Teletext

This article is about the teletext system as a whole. For the UK company whose teletext services were also branded as "Teletext", see Teletext Ltd. For the obsolete communications system, see Teletex.
Visual raster of a decoded signal frame extract from a vhs tape, showing the vertical blanking area with white contrasting signal data teletxt.
4fsc sampled VHS PAL signal frame (Luma) produced from an FM RF archive decoded via vhs-decode in 2022 with Teletext in the VBI space above the active picture area.

A British Teletext Ltd. index page from September 2001, showing news about the September 11 attacks

Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipped television sets.[1][2] Teletext sends data in the broadcast signal, hidden in the invisible vertical blanking interval area at the top and bottom of the screen.[3] The teletext decoder in the television buffers this information as a series of "pages", each given a number. The user can display chosen pages using their remote control. In broad terms, it can be considered as Videotex, a system for the delivery of information to a user in a computer-like format,[4] typically displayed on a television or a dumb terminal,[5] but that designation is usually reserved for systems that provide bi-directional communication, such as Prestel or Minitel.

Teletext was created in the United Kingdom in the early 1970s by John Adams, Philips' lead designer for video display units to provide closed captioning to television shows for the hearing impaired.[6] Public teletext information services were introduced by major broadcasters in the UK,[7] starting with the BBC's Ceefax service in 1974.[8] It offered a range of text-based information, typically including news, weather and TV schedules. Similar systems were subsequently introduced by other television broadcasters in the UK and mainland Europe in the following years. Meanwhile, the UK's General Post Office introduced the Prestel system using the same display standards but run over telephone lines using bi-directional modems rather than the send-only system used with televisions.[9]

Teletext formed the basis for the World System Teletext standard (CCIR Teletext System B), an extended version of the original system.[10] This standard saw widespread use across Europe[11][12][13] starting in the 1980s, with almost all televisions sets including a decoder. Other standards were developed around the world, notably NABTS (CCIR Teletext System C) in the United States,[14] Antiope (CCIR Teletext System A) in France[15] and JTES (CCIR Teletext System D) in Japan,[16] but these were never as popular as their European counterpart and most closed by the early 1990s.

Most European teletext services continued to exist in one form or another until well into the 2000s when the expansion of the Internet precipitated a closure of some of them. However, many European television stations continue to provide teletext services and even make teletext content available via web and dedicated apps.[17][18]

The recent availability of digital television has led to more advanced systems being provided that perform the same task, such as MHEG-5 in the UK, and Multimedia Home Platform.

  1. ^ Tanton, N. E. (28 July 1979). "UK Teletext-Evolution and Potential". IEEE Transactions on Consumer Electronics. CE-25 (3): 246–250. doi:10.1109/TCE.1979.273220. S2CID 41454481 – via IEEE Xplore.
  2. ^ Weitzel, P.; Hunter, J. R. (1999). "Teletext - Old Digits in a New Age" (PDF). Computer Science. CiteSeerX 10.1.1.15.6470. S2CID 2076939 – via BBC.
  3. ^ "The Evening Independent – Google News Archive Search". google.com.
  4. ^ Cite error: The named reference :0 was invoked but never defined (see the help page).
  5. ^ McKinlay, John (1982). "Videotex". The Australian Library Journal. 31 (3): 12–15. doi:10.1080/00049670.1982.10755457.
  6. ^ Teletext in Europe: from the analog to the digital era. Göteborg: Nordicom. 2016. ISBN 978-91-87957-20-8.
  7. ^ Cite error: The named reference :1 was invoked but never defined (see the help page).
  8. ^ "CEEFAX: world's first teletext service". BBC.
  9. ^ "Britain's Prestel". iml.jou.ufl.edu.
  10. ^ Recommendation ITU-R BT.653-3 (Teletext systems) (PDF). ITU. 1998.
  11. ^ Severson, Pernilla (28 June 2016). Super Teletext : A Social Shaping of Teletext as Locating Newness in a Media Convergence Future. Nordicom. pp. 131–149 – via lnu.diva-portal.org.
  12. ^ "Beyond new media hype - Why todays media policy debates need teletext research" (PDF).
  13. ^ "Teletext in Europe - From the Analog to the Digital Era" (PDF).
  14. ^ "Norpak - TES3/NABTS". 10 October 2006. Archived from the original on 10 October 2006.
  15. ^ "French and British slug it out in teletext battle". New Scientist. 27 November 1980. p. 581.
  16. ^ TES3 - Multistandard TV Data Encoder Platform (PDF). Ross Video.
  17. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  18. ^ Cite error: The named reference :3 was invoked but never defined (see the help page).