When color television refers to a way of watching TV in the ( in contrast to the black-and- white television ) not only the brightness values are recorded and played back, but also the colors.
- 4.1 United Kingdom
- 4.2 Romania
- 5.1 NTSC
- 5.2 PAL
- 5.3 SECAM
- 5.4 Digital television
Since the 18th century, we know that can be synthesized by additive color mixing because of metamerism light of ( almost) any color, by superimposing weighted (usually red, green and blue) as needed the light of a suitable primary colors.
Almost simultaneously with the development of television ever experimented with the color television. In the first experiments was carried out either with three channels, where one image was transferred to one of the three primary colors, or the transmission by means of a channel and rapidly rotating color filter in front of the camera and the receiver. Here, however, had a significantly higher number of frames to be transmitted, so that the impression of a flicker-free image is created. Guillermo González Camarena invented The Mexican 1940 the first color TV. His proven system of color image transmission was 1977/79 used in Voyager 1. The American television network CBS presented in 1943 before a color television system with fast rotating color filter. Were transmitting television pictures with only 405 rows and 144 frames per second. Although the image was very good, but the receivers were by the much larger color filter wheel in front of the small screen very clunky, noisy and not compatible with the newly introduced black and white system with 525 lines and 60 fields per second. In October 1953 was finally in the United States the era of regular color transmissions - now with a compatible for black -white- operating system - initiated. "Compatible" means in this case that color broadcasts received with conventional black -and-white television sets without major loss of quality and - could be shown - without color.
Color TV long remained very expensive despite the much earlier compared to Europe launch in the U.S., and until the late 1960s, significantly less than half the shipments was broadcast in color in the United States. The NBC showed more color broadcasts for years as competition from ABC and CBS, as at that time NBC 's parent company RCA was also the main manufacturer of color televisions. Only in 1972 were in the U.S. for the first time more color television sets sold as a black -and-white devices.
Introduction to Germany
The launch of color television in the Federal Republic of Germany took place on the 25th Great German Radio Exhibition in West Berlin on August 25, 1967 at 10:57 clock with the operation of a large red button ( the one dummy was ) by Vice Chancellor Willy Brandt. It happened a little mishap: Just before Brandt pushed the button, the technician switched already the color signal on the air - you then founded with a very sensitive button.
At 9:30 clock television channels ARD and ZDF will broadcast the Welcome Host by Edith Grobleben from Sender Freies Berlin still in black / white and the adoption in color. From 14:30 clock ARD and ZDF showed the French feature film Cartouche, the bandit with the main actors Jean -Paul Belmondo and Claudia Cardinale together as a test broadcast. On the same evening the ZDF showed its first color television show with the 25th edition of " The Golden Shot " Vico Torriani with; ARD followed a day later at 16:30 clock with a report by Gerd Ruge about the Expo 67 in Montreal and in the evening the "Gala Evening of the record ," presented by Dietmar Schönherr.
At the start of color television in 1967 Körting brought the cheapest color television on the market, a unit with 14 tubes plus CRT with two- transformer concept. These could be purchased as " Neckermann world view " about the time of his major Neckermann Versand already for 1840 DM, which was below that of its combined with a general wholesale price of the other manufacturers of about $ 2000 including tax. Generally, the retail price of a color TV was at a time when there was price fixing, at around 2400 DM For comparison it should be noted that a 1967 as "savings beetle" marketed VW 1200 was offered for 4525 DM. The Körting color TV was from the Telecommunications Technology Central Office ( FTZ ) of the German Federal Post Office, at the time, selected among others, the supervisory body for radio and television technology as a reference device for compliance with the regulations. A pioneering work was that Körting as early as the second generation of 1968 had plug-in modules.
A strong incentive to buy for color devices brought the 1972 Summer Olympics in Munich and the Football World Cup 1974 in West Germany. The devices were expensive until the late 1970s - 1975 the cost of a device with 66-cm screen around the $ 2000 (which corresponds to about 2,624 euros today ).
With the start of the second German television radio program on October 3, 1969, color television was introduced in the GDR. On the same day the Berlin TV Tower was inaugurated. For color transfer but the SECAM system was different than in West Germany used. Mutual reception (compatibility) in black and white, however, remained possible. To be able to see in the Federal Republic of Germany, the DDR program in color, at prices of up to DM 300 ( including installation ) were soon by the industry PAL / SECAM decoder ( " GDR - color" ) are offered.
- In the early days of the due to the significantly higher costs still rare color productions were preceded by the Note and as an incentive short teaser of about ten seconds duration. , " Color ": a color graphic floral rosette with the central lettering - In the First opened - with musical accompaniment of a fanfare rotating glass cubes were instead shown on ZDF, in which - as in a prism - the light (weak) color burst.
- The daily news of the ARD was first broadcast in color from 1970. Transfers from the Chamber of the Bundestag in Bonn were made until the end of the 1970s in black / white.
- Adrian of tulips thief, shot in 1966 with Heinz Reincke in the subtitled role, was the first television series in Germany - was broadcast in color - even during the experimental program.
Introduction to Austria
Austria decided on February 7, 1967 to the German PAL system as the technical standard. The first color television program of the Austrian Broadcasting Corporation was the New Year's Concert of the Vienna Philharmonic from 1 January 1969.
