Patent ID: 7828211

Claim:
A system, comprising: a first set of items positioned in a first item zone, each item in the first set of items having a machine-readable identification tag; an electronic tag reader capable of remotely reading the identification tags into an electronic record of shopping cart contents when the identification tags are within a readable range from the electronic tag reader; an energy field generator other than one of the machine-readable identification tags, the energy field generator configured to generate a first detectable energy field extending from a location within the readable range of at least some of the items in the first item zone to a location outside the readable range of any of the items in the first item zone; and wherein the tag reader is movable along the aisle into and out of the first detectable energy field, and is configured not to read the identification tags on any of the first set of items while the tag reader is within the first detectable energy field and, in response to the tag reader having been moved out of the first detectable energy field, to selectively read the identification tags on any of the items taken from the first item zone into the electronic record of shopping cart contents.