JP2002016851A - Digital broadcast receiver and television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcast receiver which can be used comfortably by guiding the state of modulation system to a user upon receiving digital broadcast. SOLUTION: In a satellite broadcast receiving system 1 where broadcast radio wave of BS digital broadcast received by a BS antenna 2 is demodulated by a tuner box 3 to generate a video signal and an audio signal and video and audio are outputted from a television receiver 4, a message for guiding change of modulation system is presented on a display 41 when detected by extracting information concerning to the modulation system of broadcast radio wave received by the BS antenna 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiving apparatus for viewing BS digital broadcasts, and a television receiver.

[0002]

2. Description of the Related Art In general, it is difficult to view a television broadcast unless the reception state of a broadcast wave is stable at a predetermined reception intensity or higher. For this reason, channels that can be viewed may be limited, and a device that displays a reception state on a screen has been proposed.

[0003] For example, Japanese Patent Application Laid-Open No. 63-179670 discloses that the field strength level of the broadcast radio wave of each channel is determined, and the determination result is displayed on a screen together with the television broadcast so that the viewable channel is provided to the user. An apparatus for notifying is disclosed.

Japanese Patent Laid-Open No. 4-86196 discloses that
2. Description of the Related Art There is disclosed a television receiver that detects a reception state of a broadcast wave and displays a detection result on a screen.

Further, Japanese Patent Application Laid-Open No. 9-9157 discloses that
In a video signal processing apparatus corresponding to an EDTV video signal and another video signal, a video signal processing for outputting to a monitor as an OSD (On Screen Display) signal whether an input video signal is an EDTV video signal or not. An apparatus is disclosed.

Japanese Utility Model Publication No. 3009903 discloses a television receiver capable of easily detecting a reception state.

[0007]

By the way, in BS digital broadcasting which is scheduled to be put into practical use, a plurality of types of modulation schemes are to be adopted. These modulation schemes are switched according to environmental conditions when a broadcast signal is transmitted from a broadcasting station to a satellite, and the amount of information that can be transmitted and the conditions that can be handled are different from each other.

[0008] When the modulation method of the BS digital broadcast is appropriately switched, the image quality on the television receiver side changes. For example, when broadcasting is performed by a modulation method with a small amount of transmission information, the image quality of an image seen by a user is relatively low.

[0009] Therefore, the image quality on the user side is degraded or improved by switching the modulation method on the broadcast station side, so that the user may be suspected of a failure of the television receiver or the tuner, which may cause anxiety or discomfort. there were. In particular, if the user views continuously for a long time, the switching of the modulation method may occur, and a countermeasure is required.

An object of the present invention is to provide a digital broadcast receiving apparatus which can be used comfortably by guiding a user of a state of a modulation system at the time of receiving a digital broadcast.

[0011]

The present invention has the following features in order to solve such a problem. In the following description of the means, a configuration corresponding to the embodiment is shown by parentheses as an example. Reference numerals and the like are reference numerals and the like in the drawings described later.

According to a first aspect of the present invention, there is provided a digital broadcast receiving apparatus for receiving a digital broadcast signal and generating a signal for outputting video and audio included in the broadcast signal (for example, as shown in FIG. 2). In the tuner box 3), detecting means (for example, steps S1 to S5 in FIG. 3) for detecting that the modulation scheme when the broadcast signal is modulated has changed from the modulation scheme of the broadcast signal that has been input so far. And a notifying unit (for example, a CPU 301 performing the process shown in step S6 in FIG. 3) for notifying that a change in the modulation scheme has been detected by the detecting unit. I do.

According to the first aspect of the present invention, in a digital broadcast receiving apparatus that receives a broadcast signal of a digital broadcast and generates a signal for outputting video and audio included in the broadcast signal, When the detecting means detects that the modulation method at the time of the modulation has changed from the modulation method of the broadcast signal input so far, the notifying means notifies the effect.

Therefore, when the modulation system changes while the digital broadcast is being received and the image quality of the image displayed on the display screen changes, the change of the modulation system is notified by the notification means. The user is not suspected of malfunction of the device, and does not feel uneasy or uncomfortable. This makes it possible to provide a digital broadcast receiving apparatus that maintains the comfort during use even when viewing digital broadcasts for a long time.

