JPH11186926A - Broadcasting receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the time delay or advance of broadcasting to original time by thinning predetermined data among the data of the output signals of a storage part, based on the delay time at the time of switching from the output signals of a reception part to the output signals of the storage part. SOLUTION: At switching to FM broadcasting signals, a controller 9 controls the time of reading the data of the FM broadcasting signals from the storage part 4, based on the time difference of DAB signals and the FM broadcasting signals measured in a delay time measurement part 5. The read time is controlled by changing the address of the data stored in the storage part 4 based on the delay time. Thus, the FM broadcasting signals outputted from the storage part 4 and the DAB signals outputted from a first reception part 2 are outputted from a switching part 6 in a state without delay times. By controlling a read speed by the storage part 4 and performing output without the delay time to the DAB signals, even if broadcasting signals are switched, interruption or repetition or the like does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a broadcast receiving apparatus.

[0002]

2. Description of the Related Art In recent years, as disclosed in, for example, Japanese Patent Application Laid-Open No. Sho 64-60115, when it becomes difficult to receive a certain broadcast, a broadcast receiving apparatus that switches to the reception of another broadcast having the same broadcast content. Is being considered. In particular, digital audio broadcasting (DAB: Digi
In digital broadcasting such as tal Audio Broadcasting, when it becomes difficult to receive the digital broadcasting, the broadcasting is the same as the digital broadcasting and the FM (Frequency)
A broadcast receiving apparatus that switches to a second broadcast such as a Modulation (AM) broadcast or an AM (Amplitude Modulation) broadcast has been studied.

More specifically, during mobile reception of digital broadcasting, when the reception electric field strength decreases due to a change in the reception state and good reception becomes impossible, digital broadcasting (broadcasting by digital signals) is performed. If it is possible to receive a second broadcast signal (broadcast by a method other than digital broadcast, such as FM broadcast or AM broadcast) having the same content as the digital broadcast being received, using the information contained in Then, by switching from the digital broadcast to the second broadcast having the same content, interruption of broadcast reception can be prevented.

[0004] Here, in the transmission system of digital broadcasting, for the purpose of dispersing continuous burst errors that may occur during broadcasting, the digital broadcasting is divided into time-continuous fixed time units, and according to a predetermined rule. Some of them perform interleaving to rearrange and transmit. For example, in DAB, 16 frames of interleaving are performed, so that the receiving apparatus needs to perform deinterleaving of data using a 16-frame length memory.

[0005] However, in FM broadcasting or AM broadcasting without such interleaving operation, there is almost no delay from the time of reception. Therefore, information of the same content as digital broadcasting in which interleaving is performed is broadcast by FM broadcasting or AM broadcasting. In this case, the digital broadcast is output from the receiving device with a delay of the interleave delay time.

Therefore, when the received electric field strength in digital broadcasting becomes equal to or less than a certain value and an FM broadcast or an AM broadcast broadcasting the same contents is received and switched, the demodulated output is:
Since the FM broadcast and the AM broadcast precede in time, the listener cannot hear the information corresponding to the delay time. Further, when the reception state is restored and the digital broadcast can be received, if the FM broadcast or the AM broadcast is switched to the digital broadcast, information corresponding to the delay time is repeatedly output.

[0007] Further, even in digital broadcasting using a satellite, since the transmission distance is different as compared with the terrestrial wave, a delay time is generated even when switching between satellite broadcasting and terrestrial broadcasting.

As described above, digital broadcasting has different delay times depending on the broadcasting system and transmission path.
When digital broadcasting cannot be received, even if switching to another broadcasting system that broadcasts the same content, the receiving device still loses or repeats information due to delay time.
Even if the interruption of reception can be prevented, the broadcast will be unpleasant to hear.

As a means for solving the above-mentioned problem, a method of adding a delay time to a broadcast signal having the same content as that of a digital broadcast can be considered. Specifically, when switching from digital broadcasting to FM broadcasting, after receiving a broadcast having the same content as the digital broadcast and performing FM demodulation, the demodulated audio signal is converted to analog / digital (A / D: Analog / Digit).
al) The signal is converted into a digital signal by the converter and input to the storage means. The storage capacity of the storage means is determined in consideration of the dynamic range at the time of FM broadcast output, the reproduction frequency band, and the maximum delay time. For example, the number of quantization bits is 16 bits, the sampling frequency is 48 kHz, the number of channels is 2 channels, and the maximum delay is If the time is 2 seconds, it is 384 kbytes.

