10/19 Monitors CRT monitors: Flat-panel displays Electron guns Phosphors Shadow Masks varieties Raster scan lines field Flat-panel displays

2A: How many colors are there? Name colors possible mode Standard VGA 16 4 bit 256 color mode 256 8 bit High Color 65,536 16 bit True Color 16,777,216 24 bit VGA: Video Graphics Array SVGA: Super VGA XGA: Extended Graphics Array

3. Sending it to the monitor 3 electron guns RED, GREEN, BLUE CRT: “Cathode Ray Tube” video card’s signals tell the intensity needed for each gun

4. The magnetic yoke The magnetic deflection yoke bends the electron beams from the guns. Think of the electron guns as the gas pedal and the magnetic yoke as the steering wheel

4A. Terms Resolution: # pixels displayed horizontally and vertically Refresh rate: how quickly the image is redrawn

5. The Shadow Mask Purpose: to keep the electron beams sharp and on target.

5. The Shadow Mask: Types Dot pitch: distance from one hole’s center to another.

5. The Shadow Mask: Types Aperture Grille: “Stripe Pitch” -- distance from center of column to the next.

5. The Shadow Mask: Types Slot Mask: “Stripe Pitch” -- distance from center of column to the next.

6. The Phosphors Material that glows. Different type for each color. “Persistence”: phosphor keeps glowing after electron beam leaves.

7. Raster scanning Raster: the area that is hit by the electron beams, line by line. Each line is called a scan line. Field: a complete sweep of the screen. Refresh: rate usually at least 60/sec (60 Hz)

9. The cheap way out. “Interlacing”: scan every OTHER line. Can be seen sometimes as a flicker.

Flat-panel LCD Displays Passive-matrix vs. Active-matrix Resolution limitations Considerably more expensive than CRTs image courtesy of Viewsonic.com

Flat-panel Plasma Displays Brighter than LCD Easier to manufacture (theoretically) Mainly used for large-scale applications image courtesy of Viewsonic.com