Browse Prior Art Database

Optical Scanner With Adaptive Shutter Closing Timeout

IP.com Disclosure Number: IPCOM000062248D
Original Publication Date: 1986-Oct-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Broockman, EC: AUTHOR

Abstract

This article describes an adaptive mode of operation for a class 1 optical scanner. The maximum length of time a beam shutter remains open is increased if a prior scan was bad or a slow scan is underway.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 86% of the total text.

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Optical Scanner With Adaptive Shutter Closing Timeout

This article describes an adaptive mode of operation for a class 1 optical scanner. The maximum length of time a beam shutter remains open is increased if a prior scan was bad or a slow scan is underway.

In a known type of optical scanner, a scanning operation begins when an item interrupts or breaks an item sensing beam on the approach side of a scanner window. A mechanical shutter is opened to allow a laser beam to exit the scanner window to begin scanning for a bar code label. After a certain time interval, the shutter is closed.

It is proposed that the length of time during which the shutter remains open be extended under two conditions in order to improve the chances that a bar code will be successfully read during the scan attempt.

The first condition is where a prior scan attempt did not result in a successful label read. Because the next scan attempt will probably be a re-scan of the same item, the shutter is allowed to remain open longer with the expectation that the longer scan interval will result in a successful re-scan.

The second condition is where a slow scan attempt is predicted. A slow scan attempt can be predicted by monitoring h long an item remains in the path of the item detector beam on the approach to the scanner window. The length of time the shutter remains open is extended during a slow scan condition for either of two reasons. First, because the item is moving slowly, it will take lo...