According to a second aspect of the present invention, in the digital broadcast receiving apparatus according to the first aspect, the broadcast signal is a broadcast signal in a BS digital broadcast.

According to the second aspect of the present invention, since the digital broadcast receiving apparatus receives a broadcast signal in BS digital broadcast, it is possible to use three types of BPSK, QPSK, and TC8PSK.
The switching of the modulation method is detected as described above, and the user is notified. Thereby, even if a change in image quality occurs, the user is not suspicious of a failure of the device and does not feel uneasy or uncomfortable, so that comfort during use can be maintained.

The third aspect of the present invention is the first or second aspect.
In the digital broadcast receiver according to the aspect, the detecting unit may detect a change in the modulation scheme based on information (for example, TMCC) extracted from the broadcast signal and indicating a change in the modulation scheme of the broadcast signal. It is characterized by.

According to the third aspect of the present invention, the detecting means detects a change in the modulation scheme based on information extracted from the broadcast signal and indicating a change in the modulation scheme of the broadcast signal.

Therefore, for example, a change in the modulation scheme is detected based on information for changing the demodulation scheme in accordance with a change in the modulation scheme, such as TMCC in BS digital broadcasting. There is no need to perform special processing or the like as compared with the apparatus, and the apparatus can be realized at low cost.

According to a fourth aspect of the present invention, in the digital broadcast receiving apparatus according to any one of the first to third aspects, the notification means includes a predetermined guidance display (for example, FIG. 4 (a) and a level guide display B shown in FIG. 4 (b).

According to the fourth aspect of the present invention, the notifying means outputs a predetermined guidance display together with the video included in the broadcast signal. Therefore, when the image quality changes due to a change in the modulation method, the notification means promptly informs the user. A notification is sent to. Therefore, anxiety and discomfort of the user can be easily and reliably prevented.

According to a fifth aspect of the present invention, there is provided a television receiver (eg, a television receiver) which receives a broadcast signal of a digital broadcast and displays an image included in the broadcast signal on a display screen (eg, a display 502 shown in FIG. 5). In the television receiver with built-in tuner 5) shown in FIG. 5, a detecting means (for example, detecting that the modulation method when the broadcast signal is modulated has changed from the modulation method of the broadcast signal that has been input up to now). A display control means (for example, CPU 301 shown in FIG. 5) for displaying a predetermined guidance display on the display screen when the detection means detects that the modulation method has changed. , Is provided.

According to the fifth aspect of the present invention, in a television receiver for receiving a broadcast signal of a digital broadcast and displaying an image included in the broadcast signal on a display screen, a modulation method when the broadcast signal is modulated However, when the detection means detects a change from the modulation method of the broadcast signal input so far, the display control means causes a predetermined guidance display to be displayed on the display screen.

Therefore, when the modulation method changes while displaying the image of the digital broadcast and the image quality of the image changes,
Since the information indicating that the modulation method has been changed is displayed as a guide, the user is not suspicious of a failure of the device and does not feel uneasy or uncomfortable. This makes it possible to provide a television receiver that maintains comfort during use.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[First Embodiment] FIG. 1 is a diagram showing a configuration of a satellite broadcast receiving system 1 according to a first embodiment of the present invention. As shown in FIG. 1, the satellite broadcast receiving system 1 includes a BS antenna 2, a tuner box 3
And the television receiver 4.

The BS antenna 2 is a satellite dish receiving parabola antenna installed at an angle suitable for a predetermined broadcast satellite, and outputs a received broadcast signal to the tuner box 3.

The tuner box 3 includes a television receiver 4
And generates a video signal and an audio signal from a broadcast signal input from the BS antenna 2 and outputs the video signal and the audio signal to the television receiver 4.

The television receiver 4 includes a display 41 and a speaker 42. The television receiver 4 displays an image on the display 41 based on a video signal input from the tuner box 3, and also outputs an audio signal input from the tuner box 3. Then, the sound is output from the speaker 42.

