KR950005408Y1 - Auto fine tunring signal dealing circuit - Google Patents

Abstract

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Description

Image and auto-tuning signal processing circuit according to broadcasting method

1 is an image and automatic untuned signal processing circuit diagram of the present invention.

2 is an output waveform diagram of each part of FIG.

3 is an explanatory diagram showing an operation relationship according to the broadcasting method of FIG. 1, wherein a table of changes of automatic untuned signals and video signals.

* Explanation of symbols for main parts of the drawings

10: Tuner part for SECAM-L method 14, 24: Middle frequency shear amplifier

15, 25: surface acoustic wave filter 20: tuner unit for PAL-B / G method

31: Image intermediate frequency amplifier 32: Image detector

33: automatic non-tuning section 34: operational amplifier section

35, 38: inverted amplifier 36, 37, 41, 42: switching unit

39, 40: buffer portion

The present invention relates to an image and an automatic untuned signal processing circuit of a television receiver, and in particular, to convert a video signal and an automatic untuned (AFT) signal according to the SECAM-L method and the arm (PAL-B / G) method. The present invention relates to an image and an automatic untuned signal processing circuit according to a broadcasting method that can be output.

In general, the Secam method adopts the positive modulation method, the arm method adopts the sub modulation method, and the frequencies of both broadcast signals are different. Also, the tuner local oscillation method uses the VHF low band and the VHF. According to the high band and the UHF band, the upper heterodyne method and the lower heterodyne method are employed, respectively, and the upper heterodyne method is adopted for the arm method regardless of each channel band.

In this way, the received broadcast signals are different according to the Secam method and the arm method, and the tuner local oscillation methods are different from each other. Therefore, the video signals processed by both broadcast methods are different from each other and the auto-tuned signals used in the automatic search are also different. Accordingly, the Secam television receiver can receive only the Secam broadcast signal and process the video signal and the auto-tuning signal, and the arm television receiver receives only the arm broadcast signal to receive the video signal. And there was a drawback that can process the auto fine signal.

Accordingly, an object of the present invention is to provide a broadcast signal capable of receiving a Secam method and an arm signal, and processing the video signal and the auto-tuning signal according to the selection of the Secam method and the arm method. The present invention provides an image and automatic tuning signal processing circuit.

The purpose of the present invention is to provide a SECAM-L type tuner and a PAL-B / G type tuner for receiving Secam and arm broadcast signals, and two amplifying output signals for both tuner portions. Two surface acoustic wave filters for surface acoustic wave (SAW) filtering the output signals of the intermediate frequency shear amplifier and both intermediate frequency amplifiers, and Secam / arm for selecting the output signals of the surface acoustic wave filters by secam / arm selection signals. A selection switch, an image intermediate frequency amplifier for amplifying the signal selected by the secam / arm selection switch, an image detector for detecting an image signal from the output signal thereof, an inverting amplifier for inverting and amplifying the image signal of the image detector and its output A buffer unit for buffering the signal again, a buffer unit for buffering the video signal of the image detector, an output signal of the buffer unit, or an output signal of the inverting amplifier unit Are two switching units for respectively selecting and outputting the output signal of the buffer unit by the Secam / arm selection signal, an automatic untuning unit for outputting an auto-tuning signal by phase-modulating the output signal of the image detector; An operational amplifier for non-inverting and amplifying the output signal, an inverting amplifier for inverting and amplifying the output signal again, and two switching sections for respectively selecting and outputting the output signals of the amplifying and inverting amplifiers according to a local oscillation selection signal. It will be achieved by, when described in detail with reference to the accompanying drawings as follows.

1 is an image and automatic untuned signal processing circuit diagram according to the broadcast method of the present invention, as shown in the SECAM-L tuner unit 10 for receiving and tuning a Secam method of a broadcast signal, A tuner unit 20 for receiving and tuning broadcast signals, an intermediate frequency shear amplifier 14, 24 for amplifying the output signals of the tuner units 10, 20, The surface acoustic wave (SAW) filters 15 and 25 for filtering the output signals of the intermediate frequency shear amplifiers 14 and 24, and the output signals of the surface acoustic wave filters 15 and 25, A Secam / arm selection switch SW1 for selecting and outputting according to the arm selection signal CSO, an image intermediate frequency amplifier 31 for amplifying the image intermediate frequency from the signal output from the Secam / arm selection switch SW1, and An image detector 32 which detects and outputs an image signal from the output signal of the image intermediate frequency amplifier 31, and an output signal of the image detector 32. An auto-tuning unit 33 for phase-modulating and outputting an auto-tuning signal, an arithmetic amplifier 34 for non-inverting and amplifying the output signal of the auto-tuning unit 33, and an output signal of the arithmetic amplifier 34; Selects the output signals of the operational amplifier 34 and the inverted amplifier 35 in accordance with a local oscillation method selection signal applied to the control terminal CS1. Switching units 36 and 37 for outputting to the coarse signal output terminal A, an inverting amplifier 38 for inverting and amplifying the video signal of the video detector 32, and the video signal of the video detector 32; A buffer unit 39 for buffering the signal, a buffer unit 40 for buffering the output signal of the inverted amplifier unit 38, and the buffer unit 39 according to the Secam / arm selection signal applied to the control terminal CS2. ) And (40), each of which is composed of switching units (41) and (42) for outputting the video signal output terminal (V). (SW1) is short-circuited to its Secam selection terminal (S) when the Secam / arm selection signal (CSO) is input to its control terminal at a high potential as the Secam selection signal, and the Secam / arm selection signal (CSO) is the arm selection signal. When input to the low potential is short-circuited to its arm selection terminal (P), the high potential signal is applied to the control terminal (CS1) when the local oscillation method is the upper heterodyne system and the low potential when the lower heterodyne system A signal is to be applied, and the control terminal CS1 is short-circuited to its arm selection terminal P when the local oscillation method is a higher heterodyne method, and the control terminal CS2 has a high frequency when the Secam method is selected. When the stomach is applied and arm type selection, the low potential is to be applied.

