JPH0681062B2 - Receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a receiving device for satellite broadcasting or the like having a reception prohibiting function capable of prohibiting the output of a broadcast signal of a predetermined channel.

[Outline of Invention]

The present invention has a function of prohibiting the output of a broadcast signal of a predetermined channel and a receiving device having a compulsory fine adjustment means (fine tuning function) for avoiding interference with ground waves. When setting as an object of reception inhibition, the identification signal is stored in the memory in a form corresponding to the predetermined channel, and when fine tuning is performed at the time of tuning, the adjacent channel of the reception channel is based on the stored identification signal. If it is set as a prohibited channel, if it is set as a prohibited channel, the width of the frequency deviation of the fine adjustment means is narrowed to ensure that the broadcast signal of the prohibited channel is received. Is prohibited.

[Conventional technology]

Conventionally, for example, in a television device, a receiver device having a reception prohibition function that can prohibit the output of a broadcast signal of a certain channel has been proposed for educational and other reasons. As a receiving device having such a function, there is, for example, a receiving device disclosed in Japanese Patent Application No. 60-234975 proposed by the present applicant.

This receiving device includes an index signal input unit, an index signal storage unit, an index signal comparison unit, and a broadcast signal receiving unit. The index signal is registered in advance in correspondence with a predetermined channel. Only when is input, it is possible to set or cancel the prohibition of reception of a predetermined channel and to newly register an index signal so that, for example, the setting of reception prohibition is not easily canceled. It is a thing.

Further, the above-described receiving device is equipped with a function (fine tuning function) as a countermeasure for ground wave interference. This fine tuning function operates when the broadcast signal of the channel to be received and the terrestrial wave in the band close to the broadcast signal interfere with each other and good reception becomes impossible, and the AFT operation is stopped. Then, the user himself / herself forcibly shifts the tuning frequency within a range of, for example, ± 10 MHz to perform fine adjustment to avoid interference with terrestrial waves and enable good reception.

[Problems to be solved by the invention]

However, in the receiving device having the reception prohibition function and the fine tuning function, even though the reception prohibition is set for the predetermined channel, the reception prohibition is performed adjacent to the prohibited channel. There is a problem that it is possible to see the image of the channel for which reception is prohibited by setting the channel that is not in the receiving state and shifting the tuning frequency using the fine tuning function.

Therefore, it is an object of the present invention to provide a receiving apparatus in which viewing of an image of an adjacent channel is prevented by using a fine tuning function when the adjacent channel is a channel for which reception is prohibited.

[Means for solving problems]

According to the present invention, in a receiving device capable of prohibiting the output of a broadcast signal of a predetermined channel, a fine adjustment unit that shifts the tuning frequency, a memory that stores an identification signal that identifies the predetermined channel, and a tuning channel. Sometimes, by referring to the identification signal stored in the memory, it is possible to determine whether or not the adjacent channel of the receiving channel is set to output inhibition, and finely adjust when the adjacent channel of the receiving channel is set to output inhibition. Means for narrowing the width of the frequency shift of the means.

[Operation] When the predetermined channel is set as the reception prohibited target by using the reception prohibition function, an identification signal indicating the reception prohibited channel is stored in the nonvolatile memory 50 in a form corresponding to the predetermined channel. To be done. When the fine tuning function is used at the time of tuning, whether or not the adjacent channel of the receiving channel is the object of the reception inhibition is judged based on the identification signal stored in the non-volatile memory 50, and the adjacent channel is determined to be the reception inhibition. If so, the width of the frequency shift is narrowed, and the broadcast signal of the channel for which reception is prohibited is not output.

〔Example〕

An embodiment of the present invention will be described below in the following order with reference to the drawings.

a. Description of broadcast signal b. Description of reception channel selection c. Description of audio system d. Description of fine tuning function e. Description of reception prohibition function a. Description of broadcast signal Figure 1 shows 12 GHz band ku band An embodiment in which the present invention is applied to a receiver for satellite broadcasting capable of receiving the c band in the 4 GHz band will be described below.

