| 摘要 |
PCT No. PCT/SE93/00038 Sec. 371 Date Sep. 6, 1994 Sec. 102(e) Date Sep. 6, 1994 PCT Filed Jan. 20, 1993 PCT Pub. No. WO93/14474 PCT Pub. Date Jul. 22, 1993Electronic identification device includes a circuitry (10) for generating and emitting an electromagnetic field and a plurality of transponder units (11). Each of the transponder unit includes a storing circuitry (12) for storing identification data, and a transmitting circuitry (13) for transmitting a signal including the identification data when the transponder unit (11) has been exposed to the electromagnetic field. The electronic identification device further includes a receiving circuitry (14) for receiving the signal and for decoding the identification data. At least one element (15) of a material, having the magnetic or electrical properties being influenced by external magnetic fields, is disposed on or in the absolute vicinity of the transponder unit (11), and a magnetic field generating circuitry (16) for generating a magnetic field is provided at an interrogation zone (17) to activate any element (15) appearing in the interrogation zone (17). A processing circuitry (18) is provided in the transponder unit (11) to modify the signal in dependence of the magnetic field activating the element (15). |