FIG. 2 is a block diagram showing the internal circuit configuration of the satellite broadcast receiving system 1. As shown in FIG. Hereinafter, each part of the satellite broadcast receiving system 1 will be described in detail with reference to FIG.

As shown in FIG. 2, the tuner box 3 includes a CPU (Central Processing Unit) 301, a memory 302, an I / O unit 303, an input unit 304, and a modem 30.
5 are provided. In the present embodiment, these units are collectively referred to as a control system, and this control system is connected to other units described later via a bus 306.

The tuner box 3 includes a filter 307, an amplification circuit 308, a mixing circuit 309, and an oscillator 31.
0, PLL (Phase Locked Loop) circuit 311, IQ demodulation circuit 312, A / D (Analog / Digital) converter 3
13, nPSK demodulation circuit 314, TMCC decoder 31
5, descrambling unit 316, TS data separation unit 31
7, MPEG2 video decoder 318, MPEG2 audio decoder 319, video memory 320, screen processing circuit 321, D / A (Digital / Analog) converter 32
2 and the like.

The CPU 301 reads and executes the system program stored in the memory 302 to control each part of the tuner box 3 so as to control the video signal and the audio signal based on the broadcast signal input from the BS antenna 2. A signal is generated and output to the television receiver 4.

More specifically, the CPU 301
When a predetermined channel of the BS digital broadcast is designated by the instruction input from the PLL circuit 3, the PLL circuit 311
Output a control signal to set a frequency tuned to the broadcast wave of the designated channel. Thus, the video signal and the audio signal being broadcast on the designated channel are obtained by the respective units of the filter 307 to the D / A converter 322.

The CPU 301 determines from a broadcast state TMCC decoder 315 described later whether or not the demodulation method specified by the TMCC signal has been changed. When the modulation method is changed, the CPU 301
A control signal is output to the K demodulation circuit 314 to switch the modulation system, and display information for displaying a guide display to that effect on the display 41 is generated and output to the screen processing circuit 321 to be transmitted to the television receiver 4. And output a video signal including a guidance display.

In BS digital broadcasting, BPSK (Binary
Phase Shift Keying), QPSK (Quadrature Phase)
Shift Keying), TC8PSK (Trellis coded 8 Ph)
Three kinds of modulation schemes of aseShift Keying (trellis coded 8PSK) are adopted. Of these modulation schemes, T
According to the C8PSK method, broadcasting can be performed with the best image quality, and thereafter, the image quality decreases in the order of QPSK and BPSK. However, the TC8PSK method is relatively vulnerable to noise and is difficult to use unless conditions such as weather are favorable. On the other hand, the BPSK method has an advantage that it can be used even under bad conditions with much noise.

As described above, the above-mentioned three types of modulation schemes are switched and used in the terrestrial broadcasting station depending on whether the conditions for transmitting the broadcast signal from the terrestrial broadcasting station to the broadcasting satellite are good or not. Therefore, the tuner box 3 needs to be able to use a demodulation method suitable for the above three types of modulation methods, and it is necessary to switch between these three types of demodulation methods.

For this reason, the CPU 301 executes nP
The SK demodulation circuit 314 extracts a TMCC indicating the modulation scheme from the broadcast signal, and the TMCC decoder 315 decodes the TMCC to specify the current modulation scheme, and outputs a control signal to the nPSK demodulation circuit 314 to output the control signal. Is switched to the demodulation method corresponding to the modulation method.

The CPU 301 performs various processes according to an input signal from an external device connected to the I / O unit 303, and transmits data to a predetermined communication destination by input from the input unit 304. , And drives the modem 305 to execute communication with a predetermined communication destination via a communication line.

The memory 302 stores various programs executed by the CPU 301 and data relating to these programs.

The I / O unit 303 includes a tuner box 3
And a connector for connecting various external electronic devices such as video devices.

The input unit 304 includes various switches such as a power switch, and generates an operation signal indicating the content of the operation in accordance with a user operation, and outputs the generated operation signal to the CPU 301.
The input unit 304 may include an IR device for performing infrared communication with a remote controller (not shown).

