JPH07240669A - Automatic channel preset system - Google Patents

Abstract

PURPOSE:To preset channels to all the selection station keies even in a weak electric field by selecting the channels equal to the number of selection station keies or below in order of radio wave intensities and making the selected channel correspond to the selection key. CONSTITUTION:Channels are selected in order or levels of synchronizing signals by a microcomputer 10 and a synchronizing signal detection circuit 8. Therefore, if AGC voltage is properly set by an AGCATT signal, the number of a channel of 'presence of signal' can be set to an arbitrary number N. A position selection station key 9 is connected with the PLL synthesizer of a tuner 2 via the microcomputer 10 and each selection key is made to correspond to N channels by 1 to 1 basis. When an arbitrary key of the selection keys is depressed, the corresponding channel is preset to be selected. As a result, the channel of an unnecessary weak electric field is removed, the only number of large radio wave intensity channel corresponding to the number of selection station key is selected, and a preset can be performed automatically in short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position-selection television, which automatically sets channels such as VHF, UHF and satellite broadcasting in correspondence with position selection keys. Regarding

[0002]

2. Description of the Related Art Recently, with the advent of multi-channel television in the world and domestically, the range of channel selection has been widened for viewers. However, on the other hand, if you try to select all channels for tuning, the tuning key will be large and not easy to handle, the price will be high, and it will take a long time to select the tuning key in the weak electric field area. Even if it is provided, various problems such as many useless parts actually occur.

Therefore, recently, a channel auto preset system of a position tuning key system has been developed. This is to limit the number of tuning keys to an appropriate number, select N channels from all channels, and automatically preset the selected channel to the tuning key.

As a first example of the conventional channel auto-preset system, a method of performing channel search from a lower frequency side to a higher frequency side and sequentially assigning a channel selection key to channels from which radio waves have been received has been put into practical use. There is.

As a second example of the method, a method has been put into practical use in which the number of candidate channels is reduced by narrowing the AGC of the television and then the preset is performed.

[0006]

However, in the first method, channels with low frequencies are preset even if the radio waves are weak, but channels with high frequencies have a limited number of tuning keys. There was a problem that it was not preset even if the radio wave was strong.

Further, the second method has a problem that in a region where the radio wave is weak, the channel desired by the viewer is not preset in the tuning key even if the radio wave intensity is weak.

Therefore, there is a problem to be solved in a channel auto-preset system that does not preset unnecessary weak electric field channels, but on the other hand, can surely preset the channel that the viewer wants to see in the weak electric field area. Have

[0009]

In order to solve the above-mentioned problems, the channel auto-preset system according to the present invention has the same or the same number as that of a plurality of tuning keys in the order of strongest radio wave strength from a plurality of channels. This means that the following number of channels are selected, and each selected channel is specified as an arbitrary tuning key for the plurality of tuning keys.

The selection of the channel is performed by controlling the AGC circuit to change the gain of the tuner stepwise; the selection of the channel is performed when the number of channels corresponding to the number of the tuning keys is selected. Changing the selection reference value of the channel and searching for a channel that has not been selected yet; the selection of the channel detects all the channels that exceed the set reference value, and the detected channel is the plurality of selection keys. If the number is larger than the above, the reference value is sequentially changed until the number of detected channels is equal to or smaller than the number of the selection keys;
The change of the reference value is performed in the direction of larger values; the channel selection is a channel auto-preset system in which the search is performed in ascending order of frequency.

[0011]

The channel auto-preset system configured as described above has the following operation.

(1) From a plurality of channels, select the same number of channels as the number of channel selection keys or the number of channel selection keys in descending order of radio field intensity, and select the selected channels from the channel selection keys. By adopting the above-mentioned method, unnecessary weak electric field channels can be removed, and channels with the maximum number of tuning keys can be preset even in a weak electric field region.

(2) Channel selection is performed by controlling the AGC circuit to change the gain of the tuner stepwise, thereby removing unnecessary weak electric field channels by narrowing down the AGC, and weak electric field. In the area, it becomes possible to select a channel in a state where a weak electric field channel is obtained without narrowing the AGC.

(3) When a predetermined reference value is set and channels are selected in ascending order of frequency by the number of tuning keys,
By changing the reference value to a large value and selecting the selected channel and the remaining channels repeatedly until there are no more channels, the time of the selected channel is shortened as the number of repetitions increases. Will be able to.