Referring to the effect of the present invention configured in this way in detail as follows.

When the Secam method broadcast signal is received by the SECAM-L method tuner unit 10 through the antenna ANT1, the broadcast signal is amplified by the high frequency amplifier 11 and then transmitted to the local oscillator 12 and the mixer 13. The frequency is converted so that the intermediate frequency of the broadcast signal is detected.

As such, the signal detected and output by the SECAM-L type tuner unit 10 is amplified by the intermediate frequency shear amplifier 14 and then filtered by the surface acoustic wave filter 15 serving as a broadband filter. Is applied to the Secam selection terminal (S).

Similarly, when an arm type broadcast signal is received by the PAL-B / G type tuner unit 20 through the antenna ANT2, an intermediate frequency of the broadcast signal is transmitted by the PAL-B / G type tuner unit 20. After received and tuned, it is amplified by the intermediate frequency shear amplifier 24, filtered by the surface acoustic wave filter 25, and applied to the arm select terminal P of the Secam / arm selector switch SW1. At this time, if the Secam / arm selection signal CSO is a high potential state that is a Secam selection signal, the Secam / arm selection switch SW1 is short-circuited to its Secam selection terminal S, and accordingly applied to the Secam selection terminal S. The Secam method of the Secam method is selected through the Secam / arm selection switch SW1 and amplified by the image intermediate frequency amplifier 31 and then applied to the image detector 32. The video signal is detected and output.

On the other hand, if the Secam / arm selection signal CSO is a low potential state that is an arm selection signal, the Secam / arm selection switch SW1 is short-circuited to its arm selection terminal P, and accordingly applied to the arm selection terminal P. The intermediate frequency signal of the arm method is selected through the Secam / arm selection switch SW1 and amplified by the image intermediate frequency amplifier 31 and then applied to the image detector 32. The video signal is detected and output.

However, since the Secam broadcast signal is a positively modulated signal and the arm broadcast signal is a submodulated signal, the video signal of the arm method output from the image detector 32 is equal to the second c diagram, and the image detector The Secam system video signal outputted at 32 becomes like the 2d diagram.

Therefore, at this time, if the Secam method is selected as described above and the high potential, which is the Secam selection signal, is applied to the control terminal CS2, the high potential signal is applied to the transistor Q9 base side of the switching unit 41, and the transistor is applied. Since (Q9) is conducted, a low potential is output to the collector thereof to turn off the field effect transistor (FET4).

At this time, the high potential signal applied to the control terminal CS2 is applied to the base of the transistor Q6 of the switching unit 42 to conduct the transistor Q6, so that the low potential is output to the collector thereof so that the transistor Q7 ) Is turned off, and accordingly, a high potential is output to the collector of the transistor Q7 to conduct the field effect transistor FET3. Therefore, at this time, the video signal of the Secam method output from the image detector 32 as shown in FIG. 2D is inverted and amplified by the inverting amplifier 38, and the buffer unit for matching the impedance of the input and output video signals ( After buffering at 40, the signal is output to the image signal output terminal V through the capacitor C3 of the switching unit 42 and the conducted field effect transistor FET3.

On the other hand, when the arm type is selected and the low potential signal, which is the arm signal, is applied to the control terminal CS2, the low potential signal is applied to the base side of the transistor Q9 of the switching unit 41 and the transistor Q9. By turning off, the high potential signal is outputted to its collector, and the high potential signal conducts the field effect transistor FET4. At this time, the low potential signal applied to the control terminal CS2 is applied to the base of the transistor Q6 of the switching unit 42 to turn off the transistor Q6, so that a high potential signal is output to the collector thereof. Since the high potential signal conducts the transistor Q7, the low potential signal is output to the collector thereof, and the field effect transistor FET3 is turned off.

Accordingly, at this time, the arm type video signal output from the image detector 32 as shown in FIG. 2C is buffered in the buffer unit 39 matching the impedance of the input and output image signals, and then the switching unit 41. Is output to the video signal output terminal (V) through the capacitor (C5) and the conducted field effect transistor (FET4).

