What do Interlaced and Progressive Scan Mean?
Digital TV’s paint pictures on-screen using one of the following scan methods: Interlaced or Progressive. In an interlaced scan display, two fields are used to scan one complete frame of video. Each field contains half the number of lines (every other scan line) in a frame. When the fields are drawn sequentially the eye perceives smooth continuous motion. In the United States, this is accomplished at a field refresh rate of 60 fields per second or 30 frames per second. The progressive scanning system displays all of the vertical scan lines are displayed in one frame. In other words, all the information for a complete picture is displayed progressively, from the top to the bottom of the screen. Progressive scanning delivers a sharp, clear image with no perceptible interline flicker. Refresh rates for progressive displays vary, most PC monitors in use today operate at 60 to 90 frames per second, whereas the DTV standard specifies a frame rate of 30 for 1080i . LINKS/GALLERY Visit any of
