Color television

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Color television started in 1967
Representation of a white "12" on a black background on a television; the close-up shows the individual colors that make up the numbers.
Additive color mixing, as used in color television
"Electron cannon", removed from a color television set, left: side view; clearly visible the vacuum feedthrough , right: front view; you can clearly see the exit holes of the three electron beams that control the three colors.
Color television sets sold in the Federal Republic of Germany 1967–1978 in million units
110 Pf postage stamp of the definitive series Industry and Technology of the Deutsche Bundespost Berlin (June 16, 1982) with a color television camera (based on the model of the KCK 40 from Bosch Fernseh GmbH from 1975)

When color TV refers to a type of television , (as opposed to when white television black ) not only the brightness values are recorded and played back, but also the colors .

history

It has been known since the 18th century that, due to metamerism, light of (almost) any hue can be synthesized by additive color mixing by superimposing the light of suitable primary colors (usually red, green and blue) weighted as required.

Almost simultaneously with the development of television in general, people experimented with color television. In the first experiments, either three channels were used, where an image was transmitted in one of the three primary colors, or the transmission using a channel and rapidly rotating color filters in front of the camera and the receiver. Here, however, a significantly higher number of individual images had to be transmitted in order to create the impression of a flicker-free image.

The principle of image generation in a color picture tube was patented by Werner Flechsig in 1938 . The Mexican Guillermo González Camarena invented a system of color image transmission in 1940. This was used in Voyager 1 in 1977/79 . In 1943 the American television network CBS introduced a color television system with a rapidly rotating color filter. TV pictures were transmitted with only 405 lines and 144 frames per second. The picture was very good, but due to the much larger color filter disc in front of the small screen, the receivers were very clunky, loud and incompatible with the black and white system with 525 lines and 60 fields per second that had been introduced in the meantime. In October 1953, the era of regular color transmissions - now with a system compatible with black-and-white operation - was finally introduced in the USA. "Compatible" in this case means that color broadcasts could be received with conventional black and white television sets without any major loss of quality and - of course without color - displayed.

Color televisions remained very expensive for a long time, despite their introduction much earlier than in Europe, and by the late 1960s, significantly less than half of all programs in the USA were also broadcast in color. For years NBC showed more color programs than its competitors from ABC and CBS, as NBC's then parent company RCA was also the main manufacturer of color television sets. It was not until 1972 that more color televisions than black and white televisions were sold in the USA for the first time.

Introduction to Germany

Federal Republic

Color television started in the Federal Republic of Germany at the 25th Great German Radio Exhibition in West Berlin on August 25, 1967 at 10:57 am when Vice Chancellor Willy Brandt pressed a large red button (which was a dummy ) . A minor mishap happened: shortly before Brandt pressed the button, the technicians switched the color signal to broadcast - it was then justified with a very sensitive button. However, a symbolic keystroke had been expressly announced in advance , and only a few TV viewers were actually able to follow the program in color, so that most viewers could not even notice the mistake.

At 9:30 a.m., the TV channels ARD and ZDF broadcast the welcome moderation by Edith Grobleben from the Sender Freies Berlin in black and white, and the farewell in color. From 2:30 p.m. ARD and ZDF showed the French feature film Cartouche, the bandit with the main actors Jean-Paul Belmondo and Claudia Cardinale, as a test broadcast . On the same evening, ZDF showed its first color TV show with the 25th edition of “ The Golden Shot ” with Vico Torriani ; the ARD followed one day later at 4:30 pm with a report by Gerd Ruge about the Expo 67 in Montréal and in the evening the “gala evening of the record ”, presented by Dietmar Schönherr .

In the early years, few hours a week were actually broadcast in color, and for years fewer color televisions were sold than black and white sets.

For the launch of color television in 1967 brought Körting at Neckermann color television world view color Supermatic to market a device with the shadow mask picture tube A63-11X , 14 electron tubes and transistors 33. The introductory price of 1,840  DM was below the general wholesale price of the other manufacturers at the time of around 2,000 DM including sales tax . In general, the retail price of color televisions was around 2,400 DM at a time when price control was still in effect . For comparison, it should be noted that a VW 1200 marketed in 1967 as the “Sparkäfer” was offered for 4,525 DM.

