| US 7,515,925 B2 | ||
| Wireless communication device for periodically controlling a carrier wave to establish a good communication state with a communication object | ||
| Atsushi Nakagawa, Kawasaki (Japan) | ||
| Assigned to Kabushiki Kaisha Toshiba, Tokyo (Japan) | ||
| Filed on Dec. 29, 2004, as Appl. No. 11/23,512. | ||
| Claims priority of application No. 2004-026619 (JP), filed on Feb. 03, 2004. | ||
| Prior Publication US 2005/0170793 A1, Aug. 04, 2005 | ||
| Int. Cl. H04B 7/00 (2006.01) | ||
| U.S. Cl. 455—522 [455/127.1; 455/41.2; 235/472.02; 235/380; 235/492; 340/10.1; 340/572.1] | 8 Claims |
| 1. A wireless communication device comprising:
an antenna configured to carry out a wireless communication with a communication object;
a carrier wave transmitting unit configured to transmit via the antenna a carrier wave to the communication object located
in a communication ready area from the antenna as a base point, the carrier wave having a level exceeding a threshold level
that can render the communication object to generate electric power for the communication;
a carrier wave control unit configured to periodically set the level of the carrier wave transmitted from the carrier wave
transmitting unit temporarily lower than the threshold level; and
a signal receiving unit configured to receive via the antenna a response signal transmitted in reply to the carrier wave from
the communication object in the communication ready area,
wherein the carrier wave control unit temporarily sets the carrier wave to a level lower than the threshold level when the
signal receiving unit does not receive the response signal within a certain period of time after the carrier wave transmitting
unit transmits the carrier wave.
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