The Plasma TV Blog

1080I is a shorthand name that is used to describe a certain video mode. The number 1080 refers to the number of lines of vertical resolution, and the letter I stands for interlaced scan. Interlaced scan is the original method used for the display of an image on the screen. It refers to the fact that each image or frame that is shown is displayed in a series of lines with every other line being empty. When the frame refreshes, the formerly empty line has an image, and the line that previously had an image is now empty. This alternating frame display give interlacing scan its name. The term 1080I is a HDTV mode with a wide screen aspect ratio of 16:9. Interlacing scan uses two terms, field rate and frame rate. The field rate would be expressed as a resolution of 1920 pixels multiplied by the line of vertical resolution, or 1920 x 1080 yielding about 2.07 million pixels. The frame rate, however would be expressed as 1920 x 1080/2 yielding only 1.04 million pixels because of the empty vertical lines in each frame.

The 1080I mode can be used with CRT based HDTV sets, but these models are considered out of date. They are also compatible with the newer progressive scan models, but must be deinterlaced first in order to be displayed.