The Körting color television was selected by the Central Telecommunications Office (FTZ) of the German Federal Post Office , which at the time was the supervisory body for radio and television technology, as the reference device for compliance with the regulations. It was also a pioneering achievement that Körting already had plug-in modules from the second generation in 1968.

The 1972 Summer Olympics in Munich and the 1974 World Cup in the Federal Republic of Germany created a strong incentive to buy color devices . Measured against today's offers, the devices were comparatively expensive: around 1975 a table-top color television set with a 66 cm screen and remote control cost around DM 2,000, which currently corresponds to a purchasing power of € 2,680 in today's currency.

GDR

The Presidium of the Council of Ministers of the GDR decided to introduce color television in May 1965 and a little later set the start of the second, full-color program channel for October 3, 1969. Color television was introduced in the GDR with the start of the second program of the German television broadcasting company (DFF) and the simultaneous opening and commissioning of the Berlin television tower on the 20th anniversary of the founding of the GDR. The technical innovation went hand in hand with the desire for reformed programming. As early as 1967 Werner Lamberz , a member of the Central Committee of the SED , had confirmed that GDR television had “weaknesses in program composition”. Four years later, the new First Secretary of the Central Committee of the SED, Erich Honecker, became clearer and asked at the 8th Party Congress "to improve the programming, to overcome a certain boredom, to take account of the need for good entertainment."

In contrast to the Federal Republic of Germany, the SECAM system developed in France and also used in the Soviet Union was used for color transmission . This meant that it was initially not possible in principle to receive color broadcasts from the other part of Germany in color. Mutual reception in black and white ( compatibility ) remained possible.

In order to be able to see the GDR programs in color in the Federal Republic of Germany, the industry soon offered PAL / SECAM decoders ("GDR color") at prices of up to DM 300 (including installation). In the GDR, too, there were relatively quick solutions to this problem in the form of "craft solutions" and later retrofit kits. From the 1980s onwards, television receivers were also offered in the GDR that could receive both standards ex works.

After German reunification , the color television standard in the former GDR was changed from SECAM to PAL on the night of December 14th to 15th, 1990. At the same time, the area-wide broadcasting of the ARD television program on the frequencies previously used by the 1st program of the DFF began. From now on, a PAL decoder was required for color reproduction on older SECAM television receivers.

Others

  • In the early days, color productions, which were still rare due to the significantly higher costs, were preceded by short teasers of approx. Ten seconds duration as a reference and as a purchase incentive . In the first, a flowery color rosette graphic with the central lettering: "in color" opened up - accompanied acoustically by a fanfare; in the ZDF were instead sounds a celesta rotating glass cube accompanied shown, in which - as in a prism - the light (weak) color burst.
  • The ARD Tagesschau was only broadcast in color from 1970. Broadcasts from the plenary hall of the Bundestag in Bonn were carried out in black and white until the end of the 1970s .
  • Adrian the Tulip Thief , shot in 1966 with Heinz Reincke in the title role, was the first television series to be broadcast in color in Germany - even during the trial program.

Introduction to Austria

On February 7, 1967, Austria decided in favor of the German PAL system as the technical standard. The first color television broadcast on Austrian Radio was the New Year's Concert by the Vienna Philharmonic on January 1, 1969.

Other countries

Switzerland

Color television on Swiss television in the PAL system officially started with a ceremony on October 1, 1968 in the presence of Federal Councilor Roger Bonvin and SRG Director General Marcel Bezençon . Previously, on August 29, 1968, the quiz program Dopplet oder nüt was broadcast as a test run in color. However, many Swiss could not enjoy color television because at that time only about one percent of televisions could broadcast color. At that time, a color TV cost around CHF 3,000  , which was three months' salary or half as much as a new VW Beetle . Initially, six hours of color television were broadcast per week, similar to the situation in the Federal Republic of Germany, where the introduction took place a year earlier. In French-speaking Switzerland you needed a TV that also developed in France in addition to the PAL system SÉCAM - TV system was compatible. The Swiss Tagesschau has been broadcast in color since March 1, 1973 .

Great Britain

The second BBC program , which broadcast in 625 lines from the start, started on July 1, 1967 with color broadcasts according to the PAL system. With the conversion of the number of lines (resolution) from 405 to today's 625 lines, the first program followed on November 20, 1969. Until 1985, the first program was also broadcast in black and white with 405 lines in order to supply the owners of old television sets . In 1985 the receivers had finally become so cheap that it was more economical to exchange the still operated 405-line devices for new devices at state expense than to continue the 405-line transmission.