In FIG. 1, reference numeral 11 denotes a BS antenna as an input unit for radio waves transmitted from broadcasting satellites. Ku from broadcasting satellite 10
Band (12 GHz band, 11.7 to 12.2 GHz) or c band (4
A satellite broadcast signal in the GHz band (3.7 to 4.2 GHz) is supplied to the S / U converter 12 via the BS antenna 11.

In this S / U converter 12, frequency conversion is performed, and both the ku band and the c band are converted into a signal G _{BS of} 950 to 1450 MHz. That is, the local frequency for frequency conversion in the S / U converter 12 is fixed at 10.75 GHz in the ku band, and fixed at 2.75 GHz in the c band.

In addition, although only one system of the BS antenna and the S / U converter is disclosed in FIG.
The BS antenna and S / U converter that are separate from the one used for band reception are switched and used.

The satellite broadcast signal S _BS has the highest frequency as shown in FIG.
The carrier of the 12 GHz band or the 4 GHz band is FM-modulated by a signal in which the FM audio signal S _AFM whose carrier is located in the upper frequency band of the video signal Sv, for example, 5.0 to 8.5 MHz is multiplexed with the 4.2 MHz video signal Sv. Therefore, the signal S _BS is also FM
It is a signal.

Here, the audio mode of the satellite signal S _BS is monaural, multiplex, discrete, there is a respective matrix. The FM audio signal S _{AFM in} the monaural mode is obtained by FM-modulating a single carrier in the 5.0 to 8.5 MHz band with the monaural audio signal S _A , and its frequency deviation is, for example, 75 KHz. The FM audio signal S _{AFM in} the multiplex mode is the left audio signal L and the right audio signal R.
The sum signal (L + R) and the difference signal (L-R)
A single carrier in the 5.0 to 8.5 MHz band is FM-modulated by the composite signal with the FM-modulated signal, and its frequency deviation is, for example, 10
It is set to 0 KHz.

In addition, FM audio signal S _AFM in discrete mode
Is 5.0-8.5MHz for left audio signal L and right audio signal R respectively
The first and second carriers of the band are FM-modulated, and the frequency deviation thereof is, for example, 75 KHz. In this case, the interval between the first and second carriers is often 0.18 MHz, for example. Further, the FM audio signal S _AFM in the matrix mode is a sum signal (L + R) and a difference signal (LR), respectively.
The first and second carriers of 5.0 to 8.5 MHz are FM-modulated, and the frequency shift thereof is, for example, 100 KHz. In this case, the interval between the first and second carriers is often 1.00 MHz, for example.

The position of the carrier of the FM audio signal S _{AFM in} each mode described above is not fixed in a uniform manner, and is arbitrary in the 5.0 to 8.5 MHz band, or the highest frequency is the monaural mode. 6.80 MHz in the multiplex mode, 5.58 MHz and 5.76 MHz in the discrete mode, and 5.80 MHz and 6.80 MHz in the matrix mode.

The number of channels in the ku band and the c band is 24, for example.
As a channel, an example of the channel configuration of the c band is shown in FIG. As shown in FIG. 3, the required bandwidth per channel is 27 MHz, and the frequency interval between the channels is about 20 MHz. In addition, the polarization plane of the broadcast signal S _BS of each channel is made different in the adjacent channels, and the horizontal polarization signal is used in the odd-numbered channels of (1,3, ... 23) and (2,4, ... 2
In the even channels 4) vertical polarization signal is used, are adapted to broadcast signals S _BS of adjacent channels do not interfere with each other.

Further, in FIG. 1, the signal S from the S / U converter 12 is
_BS is supplied to the signal processing circuit 14 of the tuner 1 via the terminal 13. In this signal processing circuit 14, the signal S _BS of 950 to 1450 MHz is converted into an intermediate frequency signal of 402.78 MHz, for example, and FM modulated, and the video signal Sv and FM audio signal S _AFM as shown in FIG. And a combined signal S ₀ is output from the signal processing circuit 14.

