Atec Konica-Minolta-CL-200A - Manual (Page 5)

When made from blue LED and phosphor
The blue light emitted by the LED mixes with the yellow light
emitted by the phosphor to create white light.
Problem:
Since the spectral emission distribution of the
blue light emitted by the LED varies for each unit,
variations in the resulting white light will occur. Since
usually LED lamps use several LEDs, control of
color mixing is necessary.
General solution:
➀ Measure the spectral emission
characteristics of each LED element
and rank them accordingly.
➁ Measure the emission characteristics of the
phosphor and rank accordingly.
➂ Combine the ranked LED elements and ranked
phosphor materials to achieve the desired white
light.
➃ Inspect the output light quality of the final assembled white LED lamp.
How the CL-200A can help:
The CL-200A can measure the chromaticity from the phosphor and also
inspect the output light quality of the final assembled white LED lamp.
LED total flux measurement system
❚ This system combines our top-of-the-line Spectroradiometer CS-2000 modified for illuminance measurement with an LED
total flux measurement adapter to create an LED measurement system that utilizes a spectral measuring instrument
conforming to CIE 122-1996 as the receptor. The total flux emitted in all directions by the LED is diffused by the integrating
sphere and received for measurement by the spectroradiometer.
❚ This system conforms to CIE 127:2007.
❚ Since the spectral response of the receptor matches the CIE spectral luminous efficiency function V( λ ), there is no need to
perform troublesome color correction.
❚ To enable accurate measurements, a self-absorption compensation function is provided to compensate for the reduction
in integrating sphere output due to self absorption of the light source when it is lit inside the integrating sphere.
General Reference Information
Measurements in the LED manufacturing process
LED Total Flux Measurement System
PC
Baffle
LED
LED holder
Integrating
sphere unit
Self-absorption
compensation LED
Constant-current
power supply
Spectroradiometer CS-2000
(modified for luminance measurement)
LED measurement
software
Cross-section A Illuminance (lx)
Horizontal distance (m)
H
ei
gh
t (
m
)
0
0
1
1
2
2
3
3
4
-1 -2 -3
300
100
50
10
30
5
Colors mix to create white light!
Blue light emitted by LED element
Yellow light emitted by phosphor
Package
Electrode
Wavelength (nm)
LED element
Phosphor
Wavelength (nm)
Variations in white light