Romania

From 1968 there is a second television program in black and white. It was not until 1983 that color broadcast according to the PAL television standard began.

USSR

In the Soviet Union, experimental color television broadcasts began in January 1960 in an American NTSC system called OSKM ( Russian ОСКМ - Одновременная совместимая система с квадратима с квадратитурной модуля system). From the mid-1960s, the two European systems PAL and SECAM were also tested in the Soviet Union. In 1967 , SECAM was set as the color television standard. The introduction of color television in regular operation took place in November of that year on the occasion of the 50th anniversary of the Great October Socialist Revolution , i.e. in the same year. On November 7th, the beginning of regular color television and at the same time the first direct color broadcast on Soviet television was the broadcast of the parade from Red Square in Moscow.

On January 1, 1977, the central television of the USSR was completely converted to color technology, by 1987 all other regional television centers in the Soviet Union.

Color transfer

World map with the distribution of color transmission systems

The condition for the development of color transmission systems for analog television was, on the one hand, compatibility with existing black-and-white television sets and, on the other hand, downward compatibility of the new color television sets for conventional black-and-white broadcasts . Compromises had to be accepted and typical weaknesses of the human eye were exploited.

The frequency spectrum of conventional black and white television is around 5 MHz wide (see television signals ). According to the laws of Fourier analysis , the basic structures of the image are transmitted in the lower frequencies, higher frequencies occur in fine details or on sharp edges. If the image content is ordinary recordings from the real world, the spatial brightness gradients are rather soft and hardly erratic. For this reason, higher frequencies generally occur much less frequently. An impairment of these higher frequencies is therefore hardly evident, and if so, then only in a slightly blurred image.

If one takes a closer look at the spectral distribution of the brightness signal, frequencies occur at a distance of half the vertical frequency with maxima each at a distance of the line frequency.

Based on these two facts, the color signal is nested precisely in the upper range of the normal television signal.

Initially, a simple high-pass or low-pass filter was used to separate the color and brightness signals in the receiver, but now special comb filters are available for high-quality receivers , so that the bandwidth of the brightness signal no longer has to be cut off as before.

This reduces the so-called cross-color and cross-luminance effects, which are caused by crosstalk between the chrominance [color] and the luminance [brightness] signal and are reflected in changes in the images.

Further technical tricks are used for the actual transmission of the color signal. It would be far too complex and also not necessary to transmit the signals for the three basic colors red, green, blue of the additive color mixture in addition to the already existing brightness signal Y. The difference signals U (blue minus brightness) and V (red minus brightness; see also YUV color model ) are formed using a matrix . These are further reduced in order to avoid overmodulation, are then transmitted and can be reconstructed in the receiver together with the brightness signal to form the color signals for red, green and blue.

Sample calculation:

(Rot  minus Helligkeit) plus Helligkeit = Rot
(Blau minus Helligkeit) plus Helligkeit = Blau
Helligkeit minus Blau minus Rot         = Grün

NTSC

When color television was introduced, it was a condition that the new (color) television standard had to be compatible with the standard of the old black and white television - the black and white devices that were already widely available in the population should therefore also be able to display the new color broadcasts although not colored. This was first solved in the USA in 1954 by the NTSC process, an engineering stroke of genius with only one small blemish : the color of an NTSC receiver has to be set by hand. The viewer orientates himself on the naturalness of the human skin and face color. However, due to disruptions on the transmission path, this setting often had to be made manually several times during a broadcast. The anger over this led to slang terms like “slimming machines” for the television set or the interpretation of the abbreviation as “ N ever T he S ame C olor” (never the same color). Color correction only became more convenient with the introduction of the ultrasonic remote control in 1957.

PAL

The PAL and SECAM procedures , which are used in Europe , were not introduced until the mid-1960s (more than ten years after the NTSC color television system used in the USA), but they have significantly better quality for the then only terrestrial analogue transmission in the color shade representation. You get by without manual color matching. PAL, for example, developed by the engineer and television pioneer Walter Bruch , compensates for disturbances by adding a negative copy to a color shade deviation. For this purpose, when the color information is transmitted from the transmitter, one color information item per line is rotated by 180 degrees. This trick compensates for color errors. Accordingly, the name of the German color television system: PAL = translated: phase alternating line; which means in German: changing the phase position. Analogous to the reinterpretation of NTSC, there is also a joking explanation for the abbreviation PAL: " P ay A dditional L uxury" (Pay for additional luxury), since the PAL receiver used a relatively expensive additional circuit component to carry out this electrical addition at that time, namely a piezoelectric ultrasonic delay line made of quartz glass. From the early 1990s, the now cheaper digital delay lines were increasingly used instead.

