Accession Number : ADA329189

Title :   A Visual Evaluation Near the Threshold of Acuity of Five Color Liquid Crystal Flat Panel Displays.

Descriptive Note : Final rept.,

Corporate Author : ARMY AEROMEDICAL RESEARCH LAB FORT RUCKER AL

Personal Author(s) : Harding, Thomas H. ; Martin, John S. ; Beasley, Howard H. ; Rash, Clarence E.

PDF Url : ADA329189

Report Date : AUG 1997

Pagination or Media Count : 27

Abstract : Five color liquid crystal displays (LCDs) were perceptually evaluated near the threshold of visual acuity in a letter identification task. Stimuli consisted of all 26 capital letters of the Roman alphabet in either a 5X5 or 7X7 matrix. The subject's task was to identify the correct letter by entering the letter on a computer keyboard. The experimental design required all five subjects to be well practiced touch typists. The LCDs were matched for luminance and contrast of test targets and target image size. For each size of letter matrix, evaluations occurred over three distances: near, medium, and far. The far condition corresponded to about a Snellen 20/17 line. Visual performance was acceptable, and, even at the far condition, only a 14 percent error rate occurred. The displays with the smallest fill factor scored highest overall. In addition, two of the displays had diffusion screens placed over the display by the manufacturer. The blur caused by the diffusion screen did not hurt performance and, indeed, may have helped it under the conditions of the test. Noise arising from light passage in off pixels appeared to hurt visual acuity, even though display contrast was controlled.

Descriptors :   *LIQUID CRYSTAL DISPLAY SYSTEMS, *COLOR DISPLAYS, *VISUAL ACUITY, *FLAT PANEL DISPLAYS, PERFORMANCE TESTS, PERFORMANCE(HUMAN), OPTICAL IMAGES, HUMAN FACTORS ENGINEERING, VISUAL PERCEPTION, MAN COMPUTER INTERFACE, PIXELS, THRESHOLDS(PHYSIOLOGY), LUMINANCE, CUES(STIMULI).

Subject Categories : Electrooptical and Optoelectronic Devices
      Human Factors Engineering & Man Machine System
      Psychology

Distribution Statement : APPROVED FOR PUBLIC RELEASE