JPH07240913A - Scramble signal receiver - Google Patents

Abstract

PURPOSE:To make handling convenient by always obtaining optimum signals without any complicated operation by discriminating whether it is an information signal to which first scramble processing is executed or second scramble processing is executed and selectively leading out the information signal based on this output. CONSTITUTION:A television signal TV 1 processed by a decoder 23 is respectively supplied to a synchronizing discrimination circuit 27 and a signal selection circuit 22, the presence/absence of the signal TV 1 is discriminated by the circuit 27, and the result is outputted to a control circuit 19. On the other hand, a television signal TV 2 processed by a decoder 24 is respectively supplied to a synchronizing discrimination circuit 28 and the circuit 22 as well, the presence/absence of the signal TV 2 is discriminated by the circuit 28, and the result is outputted to the circuit 19. Concerning the operations of these circuits 27 and 28, the presence/absence of vertical synchronism is detected by separating synchronizing signals from both the inputted signals TV 1 and TV 2 and integrating these synchronizing signals at an integration circuit. Thus, one signal selected out of the television signals TV 1 and TV 2 from a demodulation circuit 20 is transmitted to a receiver 29 as the output of a satellite broadcast receiver 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for receiving pay broadcasting using a satellite, for example, and more particularly to improvement of a scrambled signal receiving apparatus for decoding a scrambled information signal to be broadcast.

[0002]

2. Description of the Related Art As is well known, a pay broadcasting system is prevailing in satellite broadcasting systems currently in use. In this pay broadcasting system, the information signal to be broadcast is scrambled so that only the viewer who pays a predetermined fee to the program supplier and subscribes to receive the program can view the program correctly. There is. Therefore, in order to receive a pay broadcast program, in addition to a normal satellite broadcast receiver, a decoder for restoring the scrambled information signal to the original information signal is required.

Further, in the pay broadcasting using the current satellite,
A television broadcasting system that targets a television signal as an information signal to be broadcast and a music broadcasting system that targets a music signal have been realized. Of these, the scramble system adopted in the television broadcasting system is divided into two types, and in order to restore the television signal scrambled by each system to the original signal,
Each requires its own decoder.

FIG. 3 shows a conventional receiving system for receiving such satellite television broadcasting. First, the radio signal transmitted from the satellite is received by the antenna 11 and frequency-converted, and then supplied to the satellite broadcast receiver 12. The satellite broadcast receiver 12 demodulates the input television modulated signal and outputs the obtained scrambled television signals STV1 and STV2 to the decoders 13 and 14, respectively.

The decoders 13 and 14 restore the respectively input scrambled television signals STV1 and STV2 to the original television signals TV1 and TV2. The restored television signals TV1 and TV2 are the satellite broadcast receiver 12 respectively. Returned to. In this case, the decoder 13,
The television signals TV1 and TV2 restored in 14 are
Although it may be considered that the television receiver 15 is directly supplied and reproduced, a system for returning to the satellite broadcast receiver 12 in consideration of the limitation of the number of input terminals of the television receiver 15 and the usability of the user. It is common to configure

Then, in the satellite broadcast receiver 12, the television signals TV1, TV1 supplied from the decoders 13, 14 are supplied.
It is possible to selectively output the TV 2 and the internal television signal that is not output to the decoders 13 and 14 and that has been subjected to signal processing in the satellite broadcast receiver 12 to the television receiver 15 as needed.

That is, an internal television signal is received when a television broadcast that has not been scrambled is received, and a television is received when a scrambled television signal STV1 that can be restored by the decoder 13 is received. The scrambled television signal STV2 which can restore the signal TV1 by the decoder 14.
The user operates the satellite broadcast receiver 12 to switch so that the television signal TV2 is selected and output to the television receiver 15 when receiving.

Here, the satellite broadcast receiver 12 is used as a signal to be output to the television receiver 15 when receiving a television broadcast that has not been scrambled.
The television signal TV which is output from the decoders 13 and 14 by selecting the internal television signal subjected to signal processing in the
The reason why the switching operation is performed so as not to select 1 and TV 2 will be described.

