Composite monitor
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A composite monitor or composite video monitor is any analog video display that receives input in the form of an analog composite video signal to a defined specification.[1] A composite video signal encodes all information on a single conductor; a composite cable has a single live conductor plus earth. Other equipment with display functionality includes monitors with more advanced interfaces and connectors giving a better picture, including analog VGA, and digital DVI, HDMI, and DisplayPort; and television (TV) receivers which are self-contained, receiving and displaying video RF broadcasts received with an internal tuner. Video monitors are used for displaying computer output, closed-circuit television (e.g. security cameras) and other applications requiring a two-dimensional monochrome or colour image.
Inputs
Composite monitors usually use RCA jacks or BNC connectors for video input. Earlier equipment (1970s) often used UHF connectors. Typically simple composite monitors give a picture inferior to other interfaces.
In principle a monitor can have one or several of multiple types of input, including composite—in addition to composite monitors as such, many monitors accept composite input among other standards. In practice computer monitors ceased to support composite input as other interfaces became predominant.
A composite monitor must have a two-dimensional approximately flat display device with circuitry to accept a composite signal with picture and synchronisation information, process it into monochrome chrominance and luminance, or the red, green, and blue of RGB, plus synchronisation pulses, and display it on a screen, which was predominantly a CRT until the 21st century, and then a thin panel using LCD or other technology.
A critical factor in the quality of this display is the type of encoding used in the TV camera to combine the signal together and the decoding used in the monitor to separate the signals back to RGB for display. Composite monitors can be very high quality, with professional broadcast reference displays costing US$10k-$15k as of 2000. Comb filters are frequently used to improve the quality of a composite monitor.
Early innovations
Originally, these monitors were used for commercial studios. Composite video first saw home use for dubbing tapes on
Composite video and game consoles
During the same time period, home game consoles chose to stick with
Composite input to non-composite device
When a composite monitor is not available, a device requiring one can use an
Devices are available to convert from composite to other standards such as analog VGA or digital HDMI; such devices may be called
With a whole market full of all sorts of solutions to convert composite (or its related standard
Commercial use of composite monitors
- Television studios use stand-alone composite video monitors to check and judge their output picture quality. These are usually high-end professional broadcast monitors that are used to view the output of professional video cameras, VTRs, character generators, telecines and DDRs. They can also be used when new video devices are being tested. Most commercial composite monitors have no audio support or speakers, as the audio system is processed through high-quality audio equipment.
- Stand-alone composite monitors are commonly used for closed-circuit television and video surveillance.
Some monitors used in video surveillance give a monochrome picture.
Common features
- Stereo sound
- TV tuner
- Front AV inputs
- S-Video input
- Closed captioning
Other video standards
Other video standards include
- RGB video, 3 signals, red, green and blue, with synchronisation information, on three wires from a computer or other source
- Component video, 3 signals such as Y′UV or Y, B-Y, R-Y
- S-Video, 2 signals, which have the brightness (luminance) information on one cable and the color information (chrominance) on another. Most monitors with S-Video inputs also support composite inputs
- Several digital video standards, including DVI and HDMI
- VGA, an analog standard used to display digital signals
Monitors sometimes support several standards. Absence of certain video inputs may require purchase of signal adapters to reuse electronics that are otherwise incompatible.
See also
References
- ^ a b "Apple II AppleColor Composite Monitor Owner's Guide" (PDF). Apple Computer Inc. 1986. Retrieved 22 May 2021.
Input signal: composite-only sync negative 1.0±0.5 volts peak-to-peak
- ^ Edwards 2021, Early IBM PC Displays.
- ^ "200 Series Selection: 35721 Monitor, introduced 1983, original price $550". HP Computer Museum. Retrieved 22 May 2021.
- ^ "4.3in. Dual-Zone TFT-LCD PAL/NTSC Composite Monitor". ameriDroid. Archived from the original on 22 May 2021. Retrieved 22 May 2021.
Sources
- Bigelow, Stephen J. (1997). Troubleshooting and repairing computer monitors. OCLC 1151450678.
- Desposito, Joe; Garabedian, Kevin (1997). Computer monitor troubleshooting and repair. OCLC 1028562961.
- Edwards, Benj (19 April 2021) [2015]. "A brief history of Computer Displays". PC World. Australia: IDG. Archived from the original on 29 April 2021. Retrieved 14 June 2021.