What are the signals that make up a black and white all TV signal? What do each signal do?

It is composed of seven signals in five categories, namely image signals, line and field synchronization signals, line and field blanking signals, slot pulses and equalization pulses.

Function: Image signal: convert different bright and dark scenes into electrical signals with different strengths;

Line and field synchronization signal: the same frequency and phase at both ends of the transmitting and receiving terminals, that is, synchronization;

Line and field blanking signal: eliminate the line and field regression line and eliminate their interference to the image signal;

Slot Pulse: Addresses row synchronization issues during field synchronization;

Equalization pulse: solves the problem of time difference between odd and even two-field synchronous pulses.

It is composed of an all-TV signal including an image signal, a blanking signal and a synchronization signal.

The black-and-white all-TV signal is composed of a combination of image signal, composite synchronization signal and composite blanking signal. In order to ensure that the three do not interfere with each other, and can be easily and reliably separated at the receiving end, the black and white all-TV signal is composed in the following way:

1.The image signal is arranged in the forward path of the line and field scan, and the composite blanking and composite synchronization signals are arranged in the reverse path of the line and field scan.

2.The image signal is between the white and black levels, and the composite collapsing signal is specified to be slightly darker than the black level. The difference between the blanking level and the black level of the image is called the black level lift. The black level lift d is equal to 0 5 of the difference between the white level and the blanking level of the image.

3.The composite sync level has a darker level than the compound blanking level, i.e., "blacker than black". In this way, the composite synchronization signal is quite different from the image signal and the blanking signal in amplitude, and it is convenient to use a simple limiter (i.e., synchronous separation stage) at the receiving end to separate the composite synchronization signal from the whole TV signal.

The image signal and the composite blanking signal do not need to be separated, and can be directly sent to the CRT for use as an image signal.

Ask what these are for, do they work, they all use color TV.

A black-and-white TV only transmits an electrical signal that reflects the brightness of the scene, while a color TV transmits a chromaticity signal in addition to the brightness signal. Black-and-white TV signals: In addition to image signals, TV signals also include synchronous signals.

The so-called synchronization means that the line and field scanning pace of the camera end (sender) should be completely consistent with the scanning pace of the developer end (receiver end), that is, the same frequency and phase are required to obtain a stable picture. A frame of television signal is called an all-television signal, which in turn consists of an odd number of field line signals and an even number of field line signals in sequence. Color TV signal:

In the case of a color television signal, the luminance and chromaticity signals must first be transmitted separately so that the black-and-white and color televisions can reproduce the black-and-white and color images respectively. This problem can be solved by using a yuv spatial representation. The use of YUV space can also make full use of the visual characteristics of the human eye that is sensitive to brightness details and dull to color details, and greatly compresses the bandwidth of chromaticity signals.

The specified brightness signal bandwidth in China is 6MHz, while the bandwidth of chromaticity signal U and V is only. The high-frequency components of the chromaticity signal are almost all compressed, and if only two color signals are used to reflect the details of the image, the image will be blurred and the boundaries are not clear. In fact, since the luminance signal has a bandwidth of 6MHz, the details are very clear, and it can be used to compensate for the lack of high-frequency components in the chromaticity signal.

This method of using the luminance signal to compensate for the lack of high frequency of the chromaticity signal is called the high-frequency mixing method, which is similar to the principle of large-area coloring, and the image details are completely satisfied by the black and white details.

The black-and-white all-TV signal is composed of image signal, blanking signal (including row and field blanking signal, also known as composite blanking signal), and synchronization signal (including line and field synchronization signal, also known as composite synchronization signal).

The color all-TV signal includes chromaticity signal, luminance signal, blanking signal, and synchronization signal (in addition to line and field synchronization signals, it also contains a color synchronization signal).

It can be understood in this way: the color all-TV signal with the chromaticity signal removed is the black-and-white all-TV signal.

Keep it simple; The black-and-white TV signal contains only the line-field synchronization signal and the black-and-white image content of the black-to-white ladder.

