Abstract: Devices and methods calibrate an optical scanner by having the scanner scan a calibration surface. The scanner includes a lens causing a distortion of items scanned. During the calibration process, such devices and methods perform a compensation process to remove the distortion from signals output by the scanner when performing the scanning to identify at least one surface irregularity on the calibration surface. After performing the compensation process, the devices and methods adjust the calibration process (using the processor) to apply correction for pixels affected by the surface irregularity. Then, after adjusting the calibration settings, such devices and methods finalize the calibration process and store the scanner settings, again using the processor.

Abstract: Devices and methods calibrate an optical scanner by having the scanner scan a calibration surface. The scanner includes a lens causing a distortion of items scanned. During the calibration process, such devices and methods perform a compensation process to remove the distortion from signals output by the scanner when performing the scanning to identify at least one surface irregularity on the calibration surface. After performing the compensation process, the devices and methods adjust the calibration process (using the processor) to apply correction for pixels affected by the surface irregularity. Then, after adjusting the calibration settings, such devices and methods finalize the calibration process and store the scanner settings, again using the processor.

Abstract: The present invention generally relates to a digital scanner for scanning images. More specifically, the present invention is directed to a method and apparatus for accurately scanning documents and for processing digital data to provide digital images stored in memory, which can be retrieved for printing on support material or for displaying on a display screen.

Abstract: The present invention is directed to a system and method for compensating for offset and gain drift in a fast scan direction during an image forming process. To achieve compensation, the present invention samples a plurality of permanently darkened pixels upon powering up image sensors and circuitry therefor and during a sub-scanning process of an image and feeds this information into an offset value generating circuit. The offset generating circuit continually adjusts a pixel offset voltage according to a difference between sequential samples of the permanently darkened pixel, thereby compensating for fast scan offset drift. The present invention also samples a plurality of active pixels during a scanning of a calibration strip. From this scan, a gain corrective value is calculated. The present invention then samples active pixels during a scanning of a platen background.