Brightness Contrast and Character Height of Five Flat Panel Computer Displays

摘要

To determine the relative legibility of the flat panel displays of five IBM-PC compatible lap-top microcomputers, their brightness contrasts and character heights, which generally contribute to legibility, were measured under normal lighting and in the dark. The Datavue 25, the Toshiba T1100 Plus, and the Zenith Z-181 used a liquid crystal display in various foreground/background color combinations. The Data General DG One had an electroluminescent display, and the Grid Gridcase 3 used a plasma display, both of which are self-luminous. The brightness contrast of all the displays was acceptable under normal lighted conditions. The DG One had the highest contrast in a lighted room (92%), at viewing angles both normal to the vertical screen surface and at 45 in the horizontal plane. The DG One and the Gridcase 3 had the highest contrast in the dark (over 98%). The Toshiba's screen was not backlighted and could not be used in a dark room. All the screens displayed 25 lines of 80 characters. The height of upper case characters ranged from 0.137 to 0.208 in., and all were acceptable for normal viewing distances.