KR920004510Y1 - Signal source switching circuit for satellite broadcasting tv - Google Patents

Abstract

No content.

Description

Signal source switching circuit of satellite broadcasting receiving television

1 is a signal source switching circuit diagram of a conventional TV with a built-in satellite broadcasting receiver.

2 is a mode signal source switching circuit diagram of a TV with a built-in satellite broadcasting receiver according to the present invention.

3 is a flow chart for explaining the microcomputer operation of FIG.

* Explanation of symbols for main parts of the drawings

12: TV tuner 14: TV demodulator

16: BS tuner 18: BS demodulator

20: microcomputer 22, 26, 30: first, second, third power switching unit

24, 28, 32: first, second, third mode signal source output section 34: audio output circuit

36: Video Processor

The present invention relates to mode signal switching of a television with a built-in satellite broadcasting receiver, and more particularly, to a mode signal automatic switching circuit for automatically outputting a desired video and audio signal only by selecting a channel of a desired predetermined mode.

To watch satellite broadcasts on your current television (hereinafter called TV), you must have a satellite receiver to watch.

The satellite broadcasting receiver has an external type that can be connected from the outside of the TV, and there is a built-in type built in the TV. 1 is a conventional satellite broadcast receiving circuit diagram capable of receiving satellite broadcasts, wherein a TV tuner, VIF and SIF demodulator (TV demodulator), a switch, an image and audio processor, and a first microcomputer are a general TV configuration. 2 The configuration of the microcomputer, BS (broadcasting setellite) tuner, FM demodulation and PCM demodulation (BS demodulator) is a satellite broadcasting receiver.

The AV terminal is an external signal input terminal attached to the TV.

At this time, when the satellite broadcasting receiver is in external time, the satellite broadcasting is viewed by inserting it into the jack of the AV terminal. In the case of the TV built-in type, the dotted line shown in FIG. 1 is connected.

In the configuration as shown in FIG. 1, when the key signal input to the first microcomputer is TV selection and a channel selection signal is input, the first microcomputer outputs a TV mode signal through a switch and is tuned by a TV tuner to demodulate from a TV demodulator. Video and audio signals are input to watch TV signals.

In order to watch satellite broadcasting in the above configuration, the key signal KS must be input in the video mode so that the switch can be switched to the AV terminal.

When the satellite signal selector signal is supplied to the second microcomputer by the key signal KS2, the second microcomputer outputs the BS tuning signal to the BS tuner.

At this time, the BS tuner tunes and outputs satellite broadcasting under the control of the second microcomputer, and the BS demodulator demodulates the output of the BS tuner and inputs it to the switch output.

Accordingly, the BS demodulation signal is applied to the video and audio processing unit so that the BS broadcast can be viewed.

However, the conventional configuration that is operated as described above is for watching the BS broadcast signal and in the case of the long type, the TV mode is the external video mode, and the input of the satellite broadcasting receiver is inputted, or in the case of the built-in type, the TV mode is video. It has been watched by selecting the BS channel as the input mode.

Therefore, in order to watch a BS broadcast while watching a general TV broadcast according to the above configuration, there was a inconvenience in the key operation several times.

Accordingly, an object of the present invention is to provide a circuit for reproducing a desired channel signal of a desired mode by inputting a channel selection signal of a predetermined operation mode in a television having a satellite broadcasting receiving module.

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

2 is a mode signal source switching circuit diagram according to the present invention, which searches for input of a TV tuner 12, a TV demodulator 14, a BS tuner 16, a BS demodulator 18, and a predetermined key signal C5. A microcomputer 20 for outputting a corresponding mode control signal, a first gate G1 for outputting a first mode control output of the microcomputer 20, a resistor R1, and a transistor TR1 and TR2. An image of the TV demodulator 14 is formed of a first power supply switching unit 22, resistors R2-R7, and transistors TR3 and TR4 by powering the first power switching unit 22. A first mode signal source switching unit 24 for passing signals and voice signals, a second gate G2 and a second gate G2 for gating and outputting only the second mode control signal of the microcomputer 20. A second power source switching section 26 composed of transistors TR5 (TR6) and resistors R8 that are switched by the output of the < Desc / Clms Page number 5 > A second mode signal source switching unit 28 configured to (TR7-TR8) to pass the external video signal EXVD and the audio signal EXAD by the output of the second power switching unit 26, and the microcomputer. A third power switch 30 and a resistor R16-R21 switched by the third gate G3 and the third gate G3 signal gating only the third mode control signal of the 20 to switch a predetermined power source. And a third mode signal source switching unit which is operated by a switching power supply of the third power switching unit 30 to pass video and audio signals of the BS tuner 18. 32, and an audio output circuit 34 for inputting demodulated outputs of audio signals and video signals respectively output from the first, second, and third mode signal source switching units 24, 28, and 30; And a video signal processing processor 36.

