Patent ID: 9313353
Filing Date: 2016-04-12
CPC Classification: H04N

Claim Text:
1. A scanner, comprising: a calibration strip having a bottom surface; an automatic document feeder (ADF) scan glass located underneath the calibration strip, the ADF scan glass having a top surface; a scan sensor located underneath the ADF scan glass, where the scan sensor can view the bottom surface of the calibration strip; an ADF to feed sheets across the ADF scan glass during a scan; a processor to control the scanner, the processor coupled to the ADF and the scan sensor; memory coupled to the processor, the memory having a debris detection module loaded therein, the debris detection module, when executed by the processor, causing the scanner to: locate a position for each long vertical streak (LVS) detected in a segment of the scan of a sheet being fed past the ADF scan glass; and compare the position of each LVS in the segment of the scan of the sheet being fed across the ADF scan glass to a scan of the calibration strip, to determine when the ADF scan glass has debris located on the top surface, wherein the scan of the calibration strip is done with no relative motion between the scan sensor and the calibration strip; the debris detection module to take corrective action when debris are located on the top surface.