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Comment by manwe150 | Hacker News Reader

I don’t know the answer, but I think there is usually 2 green subpixels, so 1+1+1+4 to 1+1+1+1 for that facet

You’re thinking of the Bayer pattern for sensors, which have four equal RGGB squares. When an RGGB pattern is used for displays, the more numerous green subpixels need to be smaller to maintain the correct white balance, resulting in the same 1+1+4 power profile.

Yes, for cameras it is called Bayer. For displays Samsung coined Pentile. It is by far the most common array of mobile OLED subpixel designs (RGGB), used in mobile devices (eg iPhone, Galaxy, Pixel, Huawei, Oppo, Xiaomi).

GP's point was that it's not the number of pixels, but the power draw that matters here (for power consumption) and while there are more greens they are smaller and draw less.

This design pattern happens because humans are more sensitive to greens, but that doesn't mean you need more green output.

Exactly, for a white balanced screen you need the same number of photons whether they are at a higher resolution (like Pentile) or not. Adding a White (or Yellow or Cyan) subpixel for RGBW can improve efficiency for the less saturated part of the color gamut, but obviously not the pure red green or blue colors.

If I understand correctly you don't want the same number of photons. You need more blue photons.

I'm saying photons here, because there are so many words that have very specific meanings that are not typically understood (Nits, Candela, Lumens, Luminance, Brightness, Illuminance, Luminous Flux (Lux), and Luminous intensity) by the lay person. However, just looking at the 5500K black body the power density of any Blue is well below that of any Green or Red, and since the energy per photon is higher at shorter wavelengths (blue) that means the photon flux is significantly lower (about half the number of photons/sec/m2 of green).

http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/coltemp.ht...

Just for the plot.

The reason that Cyan (between Blue&Green) and Yellow (between Red&Green) subpixels added to the full pixel can be more efficient for white (or unsaturated colors) is that they are detected better by the eye (perceived brightness) for an amount of power or photons than a primary Blue or Red.

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