The time difference can be absorbed by setting the difference between the start time of writing to the storage means and the start time of reading the storage means as the time difference between the output of the receiving device between the digital broadcast and the FM broadcast. The signal delayed by the storage means is converted again into an analog signal by a digital / analog (D / A) converter.

According to these processes, when the digital broadcast is difficult to receive, the FM broadcast (second
If the broadcast can be received, the unnaturalness due to the delay time at the time of switching can be reduced. Further, when digital broadcast reception becomes possible again, switching from FM broadcast (second broadcast) to digital broadcast can be performed with less discomfort.

[0012]

However, in the above-described method, when the digital broadcast is switched to the FM broadcast (second broadcast) having the same content as the delayed digital broadcast, naturally, the original time (actual time) is changed. Broadcast) with a delay time. Due to this delay time, there is a disadvantage that information indicating time, such as a time signal, included in the broadcast is also accompanied by a delay.

Therefore, the present invention provides a digital broadcast,
Provided is a broadcast receiving apparatus capable of preventing loss or duplication of broadcast content when switching between the digital broadcast and a second broadcast having the same content, and preventing a time delay or advance of the broadcast with respect to an original time. It is intended to be.

[0014]

According to the present invention, a first receiving section for receiving a first broadcast signal based on a digital signal and a second broadcast signal having the same content as the first broadcast signal are received. A second receiving section, a storage section for storing an output signal of the second receiving section, a switching section for switching between an output signal of the first receiving section and an output signal of the storage section, and an output signal of the first receiving section. A delay time measuring unit for measuring a time difference between the output signal of the second receiving unit and a delay time of the output signal of the first receiving unit with respect to the output signal of the second receiving unit; When switching from the output signal of the receiving unit to the output signal of the storage unit, a controller having a data thinning processing unit for thinning out predetermined data among data of the output signal of the storage unit based on the delay time is provided. Features.

According to a second aspect of the present invention, there is provided a first receiving section for receiving a first broadcast signal based on a digital signal;
A second receiver that receives a second broadcast signal having the same content as the broadcast signal, a storage unit that stores an output signal of the second receiver,
A switching unit that switches between an output signal of the receiving unit and an output signal of the storage unit; and a first unit that measures a time difference between the output signal of the first receiving unit and the output signal of the second receiving unit to determine the first signal with respect to the output signal of the second receiving unit. A delay time measuring unit for determining a delay time of an output signal of the receiving unit, and controlling switching of the switching unit, and storing based on the delay time when switching from the output signal of the storage unit to the output signal of the first receiving unit. A controller provided with data insertion processing means for inserting predetermined data among the data of the output signal of the unit.

The present invention according to claim 3 provides the invention according to claim 1.
3. The broadcast receiving device according to claim 2, wherein the controller includes a minimum level detection processing unit that detects data having the lowest amplitude level among the data stored in the storage unit for each predetermined period, and the minimum level detection unit. The data thinning process or the data insertion process is performed on the data having the lowest detected amplitude level.

[0017]

FIG. 1 is a schematic block diagram showing one embodiment of a broadcast receiving apparatus according to the present invention. In FIG. 1, the broadcast receiving device 1 includes a first receiving unit 2, a second receiving unit 3, a storage unit 4, a delay time measuring unit 5, a switching unit 6, a D / A converting unit 7, a speaker 8, and a controller 9. ing. First receiving unit 2
Includes a first antenna 10, a first demodulation unit 11, a first A / D conversion unit 12, and a signal processing unit 13. The second receiving unit 3 includes a second antenna 14, a second demodulating unit 15, a second A
A / D converter 16 is provided.

In FIG. 1, a first receiving section 2 outputs a digital broadcast signal (DA) by DAB as a digital broadcast signal.
B signal). Further, the second receiving unit 3 outputs the DA
An FM broadcast signal or an AM broadcast signal is received as a second broadcast signal having the same content as the B signal. In this embodiment, it is assumed that an FM broadcast signal is received.

