JPH05199525A - Satellite receiver - Google Patents

Abstract

(57) [Summary] [Purpose] To enable on-screen display of message information, etc. when receiving pay broadcasts sent on satellite independent data channels. [Structure] An error correction / deinterleave circuit output in the PCM demodulator 32 is used as an input, and an independent data extraction circuit 40 that extracts independent data sent together with a digital voice signal and an output of the independent data extraction circuit 40 are used as inputs. A character display circuit 41 for generating a video signal of a figure and a character from independent data, and a video mixing which mixes or switches the video signal and the character signal by the independent data with the output of the character display circuit 41 and the output of the video signal amplification circuit 23 as inputs. /
A switching circuit 24 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite broadcast receiver.

[0002]

2. Description of the Related Art In recent years, satellite broadcasting can be done by private satellite broadcasting stations, and PCM audio services are provided not only as video but also as independent audio, and the spread of receivers is remarkable.
Satellite receivers built into televisions are also increasing. FIG. 2 is a diagram showing a configuration of a conventional satellite broadcast receiver, in which reference numeral 10 is an input terminal for a first intermediate frequency signal.
This terminal 10 has 1 from the satellite received by the antenna.
A first intermediate frequency signal, which is converted into a frequency of 1 GHz by a down converter and guided indoors by a coaxial cable, is applied. 11 is a channel selection circuit, 12 is a channel filter, 13 is an FM demodulator, and 20 is 4.5 MH.
z low-pass filter, 21 is a de-emphasis circuit, 2
2 is an energy diffusion signal removal circuit, 23 is a video signal amplification circuit, 30 is a 5.73 MHz band pass filter, 31
Is a QPSK demodulator, 32 is a PCM demodulator, and 33 is a D / A
Converter, 34 low-pass filter, 50 video signal output terminal, 51 left audio output terminal, 52 right audio output terminal,
53 is an FM detection output terminal and 54 is a bit stream terminal.

The operation of the satellite broadcast receiver configured as described above will be described. The tuning circuit 11 selects a number of first intermediate frequency signals and converts one channel into a predetermined second intermediate frequency signal. For frequency conversion in the channel selection circuit 11, a highly accurate PLL synthesizer is generally used. The channel filter 12 is a bandpass filter that passes only one wave, and a SAW filter or the like is generally used. The FM demodulator 13 demodulates the selected FM signal to obtain a detection output signal. The FM detection output signal is separated into a video signal and an audio signal by the 4.5 MHz low pass filter 20 and the 5.73 MHz band pass filter 30.

The separated video signal is signal-amplified by the de-emphasis circuit 21, the energy diffusion signal removing circuit 22, and the video signal amplifying circuit 23, and 1 is applied to the video signal output terminal 50.
It outputs a Vp-p video signal. In the separated voice signal, 31 is a QPSK demodulator, which demodulates the voice signal QPSK-modulated into 5.7 MHz subcarriers and plays a role of extracting I and Q baseband signals orthogonal to each other.

The I and Q baseband signals are converted into PCM-coded digital signals (bit streams) by differential conversion. This PCM-encoded digital signal is deinterleaved, which is a PCM demodulation process in the PCM demodulator 32. And a circuit that restores it), range bits, and control signals are processed.

The output signal of the PCM demodulator 32 is converted into an analog signal by the D / A converter 33 and is output to the output terminals 51 and 52 as a voice baseband signal (L, R) via the low pass filter 34. .. When a pay broadcast is received, the output signals from the FM detection output terminal 53 and the bit stream output terminal 54 are connected to the pay descramble unit to scramble (disturb).
The video signal and the audio signal which are multiplied are restored.

By the way, as for the present satellite broadcasting, a private satellite broadcasting station has been established, and one channel is provided for each of television broadcasting and PCM audio broadcasting by a pay method, but with the development of satellite broadcasting in the future. It is expected that the number of private satellite broadcasts will increase and the number of pay-type broadcasts will increase.
In pay broadcasting, video signals and audio signals are scrambled, respectively, and the receiver unscrambles the data with a pay scramble decoder according to the contract with the broadcaster for viewing. As the number of pay-type broadcasts increases, various contract forms (for example, a form in which all programs can be viewed by paying a fixed fee within the contract period, a form in which the viewed program is charged, etc.) are present. Accordingly, the message information is transmitted by using the independent data channel which is transmitted together with the voice signal.

[0008]

However, the above-described conventional satellite broadcast receiver configuration has a problem in that these message information cannot be obtained, and such a new broadcast format cannot be supported. Therefore, an object of the present invention is to provide a satellite broadcast receiver capable of responding to new needs by enabling on-screen display of message information and the like transmitted on satellite independent data channels.

[0009]

The satellite broadcast receiver of the present invention is an independent data extraction for extracting the independent data sent together with the digital voice signal by using the error correction and deinterleave circuit output in the PCM demodulator as an input. Circuit,
A character display circuit that creates an image signal of figures and characters from the independent data by using the output of the independent data extraction circuit as an input, and a character signal by the image signal and the independent data that receives the output of the character display circuit and the output of the image signal amplification circuit An image mixing / switching circuit is provided for mixing or switching between.

