1. Expanded binning options to reduce green/magenta shift
Some of our initial violet chip LED batches had a slightly noticeable green tint. We quickly found the reason was the deviation of Duv value.
Correlated color temperature is one of the most basic properties of a light source that can describe its appearance. We typically refer to a 2700K light source as similar to incandescent, and 5600K as similar to daylight. Generally speaking, the higher the color temperature, the “cooler” or bluer the light looks, and the lower the color temperature, the “warmer” or more orange-yellow the light looks. It is a one-dimensional number that falls on a scale of red-orange-yellow-white-blue-violet.
Chromaticity is often discussed, however, on a two dimensional plane.
Take CCT 5000K as an example. This color temperature is often considered a very neutral, white color. However, not all 5000K correlated color temperature light sources appear the same! 5000K CCT actually is a locus of points that corrrelates to the color temperature of a theoretical black body radiator when heated to 5000K. As we deviate away above the black body line, we begin to see a shift away from this pure white, towards a slight green. Below the black body curve, we see a shift away towards a subtle magenta. This is all while maintaining a correlated color temperature of 5000K. See the diagram below:
Duv measures the derivation from the black body curve. Any value positive (above) shifts towards the green, while any value negative (below) shifts towards magenta.
At present we provide products meeting ANSI standards:
American National Standards Institute (ANSI)
Nominal CCT1) Target CCT and tolerance (K) Target Duv and tolerance
2700 K 2725 ± 145 0.000 ± 0.006
3000 K 3045 ± 175 0.000 ± 0.006
3500 K 3465 ± 245 0.000 ± 0.006
4000 K 3985 ± 275 0.001 ± 0.006
4500 K 4503 ± 243 0.001 ± 0.006
5000 K 5028 ± 283 0.002 ± 0.006
5700 K 5665 ± 355 0.002 ± 0.006
6500 K 6530 ± 510 0.003 ± 0.006
2. Have already developed wider CCT light source.
We focus on developing wide CCT all the time. So far we ensure the extremely high CRI (95+) between 1900K and 5600K, the process is in the test stage, after which the new CCT LEDs will come into the market.
3. Finished the development of bicolor ribbon.
We expect to eradicate the clients’ scruple about choosing the CCT, by placing alternating color temperature LEDs on a single ribbon. Presently we use SMD3528, dimming 3200K to 5600K, CRI 90+, the process is in the test stage as well.
4. Higher power COBs with 95+ CRI
Higher power LEDs using violet diodes with output up to 30W are currently under development.