JPS631172A - Audio signal receiver - Google Patents

Abstract

PURPOSE:To attain the automatic channel selection even with diversified transmission modes by storing various kinds of format information into a memory in advance as to a transmitted audio signal. CONSTITUTION:The information such as the transmission mode and a frequency of a subcarrier signal are stored in a memory 9 in advance as to an audio signal of each channel. An audio signal processing section 5 separates an audio signal component from a base band signal BB and after a prescribed audio signal is detected, the result is fed to, e.g., a speaker equipment 7, from which sound is generated. A controller 3 supplies a frequency command signal AFRE to a programmable divider of a local oscillation circuit 13 so as to obtain just tuning based on a just tuning signal JTUN from an IF count circuit 23 discriminating whether or not the center frequency of an audio intermediate frequency signal AIF1 is a prescribed frequency based on the frequency signal FRQ used by an FM demodulation circuit 17 at the demodulation.

Description

[Detailed description of the invention] The present invention will be explained in the following order.

A. Industrial field of application B. Overview of the invention C. Conventional technology Problems to be solved by the invention E. Means for solving the problems (Fig. 1) F. Effects (Fig. 1)
Figure) G Embodiment (Figures 1 to 3) H Effects of the Invention A Field of Industrial Application The present invention relates to an audio signal receiver, and can be applied to, for example, a satellite broadcast receiver.

B. Summary of the Invention The present invention provides an audio signal receiver capable of receiving audio signals of multiple channels in multiple transmission modes, in which predetermined information regarding the audio signals of each channel is stored in a memory in advance, and an automatic channel selection mode is selected. Sometimes,
By reading the stored information from the memory for the designated transmission mode and performing the tuning operation, automatic tuning operation is made possible even when there are a wide variety of transmission modes.

C. Prior Art Satellite broadcasting using the 4 (GHz) band, so-called C-band, is widely used in the American continent. Satellite broadcasting using this C band is mainly CAT
Although it was developed and developed as a broadcast for key V (cable television) stations, reception on an individual basis is also permitted, and many such satellite broadcast receivers are now commercially available.

Currently, there are approximately 2 artificial satellites used for such satellite broadcasting.
There are 0 satellites, and each satellite broadcasts multiple channels. Moreover, in order to effectively use the band, each broadcast channel includes not only one television broadcast but also several (the most common is six) audio broadcasts (hereinafter referred to as audio channels).

D Problems to be Solved by the Invention Therefore, under the above-mentioned circumstances, there are a large number of audio channels that can be received by a satellite broadcasting receiver at a certain point in time, and the listener can select the desired audio channel from among them. It required many operations to select a station.

Therefore, it is conceivable to equip the receiver with an automatic channel selection function.

However, since this kind of satellite broadcasting is originally intended for broadcasting between stations, the services are diverse.
For example, in stereo broadcasting mode, two subcarrier signals are used, and each subcarrier signal is the left audio signal (hereinafter referred to as the L signal). Discrete mode transmits the right audio signal (hereinafter referred to as R signal) and the right audio signal (hereinafter referred to as R signal), or a discrete mode in which two subcarrier signals are used and each subcarrier signal transmits the sum signal L+R and difference signal of the L signal and R signal, respectively. Various methods are applied, such as a matrix mode in which L-R is transmitted, and a multiplex mode in which a sum signal L+R and a difference signal L-R are transmitted by one subcarrier signal using a pilot signal. ing.

Furthermore, monaural mode is also used.

Therefore, the satellite broadcasting receiver has a wide variety of modes, and the configuration for realizing the automatic tuning function used in conventional audio signal receivers for broadcasting other than satellite broadcasting cannot be used as is. I can't.

The present invention has been made in consideration of the above points, and is capable of automatically and quickly selecting an audio broadcast desired by a listener, and is also capable of supporting audio signals of many transmission modes. The present invention seeks to provide an audio signal receiver.

E Means for Solving Problems In order to solve these problems, the present invention provides a method for transmitting multiple channels of audio signals in multiple transmission modes, including a stereo audio signal in a transmission mode using two subcarrier signals. In the audio signal receiver 1 that can receive the audio signal, the transmission mode MODE and the frequency FR of the subcarrier signal are determined for the audio signal of each channel.
EQI.

