Browse Prior Art Database

Mono/ Color Document Scan Head Using Fibers for Illumination And Imaging

IP.com Disclosure Number: IPCOM000107588D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Prakash, R: AUTHOR

Abstract

A scanning system consisting of a ribbon of spatially coherent fiber bundle, sandwiched between spatially incoherent fiber bundles is shown in Fig. 1. One end of this fiber bundle is placed in close proximity to the document to be scanned (Fig. 2).

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Mono/ Color Document Scan Head Using Fibers for Illumination And Imaging

       A scanning system consisting of a ribbon of spatially
coherent fiber bundle, sandwiched between spatially incoherent fiber
bundles is shown in Fig. 1.  One end of this fiber bundle is placed
in close proximity to the document to be scanned (Fig. 2).

      The other end is selectively tied to appropriate
electro-optical components.  The fiber layer 1, spatially coherent,
is tied to a CCD device and transports the image from document to the
CCD sensor.

      Fiber layers 2 and 3 are attached to a light source, e.g.,
solid- state laser, LED, etc., and provide illumination to the
document.

      Fig. 2 shows the document illumination and imaging resulting
from this fiber bundle.  The proposed scheme is useful in hand-held
scanners, as well as in low-usage scanners, where the scan head is
placed within 0.040 - 0.050 inches from the document.  The modulation
transfer function (MTF) performance exceeds 0.25, the performance
needs of a 300 d.p.i. scanner.

      Scanning speed improvements can be achieved by segmenting the
fiber layer 1 and coupling them to different CCD segments.  Parallel
operation of the CCD segments then permits higher scan rates.