes · · Score: 3, Interesting

      I'm not sure that backlighting will work - since this is a reflective technology.
      It is indeed a reflective technology... but the non-reflective state is transparent rather than black (in the scientific paper they actual show an image in the off/transparent state). The most obvious way to use such a technology is against a black backing. In the 'off' state the entire display looks black, but you can then adjust pixels to be any bright color you want. By mixing the state of adjacent pixels you can presumably get a white color, or anything else.

      However the reflection effectively acts like an absorption if viewed transmissively. So if you had a backlight, you could tune the effective absorption band of each individual pixel. By cutting out a band of colors (and using adjacent pixels), you effectively have full color control.

      So it's possible to imagine a future version of this tech where the display is normally reflective (black backing) but when required switches to emissive display (which would require a backlight turning on, and inverting the logic of the display pixels so that the colors don't come out inverted). Thus you'd have the "best of both worlds."
  2. 1000 words by Verteiron · · Score: 3, Informative

    This story is worthless without pictures.

    There are none here, although there's no shortage of sales brochure style summaries:
    http://www.opalux.com/technologies.php

    --
    End of lesson. You may press the button.
  3. Re:Ha! by Ed+Avis · · Score: 4, Insightful

    The article says that if you can produce light of any frequency you don't need colour filters. But this can't be the case, because a computer display needs to mix different frequencies (to produce white light, for example). That said, if they can control the proportion of incident white light that is reflected as white rather than coloured to a single frequency (or narrow band of frequencies), and with a simple light/dark filter (such as a black and white liquid crystal display), it could make a display that works on hue-saturation-value rather than red-green-blue. That would be interesting for the computer world, which has used boring RGB values to store image data for so long. I know that JPEG stores chrominance and luminance separately but I'm not aware of any file format (let alone graphics hardware) which works using HSV.

    (BTW, does anyone know how to post a comment to an article using the new discussion system?)

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    -- Ed Avis ed@membled.com
  4. Sunblock required for computer users by LurkerXXX · · Score: 4, Funny

    "The beauty of the device is that it can produce the whole spectrum of colors, even ultraviolet and infrared light"

    Sweet, now we can get a virus on our computers that gives us sunburn.

    I wonder if Hawaiian Tropic will hire me as a blackhat to ensure they get increased sales from computer users. Maybe they'll introduce me to the girls.

  5. Re:Ha! by somersault · · Score: 4, Insightful

    Presumably the only reason that we have to use pixels, are because we didn't have any material (or any cost effective method of manipulating a meterial) that could produce colours of any desired frequency (until now). So they just used single coloured phosphors that could be adjusted to different brightnesses of a single colour, and when mixed with 2 other colours, can fool the eye into seeing any colour. If you can just set the colour directly, why bother using 3 separate colours to fake it instead.

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    which is totally what she said
  6. Re:hmm "infrared light based laptops!" by somersault · · Score: 3, Insightful

    Might be better just to use bluetooth or a short cabled connection to hook into the goggles.. unless night vision can amplify the screen in enough detail when it's getting so little ambient light on it.

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    which is totally what she said
  7. Great, but now... by Overzeetop · · Score: 3, Insightful

    ...we all need to have calibrated room lighting in order to get the proper colors to show up. No blue with that 60w incandescent!

    Which brings me to...how does this work with fluorescent lighting? If you're using partial reflectivity, human eyes get the proper fractions of the constituents of the phosphors. If you're using interferometry, wouldn't you end up with huge dropouts in the visible spectrum?

    --
    Is it just my observation, or are there way too many stupid people in the world?
  8. Re:As usual by Henneshoe · · Score: 5, Insightful

    I see you have a +5 insightful, so this is for you and everyone who agrees with you. Get out of the /. science section if you do not want to hear about this stuff till it hits market. Two years from now if this display is good enough to be sold, you can read about it in /. hardware. Many of us enjoy hearing of new discoveries even if they may never make it to market.

  9. Re:Ha! by kebes · · Score: 3, Insightful

    These photonic crystals are being built into arrays of pixels, where each pixel can, effectively, control its reflection color. So, a pixel can set itself to 'black' by adjusting its reflection to be outside the visible range (in the IR or UV), or can set itself to 'red' by tuning itself to have a reflection in the red region of the spectrum. So each pixel can take on a continum of color values:

    (Black), Red, Orange, Yellow, Green, Blue, Indigo, Violet, (Black)

    To generate a white reflection (or non-spectral colors, like brown), adjacent pixels would still have to do what we do in modern displays: one would be Red, the other Blue, the other Green, and your eye would see reflected white light. So in a certain sense it has the same pixel-clustering limitation of current displays.

    However it's better than current displays in some ways. First of all, if your image happens to be monochromatic (or parts of the display are monochromatic) then you don't have to be using three display pixels for a single image pixel... so in essence you can triple your display resolution. No doubt if such displays become common, algorithms will be developed that allow the display to maximize resolution when possible.

    Perhaps more importantly, however, is that the color range is greater. A typical display mixes Red, Green and Blue. But the wavelength of the Red, Green, and Blue that are available are inherently limited. This means that although the display can generate many colors, it doesn't actually cover the full color range of colors that your eye can see. With this proposed display, you can adjust the Red, Green, and Blue wavelengths themselves. This provides access to a wider color range. For instance, when this display sets itself to 'orange' it will be a pure spectral orange, rather than an approximation generated by mixing the right amount of red, green, and blue.

    And, of course, an obvious advantage is that this system is reflection-mode. Like paper, it doesn't generate light, merely reflects ambient light. This makes it ideal for reading outdoors, in natural light, etc.

  10. Is this the last we'll hear of it??? by Twinbee · · Score: 4, Insightful

    Is there anyone, anywhere on the web who ever tracks these technologies that are supposed to 'make it to the market soon'? I mean how about it. A site that finds out whether these new techs die, simmer down, or flourish.

    There are a billion and one news sites out there, each reporting thousands of 'just in' stories each day. To have just one that actually tracks the progress of each technology would be amazing. Give each tech their own special page, and then add to them as further news comes in about the SAME tech. Perhaps add a progress bar in the form of a percentage of expected market release too. Pretty please? I'm just getting sick and tired of hearing about these amazing new futuristic gadgets, and then never hearing about them again.

    --
    Why OpalCalc is the best Windows calc
  11. Re:Ha! by Cryolithic · · Score: 5, Funny

    Doesn't use of IE6 lead to automatic revocation of Slashdot privileges? Just sayin'...

  12. Re:Ha! by TheRaven64 · · Score: 3, Informative
    It's worth pointing out that RGB is an artefact of our retina, not our display technology. We have three different kinds of wavelength-specific sensors in our eyes which detect three fixed wavelengths (with some leakage to the sides). This is entirely a human thing; it is conceivable that a creature with a different evolutionary heritage might only have two wavelength sensors, or more than two.

    To accurately represent any given colour, you need an infinite number of values, not just three, since a colour is the sum of an arbitrary number of wavelengths of light. The red cones in our eyes, for example, detect light at around 580nm. If a photon with a wavelength of 590nm hits the red cone, then it is perceived as being a slightly weaker 580nm signal, rather than a different colour. This lets us fool our eyes into thinking they are seeing the full range of colours when they are only seeing three in a different wavelengths with different amplitudes. A species which saw colours properly would find it much harder to design a colour display.

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    I am TheRaven on Soylent News