JPS6032494A - Pay television channel selecting device - Google Patents

Abstract

PURPOSE:To prevent illegal looking and listening by extinguishing code data of a contract device and contract channel necessary for looking and listening stored in an RAM by opening the back cover of a television set. CONSTITUTION:Contracted selected channel data are stored in an RAM11. Identification circuits 7, 8 detect RF input signal, and an identification signal of selected channel from a video signal. A comparating and discriminating circuit 10 compares and discriminates the identification signals of circuits 7, 8 and memory data of the RAM11. A restoring circuit 12 sends out video signals of selected channel basing on the signal of the circuit 10. When the housing case of the RAM11 is opened, a power source circuit 13 extinguishes data stored in the RAM11. Accordingly, looking and listening of special programs by uncontracted device and looking and listening of channels other than contracted channel can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pay television channel selection device, particularly to a channel selection device for receiving paid special programs on CATV and the like.

In CATV, in addition to regular TV programs, special programs such as foreign movie programs are broadcast on other channels, and viewers can select and view these special programs as needed. At this time, there is a need for a channel selection device that is not easily intercepted.

Conventionally, in CATV and the like, trap circuits have been provided in all viewing monitors and the trap circuits have been short-circuited in order to allow only subscribers to view special programs. This poses a problem in that the special program can be easily viewed by removing the back cover of the viewing monitor and shorting the trap circuit.

In addition, only special programs are sent out through the CATV system (ML) by adjusting the level of the synchronization signal, and the monitors of those who do not have a contract will be out of synchronization and will not be able to view the program.

On the other hand, the subscriber's monitor is equipped with a restoration circuit that restores the reduced synchronization signal level to its original state, so the special program can be viewed. Even with such a device, there is a problem in that by adjusting the synchronization circuit or the like, a program other than Ir¥ can be easily viewed.

In addition, the subscriber's channel selection device (memory device (R
A code corresponding to the subscriber and a code corresponding to the subscribed 'Phi separate program channel are stored in this ROM. In addition to regular TV programs, signals for special programs and selections are sent from the CATV center.
The selection signal is received from the composite signal superimposed on the cable for A 'II' V and the RO
There was a selection device that compared the contents of M and decided whether or not to view a special program.

Even with this device, there was a problem in that the content could easily be viewed if operations such as rewriting the contents of the ROM were performed.

The present invention aims to solve the above problem. Therefore, the pay TV channel selection device of the present invention stores at least contracted channel selection data in advance in a pay TV channel selection device that makes it possible to receive the video signal of a predetermined channel from the HF input signal. a RAM, an identification circuit for detecting at least an identification signal of a selected channel from the HF input signal or the video signal, an identification signal from the identification circuit and the RAM;
a comparison judgment circuit that compares and judges data stored in the comparison judgment circuit; a restoration circuit that sends out a video signal of the selected channel based on a signal from the comparison judgment circuit; and at least when the case storing the RAM is opened; It is characterized by having a power supply circuit that erases data stored in the RAM. The present invention will be described in detail below based on the drawings.

Reference numeral 1 in the figure shows a keyboard switch, which is used to manually select a channel to view.

Reference numeral 2 denotes a channel selection circuit, which sends out a signal for selecting a station corresponding to the channel input from the keyboard switch 1.

3 in the figure is a frequency conversion circuit, which is a circuit that sends out a video signal of a channel selected from the HF input signal based on the channel selection signal from the A circuit 2, and 4 is a local oscillator, which is a 9-channel selection circuit. 2 is a circuit that generates a local oscillation frequency for selecting a frequency corresponding to the selected channel from 2, and 5 is a mixer, which is a circuit that mixes the RF input input signal and the local oscillation frequency. , 6 is a restoration circuit.

If a special program or the like is sent out in a temporally scrambled manner, this circuit restores it to its original state. With the above-described configuration, a predetermined station is selected from the HF input signal, and in the case of simplification (b), a video signal restored to its original state is output. The dotted line following the mixer 5 is a filter.

This indicates that the second mixer etc. are omitted.

Diagram 7 Al at FM receiver. The F M v C /<7 tunes into a special frequency band 9 of the HF input signal, for example, a 106.5 MHz frequency to which no channel is assigned, and receives an address signal for identifying the subscriber.

This received signal (analog) is supplied to the data generation circuit 9 (=supplied).

