KR20000033624A - Method for erasing scrambled channel in auto-search operation of broadcasting signal receiver - Google Patents

Abstract

PURPOSE: A method for erasing a scrambled channel in an auto-search operation of a broadcasting signal receiver is provided. CONSTITUTION: A method for erasing a scrambled channel in an auto-search operation of a broadcasting signal receiver comprises the steps of sequentially searching all channel bands, and confirming whether the number of synchronous signals searched in each channel band reaches into a predetermined number, when a first auto-search operation starts under the control of a TV or VCR microcomputer; performing a window search and confirming whether the window is detected, when the number of the searched synchronous signals reaches into the predetermined number; recording a selected local oscillation frequency(f), when the window is detected; confirming whether a second auto-search operation is selected by a remote controller control signal, and sequentially outputting the channel data searched in the first auto-search operation, when the first auto-search operation is finished; and A/D converting video signals of each channel, judging the video signals as scrambled broadcasting signals and skipping the searched channel when the level of the video signals is over 0.8V, and memorizing the selected local oscillation frequency(f) when it is below 0.8V. As a result, a tuner of a TMI module unit in the TV or VCR is prevented from memorizing the scrambled broadcasting channel.

Description

How to delete scrambled channel during auto search of broadcasting signal receiver

The present invention relates to a method for deleting a scrambled channel during auto search of a broadcast signal receiver, and more particularly, when a cable broadcast line is connected but receives a broadcast signal through a TV or VCR tutor without a converter. A method for erasing the scrambled channel on when a search signal catches a number of invisible scrambled channels, which automatically deletes these channels when the second auto search is performed. auto-searching of broadcasting signal receiver).

On the receiving side of a conventional TV or VCR, a tuner unit for tuning a broadcast video signal coming from an antenna according to a user's selection, and an IF (Intermediate Frequency) signal are obtained by frequency converting the video signal of the tuned tuner unit. The amplification unit is divided into an IF amplifying unit, and the tuner unit includes an RF amplifier, a mixer, and a local oscillator.

The frequency band of the video signal through the tuner may be classified into an image IF (PIF), an audio IF (SIF), and a color carrier (CSCW) as shown in FIG. 1, and a normal image is obtained only when they are amplified to the displayed level.

As shown in FIG. 1, the level of the image IF is located at -6 dB, and the audio IF has a bit of 920 Hz between the audio IF and the color carrier to affect the screen. Attenuation is as follows.

Fig. 2 is a block diagram showing a receiving unit of a conventional TV or VCR, wherein a key matrix unit 1 for outputting a key input signal selected by a user and a pulse signal by the output signal of the key matrix unit 1 are shown. A control unit 2 for outputting a signal, a pulse width modulation unit 3 for outputting a pulse width modulation signal having a predetermined level value by the output signal of the control unit 2, an amplifier 4a, and an integrator 4b. A phase adjusting and amplifying the output signal of the pulse width modulation section 3, and outputting the integrated signal a predetermined number of times, the power supply circuit 5a and the regulator 5b. A power supply unit 5 for applying a constant voltage signal having a predetermined size to the tuning controller 4 and a broadcast video signal input through the antenna ANT by an output signal of the tuning controller 4. A tuner unit 6 for tuning and outputting a desired broadcasting channel, and an amplifier 7 A), a detector 7B, an intermediate frequency detection IC 7c, and an LC resonator 7d, and an IF amplifier 7 for detecting, amplifying and outputting only an image signal among the output signals of the tuner unit 6; ) And a frequency controller 8 which outputs to the tuner unit 6 and the control unit 2 a frequency signal of a predetermined level value preset by the output signals of the control unit 2 and the IF amplification unit 7. .

A description of the operation of the prior art configured as described above is made as follows with reference to FIGS.

While the broadcast video signal through the antenna ANT is being input to the tuner unit 6, the power signal provided from the power supply circuit 5a of the power supply unit 5 passes through the regulator 5b, and FIG. A constant voltage signal of 33 V, such as), is input to the amplifier of the tuning controller 4.

In addition, at this time, the tuning selection signal by the user is input to the amplifier 4a of the tuning controller 4 through the key matrix unit 1 as shown in FIG.

The modulated pulse signal applied to the amplifier 4a becomes an amplified pulse inverted in phase as shown in FIG. 3 (d) as the width thereof changes, and then has a variation range of 0V to 33V while passing through the integrator 4b. The smoothed voltage without (Ripple) component is applied to the tuner part 6.

3 (d) shows a state in which the integrator 4b is integrated in one stage, and FIG. 3 (e) shows a state in which two stages are integrated.

In addition, the intermediate frequency detection IC 7c of the IF amplifier 7 detects only the video signal tuned by the tuner 6, and when the high level synchronization signal SYNC is detected, the automatic frequency control signal 8 is detected. Informs it to the control unit 2 through.

