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Improved Color Electro-photographic Printing/ Copying Using Patterned Photoconductor Electrodes

IP.com Disclosure Number: IPCOM000121956D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Scranton, RA: AUTHOR

Abstract

A photoconductor structure and printing device are disclosed that enable improved color printing. The invention incorporates a pattern of conductive electrodes in the photoconductor to selectively develop different colors by controlled bias voltages applied to the electrodes. Colors are developed sequentially after a single exposure, eliminating color registration problems.

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This is the abbreviated version, containing approximately 54% of the total text.

Improved Color Electro-photographic Printing/ Copying Using Patterned
Photoconductor Electrodes

      A photoconductor structure and printing device are
disclosed that enable improved color printing.  The invention
incorporates a pattern of conductive electrodes in the photoconductor
to selectively develop different colors by controlled bias voltages
applied to the electrodes.  Colors are developed sequentially after a
single exposure, eliminating color registration problems.

      After charging of the photoconductor (PC), the image is
transferred to the PC by scanning the PC with a light beam.

      In a "beam-addressed" approach, the color information is
presented serially for each color and synchronized so that the light
intensity for color "a" is presented when the laser beam is over
electrode "a", the light intensity for color "b" is presented when
over electrode "b," etc. Synchronization is accomplished by a
separate grating, or by monitoring the light reflected off, or
transmitted through, the photoconductor, or by monitoring the
photocurrent through each electrode, or by other means.

      In an alternate "bias-addressed" approach, the color
information is presented one line at a time and only the correct
electrode is biased so as to provide a drift field for the
photogenerated carrier.  Light absorbed in the region of the
photoconductor above the biased "on" electrode will produce
electron-hole pairs which drift apart under the influence of t...