CN1770837A - Broadcast receiving apparatus and broadcast receiving method - Google Patents

Abstract

Disclosed are a broadcast receiving device and a broadcast receiving method. The broadcast receiving apparatus of the present invention includes a tuning section (18) that generates an intermediate frequency signal based on an intermediate frequency setting signal from a received broadcast signal, a filter section (19) that allows the generated intermediate frequency signal to pass, a demodulation section (20) , which performs demodulation processing on the intermediate frequency signal passing through the filtering section (19) based on the intermediate frequency setting signal, and a control section (23), which, after inputting information on the location when the broadcast signal is received, reads the information stored in advance in the memory (24) ), and apply the signal to the tuning section (18) and the demodulation section (20).

Description

Broadcast receiving device and broadcast receiving method

technical field

The present invention relates to a broadcast receiving device and a broadcast receiving method for receiving, for example, analog TV broadcasts, especially a broadcast receiving device and a broadcast receiving method compatible with global broadcast programs not limited to any specific country or region.

Background technique

It is well known that due to legal restrictions, the IF frequency of tuners used for analog TV broadcasts is different depending on the country. For example, in Europe, America and Japan, the frequency is 38.9 MHz and in China and other Asian countries, the frequency is 38.0 MHz.

Therefore, generally, a tuner type for handling each available intermediate frequency is prepared, and a method of providing a machine type compatible with a target country, and a method of selling a machine type corresponding to a user's area have been adopted.

However, these methods have problems in that the tuner-to-user supply system becomes complicated and that if users bring their purchased tuners to regions with different intermediate frequencies, they cannot use the purchased tuners .

Japanese Patent Application Laid-Open Publication No. 2000-40977 discloses a frequency converter that uses a mixer to convert an intermediate-frequency TV signal to a low frequency, and Japanese Patent Application Laid-Open Publication No. 9-205593 discloses a circuit that performs digital filtering on an intermediate-frequency video signal.

However, the two publications do not describe a method with regard to the fact that the intermediate frequency has to be inconsistent to facilitate the supply of tuners to users to meet the tuners depending on the country or region.

Contents of the invention

Therefore, the present invention has been accomplished in consideration of the situation described above, and an object of the present invention is to provide a broadcast receiving device and a broadcast receiving device capable of easily handling different intermediate frequencies without support from other devices and further facilitating provision of devices to users. method, thereby promoting its practical application.

According to an aspect of the present invention, there is provided a broadcast receiving apparatus including: a receiving section configured to receive a broadcast signal; A tuning section of an intermediate frequency signal of a frequency; a filtering section configured to allow an intermediate frequency signal generated in the tuning section to pass; a demodulation section configured to perform demodulation of an intermediate frequency signal based on an intermediate frequency setting signal; a storage and receiving means configured a storage section for information on an intermediate frequency setting signal corresponding to an available area; and a control section configured to read information on an intermediate frequency setting signal corresponding to a specific area from the storage section, the specific area being selected by the user, and providing the signal to the tuning part and the demodulation part.

According to another aspect of the present invention, there is provided a broadcast receiving method including: a first step of receiving a broadcast signal; a second step of generating an intermediate frequency signal having a frequency based on an intermediate frequency setting signal from the received broadcast signal; allowing A third step of passing the generated intermediate frequency signal through a filter; a fourth step of performing demodulation processing on the intermediate frequency signal that has passed through the filter based on the intermediate frequency setting signal; and a fifth step, after inputting information on a location where a broadcast signal is received , reading the intermediate frequency setting signal corresponding to the position of the input information stored in the memory in advance, and applying the intermediate frequency setting signal during the processing of the second and fourth steps.

