JPH02128587A - Catv terminal equipment - Google Patents

Abstract

PURPOSE:To easily switch the audio signal processing function of CATV terminal equipment in accordance with the desire of a subscriber by selectively setting the audio signal processing of the equipment to enable/disable based on contents of commands indicating permit/inhibit of the audio signal processing transmitted through a transmission line together with RF signals. CONSTITUTION:An electronic attenuator (ATT) 14 and mute switch 15 are provided on the audio signal path of the output of a demodulator 13 and an electric signal is impressed upon the control input of the demodulator 13 so that audio signals can be processed. In addition, a storing means 22a which stores contents of commands indicating the permit/inhibit of audio signal processing transmitted together with RF signals through a transmission line is provided. Then processes of the ATT 14 and mute switch 15 are selectively set to enable/disable states based on the storing content of the means 22a. Therefore, the CATV terminal equipment of a subscriber can be operated as equipment with or without an audio signal processing function in accordance with the desire of the subscriber.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a CATV terminal device.

[Conventional technology]

In a CATV system, a signal separated from a transmission cable is supplied to a TV receiver via a CATV terminal device. 2. Description of the Related Art Conventionally, some CATV terminal devices are capable of performing operations such as turning on/off the power, channel selection, and volume adjustment using a remote control device.

The volume adjustment function of CATV terminal equipment is generally
The receiver also has a volume adjustment function, which can be used to adjust the volume, so this function is not necessarily required for the terminal device. However, the volume adjustment using the remote control device in the CATV terminal equipment is
This eliminates the inconvenience of having to use a dedicated remote control device for the receiver, and is extremely convenient and effective for CATV subscribers. On the other hand, even if terminal devices with such functions are lent to subscribers unconditionally,
There is not much benefit to operating companies that provide CATV services, and their profits will not increase.

[Problem to be solved by the invention]

Therefore, the contract fee for subscribers who are lent a terminal device with a volume adjustment function is higher than the fee for a subscriber who is lent a terminal device that does not have this function. There is a desire to increase the company's profits.

In order to satisfy such requests, it is possible to prepare in advance terminal devices that have a volume adjustment function and devices that do not, and to install terminal devices that are lent to subscribers according to their wishes. In this case, two types of terminal equipment will be required, and in addition to making it impossible to reduce costs through the mass production effect of terminal equipment, it will also be necessary to change the contract after installing the terminal equipment and remove the volume adjustment function from the contract, or to add volume adjustment function to the contract. There are many problems, such as the need to replace the terminal device each time an adjustment function is added.

Therefore, the present invention solves the above-mentioned problems, and provides a CATV terminal device that can easily provide services with a volume adjustment function and a volume adjustment function heat service according to the wishes of subscribers without having to prepare two types of devices. The challenge is to provide the following.

[Means to solve the problem]

CATV made by the present invention to solve the above problems
The terminal device includes a converter that converts the frequency of the RF multiplied signal transmitted through the transmission path into an intermediate frequency signal, and a demodulator that demodulates the intermediate frequency signal obtained from the output of the converter and separates it into a video signal and an audio signal. , a modulator that modulates the audio signal and video signal obtained at the output of the demodulator and converts it into a specific channel signal, and a modulator that is provided in the audio signal path between the demodulator and the modulator, and a control input Audio signal processing means for processing audio signals using applied electric signals, and contents of commands for instructing permission/prohibition of audio signal processing transmitted together with the RF multiplied signal from the CATV operation center through the transmission path are stored. The apparatus is characterized in that the audio signal processing means selectively enables/disables audio signal processing by the audio signal processing means based on the storage contents of the storage means.

[For production]

In the above configuration, an audio signal processing means is provided in the audio signal path of the output of the demodulator, and an electrical signal is applied to the control input of the audio signal processing means to process the audio signal, and furthermore, the audio signal is processed through the transmission path. RF
Permission to process audio signals transmitted together with doubled signals/
A storage means is provided for storing contents of a command instructing prohibition, and audio signal processing by the audio signal processing means is selectively enabled based on the storage contents of the storage means.
Therefore, even if the terminal device is the same, the subscriber can easily change the audio signal by simply changing the command transmitted from the center and changing the contents of the command stored in the storage means according to the subscriber's wishes. It can work as a device with processing function and without audio signal processing function.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing an embodiment of the CATV terminal device according to the present invention. In the same figure, 11 is an input terminal of the CATV terminal device, and the input terminal is connected via a transmission path such as a coaxial cable (not shown). connected to the center as a headend.