In this case, the reception channel is selected by changing the frequency of the local signal S _L supplied from the PLL circuit 15 for frequency conversion. The control of the PLL circuit 15 is performed by a microcomputer (hereinafter referred to as “microcomputer”) 17 based on a user's operation on the operation panel 16, and the frequency division ratio of the frequency divider of the PLL circuit 15 depends on the channel. It is performed by being controlled. Further, the signal S _AFT indicating the change of the intermediate frequency is supplied from the processing circuit 14 to the microcomputer 17 so that the intermediate frequency signal is correctly 402.78 MHz.
The action is taken.

b. Explanation of receiving channel selection Here, the receiving channel is randomly selected with the ten keys "1" to "0" on the operation panel 16, and is sequentially selected with the up key 161 and the down key 162. It

First, the random channel selection will be described. When the user presses a number corresponding to a desired channel with ten keys “1” to “0” on the operation panel 16 and finally presses the enter key “ENTER”, the microcomputer 17 causes the frequency divider of the PLL circuit 15 to divide the frequency. The ratio is changed so that the local signal S from the PLL circuit 15
The frequency of _L is changed and the desired channel is selected.

Incidentally, as described above, the polarization plane of the broadcast signal S _BS corresponding to each channel is determined in the horizontal or vertical. Therefore, when changing the reception channel, it is necessary to match the reception polarization plane with the reception channel. A key 163 on the operation panel 16 is for switching the reception polarization plane. That is, from the microcomputer 17 through the amplifier 18, the terminal 19
The state of the switching signal S _PO which is output to the S / U converter 12 and changes the reception polarization plane by changing the reception polarization plane is sequentially changed by the operation of the key 163, whereby the reception polarization plane is switched.

Next, the sequential channel selection will be described. Operation panel by user
16 Press the Up key 161 or Down key 162 above,
Dividing ratio of the frequency divider of the PLL circuit 15 is changed sequentially by the microcomputer 17, therefore, the local signal S _L from the PLL circuit 15
The frequencies are sequentially changed, and the receiving channels are sequentially switched and selected. In this case, when the up key 161 is pressed, 1 → 3 → ・ ・ ・ → 23 → 2 → 4 → ・ ・ ・ → 24 →
When the receiving channel is selected like 1 → 3 ... and the down key 162 is pressed, 23 → 21 → ... →
Channels are selected as 1 → 24 → 22 → ・ ・ ・ → 2 → 23 → 21 → .... That is, the odd channel and the even channel are selected alternately. Also, as mentioned above,
For example, since the polarization planes of the odd channels are horizontal and the polarization planes of the even channels are vertical, the reception polarization planes are switched when moving from the even channels to the odd channels and from the odd channels to the even channels. That is, at this time, the state of the switching signal S _FO from the microcomputer 17 is changed and the reception polarization plane is switched.

The flow chart of FIG. 4 shows the operation at the time of this sequential channel selection. That is, when the up key 161 is pressed, 2 is added to the number of channels CH. Next, it is judged whether the number of channels CH is 25 or more. When it is not 25 or more, the channel of the number of channels CH is selected. On the other hand, when it is 25 or more, it is determined whether it is an even number or an odd number. When the number is odd, the number of channels CH is set to 2, and when the number is even, the number of channels CH is set to 1.
Then, the reception polarization plane is inverted, and the channels with the number of channels CH are selected. While the up key 161 is being pressed, the above operation is repeated, and the reception channel when the pressing is stopped is finally selected.

When the down key 162 is pressed, the number of channels CH
Is subtracted by 2. Next, it is determined whether the number of channels CH is 0 or less. When it is not less than 0, the channel of the number of channels CH is selected. On the other hand, when it is 0 or less, it is determined whether it is an even number or an odd number. When the number is odd, the number of channels CH is set to 24, and when the number is even, the number of channels CH is set to 23. Then, the reception polarization plane is inverted, and the channels with the number of channels CH are selected. While the down key 162 is being pressed, the above operation is repeated, and the receiving channel when the pressing is stopped is finally selected.

At the time of this channel selection, the display unit 201 of the display panel 20 displays the number of selected reception channels. First
In the example of the figure, it is shown that the channel is in the channel 6 selection state. Further, when the reception polarization plane is switched to horizontal or vertical, the display unit 202 or 203 of the display panel 20 is lit and displayed, respectively. Here, the display unit 204 of the display panel 20 is lit and displayed when the broadcast is received. Also, the display unit 205
Is lit when receiving the ku band or the c band, for example, when receiving the c band.