The information of FREQ2 is stored in the memory 9 in advance, and when the automatic tuning mode is selected, the stored information is read out from the memory 9 regarding the transmission mode specified via the input device 8 and the tuning operation is performed. .

Some audio channels use one wave of the two-effect subcarrier signal, while other audio channels use two waves. Furthermore, there are various ways of transmitting the L signal and the R signal.

Therefore, simply capturing one subcarrier signal component does not result in tuning, and it is not possible to generate audio.

Therefore, information such as the transmission mode for each audio channel is stored in advance in the memory 9, and the stored contents are used to select the transmission mode specified during the automatic channel selection operation to generate audio output.

Embodiment G An embodiment in which the present invention is applied to a satellite broadcasting receiver will be described below with reference to the drawings.

In FIG. 1, l indicates a satellite broadcasting receiver as a whole, and broadcast radio waves (for example, 4 (GHz) band) received by a parabolic antenna (not shown) are transmitted to a converter (
(not shown), the signal is frequency-converted into a 1 (Gllz) band electrical signal RF, and then provided to the satellite broadcasting receiver l.

In the satellite broadcasting receiver 1, the incoming reception signal RF is received by the tuner section 2, and the tuner section 2 selects a predetermined broadcast channel based on the channel selection signal CH3E given from the controller 3 configured with a microcomputer, and performs FM detection. Then, a baseband signal BB including a video signal and an audio signal is provided to a video signal processing section 4 and an audio signal processing section 5.

The video signal processing section 4 separates a video signal from the baseband signal BB, converts it into a signal capable of driving a display device 6 having a CRT configuration, for example, and causes the display device 6 to display the received image. On the other hand, the audio signal processing unit 5 has a detailed configuration shown in FIG. It is designed to generate sound. Note that the video signal processing section 4 has a built-in character generator, and the controller 3
Messages are also displayed on the display device 6 based on command signals from the controller.

The audio signal processing section 5 will be described in detail below. In the audio signal processing unit 5, only the audio signal component AUD is separated from the baseband signal BB via a bandpass filter 10 that passes a band assigned to the audio signal component (for example, 5 to 8.5 (MHz)). and gives it to mix circuits 11 and 12.

As described above, in satellite broadcasting, there is a mode in which a stereo audio signal is transmitted using two subcarrier signals, so the receiver 1 has two systems as an audio signal reception/detection section.

The mix circuits 11 and 12 of each series have corresponding P
The local oscillation signal LO3 is generated from the local oscillation circuits 13 and 14 having the L L (phase 1 locked 1 loop) configuration.
1, LOS2 is given. Each mix circuit 11.12
is the audio signal component AUD and each local oscillation signal Los
t and LO32 to generate an audio intermediate frequency signal AI.
FI, AlF2 are obtained, and each bandpass filter 15
．． 16 to the FM demodulation circuits 17 and 18.

The FM demodulation circuit 17 demodulates the incoming audio intermediate frequency signal AIFI and provides the detected output signal DETI to the stereo decoder 19, and the other FM demodulation circuit 18 FM demodulates the incoming audio intermediate frequency signal ATF2. The detected output signal DET2 is given to the mode selection circuit 20.

The stereo decoder 19 determines whether a pilot signal representing stereo broadcasting is included in the detection output signal DET1, and if it is not included, the detection output signal DET1 is
I is applied to the mode selection circuit 20. On the other hand, if the detection output signal DETI includes a pilot signal, the stereo decoder 19 uses a logic "" which indicates that the audio signal transmission mode is the multiplex mode.
The multiplex signal MPX of "H" level is sent to the controller 3, and the detection output signal DETI is converted into an L signal and an R signal (No. 3), and is given to the mode selection circuit 20.