12 is a converter, and the converter 12 is 50MH
A desired channel is selected from among the multi-channel video signals that are FM multiplexed and transmitted using the frequency band of 550MHz to 550MHz, and the video signal of the selected channel is frequency converted and Obtain a frequency signal (IF signal). A demodulator 13 demodulates the IF multiplied signal from the converter 12, and the demodulator 13 separates the IF multiplied signal into a video signal and an audio signal.

14 is an electronic attenuator (ATT);
14 attenuates the audio signal separated by the demodulator 13 in the relationship shown in FIG. 2 by a voltage corresponding to the volume adjustment level applied to its control input. 15 is a mute switch (SW), and the mute 5W15
is opened by the mute signal applied to its control input when muting the output signal of the electronic ATT 14,
Prevents audio signals from being supplied to subsequent stages.

Amplifiers 16a and 16b amplify the video signal from the demodulator 13 and the audio signal that has passed through the SW 15, respectively.

17 is a modulator, and the modulator 17 is connected to amplifiers 16a, 1
6b modulates the amplified video signal and audio signal to a frequency corresponding to the second or third empty channel of the TV receiver. 18 is a modulator 17
This is an output terminal for outputting a 2 or 3 channel RF multiplied signal modulated by a TV receiver (not shown). 19 is A
C is a relay contact connected between the power input terminal 20 and the AC outlet 21, and when the relay contact 19 is closed, it supplies AC power to a device connected to the AC outlet 21, such as a TV receiver. .

22 is a controller configured by a microcomputer (μ-COM) that operates according to a predetermined program. The controller 22 is the electronic type A
Generates control signals to control the TT 14, mute 5W 15, modulator 17 and relay contact 19. controller 2
2 has a storage section 22a made of RAM;
Necessary data among command signals from the above-mentioned center or a remote control device to be described later is selectively stored in a, and is used for various controls by the controller 22.

Note that the controller 22 has, for example, a backup power source so that the contents stored in the RAM constituting the storage section 22a are reliably retained even in the event of a power outage or the like.

23 is a band pass filter (BPF) connected to the input terminal 11, and the BPF 23 is connected to the FSK (frequency 5 shift) through a transmission cable.
(keying) selectively passes an external command modulated signal transmitted using a modulation method. 24 demodulates the external command modulation signal that has passed through the BPF 23 and outputs the BPS (by
The demodulator 24 converts the command demodulated signal into a command demodulated signal using the phase 5 shift method, and the command demodulated signal obtained by demodulation by the demodulator 24 is applied to the controller 22. The external command modulation signal is transmitted in a format as shown in FIG. 3, and a volume adjustment function permission/inhibition command, etc. is carried as command data and is transmitted from the center together with the RF multiplied signal. When the volume adjustment function permission/prohibition command is input to the controller 22, it is stored in the storage section 22a.

Reference numeral 25 denotes a remote control light receiving section, and the remote control light receiving section 25 receives a remote control optical signal from the remote control unit w26, converts it into an electrical signal, and applies the converted remote control signal to the controller 22. In response, the controller 22
generates the above control signal based on the above remote control signal,
This is applied to a predetermined controlled object.

For example, when a volume adjustment operation is performed using the remote control device 26, the controller 22 refers to the permission/prohibition command for the volume adjustment function stored in its internal storage section 22a, and if the permission command is stored, the controller 22 performs the adjustment. A voltage corresponding to the volume level is applied to the electronic ATT 14 as a control signal. When the permission command (prohibition command) is stored in the storage unit 22a, a fixed voltage unrelated to the adjusted volume level is applied to the electronic ATT 14 as a control signal.In other words, the electronic ATT 14 receives the command from the center. This allows the management company to easily make this volume adjustment function a billable object.

Further, when the power is turned off in the remote control device 26, the controller 22 generates a control signal to open the relay contact 19, and also generates a mute signal to open the mute 5W15 and turn off the audio signal output.

Note that 27 is a channel selection switch connected to the controller 22, and the switch 27 selects the carrier frequency used in the modulator 17 by changing the channel selection switch 27.
Channel or one of three channels.

In the above configuration, C
The operation of the ATV terminal device will be explained below.

The controller 22 performs 1. in the flowchart of FIG. In the first step S1, it is determined whether or not a command demodulation signal for controlling the operation of the terminal device shown in FIG. 3 has been input from the demodulator 24. When is YES, the process advances to step S2, and the determination is N because no command demodulated signal is input.
When the result is O, the process proceeds to another step (not shown) for performing another task.

