Refreshing Methods

When only alternate rows of pixels on the screen are refreshed at a time, the display is termed Interlaced. This is usually used to reduce the data that needs to be transferred through the interface. Since this refresh occurs many times per second, it is not easily evident to the human eye, except in scenes involving fast movement, where this manifests as jagged lines. A non-interlaced display refreshes all the pixels at the same time. Non-interlaced displays are also called Progressive Displays. Normally, interlaced displays have twice the refresh rate of a noninterlaced display. Interlaced displays are usually marked with an “i”, and Non-interlaced or Progressive displays are marked “NI” or “P”. Besides monitors, media devices like DVD players and TVs are also similarly marked.