Patent ID: 8925814
Filing Date: 2015-01-06
Classification: G06K

Abstract:
1. An apparatus for electro-optically reading a target in the presence of ambient interference light to be mitigated, comprising: a laser drive including a laser diode for emitting a laser beam having an adjustable output power, and a monitor photodiode for monitoring the output power of the laser beam with a responsivity characteristic; a scan drive for scanning the laser beam across the target for reflection and scattering therefrom as return laser light; a photodetector for generating an output signal by detecting the return laser light from the target to convert the detected return laser light into an analog electrical information signal bearing information related to the target, and by concomitantly detecting the ambient interference light to convert the detected ambient interference light into an analog electrical ambient interference light signal; signal processing circuitry for processing the output signal, the signal processing circuitry including a controller operatively connected to the laser drive and operative, in a reading mode of operation, for initially adjusting the output power to a test power level, and for subsequently increasing the output power for a predetermined time period from the test power level to an elevated power level at which the information signal of the processed output signal has a greater magnitude than that of the interference light signal to mitigate the presence of the ambient interference light, and for subsequently decreasing the output power to the test power level after elapse of the predetermined time period; and a power safety arrangement for checking the output power of the laser beam in the reading mode, the power safety arrangement including a first power monitor operatively connected to the laser diode for testing the output power at the test power level, and a second power monitor operatively connected to the monitor photodiode for testing the output power at the test power level and at the elevated power level.