Further, the combined output S ₀ output from the signal processing circuit 14 (second
Is supplied to the de-emphasis circuit 21, and the signal pre-emphasized at the transmission side is restored. The output of the de-emphasis circuit 21 is supplied to the low-pass filter 22, the video signal Sv is taken out, the video signal Sv is amplified by the amplifier 23 and then supplied to the energy spread signal removal circuit 24. In this removal circuit 24, the video signal on the transmission side
The triangular wave energy diffusion signal superimposed on Sv is removed, and the video signal Sv from this removal circuit 24 is output to the output terminal 26 via the muting circuit 25. In the signal processing circuit 14, the muting circuit 25 uses the intermediate frequency 402.
It is controlled by a control signal S _MV formed from the presence or absence of a 78 MHz carrier wave, and is put into a muting state when there is no intermediate frequency 402.78 MHz carrier wave.

c. Description of Audio System Further, the combined output S ₀ output from the signal processing circuit 14 is supplied to the bandpass filter 30, and the FM audio signal S _AFM whose carrier is located in the 5.0 to 8.5 MHz band is extracted. Then, this FM audio signal S _AFM is supplied to PLL circuits 31 and 32 which include a mixer and constitute a frequency converter. These PLL circuits 31 and 32 are for converting the carrier wave of the FM audio signal S _AFM to 10.7 MHz. In this case, since the single carrier in the 5.0 to 8.5 MHz band is used when the audio mode is the monaural mode or the multiplex mode as described above, the converted output can be obtained from the PLL circuit 31, for example. On the other hand, in the discrete mode or the matrix mode, since the first and second carriers in the 5.0 to 8.5 MHz band are used, the conversion outputs can be obtained from both the PLL circuits 31 and 32.

Here, as described above, the position of the carrier of the FM audio signal S _AFM in each mode is not uniformly determined, and is 5.0 to 8.5.
It is optional in the MHz band. Therefore, in order to receive the desired FM audio signal S _AFM , that is, in order to convert the carrier wave of the FM audio signal S _AFM to the intermediate frequency of 10.7 MHz, the microcomputer is operated based on the key operation on the operation panel 16 by the user. PLL from 17
The frequency division ratio control signals SN ₁ and SN ₂ are supplied to the circuits 31 and 32, respectively, and the frequency division ratios of the frequency dividers of the PLL circuits 31 and 32 are controlled to perform so-called tuning.

A key 164 on the operation panel 16 is a key for selecting a voice mode, and by sequentially pressing the key 164, the voice mode is selected as monaural → multiplex → discrete → matrix → monaural →. In this case, when switching to the monaural mode and the multiplex mode, the tuning frequency f ₁ in the PLL circuit 31 is, for example,
Automatically tuned to 6.80MHz. Further, when switching to the discrete mode, the tuning frequencies f ₁ and f ₂ of the PLL circuits 31 and 32 are, for example, 5.58 MHz and 5.7, respectively.
Automatically tuned to 6MHz. Furthermore,
When switching to the matrix mode, the tuning frequencies f ₁ and f ₂ of the PLL circuits 31 and 32 are automatically tuned so as to be, for example, 5.80 MHz and 6.80 MHz, respectively.

The tuning frequency is kept constant at the time of switching between the modes, but when the position of the carrier of the FM audio signal S _AFM is not at this tuning frequency, the user is made to tune by operating the keys on the operation panel 16. Here, the tuning is performed by pressing the voice tuning key 165 on the operation panel 16 and then using the ten keys "1" to "0" or the up key 161 and the down key 162.

