Patent ID: 7679724

Claim:
An imaging system for enhancing imaging system performance by determining a target distance to a system target, comprising: a housing spaced from the system target at a variable target distance; an illuminator in the housing for illuminating a calibration target spaced from the housing at a calibration distance with a collimated light beam during a calibration mode of operation, and for illuminating the system target at the variable target distance with the collimated light beam during an imaging mode of operation, the collimated light beam having a beam spot of a generally constant size during both calibration and imaging modes of operation; a solid-state imager in the housing and having an array of image sensors for capturing image of the calibration target during the calibration mode, and for capturing image of the system target during the imaging mode; and a controller in the housing operative to (a) determine a first image size of the beam spot in the captured image of the calibration target during the calibration mode, the first image size being the calibration image size, (b) determine a second image size of the beam spot in the captured image of the system target during the imaging mode, the second image size being the target image size, and (c) determine the variable target distance based on the calibration distance, the first image size, and the second image size for using the variable target distance determined by the controller to enhance the imaging system performance.