Browse Prior Art Database

Optical Configuration for Warehouse Scanning System

IP.com Disclosure Number: IPCOM000076761D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

McMurtry, DH: AUTHOR

Abstract

This optical system rearrangement affords higher contrast with large depths of field for conventional printing quality with conventional printing inks.

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Optical Configuration for Warehouse Scanning System

This optical system rearrangement affords higher contrast with large depths of field for conventional printing quality with conventional printing inks.

Bar coding (or other marking) to be sensed is printed on conventional document media including tags, labels and/or boxes 10. The boxes 10 move in the direction of the arrows from one location to another, as in warehouse operations. The printing on the box 10 is scanned in transit. The field of scan is illuminated by a source of light, having an elliptical reflector 12 at the focus of which a conventional lamp 14 is positioned. The reflector 12 is directed toward the nearest vertical plane surface of the box 10 at an angle of substantially 30 degrees to the normal, indicated by the line 16. A photoresponsive device 20 of conventional form, located beyond a slit aperture stop 21, is directed toward the box 10 at an angle substantially 10 degrees to the normal and 20 degrees from the optical axis of the reflector 12.

A polar plot of reflected light is indicated by the broken line 22, wherein the maximum value of the reflected light (specular portion) and the focus point are joined by line 24. From this plot, it can be seen that the specularly reflected light does not reach the photosensitive device 20 which increases the contrast between light and dark fields. This is particularly true with highly/reflective media and inks. Nonreflective inks are unnecessary and the...