The modem 305 is a device for performing data communication via a public telephone line network, for example, and is connected to a communication line as shown in FIG.

Next, each unit connected to the control system will be described.

The filter 307 is a filter that passes only a signal in a predetermined frequency band. The amplification circuit 30
Reference numeral 8 denotes an amplifier that amplifies a signal that has passed through the filter 307, and may amplify a signal in a specific frequency band.

The oscillator 310 generates an oscillating signal of a predetermined frequency under the control of the PLL circuit 311.
09 is output. The PLL circuit 311 is connected to the bus 306, and controls the oscillator 3 under the control of the CPU 301.
10 adjusts the oscillation frequency of the oscillation signal output. The mixing circuit 309 converts the frequency of the signal input from the amplification circuit 308 into an intermediate frequency signal based on the oscillation signal input from the oscillator 310, and
Output to

Therefore, the filter 307 and the amplifier circuit 30
8, mixing circuit 309, oscillator 310 and PLL circuit 31
By 1, a broadcast signal of a predetermined channel is extracted from broadcast signals received by the BS antenna 2 and output as an intermediate frequency signal.

In the IQ demodulation circuit 312, the mixing circuit 309
Demodulates the signal input from the I, the I (In-phase) signal and Q
(Quadrature-phase) signal and outputs it to the A / D converter 313.

The A / D converter 313 samples the I and Q signals input from the IQ demodulation circuit 312, converts them into digital signals, and outputs the digital signals to the nPSK demodulation circuit 314.

The nPSK demodulation circuit 314 extracts a TMCC indicating a modulation scheme from the I signal and the Q signal input from the A / D converter 313 and outputs the TMCC to the TMCC decoder 315. Then, the nPSK demodulation circuit 314
Modulates the I signal and the Q signal while appropriately switching the demodulation method in accordance with the control signal input from the CPU 301, and outputs the modulated signal to the descrambling unit 316.

The TMCC decoder 315 decodes the TMCC input from the nPSK demodulation circuit 314,
Output to PU301.

In the descrambling unit 316, nPSK
If the signal demodulated by the demodulation circuit 314 has been subjected to scramble processing, this signal is released and output to the TS data separation section 317.

The TS data separation unit 317 extracts a signal related to video from the signal descrambled by the descrambling unit 316 and outputs the signal to the MPEG2 video decoder 318, and also extracts a signal related to audio and outputs the signal related to audio to the MPEG2 audio decoder. 319.

The MPEG2 video decoder 318 utilizes a work area provided in the video memory 320 to
The signal input from the TS data separation unit 317 is MPEG
Video data is generated by decoding according to the two methods, converted into a video signal suitable for the television receiver 4, and output to the screen processing circuit 321.

In the screen processing circuit 321, the video signal input from the MPEG2 video decoder 318 and the CPU 3
The display information is synthesized with the display information input from 01 and output to the television receiver 4.

The MPEG2 audio decoder 31
9 represents a signal input from the TS data separation unit 317 as M
The audio data is generated by decoding according to the PEG2 method, and output to the D / A converter 322.

In the D / A converter 322, MPEG2
An audio signal is generated by converting the audio data input from the audio decoder 319 into an analog signal,
Output to the television receiver 4.

Next, the configuration of the television receiver 4 will be described. The television receiver 4 includes a control device 401, a display control unit 402, an audio control unit 403, and a terrestrial tuner 40.
4, a display 41, and a speaker 42, and the terrestrial tuner 404 is connected to the terrestrial broadcast antenna 2a.

The terrestrial broadcast antenna 2a is an antenna for receiving an analog broadcast signal based on terrestrial waves.
In addition, the terrestrial tuner 404 outputs the control device 4 from the broadcast signals received by the terrestrial broadcast antenna 2a.
The video signal and the audio signal included in the broadcast signal of the channel designated by 01 are extracted and output to the control device 401.

