JPS61141291A - Television set - Google Patents

Abstract

PURPOSE:To improve security on management by providing a deciding means to decide coincidence between a memory code of the channel desired channel selection or of the subscribed-channel transmitted previously and the channel number code of a transmitting TV signal of transmission line. CONSTITUTION:In a non-volatile memory 28 in a converter 19 at the terminal, the subscribed channel that was transmitted previously by a line controller 8 of the central station is stored. The subscriber inputs the desired channel to an addressable control unit 28 by a keyboard 26 or a remotecontrolling transmitter 30. If this selected channel and the stored channel of subscription coincide with each other, the selecting operation is started. Afterwards, a microcomputer 28a decides as to whether or not the channel-number code signal in the received TV signal coincides with the desired channel or with the stored channel of subscription; when judged that they are coinciding, the transmission is continued, however, when not coinciding, the operation of a channel selector is made stop, or otherwise, a specific channel is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a television system in which a center and a terminal are connected by a transmission line.

In the conventional technology 0ATVS/system, there is a cable connecting the center and the terminal converter, and in a system where the converter can see only the channels that have been applied for in advance, the channel number code is added to the television signal sent to this transmission line. If the subscriber is not subscribed to only one first channel with a cable, the subscriber must attach a frequency converter between the cable and the converter and send it from the center. By converting the channel to the first channel, programs on channels for which no subscription has been made can be viewed for free, and management security is reduced.

Problems to be Solved by the Invention Therefore, with the above configuration, eavesdropping is easily possible, so in practice, it is necessary to distinguish between the different channel numbers being transmitted and to receive programs on channels to which you do not have a contract. It is desirable to prevent this from happening.

In view of the above-mentioned problems, the present invention provides a television device that is equipped with a channel number discrimination function to improve management security.

Means for Solving the Problems In order to solve the above problems, the present invention provides a transmission line such as the above cable, and a television signal supplied to the transmission line is a video signal supplied from a center to a terminal. A channel number code signal for channel identification is inserted and transmitted adjacent to the horizontal synchronization signal immediately after the vertical retrace period, while the terminal transmits the desired channel number or the contract sent in advance when selecting a channel. Means is provided for determining whether the channel storage code matches the channel number code of the television signal transmitted over the transmission line.

Operation The present invention uses the configuration described above to determine whether or not the desired channel selection or the contracted channel storage code signal sent in advance from the center matches the channel number code. The channel selection operation is continued as is, and if there is no match, the channel selection is not performed, which can improve management security.

Example
1 Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows the overall configuration of an 0ATV device to which a television device according to an embodiment of the present invention is applied. First, the overall configuration will be explained using this diagram.

In the figure, 1 is an antenna and 2 is a retransmission device, where the RF television silane signal undergoes processing such as amplification and enters the mixer 3. 4 is another signal source, in which the output signal of the SHF receiver 4a is detected into a baseband video signal by the demodulator 6, and the output video signals from the video tape recorder 4b and the video camera 4C are directly sent to the scrambler 6. The signal is then scrambled and converted into an RF television signal by a modulator 7, which then enters the mixer 3. A line controller 8 controls the scrambling mode. The line controller 8 includes a squirrel puller controller 91L, a communication control unit 9, a microcomputer 9, a memory 1o, a display device 11, and a keyboard 12.

For example, 30 types of scramble codes are stored in the memory 1o, and any one scramble code is selected and supplied to the scrambler 6 by the scrambler controller e&, and the scrambler 6 responds to the scramble code. The system is configured to perform scrambling processing on the video signal. At the same time, the scrambler code is also supplied to the modem 13 by the communication control unit 9b, where it modulates a carrier wave of, for example, 73M2 and sends it through the mixer 3 to the terminal. The scrambler 6 sends the scrambled video signal and audio signal as well as timing information for decoding the scrambled signal.

Reference numeral 14 denotes a central control device for controlling the line controllers 8, and is installed in one facility for the line controller 8 of facility 1o, for example. 16. A modem 16 connects the microcomputer 9 and the central control unit 14. The above is the center side.

Further, 17 is a main amplifier connected to the output end of the mixer 3 through a transmission line 18 such as a coaxial cable. For example, the mixer 3 outputs a television signal of channel 6o.

Next, the terminal side will be explained. The terminal side is equipped with a channel selection device for selecting a specific television signal and a means for decoding the scrambling code as well as timing information and discrepairing the video signal that has been scrambled at the center. The converter 19 includes a converter 19, and a television receiver 2o. The converter 19 is an RF
A tuner 21 to which a television signal is input, and a demodulator 22 for demodulating an intermediate frequency signal from the tuner 21.
, Discrambler-23, and Discrambler-2
A modulator 24 for converting the output video signal and audio signal from 3 into high frequency television signals of a specific channel, a PLL synthesizer type channel selection device 25 including a microcomputer, a channel selection button, a power on/off switch, and a PLL synthesizer type channel selection device 25 including a microcomputer. Off button.

