Electronic line judge (tennis)
Attempts to revolutionize tennis officiating and the judging of calls in the sport began in the early 1970s and has resulted in the design, development and prototyping of several computerized, electronic line-judge devices. The methods have been based upon the use of pressure sensors, sensors to detect magnetized and/or electrically conductive tennis balls, infrared laser beams, and most recently video cameras. The first successful public demonstration of a computerized device to make automated line calls at a professional tennis tournament was in 1974. (The Electroline-control computer pictured at the right). This original tennis electronic line judge device, invented by Geoffrey Grant, an avid tennis player, and Robert Nicks, an electronics engineer, was used in the championship finals of both the Men’s
World Championship Tennisin Dallas in May, 1974 and the Ladies’ Virginia Slimstour in Los Angeles. [Electronic Design Magazine 9 April 26, 1976, p55-57. An electronic linesman decides where the tennis ball bounces. By John F. Mason ] [http://www.geoffreygrant.com/EDM.pdf | pdf file] [Tennis Magazine January 1975, p20-22. Is the tennis lineman obsolete? by Ken Bentley. ] [http://www.geoffreygrant.com/TM.pdf | pdf file] Detail discussions of the operational principles of the device are given in the references. Although the Grant-Nicks pressure sensor based system was given rave reviews in the press [http://www.geoffreygrant.com/ElectrolineArticles.html] at its introduction and was issued USPTOpatent [http://www.google.com/patents?id=k3N8AAAAEBAJ&dq=3,982,759 | # 3,982,759] it was never commercialized.
This inaugural electronic line-judge device worked on a principle of large, thin
Mylarconductive plastic pressure sensors beneath the surface of a carpet court. It was able to distinguish between a foot and the tennis ball; the computer detected the sharp, millisecond pulse of the ball bounce striking the ground, as compared to the slowness and electronic print of player’s foot movements. Even when a foot was present on the sensor a dynamic load circuit was able to detect and distinguish between the signals. Beneath the court surface on each boundary line of the court were both and ‘IN’ and ‘OUT’ sensors so that if a ball hit the outside of the line and also hit the ‘OUT’ sensor the computer would correctly overrule the ‘OUT’ call allowing play to continue. This first electronic device made decisions, not only, as to whether the ball landed within the boundaries of the playing zones, but also, was wired to make [http://en.wiktionary.org/wiki/foot_fault foot fault] and service net-cord legal serve decisions. The foot fault judge used directional microphones to detect the striking of the ball by the player’s racquet, when serving the ball, that functioned in conjunction with a timing circuit to detected if the players foot had activated the baseline line ‘IN’ sensor immediately prior to, or during, the striking of the ball. The net cord ‘Let’ sensor was a simple piezoelectric device, initially a guitar pickup, to detect if the tennis ball touched the net during the service delivery. The service line sensors, net-cord sensor [http://en.wikipedia.org/wiki/Serve_(tennis)#A_legal_serve] and [http://en.wiktionary.org/wiki/foot_fault foot fault] devices were turned ‘on’ in unison during the process of a player serving the ball at the beginning of each point and then turned ‘off’ as the opponent returned the ball.
In its successful inaugural use, at the Men’s World Championships of Tennis 1974 finals in the
Southern Methodist Universityindoor stadium in DallasTX, the device was limited to judging only the service line. A later prototype was used to call all tennis court lines plus the net-cord as at the Ladies Virginia Slims championships in Los Angeles during 1975.
The second system that was publically demonstrated to electronically officiate line calls was introduced in Edinburgh, Scotland, UK at the Pernod sponsored tennis event in July 1977. [The (LONDON) Times-Online July 26, 1977. By Rex Bellamy.’Electronic Linesman to aid rectitude’. ] [http://www.geoffreygrant.com/Times.pdf | pdf file] . The system was invented by Lyle David Supran 18A Blackheath Rise, London S E 13, EN [http://www.geoffreygrant.com/Times.pdf | (pdf file) ] who patented electrically conductive tennis balls, a micro-computer network systems equipment and installed wires at the boundaries of the court to detect and determine the location of the contact of the ball with the surface. USPTO patents [http://www.google.com/patents?id=mdgyAAAAEBAJ&dq=4071242| # 4071242] . [http://www.google.com/patents?id=CV8TAAAAEBAJ&dq=4432058 | # 443258] and [http://www.google.com/patents?id=6PYyAAAAEBAJ&dq=4855711 | # 4855711] .
The system had some failings with respect to reliability and, like the Grant-Nicks pressure sensor device, did not emerge as a commercial product.
Commercially, the most successful system to emerge in the early experimental period of electronic officiating was the ‘ Cyclops’. Cyclops was a device used only for service line calls but functioned reliably and was used around the world for many years until new millennium video and television technology gained the spotlight. The Cyclops system was comprised of a series of infrared laser light beams projected, at a centimeter above the ground, to a receiver device across the court and then to a computer. The series of beams were aligned to accurately determine if the ball was inside the service area. This determination was only valid with respect to the main service line and not the side or center service lines. The Cyclops system was used only on show courts and covered only the main service lines. Recently, at the onset of the new millennium, the sport has begun to embrace video camera methodology to allow review of player questioned line calls on a select few ‘high’ visibility televised matches. This limited used presents a social discontinuity in that players of lesser stature that are not asked to play on show courts are being unfairly discriminated against. However, the video technology is accurate, successful and, in time it is believed, will lead to the development of systems for all courts under all competitive circumstances.
The professional tennis players associations, both the
Association of Tennis Professionalsand the Women's Tennis Associationhave approved a method and process of instantaneous re-evaluation of questionable line calls and the system of television video review has become popular.
Wikimedia Foundation. 2010.
Look at other dictionaries:
Tennis court — This article is about the sports venue. For the Revolutionary impetus, see Tennis Court Oath. Indoor tennis courts at the University of Bath, England … Wikipedia
Tennis strategy — Main article: Tennis In tennis, a player uses different strategies that both enhance his own strengths and exploit his opponent s weaknesses in order to gain the advantage and win more points. Players commonly specialize in a certain style of… … Wikipedia
Tennis terminology — The following is a list of tennis terms, sorted alphabetically.TOC|left|Contents A* Ace ndash; a serve where the tennis ball served is served in and not touched by the receiver, aces are usually powerful and generally land on or near the one of… … Wikipedia
Tennis — This article is about the sport. For other uses, see Tennis (disambiguation). Tennis The … Wikipedia
Glossary of tennis terms — Tennis portal This page is a glossary of tennis terminology. Contents A B C D E F G … Wikipedia
No-line court — Tennis portal The no line, multi colored tennis court was introduced by the World Team Tennis (WTT) league during its early years [1975 6]. The WTT presented this creative alternative tennis court as an identity logo . The no line, multi colored… … Wikipedia
Official (tennis) — A chair umpire positions himself prior to a match at Wimbledon In tennis, an official is a person who ensures that a match or tournament is conducted according to the International Tennis Federation Rules of Tennis and other competition… … Wikipedia
Volley (tennis) — Tim Henman is a serve and volleyer well known around the tennis community for his excellent touch … Wikipedia
Types of tennis match — Traditionally, tennis is played between two people in a singles match, or two pairs in a doubles match. Contents 1 Standard types of match 2 Other types of match 2.1 Canadian doubles 2.2 … Wikipedia
Women's Tennis Association — WTA Sport Professional tennis Formation date 1973 Chairman … Wikipedia