Hewlett-packard Company

Craig L Miller

Steven L Webb

Paul K Mui

Edward S Beeman

Kenneth D Gennetten

Eric L Andersen

Chris Richard Gunning

Russell A Mendenhall

J Sean Fresk

A method and apparatus for duplex copying providing enhanced time to first copy is disclosed. The apparatus includes a scanner, a printer having a duplexer, and an information pipeline configured to process a data stream representing the image of page sides of the original document to be printed onto a single page of the copy product. The copier includes a processor , a computer readable memory, and a print element. The processor is configured to deliver the first two page sides of the original document to the printer for printing prior to the scanning of all subsequent pages of the original document.

Image copier having enhanced duplex capabilities; method of printing a copy of a document to produce a duplex copy product

A first embodiment of an illumination source including red LEDs, green LEDs, and blue LEDs provides illumination for a scanner. The LEDs are arranged in an array to generate spectrally and spatially substantially uniform illumination on the surface of an object, such as printed media, which is to be scanned. The arrangement of LEDs includes a plurality of groups of three LEDs. Each group of LEDs includes a red LED, a green LED, and a blue LED. The LEDs of like colors are connected in series. Power is supplied to the three groups of series connected LEDs by three current sources. The three current sources are each configured to supply a constant current to one of the groups of series connected LEDs. Each current source supplies a magnitude of current so that the resulting light provides substantially uniform illumination on the printed media. A second embodiment of the illumination source includes LEDs that can each generate light having a substantially uniform energy spectrum over the range of visible light frequencies. A third embodiment of the illumination source includes a plurality of groups of four LEDs. Each of the groups of LEDs includes a red LED, a green LED, a blue LED, and a yellow LED.

Illumination source for a scanner having a plurality of solid state lamps and a related method

A document scanner provides compensation for sensitivity nonuniformity that may exist between the individual sensor cells of the sensor array that is used to sense light reflected from a document being scanned. Compensated is provided for both dark (i.e. unilluminated) sensitivity variation and light (i.e. illuminated) sensitivity variation that may exist in the individual sensor cells of the sensor array.

Method and apparatus for providing sensor compensation

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.

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Boise, ID, United States of America

Craig L Miller