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Illuminator for Microfilming

IP.com Disclosure Number: IPCOM000094950D
Original Publication Date: 1965-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Huffman, HD: AUTHOR

Abstract

In accordance with the inverse-square law, light becomes weaker proportionately to the square of the distance from the source. In microfilming operations, this phenomena must be taken into account.

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Illuminator for Microfilming

In accordance with the inverse-square law, light becomes weaker proportionately to the square of the distance from the source. In microfilming operations, this phenomena must be taken into account.

In compensating for this phenomena, a document on a copyboard is scanned by a motor driven carriage containing a pair of tubular lamps. Each of these is provided with a parabolic reflector. Light impinging on the document is reflected to a microfilm camera through a curved slit.

This is proportioned wide at the ends and narrow in the center to compensate for the inverse-square law on one axis of the document. Compensation for the other axis is realized either by a variable speed carriage motor that operates more slowly at each end of the copy-board than in the middle or a variable light source and a constant speed carriage.

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