Teletext still exists after 40 years: but how does it work?

The Teletext is the main service of teletext Italian, offered by Italian public television. It allowed, long before the advent of the Internet, to consult the main news in real time directly from your TV for free. Indeed, it still allows: because 40 years after its debut in Italy, in 1984the service is still alive and well, with approximately 800 pages available via the appropriate button on your remote control, usually marked with three horizontal lines inside of a rectangle.

The technology behind Teletext

As we said, Teletext is a service teletext. This technology allows you to display pages of text that can be viewed on your television. When TVs were a cathode ray tube, this data was inserted into the analog signal in the “dead times” between one video signal and another. In a cathode ray tube, electrons are emitted which are deflected and projected onto the screen. The electron source “built” the image little by little, 25 times per second, from left to right and from top to bottom. The cycle began again by directing the electron source back to the initial position. Relocating the source required a tiny amount of time in which there was no television signal, imperceptible to the human eye but enough to transmit the teletext signal.

Today we no longer have the limitations of the cathode ray tube: our televisions receive both the image reproduction information and that for the teletext pages at the same time.

Brief history of Teletext in Italy

Teletext was born in Great Britain In the 1974. The first TV broadcaster it was English who implemented it BBC using the teletext service, from which the Italianized name of derives Teletext.

In Italy the experimentation began in 1981when from research laboratories Rai of Turin teletext information was inserted into the television signal. The following year the monoscope – that still image that was typically broadcast during the hours when there were no TV programs available – was replaced by a sequence of some Teletext demonstration pages to get users used to the new service.

The official launch of Teletext took place on September 5, 1984. During the 80s there was also the introduction of the famous page 777, “that of the subtitles”. The first film transmitted by Rai to be able to take advantage of this service The rear window In the 1986.

In the 90’s Also Mediaset proposed a similar service to Teletext, called Mediavideoalways based on teletext.

Teletext is still one today information tool which continues to be integrated into our televisions. However, with the advent of the web, access to this platform has inevitably collapsed. THE reader data then they were never exhaustive as they were not detected by theAuditel (the company that collects and publishes data on Italian television ratings) but it is estimated, to date, some thousands of views per month in Italy.