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Photographic Characterization of Fiber Optic Read Heads

IP.com Disclosure Number: IPCOM000080837D
Original Publication Date: 1974-Feb-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Erickson, GD: AUTHOR [+2]

Abstract

In a fiber optic read head utilizing aligned pairs of fiber optic elements it is the practice to inspect fabricated assemblies, by measuring the total light transmission of each full and half channel using a specified light source and a photodetection device. Using this method makes diagnosis of the cause of low-light transmission difficult,since it is not possible to identify which head, emitter or receiver is causing a problem.

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Photographic Characterization of Fiber Optic Read Heads

In a fiber optic read head utilizing aligned pairs of fiber optic elements it is the practice to inspect fabricated assemblies, by measuring the total light transmission of each full and half channel using a specified light source and a photodetection device. Using this method makes diagnosis of the cause of low- light transmission difficult,since it is not possible to identify which head, emitter or receiver is causing a problem.

To both inspect and directly diagnose the head causing a problem, a photographic film is held in contact with the emitter head exit channels, while passing light through the optic fibers to expose the film. The same procedure is used with the receiver head channels to obtain a 1:1 photographic display of each head assembly. The resulting film negatives and/or positives from each head can now be compared and measured directly, since each is a direct 1:1 replica of the light transmission patterns from the respective emitting and receiving channels.

The films can easily be enlarged to simplify visual examination, and an overlay technique (where the emitter head negative or positive is placed over the emitter head negative or positive) is used to detect misalignment, assembly warpage, etc. Also, direct dimensional measurements are easily obtained from the film (s), whereas such measurements made on the heads themselves are difficult to perform and correlate and could damage the polishe...