Patent ID: 6085979
Filing Date: 2000-07-11
Classification: G01V,G06K,G07G

Abstract:
An apparatus for sensing an item resting partly on a scale weigh plate of a bar code reader and partly on a checkout counter in which the bar code reader is mounted comprising:a source for producing a light beam;a plurality of mirrors for directing the light beam along a path around a periphery of the weigh plate;a detector for receiving the light beam; andan alarm coupled to the detector for alerting an operator when the item is placed in the path of the light beam;wherein the plurality of mirrors include a first mirror at a first corner of the weigh plate, a second mirror at a second corner of the weigh plate, a third mirror at a third corner of the weigh plate, and a fourth mirror within the bar code reader for directing the light beam at the first mirror;wherein the first mirror further directs the light beam along a first side of the weigh plate to the second mirror;wherein the second mirror further directs the light beam along a second side of the weigh plate to the third mirror; andwherein the third mirror further directs the light beam along a third side of the weigh plate to the detector.