VBI

VBI, short for vertical blanking interval, is a term from traditional analog video signaling describing the portion of a video signal that occurs between the end of one frame and the start of the next. During the VBI, the display device’s beam or sampling process returns to the top of the image and no visible picture is drawn. The interval also serves as a channel for non-image data that accompanies the picture, separate from the active video.

In common broadcast standards such as NTSC, PAL, and SECAM, the VBI includes the vertical synchronization information and a window in which additional data can be transmitted without affecting the visible frame. Historically, this interval carried a variety of services and signals, including closed captions for the deaf and hard of hearing, teletext and other text-based services, as well as test signals and time codes used by technicians and broadcasters.

With the shift to digital video, the explicit analog VBI has diminished in importance for new transmissions. Digital systems often carry metadata and auxiliary information through separate data channels or formats, such as vertical ancillary data in serial digital interfaces, while preserving some of the legacy data carried in the old VBI through modern transport streams.

VBI can also refer to other uses of the acronym, such as VBI Vaccines Inc., a biotechnology company focused on vaccine development using virus-like particle technology. In general, the term in technical contexts most commonly denotes the vertical blanking interval in video signaling.