In Fig. 1, the carrier wave obtained from the PLL circuit 31 is 10.7M.
The audio signal S _{A1 of} Hz passes through the narrow band pass filter 33 and the wide band band pass filter 34, and the changeover switch 35 respectively.
Are supplied to the fixed terminals on the A side and the B side. The audio signal S _A2 having a carrier of 10.7 MHz obtained from the PLL circuit 32 is supplied to the fixed terminals on the A side and the B side of the changeover switch 38 via the narrow band band pass filter 36 and the wide band band pass filter 37, respectively. . When the audio mode is monaural mode and discrete mode, the frequency deviation is, for example, 75 KHz.
Since it is relatively narrow, the changeover switches 35 and 38 are changed over to the A side, and from this changeover switches 35 and 38, the audio signals S _A1 and S A which have passed through the narrow band band pass filters 33 and 36.
_A2 is obtained. On the other hand, when the audio mode is the multiplex mode or the matrix mode, the frequency deviation is relatively wide, for example, 100 KHz, so that the audio signals S _A1 and S _A2 passed through the wide band pass filters 34 and 37 from the changeover switches 35 and 38. Is obtained.

The changeover switches 35 and 38 are changed over as follows. That is, the microcomputer 17 generates a 2-bit signal [A, B] corresponding to the selection of the voice mode. That is, [1,1] is generated in the monaural mode, [0,0] is generated in the multiplex mode, [1,0] is generated in the discrete mode, and [0,1] is generated in the matrix mode.

The signal A is "1" in the monaural mode and the discrete mode, and is "0" in the multiplex mode and the matrix mode.
Is supplied as a switching signal. When the signal A is "1", it is switched to the A side, and when it is "0", it is switched to the B side.

The audio signals S _A1 and S _A2 extracted from the change-over switches 35 and 38 are supplied to the FM demodulators 39 and 40, respectively. And
Demodulated outputs from these FM demodulators 39 and 40 are voice processing circuits.
Supplied to 41.

The audio processing circuit 41 performs processing according to each audio mode. That is, the 2-bit signal [A, B] from the microcomputer 17 is supplied to the decoder 42, is converted into the 4-bit signal [a, b, c, d] by the decoder 42, and is sent to the audio processing circuit 41 as a control signal. Supplied as. For example, [1,1] in monaural mode is [1,0,0,0], [0,0] in multiplex mode is [0,1,0,0], and [1,0] in the case is converted to [0,0,1,0], and [0,1] in the matrix mode is converted to [0,0,0,1]. As a result, the audio processing circuit 41 is controlled, and processing according to each audio mode is performed.

In the monaural mode, monaural audio signals are extracted from the first and second outputs of the processing circuit 41 and output to the output terminals 47 and 48 via the amplifiers 43 and 44 and the muting circuits 45 and 46, respectively. . In the case of the multiplex mode, the discrete mode, and the matrix mode, the left audio signal L and the right audio signal R are extracted from the first and second outputs of the processing circuit 41, respectively, and the amplifiers 43 and 44 and the muting circuit 45, respectively. Output terminal 47 via
And 48.

Further, the FM demodulation circuits 39 and 40 output signals S _M1 and S _M2 , respectively, which have a low level “0” when there are audio signals S _A1 and S _A2, and a high level “1” when there are none, and the AND circuits 49 respectively. Is supplied to. The muting circuits 45 and 46 are operated when the output of the AND circuit 49 is at a high level "1", that is, when there is no audio signal S _A1 or S _A2 .

Further, the signals S _M1 and S _M2 from the FM demodulation circuits 39 and 40 are supplied to the microcomputer 17 and used for the sweep speed control at the time of tuning the audio signal by the up key 161 or the down key 162 as described above.

d. Description of fine tuning function The key 166 of the operation panel 16 is a fine tuning key. That is, the broadcast signal from the broadcasting satellite (SHF
Wave) and ground communication signals (SHF waves) to prevent beat interference, and slightly shifts the center frequency of tuning for selecting the receiving channel in the signal processing circuit 14.

When the fine tuning key 166 is pressed, the display section 201 of the display panel 20 displays a display as shown in FIG. 5A. In FIG. 5A, “00.0” indicates that the center frequency of tuning is not displaced. Next, when the up key 161 or the down key 162 is pressed, the center frequency of tuning is shifted in steps of 0.2 MHz, for example. In other words, in FIG. 6, if f ₁ is the ground wave interference frequency and f _J is the center frequency of the original tuning, for example, f _F will be Δf in 0.2 MHz steps.
The center frequency is shifted only by
The shifted frequencies are displayed as shown in FIG. This frequency shift amount Δf is set to such a degree that the influence of terrestrial waves becomes inconspicuous on the screen, for example, ± 10 MHz, and at the same time, the video output of the adjacent channel, which is prohibited from receiving when the polarization plane is switched, does not occur. , About ± 5 MHz, for example.

