What is Shadow masking

Question

Explain the term shadow masking.

Answer 1

This method is used in the raster scan display devices. It provides much wider range of the colors in comparison to the beam penetration method. A shadow Mask CRT has 3 phosphor color dots at each pixel position. One phosphor dot emits a red light, another emits the green light and last one emits a blue light. This kind of the CRT also has 3 electron guns one for each color dot. A shadow mask grid is installed immediately behind the phosphor coated screen. The 3 electron beams are deflected and focused as the group onto the shadow mask that consists of the series of very fine holes aligned along the phosphor dot patterns. Whenever the 3 beams pass through the hole within the shadow mask, they trigger a dot triangle that emerges as the small color spot over the screen. Several colors are attained by varying the intensity levels. More than 17 million various colors may be obtained in the full color system.