How does HD work?
Television pictures are made up of thousands of tiny, varying light sources. The TV screen is still scanned the same way and the brightness information is still collected to control the light sources. Modern technology has allowed thousands of more dots on the screen, doubling the number of lines. Without the old phosphors going dim, the screen can be progressively scanned. In today’s world, we call the phosphor dot a pixel because no phosphor dots are in a plasma or LCD set. In today’s sets, the scanning from line to line tells which pixel to turn on and the brightness signal tells the pixel how strong it can shine. There are a number of HDTV scanning systems, but the most popular is 1080i. In non- technical terms, this is 1,080 lines, compared to the old 525 lines, and still Interlaced scanning. CBS and NBC use the 1080i format. Another popular format is 720p, or progressive. ABC uses the 720p format. Today’s HD sets can display either format. The 720p signal is more compatible with
