Raster scan systems

 Raster scan systems are a type of display technology used in computer graphics. They work by scanning an electron beam across the screen in a series of horizontal lines, or "scan lines," from top to bottom. As the beam scans each line, it turns on and off to create an image.

The electron beam is controlled by a series of electronic circuits that determine where the beam should be positioned and how bright it should be. The circuits receive data from the computer's graphics card, which tells them what color and intensity to use for each pixel in the image.

Raster scan systems create images by filling in each pixel one at a time, starting at the top-left corner of the screen and working their way across each row. This process is repeated for each row of pixels until the entire screen has been filled.

The resolution of a raster scan system is determined by the number of pixels it can display, which is limited by the size of the screen and the capabilities of the electronics. The refresh rate of a raster scan system is determined by how quickly it can scan each line and update the image, which is typically measured in Hertz (Hz).

Raster scan systems were commonly used in CRT (Cathode Ray Tube) monitors, which were widely used in the early days of computer graphics. However, they have largely been replaced by modern flat panel displays such as LCD, LED, and OLED, which offer higher resolutions, faster refresh rates, and better energy efficiency.