Browse Prior Art Database

Item Sensing Using Changes in Data Rates

IP.com Disclosure Number: IPCOM000061404D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Broockman, EC: AUTHOR

Abstract

Supermarket scanners conventionally include one or more photodetectors which detect the arrival of an item to be scanned. This article suggests that items may be detected without such photodetectors by monitoring the digital data rate of the video signal produced by a continuously scanning laser beam.

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Item Sensing Using Changes in Data Rates

Supermarket scanners conventionally include one or more photodetectors which detect the arrival of an item to be scanned. This article suggests that items may be detected without such photodetectors by monitoring the digital data rate of the video signal produced by a continuously scanning laser beam.

In a quiescent state, the digital data rate of video signals produced by a continuously scanning laser beam is on the order of 1.250 MHz. When an item enters the scanned field of view, the data rate drops significantly. The drop in data rate can be detected to generate an Item Sensed signal.

One technique for detecting a change in data rate would be to use a programmable interrupt timer. At fixed intervals, a processor would read a counter, compare the new count with a previously read count and determine whether there was a significant difference between the two counts. If there was no significant difference, the processor would store the new count and reset the counter. If there was a significant difference, an Item Sensed signal would be generated.

Disclosed anonymously.

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