That is, the decoder used to restore the scrambled television signal in the current satellite television broadcasting, first, converts the input scrambled television signal into an A / D (analog / digital) signal. ) After conversion, decoding processing is performed, and the resulting decoded television signal is D / A
(Digital / analog) conversion and output method is adopted.

When a television signal that has not been scrambled is supplied to this type of decoder,
After the input television signal is A / D converted, it is D / A converted as it is and output without being subjected to decoding processing. In this case, the television signal output from the decoder is not negligible as compared with the television signal input to the decoder due to the quantization error caused by the A / D conversion and the D / A conversion. Will result in deterioration of image quality. For this reason, it is better to supply an internal television signal to the television receiver 15 without passing through the decoders 13 and 14 when receiving a television broadcast that has not been scrambled, in order to obtain high image quality. This is advantageous.

By the way, in the above-mentioned conventional satellite television broadcast receiving system, the television receiver 1 is used.
Even if 5 is replaced with a VTR (video tape recorder), the switching operation between the internal television signal and the decoded television signal is required for the same reason as above.

Recently, satellite broadcast receivers having a built-in decoder have been commercialized and are becoming popular in the market. However, for users who want to easily receive satellite broadcasts, a low-cost decoder that does not have a decoder is built in. It can be said that a general method is to build a system in which a low price satellite receiver is first purchased and then a decoder is additionally purchased. Therefore, it is considered that there are many receiving systems in which only one decoder is connected to the satellite broadcast receiver.

However, in such a receiving system, for example, by performing a channel switching operation of the satellite broadcast receiver, the reception state of the scrambled television broadcast from the reception state of the scrambled television broadcast is received. When switching to the state, or vice versa, and when switching to the reception state of the television broadcast scrambled by a scramble system different from the scramble system of the currently received television broadcast, Each time
In order to switch the television signal output to the television receiver or VTR, it is necessary to switch the satellite broadcast receiver, which causes a problem that the user is complicated and inconvenient to handle.

Further, when the decoder is not required, that is, when the television broadcast scrambled by the scramble system that can be restored by the decoder is not received, the power of the decoder is cut off to save power consumption. In consideration of such usage, it is necessary for the user to frequently perform power-on / off operation of the decoder in addition to the above switching operation, which makes the overall operation of the receiving system more complicated. That also causes the inconvenience.

[0015]

As described above, the conventional satellite television broadcast receiving system has a problem that the output switching operation in the satellite broadcast receiver is complicated and inconvenient for the user. Further, in consideration of saving the power consumption of the decoder, there is also a problem that the power-on / off operation of the decoder needs to be frequently performed, which further complicates the operation.

Therefore, the present invention has been made in consideration of the above circumstances, and it is possible to always automatically select the optimum signal without performing a complicated operation, which makes it convenient for the user to handle. An object is to provide a good scrambled signal receiving device.

Further, in addition to the above object, the present invention provides a very good scrambled signal receiving device capable of saving the power consumption of the decoder without requiring the user to turn on / off the power of the decoder. The purpose is to do.

[0018]

A scrambled signal receiving apparatus according to the present invention includes an information signal which is not scrambled, an information signal which is scrambled by a first scramble system, and a first scrambler. It is intended for a receiver of a broadcasting system in which an information signal scrambled by a second scramble system different from the system is mixed and broadcast.

Then, whether the received and selected information signal is an unscrambled information signal, a first scrambled information signal or a second scrambled information signal. Discriminating means for discriminating, signal processing means for receiving and receiving the selected information signal, signal processing means for performing signal processing on the unscrambled information signal, and receiving and receiving the selected information signal are supplied. , First decoding means for performing decoding processing on the information signal scrambled by the first scrambling method,
A second decoding means for supplying the received and selected information signal and for decoding the information signal scrambled by the second scrambling method, the output of the signal processing means and the first decoding means A selection means for selectively deriving the output of the decoding means and the output of the second decoding means based on the output of the discrimination means is provided.

