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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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