When the TV receiver 4 outputs BS digital broadcast video and audio, the control device 401
The video signal input from the screen processing circuit 321 of the tuner box 3 is output to the display control unit 402,
An audio signal input from the D / A converter 322 is output to the audio control unit 403. When outputting video and audio of terrestrial broadcasting, control device 401 outputs a video signal and an audio signal input from terrestrial tuner 404 to display control unit 402 and audio control unit 403.

The display control unit 402 controls the driving of the display 41 based on the video signal input from the control device 401, and causes the display 41 to output the broadcast video. Further, the audio control unit 403 controls the driving of the speaker 42 based on the audio signal input from the control device 401, and causes the speaker 42 to output the broadcast audio.

That is, in the tuner box 3,
Of the broadcast signal input from the BS antenna 2, only a signal in a predetermined frequency band passes through the filter 307 and is amplified by the amplifier circuit 308. Thereafter, the mixing circuit 30
9, the oscillator 310 and the PLL circuit 311, the CPU
Only the broadcast signal of the channel designated by 301 is extracted and amplified, and is output as an intermediate frequency signal to the IQ demodulation circuit 31.
2 is input.

The signal input to the IQ demodulation circuit 312 is
The signal is separated into a signal and a Q signal, and is converted into digital data by an A / D converter 313. Then, nPSK
The TMCC is extracted by the demodulation circuit 314, and the TMCC is extracted.
CPU 30 after being decoded by decoder 315
1 is output.

When the CPU 301 determines the demodulation method based on the TMCC from the TMCC decoder 315, demodulation is performed by the nPSK demodulation circuit 314 according to this demodulation method, and the demodulated signal is input to the descrambling unit 316. You. In the descrambling unit 316,
The scramble applied to the signal is released, the signal related to the video is output to the MPEG2 video decoder 318 in the TS data separation unit 317, and the signal related to the audio is
Output to the PEG2 audio decoder 319.

The signal input from the TS data separation unit 317 by the MPEG2 video decoder 318 is MP
Video data is generated by decoding according to the EG2 method, and output to the screen processing circuit 321 as a video signal suitable for the television receiver 4. Then, the screen processing circuit 321
Then, the video signal input from the MPEG2 video decoder 318 and the display information input from the CPU 301 are combined and output to the television receiver 4.

The MPEG2 audio decoder 31
In 9, the signal input from the TS data separation unit 317 is decoded according to the MPEG2 system to generate audio data, and is output to the D / A converter 322. In the D / A converter 322, the audio data input from the MPEG2 audio decoder 319 is converted into an analog signal to generate an audio signal.
Output to

Accordingly, the video and audio of the digital broadcast received by the BS antenna 2 are output by the television receiver 4.

Next, the broadcast state display processing in the satellite broadcast receiving system 1 configured as described above will be described with reference to FIG.
This will be described with reference to FIG. First, the CPU 301
When the TMCC decoded by the decoder 315 is input (step S1), it is checked whether or not the TMCC includes information for instructing a change in modulation scheme (step S2).

If the TMCC does not include the information instructing the change of the modulation scheme (step S3; N
o), the CPU 301 returns to step S1. Also, TM
If the CC includes information instructing the change of the modulation scheme (step S3; Yes), the CPU 301
Confirm information about modulation scheme in CC (step S
4).

Here, when the modulation method specified by the information in the TMCC has not been changed (step S5;
No), the process returns to step S1. If it is confirmed from the information on the modulation scheme in the TMCC that the modulation scheme has been switched (Step S5; Yes), display information for displaying information indicating the switching of the modulation scheme on the display 41 is generated. Then, the output is output to the screen processing circuit 321 (step S6), and thereafter, the process returns to step S1.

Here, an example of guidance display on the display 41 is shown in FIG. FIG. 4 is a diagram illustrating an example of a screen displayed on the display 41. FIG. 4A illustrates a broadcast screen 41a, and FIG. 4B illustrates a broadcast screen 41b. A level guidance display A is displayed on the broadcast screen 41a shown in FIG. In the level guidance display A, the modulation method of the broadcast wave is expressed as “reception state”, and is expressed as “level” which is easy for the user to understand.