Further, in the scramble signal receiving apparatus according to the present invention, in addition to the above configuration, the information signal received and tuned by the discriminating means is an information signal subjected to the first scramble processing. In the determined state, the power source power is supplied to the first decoding means, and the received and tuned information signal is determined to be the second scrambled information signal. The decoding means is provided with a power supply means for supplying power supply.

[0021]

According to the above structure, first, the output of the signal processing means for performing signal processing on the information signal not subjected to the scramble processing and the information signal subjected to the scramble processing by the first scramble system are processed. The output of the first decoding means for performing the decoding processing and the output of the second decoding means for performing the decoding processing on the information signal scrambled by the second scrambling method are received and selected. Based on the output of the discriminating means for discriminating whether the local information signal is an unscrambled information signal, a first scrambled information signal or a second scrambled information signal. Since it is derived selectively, the optimum signal can always be selected automatically without performing complicated operations, making it convenient for the user to handle. Rukoto can.

Further, when the discriminating means determines that the received and selected information signal is the information signal subjected to the first scramble processing, the power source is supplied to the first decoding means. , The power supply is supplied to the second decoding means in a state where the received and tuned information signal is determined to be the information signal subjected to the second scramble processing. Power on / decoding means
It is possible to save the power consumption of the decoding means without requiring the operation of shutting off.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 1, a radio signal transmitted from a satellite is received by an antenna 16 and frequency-converted, and then supplied to a tuning circuit 18 which is a front end of a satellite broadcast receiver 17. The tuning circuit 18 selects a specific television modulation signal under the control of the control circuit 19 and outputs the television modulation signal to the demodulation circuit 20. The demodulation circuit 20 performs FM (Frequency Modulation) demodulation of the input television modulation signal, outputs the demodulated television signal to the control code detection circuit 21 and the signal selection circuit 22, respectively, and also to the satellite broadcast receiver. Decoders 23, 24 connected to the outside of 17
Output to each.

Among them, the control code detection circuit 21 detects a scramble flag included in a part of the satellite broadcast audio signal and outputs the detection result to the control circuit 19.
That is, the form of the audio signal in satellite broadcasting is PCM.
(Pulse Code Modulation) A digital voice is combined with various control codes and data other than voice to form a frame, and a scramble flag (identification signal) for identifying whether or not the 7th bit of the control code is scrambled. ) Is assigned to. The control code detection circuit 21 detects whether the 7th bit of the control code is "1" or "0".

The decoder 23 has a power supply circuit 25.
The AC power output from the power supply circuit 25 is supplied and driven, and the power supply circuit 25 can turn on / off the output power under the control of the control circuit 19. . Further, the decoder 24 is adapted to be driven by being supplied with the AC power output from the power supply circuit 26, and this power supply circuit 26 also turns on / off its output power under the control of the control circuit 19. It can be turned off.

Next, the television signal TV1 decoded by the decoder 23 is supplied to the synchronization discrimination circuit 27 and the signal selection circuit 22, respectively. Sync discrimination circuit 27
Is a television signal TV output from the decoder 23.
The presence or absence of 1 is determined, and the determination result is output to the control circuit 19. Further, the television signal TV2 decoded by the decoder 24 is supplied to the synchronization determination circuit 28 and the signal selection circuit 22, respectively. Sync discrimination circuit 28
Also, the television signal TV output from the decoder 24
The presence or absence of 2 is discriminated and the discrimination result is output to the control circuit 19.

Then, the synchronization determination circuits 27, 2
8 is the input television signal TV
1 and TV2, a synchronizing signal is separated, and the synchronizing signal is integrated by an integrating circuit to detect the presence or absence of vertical synchronization. This can be realized by a general-purpose technique.

