Horizontal Drive is commonly used along with Vertical Drive to synchronize monochrome or RGB video and computer display equipment. Horizontal Drive marks the interval between transmission of horizontal video scan lines.
In closed circuit video systems, horizontal drive rests at 0 Volts and is active at -4 Volts. In computer video, horizontal drive is active at +5 Volts.
Video Sync Separator, Sync Stripper, Sync Generator