JPS63234684A - Terminal equipment for catv - Google Patents

Abstract

PURPOSE:To prevent furtive audience by providing a control section whose stationary member is released regardless of power on/off from a power receptacle, detecting the open state of a switch when the cover is removed there by giving the channel selection to a specific channel only. CONSTITUTION:With a power receptacle plugged into on AC socket, a switch 4 is opened by opening the cover, a voltage of a 5V line 7 is decreased, a control section 5 detects it to apply special processing selecting a channel from a specific channel among the receptible channels from the CATV. When the power receptacle is not plugged into AC plug or in case of power failure, when the switch 4 is opened, the voltage of 5V line 8 is dropped and the data of a RAM 6 is lost. In applying the power receptacle to the AC plug again, the control section 5 detects the loss of the preceding specific check data in the RAM 6 to apply the processing enabling to select only a specific channel. Thus, furtive audience is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a CATV terminal device27, and in particular to a CATV terminal device that can cope with internal tampering by a subscriber or a third party. It is.

2. Description of the Related Art In recent years, with the development of CATV, paid programs have become popular. Subscribers usually subscribe to the channels they want to watch for each blade. The video signals of pay programs undergo some kind of signal processing (this is called scrambling), so that a normal screen cannot be obtained if they are left unchanged. In addition, in order to prevent unauthorized viewing by opening the case of the terminal device and making changes to the circuit, special screws are used to close the lid, and special stickers are pasted on the screws. To prevent unauthorized viewing, the seal must be broken in order to open the screw.

Problems to be Solved by the Invention However, with such conventional methods, once the lid is opened in some way, unauthorized viewing is inevitable. Particularly in a one-way system, it is not possible to monitor the status of the terminal device at the center, so this eavesdropping poses a big problem for the operator.

The present invention has been made based on the above-mentioned circumstances, and it is an object of the present invention to provide a terminal device in which only a specific channel can be selected when the screws on the casing of the terminal device are released and the lid is removed.

Means for Solving the Problems In order to achieve the above object, the present invention has the following objectives: When the fixing member is released and the cover is removed, regardless of whether the power supply from the i-source outlet is on or off, the switch is removed. It is equipped with a control section that detects the open state and allows only specific channels to be selected.

According to the above-described structure, the switch is automatically opened when the lid is opened, and the control unit detects this and can select only a specific channel.
You can prevent eavesdropping.

EXAMPLE Hereinafter, an example of the present invention will be described from the beginning with reference to the drawings. FIG. 1 shows "0" in one embodiment of the present invention.
This is a block diagram of an ATV terminal device, and the television signal processing section and data signal processing section are omitted. In FIG. 1, 1 is the power supply 6V line, and 2 is the 6V line after the voltage of the power supply 6V line 1 has been dropped by a resistor and a diode. 3 is a backup battery that operates when the power outlet is unplugged or during a power outage.

4 is a switch composed of a housing and a printed circuit board. 6 is a control section of the terminal device. 6dR
In the AM, data necessary for controlling the terminal device is stored. 7 is a 6V line and is connected to the 6V detection terminal of the control unit 6. 8 is 5v
It is connected to the power supply terminal of RAM e by a line. 9 is a bus that controls RAM6, and 1o
is a data bus that sends data from the RAM 6 to the control section 6.

First, the power outlet is connected to the AC plug 2 and SA-.

We will explain the operation when In this state, the control unit 6 and RAM 6 are in an operating state. When the switch 4 is opened by opening the lid, the voltage of the 6V line 7 drops, and the control unit 6 detects this and selects only a specific channel from among the channels that can be received from the CATV. Perform specific processing that will no longer be possible.

Next, we will explain the operation when the AC plug is not connected to the power outlet or when there is a power outage. In this state, the control unit 5 and RAM e are in standby state and do not operate. Control parts 5 and R in advance.
When AMe is in operation, specific check data is stored in RAMe. Similarly to the above, when the switch 4 is opened, the voltage of the 6v line 8 drops and the RA
M6 data will be deleted. When the power outlet is connected to the AC plug again, the control unit 6
:) It is detected that the specific check data has disappeared, and only a specific channel can be selected in the same manner as above.68 FIG. 2 shows the switch 4 in FIG. 1.

In FIG. 2, the lid 11 is a 11# Si lid, and inside the lid 11 there is provided a metal plate 12 that constitutes a switch. 13 is a bridge pattern for configuring a switch provided on the printed circuit board. 14 is a casing for receiving a printed circuit board.

Numeral 15 is a screw for integrally fixing the lid 11, the bridge pattern 13, and the housing 14. When the screw 16 is closed, the switch constituted by the metal plate 12 and the bridge pattern 13 abuts each other and is in the closed state. When the screw 16 is released and the lid 11 is removed, the front The switch is in the open state. The control unit 6Fi detects the opening/closing state as described above and performs the above-mentioned specific processing to prevent unauthorized viewing by changing the internal circuit when the lid is opened illegally by a subscriber or the like.

Effects of the Invention As described above, the present invention provides benefits to subscribers or third parties7A-
7, and its practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a CATV terminal device according to an embodiment of the present invention, and FIG. 2 is a diagram showing the same switch. 1...Power supply 6v line, 2...5v line, 3...Backup battery, 4...
...Switch, 5...Control section, 6...
...RAM, 7.8...5V line, 9.
...Bus, 1o...Data bus, 11.
...Lid, 12...Metal plate, 13...
... Bridge pattern, 14 ... Housing, 15.
·····screw. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A casing that houses a CATV terminal circuit, a lid that closes the casing, a switch section that is composed of the lid and a printed circuit board and that is turned on and off depending on whether the lid is opened or closed, and the casing. A fixing member for fixing the printed circuit board and the lid together, and a power supply unit for operating the CATV terminal circuit even when the power outlet is unplugged, and turning on the power supply from the power outlet; The CATV is characterized by comprising a control unit that detects the open state of the switch and makes it possible to select only a specific channel when the fixing member is released and the lid is removed regardless of the off state. terminal device.