Magnetic grooved bar-code recognition system with slant MR sensor

For goods management in dirty factories or in outdoor environments, a scanner with a novel slant-element magnetoresistive (MR) sensor, which enables highly sensitive detection and increased detection height, has been developed. This sensor is effective for recognising a bar-code at a nearly 0.2 mm higher detection height than in a conventional single MR sensor. The usable effective detection height of 0.5 mm was obtained for a groove bar-code with two different groove depths using this sensor. It is shown theoretically that this sensor increases detection sensitivity with an increase in the number of MR sensor elements without sacrificing bar-code detection resolution