In the first receiving section 2 shown in FIG. 1, when the first antenna 10 receives the DAB signal, the first demodulating section 11
However, after quadrature detection of the received signal, the signal is demodulated into an I signal and a Q signal, and the first A / D converter 1
Output to 2. The first A / D converter 12 is a first demodulator 1
1 is converted into a digital signal, and a signal processing unit 13
Output to

The signal processing unit 13 includes a first A / D conversion unit 12
Performs various kinds of processing on the digital signal input from. That is, in the digitalized DAB signal, a reference symbol that is a part of the synchronization signal is subjected to a fast Fourier transform (FFT), and is correlated with known data to calculate a frequency offset signal. First demodulation unit 1
1 for automatic frequency control (AFC: Automatic Frequency
Control) Error signal.

The data is stored in F for each unit called a symbol.
An FT process is performed, and a phase difference from the immediately preceding symbol is obtained. This phase difference takes four values (two bits). In addition, the main data is deinterleaved,
An audio signal is obtained by Viterbi decoding and error correction processing.

The DAB signal includes a high-speed information channel (FIC: Fast Infor
mation channel). In this FIC, the area where the data of the selected service is located, time and date information, the contents of the service and the title are recorded. In this, frequency information (FI: Fr
In the “Equency Information”, information on other broadcasts related to the current broadcast is recorded, and includes frequency information of FM broadcasts and AM broadcasts having the same contents. Therefore, it is possible to search for and receive an FM broadcast having the same content as the digital broadcast received by FI.

In the second receiving section 3 shown in FIG.
The FM broadcast signal received by the second antenna 14 is subjected to FM demodulation processing by the second demodulation unit 15 and is converted into a baseband signal. Since the (L + R) signal and the (LR) signal are multiplexed and recorded in the baseband signal, they are converted into an L signal and an R signal by a matrix processing unit (not shown). The demodulated FM broadcast signal is supplied to a second A / D converter 1
The signal is converted into a digital signal by 6 and output to the storage unit 4. The second A / D converter 16 converts, for example, an analog signal (FM broadcast signal) into a digital signal having a sampling frequency of 48 kHz and a quantization number of 16 bits.

The first receiving section 2 receives the DAB signal, and performs demodulation processing and digital signal processing. As a result, the output signal output from the first receiving unit 2 has a time difference with respect to the time of the reception signal received by the first antenna 10 (the transmission signal transmitted by the broadcasting station). Therefore, the output signal output from the first receiving unit 2 has a time difference with respect to the time of the FM broadcast signal on which demodulation processing is performed in real time.

The storage unit 4 stores the FM received by the second receiving unit 3
In order to output the broadcast signal in accordance with the time of the DAB signal, the output time of the FM broadcast signal is delayed to match the time delay of the DAB signal output from the first receiving unit 2 described above.

For this reason, a FIFO (First-In First-Out) memory capable of independently controlling the addresses of write data and read data is used as the storage unit 4. Reading of data from the FIFO memory is performed by DA
Control is performed such that reading is performed after delaying by a delay time between the B signal and the FM broadcast signal.

The time difference between the DAB signal and the FM broadcast signal is measured by the delay time measuring unit 5. The delay time measuring unit 5 has the same content as the received DAB signal.
The broadcast signal and the broadcast signal are correlated with each other for a certain period of time, so that the difference between the time of the DAB signal output from the first receiver 2 and the time of the FM broadcast signal output from the second receiver 3 ( Delay time).

For example, the absolute value of the difference between the data of the DAB signal and the data of the FM broadcast signal in a certain period is obtained, and the sum of those values in a certain period is obtained. And DA
Similarly, while a certain period of either the B signal or the FM broadcast signal is temporally shifted, the sum of the absolute values of the certain period is similarly obtained, and when the sum is the minimum, the minimum is obtained. The time shift amount shifted up to this point is detected as a delay time. Here, when the time difference between the DAB signal and another broadcast signal having the same content is a predetermined time difference, the delay time measuring unit 5 does not need to detect the delay time, and the predetermined time difference is used as the delay time. .

The switching unit 6 includes a DAB signal, which is a digital broadcast signal received by the first receiving unit 2 and the second receiving unit 3,
It switches the broadcast signal to be output from the AB signal and the FM broadcast signal which is another broadcast having the same content. That is, when it becomes difficult to receive the DAB signal, switching is performed so as to output an FM broadcast signal having the same content as the DAB signal.
Further, when the reception of the DAB signal becomes possible, the FM broadcast signal currently received and output is switched to the DAB signal.