8 is an AM receiver. The AM receiver 8 receives the selected video signal from the frequency conversion circuit 3, receives an identification signal corresponding to the selected channel, and supplies this received signal (analog) to the data generation circuit 9. . This received identification signal is superimposed on each channel, so that the channel identification signal can be directly received from the nine selected video signals.

The data generation circuit 9 is a circuit that converts the respective signals from the FM receiver 7 and AM receiver 8 into digital signals and supplies the digital signals to the control circuit 10.

10 in the figure is a control circuit. The control circuit 10 is a RAM
11 f = The data input from the data generation circuit 9, that is, the contract transmitted through a special channel, by reading out and referring to the stored code data corresponding to the subscriber and contracted channel data, etc. The appropriateness of the code data corresponding to the user or the reception channel data superimposed on the selected channel is determined. If the currently received channel is a contracted channel by a contracted device, the control circuit 10 controls the restoration drive circuit 12.
The restoration signal is then sent to 'f'. The restoration drive circuit 12 sends a predetermined restoration signal to the restoration Q circuit 6 to restore the scrambled video signal to the original video signal state.

In the RAM 1.1, code data to send to the contracted device, channel data corresponding to the contracted special channel, etc. are stored in a predetermined code. , the written contents are erased and stored in -C. In the conventional configuration, the contents were only written in R()M, so that experts could easily know the contents.9 However, in the present invention, the contents are written in RAM, and it is possible to detect when a predetermined operating state occurs. As a result, its contents disappear, so its contents cannot be known. In addition, since the code data of the contract device and the like are stored in the RAM 1, it is possible to easily change the contract channel. For example, it is also possible to change based on the signal from the FM receiver 7.

I3 in the figure is a power supply circuit, and when a third party opens the back cover of the television set to which the device of the present invention is attached without the installer's permission, the switch 14 becomes open, and the RAMI
The contents of I disappear. That is.

When the switch 14 is open and a predetermined voltage VCc is applied from the DC power supply 15 (DC power "E source" obtained by rectifying the commercial power supply).
is occurring, the H level signal of the non-grounded terminal (■) of the switch I4 is input to the control circuit 10, and the control circuit 10
erases the contents of RAM1l. In addition, when the switch [4] is in the open state and the predetermined voltage VCC is not generated from the DC power supply 15 (in a power outage state or when the power cord related to the device of the present invention is pulled out), the backup battery The voltage from 16 is applied to RAM 11
Since the data is not supplied to RAMII, the contents of RAMII are lost. 1. Power for each circuit shown in the figure is supplied from DC source 15 (cc). Note that even if the DC voltage Vcc disappears due to, for example, a power outage in the commercial power supply, while the switch 14 is normally closed.

Since power is supplied to RAM II from the battery 16, there is no problem. Further, the backup battery 16 is floatingly charged by a DC power source 15 or the like.

As explained above, according to the present invention, the code data of the contracted device necessary for viewing special programs, etc.

If you store the code data of the subscribed channel in a RAM with a backup battery, and open the back cover of the TV to which the device is attached, the contents of the RAM will be erased, so you will not be able to watch special programs or watch special programs on devices that are not subscribed. It is possible to almost completely prevent viewing of special programs on channels other than those on which you have subscribed.

[Brief explanation of the drawing]

The figure shows a block diagram of one embodiment of the invention. In the figure, 1 is a keyboard switch, and 2 is a tuning circuit. 3 is a frequency conversion circuit, 6 is a restoration circuit, 7 is an FM receiver, 8 is an AM receiver, and 9 is a data generation circuit. 10 is a control circuit, 11 is a RAM, 12 is a restoration drive circuit, 13 is a power supply circuit, and 14 is a switch. Reference numeral 5 represents a DC power supply, and reference numeral 16 represents a backup battery. Patent applicant Alps Electric Co., Ltd.

Claims (1)

[Claims] A pay TV channel selection device that enables selection of a video signal of a predetermined channel only to a contracted device from an RF input signal, comprising a RAM for storing at least contracted channel selection data in advance, and a RAM for storing at least contracted channel selection data from the RF input signal or the video signal. an identification circuit that detects an identification signal of at least the selected channel; a comparison judgment circuit that compares and judges the identification signal from the identification circuit and data stored in the RAM; and a signal C from the comparison judgment circuit. a restoration circuit that transmits a video signal of the selected channel;
A pay TV channel selection device comprising at least a power supply circuit that erases data stored in the RAM when a case storing the RAM is opened.