Description of drawings

1 is a perspective view of the appearance of a broadcast receiving device according to an embodiment of the present invention;

2 is a block diagram for explaining a signal processing system of a broadcast receiving device of an embodiment;

3 is a characteristic diagram for explaining frequency characteristics of a bandpass filter of the broadcast receiving apparatus of the embodiment;

4 is a block diagram for explaining details of a tuning section of the broadcast receiving device of the embodiment;

5 is a block diagram for explaining details of a demodulation section of the broadcast receiving device of the embodiment;

6 is a flowchart for explaining an intermediate frequency setting operation of the broadcast receiving apparatus of the embodiment;

7 is a view for explaining an example of an intermediate frequency setting screen used in an intermediate frequency setting operation of the embodiment;

8 is a block diagram for explaining a first modification of the broadcast receiving apparatus of the embodiment;

9 is a block diagram for explaining a second modification of the broadcast receiving apparatus of the embodiment;

10 is a block diagram for explaining a third modification of the broadcast receiving apparatus of the embodiment;

11 is a block diagram for explaining a fourth modification of the broadcast receiving apparatus of the embodiment;

12 is a block diagram for explaining a fifth modification of the broadcast receiving apparatus of the embodiment;

13 is a block diagram for explaining a sixth modification of the broadcast receiving apparatus of the embodiment;

14 is a view for explaining a personal computer to which the tuning module of the embodiment is applied;

FIG. 15 is a view for explaining a portable phone to which the tuning module of the embodiment is applied.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a perspective view of a broadcast receiving device 11 of the embodiment. The broadcast receiving device 11 has a thin box-shaped housing 12 that is portable.

The housing 12 of the broadcast receiving apparatus 11 has a display portion 13 and an operation portion 14 on one plane portion 12a thereon, and a connector 15 for audio output connected to an earphone or the like is provided on a side portion 12b.

FIG. 2 shows the signal processing system of the broadcast receiving apparatus 11. As shown in FIG. That is, the TV broadcast signal received by the antenna 16 combined with the housing 12 is supplied to the tuner module 17 .

The tuning module 17 has a tuning section 18 , a bandpass filter (BPF) 19 and a demodulation section 20 . Then, the tuning section 18 converts the input TV broadcast signal into an intermediate frequency (IF) signal having a predetermined intermediate frequency, and outputs to the BPF 19 .

The BPF 19 allows a modulated waveform component that satisfies the signal-to-noise ratio of the input IF signal to a certain degree to pass through and output to the demodulation section 20 . Then, the demodulation section 20 generates a baseband video signal and audio signal before demodulation from the input IF signal.

In this way, the video signal and audio signal output from the tuning block 17 are supplied to the signal processing section 21 . After converting the input video signal into a format suitable for display by the display section 13, the signal processing section 21 outputs it to the display section 13 for display.

The signal processing section 21 performs demodulation processing on the input audio signal, and then outputs it to an earphone connected through the connector 15 from the outside for audio reproduction.

All operations of the broadcast receiving apparatus 11 including the above-mentioned receiving operation are completely controlled by the control section 23 . The control section 23 includes a central processing unit (CPU) and the like, and receives operation information from the operation section 14 in order to control the corresponding section so as to reflect the content of the operation information next.

In this case, the control section 23 uses the memory section 24 . That is, the memory section 24 mainly includes a read-only memory that stores a control program executed by the CPU of the control section 23, a read-write memory that provides a work area for the CPU, and stores various information including intermediate frequency setting signal setting, control Non-volatile memory for information, etc.

Here, for example, a silicon tuner is used as the above-mentioned tuning section 18 . The tuning section 18 can selectively set the intermediate frequency of the IF signal to 38.9 MHz or 38.0 MHz based on an intermediate frequency setting signal supplied from the control section 23 through, for example, a control bus such as IIC.

For example a digitally demodulated Surface Acoustic Wave (SAW) filter is used as BPF 19. As shown in Figure 3, the BPF 19 allows IF signals with two intermediate frequencies 38.9MHz and 38.0MHz to pass.

Further, the BPF 19 is set so that its frequency characteristic has no Nyquist slope characteristic, so that the demodulation section 20 located in the latter stage can be supplied with a modulated waveform component satisfying a certain S/N ratio.

