Loop antenna and contactless IC card read/write apparatus

A loop antenna having an electromagnetic wave shield over at least one side of the loop antenna, the electromagnetic wave shield comprising:

• a plurality of electric conductors;
• a ground contact, grounding the plurality of electric conductors;
• and
• a lead wire, connecting the plurality of electric conductors to the ground contact, wherein:
• the plurality of electric conductors are electrically connected via the lead wire to the ground contact and arranged so that the paths of the respective electric conductors from any of their given points to the ground contact via the lead wire are determined uniformly,
• a sheet of magnetic material is disposed at the back of the loop antenna facing the electromagnetic wave shield, and
• a side wall in a standing condition on the loop antenna side is provided to the sheet of magnetic material.

A contactless IC card read/write apparatus comprising a loop antenna, having an electromagnetic wave shield over at least one side of the loop antenna, for supplying electric power and transmitting data to a contactless IC card by electromagnetic induction and receiving data from the contactless IC card through load changes and a read/write apparatus connected to the loop antenna, the electromagnetic wave shield comprising:

• a plurality of electric conductors;
• a ground contact, grounding the plurality of electric conductors;
• and
• a lead wire, connecting the plurality of electric conductors to the ground contact;
• wherein:
• the plurality of electric conductors are electrically connected via the lead wire to the ground contact and arranged so that the paths of the respective electric conductors from any of their given points to the ground contact via the lead wire are determined uniformly, and
• the read/write apparatus is disposed within the opening of the loop antenna and housed in a casing.