As a result, the waveform of the video signal output to the video signal output terminal V becomes the same regardless of the Secam method and the arm method.

On the other hand, the auto-tuning unit 33 modulates the output signal of the image detector 32 to output the auto-tuning signal. By the way, in the arm method, the upper heterodyne method is adopted regardless of each band in the local oscillation method, and in the Secam method, the upper heterodyne method is adopted in the local oscillation method in the VHF low band. In the case of the multi-function system, the auto-tuning unit 33 outputs an auto-tuning signal having a waveform as shown in FIG. 2A. In the Secam VHF high band and the UHF band, the lower oscillation method is adopted as the local oscillation method. In this case, when the local oscillation method is the lower heterodyne method, the automatic tuning unit 33 is shown in FIG. The auto-tuning signal of the waveform as shown is output.

The automatic untuned signal output as described above is non-inverted and amplified by the operational amplifier 34 and applied to the field effect transistor FET2 drain of the switching unit 36, and the output signal of the operational amplifier 34 is inverted. It is inverted and amplified again at 35 and applied to the field effect transistor FET1 drain of the switching unit 37.

Therefore, when a high potential signal is applied to the control terminal CS1 by selecting the Secam VHF low band or the arm method, in which the higher heterodyne method is employed, the high potential signal is transmitted to the transistor Q1 of the switching unit 37. The low potential signal is outputted to its collector to turn off the field effect transistor (FET1). At this time, the high potential signal applied to the control terminal CS1 is applied to the base of the transistor Q2 of the switching unit 36 to conduct the transistor Q2, so that a low potential signal is output to the collector thereof. Since the low potential signal turns off the transistor Q3, a high potential signal is output to the collector thereof to conduct the field effect transistor FET2. Accordingly, at this time, the auto-tuning signal output from the auto-tuning unit 33 as shown in FIG. ) Is output to the auto-tuning signal output terminal (A).

In addition, when the Secam VHF high band and the UHF band employing the lower heterodyne method are selected, and a low potential signal is applied to the control terminal CS1, the low potential signal is transmitted to the transistor Q1 of the switching unit 37. Since the high potential signal is output to the collector of the transistor Q1 to conduct the field effect transistor FET1, the low potential signal applied to the control terminal CS1 is the transistor of the switching unit 36. By turning off Q2), a high potential signal is outputted to its collector, and this high potential signal conducts transistor Q3, so that a low potential signal is outputted to its collector to turn off the field effect transistor FET2. Accordingly, at this time, the auto-tuning signal output from the auto-tuning unit 33 as shown in FIG. 2B is non-inverted and amplified by the operational amplifier 34 and inverted and amplified again by the inversion amplifier 35 before the conduction. Through the field effect transistor (FET1) of the switching unit 37 is output to the automatic fine tuning signal output terminal (A). As a result, the auto-tuning signal output to the auto-tuning signal output terminal A is output in the same form regardless of the local oscillation method.

When the above description is shown in a table, it is like 3rd degree.

As described in detail above, the present invention receives the Secam method and the Arm method and receives the Secam method and the Arm signal according to the selection of the Secam method and the arm method. The automatic untuned signal is outputted in the same form regardless of the tuner local oscillation method. Accordingly, it is possible to receive and process the broadcast signals of the Secam method and the arm method by one system.

Claims (1)

SECAM-L and PAL-B / G system tuners 10 and 20 for receiving and tuning secam and arm broadcast signals, respectively, and outputs of the tuners 10 and 20. Surface acoustic wave (SAW) filters (15) and (25) for filtering the output signals of the intermediate frequency amplifiers (14) and (24) for amplifying the signals, and the output signals of the intermediate frequency amplifiers (14) and (24), Secam / arm selection switch (SW1) for selecting and outputting the output signals of the surface acoustic wave filters (15) and (25) according to the Secam / arm selection signal, and a signal selected and output from the Secam / arm selection switch (SW1). Phase-modulated image detector 32, which detects and outputs an image signal from the output signal of the image intermediate frequency amplifier 31 and the image intermediate frequency amplifier 31 that amplifies the signal, and output signal of the image detector 32. An automatic tuning unit 33 for outputting an automatic tuning signal, an operational amplifier unit 34 for non-inverting and amplifying the automatic tuning signal, and the operation amplifier unit 3 Inverting amplification unit 35 for inverting and amplifying the output signal of 4) and output signals of the operational amplifier 34 and inverting amplifying unit 35 are respectively selected according to the local oscillation method selection signal and output as an automatic untuned signal. Switching sections 36 and 37, an inverting amplifier 38 for inverting and amplifying the video signal of the image detector 32, and a buffer unit 39 for buffering the video signal of the video detector 32; And a buffer unit 40 for buffering the output signal of the inverting and amplifying unit 38 and an output signal of the buffer units 39 and 40 according to the Secam / arm selection signal, respectively, and outputting them as video signals. A video and auto-tuning signal processing circuit according to the broadcasting method, characterized in that it comprises a switching unit (41), (42).