Konica Minolta Chroma Meter CS-200 - Manual (Page 104)

102
De
scr
ipti
on
Principle of Measurement
Spectral Fitting Method
Konica Minolta’s newly-developed spectral fitting method provides tristimulus values
(XYZ = red, green, blue) with significantly higher accuracy than that of conventional tris-
timulus colorimeters. This is achieved by using the output from 40 sensors to calculate
the spectral response corresponding to human eye sensitivity (CIE 1931 color-matching
functions).
• The CS-200 uses 40 sensors for sensitivity covering the entire visible region and
multiplies each sensor output by appropriate coefficients. This adjusts the spectral
response of the instrument to close to the CIE 1931 color-matching functions.
• In additon to the 2˚ Standard Observer, the 10˚ Standard Observer (for object-color
measurements) can also be selected, which is impossible with conventional tristimu-
lus colorimeters.
Object is measured with this spectral response and gained tristimulus values (X,Y, and Z)
are converted into L
v
xy, L
v
u'v', L
v
T∆uv, and dominant wavelength through calculation to
be displayed as measurement value.
Chromaticity coordinates (x,y) in Lvxy (CIE 1931 color space) can be obtained through
following formula.
X Y
x= , y=
X+Y+Z X+Y+Z
X,Y, and Z are tristimulus values.
380 400 500 600 700 780
1.0
0.5
380 400 500 600 700 780
1.0
0.5
CIE 1931
color-matching functions
Spectral sensitivity of
conventional tristimulus
colorimeters
Relative sensitivity Relative sensitivity
Wavelength (nm)
CIE 1931
color-matching functions
Spectral sensitivity
of the CS-200
Wavelength (nm)
CIE 1931 color-matching functions and spectral response
of the CS-200 CIE 1931 color-matching functions and spectral response
of a conventional tristimulus colorimeter