The color TV signal is superimposed on the black mortar image with RGB three primary colors and color aberration signal transmission system; System; See also:

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1 Luminance signal image signal, 2 Chroma signal color signal, usually using subtractive color.

3-Color Synchronization Signal Lock signal to synchronize color decoding.

The 4-field synchronization signal is used for field synchronization.

5-line synchronization signal is used for line synchronization.

6 Test lines 19, 20 lines, used for testing, can contain real-time clock signals, slow sync TV signals (such as **, weather forecast, etc.).

7. Accompaniment signal, frequency modulation mode, usually using internal differential reception.

The signals are as follows: 1 luminance signal image signal, 2 chroma signal color signal, usually using subtractive color method.

3-Color Synchronization Signal Lock signal to synchronize color decoding.

The 4-field synchronization signal is used for field synchronization.

5-line synchronization signal is used for line synchronization.

6 Test lines 19, 20 lines, used for testing, can contain real-time clock signals, slow sync TV signals (such as **, weather forecast, etc.).

7. Accompaniment signal, frequency modulation mode, usually using internal differential reception.

When the image of a TV is displayed in black and white, since there is only black and white, only two colors of signal waveforms need to be emitted, i.e., black signal and white signal. The two hail delay signal waveforms can be represented by sine waves, where the amplitude of the white signal waveform is 100 and the amplitude of the black signal waveform is 0. In addition, since the image of a TV set is composed of black and white, it is possible to represent pixels of different colors in a black and white image by adjusting the phase of the white source's absence waveform and the black signal waveform.

Therefore, when the image of the TV is displayed in black and white, the waveform of the trichromatic signal will be composed of two sine waves, in which the amplitude of the white signal waveform is 100, and the amplitude of the black signal waveform is 0, and the pixels of different colors in the black and white image can be represented by adjusting the phase of the white signal waveform and the black signal waveform.

When the image of the TV is black and white, the waveform of the three-color signal will change into a sine wave, and the frequency of each carrier is the highest point of the frequency response curve of the jujube wheel, that is, the highest frequency value of R, G, and B. At this point, the nucleus signal of each color has been converted into a monochrome sine wave signal, which can be converted into a black and white picture.

To put it simply, there are RGB tri-color signal sources, chromatic aberration signal sources, and sound signals.

The standard says that a composite signal that transmits an image within the baseband of a television**. The all-TV signal of black-and-white TV includes: line (horizontal), field (vertical) scanning synchronization and blanking signals during the scanning reverse path, and black-and-white brightness signals scanning the forward time.

The synchronization signal synchronizes the scanning of the sending and receiving images to ensure the stable reproduction of the received images. The blanking signal is used to eliminate the interference of the bright line of the backsweep; The black-and-white brightness signal is used by a black-and-white or color television set to receive a black-and-white television image. The all-TV signal of a color TV (Figure 2) has the same content as a black-and-white TV, as well as a color synchronization signal and a chroma signal. Its chromatic synchronization signal is transmitted during the scan reverse path, and in the NTSC and PAL systems, it provides the frequency and phase reference of the color subcarriers required by the receiving decoder, and in the SECAM system, it serves as a line-sequence identification signal.

The chromaticity signal is transmitted simultaneously with the black and white luminance signal during the scanning process, which occupies a small part of the high-frequency end of the baseband. After demodulation, two chromatic aberration signals are obtained, and the black and white brightness signal occupies most of the baseband from the low frequency above, in addition to the black and white TV receiving black and white images, it also enters the matrix network with the two chromatic aberration signals, and is reduced to red, green, and blue primary color signals, and is sent to the color picture tube to display the color image after magnification.

There must be a professional for this issue because it is too professional.

To put it simply, the biggest difference between TV signals in the past and now is digital technology. However, the programs we see at home are not necessarily all digital when they are recorded or captured. It's just that we can't see it with the naked eye.

The signal strength is generally 60-75db on the user side