Patent ID: 7654454

Claim:
A method of maintaining a status of a product item, the product item including an associated interface surface, the method including, in a sensing device: (a) sensing at least one coded tag of a plurality of coded tags tiled across the interface surface, each coded tag encoding data on an identity of the product item and an identity of a region of the product item on which that coded tag is tiled, each coded tag having a structure which enables sensing and decoding of said encoded data at any orientation of the interface surface; (b) generating, using the sensed coded tag, indicating data indicative of the product item and region identities; and, (c) transferring the indicating data to a computer system, the computer system being responsive to the indicating data to update product status information stored in a data store based on the product item and region identities, wherein the product status information indicates for at least one product item, the product item identity and the status of the product item.