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

摘要

A reader for electro-optically reading a target in the presence of ambient light to be suppressed, includes a laser for emitting a laser beam, a scan component for scanning the laser beam across the target, a photodetector for detecting return laser light from the target to generate an information signal bearing information related to the target, and for concomitantly detecting the ambient light to generate an ambient light signal, and signal processing circuitry for measuring the ambient light signal, for processing both the information signal and the ambient light signal in one mode of operation when the measured ambient light signal is below a threshold, and for suppressing the ambient light signal and for processing only the information signal in another mode of operation when the measured ambient light signal at least equals the threshold.

主权项

1. A reader for electro-optically reading a target in the presence of ambient light to be suppressed, 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 photodetector for detecting the return laser light from the target and for converting the detected return light into an analog electrical information signal bearing information related to the target, and for concomitantly detecting the ambient light and for converting the detected ambient light into an analog electrical ambient light signal; and signal processing circuitry including a controller for measuring the ambient light signal, the signal processing circuitry being operative for generating the laser light without modulation when the measured ambient light signal is below a threshold to process both the information signal and the ambient light signal in one mode of operation, and for modulating the laser to generate a modulated information signal when the measured ambient light signal at least equals the threshold to suppress the ambient light signal and process only the information signal in another mode of operation.