A document processing device includes a controller and a sensor arrangement. The sensor arrangement illuminates a surface of documents. The gradient index lens array collects light reflected from the documents and transmits at least a portion of the collected reflected light onto a photodetector array. The photodetector array generates one or more electrical signals in response to a gradient index lens transmitting light thereon. The controller derives data including image data from the one or more electrical signals. The image data is reproducible as a visually readable image of the surface of the documents. The visually readable image has a resolution such that alphanumeric characters can be extracted from the visually readable image 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 is at least about 0.03 inches.