SECAM

Not least for political reasons, the SECAM process was developed in France, which was also used in the entire Eastern Bloc (except in Romania , where PAL was used) and initially also in the French-speaking part of Belgium and in Greece . With SECAM, the phase position of the color signal, which is prone to interference - in contrast to NTSC and PAL - does not carry any information; instead, the color is transmitted at the frequency of the color signal, which is much less influenced by the propagation conditions, so no color correction is required. However, SECAM also has some transmission technology disadvantages.

Digital television

In the case of digital video signals, the RGB signal is usually still broken down into a brightness signal and two color difference signals, but the latter are no longer mixed with the former, but transmitted separately (in YCbCr format, possibly with color subsampling ). There are therefore no equivalents to PAL, SECAM and NTSC in the digital sector. However, the designation PAL is often used for 576i50 signals and the designation NTSC for 480i60 signals, but without reference to the analog color coding.

Web links

Wiktionary: Color television  - explanations of meanings, word origins, synonyms, translations

literature

  • Siegfried Liebscher u. a .: radio, television, sound storage technology , VEB Verlag Technik, Berlin 1985, DNB 850995833 .
  • Walter Bruch, Heide Riedel: PAL - Das Farbfernsehen , Deutsches Rundfunk-Museum , Berlin 1987, DNB 871514893 .
  • Andreas Fickers: "Politique de la grandeur" versus "Made in Germany". Political cultural history of technology using the example of the PAL-SECAM controversy (= Paris historical studies , Volume 78). Oldenbourg, Munich 2007, ISBN 978-3-486-58178-2 (Dissertation RWTH Aachen 2002, 436 pages).
  • Boris Fuchs: NTSC, SECAM, PAL - why are there three color television systems? Walter Bruch would have turned 100 on March 2, 2008 (= series on media history , Volume 5), in: Deutscher Drucker 1965, Volume 44, 2008, No. 31: pp. 31–32 DNB 103100520X .

Remarks

  1. The primary colors correspond to selected spectral lines within the color spectrum that is created when white sunlight is fanned out into the spectral colors by a prism . It is sufficient to superimpose the three spectral lines, which represent red, green and blue, with appropriate weighting in order - according to the principle of additive color mixing - to produce the color impression of white light or any other light color in the human eye.
  2. ^ "Der Spiegel" of August 21, 1967
  3. Industry / color television price maintenance: Black channels , Der Spiegel, August 21, 1967, p. 31.
  4. Ulrich von Pidoll: The VW Beetle and its German competitors ( Memento from August 1, 2009 in the Internet Archive ) , IG Historische VWs Braunschweig, accessed on April 20, 2011.
  5. This figure was based on the template: Inflation was determined, has been rounded to a full 10 euros and relates to last January.
  6. See the introductory text to the film series curated by Thomas Beutelschmidt at the German Historical Museum and the German Broadcasting Archive : On behalf of the GDR television. Retrieved September 26, 2019 .
  7. http://www.vienna.cc/d/historie/historie02.htm
  8. ^ Introduction of color television in Switzerland, October 1, 1968. In: bar.admin.ch. Swiss Federal Archives , accessed on October 5, 2018 .
  9. Susan Misicka: Switzerland celebrates 50 years of color television. In: swissinfo.ch. Swissinfo , October 1, 2018, accessed on October 5, 2018 .
  10. "Que la couleur soit!" - 50 years of color television in Switzerland. In: blick.ch. Blick.ch , September 27, 2018, accessed on October 5, 2018 .
  11. Chronicle 50 years of the Swiss daily news. ( PDF ) In: srf.ch. SRF , October 7, 2003, accessed October 5, 2018 .
  12. Andreas Fickers received a Friedrich Wilhelm Prize from the Rheinisch-Westfälische Technische Hochschule Aachen 2006 for this study ( online at perspectivia.net )