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Evaluation of Cathode Ray Tube Spot

IP.com Disclosure Number: IPCOM000097196D
Original Publication Date: 1962-Jun-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Nielsen, G: AUTHOR

Abstract

The method evaluates the spot of a cathode ray tube. The cathode ray tube is energized so that a spot is displayed on its face. A camera is positioned in front of the cathode ray tube and the spot is initially photographed at a shutter speed and f-stop setting just sufficient to cause registration of the spot on the film. Relative movement is then effected between the film and the spot on the tube face. The settings of the camera, either the f-stop or the shutter speed or both, are adjusted and a second photograph is taken. A larger area of the film is exposed since the intensity of the spot decreases outwardly from its center. The steps are repeated. Successive photographs are taken with different camera settings.

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Evaluation of Cathode Ray Tube Spot

The method evaluates the spot of a cathode ray tube. The cathode ray tube is energized so that a spot is displayed on its face. A camera is positioned in front of the cathode ray tube and the spot is initially photographed at a shutter speed and f-stop setting just sufficient to cause registration of the spot on the film. Relative movement is then effected between the film and the spot on the tube face. The settings of the camera, either the f-stop or the shutter speed or both, are adjusted and a second photograph is taken. A larger area of the film is exposed since the intensity of the spot decreases outwardly from its center. The steps are repeated. Successive photographs are taken with different camera settings.

The composite photograph is a series of spots of increasing size. In the example, only the f-stop settings of the camera are changed. A brightness contour of the spot is provided. The intensity of the spot is maximum at the center and decreases outwardly of the center. The composite photograph also shows the spot shape at each intensity level.

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