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DVI: Digital
Visual Interface! What Is It? Monitors come supporting different video connector technologies:
VGA, DVI, DisplayPort, HDMI, or combinations. Not every monitor
supports these, so check the specifications carefully before making your
selection.
The Digital Visual Interface (DVI) is the
most popular high-quality digital connection for monitors (though HDMI is
quickly becoming its equal in popularity). 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. It was
developed by an industry consortium, the Digital Display Working Group (DDWG).
It is designed for carrying uncompressed digital video data to a compatible
monitor or projector, and is partially compatible with the High-Definition
Multimedia Interface (HDMI) standard in digital mode (DVI-D).
DVI represents a major improvement in image quality over the older VGA
standard.
The DVI interface uses a digital protocol
in which the desired illumination of pixels is transmitted as binary data.
When the display is driven at its native resolution, it will read each
number and apply that brightness to the appropriate pixel. In this way, each
pixel in the output buffer of the source device corresponds directly to one
pixel in the display device, whereas with an analog signal the appearance of
each pixel may be affected by its adjacent pixels as well as by electrical
noise and other forms of analog distortion.
Previous standards such as the analog VGA were designed for CRT-based
devices and thus did not use discrete time display addressing. As the analog
source transmits each horizontal line of the image, it varies its output
voltage to represent the desired brightness. In a CRT device, this is used
to vary the intensity of the scanning beam as it moves across the screen.
The two types of DVI interfaces are Single
Link and Dual Link. Following are the features and benefits of each:
Single Link - The Single Link interface is limited to a maximum pixel
clock of 165 Hz. It uses four (4) twisted pairs of wires (one each of Red,
Green, Blue and Clock). Maximum resolution is 1920 x 1200 at 60Hz.
Dual Link - The Dual Link interface is most common for today’s modern
LCD monitors. It provides three times as many pixels as the Single Link
interface. And its maximum clock may exceed 165 Hz. Dual Link uses six (6)
twisted pairs wires with two (2) each for Red, Green, and Blue, as well as a
pair for Clock. Dual Link’s maximum resolution is 2560 x 1600 at 60Hz. When
you use the Dual Link Interface you can use a longer cable because of its
higher bandwidth. Dual Link also provides HDCP support, which is required
for Blu-Ray playback.
If your Computer supports DVI ports, but
the Monitor does not, then a DVI to VGA adaptor is available at low cost to
solve this. Or inversely, if the Computer output is only VGA, and the
Monitor supports DVI, adaptors are available for this as well.
For our selection of Monitor Adaptors click here » |