reader and adaptive reading strategy for rf tags

摘要

A disclosed RF tag reader includes a main antenna with directivity covering a first area; a sub antenna with directivity covering a second area that is smaller than the first area; and a switch control unit configured to selectively switch between the main antenna and the sub antenna. In response to receiving an answer signal via the sub antenna from a wireless communications unit moving together with one or more management objects, the switch control unit switches an antenna used for communications from the sub antenna to the main antenna and the RF tag reader performs communications, via the main antenna, with an RF tag each accompanying one of the management objects.