The D / A conversion section 7 converts the digital signal output from the switching section 6 into an analog signal and outputs the analog signal.
The analog signal output from the A conversion unit 7 is amplified by an amplifier (not shown) and output as sound by a speaker.

The controller 9 controls the switching of the broadcast signal output from the broadcast receiving device 1 based on the reception state of the DAB signal and the broadcast signal having the same content as the DAB signal, and also controls the same content as the DAB signal and the DAB signal. , And a data thinning process or a data insertion process for adjusting the broadcast signal having the delay time to the original time is controlled.

The processing operation of the broadcast receiving device 1 will be described. In the first receiving unit 2 shown in FIG.
The DAB signal received by the first A / D converter 12 is subjected to demodulation processing by the first demodulator 11 and then subjected to A / D conversion by the first A / D converter 12.
The signal is D-converted and input to the signal processing unit 13 as a digital signal. The signal processing unit 13 converts the digital signal
The B signal is subjected to deinterleaving and the like, and is output to the switching unit 6 and the delay time measuring unit 5.

On the other hand, in the second receiving unit 3, the FM broadcast signal received by the second antenna 14 is
After being subjected to demodulation processing by 5 and converted into a baseband signal, the signal is A / D-converted by the second A / D converter 16,
It is output as a digital signal from the second receiving unit 3. Second
The digitized FM broadcast signal output from the receiving unit 3 is input to the storage unit 4 as a digital signal.

The storage unit 4 sequentially stores the FM broadcast signals from the second receiving unit 3 and outputs the FM broadcast signals to the switching unit 6 and the delay time measuring unit 5 at a reading speed based on the control of the controller 9. I do.

The delay time measuring section 5 includes a DAB signal output from the first receiving section 2 and an FM signal output from the second receiving section 3.
The time difference between the broadcast signal and the broadcast signal is measured, and the delay time between the DAB signal and the FM broadcast signal is output to the controller.

The measurement of the delay time is performed by using the DA
The absolute value of the difference between the data of the B signal and the data of the FM broadcast signal is obtained, and the sum of the absolute values in a certain period is obtained.
Then, while the data is shifted in time, the sum is sequentially obtained by the same processing. When the sum is minimum, it is assumed that the DAB signal and the FM broadcast signal match, and the time lag until the sum becomes minimum is determined. Let the amount be the delay time between the DAB signal and the FM broadcast signal.

On the other hand, a DAB signal and a DA
When the FM broadcast signal having the same content as the B signal is input without a time difference, and the switching unit 6 can receive the DAB signal in the first receiving unit 2 under the control of the controller 9, the switching unit 6 converts the DAB signal into the D / A conversion unit 7 Output to

That is, the controller 9 monitors whether the DAB signal is being received by the first receiving unit 2, and when it becomes difficult to receive the DAB signal, the DAB signal is received by the second receiving unit 3 by the switching unit 6. The output is switched to the existing FM broadcast signal.
When switching to the FM broadcast signal, the time for reading the data of the FM broadcast signal from the storage unit 4 is controlled based on the time difference between the DAB signal and the FM broadcast signal measured by the delay time measuring unit 5.

Specifically, the controller 9 temporarily stores the delay time information from the delay time measuring unit 5 in a memory (not shown) in the controller 9, and stores the data written in the storage unit and the data stored in the storage unit 4. The time for reading data from the storage unit 4 is controlled so that the time difference between the data to be read becomes the delay time difference. The control of the reading time is performed by changing the address of the data stored in the storage unit 4 based on the delay time. Therefore, the FM broadcast signal output from the storage unit 4 and the DAB signal output from the first receiving unit 2 are output from the switching unit 6 without any delay time.

The FM broadcast signal is supplied to the D / A converter 7
, And output from the speaker 8. That is, since the reading speed is controlled by the storage unit 4 and the DAB signal is output with no delay time, the broadcast signal is not interrupted or repeated even when the output broadcast signal is switched by the switching unit 6. Sounds natural.

When the FM broadcast signal is received and the DAB signal can be received, the controller 9 controls the switching unit 6 to convert the broadcast signal as a signal output from the broadcast receiving apparatus 1 into an FM broadcast signal. Switch from signal to DAB signal. In such a case, as described above,
Since there is no time delay between the DAB signal and the FM broadcast signal, the broadcast signal is not interrupted or repeated,
Sounds natural.

