JP3510815B2 - Broadcast reception recording device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast receiving / recording device capable of receiving a broadcast including an audio signal and recording the received audio signal.

[0002]

2. Description of the Related Art Conventionally, when a mini disk (MD) player or a cassette tape recorder is connected to a radio broadcast receiver and a music program or news program broadcast during a certain time zone is recorded on an MD or a magnetic tape. However, when a plurality of programs and a plurality of musical pieces are continuously recorded on one track and then only a desired program or a musical piece is to be reproduced, there is a problem that it is difficult to find the beginning.

Therefore, during recording, a silent portion (between songs) in which the level of the audio signal drops to substantially zero is detected, and the track number is updated at the time of detection, so that it is easy to find the beginning of the subsequent reproduction. The proposed method has been proposed.

For example, in an MD player, as shown in FIG. 9, a lead-in portion LI and a lead-out portion L of an MD (31).
TOC information and audio signals are to be recorded in the signal recording area between O, and as the TOC information, the track number (song number) corresponding to each music, the recording start address and the recording end of each music are recorded. The address is written. Therefore, by updating the track number between songs, it is possible to easily perform the cue based on the track number.

[0005]

However, in the above track number updating system, the level of the audio signal is lowered even when the reception condition of the broadcast wave deteriorates, for example, in the peripheral portion of the broadcast service area. However, there is a risk that this may be mistaken for the position between songs, and this causes a problem that one song is divided into a plurality of tracks.

Therefore, an object of the present invention is to prevent erroneous recognition of an inter-track position due to deterioration of a reception state in a broadcast receiving / recording apparatus.

[0007]

A broadcast receiving / recording apparatus according to the present invention comprises a receiving means for receiving a broadcast including an audio signal, and a recording means for recording an audio signal obtained from the receiving means together with a track number on a recording medium. A control means for controlling the operation of the recording means, a music interval detection means for detecting the music interval position of the audio signal obtained from the reception means, and a reception state determination means for determining the quality of the reception state by the reception means, The control means updates the track number to be recorded on the recording medium only when the inter-track position is detected by the inter-track detecting means and when the receiving condition is judged to be good by the receiving condition judging means. The inter-track detecting means detects a silent portion of the audio signal obtained from the receiving means and determines this as the inter-track position.

In the broadcast receiving / recording apparatus of the present invention, when the reception condition deteriorates, the level of the audio signal obtained from the receiving means is lowered to generate a silent portion. In this case, this silent portion is detected. Even if it is determined that it is between songs by doing so, the determination result is invalidated.

In a specific configuration, the reception state determination means determines the quality of the reception state based on the level of the reception level of the broadcast by the reception means. When the reception state deteriorates, the reception level of the broadcast by the reception means decreases, and this can be determined to be the deterioration of the reception state.

In another specific configuration, the reception state determination means determines the quality of the reception state based on the availability of the synchronization establishing operation included in the demodulation processing of the received signal.
When the reception state deteriorates, it becomes difficult to read the synchronization signal in the demodulation processing of the received signal, and synchronization cannot be established. Therefore, it can be determined that the reception state deteriorates.

In still another specific configuration, the reception state determination means determines the quality of the reception state based on the magnitude of the error rate in the error detection / correction processing of the received signal or whether or not error correction is possible. When the reception state deteriorates, the data error rate increases or the error correction becomes impossible at the time of decoding the received signal. Therefore, it can be determined that the reception state deteriorates.

[0012]

According to the broadcast receiving / recording apparatus of the present invention, erroneous recognition of the inter-track position due to the deterioration of the reception state can be prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment in which the present invention is applied to a digital audio satellite broadcast receiving / recording apparatus will be specifically described with reference to the drawings. In digital audio satellite broadcasting, it is possible to transmit a broadcasting program of many channels in one transmission frequency band having one center carrier frequency, and audio data of each channel is multiplexed by TDM (time division multiplexing) system. Then, after QPSK modulation, it is delivered to each home as one broadcast wave. In each home, the receiving device can select a desired channel.