A keyboard 26 equipped with a volume control button, a reception channel number display 27, and an addressable control unit 28 that includes a non-volatile memory and a microcomputer for storing the scramble code sent from the center. , and a modem 29.

Furthermore, in order to enable remote control here, a remote control transmitter 30. A receiver 31 is provided respectively.

A scramble code sent from the center by a data carrier is demodulated via the modem 29 and written into the non-volatile memory.

Meanwhile, the timing information sent by the RF television signal is separated from the video signal by the demodulator 22 and sent to the microcomputer from the descrambler 23, which begins to decode the souffrane 7'' A/ code. The video signal is descrambled based on the code so that a normal image is displayed on the television receiver 2o.

In this example, the subscriber informs the center of the channel he/she wishes to subscribe to and writes it into the above-mentioned non-volatile memory of the terminal through the center. When selecting channels, only the registered channels can be received.

When each subscriber informs the center of the channel they wish to subscribe to, the contract channel data is stored in the memory 1o, read out and sent to the terminal by the data carrier along with address data for each subscriber, and the channel data is non-volatile. written to sexual memory. Therefore, when actually selecting a channel, it is only possible to receive that channel if the selected channel μ matches the channel registered in the non-volatile memory, and it is impossible to select other channels. .

Next, the scram ρ and disk clamp y methods of the 0ATV device shown in FIG. 1 will be explained with reference to FIGS. 3 to 6.

3 shows the overall configuration of the scrambler and descrambler parts, FIG. 4 shows a specific example of the structure of the scrambler 6, and FIG. 6 shows a specific example of the structure of the descrambler 23.

The scrambler 6 includes a sync separation circuit 41 that separates a sync signal from a video signal, and a reference sync signal generator 4 that generates a stable reference sync signal from the output of the sync separation circuit 41.
2. A vertical blanking pulse generator 43 that generates a vertical blanking pulse and a horizontal blanking pulse, respectively, based on the output of the generator 42. A horizontal blanking pulse generator 44, a synchronization signal level shift circuit 46 that uses the vertical blanking pulse and the horizontal plunging pass to shift the level to the video signal side for a certain period including each synchronization signal, and a vertical blanking pulse. A random pattern generator 46 generates a random pattern based on a scramble code sent from the microcomputer 9 as a timing signal. a video signal inverter 47 that inverts the polarity;
A first timing signal generator 48 inserts timing information for decoding a random pattern in the vertical retrace period at the timing of the vertical blanking pulse, and a first timing signal generator 48 is arranged before and after the timing information for decoding the random pattern in the vertical retrace period. and a second timing signal generator 49 for placing timing information indicative of the start position of the level shift of the synchronization signal.

On the other hand, as shown in FIG. 6, the descrambler 23 determines whether the RF television signal is a normal (unscrambled) television signal based on the presence or absence of timing information obtained by demodulating the RF television signal. A normal/scrump y discrimination circuit 61 determines whether the signal is a processed television digital signal, and based on this discrimination signal, if it is a normal television signal, the output terminal 52 is connected to the /-mar terminal N, and the output terminal 52 is connected to the /-mar terminal N, fi
If the signal has been processed, the microcomputer 2 (7) in the addressable controller/L/l unit 28 is connected to the output terminal 62 to the scramble terminal S.
Non-volatile memo based on the switch 63 controlled by 8 & and timing information to decipher the random pattern! Random pattern generator 54, which reads the scramble code written in J28b, decodes it by microcomputer 28.1L, and generates an output random pattern. - a video signal inverter 66 for converting the scrambled video signal into a normal video signal based on the random pattern signal; and a video signal inverter 66 for converting the scrambled video signal into a normal video signal, and synchronization in the video signal based on timing information indicating the start position of the synchronization signal level shift. It consists of a synchronization signal level shift circuit 66 for returning the signal level to its original correct state. The output end of this synchronizing signal level shift circuit 66 is connected to a scramble terminal S.

