horizontal blanking

Horizontal blanking is between lines and vertical blanking is between fields (half frames).

A device which functions during the horizontal blanking or synchronizing interval to fix the level of the picture signal at some predetermined reference level at the beginning of each scanning line.

These and the sync pulse itself are called the horizontal blanking (or retrace) interval and represent the time that the electron beam in the CRT is returning to the start of the next display line.

In a poorly tuned TV receiver the horizontal blanking can be seen at the right or left of the image and the vertical blanking can be seen at the top or bottom of the image.

The parameters defined by standard include horizontal blanking and vertical blanking intervals, horizontal frequency and vertical frequency (collectively, pixel clock rate or video signal bandwidth), and horizontal/vertical sync polarity.

In case of digital video line having 720 horizontal pixels, only the center 704 pixels contain actual 4:3 or 16:9 image, and the 8 pixel wide stripes from either side are called nominal analogue blanking for horizontal blanking and should be discarded before displaying the image.