Scan lines are the horizontal lines drawn by an electron gun in a cathode ray tube system to build up a picture, drawn from left to right, starting at the top.
Scan lines are the horizontal lines that an electron gun draws across the screen of a cathode ray tube, or CRT, display to form a picture. Beginning at the top left and sweeping from left to right, the beam traces a series of lines down the screen, and together these scan lines make up the complete image. The number of scan lines is a measure of a display's vertical resolution.
In analog and early digital video, the scan line structure defined how images were formed and transmitted, with formats specified by their line counts and whether the lines were drawn progressively or interlaced. Although flat-panel displays form images differently, the concept of scan lines remains part of the language of video resolution.
In commercial and professional audio-visual systems, delivering a clear image depends on the video signal reaching the display intact. The cable carrying the signal must preserve it so that the image, however it is formed, remains sharp.
Because flat-panel displays form images differently than cathode ray tubes, the concept of scan lines now mainly survives in the language of video resolution, but whatever the display technology, the video cable feeding it must preserve the signal for a sharp image.
At Windy City Wire, the focus on quality low-voltage video cable supports the clean signal paths that displays rely on. Supplying cable that preserves video integrity helps ensure that images reach commercial displays cleanly, whatever the display technology.