System for, and method of, controlling target illumination for an imaging reader

摘要

An imaging reader has an illuminating light assembly for illuminating a target with illumination light, and a solid-state image sensor with a rolling shutter for sequentially exposing an array of pixels to capture an image from the illuminated target. Target illumination is controlled by controlling an exposure time and a gain of the sensor, and by controlling an output power of the illumination light. The output power is maintained at a maximum level when the exposure time and/or the gain exceed a minimum threshold, and is lowered when the exposure time and/or the gain does not exceed the minimum threshold, while concomitantly maintaining the exposure time and/or the gain constant at the minimum threshold.

主权项

1. A control system for an imaging reader having an illuminating light assembly for illuminating a target with illumination light, and a solid-state image sensor with a rolling shutter for sequentially exposing an array of pixels to capture an image from the illuminated target, the control system comprising:
an exposure controller for controlling an exposure time of the sensor; a gain controller for controlling a gain of the sensor; an illumination controller for controlling an output power of the illumination light; and a main controller operatively connected to the exposure, gain and illumination controllers, for maintaining the output power at a maximum level when at least one of the exposure time and the gain exceeds a minimum threshold, and for lowering the output power of the illumination light when the at least one of the exposure time and the gain does not exceed the minimum threshold, while concomitantly maintaining the at least one of the exposure time and the gain constant at the minimum threshold.