The control unit 2 waits for the frequency control signal AFC ± by reducing the change in the modulated pulse width. That is, when the intermediate frequency signal detected by the IF amplifier 7 enters through the frequency control terminal FC of the control unit 2 through the frequency control unit 8, the output signal of the pulse output terminal PWM is controlled and pulsed. The change of the width modulation is stopped, and the TV receives a video signal of a desired frequency band as shown in FIG.

In this case, the point P of FIG. 4 (b) is a tuning point, and the tuner 6 performs a frequency band switching and tuning in a preset mode in order to accurately perform a tuning operation. In normal mode, after tuning, the automatic frequency control signal (AFT ±) is operated to detect the phase difference of the image IF caused by the change of the local oscillator provided in the tuner unit 6 to detect the phase of the DC and generate the local oscillation frequency. It should always be kept constant.

In addition, in the intermediate frequency detection IC 7c, LC resonance is performed through the LC resonator 7d in order to match the frequency of the local oscillator provided in the tuner section 6, and this is performed through the frequency control section 8 through FIG. An automatic frequency control signal such as C) is applied to the control unit 2 and the tuner unit 6.

Accordingly, the user notifies the control unit 2 of the signal indicating the normal mode through the key matrix unit 1 and transmits the frequency control signal set by the frequency control unit 8 by the frequency control signal of the control unit 2 to the tuner unit 6. In this case, the broadcast signal of the desired channel is tuned and output.

However, conventionally, when auto-searching the tuner of a TV or a VCR, if a video synchronization signal is detected whether the user wants or not, the channel is stored in all channels such as a weak field broadcast signal or a scrambled broadcast signal.

In this case, there is a problem that the user has to manually set manually to delete the weak electric field or the scrambled channel that cannot be viewed from the memory of the microcomputer.

The present invention is to solve the above problems, the cable broadcast line is connected, but when receiving a broadcast signal to the TV or VCR tutor without a converter, a plurality of scrambled channels are not visible in the first auto search It is an object of the present invention to provide a method for deleting scrambled channels during auto search of a broadcast signal receiver that automatically deletes these channels when performing a second auto search.

As a technical idea for achieving the object of the present invention, when the first auto search is started, the process of sequentially searching the entire channel band and checking whether the number of detected synchronization signals for each channel band is a certain number, and the above confirmation As a result, when the number of searched synchronization signals for each channel band reaches a certain number, a process of checking whether a window is detected by window searching and recording the local oscillation frequency f selected when the window is detected as a result of the above check And after the first auto search is completed, checking whether the second auto search is selected by the remote controller, and sequentially reading the channel data searched by the first auto search from the memory means, and sequentially reading each other. The scrambled broadcasting channel when the level of the A / D converted video signal after the A / D conversion of the video signal of the channel becomes higher than a certain voltage. According to the present invention, it is possible to skip the searched channel and determine that the selected local oscillation frequency f is stored as it is.

1 is an explanatory diagram of frequency characteristics of a conventional TV or VCR,

2 is a block diagram illustrating a receiver of a conventional TV or VCR;

3 and 4 is a waveform diagram according to an embodiment in FIG.

5 is a block diagram illustrating a VCR system for implementing the present invention;

6 is a flowchart showing an embodiment according to the present invention.

<Description of the code | symbol about the principal part of drawing>

10 antenna 11: TMI module

12: microcomputer 13: video signal processing unit

14: A / D converter 15: CRT unit

16: memory unit 17: OSD processing unit

18: deck

Hereinafter, with reference to the accompanying drawings, the configuration and operation of the embodiment for achieving the above object will be described.

5 is a VCR system block diagram illustrating an embodiment for implementing a method for deleting a scrambled channel during auto search according to the present invention.

The system block diagram is a TMI module unit 11 consisting of a tuner, a modulator, and an IF processing unit for receiving a regular broadcast signal from the antenna 10 and performing channel tuning, and the intermediate frequency processing from the TMI module unit 11. A video signal processor 13 for receiving a video signal and processing the signal, an A / D converter 14 for A / D converting a video signal of a channel selected sequentially, and an A / D converter from the A / D converter 14. The microcomputer 12 determines whether the A / D-converted video signal is above a predetermined level by receiving the video signal of each D-converted channel, and determines whether or not there is scramble of each broadcasting channel, and under the control of the microcomputer 12. A deck unit 18 for executing a recording and playback mode, an OSD processor 17 for outputting an OSD screen under the control of the microcomputer 12, and a memory for storing predetermined information under the control of the microcomputer 12 Section 16 and the video signal processing. And a CRT unit 15 for displaying the video signal processed by the unit 13 on the screen.

A process of the present invention implemented by the system configured as described above will be described with reference to the flowchart of FIG. 6.

When a broadcast signal transmitted from a broadcasting station is applied to a TMI (Tuner / Modulator / IF Processing Unit) module unit 11 of a TV or VCR, each channel for which a video synchronization signal is detected in all channel bands is automatically tuned and tuned. Auto search for storing the channel in the memory section 16 is performed.