For example, if the modulation method is TC8PSK to QP
When switching to SK, the conditions between the terrestrial broadcasting station and the satellite are poor, and high-quality broadcasting cannot be performed. Therefore, the switching of the modulation method is perceived by the user as a change in image quality. By guiding the “level” of the “reception state”, the user's anxiety can be resolved and the convenience can be improved.

On the other hand, a level guide display B is displayed on the broadcast screen 41b shown in FIG. The level guide display B expresses the switching of the modulation method as a decrease in the reception state. The level guide display B is an example in the case where the image quality is reduced due to the switching of the modulation method. When the image quality of the image on the display 41 is improved due to the switching of the modulation method, a different expression may be used.

The level guidance display A shown in FIG.
Are always displayed on the display 41 and can be used so that the expression of the level can be switched according to the switching of the modulation method. On the other hand, the level guidance display B shown in FIG.
Is suitable when the modulation method is switched and displayed on the display 41 for a predetermined time.

Therefore, in the satellite broadcast receiving system 1, when the modulation method of the broadcast wave received by the BS antenna 2 is switched, the display 41 displays
A display to that effect is displayed. For this reason, even if the image quality of the image on the display 41 changes due to the switching of the modulation method, the user may be suspicious of the failure of the satellite broadcast receiving system 1 or may have a feeling of distrust or discomfort. There is no. Thereby, the satellite broadcast receiving system 1 that can be used comfortably can be provided.

In the above-described first embodiment, the configuration in which the BS antenna 2 of the parabolic antenna is used has been described. However, the present invention is not limited to this. The broadcast signal may be input to the tuner box 3 by a cable branched from the antenna, or the broadcast signal may be input to the tuner box 3 via a cable such as a cable television.

Further, in the first embodiment, the level guide display A and the level guide display B are displayed on the display 41. However, the present invention is not limited to this. Tuner box 3
A plurality of LEDs are arranged in an outer case of
By switching the lighting state of the ED, the switching of the modulation method of the broadcast wave received by the BS antenna 2 may be notified.

The satellite broadcast receiving system 1 is not limited to the BS digital broadcast, but may be a system for receiving a terrestrial digital broadcast. In addition, specific details such as the size of the display 41 can be appropriately changed. Of course, it is.

[Second Embodiment] Subsequently, a television receiver 5 with a built-in tuner according to a second embodiment of the present invention will be described.
Will be described. The TV receiver 5 with a built-in tuner
The tuner box 3 according to the first embodiment is built in a television receiver including a display 508 and a speaker 510. Therefore, for the portion having the same configuration as that of the first embodiment,
The same reference numerals are given and the description is omitted.

The display control unit 501 also controls the display 5 based on the video signal input from the screen processing circuit 321.
02 on the screen of the display 502 by driving and controlling
Display BS digital broadcast video. Voice control unit 50
Reference numeral 3 controls the drive of the speaker 504 based on the audio signal input from the D / A converter 322, and causes the speaker 504 to output the sound of the BS digital broadcast.

The CPU 301 executes the broadcast state display processing shown in FIG. Therefore, according to the television receiver 5 with a built-in tuner shown in FIG. 5, when the modulation method of the broadcast radio wave received by the BS antenna 2 is switched, a display to that effect is displayed on the display 502. For this reason, even if the image quality of the image on the display 502 changes due to the switching of the modulation method, the user may be suspected of the failure of the television receiver 5 with a built-in tuner, or may feel distrust or discomfort. TV receiver with built-in tuner 5
Can be provided.

Further, since the components of the CPU 301 to the D / A converter 322 are built in the television receiver 5 with a built-in tuner, the space required for installation is small, and the convenience can be improved.

[0083]

According to the first aspect of the present invention, when the modulation system changes while the digital broadcast is being received, and the image quality of the video displayed on the display screen changes, the notification unit changes the modulation system. Since the user is notified of the change, the user is not suspicious of the failure of the device and does not feel uneasy or uncomfortable. This makes it possible to provide a digital broadcast receiving apparatus that maintains comfort even when used for a long time.

