As a former television child, the footage displayed on a screen of a size and size represents almost all memories of childhood, from the educational program of infant language learning to children's entertainment of the Windmills, or engaging cartoon animations, played by various stars. The sentiments of men and women, as well as special interviews with breaking news ... TV as an important and unique window that can accept and understand information, affects the trillion population. However, once it comes to the most familiar, the most impressive picture, it is a seemingly meaningless, fixed with a slight difference in the change, a variety of colors, lines, graphics composed of the screen, its appearance, in In the eyes of ordinary viewers, it only represents a stop or interruption of the television signal.
Whenever the last program of the night is finished, such still pictures will be played long time instead of the colorful pictures of the day. It is usually a combination of large blocks and lines, some of which will be added with the English name of the station or Time, more taste with classical music as accompaniment. Although it is less frequently seen in high-level TV stations, it is a frequent visitor to many regional local stations. In fact, this kind of painting seems to have a picture of Mondrian's geometric abstract painting art, not just It is used to fill the screen with no signal. It is a pattern with practical use. There is a very simple and easy to understand name - "TV signal test chart". The English word is Test Card or Test Pattern. Drawings for test use.
The TV signal test chart refers to the television station broadcasting the special television graphics for the majority of users or maintenance personnel to adjust, test and repair the television receiver, except for the broadcast time of normal television programs.
The history of the test chart almost spans the history of television, but it was not the way it was now.
As early as January 27, 1926, Baird in the United Kingdom successfully transmitted a picture using a television-like device, and the development and development of television began to rise. Most of the early television transmissions were laboratory tests using the static test chart Baird 30-line system.
In 1934, some simple pattern pictures were used to test the TV picture. In this way, the standardized picture can test different output terminals. The concept of the TV test chart was then used up to now.
Early UK TV Test Screen
In just 10 years, television had been making rapid progress in the 1930s. Britain began transmitting song and dance programs and television broadcasts in 1936. Before the outbreak of World War II in 1939, about 20,000 families in the UK had televisions.
At the same time, U.S. television began to use another TV test screen RCA TK-1, commonly known as the Indian avatar test chart. This is a test screen for black-and-white TVs. Compared with previous versions of the UK, it added images. Lines, contrast brightness and other reference-related messages, and in some areas when playing, also matched the American national anthem as accompaniment. Indian avatar's test screen has been used since the 1940s until the 1970s. Before the appearance of color television, Main TV test chart for North and South America.
Each graph has a representative test meaning
The BBC is not inferior to that. In 1948, the BBC TV test chart already had a prototype of a modern test card. There are also many different kinds of inexplicable patterns of test screens in different levels of channels.
The same is the test card graphics for the BBC monochrome TV era
The emergence of color television has become an epoch-making significance, and the test card also has new developments. The BBC Test card F is a very famous test card. It was used for the first time in 1967. This is the first test to transmit colored models. Pictured, Carole Hersee, who was only 8 years old, playing with a clown doll is commonly used as a test chart. She was born in 1958 and has passed half a year this year. This is a colorful test chart of this cute little loli and doll. It has been used until 1998, and it can also be regarded as the collective memory of the British people. Because it is so famous, there are a lot of European cottage models. For example, Sweden has a similar LORI test chart.
This is not the most original version of Carole and the Test Card F. The BBC has many variations. It has been used for nearly 30 years.
Of course, TV test maps around the world have their own unrestrained or brain-opening designs before the standardization is unified. Interested parties can view this foreign language website and have a brief introduction to television test patterns at different times.
// MHP Test card galaxy (mainly UK based, stop in 2000)What emerged at the beginning of the article is the most common test pattern in memory. A test pattern named PM5544 is often referred to as Philips pattern or PTV circle. In 1968, Philips TV in Copenhagen. The laboratory was designed and gradually became the mainstream international standard test screen in the 1980s and 1990s. The BBC and major companies around the world also began to use the PM5544, and the collective memory of the people of the Celestial Kingdom has also largely originated.
Philips' color television and early recorders in the last century
In fact, it can be subdivided into nine different patterns, each with a subtle difference in color, typeface and various details. If the test charts of PM5544 used by different provincial and municipal TV stations are arranged together, it is simply death level. "Find your sister" game.
Of course, PM5544 also has a fixed arrangement of rules and standards, and it is not the inspirational works of artists who sway creative ideas. Each one contains interpretable information.
The proportions, lines, colors, frequencies, or values ​​that can be perceived by the human eye, or even the information that needs to be monitored by the instrument, can be transmitted from one signal to the other through this seemingly simple test pattern. Among the signal televisions, users or maintenance personnel in different regions, according to a unified standard for debugging and maintenance, or reference to determine the TV output, can not but say that the test chart a masterpiece of the combination of image information and technology.
Although the CCTV test chart changed to become a more cool electronic big circle test chart (ordinary version), people also said that these are memories of childhood memories, but in fact, the use of PM5544 has not disappeared, in most local TV stations still use Familiar with the painting.
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