In digital audio satellite broadcasting,
Audio data of a plurality of channels is time-division multiplexed into a TDM bit stream having a periodic frame structure as shown in FIG. Each frame is composed of a synchronization signal, a header, and a plurality of slots (1 to n), and each slot contains a predetermined number of bits of data. In addition, the header of each frame is composed of a plurality of labels (1 to n) corresponding to a plurality of slots (1 to n), and each label indicates the data of which channel the data stored in the corresponding slot is. It includes a code (channel identification data) for identifying whether or not

FIG. 6 shows a TDM bit stream when the number of slots in one frame is 7, and the label 1
~ Label 7 indicates channel identification data "A", "B", "C" of the data stored in the slots i-j,
"A", "B", "A" and "0" are written. The identification data “0” of label 7 represents an empty slot. In this example, for example, channel "A"
Means that data is transmitted using the three slots of slot 1, slot 4 and slot 6 of each frame.

Therefore, for example, when the program of channel "A" is selected, the data of slot 1, slot 4 and slot 6 are extracted from each frame of the TDM bit stream, and these data are shown in FIG. By chronologically synthesizing as shown in (1), a series of channel data forming the program of the channel "A" can be obtained.

The series of channel data thus obtained has an MPEG audio format consisting of a header, audio data and auxiliary data (ancillary data) as shown in FIG. In the header, in addition to the synchronization word, as the program-related data, the transmission bit rate,
It includes data representing the sampling frequency, monaural / stereo distinction, and the like. Further, the auxiliary data includes, as the program-related data, data representing the category of the song, the language of the song, the title of the song, and the like.

As shown in FIG. 1, the receiving / recording apparatus of the present invention comprises a receiving circuit (2) having an antenna (1) for receiving digital audio satellite broadcasting, and an audio signal obtained from the receiving circuit (2). MD player (3) for recording
The microprocessor (4) for controlling the operation of the MD player (3), the reception state detection circuit (7) for detecting the reception state of the reception circuit (2), and the interval between the audio signals obtained from the reception circuit (2) An inter-track detection circuit (8) for detecting the position, an operation section (5) to be operated by the user when selecting a channel or recording a signal, and a display (6) for displaying the name of the selected channel or the name of the song.
It is equipped with The inter-track detection circuit (8) is a receiving circuit.
The silent part is detected by comparing the level of the audio signal obtained from (2) with a reference value, and the silent part is detected as the inter-track position.

As shown in FIG. 3, the receiving circuit (2) includes an RF signal selection circuit (21), a QPSK demodulation circuit (22), a TDM demodulation circuit (23), an error correction circuit (27) and an MPEG header reading circuit.
(28) and an MPEG decoding circuit (29) are connected in series. The RF signal selection circuit (21) selects a digital audio satellite broadcast wave from the radio waves received by the antenna (1) and converts it into an intermediate frequency.
PLL using a PLL circuit including a programmable frequency divider
The synthesizer system is adopted, and the reception frequency is selected by controlling the division ratio of the programmable frequency divider. The QPSK demodulation circuit (22) demodulates the baseband signal from the phase-modulated carrier.

The TDM demodulation circuit (23) is a frame synchronization circuit.
(24), a header reading circuit (25), and a channel decoding circuit (26), first, the output of the QPSK demodulation circuit (22) is supplied to the frame synchronization circuit (24), based on the synchronization signal, Frame synchronization is established. When frame synchronization is established, the header reading circuit (25) reads the header included in each frame of the TDM bitstream. Here, when the operation section (5) is operated to select a desired channel, the channel decoding circuit (26) extracts the data contained in the slot containing the data of the selected channel. Data are combined in time series to reconstruct a series of channel data.

The channel data obtained from the TDM demodulation circuit (23) is error-corrected by the error correction circuit (27),
Next, after the MPEG header is read by the MPEG header reading circuit (28), it is supplied to the MPEG decoding circuit (29) and subjected to MPEG decoding. The audio signal thus obtained is output to the MD player (3) as shown in FIG.

FIG. 2 shows a specific configuration of the reception state detection circuit (7). The signal obtained from the output terminal of the RF signal selection circuit (21) is used as an input signal for smoothing the input signal. And a pair of voltage dividing resistors R1 and R2 for dividing a predetermined power supply voltage Vcc to create a threshold voltage, and comparing the output signal of the low pass filter with the threshold value. It is equipped with a comparator (71). Here, when the reception state deteriorates, the level of the output signal of the RF signal selection circuit (21) decreases, and the signal level falls below the threshold value.
A low signal is output from the comparator (71) and supplied to the microprocessor (4). By this, the microprocessor (4) can judge the deterioration of the reception condition.

