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Raster Graphics. Display Hardware. Cathode Ray Tube (CRT). Inside a CRT. Phosphor's light output decays exponentially; refresh at >= 60Hz. Liquid Crystal Display (LCD). Mirror: makes it reflective Back Polarizing Film: filters light, allows only certain light with desired direction to pass
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Raster Graphics Display Hardware
Inside a CRT Phosphor's light output decays exponentially; refresh at >= 60Hz
Mirror: makes it reflective Back Polarizing Film: filters light, allows only certain light with desired direction to pass Back Glass Filter: transistors and capacitors at each pixel to change the voltage that bends the light Liquid Crystal Layer: controls direction of light Negative and Positive Electrodes: hooked up to a power source. No current light hits the mirror and bounces back out. With current the liquid crystals between the common-plane electrode and the electrode shaped like a rectangle untwist and block the light in that region from passing through. Front Glass Filter: gives each subpixel in (R,G,B) triad its color. Subpixel addressing used in anti-aliasing. Front Polarizing Film: at a right angle to the back one. Inside an LCD
Raster Graphics System IO Device System Bus Display Processor CPU System Memory Frame Buffer Video Controller
Frame Buffer Refresh Refresh rate is usually 60 – 120Hz
Direct Color Frame Buffer Store the actual intensities of R, G, and B individually in the framebuffer • 24 bits per pixel = 8 bits red, 8 bits green, 8 bits blue DAC
Color Lookup Frame Buffer Store indices (usually 8 bits) in framebuffer Display controller looks up the R,G,B values before triggering the electron guns DAC Color Indices