At this time, the AFT operation is prohibited, and the shifted frequency is prevented from returning to the original. When the reception channel is switched, the prohibition of this AFT operation is released. The AFT operation is started at power-on.

The flow chart of FIG. 7 shows the operation relating to the above fine tuning. That is, at power-on
AFT operation starts. Then, when the fine tuning key 166 is pressed, the center frequency of tuning can be shifted.

When the up key 161 is pressed, whether or not the adjacent channel in the direction of increasing the frequency is prohibited from reception is determined based on the identification signal stored in the non-volatile memory 50 when setting the reception prohibited channel described later. To be done. When the adjacent channel is not prohibited from receiving, it is determined whether the deviation amount Δf is +10 MHz. +1
If it is not ₀ MHz, the tuning center frequency f ₀ is f _0.
When the frequency is ± 0.2 MHz and +10 MHz, the center frequency f ₀ of tuning is tuned as it is.
When the adjacent channel is prohibited from receiving, it is determined whether the shift amount Δf is +5 MHz. +
If it is not 5 MHz, the tuning center frequency f ₀ is f _0.
It is set to +0.2 MHz, and in the case of +5 MHz, the tuning center frequency f ₀ is tuned as it is.

After tuning is performed at f ₀ , AFT operation is prohibited and the key sense is restored. The above operation is repeated while the up key 161 is being pressed.

That is, the maximum value that the deviation amount Δf can take is switched depending on whether or not the adjacent channel in the direction of increasing the frequency is prohibited from receiving, and when the adjacent channel is prohibited from receiving, the deviation occurs. The maximum value of quantity Δf is +
It is set to 5 MHz, and the center frequency f ₀ is forcibly shifted in 0.2 MHz steps within the narrowed range.

On the other hand, when the down key 162 is pressed, whether or not the adjacent channel in the direction of lowering the frequency is prohibited from reception is based on the identification signal stored in the nonvolatile memory 50 when setting the reception prohibited channel described later. Will be judged. When adjacent channels are prohibited from receiving, it is determined whether the deviation amount Δf is −10 MHz. When it is not −10 MHz, the tuning center frequency f ₀ is set to f ₀ −0.2 MHz, and when it is −10 MHz,
The tuning center frequency f ₀ is tuned as it is. When the adjacent channel is prohibited from receiving, it is determined whether the deviation amount Δf is −5 MHz. Center frequency of tuning if not -5 MHz
When f ₀ is set to f ₀ −0.2 MHz and −5 MHz, the tuning center frequency f ₀ is tuned as it is.

After tuning is performed at f ₀ , AFT operation is prohibited and the key sense state is restored. The above operation is repeated while the down key 162 is being pressed.

In other words, the minimum value that the deviation amount Δf can take is switched depending on whether or not the adjacent channel in the direction of lowering the frequency is prohibited. If the adjacent channel is prohibited from receiving, the deviation is The minimum value of the quantity Δf is −
It is set to 5 MHz, and the center frequency f ₀ is forcibly shifted in 0.2 MHz steps within the narrowed range.

For example, assuming that the total number of channels is 24, reception prohibited channels are set for each channel as shown in the table below.

If the channel whose identification signal is "1" in the table is a reception prohibited channel, (2,6,10,1
4,16,22) The deviation width is narrowed in the direction of lowering the frequency during fine tuning. Also, (3,8,
12,14,20) The deviation width is narrowed in the direction of increasing the frequency of the fine tuning channel. In addition, (7,11,1
For channels (2,17,18,19,23,24), the shift width cannot be changed.

Further, when there is a key-in by the ten keys "1" to "0", the prohibition of the AFT operation is released, and the tuning-in reception channel of the keyed-in numeral is selected.

e. Description of reception prohibition function The key 167 on the operation panel 16 is a key for setting and canceling reception prohibition (parental lock). When the key 167 of the operation panel 16 is pressed while a predetermined channel is selected, a display indicating that reception prohibition can be set is displayed on the display unit 201.