Next, its operation will be explained. The center line controller 8 determines a scramble mode and supplies the scramble code to the scrambler 6 and modem 13, respectively. The scramble code input to the modem 13 undergoes FSK modulation at a frequency of 73Mtlz and is sent to the terminal side through the mixer 3. On the other hand, in the scrambler 6, the synchronization signal is separated from the baseband video signal to create vertical blanking pulses and horizontal blanking pulses, and the synchronization signal level shift circuit 46
During the period of both blanking pulses (in the horizontal period, period & in the waveform of the video signal in FIG. 6), the level of the synchronizing signal is shifted to the video signal side. FIG. 7 shows the waveform of the video signal in which the synchronization signal is level-shifted as described above. The random pattern generator 46 uses the vertical blanking pulse as a timing signal! ,! : Then, a random pattern is generated according to the scramble code sent from the line controller 8. Using this random pattern signal, the video signal inverter 47 inverts the polarity of the video signal in which the level of the synchronizing signal has been shifted in units of one vertical period. Figures 7A and 7B show an example of the negative state. If M is an even field, B is an odd field, and the polarity of the video signal is inverted with respect to the even field.

The inverted state of this video signal can be set randomly and can be determined using a scrambling code. The first timing signal generator 48 uses the falling edge of the vertical blanking pulse as a timing to generate a timing signal (information) S+ of, for example, the 2-bit configuration shown in FIG. 1, for decoding a random pattern within the vertical blanking period. insert.

The second timing signal generator 49 adds a timing signal S2 indicating the start position of the level shift of the synchronization signal to the timing information for decoding the random pattern.

This timing signal is shown in FIG.

In this way, the level of the synchronization signal is shifted, and the video signal is synchronized with the scrambled baseband video signal whose polarity is randomly inverted in units of one vertical period based on the scramble code, and the timing information for random pattern decoding. Timing information indicating the starting position of the signal level shift is sent to the next modulator 7 along with the audio signal. In the modulator 7, the scrambled video signal and the audio signal are subjected to amplitude modulation 9 frequency modulation processing similar to that of a normal television signal, and timing information is amplitude-modulated on the audio carrier wave and sent out on the audio carrier wave. I have to. In this way, the video signal, audio signal and timing information are output from the modulator 7 as an RF television signal, and sent through the mixer 3 to the terminal.

In the modem 13, the scramble code is output to the terminal by the data carrier along with address data for each subscriber and subscribed channel data.

The scramble code and the channel data are demodulated via the modem 49 and written to the non-volatile memory IJ28b in the addressable control unit 48.

On the other hand, the RIF television signal is in the state before it is selected to any one channel by the channel selection device 26 and inputted to the modulator 7 by the demodulator 22, that is, a scrambled video signal and an audio signal.

It is demodulated into timing information, separated, and output.

The normal scramble determination circuit 61 determines that the scramble processing has been completed based on the presence of timing information, and sends the determination output to the microcomputer 28&. The microcomputer 28& connects the switch 63 to the scramble terminal S based on the above-mentioned discrimination output. On the other hand, the microcomputer 28& reads out and decodes the scramble code stored in the non-volatile memory 28b according to the timing information S1 for decoding the random pattern, and accordingly the random pattern generator 6
Control 4. The output signal of the random pattern generator 64 causes the video signal inverter 66 to restore the randomly inverted state of the scrambled video signal to a correct waveform. Then, in the next synchronization signal level shift circuit 66, the level of the synchronization signal is shifted to the original correct level based on the timing of the timing information S2, and the descrambled video signal is sent to the output terminal 62 via the souffle terminal S1 switch 63. Output. This normal video signal is input to the modulator 24 together with the audio signal at the terminal 67, modulated into an RF television signal of a specific channel, and supplied to the television receiver 2o. Therefore, an image is correctly displayed on the television screen of the television receiver 20.

Note that when scrambling processing is not performed, the switch 63 is connected to the normal terminal N, and the input video signal is outputted from the output terminal 62 as it is. According to this configuration, the polarity of the video signal is randomly inverted in units of one vertical period and the level of the synchronization signal is shifted to perform scrambling processing on the video signal. In order to restore the signal level shift, timing information indicating the level shift start position is sent to the terminal along with the video signal using an audio carrier wave, and a scramble code for determining the random pattern is sent to the terminal along with address data, etc. Notes on the terminal side! J 28b, decodes the scramble code in the memory 28b based on the timing information, generates a random pattern based on it, and restores the inverted state of the video signal to a normal state.
By descrambling the synchronization signal by level-shifting it to the original correct waveform based on the timing information, it is possible to increase the security of scrambling, which is more advantageous in practice.
The scramble mode can also be changed arbitrarily at the center.

In such a 0ATV device, in the present invention, the GMUTV
In order to prevent eavesdropping, a channel number code is attached to the
This channel number code is made into a code signal according to each channel to be transmitted, and is sent to the terminal as a high frequency television signal close to the horizontal synchronization immediately after the vertical retrace period of the video signal of the program, and at the terminal, the subscriber When a user selects a desired channel, a microcomputer reads whether or not the channel number code sent in the program matches the channel selection control in the converter, and they must match. In other words, the channel selection operation is disabled.

