Browse Prior Art Database

Bar Half Bar Reader System

IP.com Disclosure Number: IPCOM000080641D
Original Publication Date: 1974-Jan-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Gaston, CA: AUTHOR

Abstract

Depicted in Fig. 1 is a bar-half bar reader and its associated signal conditioning circuitry. The bar-half bar code 10 is a sequence of vertical bars of half or full height, representing a sequence of binary 0's and 1's. The system herein described permits considerable vertical misalignment, while requiring only two photosensors 12 and 14 to read the code 10.

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Bar Half Bar Reader System

Depicted in Fig. 1 is a bar-half bar reader and its associated signal conditioning circuitry. The bar-half bar code 10 is a sequence of vertical bars of half or full height, representing a sequence of binary 0's and 1's. The system herein described permits considerable vertical misalignment, while requiring only two photosensors 12 and 14 to read the code 10.

The technique employed is to utilize an interleaved fiber optics bundle 16, which has a reading end adjacent to the coded document 18 and a sensing end divided into two paths. Light from light source 11 illuminates document 18. Light from the sensing end of fiber optics bundle 16 is reflected into upper photosensor 12 or lower photosensor 14 by vibrating reed 20. The signals from photosensors 12 and 14 are then coupled into the associated signal conditioning circuitry.

Fig. 2 indicates more clearly the technique described above. The vibrating reed 20 has mirrored surfaces at the end, which reflect the light from one pair of fibers at a time into the two photosensors 12 and 14. At the moment that the tip of reed 20 is between fibers "6" and "F", the upper photosensor 12 is "looking" through fiber "6" while the lower photosensor 14 is detecting light through fiber "F". The fibers are arranged so that "6" and "F", for example, are separated at the reading end by the height of a half bar.

Referring again to Fig. 1, the output from photosensors 12 and 14 drive binary thresholds 22 and 2...