According to the second aspect of the present invention, since the digital broadcast receiving apparatus receives a broadcast signal in a BS digital broadcast, it is possible to use three types of BPSK, QPSK, and TC8PSK.
The switching of the modulation method is detected as described above, and the user is notified. Thus, even if a change in image quality occurs, the user is not suspicious of a malfunction of the device and does not feel uneasy or uncomfortable, so that comfort can be maintained even during long viewing.

According to the third aspect of the present invention, for example, B
Like TMCC in S digital broadcasting, the modulation system is detected based on information for changing the demodulation system in accordance with the modulation system, so special processing is required compared to a normal digital broadcast receiver. And so on, and can be realized at low cost.

According to the fourth aspect of the present invention, when the image quality changes due to a change in the modulation method, the user is notified immediately, so that the user's anxiety and discomfort can be easily and reliably prevented. it can.

According to the fifth aspect of the present invention, when the modulation system changes while the image of the digital broadcast is displayed and the image quality of the image changes, the change of the modulation system is displayed as a guide. Therefore, the user is not suspicious of the failure of the device, and does not cause anxiety or discomfort. This makes it possible to provide a television receiver that maintains comfort during use.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a satellite broadcast receiving system 1 according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the satellite broadcast receiving system 1 of FIG.

FIG. 3 is a flowchart showing a broadcast state display process in the satellite broadcast receiving system 1 of FIG.

FIG. 4 is a diagram showing an example of a screen displayed on a display 41 of FIG. 1, wherein (a) shows a broadcast screen 41a,
(B) is a diagram showing a broadcast screen 41b.

FIG. 5 is a diagram illustrating a configuration of a television receiver with a built-in tuner 5 according to a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 satellite broadcast receiving system 2 BS antenna 2a terrestrial broadcast antenna 3 tuner box 301 CPU 302 memory 303 I / O unit 304 input unit 305 modem 306 bus 307 signal processing unit 308 multiplier 309 oscillator 310 FLL detection circuit 311 IQ separation circuit 312 A / D converter 313 nPSK demodulation circuit 314 TMCC decoder 315 Scrambler 316 TS data separator 317 MPEG2 video decoder 318 MPEG2 audio decoder 319 Video memory 320 Screen processing circuit 321 D / A converter 4 TV receiver 41 Display 42 Speaker 401 Control device 402 Display control unit 403 Audio control unit 404 Terrestrial tuner 5 TV receiver with built-in tuner 501 Display control unit 02 display 503 voice control unit 504 speakers

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 7/08 H04N 7/08 Z 7/081 F term (Reference) 5C025 BA25 CA09 CB07 DA01 DA04 DA05 5C063 AA20 AB03 AC01 AC10 CA12 CA23 CA29 CA34 DA07 5K004 AA05 FA03 FA05 FA06 FE06 FH01 5K061 AA13 BB07 BB10 DD00

Claims (5)

[Claims] 1. A digital broadcast receiving apparatus for receiving a broadcast signal of a digital broadcast and generating a signal for outputting video and audio included in the broadcast signal, wherein a modulation method when the broadcast signal is modulated is provided. However, detecting means for detecting a change from the modulation method of the broadcast signal that has been input so far, and a notifying means for notifying that a change in the modulation method has been detected by the detecting means, Digital broadcast receiving device. 2. The digital broadcast receiving apparatus according to claim 1, wherein said broadcast signal is a broadcast signal in BS digital broadcasting. 3. The system according to claim 1, wherein said detecting means detects a change in the modulation scheme based on information extracted from the broadcast signal and indicating a change in the modulation scheme of the broadcast signal. 3. The digital broadcast receiving device according to 2. 4. The digital broadcast receiving apparatus according to claim 1, wherein said notifying means outputs a predetermined guide display together with a video included in said broadcast signal. 5. A television receiver for receiving a broadcast signal of a digital broadcast and displaying an image included in the broadcast signal on a display screen, wherein a modulation method used when the broadcast signal is modulated is the same as the input signal. Detecting means for detecting that the modulation method has been changed from the modulation method of the broadcast signal, and display control for displaying a predetermined guidance display on the display screen when the detection means detects that the modulation method has changed. Means, and a television receiver.