A design of scanning mode coated glass color difference online detection system was introduced. The system
consisted of color difference data acquirement part and orbit control part. The function of the color difference data
acquirement part was to acquire glass spectral reflectance and then processed them to get the color difference value.
Using fiber for light guiding, the reflected light from surface of glass was transmitted into light division part, and the
dispersive light was imaged on linear CCD, and then the output signals from the CCD was sampled pixel by pixel, and
the spectral reflectance of coated glass was obtained finally. Then, the acquired spectral reflectance signals was sent to
industrial personal computer through USB interface, using standard color space and color difference formula nominated
by International Commission on Illumination (CIE) in 1976 to process these signals, and the reflected color parameter
and color difference of coated glass was gained in the end.
The function of the orbit control part was to move the detection probe by way of transverse scanning mode above
the glass strip, and control the measuring start-stop time of the color difference data acquirement part at the same time.
The color difference data acquirement part of the system was put on the orbit which is after annealing area in coated
glass production line, and the protected fiber probe was placed on slide of the orbit. Using single chip microcomputer to
control transmission mechanism of the slide, which made the slide move by way of transverse scanning mode on the
glass strip, meanwhile, the color difference data acquirement part of the system was also controlled by the single chip
microcomputer, and it made the acquirement part measure color difference data when the probe reached the needed
working speed and required place on the glass strip.
The scanning mode coated glass color difference online detection system can measure color parameter and color
difference of each transverse point on glass strip, it can also measure lengthways color stability on glass strip.
Furthermore, the measuring results can be transmitted to coated control room through intranet, so it is very useful to
improve producing technique in time. In addition, equipping necessary marking machine, this system can classify glass
board automatically based on the measuring result.