In the demodulation section 20, the internal clock is controlled so that demodulation processing of the IF signal corresponding to the intermediate frequency set by the tuning section 18 is realized by the control section 23 based on the intermediate frequency setting signal supplied through a control bus such as IIC.

Since the tuning module 17 can satisfy IF signals having two intermediate frequencies 38.0 MHz and 38.9 MHz based on the intermediate frequency setting signal output from the control section 23, the broadcast receiving apparatus 11 can be provided to users more easily, and this is suitable for practical use.

FIG. 4 shows the tuning section 18 in detail. That is, the TV broadcast signal received by the antenna 16 is supplied to the mixer 18c through the input port 18a and the gain variable amplifier 18b.

The mixer 18c converts the TV broadcast signal of 50-870MHz to 1.2GHz by mixing with the local oscillation signal output by the local oscillator 18d.

Then, the high-frequency signal output by the mixer 18c is supplied to the mixer 18f through the SAW BPF 18e. The mixer 18f converts the input high-frequency signal into an IF signal of 38.9MHz or 38.0MHz by mixing with the oscillation signal output from the local oscillator 18g.

Thereafter, the IF signal output from the mixer 18f is drawn out from the output terminal 18k via the amplifier 18h, the SAW BPF 18i, and the amplifier 18j, and output to the BPF 19.

In the local oscillators 18d, 18g, their oscillation frequency is controlled by a phase-locked loop (PLL) circuit 181, 18m. Further, the output of the reference oscillator 18n is supplied as a reference signal to these PLL circuits 18l, 18m.

The intermediate frequency setting signal output from the control section 23 is supplied to the PLL circuit 18m through the control terminal 18o. In the PLL circuit 18m, its scale ratio is changed based on the intermediate frequency setting signal supplied from the control section 23, and the frequency of the local oscillation signal output from the local oscillator 18g is changed based thereon. Thus, IF signals of 38.9 and 38.0 MHz can be selectively generated by the mixer 18f.

The gain adjustment signal output from the demodulation section 20 is supplied to the gain variable amplifier 18b through the control terminal 18p. In the gain variable amplifier 18b, its gain is changed based on the gain adjustment signal output from the demodulation section 20, and automatic gain adjustment of the tuning block 17 is performed.

FIG. 5 shows details of the demodulation section 20. As shown in FIG. The IF signal of 38.9 or 38.0 MHz output from the BPF 19 is supplied to the mixer 20c through the input terminal 20a and the amplifier 20b.

The mixer 20c converts the input IF signal into a frequency operable by a digital signal processor (DSP) 20 at a later stage by mixing with the clock signal output from the clock generating section 20d.

After passing through the BPF 20e, the IF signal output from the mixer 20c is digitized by the analog-to-digital converter 20f driven based on the clock signal output from the clock generating section 20d, and supplied to the DSP 20g.

The DSP 20g generates a gain adjustment signal to be supplied to the gain variable amplifier 18b, a baseband video signal and an audio signal based on the clock signal output from the clock generating section 20d prior to demodulation from the input IF signal.

Then, after the gain control signal is converted into an analog signal by the digital-to-analog converter 20h, it is supplied to the gain variable amplifier 18b through the output terminal 20i and the control terminal 18p of the tuning section 18.

After the video signal is converted into an analog signal by the digital-to-analog converter 20j, it is supplied to the signal processing section 21 through the output terminal 20k. Further, after the audio signal is converted into an analog signal by the digital-to-analog converter 20l, it is supplied to the signal processing section 21 through the output terminal 20m.

The clock generation section 20d generates a clock signal based on the reference oscillation signal output from the reference oscillator 20n. The intermediate frequency setting signal output from the control section 23 is supplied to the clock generation section 20d through the control terminal 20o.

Based on the intermediate frequency setting signal provided by the control section 23, the clock generating section 20d controls the frequency of the clock signal so that the analog-to-digital converter 20f and the DSP 20g can perform analog-to-digital conversion processing and processing on the IF signal of the intermediate frequency set by the tuning section 18. demodulation processing.