(4) When selecting channels, all channels exceeding a predetermined reference value are detected in order of increasing frequency, and if there are more detected channels than the selection key, the reference value is changed to a smaller value. The search time can be shortened by repeating the process until the number of detected channels is equal to or less than the number of selection keys.

[0016]

Embodiments of the channel auto preset system according to the present invention will be described below.

As shown in FIG. 1, a channel auto-preset system 1A according to the present invention includes an antenna 1, a tuner 2, a VIF circuit 3, a detection circuit 4, a video circuit 5, a CRT 6, and an AGC circuit 7. And a synchronization signal detection circuit 8, a position tuning key 9, a microcomputer 10, a memory 11, and an auto preset switch 12.

Among these, the antenna 1, the tuner 2 and the V
IF circuit 3, detection circuit 4, video circuit 5, CRT
6 and the AGC circuit 7 are common television receiver 1
B is formed, position tuning key 9 and microcomputer 10
The memory 11 and the auto preset switch 12 form an auto preset unit 1C. The connection and each function of the auto preset system 1A including the television receiver 1B and the auto preset unit 1C are as follows.

The tuner 2 is composed of a PLL synthesizer connected to the microcomputer 10. The tuner 2 tunes to the frequency of the channel set by the channel setting signal from the microcomputer 10 in the received radio wave input from the antenna 1, and outputs the received signal of this channel to the VIF circuit 3. The frequencies that can be received by the tuner 2 include VHF, UHF, satellite broadcasting and the like.

The output voltage of the tuner 2 is proportional to the radio wave intensity of the selected channel. In other words, the output voltage of the tuner 2 is large in the channel with high radio field intensity,
The output voltage is low on the channel with low radio field intensity.

The VIF circuit 3 converts the input signal from the tuner 2 into an intermediate frequency signal, outputs the intermediate frequency signal to the detection circuit 4, and outputs the AGC voltage to the AGC circuit 7.

The detection circuit 4 extracts a video signal and an audio signal from the intermediate frequency signal from the VIF circuit 3, outputs the video signal to the video circuit 5, and outputs the audio signal to an audio circuit (not shown).

The video circuit 5 separates the video signal from the detection circuit 4 into three color signals of R, G and B, and outputs them to the CRT 6. The CRT 6 displays a television image based on the R, G, B signals from the video circuit 5.

The sensitivity of the tuner 2 is the AGC circuit 7
It is automatically adjusted by the AGC voltage supplied from. An example of the relationship between this sensitivity and the AGC voltage is shown in FIG.

Further, the AGC circuit 7 is connected to the microcomputer 10, and the AGC attenuation signal AG from the microcomputer 10 is sent.
I am receiving CATT. As a result, the microcomputer 10
Can change the value of the AGC voltage to the tuner 2 stepwise by changing the AGCATT signal to 0, 1, 2, ...

The sync signal detection circuit 8 extracts a sync signal (SYNC) from the video signal output from the detection circuit 4, compares the level of this sync signal with a certain reference value, and when the level is greater than the reference value. For example, a channel discarding signal which is "1" and otherwise "0" is output to the microcomputer 10.

The level of the synchronizing signal is, of course, the AGC circuit 7
It changes by changing the AGC voltage of. Since this AGC voltage changes according to the AGCATT signal from the microcomputer 10, the level of the synchronizing signal is controlled by the microcomputer 10.

FIG. 3 shows the relationship between the AGCATT signal and the level of the sync signal of each channel. For example, AGCAT
When the T signal is 0, channel numbers 1, 2, 3, 4,
Assuming that the levels of the synchronization signals of 5, 6, 7, and 8 are as shown in FIG. 3A, if the AGCATT signal is set to "1" to raise the AGC voltage and the gain of the tuner 2 is narrowed, FIG.
As shown in (b), the levels of the synchronization signals of the channels 1 to 8 are uniformly reduced.

Next, when the AGCATT signal is set to "2" and the gain of the tuner 2 is further narrowed down, the level of the synchronizing signal of each channel is further reduced, as shown in FIG.

Now, for example, a reference level L, which is the reference value shown in FIG. 3, is set in the sync signal detection circuit 8, and only the channels whose sync signal level is higher than this reference level L are judged as "signal present". , And the others are configured to be determined as “no signal”.

Then, in the case of FIG. 3A, it is determined that all the channels 1 to 8 are “signal present”, and in the case of FIG. 3B, the channels 2, 3, 5, and 8 are “signal present”. Yes ”
, Channels 1, 4, 6, 7 are determined to be “no signal”, and in the case of FIG. 3C, channel 2,
Only Nos. 5 and 8 are judged to be "signal present".

