OPTICAL SCANNING WITH CALIBRATED PIXEL OUTPUT.

摘要

An optical reading head system has a calibrated pixel output, consisting of a discrete value for each of a plurality of pixels. The system has a scanning station with an exposure region that includes an image region and a detector including an array of photosensitive sites that sense reflected light from the exposure region during a detector exposure period to generate a pixel output profile of the image region. There are a plurality of light sources for lighting the exposure region. Each light source emits an individually controllable amount of light to the exposure region during a detector exposure period such that the system's pixel output is acceptably calibrated. A calibration medium is supplied with a calibration region, and a target pixel output profile is defined for the calibration. The individually controllable light sources are adjusted to make the pixel output profile acceptably within range of the target pixel output profile.