Next, when the three-digit index signal ID is input with the ten keys “1” to “0” and the enter key “ENTER” is pressed, the input index signal ID and the non-volatile memory 50
The index signal ID ₀ corresponding to a predetermined channel stored in advance is compared. When the index signals match, a display indicating that the predetermined channel currently selected is set as the reception inhibition target is displayed on the display unit 201, and the nonvolatile memory 50 corresponds to the predetermined channel. Identification signal in the form of, for example, "1"
Is stored and the reception is prohibited.

In this case, since the reception is prohibited, the frequency division ratio of the PLL circuit 15 is changed and the frequency of the local signal S _L is changed.
The center frequency of tuning is outside the band of 950 to 1450 MHz band,
For example, it is set to 1480MHz. Therefore, when the reception prohibited state is set, the signal processing circuit 14 detects
There is no 78 MHz carrier wave, and the muting circuit 25 operates to enter the video muting state. At this time, since the signals S _M1 and S _M2 from the FM demodulation circuits 39 and 40 are both at the high level “1”, the muting circuits 45 and 46 operate to enter the voice muting state.

On the other hand, when the index signal ID does not match ID ₀ , the display is returned to the original display, and the selected predetermined channel is not set to the reception prohibited state.

Also, when a predetermined channel is selected and this channel is in the reception prohibited state, the key on the operation panel 16
When 167 is pressed, a display indicating that reception prohibition can be released is displayed on the display unit 201. Next, when a three-digit index signal ID is input with the ten keys “1” to “0” and the enter key “ENTER” is pressed, the input index signal ID and a predetermined value stored in the non-volatile memory 50 in advance. Index signal ID corresponding to the channel
₀ is compared. When the index signals match, a display indicating that the predetermined channel which is in the reception prohibited state at that time is excluded from the reception prohibited object is displayed, and the predetermined channel is displayed in the nonvolatile memory 50. The identification signal, for example, “0” is stored in a form corresponding to, and the reception prohibited state is released.

In this case, when the reception prohibited state is released, the center frequency of tuning is returned to the correct position, so that the operations of the muting circuits 25, 45 and 46 are also stopped and the muting state is released.

On the other hand, if the index signal ID does not match ID ₀ ,
The display is returned to the original display, and the predetermined channel for which reception is prohibited is not released from the reception prohibited state.

Further, when changing the index signal ID ₀ corresponding to a predetermined channel stored in the non-volatile memory 50, the following is performed. That is, when the key 167 of the operation panel 16 is pressed while a predetermined channel is selected, a display indicating that the index signal ID ₀ can be changed is displayed on the display unit 201. Next, the numeric keypad "1" to "0"
The 3-digit index signal ID1 is input with, and the 3-digit index signal ID2 is also input.
When "ER" is pressed, the index signal ID previously input
1 is compared with the index signal ID ₀ corresponding to a predetermined channel stored in advance in the non-volatile memory 50. When the index signal is matched, the index signal ID2 input later is stored in the nonvolatile memory 50 as the index signal ID _0.

On the other hand, when the index signal ID1 and ID ₀ is discrepancy can not change the index signal ID ₀ stored in the nonvolatile memory 50, is as it is, the display unit 201 is, for example, "≡ ≡≡ ”is displayed.

The factory-shipped non-volatile memory 50 stores the index signal ID ₀ common to each set corresponding to each channel.

In addition, the index signal ID ₀ stored in the memory 50
When forgetting, a factory code, that is, a master key-like index signal, for example, "999" is prepared, and in the worst case, this is used.