In other words, by configuring the microcomputer 1 and the sync signal detection circuit 8 as described above, the channels are selected in the order of the highest sync signal level. Therefore, if the AGC voltage is appropriately set by the AGCATT signal, the number of "signaled" channels can be set to an arbitrary number N.

This is nothing but selecting N channels with high radio field intensity by uniformly raising and lowering the level of the synchronization signal of the channels by changing the AGC voltage.

The position tuning key 9 has N tuning keys and is connected to the PLL synthesizer of the tuner 2 via the microcomputer 1. Each tuning key is the selected N
Each channel is associated with one-to-one correspondence, and when any one of them is pressed, the corresponding channel is "preset".

The microcomputer 10 sends a channel setting signal to the tuner 2 for channel selection, and at the same time, the AGC circuit 7 receives an A signal.
The GCATT signal is sent to set the AGC voltage, and the sync signal detection circuit 8 inputs a binary signal representing the sync signal of the selected channel as “with signal” or “without signal”.

Further, the microcomputer 10 has a built-in auto preset program, which will be described later, and is adapted to start execution by turning on the auto preset switch 12.

The memory 11 has memory locations A (1) to A (N) having the same number of memory locations as the number N of the position selection keys 9. The N memory locations A (1) to A (N) will be referred to as preset areas. In this preset area, the channel number finally preset in the tuning key is stored.

The operation of the first embodiment of the channel auto preset system according to the present invention will be described below with reference to the flow chart shown in FIG.

In the first embodiment, a channel search is performed from a lower frequency to a higher frequency (or vice versa), a channel whose radio field intensity exceeds a certain reference value is detected, and stored in a preset area. When the number of selected channels exceeds the number of tuning keys, the search is stopped, the reference value of the radio field intensity is lowered next, and new channels are newly added to the channels stored in the preset area and the channels left unsearched last time. Performs detection and storage with the reference value, repeats the above operation loop until the number of channels stored in the preset area becomes equal to or smaller than the number of positions, and there are no channels left to search, and finally the preset area. It is configured to preset the channel stored in to the tuning key.

This operation is as follows. (1) When the preset program starts, first, the preset areas A (1) to A (N) are cleared (step ST1). However, this is not absolutely necessary.

(2) The AGCATT signal is set to 0 (step ST2). Note that the AGCATT signal lowers the output level of the tuner 2 as the number increases.

(3) CH number count index i
And the count index j of the number of channels stored in the preset area is set to 0 (step ST
3).

(4) In step ST4, the indexes i and p are each incremented by 1. It should be noted that the index p indicates the CH number at the beginning of the channel left unsearched when there is still a channel that has not been searched when the preset area becomes full in each operation loop thereafter.

(5) In step ST5, i is compared with N. If i is larger than N, the process proceeds to step ST7 to search for the channel left over from the previous search. If not, the process jumps to step ST6. Search for channels in the preset area.

(6) In step ST6, the frequency of CH number A (i) is set in tuner 2. Also,
In step ST7, the frequency of CH number p is set in tuner 2. This is performed by sending a channel setting signal from the microcomputer 10 to the tuner 2 for channel selection, and as a result, the received signal of the selected channel is input to the detection circuit 4.

(7) Then, the sync signal detection circuit 8 generates a channel discard signal based on the sync signal from the detection circuit 4 and sends it to the microcomputer 10, as described above.

(8) In step ST8, the microcomputer 10 returns to step ST4 if the channel cut-off signal from the sync signal detection circuit 8 is "no signal", moves to the next channel, and if "signal is present", step ST9
Go to.

(9) In step ST9, the number j of channels stored in the preset area is incremented by 1, and the process proceeds to step ST10. (10) In step ST10, the preset area A
The contents of (j) are replaced with i, and the process proceeds to step ST11.

(11) In step ST11, steps ST4 to ST10 are repeated until j becomes equal to N. (12) As a result, until the preset area becomes full,
Channels with high radio field intensity are sequentially selected from channels with low frequencies, and preset areas A (1) to A
(N) is stored.

(13) Next, at step ST12, when the preset area is full, i is still M.
If it is not smaller, that is, if there are still unsearched channels, the value of the index i at that point is moved to the index p, and then step S
Go to T14.

(14) In step ST14, A
The value of the GCATT signal is increased and sent to the AGC circuit 7.
As a result, the AGC voltage increases, the output signal of the tuner 2 decreases, and the levels of the synchronizing signals of all channels decrease uniformly.