FIG. 3 is a flowchart for explaining an operation procedure of the microcomputer 20 of FIG.

An operation example of FIG. 2 according to the present invention will be described with reference to the flowchart of FIG.

If an arbitrary key signal CS (the key signal is a front key or a remote key press signal) is input to the microcomputer 20, the microcomputer 30 searches for the application of the satellite broadcasting channel selection key. . (3A course).

At this time, even when the input key signal CS is a channel selection key for satellite broadcasting, the microcomputer 20 outputs a "high"-"low" signal to the ports A and B. (3B process).

The satellite broadcasting channel selection signal (BSCHSS) for the input channel is output to the BS tuner 16. Accordingly, the BS tuner 16 tunes only the input selection channel signal among the plurality of satellite broadcast channel signals inputted to the antenna and inputs the same to the BS demodulator 1S. The BS demodulator 1S demodulates the input signal to perform satellite broadcast video signal and audio. The signal is output to the base of the transistors TR12 and TR11.

Meanwhile, the third gate G3 gates the third mode control signal " high "-" low " of the microcomputer 20 to input the " high " signal to the base of the transistors TR9 and TR10. do.

At this time, the power supply voltage B + is provided to the above-described collector terminals of the transistors TR11 and TR12, so that the satellite broadcasting audio signal and the satellite broadcasting video signal are amplified and output from the transistors TR11 and TR12.

Accordingly, the transistors TR11 and TR12 output the respective signals to the audio output circuit 34 and the video processor 36 to reproduce satellite broadcasting.

The external image input key signal CS is input to the microcomputer 20 during operation as described above, and the microcomputer 20 determines that the external video input mode is in the external video input mode (step 3C), and goes to the port A, B. High "signal is output (3D process).

Therefore, the second gate G2 is "high", and the output transistors TR5 and TR6 are turned on, which causes the transistors TR7 and TR8 to input the external video signal EXVD and the audio signal EXAD as a base. The amplified signals are respectively output from the collectors of the < RTI ID = 0.0 >) < / RTI >

If there is no mode selection, the microcomputer 20 outputs a "high-high" signal to the ports A and B (process 3E).

Accordingly, the first gate G1 of the "high" transistors TR1 and TR2 is turned on to apply a power supply voltage to the collectors of the transistors TR3 and TR4.

When the TV channel selection signal is input in the above state, the microcomputer 20 inputs the channel selection signal TCHSS to the TV tuner 12.

At this time, the TV tuner 12 tunes only a desired channel signal according to the input channel tuning signal TCHSS and inputs it to the TV demodulator 14, and the TV demodulator 14 demodulates the TV video signal and the TV audio signal. To the base of the transistors TR14 and TR13.

Accordingly, the TV audio signal and the TV video signal are amplified and output from the collectors of the transistors TR13 and TR14. As a result, the audio output circuit 34 and the video processor 36 reproduce and output the TV audio and video signals. .

When the satellite broadcasting channel selection signal is input during the operation as described above, the microcomputer 20 outputs a "high-low" signal to the output ports A and B as described above, thereby operating the transistors TR11 and TR12. Only satellite broadcasting audio signals and video signals are passed to the reproduction circuit for reproduction.

As described above, the present invention can easily operate the receiving system having the satellite broadcasting receiver by switching the mode signal source by the mode control signal.

Claims (1)

TV tuner 12, TV demodulator 14, BS tuner 16, BS demodulator 18 having audio output circuit 34 and video processor 36 for processing and outputting audio and video signals. In a signal source switching circuit of a satellite broadcasting reception television, a microcomputer inputs a channel selection signal to the TV tuner 12 or the BS tuner 16 by a mode selection signal key and a channel selection key signal input and outputs a mode control signal. And a first power switching circuit 22 which is switched by a first mode control signal output of the microcomputer 20 to output a predetermined voltage, and a switching voltage output of the first power switching circuit 22. A first mode signal source switching circuit 24 which is operated by to pass the audio and video signals of the TV tuner 12 to the audio output circuit 34 and the video processor 36; A second electric switch switched by the second mode control signal to output a predetermined voltage; A second mode in which switching is performed by the switching circuit 26 and the output of the second power switching circuit 26 to pass external video signals and audio signals to the audio output circuit 34 and the video processor 36, respectively. A signal source switching circuit 28, a third power switching circuit 30 that is switched by a third mode control signal of the microcomputer 20 to output a predetermined voltage, and audio and video signals of the BS demodulator 18; And a third mode signal source switching circuit 32 which is switched by the output of the third power switching circuit 30 and passed to the audio output circuit 34 and the video processor 36, respectively. Circuit.