The Digital Visual Interface (DVI) is a video interface standard designed to maximize the visual quality of digital display devices such as flat panel LCD computer displays and digital projectors.
The DVI connector usually contains pins to pass the DVI-native digital video signals. In the case of dual-link systems, additional pins are provided for the second set of data signals.
The DVI connector mays also incorporate pins to pass through the legacy analogue signals using the VGA standard. This feature was included in order to make DVI unversal, as it allows either type of monitor (analogue or digital) to be operated from the same connector.
The DVI connector on a device is therfore given one of three names, depending on which signal it implements:
DVI-D (Digital Only)
DVI-A (Analogue Only)
DVI-I (Digital & Analogue)
The connector also includes provision for a second data link for high resolution displays, though many devices do not implement this. In those that do, the connector is sometimes referred to as DVI-DL (Dual-Link).
DVI is the only widespread standard that includes analogue and digital transmission options in the same connector. Competing standards are exclusively digital: these include a system using low-voltage differential signalling (LVDS), known by its proprietary names FPD (for Flat Panel Display) Link and FLATLINK; and its successors, the LVDS Display Interface (LDI) and OpenLDI.
Some new DVD players, TV sets (including HDTV sets) and video projectors have DVI/HDCP connectors; these are physically the same as DVI connectors but transmit an encrypted signal using the HDCP protocol for copyright protection. Computers with DVI video connectors can use many DVI-equipped HDTV sets as a display.