The mode selection circuit 20 performs signal conversion processing according to the transmission mode of the received audio signal based on the mode switching signal MOD arriving from the controller 3. In the monaural mode, the mode selection circuit 20 performs signal conversion processing according to the transmission mode of the received audio signal. The output signal DETI is sent to the volume adjustment circuit 21 from two output terminals, and when in the multiplex mode, the L signal and R signal given from the stereo decoder 19 are sent to the volume adjustment circuit 21, respectively, and when in the discrete mode, the L signal and R signal given from the stereo decoder 19 are sent to the volume adjustment circuit 21. The detection output signal DETI given from the FM demodulation circuit 19 is sent as an L signal, and the detection output signal DET2 given from the FM demodulation circuit 18 is sent as an R signal to the volume adjustment circuit 21. Furthermore, in the matrix mode, the re-detection output signals DETI and DET2 are sent to the volume adjustment circuit 21.
is subjected to matrix processing to form an L signal and an R signal, which are sent to the volume adjustment circuit 21.

The volume adjustment circuit 21 receives the L from the mode selection circuit 20 based on the volume control signal VOL given from the controller 3.
The muting circuit 2 adjusts the amplitude of the signal and the R signal.
2 to the speaker f7. In this way, stereo broadcasting or monaural broadcasting is performed. Note that, when the muting command signal MUTE is applied from the controller 3, the muting circuit 22 prevents the L signal and the R signal from being sent to the speaker device 7, and mutes the speaker device 7.

In addition to the above configuration, the satellite broadcast receiver 1 has an audio signal tuning configuration. In this embodiment, when the audio mode key of the key-powered device 8 is turned on, the audio map MAP stored in the memory 9 is
(Fig. 3) to execute automatic channel selection operation.

Here, the local oscillation circuits 13 and 14 having the PLL circuit configuration described above are configured to include a programmable divider, and the controller 3 generates the audio intermediate frequency signal AIFI based on the frequency signal FRQ used by the FM demodulation circuit 17 during demodulation. If the center frequency is a predetermined frequency (for example, 10.
7 (MHz)) from the IF count circuit 23.
Just tuning is determined based on N, and a frequency command signal AFRE is given to the programmable divider of the local oscillation circuit 13 so that just tuning can be obtained. Note that the programmable divider of each local oscillation circuit 13, 14 is configured to take in the frequency command signal AFRE based on the strobe signals STR1, 5TR2.

In this embodiment, the tuning operation is performed one by one for the audio channels in the transmission mode using two subcarrier signals, and when just tuning is obtained for the - side, the local oscillation of the second series is performed. The frequency command signal AFRE for the circuit 14 is fixed, and then the first series is used to perform a tuning operation on the other subcarrier signal component.

In practice, the center frequencies of the audio intermediate frequency signals AIFI and AlF2 are set to 10.
7 (Mllz), and the tuning operation is performed to satisfy this.

Note that since the center frequency of the audio intermediate frequency signals AIFI and AlF2 is 10.7 (MHz), the center frequency of the pass band of the band pass filters 15 and 16 is also 10.7 (MHz).
7 (M)lz). Also, depending on the transmitted audio signal, the audio band (deviation due to FM modulation) may be wide or narrow; The band can be switched.

Further, the controller 3 has a built-in automatic tuning processing program shown in FIG. 2, and performs automatic tuning operation using the audio map MAP shown in FIG. 3 and according to the processing procedure.

Here, the audio map MAP includes the stereo broadcast transmission mode MODE, the first subcarrier signal frequency FREQI, and the second subcarrier signal frequency FR for the receivable stereo broadcast audio channels.
EQ2 and bandwidth width information BAND are stored with identification numbers assigned to each audio channel.

In the case of this embodiment, the audio map MAP is formed so that audio channels with the same transmission mode (in the map of Fig. 3, multiplex mode and monaural mode are stored as the same mode) are continuous. Furthermore, for audio channels in the same transmission mode, the more frequently broadcast the audio channel is, the smaller the identification number NO is stored in the area.

Furthermore, the audio map MAP has an empty area as a user area at the time of shipment.

Note that if the broadcast channel from the artificial satellite is different (the broadcast channel is selected by the tuner section 2), the receivable audio channel will also be different, so for example, the frequency of one subcarrier signal for different audio channels may be different from the audio channel. The numbers may be the same, such as MAP numbers "2" and "3".

The controller 3 uses an audio map like this.
During the operation of automatic channel selection using , first, the program is started in step SPI, and then the process proceeds to the next step SP2, where a signal indicating that the audio mode key has been turned on arrives from the key-powered device 8. Step SP2 is repeated until the audio mode key is turned on.

