Patent ID: 9748636
Date: 2017-08-29
CPC Classifications: H01Q,H04M

Claim:
1. An antenna device incorporated into an electronic apparatus and configured to communicate with an external device via an electromagnetic field signal, the antenna device comprising: a first electric conductor provided inside a casing of the electronic apparatus and facing the external device; an antenna coil provided inside the casing of the electronic apparatus and inductively coupled to the external device; and a second electric conductor in sheet form, the second electric conductor being provided inside the casing of the electronic apparatus, overlapping or being in contact with the first electric conductor, and at least partially overlapping a surface of the antenna coil, the surface being opposite to a surface facing the external device, and the first electric conductor overlapping the surface of the antenna coil, wherein the second electric conductor overlaps one side of the antenna coil, the one side having a lead wire wound around thereon in one direction, and does not overlap another side of the antenna coil, the another side having the lead wire wound around thereon in another direction, and wherein the number of turns of the antenna coil on the one side overlapped by the second electric conductor is smaller than the number of turns of the antenna coil on the another side not overlapped by the second electric conductor.