Patent ID: 8781206

Claim:
A document processing device, comprising: an input receptacle configured to receive a stack of documents; a transport mechanism configured to transport the documents, one at a time, in a transport direction from the input receptacle along a transport path to one or more output receptacles; a sensor arrangement positioned adjacent to the transport path, the sensor arrangement comprising: i) at least one light source configured to illuminate at least a portion of a surface of one of the documents; and ii) a gradient index lens array configured to collect light reflected from the surface of the one of the documents and to transmit at least a portion of the collected reflected light onto a photodetector array; and a controller operatively coupled with the sensor arrangement, wherein the photodetector array generates one or more electrical signals in response to the gradient index lens transmitting the at least portion of the collected reflected light, the one or more electrical signals being transmitted from the photodetector array to the controller, the controller configured to derive data including image data from the one or more electrical signals, the image data being reproducible as a visually readable image of the surface of the document, the visually readable image having a resolution such that alphanumeric characters can be extracted from the image data in response to the document remaining within a depth of field of the gradient index lens array while being transported via the transport mechanism, the depth of field being at least about 0.03 inches, the gradient index lens array having a shifted focal plane such that movement of the documents by the transport mechanism past the gradient index lens array is constrained such that the documents are within a distance perpendicular to the shifted focal plane, the distance being about one-half of the depth of field.