The above processing will be described with reference to a flowchart. Here, the digital broadcast signal is a DAB signal, and another broadcast signal having the same content as the digital broadcast signal is FDA.
Let it be an M broadcast signal. FIG. 2 is a flowchart illustrating a processing operation in the broadcast receiving device of the present embodiment. In FIG. 2, the controller 9 monitors the reception state of the DAB (step 1) and determines whether there is an FM broadcast signal of the same content from the FI included in the received digital broadcast signal (step 2). If the FM broadcast signal having the same content as the DAB signal is not being broadcast, even if the reception state of the DAB signal is deteriorated, switching to another broadcast is not performed and the DAB signal is continuously output (step 3).

There is an FM broadcast having the same contents as the DAB signal,
When the second receiving unit receives the FM broadcast (step 4), it checks whether or not a delay time (for example, 0.8 seconds) between the DAB signal and the FM broadcast signal is set in advance (step 5).

If the delay time is set in advance, the time for reading data from the storage unit is set based on the delay time (step 6). If the delay time is not set in advance (step 5), the delay time
The delay time between the signal and the FM broadcast signal is measured (step 7), and the time for reading data from the storage unit is set based on the measured delay time (step 6).

The controller 9 monitors the reception state of the DAB signal and determines whether the reception of the DAB signal is difficult (step 8). If it is not difficult to receive DAB, DA
The output of the B signal is continued (step 9), and the monitoring of the DAB reception state is continued.

When it is difficult to receive the DAB (step 8), the FM broadcast signal is output by switching to the FM broadcast signal. When the DAB can be received, the FM broadcast signal is switched to the DAB signal. , A switching process between the DAB signal and the FM broadcast signal is performed (step 10).

Next, the switching process between the DAB signal and the FM broadcast signal will be described. According to the above-described process, the DAB signal and the FM broadcast signal are received, and the DAB signal and the FM broadcast signal are switched according to the reception state of the DAB signal.
The DAB signal or the FM broadcast signal output from the broadcast receiving device 1 is the time (real time) of the broadcast signal transmitted from the broadcast.
, The time information such as a time signal in the broadcast is also delayed.

Therefore, when the output of the DAB signal and the output of the FM broadcast signal are switched, the time information in the broadcast is adjusted to the real time. Data is inserted, and after a certain period of time, a process of matching the broadcast signal with the real time is performed. Here, in DAB, the broadcast signal is a digital signal, and it is known that a delay time (0.8 seconds) occurs in the broadcast signal due to signal processing after the broadcast signal is received by the receiving device. Therefore, the time signal or the like in DAB is transmitted earlier by the time when the delay occurs on the broadcast station side in advance.

Switching from the DAB signal to the FM broadcast signal and switching from the FM broadcast signal to the DAB signal will be described. FIG. 3 is a flowchart illustrating a process of matching a broadcast signal with real time in the broadcast receiving device of the present embodiment. When the DAB signal is switched to the FM broadcast signal (step 11), and the FM broadcast is output, the FM broadcast signal is delayed in time so that the DAB signal is smoothly switched.

Therefore, after the switching, a part of the data of the FM broadcast signal output from the storage unit 4 is thinned out, and a process of adjusting the FM broadcast signal to real time is performed (step 12). The process of thinning the data is performed by the delay time
The controller 9 controls reading of data from the storage unit 4 based on the delay time temporarily stored in the controller 9 and thins out the data.

More specifically, the read address of the storage unit 4 is subtracted for at least one sample at regular intervals. The thinning interval is determined based on the time until all the delay time is absorbed, the broadcast content, or data that is hardly perceived by the listener. For example, in the case where 48 kHz sampling is stored in the storage unit 4, if data of one sample is thinned out of 40 samples, the data is thinned out at a rate of 2.5%, and 97.5% of the whole is output as a broadcast signal. You. That is, when the delay time between the DAB signal and the FM broadcast signal is 0.8 seconds, the delay time can be absorbed in 32 seconds.

After the data is thinned out in this way to absorb the delay time between the FM broadcast signal and the real time (step 1).
3), the controller stops the thinning process of the data based on the read address from the storage unit 4 and outputs an FM broadcast signal having no time delay with respect to real time (step 14).

