Abstract: A document scanner for producing any combination of color or grayscale or bi-tonal document images having a selectable range of resolutions is provided that maximizes image production speed by minimizing the processing required to produce the particular type of images selected. The scanner includes an imaging camera including a high-resolution grayscale CCD sensor in combination with lower resolution red, green, and blue CCD sensors. The scanner further includes an image processing circuit for processing data generated by the grayscale and color CCD sensors into any combination of color, grayscale, or bi-tonal document images having high or low resolution. High-resolution color images are produced by superimposing the high-resolution grayscale image generated by the grayscale sensor with the lower resolution color images generated by the color CCD sensors. The image processing circuit may also produce high or low resolution, color, grayscale or bi-tonal images when selected at respectively lower bandwidths.

Abstract: A control system and method for an optical scanner of the type having a document feeding device for transporting documents to an optical scanning station is provided. The control system includes a plurality of buffer memories for temporarily storing optical data from documents processed through the scanning station, and a control circuit connected to the buffer memories and the document feeding device. The delivery rate of the document-feeding device is maximized to a level consistent with an estimated mode value of optical data present on the documents being scanned. When documents having higher than normal optical data cause the buffer memories to fill up faster then than they empty, the control circuit transmits a command to pause or slow down the delivery rate of the document feeding device upon a determination that a threshold capacity of any of the buffer memories has been exceeded or is about to be exceeded.

Abstract: A control system and method for an optical scanner of the type having a document feeding device for transporting documents to an optical scanning station is provided. The control system includes a plurality of buffer memories for temporarily storing optical data from documents processed through the scanning station, and a control circuit connected to the buffer memories and the document feeding device. The delivery rate of the document-feeding device is maximized to a level consistent with an estimated mode value of optical data present on the documents being scanned. When documents having higher than normal optical data cause the buffer memories to fill up faster then than they empty, the control circuit transmits a command to pause or slow down the delivery rate of the document feeding device upon a determination that a threshold capacity of any of the buffer memories has been exceeded or is about to be exceeded.

Abstract: A document scanner for producing any combination of color or grayscale or bi-tonal document images having a selectable range of resolutions is provided that maximizes image production speed by minimizing the processing required to produce the particular type of images selected. The scanner includes an imaging camera including a high-resolution grayscale CCD sensor in combination with lower resolution red, green, and blue CCD sensors. The scanner further includes an image processing circuit for processing data generated by the grayscale and color CCD sensors into any combination of color, grayscale, or bi-tonal document images having high or low resolution. High-resolution color images are produced by superimposing the high-resolution grayscale image generated by the grayscale sensor with the lower resolution color images generated by the color CCD sensors. The image processing circuit may also produce high or low resolution, color, grayscale or bi-tonal images when selected at respectively lower bandwidths.