ROYGBIV LED?

[SmurfTacular]

Is there such as a ROYGBIV LED? I know white LED's are basically blue and amber, and there are RGB LED's with Red, Green, and Blue under one dome. But what about Red, Orange, Yellow, Green, Blue, Indigo, and Violet/UV? Do they exist?

 

[HarryN]

Hi, what you are refering to is more or less the modern interpretation of the CRI concept. You are correct that 6 and 9 wavelength concepts are more valuable than simple 3 wavelength approaches.

Are you refering to LEDs which are direct emitters or indirect emitters (phos approach) ?

One of the few companies that actually starts with UV (violet) LEDs to make white is toydo gosei, last time I checked. Most start close to 460nm vs 405nm.

 

[Ken_McE]

Is there such as a ROYGBIV LED?

By their nature, LEDs tend to produce a single, very pure, color. For example, a red LED produces lots of red light, but almost no light of any other color. It's just not able to do it. What you can do is round up a bunch of different emitters, sit them close to one another, and then control them individually to get your desired color.

 

[MikeAusC]

But keep in mind that our eyes, digital cameras and TV sets only have R,G and B sensors/emitters.

 

[yliu]

Correct me if I'm wrong.

I think the Cree MCE RGBW and other similar chips are able to produce the whole visible spectrum.

I dont see the reason of having more colors than RGB.

 

[SemiMan]

But keep in mind that our eyes, digital cameras and TV sets only have R,G and B sensors/emitters.

This comment only "makes sense" in the case of television sets which are direct view. As long as you can individually stimulate each of the eyes "sensors" then with only three colors for a direct view object you can simulate the entire spectrum.

That does not apply to illumination though. For illumination, what you see is a reflection, not a direct view. In this case, "accurate" color representations requires all wavelengths such that the reflected spectrum is representative of the object and allows differentiation.

Semiman

 

[EricB]

Correct me if I'm wrong.

I think the Cree MCE RGBW and other similar chips are able to produce the whole visible spectrum.

I dont see the reason of having more colors than RGB.

To have really saturated colors other than red, green and blue. Like the 590 monochrome amber. You can't get that by mixing red and green. Or if you wanted to have 565 yellow-green and 525 pure green. you can't really get one by mixing the other with red or blue.

I had asked about something lie this before.
The only thing I see as providing hope are the Quantum Dots, of which there are videos of someone instantly changing the wavelength of LED's just by spraying the stuff on. I just wonder if it can be made reversible, and electronically controlled.

The principle here is similar to phosphor, but they produce pure wavelengths (in addition to whites), rather than just altering white through doping.