Patent ID: 7557713

Claim:
A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising: a frame; a conveyor that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon; a plurality of antennas disposed proximate the path of travel so that the antennas radiate radio frequency signals into a first area through which the items pass and receive responses to the radio frequency signals from the respective radio frequency identification tags on the items in the path of travel, wherein at least one of the plurality of antennas is disposed so that the items pass through the path of travel between the conveyor and the at least one of the plurality of antennas; at least one radio frequency transmitter that drives the antennas to emit the radio frequency signals into the first area; at least one radio frequency receiver that receives signals from the antennas corresponding to the responses received by the antennas from the respective radio frequency identification tags and outputs first signals corresponding to the responses; a detector disposed with respect to the path of travel so that second signals output by the detector indicate a height of items passing proximate the detector through the path of travel, and a processor that receives the first signals from the at least one receiver, wherein the processor is programmed to control the at least one transmitter to drive said antennas in a predetermined sequence with respect to each other, associate a said first signal with a first said item based upon whether the processor receives the first signal from the at least one receiver while at least a portion of the first item is within a second area that includes at least part of the first area, and based on the second signals, eliminate the at least one of the plurality of antennas from the predetermined sequence when the first item is within the second area if the height of the first item is below a predetermined threshold.