While the FM broadcast signal is being output, the controller monitors whether DAB can be received and output (step 15). When the DAB signal becomes receivable, the output FM
The broadcast signal must be delayed again to match the time in the DAB signal.

At this time, the data is inserted into a part of the data of the FM broadcast signal read from the storage unit 4 so that the FM broadcast signal being output is not interrupted and switched to the DAB signal smoothly. The time is adjusted (step 16). For data insertion, the immediately preceding data is repeatedly read, that is, the same data as the immediately preceding data is read and data is inserted. Alternatively, the average of the values of the immediately preceding data and the immediately following data may be calculated, and the value obtained as a result of the calculation may be inserted as data.

Specifically, in a state where the FM broadcast signal is received and output from the storage unit 4, at least one sample of data is inserted at regular time intervals. Assuming that the insertion interval is performed at the same ratio as the data thinning process,
Data is inserted by repeatedly reading the read address of the data read by the storage unit 4 at a rate of 1 sample out of 40 samples. In this case as well, data is inserted at a rate of 2.5% as in the case of the data thinning process. If the delay time is 0.8 seconds, the data is inserted in 32 seconds.
The FM broadcast signal will match the DAB signal.

After data is inserted in this way to absorb the time difference between the DAB signal and the FM broadcast signal (step 1).
7), the controller stops the data insertion process based on the read address from the storage unit 4 (step 18),
A DAB signal delayed in time with respect to real time is output (step 19).

By the above processing, the switching between the DAB signal and the FM broadcast signal can be smoothly performed, and the time of the time signal or the like in the DAB and the time of the FM broadcast signal can be output without delay with respect to the real time. it can.

By performing the above-described data thinning-out processing or data insertion processing in a portion that is difficult for the listener to perceive, the broadcast signal can be switched more smoothly without a sense of discomfort. That is, in the data thinning process and the data inserting process, by using a sample having the lowest output level during a certain period in the broadcast signal, the data thinning and the data insertion are hardly perceived by a listener.

That is, when data is stored in the storage unit 4, the amplitude level of the data is monitored, and a sample having the lowest output level is thinned out during a fixed period, or data is inserted by repeatedly outputting. When switching from the DAB signal to the FM broadcast signal, the data is thinned out by not reading out the minimum level data stored in the storage unit 4 under the control of the controller. Also, when switching from the FM broadcast signal to the DAB signal, data is inserted by repeatedly reading the minimum level data stored in the storage unit 4 under the control of the controller.

FIG. 4 is a flowchart showing the minimum level detection processing of the data thinning processing or the data insertion processing in the broadcast receiving apparatus of this embodiment. This minimum level detection process is a process performed between steps 11 and 12 and steps 15 and 16 in FIG.

In FIG. 4, first, a data sample i
Is set to 0, and the initial value of the minimum amplitude level is set to the maximum value (FFFF) H of the digital data (step 20).

When the acquisition of data is started and one piece of data is acquired, the set number of data samples i is set to 1
It is incremented by one (step 21), and it is determined whether or not the number of samples of the acquired data is 40 (step 22). If the number of data samples is less than 40,
It is detected whether or not the amplitude level of the obtained data is smaller than the set minimum amplitude level (step 23). If the amplitude level of the obtained current data is larger than the minimum amplitude level (step 21), the minimum amplitude level is determined. Get the next data without changing the settings of.

The amplitude level of the input current data is compared with the set minimum amplitude level. If the current data amplitude level is smaller than the minimum amplitude level (step 21), the amplitude level of the current data is set to the minimum amplitude level. At the same time, the address of the current data is set as the address of the minimum amplitude level (step 24), and the next data is obtained.

Then, the number of samples i of the acquired data
Becomes 40 samples for a predetermined period of time (step 22), the address of the data of the minimum amplitude level among the data of up to 40 samples is stored as the minimum amplitude address (step 25).

The controller 9 performs the above-described data thinning processing or data insertion processing based on the minimum amplitude address. Here, in the above-described minimum level detection processing, the data of the lowest level of the amplitude level in a certain period is detected, but data of a level equal to or lower than a predetermined threshold value is detected in the certain period. You may make it.

