VERTICAL BLANKING (RETRACE)

The process of bringing the scanning electron beam in a CRT from the bottom of the picture back up to the top of the picture. Vertical retrace occurs between writing each field of a picture. The beam is shut off, blanked, during the retrace period. About 92% of the frame period is spent writing active horizontal lines. The remaining 8% is spent on vertical retrace. See Vertical Scanning Frequency below and Picture Frequency above.