CIE chromaticity diagram.All possible
color coordinates(x,y)are on or indide the horseshoe curve.Pure
colors lie on the curve, whereas the white point has the coordinates(1/3,1/3)
Luminous flux, :
Unit:lumen, lm
Amount of radius energy visible to the human eye emitted by
the light source.
Color Temperature:
Unit:absolute temperature (Kelvin, K)
The Color Temperature of a light source is defined as the
absolute temperature of the standard “black body radiator”
that emitting the light of the same color; a corresponding
point can be plotted on the Plank Spectrum of color intensity.
Higher than the temperature on the standard black body, the
light it radiates has more blue content and less red content.
Take the common soft white incandescent lamp as an example,
the color temperature is 2700K;while that of the daylight
fluorescent lamp is 6000K,
Light color:
The “Light Color” of a lamp
can be categorized by its color temperature.
Three major “Light Colors” are:
Warm color: <3300K
Medium color: 3300 to 5000K
Daylight color: >5000K
Even having the same Light Color, different lamps very in
color rendering because they emit the light with a different
spectrum composition.
Spectrum:
The set of light waves are distributed
according to the order of wavelengths.Each light source has
a Power Spectrum Distribution in the Light Spectrum.Power
Spectrum Distribution of the sun or an incandescent lamp is
a continuous curve, while that of a common electric-discharge
lamp is not a
continuous curve.
Light Emitting Diode(LED):
LED is a p-n diode made of specific materials.
Under a positive bias,the electrons flow across the joint
face, in the process of re-joining and disappearing, they
emit light. Small in volume and low in Luminous efficacy,
yet in the recent years LEDs developed rapidly and the application
is setting
foot in the fields of traffic light, indicators, and even
lighting of some special occasions. |
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