4 ms·
Probably because one of those two facts: 1. The blue light is physically behind the others wavelength; 2. The blue is (much) more intense than other wavelengt
by bXVsbGVy 4y ago
Probably because one of those two facts:
1. The blue light is physically behind the others wavelength;
2. The blue is (much) more intense than other wavelengths.
Some background.
The LCD panel is a RGB filter in front of a white light.
White light is usually* made with a blue diode with some phosphor on top. The phosphor converts some (but not much) of the blue light into the rest of visible spectrum. Most of emitted light is the original blue from the diode.
Fun fact: The sun is also mostly blue. And there are white lights that are pretty much only blue, but we perceive as white (usually sold for vegetative growth of plants).
* In the past we used fluorescent tube. Quantum dot film are becoming common now (they have been used for a while, but are mainstream now because Rec. 2020). There are white diodes, but I haven't heard about them being used as backlight -- their CRI are pretty terrible, and they are expensive.
- grkvlt 4y ago> Quantum dot film are becoming common now (they have been used for a while, but are mainstream now because Rec. 2020) not really, there are essentially zero quantum dot based white light products commercially available right now, apart from some very niche offerings that are expensive and unreliable like osram/plt leds. and what does 'because Rec. 2020' even mean as a justification?
- bXVsbGVy 4y agoI'm talking about QD films, not diodes. Since early 2010s Vizio, HiSense and TCL made TV with 3M's QDEF [1]. This year, a few brands made TVs with perovskite quantum dot film. They are being branded as QLED. The widespread adoption of Rec. 2020 creates a demand for displays capable of displaying larger color volume. Phosphor LEDs TVs have around 60% coverage of Rec. 2020. The best OLED TV has 73% coverage. QDEF TVs has up to 81% coverage. The perovskite quantum are capable of achieving more than 90% (but the commercially available TVs are not there yet). [1] https://multimedia.3m.com/mws/media/985375O/3mtm-quantum-dot-enhancement-film-qdef-white-paper.pdf https://multimedia.3m.com/mws/media/985375O/3mtm-quantum-dot...
- grkvlt 4y agook, so in TVs? makes more sense, thanks! also i learned about https://en.wikipedia.org/wiki/Rec._2020 https://en.wikipedia.org/wiki/Rec._2020 today...
- bXVsbGVy 4y ago> ok, so in TVs No idea why there isn't any computer display with QDEF. It is probably easy to convert them using a filter from a old TV. However, But, this is probably not a good idea, those old quantum dots were toxic. I think QLED will be everywhere.