When a channel scan that automatically retrieves a receivable channel by continuously scanning a continuous reception frequency band is requested, whether the intermediate frequency is set to 38.9 or 38.0 MHz is set by the user.

Figure 6 shows a flowchart outlining the IF setting operation. First, if the process is started (step S1), the control section 23 determines whether channel scanning is requested in step S2, and if it is determined that channel scanning is not requested (NO), the process is terminated (step S7).

If it is determined in step S2 that channel scanning is requested (YES), the control section 23 displays an intermediate frequency setting screen on the display section 13 in step S3. The IF Setup screen lists regions and countries as shown in Figure 7.

Then, the user selects one of the listed regions and countries where the broadcast receiving apparatus 11 is used, that is, the region or country corresponding to the place where the broadcast receiving apparatus 11 is currently installed. The selection is made by moving the pointer k on the screen by operating the operation section 14, and then operating the determination key.

Thereafter, the control section 23 waits until a region or a country is selected by the user from the intermediate frequency setting screen in step S4, and if it is determined that the region or country is selected (YES), then in step S5, reads out the information corresponding to the selected region or country from the memory 24 in step S5. The intermediate frequency setting signal corresponding to the intermediate frequency of the region or country is selected and output to the tuning part 18 and the demodulation part 20 .

Thus, in the tuning module 17, the intermediate frequency thus processed is determined. If the intermediate frequency is determined in this way, the control section 23 performs channel scanning in step S6, and terminates the processing (step S7).

According to the above-mentioned embodiment, since the tuning module 17 has the capability of adapting to IF signals having two intermediate frequencies of 38.9 and 38.0 MHz based on the intermediate frequency setting signal output from the control section 23, the broadcast receiving apparatus can be easily provided to users , and the device is suitable for practical applications.

Fig. 8 shows a first modification of the above embodiment. If FIG. 8 is explained by denoting the same parts with the same reference numerals, in the tuning block 17, a BPF 19a for 38.9 MHz and a BPF 19b for 38.0 MHz are prepared. By selectively using the switches 25a, 25b according to the intermediate frequency setting signal, the necessary BPF 19a or 19b is used. Under such a configuration, the same operations as those of the broadcast receiving apparatus shown in FIG. 2 are performed, and the same effects are obtained.

Fig. 9 shows a second modification of the above embodiment. If FIG. 9 is explained by denoting the same parts with the same reference numerals, in the tuning module 17, a signal tuning circuit 26 for the frequency of the IF signal output from the tuning part 18 is connected between the tuning part 18 and the BPF 19.

That is, if a multi-wave signal is input to the tuning section 18, since the frequency band of the SAW BPF 18e is about 20 MHz, then the carrier level of the channel adjacent or next to the receiving channel is output from the tuning section 18 without being attenuated, It is then input to the demodulation section 20 through the BPF 19.

Although in the latter stage, the frequency band characteristics of the IF signal output from the tuning section 18 are determined by the preceding stage of the analog-to-digital conversion section 20f in the demodulation section 20, the carriers of adjacent channels are not attenuated in the preceding BPF 19 so many. When there is a difference in signal level between an adjacent channel and a next adjacent channel, interference occurs if the level of the received signal is low relative to an interference wave.

In order to solve this problem, by connecting a single tuning circuit 26 for the IF signal frequency between the tuning section 18 and the BPF 19, the signal levels of adjacent channels and next adjacent channels can be suppressed so that anti-interference performance can be improved.

Fig. 10 shows a third modification of the above embodiment. If Fig. 10 is explained by denoting the same parts with the same reference numerals, in the tuning module 17, a notch filter 27 is connected between the BPF 19 and the demodulation part 20, which is the channel next to the reception channel above.

If a multi-wave signal is input to the tuning section 18 as described above, since the frequency band of the SAW BPF 18e is about 20 MHz, the channel level adjacent or next to the receiving channel is output from the tuning section 18 without being attenuated, and then passed The BPF 19 is input to the demodulation section 20.