FIG. 4 shows a track number updating process executed by the microprocessor (4) in the process of recording the audio signal output from the receiving circuit (2) on the MD by the MD player (3). First, in step S1, it is determined whether or not a recording end operation is performed by the user,
If no, the process moves to step S2 and the inter-track detection circuit
It is determined by (8) whether the inter-track position is detected. If it is determined NO here, the process returns to step S1 to repeat the determination of whether or not there is an ending operation and the determination of the inter-track distance.
After that, when it is determined in step S2 that the inter-track position is detected, the process proceeds to step S3, and it is determined whether or not the reception state is good based on the signal from the reception state detection circuit (7), and the reception state is When it is determined that the track number has not deteriorated, the track number is increased in step S4. On the other hand, when it is determined in step S3 that the reception state is deteriorated, the track number is not increased and step S3 is performed.
Return to 1.

The track number updated by the above procedure is written as TOC information in MD (31) as shown in FIG. Therefore, after that, when only the desired music is reproduced from the MD by the MD player (3), a quick cue can be performed only by inputting the track number through the operation unit (5).

In the broadcast receiving / recording apparatus of the present invention, when the receiving condition deteriorates, the level of the audio signal obtained from the receiving circuit (2) lowers and a silent portion is generated. In this case, the silent portion is generated. Even if it is determined that it is between songs by detecting the portion, the determination result is ignored, so that updating of the track number due to erroneous recognition of the position between songs is prevented.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, the reception state detection circuit (7)
As shown in FIG. 2, it is not limited to the method of detecting a silent portion, but FIG.
It is possible to employ a method of judging whether frame synchronization is established in the TDM demodulation circuit (23) shown in FIG.
In this case, when the reception condition deteriorates, the pattern of the frame synchronization signal is disturbed and the frame synchronization is lost.
This can be judged as the deterioration of the reception state. Further, it is possible to judge the quality of the reception state based on the magnitude of the error rate obtained from the error correction circuit (27) or the possibility of error correction. In this case, when the reception state deteriorates, the error rate of the data exceeds a predetermined threshold value or error correction becomes impossible, so this can be determined to be the deterioration of the reception state.

Further, in detecting the inter-track position, it is also possible to adopt a method of detecting the change in the program-related data at the same time as detecting the level decrease of the audio signal. In this method, the program-related data changes even at the inter-song position where there is no silent portion, so it is possible to detect without missing the inter-song.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a broadcast receiving / recording apparatus according to the present invention.

FIG. 2 is a circuit diagram showing a specific configuration of a reception state detection circuit.

FIG. 3 is a block diagram showing a specific configuration of a receiving circuit.

FIG. 4 is a flowchart showing a track number updating procedure in the broadcast receiving / recording apparatus.

FIG. 5 is a diagram illustrating a data structure of a TDM bitstream.

FIG. 6 is a diagram illustrating an example of a TDM bitstream.

FIG. 7 is a diagram showing a configuration of channel data obtained by channel selection.

FIG. 8 is a diagram showing an MPEG audio format.

FIG. 9 is a diagram illustrating a data structure of TOC information in MD.

[Explanation of symbols]

(1) Antenna (2) Receiver circuit (3) MD player (4) Microprocessor (5) Operation part (6) Display (7) Reception status detection circuit (8) Track detection circuit

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Claims (5)

(57) [Claims] 1. A receiving unit for receiving a broadcast including an audio signal, a recording unit for recording an audio signal obtained from the receiving unit together with a track number on a recording medium, a control unit for controlling the operation of the recording unit, and a receiving unit. The inter-track detecting means for detecting the inter-track position of the audio signal obtained from the audio signal and the receiving state judging means for judging the quality of the receiving state by the receiving means are provided, and the control means detects the inter-track position by the inter-track detecting means. The broadcast receiving and recording device is characterized in that the track number to be recorded on the recording medium is updated only when the reception state determining means determines that the reception state is good. 2. The broadcast receiving / recording apparatus according to claim 1, wherein the inter-track detecting means detects a silent portion of the audio signal obtained from the receiving means and determines this as the inter-track position. 3. The broadcast receiving / recording apparatus according to claim 1, wherein the reception state determination means determines whether the reception state is good or not, depending on whether the reception level of the broadcast by the reception means is high or low. 4. The broadcast receiving / recording apparatus according to claim 1, wherein the reception state determination means determines whether the reception state is good or not based on whether or not the synchronization establishing operation included in the demodulation processing of the received signal is possible. 5. A broadcast receiving / recording apparatus, wherein the receiving condition judging means judges whether the receiving condition is good or not based on the magnitude of the error rate in the error detection / correction processing of the received signal or whether or not the error can be corrected.