Table 1: Dominant wavelength
components [nm] occurring in the considered ranges.
The proposed white-light LEDs were fabricated with CIE chromaticity coordinates (x, y) of (0.349, 0.393) and correlated color temperature of 4991K with a dominant wavelength
of 564 nm.
The dependence of the measured illuminance attenuation coefficient on LED colour (dominant wavelength
) is presented in Table 2 and Fig.
Specifically it would be that the dominant wavelength
is perceived as the color under certain defined conditions of viewing.
We selected these two because the former (Y, [H.sup.*] = 226[degrees], associated dominant wavelength
575 nm) produces the BB effect when changing stimulus luminance whereas the latter (B, [H.sup.*] = 577[degrees], associated dominant wavelength
485 nm) does not.
That the reverse were true for the other categories implicitly indicates the existence of important B-B effects, because it shows that for the same dominant wavelength
stimuli different basic categories were used in response to different lightness.
Optical measurements able to be taken by the device include total radiant and luminous flux, peak wavelength, dominant wavelength
, CIE purity and CIE chromacity.
Shifted dominant wavelength
. Dominant wavelengths
shift by about 2 nm for every 10[degrees]C change in junction temperature.
Correctly would be that certain stimulus's (dominant wavelength
) under certain defined conditions are perceived as their colour.
Designed with a 140-degree viewing angle and a dominant wavelength
of 647 nm, this miniature surface-mount BR111C LED can be used for a wide range of electronic devices.
The analysis of the relationship of the NCS with the colourimetric parameters showed that every NCS hue was associated with a specific chromatic angle and with one dominant wavelength
. The relationships between NCS whiteness and CIE lightness, on the one hand, and between CIE and NCS chroma parameters, on the other, were high but not so closed.
In order to improve the situation, NIST has investigated the technical problems and is developing standard LEDs and recommended measurement methods for luminous intensity, total luminous flux, and color (chromaticity and dominant wavelength