Browse Prior Art Database

Scanner Read Performance Test Using Test Label Read Time Measurement

IP.com Disclosure Number: IPCOM000044017D
Original Publication Date: 1984-Oct-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 57K

Publishing Venue

IBM

Related People

Georgallis, GC: AUTHOR

Abstract

This article describes a read performance test for a supermarket scanner. A special, low contrast test label is placed face down on the scanner window. The time required to generate an acceptable candidate from the test label is monitored. If the time falls within a predetermined range, the scanner performance is considered acceptable. Referring to the drawing, the read performance test is initiated when a customer engineer places the test label face down on the scanner window and interrupts the item sensor beam with his hand. When the item sensor beam has been interrupted, the laser shutter is opened to begin generating a scan pattern. The time at which the shutter is opened is stored as a start time A. A check is made as to whether a candidate is found.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 86% of the total text.

Page 1 of 2

Scanner Read Performance Test Using Test Label Read Time Measurement

This article describes a read performance test for a supermarket scanner. A special, low contrast test label is placed face down on the scanner window. The time required to generate an acceptable candidate from the test label is monitored. If the time falls within a predetermined range, the scanner performance is considered acceptable. Referring to the drawing, the read performance test is initiated when a customer engineer places the test label face down on the scanner window and interrupts the item sensor beam with his hand. When the item sensor beam has been interrupted, the laser shutter is opened to begin generating a scan pattern. The time at which the shutter is opened is stored as a start time A. A check is made as to whether a candidate is found. If none is found, a check is then made as to whether system timeouts (maximum shutter-open time) are complete. If both checks are negative, the system will continue to look for a label candidate. When a candidate has been found or the system timeouts are complete, the shutter is closed. The time at which this occurs is stored as a stop time B and elapsed time is calculated as the difference of the stop and start times. A selected candidate is decoded and a modulo check is performed to determine whether the decoding has occurred correctly. Assuming it has, the decoded candidate will be printed at a point-of-sale terminal to which the scanner is...