Accession Number : ADA138294

Title :   An Automatic Sine-Wave Grating Controller to be Used for Contrast Sensitivity Testing.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING

Personal Author(s) : Swann,M H

PDF Url : ADA138294

Report Date : 05 Dec 1983

Pagination or Media Count : 144

Abstract : This report documents the additional design, construction, and testing of the brightness and contrast controller system which includes an embedded microcomputer. It is planned that researchers will use this controller to maintain prescribed video output of laboratory video monitors during vision research. The controller requires a video signal consisting of a sine-wave grating. A 512-element photodiode array directly measures the monitor's screen to produce an analog signal which is then digitized and stored in the computer. These data are used to compute the actual brightness and contrast of the monitor. In an attempt to complete the controller's system requirements, the controller prototype hardware was completed and partially packaged. Closed-loop system testing was performed for both the brightness and contrast control circuitry. Brightness and contrast control circuitry, a vertical synch pulse generator, a user-interface console, and power supply with additional voltage-regulator circuitry were designed and added to the existing prototype.

Descriptors :   *Visual acuity, *Video signals, *Line scanning, Video integration, Cathode ray tubes, Microcomputers, Sine waves, Brightness, Contrast, Theses, Monitors, Visibility, Target recognition, Luminance

Subject Categories : Anatomy and Physiology
      Electrooptical and Optoelectronic Devices
      Computer Hardware
      Optics
      Telemetry

Distribution Statement : APPROVED FOR PUBLIC RELEASE