A finger ring is provided with an information storage unit (21) and at least two electrically conductive, mutually insulated ring elements that serve as contacts(1). To enable quick and reliable mating of the contacts (1) of the ring with corresponding mating contacts (17) of a control device, the ring...http://www.google.com.hk/patents/US6020826?utm_source=gb-gplus-share專利 US6020826 - Finger ring with information storage unit
