Abstract: A document scanner is disclosed wherein means are provided to dynamically compensate for any changes in document illumination intensity that may occur as a document is scanned. The compensation method and apparatus operates to measure the intensity of light that is reflected from a target area that borders an edge of the document being scanned. The target area is a narrow, elongated, area that extends in the scan direction. The target area is of a color to approximate the document's background area, i.e. the document's nonimage area. Since the target area is of a continuous and uniform color tone, any variation in the quantity of light that is reflected from the target area is caused by a variation in the intensity of illumination thereof by the scanning light source. The method and apparatus of the invention controls the scanning light source so as to maintain the light reflected from the target area at a substantially constant magnitude.

Abstract: Digital data produced by a document scanner or other data source is sequentially stored in a memory. A remote data receiver generates requests for data causing communication of the data from the memory in the same sequence in which it was stored but at a rate substantially asynchronous with respect to the rate of scanner data production. Data is concurrently loaded into the memory and transferred from the memory to the receiver so that continuous data storage and transfer throughout the scan of a given image is possible. Data from the scanner is sequentially loaded into the memory in recycling sequences until there are no available memory storage sections. The scanner is then caused to stop scanning and to cease data production until transfer of data occurs from a memory storage section to the remote receiver. The scanner is thereafter enabled so as to resume with production of the next data following that which was last loaded into the memory.

Abstract: A specific dye set, comprising Acid Yellow 23, Direct Red 227, and Acid Blue 9, yields true, vivid colors on specially coated paper and transparency, and yields true colors on uncoated or "plain" papers. This dye set, which is intended for 300 dpi thermal ink-jet printers, is a distinct improvement over a prior art dye set.

Abstract: A document to be scanned is corner referenced on a transparent platen, with the document's image facing down. The platen defines an X-Y coordinate system matrix. A moving line of light extends in the X direction and illuminates the document's image, line by line, as the line of light moves in the Y direction. The line of light that is thus reflected from the document is sensed by a linear CCD sensor array having a large number of individual sensor cells arranged in a line that effectively extends in the X direction. Each cell of the CCD array defines an individual pixel (PEL) within the line of light that is reflected from the document. A reflection target is located at a known position relative to the platen's referencing corner, to be scanned prior to scanning the document.