A Visual Evaluation Near the Threshold of Acuity of Five Color Liquid Crystal Flat Panel Displays.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1997
- Accession Number
- ADA329189
Entities
People
- Clarence E. Rash
- Howard H. Beasley
- John S. Martin
- Thomas H. Harding
Organizations
- United States Army Aeromedical Research Lab