A detailed explanation will be given below using FIGS. 2, 4, and 6. In FIG. 4, a channel (OH) pulse generator 68 generates a code signal for distinguishing transmission channel numbers to prevent unauthorized viewing, and supplies it to the timing signal generator 48. This code signal can consist of 8 bits. This channel number code S4
is inserted in the first timing signal generator 48 adjacent to the horizontal synchronizing signal immediately after the vertical retrace period of the video signal. Of course, any one channel number is selected as this channel number code depending on the transmission channel. This channel number code signal is sent to the modulator 7 along with the other timing information mentioned above, and the modulator 7 amplitude-modulates the audio carrier wave and outputs it to the mixer 3.

On the other hand, in the terminal, the non-volatile memory 2 in the converter 19
8b, the center fin controller 8 is installed in advance.
The reception contract channel sent by the receiver is stored. When receiving a television signal to which a specific channel number code signal has been added, the subscriber inputs the desired channel selection into the keyboard 26 or the remote control transmitter 3 or the remote control unit 28. If this desired channel selection channel and the reception contract memory channel match, the channel selection operation is performed, but after that, the channel number code signal S4 in the received television signal matches the desired channel selection channel or the reception contract memory channel. The microcomputer 28& determines whether or not they match. If it is determined that it is, you can continue receiving television signals. If they do not match, the operation of the channel selection device 26 is stopped or a specific channel μ is selected. As a result, even if an attempt is made to eavesdrop by attaching a frequency converting device to the input of the converter 19, the channel number code signal S4 sent to the television broadcast signal and the selected channel will be changed.
Alternatively, since the reception contract storage channels are different, it is possible to stop the reception operation and prevent unauthorized viewing. In addition, the first
Although the channel number code signal S4 in the figure is 8 bits and has been described based on the presence or absence of bits, it goes without saying that the same effect can be obtained even if the bit width is varied (pulse width modulation). 1
The present invention can be applied to bidirectional C5τV or unidirectional C! Broadcasting via ATV or radio waves can also be widely implemented.

As described in detail, according to the present invention, the transmission channel number is determined in the vicinity of the horizontal synchronization signal immediately after the vertical retrace period of the video signal of the television signal flowing through the transmission line between the center and terminal converters. A Nodame code signal is inserted and sent to the terminal, and the channel number code indicating which channel is being received at the terminal and the desired channel selection or contract channel storage code signal sent in advance from the center are By determining whether or not they match, if they match, the program on that channel is received, and if they do not match, the channel cannot be received. Even if you install a device that converts channels and try to receive a channel to which you are not subscribed, by making it invisible, you can prevent unauthorized viewing and improve management security.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an ATV device to which a television device is applied according to an embodiment of the present invention. FIG. 2 is a timing diagram showing a method of transmitting timing information and channel number code signals in an embodiment of the present invention. Figure 3 is a block diagram showing the configuration of the scrambler descrambler part, Figure 4 is a block diagram showing the specific configuration of the scrambler which is the main part, and Figure 6 is a block diagram showing the specific configuration of the scrambler. , FIG. 6 is a waveform diagram of a normal video signal, and FIG. 7B is a waveform diagram of a scrambled video signal. 1...Antenna, 2...Retransmission device,
3...Mixer, 4...Other signal source, 6
．． 22...Demodulator, 6...Scrambler 17, 24...Modulator, 8...Line controller, 9,281L...・Microcomputer, 10...Memory, 17...
...Main amplifier, 18...Transmission line, 19...
Converter, 2o Television receiver, 21 Tuner, 23 Descrambler 126 Tuning device, 26
... Keyboard, 28 ... Addressable control unit, 13.29 ... Modem, 30 ... Remote control transmitter, 31 ...
...Remote control receiver, 60...PG pulse generator, 68...OH pulse generator, 59...
...Video signal, 60...timing information, PG code, and channel number code. Name of agent: Patent attorney Toshio Nakao and one other person
Dimension 3tl

Claims (2)

[Claims] (1) A television signal is transmitted through a transmission line connecting a center and a terminal, and a channel number is supplied from the center for each channel in the signal, and the center transmits a vertical line of the video signal in the television signal. Immediately after the retrace period, a code signal for TV channel identification is inserted in the vicinity of the horizontal synchronization signal, and when the terminal selects a channel, the desired channel selection or reception contract channel storage code signal sent in advance from the center is inserted. A means is provided to determine whether the channel number code signal sent from the center and the channel number code signal match or do not match, and if the two signals match, the channel selection operation is performed, and if they do not match, the channel selection operation is performed. A television device characterized in that it is configured so that no stations are broadcast. (2) If the desired channel selection or reception contract channel storage code does not match the channel number code signal sent from the center, the channel selection device is controlled to forcefully select a specific channel. A television device according to claim 1.