Browse Prior Art Database

Lamp Intensity Control

IP.com Disclosure Number: IPCOM000093694D
Original Publication Date: 1966-Jan-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Schoonover, DA: AUTHOR [+2]

Abstract

When optically sensing marks upon a document, it is highly desirable to maintain the illumination upon the document at a constant value. The signal amplitude obtained from reading a mark on the document is proportional to the contrast ratio of the mark multiplied by the amount of illumination upon the document. Thus, the signal amplitude increases and decreases with respective increases and decreases in the amount of illumination. Light source 10 provides light for reading a plurality or mark positions on document 11. The light is transmitted from source 10 to the mark positions by a plurality of laterally spaced light transmission fiber optic bundles 12 contained in read head 13. The light from bundles 12 is directed to the individual read positions and reflected from them to receiving bundles 14.

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Lamp Intensity Control

When optically sensing marks upon a document, it is highly desirable to maintain the illumination upon the document at a constant value. The signal amplitude obtained from reading a mark on the document is proportional to the contrast ratio of the mark multiplied by the amount of illumination upon the document. Thus, the signal amplitude increases and decreases with respective increases and decreases in the amount of illumination. Light source 10 provides light for reading a plurality or mark positions on document 11. The light is transmitted from source 10 to the mark positions by a plurality of laterally spaced light transmission fiber optic bundles 12 contained in read head 13. The light from bundles 12 is directed to the individual read positions and reflected from them to receiving bundles 14. The latter direct the light to associated photosensors 15. The outputs of photosensors 15 are connected to read amplifiers not shown. The signals from these are used to provide an indication of the information read from document 11.

In order to maintain constant intensity of light 10 over its life, a separate fiber bundle 16 which includes approximately one fiber from each of the mark reading fiber bundles 12 furnishes an average illumination on each of the mark read fiber bundles 12 to photosensor 17. The output from 17 is applied to regulator amplifier 18 which, in turn, controls regulator 19. Regulator 19 controls the amount of voltage and cur...