Under the control of the control circuit 19, the signal selection circuit 22 receives the television signal output from the demodulation circuit 20, the television signal TV1 decoded by the decoder 23, and the decoder 24 for decoding. One of the processed television signals TV2 is selected and sent to the television receiver 29 as the output of the satellite broadcast receiver 17.

Now, the operation of the control circuit 19 will be described. That is, the present satellite broadcasting is performed using three satellites, but the channel frequencies of the television modulation signals transmitted from the respective satellites are different. Therefore, the control circuit 19 stores unique channel frequency data corresponding to each satellite,
The tuning circuit 18 is controlled based on the channel frequency data.

It has been described above that there are two types of scramble systems used in satellite television broadcasting.
The same scramble system is adopted in one satellite. That is, assuming that the three satellites are A, B, and C, respectively, and the two types of scramble systems are X and Y, the scramble system X is adopted in the satellites A and B, and the scramble system Y is adopted in the satellite C. It means that

Here, assuming that the decoder 23 performs the decoding process corresponding to the scramble system X and the other decoder 24 performs the decoding process corresponding to the scramble system Y, scramble with each satellite A, B, C. The correspondence relationship between the systems X and Y and the decoders 23 and 24 is stored in the control circuit 19.

Then, the control circuit 19 controls the satellite A or B.
Is received, the power supply circuit 25 for supplying AC power to the decoder 23 is driven, and when the satellite C is received, the power supply circuit 26 for supplying AC power to the decoder 24 is driven.

Further, while the satellite A or B is being received, it is determined that the television modulation signal currently being received is scrambled, and based on the output signal of the synchronization determination circuit 27. When it is determined that the television signal TV1 is output from the decoder 23, the control circuit 19 controls the signal selection circuit 22 to select the television signal TV1 output from the decoder 23.

Further, while the satellite C is being received, it is determined that the television modulation signal currently being received has been scrambled, and the synchronization determination circuit 28
When it is determined that the television signal TV2 is output from the decoder 24 based on the output signal of, the control circuit 19 selects the television signal TV2 output from the decoder 24. Control the circuit 22.

In addition to the above two cases, the control circuit 19 controls the signal selection circuit 22 so as to select the television signal output from the demodulation circuit 20 as the internal television signal.

FIG. 2 shows a flowchart summarizing the operation of the control circuit 19 as described above. First, in step S1, the control circuit 19 determines, based on the detection result of the control code detection circuit 21, whether or not the television modulation signal currently being received has been scrambled. Then, when it is determined that the scramble process is not performed (NO), the control circuit 19 determines in step S2.
Then, the signal selection circuit 22 is controlled so as to select the television signal output from the demodulation circuit 20.

When it is determined that the scramble process is performed (YES), the control circuit 19 determines, based on the tuning instruction sent to the tuning circuit 18 in step S3.
Determine which satellite is currently receiving. Then, when it is determined that the satellite is the satellite A or B, the control circuit 19 drives the power supply circuit 25, and the step S4
Then, it is determined whether or not the television signal TV1 is output from the decoder 23 based on the determination result of the synchronization determination circuit 27.

Here, when it is determined that the television signal TV1 is not output from the decoder 23 (N
O), the control circuit 19 proceeds to the process of step S2, and controls the signal selection circuit 22 to select the television signal output from the demodulation circuit 20. Also, step S
If it is determined in 4 that the television signal TV1 is output from the decoder 23 (YES), the control circuit 19
In step S5, the signal selection circuit 22 selects the television signal TV1 output from the decoder 23.
To control.

Further, when it is determined that the satellite is the satellite C in step S3, the control circuit 19 causes the power supply circuit 26 to operate.
Is driven, and in step S6, based on the determination result of the synchronization determination circuit 28, the television signal T is output from the decoder 24.
It is determined whether or not V2 is output. When it is determined that the television signal TV2 is not output from the decoder 24 (NO), the control circuit 19 proceeds to the process of step S2 and selects the television signal output from the demodulation circuit 20. The signal selection circuit 22 is controlled. If it is determined in step S6 that the television signal TV2 is output from the decoder 24 (Y
ES), the control circuit 19 determines in step S7 that the decoder 2
The signal selection circuit 22 is controlled so as to select the television signal TV2 output from No. 4.

