| abstract |
PCT No. PCT/GB95/01036 Sec. 371 Date Nov. 8, 1996 Sec. 102(e) Date Nov. 8, 1996 PCT Filed May 9, 1995 PCT Pub. No. WO95/30972 PCT Pub. Date Nov. 16, 1995Apparatus for distinguishing between genuine and counterfeit articles whereby a first optical filter is applied to genuine articles and suspect articles are scanned with the aid of a suitable second optical filter. Scanning of genuine articles incorporating first optical filter with the aid of suitable second optical filter gives rise to optical effects which would not otherwise be apparent. |