Studies of Display Symbol Legibility. Part Vi. Leroy and Courtney Symbols

摘要

At vertical resolutions of 12-, 10-, 8-, and 6-scan lines per symbol height, the legibility of Courtney alphanumeric symbols, designed especially for television, was compared with that of standard Leroy symbols. These symbols were presented singly on a 525-line TV monitor, and the speed and accuracy with which they were identified by groups of subjects having normal vision were recorded. A group of subjects viewed only the Courtney symbols, while another viewed only the Leroy. The results showed that, at any resolution value, identification of Courtney symbols was no better than for Leroy. Some practice was required with the Courtney symbols before it was possible to obtain a performance equal to that of the Leroy. This study supports the findings of other experiments: that a resolution of 10 lines per symbol height remains the lowest value recommended for TV displays. (Author)