Although in the latter stage, the frequency band characteristics of the IF signal output from the tuning section 18 are determined by the preceding stage of the analog-to-digital conversion section 20f in the demodulation section 20, the carriers of adjacent channels are not attenuated in the preceding BPF 19 so many. If the input IF signal is analog-to-digital converted under such conditions, the anti-interference performance becomes deteriorated in the vicinity of the channel next to the upper reception channel by sampling distortion in the demodulation section 20 .

In order to solve this problem, by connecting a notch filter 27 between the BPF 19 and the demodulation part 20, the signal components of the second adjacent channels are suppressed, so that the anti-jamming performance can be improved.

Fig. 11 shows a fourth modification of the above embodiment. If FIG. 11 is explained by denoting the same parts with the same reference numerals, the slot filter 28, which is the channel next to the receiving channel, is connected between the tuning part 18 and the BPF 19 in the tuning module 17. With such a structure, it is possible to suppress the signal component of the channel adjacent to the reception channel above like the third improvement, and thus it becomes possible to improve the anti-jamming performance.

Fig. 12 shows a fifth modification of the above embodiment. If Fig. 12 is explained by denoting the same parts with the same reference numerals, the slot filter 28, which is the channel next to the receiving channel, is connected between the BPF 19 and the demodulation part 20 in the tuning module 17. With such a structure, it is possible to suppress the signal component of the channel adjacent to the reception channel above like the third improvement, and thus it becomes possible to improve the anti-jamming performance.

Fig. 13 shows a sixth modification of the above embodiment. If Fig. 13 is explained by denoting the same parts with the same reference numerals, the slot filters 28, 29, which are channels next to the receiving channel above, are respectively connected between the tuning part 18 and the BPF 19 in the tuning module 17 Between BPF19 and demodulation part 20. With such a structure, it is possible to suppress the signal component of the channel adjacent to the reception channel above like the third improvement, and thus it becomes possible to improve the anti-jamming performance.

The tuning module 17 described above can be applied to a wide range of application fields including a personal computer (PC) 30 as shown in FIG. 14 , a portable phone 31 as shown in FIG. 15 , and the like.

In the meantime, the present invention is not limited to the above-mentioned embodiments, but the components of the present invention can be changed within a range not departing from the gist of the present invention when implementing the present invention. Further, various types of other inventions can be constructed by appropriately combining the components disclosed in the above embodiments. For example, it is permissible to omit some components from all the components disclosed in the examples.

Claims (14)

