Browse Prior Art Database

LIGHT GUIDE ILLUMINATOR

IP.com Disclosure Number: IPCOM000024490D
Original Publication Date: 1980-Oct-31
Included in the Prior Art Database: 2004-Apr-02
Document File: 2 page(s) / 92K

Publishing Venue

Xerox Disclosure Journal

Abstract

Exposure zones in conventional scan-type copiers are typically measured in fractions of an inch (in the direction of scan) in order to provide the requisite exposure energy. In comparison, and referring to Figure I, the exposure zone 3 of a Raster Input Scanner (RIS) system is much less and typically is measured in thousandths of an inch (in the scan direction).

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XEROX DISCLOSURE JOURNAL

LIGHT GUIDE ILLUMINATOR Proposed Robert F. Allis Classification

U.S. Cl. 358/285 Int. CI. H04n 1/04

IS

FIG. I 3

FIO. 2

Exposure zones in conventional scan-type copiers are typically measured in fractions of an inch (in the direction of scan) in order to provide the requisite exposure energy. In comparison, and referring to Figure I, the exposure zone 3 of a Raster Input Scanner (RIS) system is much less and typically is measured in thousandths of an inch (in the scan direction).

One desirable feature in a RIS system is a book edge support 4 permitting bound documents such as books 5 to be located in proper position on platen 6 for scanning by the movable scanning apparatus 7. However, provision of a book edge support 4 typically precludes the use of multiple exposure lamps or of larger diameter lamps in close proximity to the underside of the platen to increase irradiance. While aperture lamp/reflector combinations are quite effective illuminators due to the large solid angle subtended by the object and the reflector, arrangements of this type require particular orientation of the components in order to provide balanced illumination. Additionally, limitations on aperture size may be imposed due to the fact that although smaller apertures of increased brightness permit higher efficiency reflector designs, direct irradiance from the exposure lamp is signifi- cantly reduced.

Volume 5 Number 5 September/October 1980 547

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