KR970004924Y1 - Broadcasting system self-converting circuit - Google Patents

Abstract

None.

Description

Broadcasting method automatic switching circuit

1 is a conventional broadcast switching circuit diagram

2 is an automatic switching circuit diagram according to the present invention

FIG. 3 is a waveform diagram of each part shown in FIG.

* Explanation of symbols for main parts of the drawings

4: video signal processing unit 5: amplification unit

6: tuning unit 7: transistor

8 coil 9, 14 condenser

10, 13: resistance 11: integral part

12: smoothing capacitor 15, 17: comparison unit

16: constant voltage source 18: microcomputer

The present invention relates to a broadcast type automatic switching circuit, and particularly for television and video tape recorders capable of simultaneously receiving and signal-processing NTSC broadcast signals and PAL-M broadcast signals. The present invention relates to a broadcasting method automatic switching circuit for comparing a characteristic difference of color signals among broadcast signals to be switched so that a signal processing circuit capable of signal processing the determined broadcasting signal can be automatically driven.

In general, the multicasting system allows a user to selectively watch various broadcasting methods through a single TV. The types of multicasting are largely NTS broadcasting system, PAL-M and PAL-N. It is divided into broadcasting method and SECAM broadcasting method.

Here, NTS broadcast method is adopted in South Korea and Asia, Pal broadcast method is mainly used in North Korea or the Soviet Union, Secam broadcast method is used in Europe, such as France.

In this case, since the horizontal and vertical synchronization frequency and the polarity of the horizontal and vertical synchronization signal are different from each other according to each broadcasting method, each signal capable of signal processing of each broadcasting method when receiving each broadcasting method. Processing circuits must be provided separately.

On the other hand, recently, a plurality of signal processing boards are often mounted simultaneously in a single TV so as to process a plurality of broadcasting methods according to a consumer's request. By operating the slide switch to operate the signal processing board suitable for the broadcasting mode by checking, various types of multicasting can be selectively watched.

A conventional broadcast method switching circuit will be described with reference to FIG.

However, the present invention is limited to a circuit for automatically switching between the NTS broadcast system and the PAL-M broadcast method, so that all the following descriptions are limited to the NT broadcast method and the PAL-M broadcast method. Shall be.

As shown, the constant voltage source 1 which can be operated by the user and is supplied with a predetermined voltage is connected to the first input terminal ⓐ, and the second input terminal ⓑ is grounded to the ground and predetermined according to the user's selection. The slide switch 2 to output the voltage or the ground voltage and the output terminal ⓒ of the slide switch 1 are supplied with a predetermined voltage or a ground voltage selectively output by a user's operation to receive a signal according to the voltage. The microcomputer 3 which selectively operates a processing circuit is comprised.

According to the conventional broadcasting method switching circuit configured as described above, when the user manipulates the slide switch 2 so that the first input terminal ⓐ and the output terminal ⓒ are connected, the predetermined voltage applied from the constant voltage source 1 is reset. It is applied to the microcomputer 3 through the first input terminal ⓐ and the output terminal ⓒ, and the microcomputer 3 determines the magnitude of the applied voltage and thus is the first broadcast method (for example, NC broadcast method or ARM-). After recognizing that the M broadcast method is selected, the corresponding signal processing circuit is operated.

In addition, when the user operates the slide switch 2 so that the second input terminal ⓑ and the output terminal ⓒ are connected, the ground voltage is input to the microcomputer 3 through the second input terminal ⓑ and the output terminal ⓒ. The microcomputer 3 determines the magnitude of the applied voltage, recognizes that the second broadcast method (eg, P-M broadcast method or NC broadcast method) is selected, and then operates the signal processing board.

However, in the case of the above, the user has to check the broadcasting method to be applied to the slide switch in accordance with the corresponding broadcasting method, so that the user becomes cumbersome, the user does not have enough knowledge about the broadcasting method can not check the broadcasting method correctly or Alternatively, when the user fails to operate the slide switch, the color signal is removed and a screen that is processed in whitening is displayed.

The present invention is to solve the above problems, an object of the present invention is to automatically determine the corresponding broadcast method using the color signal characteristic difference of the applied broadcast method, and to determine the corresponding signal processing circuit according to the determined broadcast method The present invention provides a broadcast type automatic switching circuit for automatically operating.

