Short span of time when the electron beam of a cathode ray tube is shut down after it has painted the last line of an image so the beam can be restarted at the top left corner to draw the next screen. It takes time for the beam to be refocused and redirected from the bottom right corner (its end point after completing a field of video data) to the top left corner (its starting point for the next field). The vertical blanking interval represents this time. uring the vertical blanking interval, the video display receives other data such as closed captioning text. In this way, the time is not wasted and the video display or television is able to receive more data and increase its utility compared to not using the vertical blanking interval for any information.