KR940000967Y1 - Chrominance switching circuit for multi-image processing system - Google Patents

Abstract

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Description

Color signal switching circuit of multi image processing system

1 is a circuit diagram according to the present invention.

* Explanation of symbols for main parts of the drawings

10, 60: 1st, 2nd buffer part 20, 30: 1st, 2nd trap circuit

40, 70: 1st, 2nd switch 50, 80: 1st, 2nd switching drive part

101, 102: first and second input terminals 103, 104: second and second selection terminals

Q1-Q4: Transistor R1-R7: Resistance

C1-C2: Capacitor

The present invention relates to a multi-image processing system, and more particularly, to a color signal switching circuit that selects and reproduces color signals extracted from a plurality of composite video signals having different signal types and S-VHS type color signals. It is about.

Currently, one of the video signal methods for recording and reproducing video is the S-VHS method developed by FVC of Japan. In the S-VHS scheme, the horizontal resolution is increased to 400 lines or more by increasing the bandwidth and the PM carrier frequency of the luminance signal, respectively, compared to the conventional VHS scheme. As a result, even fine details can be clearly reproduced. In particular, the maximum value of the luminance signal is increased to 210% to obtain high definition image quality at the image boundary. High quality audio is also achieved by recording and playing back Hi-Fi audio.

In the composite video signal, image quality is degraded due to mutual interference of the luminance signal and the color signal, whereas in the S-VHS method, the interference signal as described above is eliminated by separating and inputting the luminance signal and the color signal.

On the other hand, in a video processing system such as TV, VTR, A / V (Audio / Video) system, a plurality of composite video signals having different signal types, for example, PAL and SECAM composite video signals, are combined into one system. It can be handled. Such an image processing system is generally called a multi image processing system.

In the multi-image processing system, the S-VHS video signal for realizing high quality as well as a plurality of composite video signals is applied to the color signal reproducing processor of the system for color signal reproduction because the signal is separated and accumulated as the luminance signal and the color signal as described above. Must separate the composite video signal such as PAL and SECAM. That is, the S-VHS system color signal may be applied to the color signal reproduction processing unit as it is, but the composite video signal should extract and apply the color signal. Each color signal must be selectively switched according to the reproduction mode modE and applied to the color signal reproduction processing unit.

Accordingly, an object of the present invention is to provide a color switching circuit capable of selectively switching and reproducing a color signal according to a signal method from a plurality of complex video signals having different signal types.

Another object of the present invention is to provide a color signal switching circuit capable of selectively switching color signals and S-VHS system color signals extracted from a plurality of complex video signals having different signal formats according to the input signal. In providing.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a circuit diagram according to the present invention, and includes a first input terminal 101 for inputting a plurality of composite video signals, a transistor Q1, and a resistor R1 to complex the first input terminal 101. A first buffer unit 10 by buffering an image signal, a first trap circuit 20 for extracting a color signal when the buffered composite image signal is a first system signal, and the buffered composite image When the signal is a second method signal, the first and second trap circuits 20 according to the second trap circuit 30 for extracting the color signal and the signal method of the composite video signal input to the first input terminal 101. A first selection terminal 103 for inputting a first selection signal for selecting one of the color signals of < RTI ID = 0.0 > 30 < / RTI > and color signals of the first and second trap circuits 20 and 30 by predetermined control. And a first switch 40, a transistor Q2, and a resistor R2-R3 to form a first switch of the first selection terminal 103. A first switching driver 50 for driving the switching of the first switch 40 by a tack signal, a second input terminal 102 for inputting an S-VHS color signal, a transistor Q3 and a resistor ( A second buffer unit 60 including R4-R6) and capacitors C1-C2 to buffer the S-VHS system color signal of the second input terminal 102, and the first and second input terminals 101; Second selection terminal 104 for inputting a second selection signal for selecting one of an S-VHS color signal of the second buffer unit 60 and a color signal of the first switch 40 according to the signal input of the second and second buffer units 102 and 102; ), A second selection terminal 104 for inputting a second selection signal for selecting one of the S-VHS type color signal of the second buffer unit 60 and the color signal of the first switch 40, and the A second switch 70 for selectively switching and outputting the S-VHS system color signal of the second buffer unit 60 and the color signal selected and switched by the first switch 40 by a predetermined control, the transistor Q4 and the resistor ( R And a second switching driver 80 which drives the switching of the second switch 70 by the second selection signal of the second selection terminal 104.

Hereinafter, an operation example of FIG. 1 according to the present invention will be described in detail.

First, a plurality of composite video signals having different signal types are input to the first input terminal 101 of FIG. 1. In the present invention, a composite video signal of PAC type is input as a first type signal and a SCEAM type is used as a second type signal. It is assumed that the composite video signal is input.

In addition, the S-VHS type color signal is input to the second input terminal 102, and the first and second selection terminals 103 and 104 are input according to the signals input to the first and second input terminals 101 and 102. The first and second selection signals for selecting and switching the corresponding signals by the user's selection and applying them to the color signal reproduction processing unit of the system are applied from a system control microcomputer (not shown).

In the above state, a case in which one of the composite video signal of the PAL method or the composite video signal of the SECAM method is input to the first input terminal 101 will be described.

The PAL composite video signal or SECAM composite video signal is applied to the base terminal of the transistor Q1 of the first buffer unit 10, buffered, and simultaneously applied to the first and second trap circuits 20 and 30. . Here, the first and second trap circuits 20 and 30 may use a general color signal trap circuit to extract color signals of PAL and SECAM composite video signals having different color signal bands, respectively.

