JPS59219085A - Charged television system - Google Patents

Abstract

PURPOSE:To simplify the titled system by modulating a scramble signal at the transmission side by a control signal to the reception side and superimposing the resulted signal on a TV signal. CONSTITUTION:A modulating circuit 20 modulates a scramble signal from a scramble signal generating circuit 18 by a control signal from a control signal generating circuit 19. This modulated control signal is outputted to a coupling circuit 4 via a BPF11 and a level adjusting circuit 12. After the TV signal is superimposed by the coupling circuit 4, the signal is applied to a descrambler 7 at the reception side via a cable 5. The control signal is detected by a control signal detecting circuit 24 and contacts RY1, RY2 are controlled based on this detection signal. A notch filter 13 is connected between the cable 5 and a subscriber TV receiver 6. The system is simplified in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a 1% scrambler improvement for pay television systems in which enable/disable of the descrambler is controlled from the transmitter side to the subscriber side.

In a pay television system, the transmitting side (center) simultaneously transmits a television signal and a null signal consisting of frequencies within the same band, and the receiving side is equipped with a descrambler plan to remove the signal from the scrambler described above. The system is configured so that only subscribers can reproduce and view the television signals.

Figure 1 shows a line-up of a conventional pay television system, where numeral 1 is a signal section for generating the original television signal, and numeral 2 is a scrambler, which consists of a frequency signal within the same band as the television signal. It is comprised of a scramble signal generating circuit 3 for generating a null signal having a predetermined intensity that causes the television signal to deteriorate (attenuate) when received, and a coupling circuit 4 for combining the television signal and the scramble signal. , 5 is a cable, 6 is a television set on the subscriber side, which is connected to the cable 5 via a descrambler 7, and 8 is a television set on the non-subscriber side, which is directly connected to the cable 5.

In the above configuration, on the receiving side, the television set 6 on the subscriber side can receive a normal television signal as the null signal is removed by the descrambler 7, but on the television set 8 on the non-subscriber side, Since the television signal is attenuated by the hs scrambled signal, the television signal cannot be reproduced, and depending on the selection of overpassing one frequency, the sound is also attenuated.

8+! Figure 2 shows another conventional example, especially the scramble signal generation side w! 13, 9 is a first scramble signal 1g excavation circuit for generating a first scramble signal consisting of a frequency signal in the same band as the television signal, and 10 is a circuit connected to the first scramble signal. This signal processing sequence is used to generate a second scramble signal consisting of a low frequency signal to attenuate the television signal by AM modulation. 1 is a bandpass filter, and 12 is a level adjustment circuit.

In this case, the television set 8 on the non-subscriber side, which is not equipped with the tenu scrambler 7, will have its television signal attenuated by disturbances such as disturbances in the GC operation, which will prevent normal internal transmission.

Only the subscriber's Television Centro performs normal playback.

In the conventional column shown in FIG. 2, the descrambler 7 is composed only of a notch filter 13 as shown in FIG. 3, and operates to remove only the first scramble signal from the television signal and the first scramble signal. Let's do it.

Further, FIG. 4 shows another conventional column, and particularly shows the structure of the descrambler 7, in which 14 is a first filter, 15
is a second filter, 16 is a relay, and 17 is a coin box. By turning the relay 16 on and off by the coin box 17 and switching the filter, the signal from the cable 5 is passed through one of the filters to the television set 6. It was designed to be supplied to For example, when a coin is inserted into the coin box 17, the relay 16i
By switching to the first filter 14fM, the scramble signal is removed by the filter 14. In the opposite case, the second filter 15
The television signal or audio signal is degraded by
Become so.

By the way, in the conventional system as mentioned above.

Subscribers not only have to have a desk blanking plan but also have to pay a special fee in some cases to be able to watch television programs, which places an excessive burden on them, making system use complicated and expensive. was inevitable.

The present invention has been made to roughly address the above problems.

It is an object of the present invention to provide a pay television system which eliminates the drawbacks of the conventional system by being constructed such that a control signal on the transmitting side is modulated with a control signal for the receiving side and superimposed on the television signal. It is.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 5 shows a schematic diagram of a scramble signal generation circuit for constructing a pay television system according to an embodiment of the present invention.
The same parts as before are designated by the same numbers, and 18 is a scramble signal generation circuit which works to generate a scramble signal consisting of a frequency signal within the same band as the television signal.
19 is a control signal generation circuit which works to generate a control signal containing information for controlling the descrambler on the receiving side, and 19 is a modulation circuit which controls the scramble signal outputted from the scramble signal generation circuit 18. The control signal outputted from the signal circuit 19 is used to modulate (superimpose) the control signal.
is output to the coupling circuit 4.

The above control signals include various digital signals, tone signals,
Although signals based on various other systems are conceivable, a specific example of a control signal generating circuit that includes information content using a binary 2-bit digital signal as a - column will be described with reference to FIG.

In Figure 6, ES 1. ES2 is a switch for setting control signals (information), and is set to 1 and 0, respectively. 2J is a shift register, and is constituted by a shift register K (also serving as a data format) capable of outputting, for example, a binary 4-bit parallel input (sv'). η is a timing signal generation circuit that can be configured by, for example, a block excavation circuit, and is used to control the timing of circuit operation. It is used to generate a signal, and is an OR gate circuit.

The set information ('II, JJ, $O'') is transferred to the shift register 21 [*-do-f] under the control of the timing signal generation circuit 4. At this time, the start bit "0" and stop bit are set as fixed information. 11 is set and loaded into the shift register 2j at the same time.Next, under the control of the timing signal generation circuit ρ, the contents of the shift register 2I are serially output to the OR gate circuit along with the timing signal.At this time, the timing signal The signal from the generation circuit η to the OR gate circuit is formatted to be less than the start pid lo" (start-stop synchronization code).
Stay ahead of the information.