In accordance with an aspect of the present invention for achieving the above object, the broadcast method automatic switching to receive the NTS broadcast signal and Pal-M broadcast signal and to automatically operate the corresponding broadcast signal processing circuit according to the received broadcast method A circuit, comprising: video signal processing means for checking a phase of a color signal of a received broadcast signal and outputting an automatic phase control error signal in accordance with the phase of a checked color signal, and a predetermined size of an automatic phase control error signal output from the video processing means. Amplification and tuning means for amplifying a predetermined frequency band of the autophase control error signal by outputting the signal and outputting a predetermined voltage value according to the state of the tuned signal, and smoothing and integrating the predetermined voltage value output from the amplification and tuning means. An integrating means for converting the constant voltage value and a predetermined constant voltage value outputted by the integrating means, It outputs a control signal according to the comparison result to the microcomputer is provided with an automatic broadcasting system conversion circuit having a comparing means for automatically operating the signal processing means to process the broadcast signal.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a broadcasting method automatic switching circuit diagram according to the present invention, the video signal processing unit 4 determines the phase information of the color signal among the received video signals to detect an automatic phase control error signal (APC Error). Output

The amplifier 5 amplifies the automatic phase control error signal applied from the video signal processor 4 to a predetermined size and then outputs the amplified automatic phase control error signal.

The tuning unit 6 is composed of a constant voltage source (not shown), a transistor 7, a coil 8, a capacitor 9, and a resistor 10 so as to tune a predetermined frequency band through the amplifier 5. The predetermined frequency band set among the amplified automatic phase control error signals is tuned.

The integrating unit 11 is composed of a smoothing capacitor 12, an integrating element of the resistor 13 and the capacitor 14 to smooth and integrate the frequency band tuned by the tuning unit 6.

The comparator 15 is composed of a comparator 17 for comparing the value integrated by the integrator 11 with a predetermined voltage value applied from the constant voltage source 16 to output the result to the microcomputer 18 The signal processing circuit corresponding to the applied broadcasting scheme is controlled to operate.

The operation of the broadcasting method automatic switching circuit according to the present invention having such a configuration is as follows.

Table 1 below shows the differences between the phases and frequencies of the horizontal and vertical synchronous signals of NTS broadcast system and PAL-M broadcast system.

Table-1

In the case of using the difference of color frequency to distinguish between NTS broadcast system and PAL-M broadcasting method, it is difficult to discriminate color frequency difference because the difference of color frequency according to each broadcasting method is very small value. have.

Therefore, in this design, the broadcasting method is distinguished using the phase shift of the color signal.

First, when the broadcast signal is received, the video signal processor 4 checks the phase of the received broadcast signal.

In this case, since the phase of the color signal does not change as shown in (a) of FIG. 3 in the case of the NTC broadcast system, an automatic phase control error signal having a constant state is output every one horizontal period. (A) Reference)

The automatic phase control error signal output from the video signal processor 4 is amplified to a predetermined size by the amplifier 5 as shown in (b) of FIG. 4, where the automatic amplified by the amplifier 5 is amplified. The phase control error signal appears in the frequency band of 15KHz in the NC broadcast method.

In the automatic phase control error signal amplified by the amplifier 5, only a predetermined frequency band is tuned by the tuning unit 6, and a predetermined voltage in a "high" or "low" state is output according to the tuned result.

At this time, if the predetermined frequency band set in the tuning section 6 is set to 7.8 KHz equal to the frequency value of the automatic phase control error signal output in the case of the ARM-M broadcasting system, the automatic phase control output from the tuning section 6 is performed. The error signal value is different from the frequency value of the set frequency band and the automatic phase control error signal in the NC broadcast method, so that the tuned frequency value is weak and a predetermined voltage in the "low" state is output.

The predetermined voltage in the " low " state output after being tuned by the tuning unit 6 is integrated into the constant voltage of a predetermined size through the integrating unit 11, at which time the value integrated by the integrating unit 11 is In the case of the SS broadcasting system, as shown in FIG. 4C, the value becomes less than 1 volt V and is output to the bar front end (+) of the comparator 17 configured in the comparator 15.

On the other hand, when the constant voltage source 16 having the 2-volt (V) value is configured to apply the 2-volt (V) reference voltage to the inverting terminal (-) of the comparator 17 configured in the comparator 15, the integrating unit A value less than 1 volt (V) applied after integration through (11) becomes a value smaller than 2 volts (V), which is a reference voltage value, and the comparator 17 outputs a control signal in a "low" state.