Therefore, according to the configuration of the above embodiment, whether or not the received television modulated signal has been scrambled, the satellite being received, the type of the scramble system, etc. are received by the satellite broadcasting. Since it is automatically determined inside the device 17 and the optimum television signal is selected and output to the television receiver 29, it is not necessary to perform a complicated switching operation, and the handling is convenient for the user. Can be Further, based on the above judgment result, the required decoders 23, 24
Since the AC power is automatically supplied only to the decoders 23 and 24, the power consumption of the decoders 23 and 24 can be saved without the need to turn on / off the decoders 23 and 24. The present invention is not limited to the above-described embodiment, and can be variously modified and implemented without departing from the scope of the invention.

[0041]

As described above in detail, according to the present invention,
It is possible to provide an extremely good scrambled signal receiving device that can always automatically select the optimum signal without performing a complicated operation and can make the handling convenient for the user.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

FIG. 3 is a block configuration diagram showing a conventional satellite television broadcast receiving system.

[Explanation of symbols]

11 ... Antenna, 12 ... Satellite receiver, 13, 14 ...
Decoder, 15 ... Television receiver, 16 ... Antenna, 17 ... Satellite broadcast receiver, 18 ... Channel selection circuit, 19 ... Control circuit, 20 ... Demodulation circuit, 21 ... Control code detection circuit, 2
2 ... Signal selection circuit, 23, 24 ... Decoder, 25, 26
... power supply circuit, 27, 28 ... synchronization determination circuit, 29 ... television receiver.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04L 9/14 H04N 7/20

Claims (4)

[Claims] 1. An information signal that is not scrambled, an information signal that is scrambled by a first scramble system, and a scramble process by a second scramble system different from the first scramble system. In a receiver of a broadcasting system that broadcasts mixed information signals, the information signal received and tuned is not scrambled or is first scrambled information. Determination means for determining whether the signal is a signal or a second scrambled information signal, and the received and tuned information signal is supplied, and signal processing is performed on the unscrambled information signal. Signal processing means and the received and selected information signal are supplied to the information signal scrambled by the first scrambling method. A first decoding means for performing a decoding process for the information signal, and a decoding process for the information signal supplied with the received and selected information signal and scrambled by the second scrambling method. 2 decoding means, and a selecting means for selectively deriving the output of the signal processing means, the output of the first decoding means, and the output of the second decoding means based on the output of the determining means. A scrambled signal receiving apparatus comprising: 2. The power supply to the first decoding means in a state in which the determining means determines that the received and selected information signal is the information signal subjected to the first scramble processing. A power supply that supplies power and supplies power to the second decoding means in a state where it is determined that the received and selected information signal is the information signal subjected to the second scramble processing. The scrambled signal receiving apparatus according to claim 1, further comprising a supplying unit. 3. The discriminating means, based on the identification data included in the received and selected information signal, the information signal is not scrambled or is scrambled. In the state where it is determined that the information signal is a scrambled information signal by the first determining means for determining whether or not the information signal is the first signal based on the selected channel. 2. The scrambled signal receiving apparatus according to claim 1, further comprising: second determining means for determining whether the scrambled information signal or the second scrambled information signal. . 4. A first discriminating means for discriminating whether or not a sync signal is detected at the output of the first decoding means, and whether or not a sync signal is detected at the output of the second decoding means. A second discriminating means for discriminating whether the information signal selected and received by the discriminating means is the information signal subjected to the first scramble processing. And the synchronization signal is detected by the first detecting means, the output of the first decoding means is selected, and the information signal received and selected by the determining means is the second signal. The output of the second decoding means is selected in a state in which it is determined that the information signal has been subjected to the scramble processing and the synchronization signal is detected by the second detecting means. Item 1. The scrambled signal receiving device according to item 1. .