UNIQUE SCAN CLOSED-LOOP TELEVISION SYSTEM.
Abstract
In the Phase I portion of this effort, a study of display components and techniques was undertaken to determine a feasible method of implementing a closed-loop television system which does not have the objectionable line structure and false reference cues of a conventional raster scan TV system. The result of this study was the recommendation to design and fabricate a closed-loop television system employing conventional raster scan and additional vertical deflection signals to break up the line structure and produce a more nearly flat field. The additional deflection signals were to be sine waves of frequencies (1) in the range of 100 to 500 kilocycles and (2) approximately 20 megacycles. Phase II of this effort describes the design and evaluation of the recommended system. The basic pickup device employed is an electrostatic vidicon operating in a hybrid mode and the display device is a dual deflection cathode ray tube (CRT). The raster scan is generated by means of the magnetic deflection components and the additional vertical deflection is applied to electrostatic deflection plates. The primary display parameters are 945 lines, 30 frames per second, two-to-one interlace; however, provision is made for operation at 525 lines, 60 frames per second, two-to-one interlace. High frequency deflection was found to be the most effective means of reducing line structure. Low frequency sine wave deflection aids breakup of line structure but, in some cases, introduces objectionable effects such as moire' patterns and flicker. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1965
- Accession Number
- AD0630905
Entities
People
- John A. Holmquist
- Robert V. Quinlan