Browse Prior Art Database

Error Location in Bar Code Scanning

IP.com Disclosure Number: IPCOM000052381D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11

Publishing Venue

IBM

Related People

Authors:
Bobart, KL Flurry, GA Kelly, MJ [+details]

Abstract

When a bar code record is scanned and decoded, errors may occur due to bar edge dislocations or other perturbations. With ETAB (Every Transition A Bit) bar code, these decoding errors tend to propagate, making a traditional byte parity error detection scheme nearly useless (as well as detrimental to density). For this reason a cyclic redundancy check (CRC) is used to detect errors; however, this can only give an indication that an error exists on a record, which is composed of many bytes, but cannot isolate the error to a single byte or group of bytes.