As described above, digital broadcasting (D
AB) and a second broadcast (FM broadcast or AM broadcast) having the same contents as the digital broadcast, when it becomes difficult to receive the digital broadcast, switching to the second broadcast and receiving the digital broadcast becomes possible. In the broadcast receiving apparatus that switches from the second broadcast to the digital broadcast when the broadcast is received, the time output from the broadcast receiver is delayed from the digital broadcast that is broadcast with a delay with respect to the second broadcast that is broadcast in real time. When switching to the second broadcast, the received second broadcast is stored in the storage unit, the output time is controlled by controlling the speed of reading from the storage unit, and when the digital broadcast is switched to the second broadcast, the switching is smoothly performed. The switching can be performed without interruption of the broadcast content or without repeated output, and without any uncomfortable feeling.

Further, when the digital broadcast is switched to the second broadcast, a part of the data of the second broadcast stored in the storage unit is thinned out and read out, so that the digital broadcast is converted to the second broadcast.
After switching to the broadcast, the time delay between the second broadcast and real time can be absorbed. Therefore, for example, time information such as a broadcast time signal can be output without delay with respect to real time.

Further, when switching from the second broadcast to the digital broadcast, a part of the data of the second broadcast stored in the storage unit is repeatedly read and a part of the data is inserted, so that the digital broadcast is switched from the second broadcast to the digital broadcast. When switching to the digital broadcast, the digital broadcast and the second broadcast can be switched smoothly, and the broadcast can be switched without a sense of incongruity.

[0069]

According to the present invention, when a digital broadcast is switched between a digital broadcast and a second broadcast having the same content as the digital broadcast, the broadcast content can be prevented from being lost or duplicated. The time delay between the broadcast time and the real time can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a broadcast receiving device of the present invention.

FIG. 2 is a flowchart illustrating a processing operation in the broadcast receiving apparatus according to the embodiment.

FIG. 3 is a flowchart illustrating a process of matching a broadcast signal with real time in the broadcast receiving device of the present embodiment.

FIG. 4 is a flowchart illustrating a minimum level detection process of a data thinning process or a data insertion process in the broadcast receiving apparatus according to the present embodiment.

[Explanation of symbols]

1. Broadcast receiving apparatus, 2. First receiving section, 3. Second receiving section, 4. Storage section, 5. Delay time measuring section, 6. Switching section, 7. D / A conversion Unit, 8 speaker, 9 controller, 10 first antenna, 11 first demodulation unit, 12 first A / D conversion unit, 13 signal processing unit,
14 second antenna, 15 second demodulator, 16
Second A / D converter

Claims (3)

[Claims] 1. A first receiver for receiving a first broadcast signal based on a digital signal, a second receiver for receiving a second broadcast signal having the same content as the first broadcast signal, and an output of the second receiver. A storage unit for storing a signal; a switching unit for switching between an output signal of the first receiving unit and an output signal of the storage unit;
A delay time measuring unit that measures a time difference between an output signal of a receiving unit and an output signal of the second receiving unit to determine a delay time of the output signal of the first receiving unit with respect to the output signal of the second receiving unit; Controlling the switching of the switching unit,
A controller provided with a data thinning-out processing means for thinning out predetermined data among the data of the output signal of the storage unit based on the delay time when switching from the output signal of the reception unit to the output signal of the storage unit; A broadcast receiving apparatus characterized by the above-mentioned. 2. A first receiving section for receiving a first broadcast signal based on a digital signal, a second receiving section for receiving a second broadcast signal having the same content as the first broadcast signal, and an output of the second receiving section. A storage unit for storing a signal; a switching unit for switching between an output signal of the first receiving unit and an output signal of the storage unit;
A delay time measuring unit that measures a time difference between an output signal of a receiving unit and an output signal of the second receiving unit to determine a delay time of the output signal of the first receiving unit with respect to the output signal of the second receiving unit; While controlling the switching of the switching unit, when switching from the output signal of the storage unit to the output signal of the first receiving unit, predetermined data among the data of the output signal of the storage unit based on the delay time. A broadcast receiving apparatus comprising a controller having data insertion processing means for inserting data. 3. The broadcast receiving apparatus according to claim 1, wherein said controller detects a data having a lowest amplitude level among data stored in said storage unit for each predetermined period. A broadcast receiving apparatus comprising a detection processing means, wherein the data thinning processing or the data insertion processing is performed on data having the lowest amplitude level detected by the minimum level detection means.