In step S2, it is determined whether the command demodulated signal input from the demodulator 24 represents a volume adjustment function permission/prohibition command, and if the determination in step S2 is YES, that is, the volume adjustment function is permitted/prohibited. If it is a command, the process advances to step S3 and the determination is N.
If the command is other than O, the process proceeds to another step (not shown) for executing the work corresponding to the command. In step S3, data indicating the content of the command is stored as a flag in a predetermined location of the storage section 22a in the controller 22. For example, this flag is "rl" for a permitted command, and "0" for a prohibited command.
”. After that, return to your original job.

As a result of the above operations, the storage unit 22a of the controller 22 stores a flag indicating the contents of the volume adjustment permission/prohibition command transmitted together with the RF multiplied signal from the center via the transmission path.

Controller 22 also performs the tasks shown in the flowchart diagram of FIG. In the flowchart of FIG. 5, in the first step Sll, the remote control device 2
It is determined whether the remote control signal from 6 has been input via the remote control light receiving section 25 or not. When the determination in step Sll is YES, that is, when a remote control signal is input,
Proceeding to step S12, if the determination is NO, that is, no remote control signal is input, the process proceeds to another step (not shown) for performing another task.

In step 312, it is determined whether the remote control signal is generated by operating the volume adjustment key on the remote control device 26. The determination in step S12 is Y.
If ES, that is, the remote control signal is due to the operation of the volume adjustment key, the process advances to step S13, and the determination is No.
That is, when the remote control signal is not caused by the operation of the volume adjustment key, the process proceeds to a step (not shown) for performing the task corresponding to the key.

In step S13, the flag stored in the storage unit 22a in step S3 in the flowchart described above with reference to FIG.
Proceeding to step 1-4, it is determined whether the read flag allows or prohibits volume adjustment. Step S1
As a result of the determination in step 4, if the flag indicates permission, the process proceeds to step 315, and if the flag indicates prohibition, the process proceeds to step 316.

In step S15, a voltage control signal corresponding to the volume adjustment level input from the remote control device 26 is output,
In step S16, a fixed voltage control signal that is unrelated to the volume adjustment level input from the remote control device 26 is output. The control signal output from the controller 22 is applied to the electronic ATT 14, and the electronic AT
T14 is controlled to have an attenuation value according to the voltage value of the control signal, and the level of the audio signal passing through the electronic ATT14 is adjusted. And the above step S
After performing S15 and S16, the process returns to the original step (not shown).

In the above-mentioned embodiment, volume adjustment was explained as an example of audio signal processing, but the present invention is not limited to this, but also allows/prohibits audio multiplexing such as stereo, monaural, bilingual, etc., or specifies the contents of permission. It can be widely applied to differentiate terminal devices.

〔effect〕

As explained above, according to the present invention, in the above configuration, the content of a command instructing permission/inhibition of audio signal processing transmitted together with the RF signal through the transmission path is stored, and based on the stored content, Since the system enables or disables audio signal processing by the audio signal processing means selectively, the same device can easily process audio signals by simply changing the contents of the stored commands according to the subscriber's wishes. It can work as a device with and without audio signal processing capabilities.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the CATV terminal device according to the present invention, FIG. 2 is a characteristic diagram showing the control characteristics of the electronic ATT in FIG. 1, and FIG. 3 is a CATV terminal device from the center. FIGS. 4 and 5 are flowcharts showing the work performed by μmC0M, which constitutes the controller in FIG. 1. 12...Converter, 13...Demodulator, 14...
Electronic attenuator (volume adjustment means), 17...Modulator, 22...Controller, 22a...Storage unit (storage means) Patent applicant Pioneer Corporation

Claims (1)

[Claims] A converter that converts the frequency of an RF signal transmitted through a transmission line into an intermediate frequency signal, and a demodulator that demodulates the intermediate frequency signal obtained as the output of the converter and separates it into a video signal and an audio signal. an audio signal processing means that is provided on the audio signal path of the output of the demodulator and processes the audio signal using an electric signal applied to the control input; and an audio signal that is transmitted together with the RF signal through the transmission path. and storage means for storing contents of commands instructing permission/prohibition of processing, and selectively enabling/disabling audio signal processing by the audio signal processing means based on the stored contents of the storage means. A CATV terminal device characterized by the following.