Laser scanning system and scanning method for reading bar codes

US5561283A · kind A · utility

Assignee

• Symbol Technologies, LLC · US

Inventors

• Paul Dvorkis · Stony Brook, US
• Edward Barkan · Miller Place, US
• Harold Charych · Poquott, US
• James Giebel · Northport, US
• Stephen Osterweil · Plainview, US
• Sundeep Kumar · Mainz, DE
• John Barile · Holbrook, US
• Paul Poloniewicz · East Setauket, US
• Anthony Biuso · South Setauket, US
• Steven Chew · East Northport, US

Key dates

• Filing date: Oct 31, 1994
• Grant date: Oct 1, 1996
• Expiry date: Oct 31, 2014

Classification

• Technology area (CPC G): Physics
• CPC primary: G06K2207/1018
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

A scanner determines whether a target is a bar code symbol and, if so, whether that symbol is one-dimensional or two-dimensional. For two-dimensional symbols, the scanner aligns a scanning pattern with the symbol and expands the scanning pattern to reach only to the top and bottom edges of the symbol, not beyond. The scanner also has a microprocessor-control scanning engine that uses a coil to drive a scanning element and pick up feed back signals from the scanning element. A pulse-width-modulated regulator also provides fast and efficient operation for driving the coil. The scanning engine can also be designed to generate a pattern that precesses across the target, and a powerful interface to the scanning engine allows decoding and control logic to work efficiently with and independently of the scan engine.