This control signal is applied to the microcomputer 18, where the microcomputer 18 causes the arm-M broadcast signal processing circuit to operate when the applied control signal is in the "high" state, and the applied control signal is " In the low state, when the NC broadcast signal processing circuit is set to operate, the control signal output from the comparator 15 is in the "low" state. Control to operate.

Next, when the PLM signal is received, the video signal processor 4 checks the phase of the received broadcast signal when the broadcast signal is received.

In this case, as shown in FIG. 3B, the phase of the color signal is changed every horizontal period, so that the automatic phase control error signal in which the phase is inverted every horizontal period is output. See (d) of FIG.).

The automatic phase control error signal output from the video signal processor 4 is amplified to a predetermined size by the amplifier 5 as shown in (e) of FIG. 4, wherein the automatic amplified by the amplifier 5 is amplified. The phase control error signal appears in a frequency band of 7.8 KHz in the case of the ARM-M broadcasting system.

In the automatic phase control error signal amplified by the amplifier 5, only a predetermined frequency band is tuned by the tuning unit 6, and a predetermined voltage in a "high" or "low" state is output according to the tuned result.

At this time, if the predetermined frequency band set in the tuning unit 6 is set to 7.8 KHz equal to the frequency value of the automatic phase control error signal outputted in the case of the ARM-M broadcasting method, the automatic phase control error output from the tuning unit 6 If the frequency of the signal is set to 7.8 KHz, the automatic phase control error signal value output from the tuning unit 6 is equal to the frequency value of the set frequency band and the automatic phase control error signal in the case of ARM-M broadcasting. The predetermined voltage in the "high" state is output.

The predetermined voltage in the " high " state output after being tuned by the tuning unit 6 is integrated into the constant voltage of a predetermined size through the integrating unit 11, wherein the value integrated by the integrating unit 11 is PAL-M. In the case of the broadcast method, as shown in FIG. 4E, the signal is output to the non-inverting end (+) of the comparator 17 configured in the comparator 15 with a value of 3 volts (V) or more.

The predetermined voltage in the " high " state output after being tuned by the tuning unit 6 is integrated into the constant voltage of a predetermined size through the integrating unit 11, wherein the value integrated by the integrating unit 11 is arm-m. In the case of the broadcast type, as shown in FIG. 4 (bar), it is output to the non-inverting end (+) of the comparator 17 configured in the comparator 15 with a value of 3 volts (V) or more.

Meanwhile. Since the reference voltage of 2 volts (V) is set to be applied to the inverting end (-) of the comparator 17 configured in the comparator 15, 3 volts (V) applied after integration through the integrating unit 11 is applied. The above value becomes a value larger than 2 volts (V) which is a reference voltage value, and the comparator 17 outputs a control signal in a "high" state.

This control signal is applied to the microcomputer 18, where the microcomputer 18 causes the PAL-M broadcast signal processing circuit to operate when the applied control signal is in the "high" state, and the applied control signal is " In the low state, the NC broadcast signal processing circuit is set to operate. Therefore, the microcomputer 18 generates an arm-M broadcast signal processing circuit by the control signal of the "high" state output from the comparator 15. Will be controlled to operate.

Accordingly, the broadcast method of the received broadcast signal is automatically checked and a signal processing circuit capable of signal processing the broadcast signal of the corresponding broadcast method is automatically switched and operated.

Finally, the broadcast method automatic switching circuit checks the phase shift of the color signal between the NTS broadcast system and the PA-M broadcast method to determine the received broadcast method, and processes the broadcast signal according to the determined broadcast method. By automatically switching to the mode, the user's convenience is enhanced, and there is an advantage of always being able to watch a stable broadcast mode.

Claims (1)

A broadcasting method automatic switching circuit for receiving a broadcast signal and an ARM-M broadcasting signal and automatically operating the broadcasting signal processing circuit according to the received broadcasting method, wherein the phase of the color signal of the received broadcasting signal is checked. The video signal processing means for outputting the auto phase control error signal according to the phase of the checked color signal and the auto phase control error signal output from the video signal processing means are amplified to a predetermined size to tune only a predetermined frequency band of the auto phase control error signal. Amplification and tuning means for outputting a predetermined voltage value according to the state of the tuned signal; an integration means for smoothing and integrating a predetermined voltage value output from the amplification and tuning means into a constant voltage value; After comparing the output constant voltage value with the reference voltage, output the control signal according to the comparison result to the microcomputer. And a comparison means for automatically operating signal processing means capable of processing the broadcast signal.