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These still produce a single [adjustable] wavelength, which means some colors that are displayable on displays of today are not representable using just one of

These still produce a single [adjustable] wavelength, which means some colors that are displayable on displays of today are not representable using just one of these, and multiples will be required.

Scene_Cast2 2y ago
I suppose anything besides the edge of the CIE horseshoe will need multiples.
yig 2y ago
Two adjustable wavelength emitters should be sufficient, right? So the picking-and-placing problem gets easier by factor of 3:2 rather than 3:1.
- modeless 2y ago
  I bet you might run into some interesting problems trying to represent white with two wavelengths. For example, colorblind people (7% of the population) might not perceive your white as white. And I wonder if there is more widespread variation in human eye responses to single wavelengths between primary colors that is not classified as colorblindness but could affect the perception of color balance in a 2-wavelength display.
- mark-r 2y ago
  The whole point of this technology is that you don't need picking-and-placing anymore, it's all built on the same wafer.
mistercow 2y ago
If the refresh rate is high enough, a single LED could flip between multiple wavelengths to dither to non spectral colors.
- layer8 2y ago
  Higher refresh/modulation rates imply higher power consumption. It’s already a trade-off in current display tech for mobile.
  - mistercow 2y ago
    Sure, but that’s assuming you need a higher rate than is already used for brightness. That’s a question I think can only be determined experimentally by putting real human eyes on it, although I think you could do the experiment with traditional RGB LEDs. But the other question is whether the wavelength tuning can be changed at the same rate as intensity.
- MT4K 2y ago
  Or if pixel density is high enough, adjacent pixels could display the colors to combine with no flickering. Unlike regular RGB subpixels, this would only be needed for areas where the color cannot be displayed by an individual pixel alone.
  - mistercow 2y ago
    Yeah, and both techniques can be combined, which common with LCD screens, although it does sometimes lead to visible moving patterns when viewed close up. There’s more flexibility with tunable wavelengths, though, since there will often be multiple solutions for what colors and intensities can be combined to create a particular photoreceptor response. By cycling through different solutions, I wonder if you could disrupt the brain’s ability to spot any patterns, so that it’s just a very faint noise that you mostly filter out.
layer8 2y ago
Yes, it’d be two subpixels instead of the current three. It’s not clear that that’s worth the added complexity of having to control each subpixel across two dimensions (brightness and wavelength) instead of just one (brightness).
- Retr0id 2y ago
  Can you produce "white" with just two wavelengths?
  - deleted 2y ago
    [deleted]
  - layer8 2y ago
    Yes, mix two complementary colors like orange and cyan. You just need two wavelengths that hit all three cone types [0] in the right ratio. There’s the possibility that it’s subject to more variation across individuals though, as not everyone has exactly the same sensitivity curves. [0] https://upload.wikimedia.org/wikipedia/commons/f/f1/1416_Color_Sensitivity.svg https://upload.wikimedia.org/wikipedia/commons/f/f1/1416_Col...
    - exmadscientist 2y ago
      Human vision in the yellow (~590nm) region is known to be extremely sensitive to particular wavelengths. Observe how quickly things go from green through yellow to amber/orange! So this is probably a nonstarter.
      - mark-r 2y ago
        Every single white LED bulb you buy for your light fixtures is a mix of blue LED and yellow phosphor, so in practice it's no problem at all. Although I do concede that the yellow is probably not monochromatic.
        exmadscientist 2y ago

These still produce a single [adjustable] wavelength, which means some colors that are displayable on displays of today are not representable using just one of these, and multiples will be required.

Scene_Cast2 2y ago

I suppose anything besides the edge of the CIE horseshoe will need multiples.

yig 2y ago

Two adjustable wavelength emitters should be sufficient, right? So the picking-and-placing problem gets easier by factor of 3:2 rather than 3:1.

modeless 2y ago
I bet you might run into some interesting problems trying to represent white with two wavelengths. For example, colorblind people (7% of the population) might not perceive your white as white. And I wonder if there is more widespread variation in human eye responses to single wavelengths between primary colors that is not classified as colorblindness but could affect the perception of color balance in a 2-wavelength display.
mark-r 2y ago
The whole point of this technology is that you don't need picking-and-placing anymore, it's all built on the same wafer.

mistercow 2y ago

If the refresh rate is high enough, a single LED could flip between multiple wavelengths to dither to non spectral colors.

layer8 2y ago
Higher refresh/modulation rates imply higher power consumption. It’s already a trade-off in current display tech for mobile.
- mistercow 2y ago
  Sure, but that’s assuming you need a higher rate than is already used for brightness. That’s a question I think can only be determined experimentally by putting real human eyes on it, although I think you could do the experiment with traditional RGB LEDs. But the other question is whether the wavelength tuning can be changed at the same rate as intensity.
MT4K 2y ago
Or if pixel density is high enough, adjacent pixels could display the colors to combine with no flickering. Unlike regular RGB subpixels, this would only be needed for areas where the color cannot be displayed by an individual pixel alone.
- mistercow 2y ago
  Yeah, and both techniques can be combined, which common with LCD screens, although it does sometimes lead to visible moving patterns when viewed close up. There’s more flexibility with tunable wavelengths, though, since there will often be multiple solutions for what colors and intensities can be combined to create a particular photoreceptor response. By cycling through different solutions, I wonder if you could disrupt the brain’s ability to spot any patterns, so that it’s just a very faint noise that you mostly filter out.

layer8 2y ago

Yes, it’d be two subpixels instead of the current three. It’s not clear that that’s worth the added complexity of having to control each subpixel across two dimensions (brightness and wavelength) instead of just one (brightness).

Retr0id 2y ago
Can you produce "white" with just two wavelengths?
- deleted 2y ago
  [deleted]
- layer8 2y ago
  Yes, mix two complementary colors like orange and cyan. You just need two wavelengths that hit all three cone types [0] in the right ratio. There’s the possibility that it’s subject to more variation across individuals though, as not everyone has exactly the same sensitivity curves. [0] https://upload.wikimedia.org/wikipedia/commons/f/f1/1416_Color_Sensitivity.svg https://upload.wikimedia.org/wikipedia/commons/f/f1/1416_Col...
  - exmadscientist 2y ago
    Human vision in the yellow (~590nm) region is known to be extremely sensitive to particular wavelengths. Observe how quickly things go from green through yellow to amber/orange! So this is probably a nonstarter.
    - mark-r 2y ago
      Every single white LED bulb you buy for your light fixtures is a mix of blue LED and yellow phosphor, so in practice it's no problem at all. Although I do concede that the yellow is probably not monochromatic.
      - exmadscientist 2y ago