Patent ID: 7617987

Claim:
A reader/writer apparatus for communicating with an IC chip of an object to be identified, the reader/writer apparatus including a loop antenna for communicating contactlessly by electromagnetic induction with the IC chip and transmitting electric power to drive the IC chip, wherein: the loop antenna comprises a lead wire formed into a plurality of linked antenna elements of identical or substantially identical shape, the loop antenna is provided on a rectangular planar member, and the plurality of antenna elements are linked in a longitudinal direction of the rectangular planar member; the plurality of antenna elements are linked in one direction; the lead wire of the loop antenna crosses over itself at intersection points between adjacent antenna elements; each of the antenna elements is constituted by a combination of wire portions, and all of the wire portions forming the antenna elements are nonparallel to the linkage direction of the plurality of antenna elements; and the adjacent antenna elements are asymmetrical to each other relative to the respective intersection point.