The first trap circuit 20 extracts a color signal when the input signal is a PAL composite video signal, and extracts a color signal on the second trap circuit 30 when the input signal is a SECAM composite video signal. The extracted color signal of the first trap circuit 20 is applied to the first terminal T1 of the switch 40, and the extracted color signal of the second trap circuit 30 is the second terminal of the switch 40. Is applied to T2.

As described above, the first selection signal 103 is input to the first selection terminal 103 and applied to the base terminal of the transistor Q2. In this case, the first selection signal is applied as a logic high when the PAL color signal is selected and as a logic yellow when the SECAM color signal is selected. Accordingly, when the first selection signal is high, the transistor Q2 is turned on and the first switch 40 is selectively switched to the first terminal T1. When the first selection signal is low, The transistor Q2 is turned off and the first switch 40 is selectively switched to the second terminal T2.

The color signal selected and output by the first switch 40 is applied to the second terminal T2 of the second switch 70.

Meanwhile, as described above, the second selection signal 104 is input to the second selection terminal 104 and applied to the base terminal of the transistor Q4. In this case, the second selection signal is applied as a low when the S-VHS type color signal is selected and is high when the PAL or SECAM type color signal is selected. Accordingly, since the PAL or SECAM signal is input processed, the second selection signal is applied to the high level, and the second switch 70 is selectively diseased by the second terminal T2 by turning on the transistor Q4. .

Therefore, the color signal is selectively switched according to the signal method of the composite video signal input to the first input terminal 101 and applied to the color signal reproduction processing unit.

In the following description, the second S-VHS system color signal is input to the second input terminal 102 to be processed. The S-VHS system color signal is transmitted through the capacitor C1 of the second buffer unit 60. After being applied to the base terminal and buffered, it is applied to the first terminal T1 of the second switch 70.

At this time, since the S-VHS type color signal is input processed, the second selection signal is applied to the second selection terminal 104 in a low speed unlike the first case described above to turn off the transistor Q4. The two switches 70 are selectively switched to the first terminal T1.

Therefore, the S-VHS system color signal input to the second input terminal 102 is selectively switched and applied to the color signal processor.

As described above, in the multi-image processing system, a color signal extracted according to a signal method and a color signal of an S-VHS method may be selectively switched and reproduced according to an input signal in a plurality of composite video signals having different signal types. There is an advantage.

Meanwhile, in the above description, an example of input processing of two composite video signals of the PAL or SECAM method is given, but it may be easily applicable to the input of a larger number of composite video signals as necessary.

Claims (6)

A color signal switching circuit of a multi-image processing system which inputs and reproduces a plurality of different composite video signals of a signal method and color signals of an S-VHS method, comprising: extracting color signals of a band from an input composite video signal according to a signal method; Selected by the first selection signal input corresponding to the signal method of the input composite video signal among the first and second trap circuits 20 and 30 and the output color signals of each of the first and second trap circuits 20 and 30. A first switching means for switching and outputting the second switching means for selectively switching the input S-VHS system color signal and the output color signal of the first switching means by a second selection signal input corresponding to the input color signal; Color signal switching circuit of the multi-image processing system, characterized in that. The method of claim 1, further comprising: a first input terminal 101 for inputting a composite video signal, and a connection between the first input terminal 101 and input terminals of the first and second trap circuits 20 and 30; And a first buffer unit (10) for buffering the composite video signal. The method of claim 2, wherein the first switching means selects one of the color signals of the first and second trap circuits 20 and 30 according to a signal method of the composite video signal input to the first input terminal 101. A first selection terminal 103 for inputting a first selection signal, a first switch 40 for selectively switching and outputting color signals of the first and second trap circuits 20 and 30 by predetermined control; And a first switching driver (50) for switching the first switch (40) by the first selection signal of the first selection terminal (103). The second buffer of claim 3, wherein the second switching means buffers the second input terminal 102 for inputting the S-VHS system color signal and the S-VHS system color signal of the second input terminal 102. A unit 60 selects one of an S-VHS color signal of the second buffer unit 60 and a color signal of the first switch 40 according to signal inputs of the first and second input terminals 101 and 102. One of a second selection terminal 104 for inputting a second selection signal, one of an S-VHS system color signal of the second buffer unit 60 and a color signal selected and switched by the first switch 40 is controlled. And a second switching driver 80 for driving the switching of the second switch 70 by the second selection signal of the second selection terminal 104. Color signal switching circuit of the multi-image processing system, characterized in that. A color signal switching circuit of a multi-image processing system which inputs and reproduces a plurality of composite video signals having different signal types and S-VHS type color signals, comprising: a first buffer unit 10 for inputting and buffering a composite video signal; The first and second trap circuits 20 and 30 extracting color signals of the first and second bands from the buffered composite video signal, respectively, and the first and second trap circuits 20 and 30, respectively. A first switch 40 for selectively switching output by driving according to a first selection signal input for selecting one of the first and second band color signals according to the signal type of the input composite video signal, and an S-VHS scheme A second buffer unit 60 for inputting and buffering a color signal, one of a color signal selected and switched by the second switch 40 and a buffered S-VHS type color signal of the second buffer unit 60 may be used as an input signal. Driving according to the second selection signal input for selecting according to the signal method And a second switch 70 which selects and outputs the selected signal by switching between the first and the second selection signal inputs so that one of the first and second color signals and the S-VHS type color signal are switched. And a color signal switching circuit of the multi-image processing system. The method of claim 5, wherein the first switching driver 50 for driving the first switch 40 in response to the first selection signal input, and the second switch 70 in accordance with the second selection signal input And a second switching driver (80) for driving the color signal switching circuit of the multi-image processing system.