Referring to the VCR system as an embodiment, first, when a broadcast signal is received by the antenna 10 and input to the TMI module unit 11 of the VCR, and the first auto search is started, the microcomputer 12 checks this and then sequentially Then, all channel bands (channels 02 to 69) are searched for (S100, S101).

At this time, the microcomputer 12 periodically checks whether the channel search is completed. If the channel search is in progress, the microcomputer 12 determines whether the number of video synchronization signals of each searched channel band is 60 ± 5 and the number of synchronization signals is 60 ± 5. If the number is satisfied, the OSD signal is sent to the OSD processor 17 to further refine the display to display the OSD screen on the CRT unit 15 asking whether the window search for searching the video synchronization signal is executed (S102, S103).

However, if it is determined that the number of searched video sync signals in each channel band is not 60 ± 5, the video sync signal search is performed again (S105).

At this time, when the user selects the window search by operating the remote controller, the window search for detecting the video synchronization signal by subdividing each channel selected by the control of the microcomputer 12 is performed. When it is determined that the video synchronization signal is detected and the window is detected, the local oscillation frequency f selected accordingly is recorded and stored in the memory unit 16 (S106 and S107).

Meanwhile, when the microcomputer 12 performs the first auto search process as described above and determines that the channel search is completed, the microcomputer 12 sends a control signal to the OSD processor 17 to ask the OSD screen to select whether to select the second auto search. The display is displayed at 15 (S108).

At this time, when the user selects the second auto search by operating the remote controller, the microcomputer 12 sequentially reads the channel data searched by the first auto search from the memory unit 16 (109). In the tuner (11), the corresponding channel read sequentially is tuned, and then the broadcast signal of the channel is transmitted to the video signal processing unit 13 through the modulator and the IF processing unit.

The video signal of each channel signal processed through the video signal processor 13 is converted into an analog signal to a digital signal through an A / D converter 14 and then applied to the microcomputer 12. In this case, the microcomputer 12 In operation S110 and S111, it is determined whether the video signal level of each A / D converted channel is 0.8V or more.

As a result of the determination, when it is determined that the video signal level of each A / D converted channel is 0.8V or more, the microcomputer 12 determines that the corresponding broadcast channel is the scrambled broadcast channel and skips it (S112). If it is determined that the video signal level of each of the / D-converted channels is less than 0.8 V, it is determined to be a normal broadcasting channel, and the local oscillation frequency f selected by the first auto search is stored in the memory unit 16 as such.

As can be seen from the above description, the present invention sequentially starts when the first auto search is started in the tuner of the TMI module unit 11 by the control of the microcomputer 12 provided in a broadcast signal receiver such as a TV or a VCR. After searching all channel bands, checking whether the number of searched synchronization signals for each channel band is a certain number. If the number of searched synchronization signals for each channel band is a certain number, window search is performed. Is checked; if the window is detected, the selected local oscillation frequency f is recorded; and if the first auto search is completed, the second auto search is selected by a remote control control signal. Process of sequentially outputting each channel data searched by the 1st auto search and checking the video scene of each channel sequentially output. After A / D conversion, if the level of the A / D converted video signal is 0.8V or more, it is determined that the scrambled broadcast signal is skipped, and if it is less than 0.8V, the tuned local oscillation frequency f is reduced. By performing the process of storing as it is, there is an effect of preventing the broadcast channel that is scrambled and cannot be viewed as it is received by the tuner provided in the TMI module unit 11 of the TV or VCR as it is.

In addition, the present invention provides user convenience so that when the scrambled broadcast channel is auto searched and received and stored, the user does not need to manually delete the corresponding channel manually by operating the remote controller.

Claims (2)

In the broadcast signal receiver for auto-searching the channel band sequentially by the user's selection when the broadcast signal is received in the tuner, (a) when the first auto search is started, searching the entire channel bands sequentially and checking whether the number of detected synchronization signals for each channel band is a predetermined number; (b) in the step (a), if the number of sync signals searched for each channel band reaches a predetermined number, checking whether a window is detected by performing a window search; (c) in step (b), recording the tuned local oscillation frequency (f) when the window is detected; (d) when the first auto search is completed in step (c), checking whether the second auto search is selected by the remote controller, and sequentially reading the channel data searched by the first auto search from the memory means; (e) A / D-converting the video signal of each channel read sequentially, and if the level of the A / D-converted video signal is higher than or equal to a certain voltage, it is determined as a scrambled broadcasting channel and skips the searched corresponding channel. And a step of storing the tuned local oscillation frequency (f) as it is when the voltage is lower than the scrambled channel during auto search of the broadcast signal receiver. 2. The method of claim 1, wherein after integrating the video signal of each channel sequentially read from the memory means as a result of the first auto search in step (c), the scrambled data is scrambled when the level of the integrated video signal becomes higher than a predetermined voltage. Deleting the scrambled channel during auto-search of the broadcast signal receiver further comprises the step of skipping the searched channel determined to be a broadcast channel and storing the tuned local oscillation frequency (f) as it is when it is less than a predetermined voltage. Way.