[0010]

According to the structure of the present invention, the output signal of the error correction / deinterleave circuit in the PCM demodulator is input to the independent data extraction circuit, and the independent data sent together with the voice signal is extracted. This independent data is input to the character display circuit and is generated as a video signal of characters and figures. The character signal based on the independent data generated in this way is input to the video signal mixing / switching circuit that mixes or switches the video signal and the character signal together with the output of the video signal amplifier circuit, and the character information based on the independent data alone or on the TV screen is displayed. It is displayed superimposed on satellite broadcasting. In this way, it becomes possible to display the message information and the like transmitted on the independent data channel on the screen of the television.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a satellite broadcast receiver according to an embodiment of the present invention, which enables message information and the like transmitted on an independent data channel of satellite broadcast to be displayed on-screen on a screen of a television. Therefore, the PCM demodulator 32 is provided with the independent data extraction circuit 40 and the character display circuit 41, and the output signal of the character display circuit 41 is output from the video output terminal 50 either by the message information alone or by superimposing it on the satellite broadcast video. It differs from the conventional example in that a video signal mixing / switching circuit 24 is provided so as to output, and the other constituent elements are the same as the conventional example and perform the same operation.

With this configuration, supplementary items regarding contracts for each pay channel and diversification of contract modes accompanying an increase in pay satellite broadcasting channels are provided.
It becomes possible to deal with the possibility that the price per program in the case of a contract to pay the fee for each viewed program is transmitted as message information on the independent data channel.

That is, in order to display such message information on-screen on the television screen, the error correction in the PCM demodulator 32, the deinterleave circuit output signal, and the independent data extraction circuit 4 which is sent together with the audio signal.
By inputting 0, the message information at the time of receiving the pay broadcast is extracted and input to the character display circuit 41. Character display circuit 4
1 is a storage device for temporarily storing the extracted message information and the like, a character generator for demodulating the message information and generating a dot pattern of characters and symbols to be displayed on the screen,
It is composed of a display memory that stores the dot pattern and a central processing unit that controls each device, and generates a video signal of characters and symbols according to the message information. Character display circuit 4
The output signal No. 1 is input to the video mixing / switching circuit 24 and is output from the video signal output terminal 50 in response to the receiver's request, by superimposing the message information alone or on the satellite broadcast video.

In the case of pay broadcasting, "program information" including information about programs and keys necessary for descrambling,
"Control information" for instructing forced on / off of the function of the descramble unit, "individual information" including contract information for each subscriber, work information for decrypting program information and control information
Are encrypted and sent on an independent data channel. These pieces of information are reconstituted by the pay descramble unit, but the code signal indicating the individual contract status and the expiration date of the contract is extracted from the demodulated information from the pay descramble unit, and the information is input from the related information input terminal 60. By inputting to the display circuit 41, the contract status with the broadcaster can be displayed on-screen on the television screen.

[0015]

According to the satellite broadcast receiver of the present invention, it is possible to display on-screen the message information and the like of pay broadcasts transmitted on independent data channels of satellite broadcasts on the television screen.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a satellite broadcast receiver that is an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a satellite broadcast receiver in a conventional example.

[Explanation of symbols]

 10 1st intermediate frequency signal input terminal 11 Channel selection circuit 12 Channel filter 13 FM demodulator 20 4.5MHz low pass filter 21 De-emphasis circuit 22 Energy spread signal removal circuit 23 Video signal amplification circuit 24 Video signal mixing / switching circuit 30 5.73 MHz band pass filter 31 QPSK demodulator 32 PCM demodulator 33 D / A converter 34 Low pass filter 40 Independent data extraction circuit 41 Character display circuit 50 Video signal output circuit 51 Left audio signal output terminal 52 Right audio signal output terminal 53 FM detection signal output terminal 54 Bit stream output terminal 60 Related information input terminal

Claims (1)

[Claims] 1. A channel selection circuit which receives a radio wave from a satellite and frequency-converts a first intermediate frequency signal as an input signal, and a channel filter which receives an output of the channel selection circuit as an input and passes only a desired FM signal. , An FM demodulator which receives the output signal of the channel filter, a video signal processing circuit which inputs the detection output signal of the FM demodulator and outputs a video signal, and a detection output signal of the FM demodulator A QPSK demodulator for demodulating a voice subcarrier, and the QP
A PCM demodulator that inputs the output signal of the SK demodulator and performs PCM demodulation of the PCM-encoded digital voice signal, and a D / D converter that inputs the output signal of the PCM demodulator and converts the digital voice signal into an analog voice signal. A satellite broadcast receiver comprising an A converter and a low-pass filter for removing an out-of-voice band noise by using an output signal of the D / A converter as an input signal, wherein error correction and deinterleave in the PCM demodulator are performed. An independent data extraction circuit that extracts the independent data sent together with the digital audio signal by using the circuit output as an input, and a character display circuit that creates a video signal of a figure and a character from the independent data by using the output of the independent data extraction circuit as an input, The output of the character display circuit and the output of the video signal processing circuit are input, and the video signal and the character signal of independent data are mixed or switched. A satellite broadcast receiver characterized by having a video mixing / switching circuit for switching.