If a positive result is obtained in the repeated processing of step SP2, the controller 3 proceeds to the next step SP3 and determines the selected transmission mode.

Here, the memory 9 stores information about the last channel that was selected immediately before, and the controller 3 selects the next transmission mode for the last channel according to the predetermined transmission mode change order. For example, transmission mode using one subcarrier signal (hereinafter referred to as single carrier mode), such as multiplex mode and monaural mode, discrete mode, matrix mode, single carrier mode, etc. In a case where it is determined that the mode changes in the order of one carrier mode, when an on operation of the audio mode key is sensed when the mode of the last channel is the single carrier mode, the controller 3 determines the discrete mode as the selected mode.

When the controller 3 determines that the single carrier mode is the selected mode, the controller 3 proceeds to step SP4 and supplies the mode selection circuit 20 with a mode switching signal MOD instructing the single carrier mode, and also refers to the audio map MAP to select the audio mode. After the key is turned on, any audio channel in the single carrier mode that has not yet been tuned is selected. Thereafter, the controller 3 sets each circuit based on the stored contents of the selected audio channel in step SP5. That is, the frequency FREQI of the subcarrier signal
The frequency command signal AFRE corresponding to the strobe signal 5
It is applied to the local oscillation circuit 13 at the same time as TRI, and the band selection signal W/N of the audio channel is applied to the bandpass filter 15.

Next, the controller 3 sets the IF in step SP6.
Just tuning signal JTU from count circuit 23
Take in N and determine whether it is tuned or not,
If an affirmative result is obtained, in step SP7, information on the tuned state is stored in the last channel area of the memory 9, and then the process returns to step SP2, assuming that the series of channel selection operations have been completed.

On the other hand, if a negative result is obtained in step SP6, the process proceeds to step SP8, where it is determined whether or not the tuning operation has been performed for all audio channels related to the selected mode.
Return to step 3 and proceed to the tuning operation process for the next audio channel on the audio map 0 For example, in the case of single carrier mode, the tuning operation is performed for all audio channels with identification numbers "12" to "14". Steps 5P3-3 and P4-3P5-3P6 until the process is completed.
-3P8-3P3 processing will be repeated.

In this way, the tuning operation is executed for all audio channels in the selection mode, but if tuning is not possible and a positive result is obtained in step SP8, the controller 3 proceeds to step SP9, and when the audio mode key is turned on. At the same time, a message indicating that the channel cannot be selected is displayed on the display device 6 by giving the video signal processing section 4 a display command signal NG indicating that the channel cannot be selected, and -
The series of channel selection operations is completed and the process returns to step SP2 described above.

Further, if the controller 3 determines that the selected mode is the discrete mode as a result of the determination in step SP3 described above, the controller 3 proceeds to step 5PIO, and provides the mode selection circuit 20 with a mode switching signal MOD instructing the discrete mode. Referring to the audio map MAP, select any audio channel (for example, the channel with the lowest identification number No.) in the discrete mode that has not yet been subjected to a tuning operation. Thereafter, in step SpH, the controller 3 provides the frequency command signal AFRE corresponding to the frequency FREQI of the first subcarrier signal to the local oscillation circuit 13 at the same time as the strobe signal STR1.

Next, the controller 3 proceeds to step 5P12 and performs I
Just tuning signal J from F count circuit 23
Based on TUN, determine whether or not it has been tuned,
If a negative result is obtained, the process proceeds to the above-mentioned step SP8. On the other hand, if a positive result is obtained, the process proceeds to step 5P13 in order to determine whether or not it is also possible to tune to the second subcarrier signal component. Then, the frequency command signal AFRE corresponding to the frequency FREQ2 of the second subcarrier signal is given to the local oscillation circuit 13 at the same time as the strobe signal STR1 to be taken in, and the frequency command signal AFRE corresponds to the frequency FREQ1 of the already tuned first subcarrier signal. The frequency command signal AFRE thus obtained is applied to the local oscillation circuit 14 at the same time as the strobe signal 5TR2 to be taken in therein.

