Interlaced . Progressive scanning

Progressive scanning

(Electronic)

In the process of interlaced scanning, a frame of 625 line is divided into two parts. As a result, two fields are created, which are called even field and odd field respectively. After this, each field is scanned sequentially. This type of scanning is called interlace scanning.

interlace scanning

In this process the downward rate of the electron beam is increased, and each line is scanned in place of each alternate line, and as the scanning beam reaches the foothills of the picture frame. It is again moved to the top left and the remaining alternating line is re-scanned. Thus a frame is divided into two groups of 312.5 lines.

Benefits of interlace scanning

• The flicker is minimized by interlace scanning. 
• Scanning rate can be increased without increasing the channel bandwidth. Thus it requires less bandwidth than other systems.
• If T.V. If the number of lines in the system is increased, the channel bandwidth will automatically increase. Hence TV To increase the number of lines per frame in the system, the time interval for each line has to be reduced. Hence the speed of the electron beam has to be increased. But by increasing the speed of the electron beam The resolution of the system will be affected. Whereas in this process the rate of scanning can be increased without increasing the bandwidth.
•  It requires single band width to reduce the filler whereas in other systems double band width is required.