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US 7,643,018 B1Granted
Twisted pair communications line system
AssigneeAvocent Corporation
InventorsSteven F. Brown, Robert R. Asprey, Winston J. Stewart, Philip M. Kirshtein
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Abstract
A transmission system for transmitting analog color video signals wherein a cable comprising multiple twisted pairs is employed, and certain of these pairs are coupled to carry selected color signals as a function of the delay provided by particular twist rates. In certain instances, selected signal delay devices are connected in circuit with certain twisted pairs. By such an arrangement, it has been found that relatively long distances between a computer and a monitor may be spanned by relatively low-cost, twisted pair cable commonly used for telephone communications.
Claims42
A video signal communicator, comprising:
- an input to receive a plurality of analog components of a video signal;
- a cable having a plurality of twisted pairs, at least two of said pairs having different relative twist rates;
- a transmission interface, coupled to the cable, to receive the plurality of analog components and selectively couple said plurality of analog components to be carried on selected ones of said plurality of twisted pairs such that a selected first one of said analog components travels on a first one of said twisted pairs having a first relative twist rate and a selected second one of said analog components travels on a second one of said twisted pairs have a second relative twist rate different from the first relative twist rate, the interface selectively coupling said plurality of analog components on said plurality of twisted pairs based on said different relative twist rates;
- a reception interface, coupled to the cable, to receive the plurality of analog components from said plurality of twisted pairs.
1 more element
A video system for communicating video on twisted pair communication lines having variable inherent propagation delay rates, comprising:
- video inputs providing respective components of a color video signal, a first transmitter coupled to a first of said video inputs, comprising:
- an input buffer coupled to receive a first of said respective components of the color video signal, and
- a differential amplifier coupled to the input buffer and providing a high frequency boost to the first of said respective components, and
- an output coupled between the differential amplifier and a first of said communication lines to communicate video component information identifying the first of said respective components to the first of said communication lines, and
- a first switch coupled to the twisted pair communication lines to apply said video component information to a selected one of said twisted pair communication lines, and
- a second switch communicating with a distal end of said twisted pair communication lines to receive said video component information from said selected one of said twisted pair communication lines,
- a delay circuit communicating with said second switch to receive said video component information, and
- a monitor output coupled to deliver said video component information to an external video monitor.
5 more elements
A video system for communicating video on twisted pair communication lines having variable inherent propagation delay rates, comprising:
- a transmitter, comprising:
- video inputs providing red, green and blue components of a color video signal,
- first, second and third transmitter processing circuits coupled to, respectively, first, second and third ones of said video inputs, each of said transmitter processing circuits including:
- a differential amplifier tuned to boost predetermined frequency portions of said red, green and blue components,
- first, second and third output pairs coupled between the respective differential amplifier and first, second and third ones of said twisted pair communication lines to communicate video information signals identifying said red, green and blue components from said respective differential amplifiers,
- a first switch coupled to a proximal end of said twisted pair communication lines to apply corresponding ones of said video information signals identifying said red, green, and blue components to selected ones of said twisted pair communication lines based on said variable inherent propagation delay rates, and
- a receiver comprising:
- a second switch communicating with a distal end of said twisted pair communication lines to receive the video information signals identifying said red, green and blue components from said selected ones of said twisted pair communication lines,
- first, second and third input pairs coupled to the second switch to receive on selected ones of said input pairs the video information signals,
- first, second and third receiver processing circuits coupled to, respectively, the first, second and third input pairs, each of said receiver processing circuits including:
- a differential amplifier tuned to boost predetermined frequency portions of said video information signals, and
- a monitor port coupled to deliver said video component information to an external video monitor.
9 more elements
A method, comprising:
- receiving a plurality of analog components of a video signal;
- providing a cable having a plurality of twisted pairs;
- ranking the plurality of twisted pairs according to their different relative twist rates;
- selectively coupling based on said different relative twist rates said plurality of analog components to selected ones of said plurality of twisted pairs at a proximal end of said cable such that a predefined one of said analog components travels on a first one of said twisted pairs having a first twist rate and a predefined second one of said analog components travels on a second one of said twisted pairs having a second twist rate higher than the first relative twist rate;
- and
- receiving the plurality of analog components from said plurality of twisted pairs at a distal end of said twisted pairs.
3 more elements
Dependencies are inferred from the claim text.