C HAPTER 20: G ETTING T ECHNICAL – T HE V IDEO S IGNAL

V OCABULARY : Field: One entire pass of the electron beam, spraying every other line from the top to the bottom of the screen. Frame: Two consecutive passes of the cathode ray, spraying every line on the television screen with electrons. Two complete fields complete one frame. Genlock: Feature that allows a piece of video equipment to ignore its internal sync generator when an external sync signal is applied. Horizontal Blanking: Signal that stops the cathode from firing electrons. Horizontal Retrace: Signal that tells the cathode to re-aim the ray at the left edge of the screen and begin spraying again. Horizontal Sync Pulse: Signal sent with the video signal that tells the cathode that the ray has reached the end of a line. Interlace: Process of firing all the odd lines on the television screen with the cathode ray in one pass and returning to the top of the screen to fire all the even lines in the second pass of the cathode ray.

V OCABULARY (C ONTINUED ): Letterbox: Video display format that allows a program originally shot using a wide screen film or video format (16:9 aspect ratio) to be displayed on a normal, 4:3 aspect ratio analog television. Progressive Scan Technology: Process of firing every line on the television screen in one pass instead of every other line. The cathode ray moves fast enough to complete firing every line on the screen before the lines at the top of the screen begin to fade. Sync Generator: Device that provides a synchronization signal to all the video equipment in the television production facility. Sync Pulse: Sets a piece of equipment scanning in the same place and time. Vectorscope: Piece of testing equipment that graphically measures the way the colors are structured in the video signal. Vertical Blanking: Signal that turns off the cathode ray when it reaches the bottom of the screen.

V OCABULARY (C ONTINUED ): Vertical Retrace: Signal that returns the cathode ray position to the top of the screen to begin firing again. Vertical Sync Pulse: Signal that alerts the cathode that the last line of the screen has been sprayed. Waveform Monitor: Piece of testing equipment that measures every aspect of an image, including the brightness and darkness of the video signal.