Thereafter, in step 5P14, the controller 3 determines whether or not the second subcarrier signal component has been just tuned based on the just tuning signal JTUN.
7, the series of channel selection operations ends. If a negative result is obtained, the process proceeds to step SP8 described above, and the tuning operation for the next audio channel in the mode is executed.

Further, when the controller 3 determines that the selection mode is the matrix mode as a result of the determination in step SP3 described above, the controller 3 proceeds to step 5P20.
) is the same as the processing in the case screed mode (steps 5PIO to 5P14), so the explanation thereof will be omitted below.

Note that the controller 3 sends a muting command signal MUT to the muting circuit 22 from when the audio mode key is turned on until a series of channel selection operations are completed.
E is transmitted to prevent the generation of noise, etc., so as not to cause discomfort to the listener.

When a listener attempts to tune in to an audio signal using the satellite broadcast receiver having the above configuration, the listener first specifies an artificial satellite and then specifies a broadcast channel via the key manual device 8. At this time, the controller 3 directs the antenna (not shown) in the direction of the satellite, changes the channel command signal CH3E according to the specified contents, and sends out the baseband signal BB of the specified broadcast channel from the tuner section 2. .

Thereafter, the listener only has to turn on the audio mode key of the key-powered device 8. When the controller 3 senses this ON operation, it determines the selected audio mode, refers to the audio map MAP for the audio channel of the determined mode, sets the state of each circuit, and performs a channel selection operation. Thus, when tuning is obtained for any channel in the selection mode, the speaker device 7 generates sound. Note that if tuning cannot be obtained for any channel, a message to that effect is displayed on the display device 6.

If the listener finds that the generated sound is different from what he or she desires, he or she can turn on the audio mode key again. As a result, audio signals of other channels are received and sound is generated. Note that in order to receive other audio channels in the same mode, the listener is required to turn on the audio mode key three times.

Therefore, according to the embodiment described above, the automatic channel selection function can be realized by selecting the transmission mode for a plurality of audio channels having a wide variety of transmission modes.

Incidentally, it may be possible to associate a representative audio channel with a transmission mode, and then select that representative audio channel by selecting the transmission mode, but it is possible to Since the number of channels is small, it is thought that listeners will often have to reset representative audio channels, and it is difficult to say that this is a sufficient automatic channel selection function.

In addition, according to the above-mentioned embodiment, although the present invention was applied to a satellite broadcasting receiver, the present invention is not limited to this, and can be applied to various receivers as necessary.

Further, according to the above embodiment, when an audio signal of one audio channel is received, it is fixed to that channel, but the audio channel may be switched at predetermined intervals until a stop command is given from the listener. You can also do it.

Furthermore, in the above embodiment, each mode is selected by turning on one audio mode key, but a selection key may be provided for each mode to select a predetermined mode. .

H Effects of the Invention As described above, according to the present invention, various format information about the transmitted audio signal is stored in advance in the audio map, so even if there are a wide variety of transmission modes, automatic transmission can be performed. An audio signal receiver capable of performing a channel selection operation can be easily obtained.

In this way, since the transmission mode is specified and the automatic tuning operation is executed, the number of audio channels that are subject to the automatic tuning operation is limited, and the listener can quickly tune in to the desired audio channel. Can be done.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the audio signal receiver according to the present invention, FIG. 2 is a flowchart showing the automatic tuning processing procedure for the audio signal, and FIG. 3 is a memory 9.
This is a chart showing an audio map stored in . 3...Controller, 5...Audio signal processing unit, 7...Speaker device, 8...
Key human power device, 9... Memory, 11.12...
...Mix circuit, 13.14...Local oscillation circuit, 17.18...FM demodulation circuit, 19.
... Stereo decoder, 20 ... Mode selection circuit, 23 ... IFFM demodulation circuit MAP.
...Audio map.

Claims (1)

[Claims] In an audio signal receiver capable of receiving audio signals of multiple channels in multiple transmission modes, including a stereo audio signal in a transmission mode using two subcarrier signals, the audio signal of each channel is transmitted. Information on the mode and the frequency of the subcarrier signal is stored in memory in advance, and when automatic tuning mode is selected, the stored information is read from the memory for the transmission mode specified via the input device and tuning is performed. An audio signal receiver characterized in that the audio signal receiver is operated.