Browse Prior Art Database

ENHANCED RESOLUTION VIDICON

IP.com Disclosure Number: IPCOM000024377D
Original Publication Date: 1980-Jun-30
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 117K

Publishing Venue

Xerox Disclosure Journal

Abstract

A portable raster input scanner for electronically reading a document image and storing the resultant video information with or without audio comment on magnetic tape, such as a video cassette, may be desirable. For this purpose, a vidicon may be contemplated as the scanner since devices of this type can generally be made highly portable, have modest illumination requirements (equal or close to typical offie levels), are silent in operation and draw relatively small amounts of electrical power (typically, 100 watts). Furthermore, vidicon technology has been conveniently interfaced with low-cost video tape recording hardware for some years. It appears that the only factor precluding the use of vidicons from document raster scanning applications is the vidicon's limited resolution.

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XEROX DISCLOSURE JOURNAL

ENHANCED RESOLUTION VIDICON Stephen H. Rowe

5

1

Proposed Classification
U.S. C1. 358/225 Int. Cl. G02b 13/16

F/G. 2

A portable raster input scanner for electronically reading a document image and storing the resultant video information with or without audio comment on magnetic tape, such as a video cassette, may be desirable. For this purpose, a vidicon may be contemplated as the scanner since devices of this type can generally be made highly portable, have modest illumination requirements (equal or close to typical offie levels), are silent in operation and draw relatively small amounts of electrical power (typically, 100 watts). Furthermore, vidicon technology has been conveniently interfaced with low-cost video tape recording hardware for some years. It appears that the only factor precluding the use of vidicons from document raster scanning applications is the vidicon's limited resolution.

Volume 5 Number 3 May/June 1980 297

[This page contains 1 picture or other non-text object]

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ENHANCED RESOLUTION VIDICON (Cont'd)

In Figure 1, a portable, vidicon-based raster scanner having enhanced resolution is shown. Scanner 2 comprises a camera tube 3 with homogeneous photoconductive target 4 for electronically reading a document 5. Reduction lens 6 images the document 5 onto a grating 7. From grating 7 the image is imaged by relay lens 8 onto the photoconductive target 4. To avoid vignetting of the image, grating 7 may be placed close to a field lens 9 or the grating could be a thin photographic emulsion deposited onto a suitably etched scattering screen (having the correct polar properties).

The transmitting stripes of the grating 7 are arranged to be narrower than the effective scan line width of vidicon 2. As an example, Figure 2 shows a configuration aimed at obtaining a fourfold improvement in resolution. In this example, the primary electron beam 11 is made to scan each line four times. Between each of these scans the grating 7 is shift...