Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Double-Scan Lockout Technique for Supermarket Scanner

IP.com Disclosure Number: IPCOM000049615D
Original Publication Date: 1982-Jun-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Dickson, LD: AUTHOR [+2]

Abstract

This article describes a technique for preventing a grocery item from being read twice during a repeated effort at a supermarket scanner having a single item detector upstream of the scanner window. In brief, if the same label is found twice within a certain time period, it is assumed that the second reading is in error. The second reading is discarded.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 69% of the total text.

Page 1 of 1

Double-Scan Lockout Technique for Supermarket Scanner

This article describes a technique for preventing a grocery item from being read twice during a repeated effort at a supermarket scanner having a single item detector upstream of the scanner window. In brief, if the same label is found twice within a certain time period, it is assumed that the second reading is in error. The second reading is discarded.

The supermarket scanner includes a single upstream item detector. The scanner is controlled by a microprocessor which includes a last label" register for storing the value of the previously found label. The microprocessor also includes a timer function for detecting the time between successive label reads.

With a single item detector, there is no way to tell which way an item is moving when it interrupts the detector. If a label is not successfully read during its first forward pass, the operator will move that item backward and then forward again to obtain a successful read. The same item may break the item detector beam twice and be read twice during this repeated scan. As a result, the scanner would see two identical items where, in fact, only a single item exists.

To prevent the same item from being read twice during a repeated scan effort, the below described subroutine can be used. The subroutine is called at the conclusion of each scan effort. If the current scan is found to be successful
(i.e., a valid label has been found), a check is made as to whethe...