The flowchart of FIG. 8 shows the above operation. That is, in the channel selection state of the predetermined reception channel,
When the key 167 of the operation panel 16 is pressed, for example, “P” is displayed on the display unit 201, and the reception inhibition is set, the inhibition is released, or the index signal ID ₀ is registered. Next, when the index signal is input with the ten keys "1" to "0" and the enter key "ENTER" is pressed, it is determined whether or not there are three digits. In the case of three digits, one index signal ID has been input with the ten keys “1” to “0”, so this input index signal ID is next stored in the nonvolatile memory 50. It is determined whether or not it matches with ID ₀ . If they do not match, the display on the display unit 201 is restored. The key sense is set. If they match, it is determined whether or not the reception is prohibited. If it is not in the reception prohibited state, it is determined that the operation is to set the reception prohibited state, and the reception prohibited state is set. Then, the center frequency of tuning is out of band, and "PL" is displayed on the display unit 201, and the key sense is set. If the reception is prohibited, it is determined that the operation is for canceling the reception, and the reception prohibited state is canceled. Then, the center frequency of tuning is returned to the original position so that the predetermined channel can be received, "PL" on the display unit 201 is erased, and the key sense is restored.

If it is not 3 digits, then it is judged whether it is 6 digits or not. If it is not 6 digits, it is returned to the original display and the key sense is set. It In the case of 6 digits, use the numeric keypad "1" to "0" to display the index signal ID
Since 1 and ID2 have been continuously input, it is next determined whether or not the input index signal ID1 matches the index signal ID ₀ previously stored in the nonvolatile memory 50. If they do not match, it is determined whether the code is a factory code. If it is not a factory code, for example, "≡≡≡" is displayed,
The key sense is set. Meanwhile, the index signal ID1
And ID ₀ match, or index signal ID 1
There when a factory code, the input index signal ID2 is stored in the memory 50 as the index signal ID _0. The index signal ID2 is displayed on the display unit 2.
It is displayed in 01 and the key sense is set.

The key 168 of the operation panel 16 is a key for making the signals output to the output terminals 26, 47, 48 into external input signals.
For simplicity of the drawing, FIG. 1 does not show the external input terminal, the change-over switch and the like. Further, for example, when the display is switched to the external input side, the display unit 211 of the display panel 20 is lit and displayed.

In the embodiment of the present invention, it has been described that the polarization planes of the odd channels are horizontal and the polarization planes of the even channels are vertical. The same applies to cases. In addition, the reception prohibition state is set to be out of the band (950 to 1450 MHz band), but it may be set to a value that cannot be received between stations even in the band. Further, the case where the deviation amount is set to ± 5 MHz when the reception of the adjacent channel is prohibited has been described, but other deviation amounts may be set so that the broadcast signal of the adjacent channel is not output.

〔The invention's effect〕

According to the present invention, when the predetermined channel is set as the object of the reception prohibition by using the reception prohibition function, the identification signal indicating the reception prohibition channel is stored in the memory in a form corresponding to the predetermined channel. When the fine tuning function is used at the time of tuning, it is determined whether or not the adjacent channel of the receiving channel is the target of reception inhibition based on the identification signal stored in the memory,
When adjacent channels are prohibited from receiving, the width of frequency deviation is narrowed.

Therefore, according to the present invention, the setting of reception inhibition is not easily released, and the frequency deviation width is narrowed when the adjacent channel is inhibited during fine tuning. Since the broadcast signal of the prohibited channel is not output because of being narrowed, the broadcast number of the prohibited channel can be surely not seen, and the reception prohibiting function can be sufficiently exerted.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, FIGS. 2 and 3 are schematic diagrams used for explaining one embodiment of the present invention, and FIG. 4 is a sequential channel selection in one embodiment of the present invention. FIG. 5 and FIG. 6 are schematic diagrams used for explaining the fine tuning in one embodiment of the present invention, and FIG. 7 is an explanation of the fine tuning function in one embodiment of the present invention. Flowchart used for
FIG. 8 is a flow chart used for explaining the reception inhibiting function in the embodiment of the present invention. Description of main symbols in the drawings 1: Tuner, 16: Operation panel, 17: Microcomputer, 50: Non-volatile memory.

Claims (1)

[Claims] 1. A receiving device adapted to prohibit the output of a broadcast signal of a predetermined channel, a fine adjustment means for shifting a tuning frequency, and a memory for storing an identification signal for identifying the predetermined channel. By referring to the identification signal stored in the memory at the time of tuning, it is determined whether or not the adjacent channel of the receiving channel is set to output inhibition, and the adjacent channel of the receiving channel is set to output inhibition. In this case, means for narrowing the width of the frequency deviation of the fine adjustment means is provided.