An interchip for implantation into a gaming chip or token provides a circular array of light-receiving faces arrayed about the circumference of the chip or token. Light received by one face is conducted to the remainder of the faces by a number of internal fingers which communicate light to and from...http://www.google.com/patents/US5361885?utm_source=gb-gplus-sharePatent US5361885 - Anticounterfeiting device for gaming chips