(15) Then, the operation returns to step ST3, and the steps after step ST3 are repeated. This operation loop is repeated until i becomes equal to the total number M of channels in step ST12.

(16) In steps ST11 and ST12, if the preset area is full and there are no channels left for search, the process jumps to step ST15. Then, the N CH numbers stored in the preset area are preset in the respective keys of the position tuning key 9, and the preset operation is completed.

In the above operation, the change in the contents of the preset areas A (1) to A (N) in each loop will be described, for example, for M = 8 and N = 3 as shown in FIG. It becomes like FIG.

In the first loop, CH numbers 2, 3, and 5 are stored in the preset area, and in the second loop, 2, 5, and 8 are stored in the preset area, and the preset operation ends.
Then, preset areas A (1), A (2), A (3)
The contents 2, 5, and 8 are preset in the keys K1, K2, and K3, respectively.

In each loop, step ST
The synchronization signals 7 and 8 are checked only for the channels that have been searched in the previous loop and are stored in the preset area, so the operation time is short.

Next, a second embodiment of the channel auto preset system according to the present invention will be described with reference to the flow chart shown in FIG.

In the second embodiment, of all the channels, all the channels whose radio field intensity exceeds a certain reference value are detected and stored in the convergence area, and the number of the stored channels is the position of the position tuning key 9. When the number is larger than the number, the reference value of the radio field intensity is lowered, all the channels that have exceeded the new reference value are detected from the previously stored channels, stored in the accommodation area, and the number of channels stored in the accommodation area. Is repeated until the number of positions is equal to or smaller than the number of positions, and the channel last stored in the accommodating area is preset to the position of the position selection key 9.

(1) When the program starts, first, an index k indicating the number of searched channels is set to M (step ST21).

(2) The CH numbers of all channels are stored in the memory A
(I) (i = 1 to M) to store (step ST22),
The AGCATT signal is set to 0 (step ST23).

(3) The counter index i of the channel to be searched and the count index j of the number of stored channels are both set to 0 (step ST2).
4).

(4) The index i is incremented by 1 (step ST25), and the frequency of CH number A (i) is set in the tuner 2 (step ST26). As a result, the received signal of that channel is input to the detection circuit 4. Therefore, the synchronization signal detection circuit 8 is, as described above,
The channel cut-off signal is sent to the microcomputer 10.

(5) The microcomputer 10 executes step ST27.
In, if the channel discard signal from the sync signal detection circuit 8 is "no signal", the process returns to step ST25, and if it is "signal present", the process proceeds to step ST28.

(6) In step ST28, the number j of stored channels is increased by 1, and then step ST29
Proceed to and replace the contents of A (j) with i. (7) In step ST30, steps ST25 to ST29 are repeated until i becomes equal to k.

(8) When i becomes equal to k in step ST30, the process proceeds to step ST31, where the number j of stored channels is compared with the number N of tuning keys of the position tuning key 9. . (9) If the number j of stored channels is still larger than N, the process proceeds to step ST32 and AGC is performed.
The ATT signal is increased to lower the output level of the tuner 2.

(10) Next, in step ST33,
After replacing the value of the number k of channels to be searched next time with the number j of currently stored channels, step ST
Return to 24 and repeat the above loop.

(11) While repeating steps ST24 to ST33, the number of channels stored in the memory becomes equal to or smaller than N. In that case, the flow jumps from step ST31 to step ST34, where the CH number stored in A (1) to A (N) of the memory 11 is preset in the position of the position tuning key 9, and the channel auto-preset operation ends. To do.

In the above operation, the change in the contents of the memory A (i) in each loop is represented by M as shown in FIG.
= 8 and N = 3 is shown in FIG.

That is, first, C is added to A (1) to A (8).
H numbers 1 to 8 are stored, CH numbers 2, 3, 5, and 8 are stored in A (1) to A (4) in the first loop, and 2, 5, and 8 are stored in A (1) in the second loop. ) To A (3), the preset operation ends. And A (1), A
The contents 2, 5, and 8 of (2) and A (3) are key K respectively.
It will be preset to 1, K2, K3. In addition,
In each loop, the memory contents other than A (1), A (2), and A (3) are left as they are in the previous loop.

In this second embodiment as well, in each loop, the checking of the synchronization signal in steps ST7 and ST8 is performed only for the channels stored in the memory, so the operation time is shortened.