It is used to output a control signal in a form that separates information and clarifies the start speed.Here, 2 bits of continuous 1 state are used.However,
'11' does not exist as information.

Figure 7(a) shows an example of a control signal, where the first 0 following two or more consecutive 1's is a start bit, the following 2 bits (here 't', (1'') are information, and the next 61'' is a stop bit, and the following x pattern has different contents depending on the information sending procedure.

If regular information is sent out continuously, it will be a repeat of the previous signal.

By converting the scramble signal YAM output from the scramble signal excavation circuit 18 using the control signal of FIG. 7(a) output from the OR gate circuit 18, a scramble signal waveform as shown in FIG. 7(b) is obtained. can get.

This scrambled signal is supplied to a descrambler 7 via a cable 5.

FIG. 8 shows a descrambler included in a pay television system according to an embodiment of the present invention, where 5 is a control signal detection circuit that works to detect a control signal superimposed on a scrambled signal, and 5 is a switch. The control circuit reads information from the control signal detected by the detection circuit array and outputs the information to the contacts Ryl+Ry provided at both ends of the notch filter 13.
A specific example of the descrambler 7 will be described below with reference to FIG.

In FIG. 9, the control signal detection circuit 24 is composed of a filter station, an amplification/detection circuit, and a waveform shaping circuit. Further, the switching control circuit section includes a timing signal generation circuit 29. Shift register addition and comparison circuit 31. Latch circuit 32. relay 16
．． switch DS] and DS2.

The television signal input to the descrambler 7 from the cable 5 and the scrambled signal shown in FIG. 1
o Z A signal as shown in (a) is output, and after passing through the amplification and detection circuit 27, it is converted to the signal shown in Figure 1O (b) by the waveform shaping circuit 27.
) are output as two digitized signals.

On the other hand, the switching control circuit 5 is constituted by a general digital logic circuit, and information such as i and o'' are set in advance by the subscriber using switches DS, DS2, and are applied to the comparison circuit 31. is composed of a binary 2-bit shift register capable of serial input and parallel output.
b) Reading the digitized control signal and information
1. O or Nutoa. At the same time, the comparison circuit 31
Information also read in 1. , , # are added, the comparison circuit 31 outputs a logic l signal indicating a match as shown in FIG. 1O(C). Stop bit timing is enabled by stopping the shift register blades from shifting.

Next, FIG. 10(d) from timing signal generation circuit 4
The launch circuit 12 receives the signal shown in FIG. 1O (
The output information e) from the comparison circuit 31 as shown in e) is stored, and at the same time the relay 16 comes to operate as shown in Figure (f) of NfJ10.

As a result, the contacts Ryl+ at both ends of the notch filter 13
Since both Ry2 are switched to the notch filter 13 side, the scrambled signal is removed (reduced) from the input signal from the cable 5 by the original operation of the notch filter 13. Therefore, since only the regular Pue Television signal is supplied to the subscriber television station 6, a descrambling operation is performed.

7. 'iHN applied to ratio I bit circuit 31 matches. For example, if the received information is 11 hours, 0'' (ゝ o , , I
', the output of the comparator circuit 31 remains at 10'' and the relay 16 does not operate, so no descrambling operation is performed.

As long as the information received after the relay 16 operates once remains regular information, such as '1,0'.

The relay 16 remains on without being turned off.

In reality, once the relay 16 is turned on, it is set to a certain level so that it does not turn off immediately even if it receives incorrect information several times, or it does not turn on immediately even when a genuine code is received. The relay 16 can be configured to have a time delay, thereby preventing frequent switching operations of the relay 16 and preventing malfunctions.

As is clear from the above description, the present invention is configured so that the control signal is superimposed on the null-clamp signal on the transmitting side, so that the descrambler on the subscriber side can be controlled from the transmitting side depending on the information content of this control signal. Since enabling/disabling can be controlled, a simple and inexpensive pay television system can be provided.

The present invention makes it easy to implement particularly addressable (individual identification control) type systems, so that it can be applied to a wide range of applications.

Also, the information code used becomes more complex due to F) CA
It can also be applied to applications such as premium service, tearing, paper and knee service on TV.

Furthermore, it is an OJ capability to easily and inexpensively upgrade the functions of the 1'V system to the existing C.

Furthermore, it can be similarly applied to MATV systems.

[Brief explanation of drawings]

FIGS. 1 to 4 are block diagrams showing conventional examples,
Fig. 5, Fig. 6 3d, Fig. 8, Fig. 9 are all block diagrams showing embodiments of the present invention; Fig. 7 ta)y tb)
and FIGS. 10(a) to 10(f) are all temporary figures for explaining the present invention. 2... Scrambler, 3.18... Scramble Ray No. 8 generation circuit, 5... Cable, 6... Subscriber television set, 7... Tescrambler, 13...
・Notch filter, 16...Relay, 19...Control signal generation circuit, Addition...Modulation circuit, 2], 30...Shift register, ρ, 29...Timing signal generation circuit, B...・OR gate circuit, 24... Control'@1 input power plate output circuit, 6... Switching 1jl) both circuits, 26... Filter, 31... Comparison circuit, 32... Launch circuit,
E.S.I. ES2. DS, , L) S2...Switch, Ry
l+ Ry2°゛° contact. 45 Fig. 9-460- Fig. 10 (f) - One use■

Claims (1)

[Claims] 1. In a television system in which the scrambled signal is stopped from the television signal on the transmitting side and the scrambled signal is removed by a filter on the receiving side and only the television signal is output, the scrambled signal is not received on the transmitting side. Open side J to side
A pay television system configured to modulate the signal and superimpose it on the television signal.