Launch in Switzerland on October 1, 1968 ( source Federal Archives )
The second program of the BBC, which broadcast from the beginning in 625 lines, was launched on 1 July 1967 with color broadcasts of the PAL system. With the change of the number of lines (resolution) of 405 to today's standard 625 lines followed by the first program on 20 November 1969. Yet until 1985 the first program was next broadcast in black and white with 405 lines to supply the owners of old televisions. In 1985 the recipients were finally become so cheap that it was more economical to exchange the still operated 405 -line equipment at government expense for new equipment, but to continue the 405 -line transmission.
There are from 1968, a second television in black and white. Not until 1983 that began transmission in color after the PAL television standard.
Condition in the development of ink transfer systems for analog television was for a compatibility with existing black and white television sets, on the other hand backward compatibility of the new color television sets for conventional black -and-white broadcasts. This compromises had to be accepted and typical weaknesses of the human eye has been exploited.
The frequency spectrum of the conventional black and white television is about 5 MHz wide (see television signals ). According to the laws of the Fourier analysis, the basic structures of the image to be transferred while in the lower frequencies, higher frequencies occur in fine detail on or against sharp edges. If there are ordinary recordings from the real world with the image content, the spatial brightness gradients are rather soft and hardly leaps and bounds. For this reason, higher frequencies generally occur much less frequently. One drawback of these higher frequencies, therefore, hardly manifests itself, and if so, only in a slightly less sharp image.
Looking at the spectral distribution of the luminance signal in more detail, as occur in the frequencies of the vertical distance to half the frequency with maxima respectively at a distance from the line frequency.
Because of these two facts are nested, the color signal a precisely in the upper portion of the normal television signal.
Initially they used for the separation of color and luminance signal in the receiver a simple high - or low-pass, now available for high-quality receivers special comb filter available, so that the bandwidth of the luminance signal does not have to be cut off before.
This reduces the so called cross - color and cross - luminance effects that come through crosstalk of avoid chrominance [ Color ] on the luminance [ brightness ] signal about and be reflected in changes in the images.
For the actual transfer of the color signal to use more technical tricks. It would be much too expensive and is not necessary in addition to the pre-existing luminance signal Y or the signals for the three primary colors red, green, blue, to transmit the additive color mixture. It forms a matrix, the difference signals U ( blue minus luminance ) and V ( red minus luminance, see also the YUV color model). They continue to experience a reduction in order to avoid over-modulation, and are then transmitted to the receiver together with the luminance signal to be reconstructed back to the color signals for red, green and blue.
( Red minus luminance ) plus brightness = Red ( Blue minus luminance ) plus brightness = Blue Brightness minus blue minus red = green NTSC
With the introduction of color television was a condition that the new (color) had to be compatible with the standard of the old black and white television television standard - in the population often already existing black -and-white devices should thus can also view the new color broadcasts, though of course not in color. This was first released in 1954 in the United States by the NTSC method, a technical engineering genius with only one small flaw: When an NTSC receiver, the hue must be manually adjusted. The viewer is geared to the naturalness of human skin and complexion. As a result of disturbances on the transmission had to specify this setting by hand often be carried out several times during a broadcast. The annoyance caused colloquial terms such as " Slimming machines" ( Abmagerungsmaschinen ) for the TV or the interpretation of the abbreviation as " Never The Same Color" (Never the same color). Only with the introduction of the ultrasonic remote control in 1957 the color correction was convenient.
The procedures PAL and SECAM, are used in Europe, were only in the mid -1960s introduced (more than ten years after the NTSC color television system used in the U.S.), but have at the then only existing terrestrial analog transmission significantly better quality in the color representation. They come from without manual color balance. PAL, for example, developed by the engineer and television pioneer Walter Bruch, compensates disturbances by adding a color variation, the negative copy. For this purpose, each color information per line rotated by 180 degrees in the transfer of the color information from the transmitter. With this trick color errors are compensated. Accordingly, the name of the German color TV system: PAL = translated: Phase alternating line; what to German means: changing the phase angle. Analogous to the interpretation of NTSC is also available for the abbreviation PAL a humorous statement: " Pay Additional Luxury" ( Pay for added luxury ), since one in PAL receiver to perform these electrical addition at that time a relatively expensive additional circuit component, a piezoelectric ultrasonic delay line of quartz glass needed. From the early 1990s, the now cheaper digital delay lines were instead increasingly used.
Last but not least for political reasons the SECAM process was developed in France, which also in the entire Soviet bloc (except in Romania, where PAL was used ), and was initially used in the French speaking part of Belgium, and Greece. In SECAM transmits the interference-prone phase position of the color signal - as opposed to the NTSC or PAL - no information about the ink is instead transferred to the much less affected by the propagation frequency of the chrominance signal, and therefore, no color correction is required. However, SECAM transmission also has some disadvantages.
Wherein digital video signals, the RGB signal is indeed usually further separated into a luminance signal and two color difference signals, the latter are mixed with the former, but not more, but are transferred separately ( in the YCbCr format, if necessary, with color sub-sampling ). Therefore, there is no equivalent in the digital domain to PAL, SECAM and NTSC. However, the term is often used for the PAL signals and the designation 576i50 for 480i60 NTSC signals, however, unrelated to the analog color encodings.