1. A broadcast receiving device, characterized in that it comprises: a receiving section (16) configured to receive broadcast signals; a tuning section (18) configured to convert the frequency of the broadcast signal received by the receiving section (16) into an intermediate frequency signal having a frequency specified by the intermediate frequency setting signal; a filtering section (19) configured to allow passage of the intermediate frequency signal generated in the tuning section (18); a demodulation section (20) configured to perform demodulation of the intermediate frequency signal based on the intermediate frequency setting signal; a storage section (24) configured to store information of an intermediate frequency setting signal corresponding to an available area of the receiving device; and A control section (23) configured to read information of an intermediate frequency setting signal corresponding to a specific area from a storage section (24) and supply the signal to a tuning section (18) and a demodulation section (20), the specific area is selected by the user. 2. The broadcast receiving device according to claim 1, characterized in that the tuning part (18) comprises: a first converting section (18c) configured to mix a broadcast signal received by the receiving section (16) with a first local oscillation signal to convert into a signal having a frequency higher than that of the broadcast signal; a second conversion section (18f) configured to mix the signal output from the first conversion section (18c) with a second local oscillation signal to convert it into an intermediate frequency signal having a frequency lower than that of the broadcast signal; and A frequency changing section (18m) configured to change the frequency of the second local oscillation signal used in the second converting section (18f) based on the intermediate frequency setting signal. 3. The broadcast receiving device according to claim 1, characterized in that the demodulation part (20) comprises: a third converting section (20c) configured to mix the intermediate frequency signal output from the filtering section (19) with the clock signal to convert into a signal having a predetermined frequency; an analog-to-digital conversion section (20f) configured to digitize a signal output from the third conversion section (20c) based on a clock signal; a demodulation section (20g) configured to perform demodulation processing on a signal output from the analog-to-digital conversion section (20f) based on a clock signal; and A clock signal frequency changing section (20d) configured to change the frequency of the clock signal based on the intermediate frequency setting signal. 4. The broadcast receiving apparatus as claimed in claim 1, characterized in that the filtering section (19) is a SAW filter having frequency characteristics allowing intermediate frequency signals of all frequencies output from the tuning section (18) to pass, so as to satisfy predetermined signal-to-noise ratio. 5. The broadcast receiving device according to claim 1, characterized in that the filtering part (19) comprises: a plurality of filters (19a, 19b) configured to allow intermediate frequency signals of all frequencies output from the tuning section (18) to pass; and A switch (25a, 25b) configured to selectively connect a plurality of filters (19a, 19b) between the tuning section (18) and the demodulation section (20) based on the intermediate frequency setting signal. 6. The broadcast receiving device according to claim 1, characterized in that the control part (23) comprises: a display control section (23) configured to display an IF setting screen listing a plurality of regions or countries; an operation section (14) configured to select and determine a predetermined region or country on the intermediate frequency setting screen displayed based on the display control section (23); and A generating section (24) configured to generate an intermediate frequency setting signal corresponding to a predetermined region or country selected and determined through the operating section (14). 7. The broadcast receiving apparatus according to claim 1, wherein the control section (23) is configured to input information corresponding to a location when the broadcast signal is received when channel scanning is requested. 8. The broadcast receiving apparatus according to claim 1, wherein the intermediate frequency setting signal corresponds to any one of intermediate frequency signals having 38.0 and 38.9 MHz. 9. The broadcast receiving device according to claim 1, characterized in that a single tuning circuit (26) for the intermediate frequency signal generated by the tuning section (18) is connected between the tuning section (18) and the filtering section (19). ). 10. The broadcast receiving device as claimed in claim 1, characterized in that a notch filter (27) is connected between the filter part (19) and the demodulation part (20), which is next to the receiving channel. channel. 11. The broadcast receiving device according to claim 1, characterized in that a slot-shaped Filter (28, 29), which is the channel next to the received channel above. 12. A tuning module, characterized by comprising: a receiving section (16) configured to receive broadcast signals; a tuning section (18) configured to generate an intermediate frequency signal having a frequency based on an externally supplied intermediate frequency setting signal from broadcast signals received by the receiving section (16); a filtering section (19) configured to allow the intermediate frequency signal generated in the tuning section (18) to pass; and A demodulation section (20) configured to perform demodulation processing based on an externally supplied intermediate frequency setting signal on an intermediate frequency signal passing through the filtering section (19). 13. A broadcast receiving method, characterized by comprising: A first step (16) of receiving a broadcast signal; a second step (18) of generating an intermediate frequency signal having a frequency based on the intermediate frequency setting signal from the received broadcast signal; The third step of allowing the generated intermediate frequency signal to pass through the filter (19); On the intermediate frequency signal that has passed through the filter (19), a fourth step (20) of demodulation processing is performed based on the intermediate frequency setting signal; and The fifth step (23), after inputting the information about the position of receiving the broadcast signal, reads the intermediate frequency setting signal of the position corresponding to the input information stored in the memory (24) in advance, and in the second step and the fourth step ( 18, 20) to apply the IF setting signal during processing. 14. The broadcast receiving method according to claim 13, characterized in that the fifth step (23) comprises: When a channel scan is requested, a step of displaying an intermediate frequency setting screen listing a plurality of regions or countries (23, S2, S3); performing a step of selecting and determining a predetermined region or country on the displayed intermediate frequency setting screen (14, S4); and A step of generating an intermediate frequency setting signal corresponding to the selected and determined predetermined region or country (24, S5).

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