What is DVI?

Designed in 1999 by the Digital Display Working Group, DVI (Digital Visual Interface) is used to convey digital video signals between a source device – such as a computer – and a source display – such as a monitor. Its ability to transmit uncompressed or lossless digital video, support a variety of digital only/analogue only/integrated configurations, and provide Video Graphics Array (VGA) cable interface compatibility rapidly led to DVI serving as the computer industry standard. DVI is also the only widely used video standard to possess both digital and analogue transmission capabilities within a single connector: this is especially useful when it comes to VGA cable connectivity.

 

Similar to the analogue VGA cable connectors that preceded them, DVI connectors also possess DDC (Display Data Channel) pins that communicate digital information between a computer display and a video card graphics adapter. However, backwards compatibility between DVI and VGA cables is enabled through a number of these connector contacts being used to transfer VGA video signals and connect to monitors that can display them. By supporting one baseline video mode, dubbed 'low pixel format' – a screen resolution of 640×480 displayed at a refresh rate of 60 hertz – DVI and VGA compliant devices establish a common graphical denominator to ensure minimum degrees of operability between the two interfaces. Generally, DVI-A cables are used for these types of connections.

 

With one flat pin surrounded by four other pins, DVI-A connectors transmit a digital video signal produced by a graphics adapter to a VGA cable output. There, the signal is processed and converted into an analogue format which is then typically sent to a CRT monitor or entry-level LCD screen. Ultimately, VGA cables and the analogue only DVI-A cables both carry the same signal, though the process of digital to analogue conversion performed by them results in decreased signal quality.

 

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Posted by:moderator on 11th April 2016 (3268 Views)