11.3.1.4.1-7 Display Screen Pixel Properties
The pixel properties of the screen should produce no visible granularity, roughness, fuzziness, gaps, or jagged lines.
Additional Information: The clarity and legibility of the image on the display device screen are heavily dependent upon the pixel properties of the screen. The following are several important pixel properties that contribute to image clarity and legibility:
- For CRT visual display devices, the pixel size should be a minimum of 0.2 mm at half height.
- For displays having a pixel density of fewer than 30 pixels per degree of visual angle at the design viewing distance, the pixel grid modulation should be a maximum of 0.4 for monochrome, and a maximum 0.7 for multicolor displays when all pixels are at maximum luminance.
- For flat-panel displays having a pixel density of fewer than 30 pixels per degree of visual angle at the design viewing distance, the fill factor should be minimum of 0.3 and preferably a minimum of 0.5.
- Pixel pitch, the distance between adjacent pixels from center to center, is determined by the design viewing distance, the height of characters in number of pixels, and the height of characters in visual angle. For example, if the design viewing distance is 50 cm, the pixel pitch must be 0.25 mm for characters 16 arc minutes high, and 0.35 mm for characters 22 arc minutes high. The pixel pitch should be a maximum of 0.3mm/pixel
.
- The manufacturer of the display device should specify a Classpixel for the display. The display should be free of pixel and subpixel faults according to its Classpixel.
See IDMS (2012) for measurement information.100