Apparatus for and method of electro-optically reading a target in the presence of ambient light

Patent metadata

Field	Value
Publication number	US-9016579-B2
Application number	US-201313900611-A
Country	US
Kind code	B2
Filing date	May 23, 2013
Priority date	May 23, 2013
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

A reader for electro-optically reading a target in the presence of ambient light, includes a scan component for scanning a laser beam across the target, a first filter for passing return laser light from the target and the ambient light to a first photodetector system for generating a first output signal constituted of an information signal and a first ambient light signal, a second filter for passing the ambient light to a second photodetector system for generating a second output signal constituted of a second ambient light signal, and signal processing circuitry for measuring a difference between the first and second ambient light signals, for equalizing the first and second ambient light signals when the difference exceeds a threshold, and for subtracting the second output signal from the first output signal to obtain a receiver output signal substantially constituted only of the information signal.

First claim

The invention claimed is:

1. A reader for electro-optically reading a target in the presence of ambient light, comprising:
a laser for emitting a laser beam;
a scan component for scanning the laser beam across the target for reflection and scattering therefrom as return laser light;
a first filtering system for passing the return laser light from the target and the ambient light;
a first photodetector system for receiving the return laser light and the ambient light passed b…

Assignees

• Symbol Technologies Inc

Inventors

• Giebel James R
• Barkan Edward D

Classifications

• G06K7/10831 Primary

  Physics · mapped topic

• G06K7/10554

  Physics · mapped topic