In the above two embodiments, are all channels included?
Channel to preset to the position tuning key 9
The channel was selected by one switch operation, but the tuning key is for VHF.
To N ₁N for UHF₂Is divided into individual and frequency bands
In case of VHF band, N for N₁, M for all VHF
Number of channels M₁And N for UHF band
N ₂, M is the total number of UHF channels M₂In addition, in FIG.
The operation shown below is performed by the auto preset switch 12, respectively.
It should be executed.

Satellite broadcasting may be added to the searched frequencies. Further, when the channels are preset to each position after narrowing down to the number of positions or less, for example, the VHF channel may be preset at the same position as the position, and the UHF may be sequentially filled between them. If you can recognize the channel pattern,
If the channel preset pattern is also recognized, the channels may be preset in a specific pattern order.

[0073]

As described above, the channel auto preset system according to the present invention has the following effects.

(1) From a plurality of channels, the same number as the number of tuning keys, in the order of increasing frequency, in order of decreasing frequency,
Or, by selecting a number of channels less than that, and by making the selected channel correspond to the tuning key, unnecessary weak electric field channels are removed, and a channel with high radio field intensity is set as the number of tuning keys. It has an extremely excellent effect of being able to select a suitable number of stations and automatically preset them in a short time.

(2) The channel is selected by controlling the AGC circuit to change the gain of the tuner step by step, thereby removing unnecessary weak electric field channels by narrowing the AGC, and also by weak electric field. In an area, there is an extremely excellent effect that a channel can be selected in a state in which a channel with a weak electric field is obtained without narrowing the AGC and the channel can be preset to the number of a plurality of tuning keys.

(3) When a predetermined reference value is set and channels are selected in the order of frequency by the number of tuning keys, the reference value is changed to a larger value and the selected channel and the remaining channels Selection is repeated until there are no more channels, or the selection of channels is performed by detecting all channels that exceed a predetermined reference value in the order of frequency and if the number of detected channels is greater than the selection key. , By changing the reference value to a smaller value and repeating the process until the number of detected channels is equal to or less than the number of selection keys,
This has an extremely excellent effect that a required channel can be automatically selected and preset in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a channel auto preset system according to the present invention.

FIG. 2 shows an AGC voltage and a tuner 2 in the same system.
It is explanatory drawing which shows the relationship with the sensitivity of.

FIG. 3 is an explanatory diagram showing a change in level of each channel when an AGCATT signal is changed in the system.

FIG. 4 is a flowchart showing a first embodiment of the channel auto preset system according to the present invention.

FIG. 5 is an explanatory diagram showing a change in memory content in each loop of the embodiment.

FIG. 6 is a flowchart showing a second embodiment of the channel auto preset system according to the present invention.

FIG. 7 is an explanatory diagram showing a change in memory content in each loop in the same embodiment.

[Explanation of symbols]

 1A Auto preset system 1B Television receiver 1C Preset section 1 Antenna 2 Tuner 3 VIF circuit 4 Detection circuit 5 Video circuit 6 CRT 7 AGC circuit 8 Sync signal detection circuit 9 Position tuning key 10 Microcomputer 11 Memory 12 Auto preset switch AGCATT AGC Attenuation signal A (i) i-th memory location of memory 11 i, j, k, p index N number of tuning keys M total number of channels

Front Page Continuation (72) Inventor Toshio Amano 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (6)

[Claims] 1. A plurality of channels are selected in order of decreasing radio field strength, the number of which is equal to or less than the number of a plurality of tuning keys, and each of the selected channels is used as the plurality of tuning keys. On the other hand, the channel auto-preset system is characterized in that each channel is specified by an arbitrary tuning key. 2. The channel auto-preset system according to claim 2, wherein the channel selection is performed by controlling an AGC circuit and gradually changing a gain of the tuner. 3. The selection of the channel is performed by changing the channel selection reference value when the number of channels corresponding to the number of the tuning keys is selected, and searching for a channel that has not been selected yet. Alternatively, the channel auto-preset system described in 2. 4. The channel selection detects all channels exceeding a set reference value, and if the number of detected channels is greater than the plurality of selection keys, sequentially changes the reference value, 3. The channel auto-preset system according to claim 1, wherein the number of detected channels is the same as or smaller than that of the plurality of selection keys. 5. The channel auto-preset system according to claim 3, wherein the change of the reference value is performed toward a larger value direction. 6. The method according to claim 1, wherein the channels are selected by performing a search in an ascending order of frequency.
The channel auto preset system according to 2, 3, 4 or 5.