WCA November 2012

for an automatic device as well as for a line operator. So this is not a problem in colour measurement itself but a possible improvement of quality control by a simple redefinition of colour pairs with high ∆ E.

References

[1] [2]

Edward H Adelson, MIT, 1995

https://www.ral-farben.de/492.html?&L=1

[3] Joint ISO/CIE Standard: CIE Colorimetry – Part 1-5, ISO 11664-1··5/ CIE S014-1··5/E:2006-2007 [4] Masataka Okabe, Kei Ito (2008-02-15). Color blind barrier free. http:// jfly.iam.u-tokyo.ac.jp/color/

reference can be stored for further production of this wire type. Any number of recipes can be stored. Until now the recipe database is very simple and should include search functions in future software. Connection to the line PLC should be possible via simple digital 24V signals (signal status and device enable) where fault messages are implemented to the coil protocol like spark or diameter faults or with a more complex network communication via TCP/IP to have access to the recipe database or to support host computer link. Figure 9 shows the main screen that includes the most important information for the line operator. Additional windows can display more details, like separated L*/a*/b*-channel measurement, various signal history or trend information. For later evaluation, a subsample of raw data is stored on the IPC hard disk. To be independent of all production lighting conditions, the scan field is covered and illumination is done by an internal LED light source (see Figure 10, white arrow). According the higher luminance variation compared to a* and b*, a modification of equation (1) should be tested: ❍ ❍ Figure 10 : Prototype of Siebe colour measurement system during test at a customer’s line. Installation between spark test and lump camera. IPC at the top, below, turn mechanics and sensor (under light cover) While equation (1) represents a circular error distribution, the modification is an elliptical distribution with enhanced tolerance in the L* channel (for f > 1). Technical aspects are almost solved; the main focus is now the improvement of device interface and handling. This needs feedback from the wire and cable production companies. Another point of discussion should be the combination of stripe and main colour. For example main colour red with a brown stripe is difficult to separate

eq (2)

Siebe Engineering GmbH Industriegebiet Fernthal 53577 Neustadt/Wied, Germany Email : vkde@siebe.de Website :www.siebe.de

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