JP3303282B2 - Channel auto preset system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a channel auto-preset system for automatically setting channels such as VHF, UHF and satellite broadcasting in correspondence with a position selection key in a television of a position selection system. About.

[0002]

2. Description of the Related Art Recently, the era of television multi-channels has entered the world and domestically, and the range of channel selection for viewers is expanding. However, on the other hand, if all channels are to be selected, the tuning key becomes large, handling is not easy, the price increases, and tuning takes time. Even if it is provided, various problems such as many wasteful portions actually occur.

Therefore, a channel auto-preset system using a position selection key system has recently been developed. In this method, the number of tuning keys is limited to an appropriate number, N channels are appropriately selected from all channels, and the selected channels are automatically preset to the tuning keys.

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

As a second example of the method, a method of reducing the number of candidate channels by narrowing down the AGC of the television and then performing the presetting has been put to practical use.

[0006]

However, in the first method, a low-frequency channel is preset even if the radio wave is weak, but a high-frequency channel has a limited number of tuning keys. There was a problem that the preset was not always performed even if the radio wave was strong.

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

Therefore, there is a problem that a channel of an unnecessary weak electric field is not preset, while a channel auto-preset system which can surely preset a channel desired by a viewer in a weak electric field area has to be solved. Have.

[0009]

In order to solve the above-mentioned problems, a channel auto-preset system according to the present invention comprises: (1) controlling an AGC circuit of a television;
Therefore, out of many channels,
The same number or less than the number of preset tuning keys
Automatically select a number of channels and
Auto-preset that automatically presets the channel to the tuning key
Channel auto preset system with set section
Wherein the auto-preset section is arranged in frequency order.
Perform a channel search on the
Detect channels exceeding the number and store them in the memory.
Of the channel selection key for which the number of
Stop the channel search when it exceeds the number,
Next, the reference value of the radio wave intensity is increased, and the stored channel
New channels and channels left from previous searches
The above detection and storage are performed with appropriate reference values, and are written in the memory.
Whether the number of remembered channels is equal to the number of tuning keys
Or fewer and no channels to search
The above operation is repeated until the last
Preset channel to the tuning key
It is characterized by controlling.

(2) The auto preset section is
Automatically controls the AGC circuit of the television
The gain of each channel is changed step by step,
Automatically select channels whose sync signal level is higher than a specified value.
Channels of manner selection characterized by (1) the serial mounting
It is a ru auto preset system .

[0011]

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

(1) The number of channels equal to or less than the number of tuning keys is selected from the plurality of channels in the order of frequency and radio wave intensity, and the selected channels are assigned to the tuning keys. In addition to this, unnecessary weak electric field channels can be removed, and a channel having a number of tuning keys can be preset even in a weak electric field area.

(2) The channel is selected by controlling the AGC circuit to change the gain of the tuner in a stepwise manner, thereby removing unnecessary weak electric field channels by narrowing down the AGC. In an area, a channel can be selected in a state where a channel with a weak electric field is obtained without narrowing down 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 repeatedly selecting channels for the selected channel and the remaining channels until there are no more channels, the time of the selected channel is reduced each time the number of repetitions increases. Will be able to do it.

(4) In selecting a channel, all channels exceeding a predetermined reference value are detected in descending order of frequency, and if the number of detected channels is larger than the number of selection keys, the reference value is changed to a smaller value. By repeatedly performing the operation until the number of detected channels becomes equal to or less than the number of selection keys, the search time can be reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a 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 comprises 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. , A synchronization signal detection circuit 8, a position selection key 9, a microcomputer 10, a memory 11, and an auto preset switch 12.

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

The tuner 2 is configured using 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 a channel having a high radio wave intensity,
The output voltage on a channel with a low signal strength is small.

The VIF circuit 3 converts an input signal from the tuner 2 into an intermediate frequency signal, outputs the intermediate frequency signal to the detection circuit 4, and outputs an 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 signals of three colors of R, G, and B, and outputs the signals to the CRT 6. The CRT 6 displays television images based on the R, G, and B signals from the video circuit 5.

The sensitivity of the tuner 2 depends on the AGC circuit 7
Is automatically adjusted by the AGC voltage supplied from the controller. FIG. 2 shows an example of the relationship between the sensitivity and the AGC voltage.

The AGC circuit 7 is connected to the microcomputer 10 and receives the AGC attenuation signal AG from the microcomputer 10.
Has received CATT. Thereby, 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 synchronizing signal detecting circuit 8 extracts a synchronizing signal (SYNC) from the video signal output from the detecting circuit 4, compares the level of the synchronizing signal with a certain reference value, and when the level is larger than the reference value, For example, a channel discard signal of “1”, otherwise “0”, is output to the microcomputer 10.

The level of the synchronizing signal naturally depends on the AGC circuit 7
Is changed by changing the AGC voltage. Since the AGC voltage changes according to the AGCATT signal from the microcomputer 10, the level of the synchronization signal is controlled by the microcomputer 10.

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

Next, when the AGCATT signal is set to "2" and the gain of the tuner 2 is further reduced, the level of the synchronization 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 synchronization signal detection circuit 8, and only the channel whose synchronization signal level is higher than the reference level L is determined as "signal present". , And others are configured to determine that there is no signal.

Then, in the case of FIG. 3 (A), all of the channels 1 to 8 are determined to be "signal present", and in the case of FIG. 3 (B), the channels 2, 3, 5 and 8 are determined to be "Signal present". Yes "
Thus, channels 1, 4, 6, and 7 are determined to be "no signal", and in the case of FIG.
Only 5 and 8 are determined to be "signal present".

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

This is nothing but selecting the N channels with high radio field intensity by uniformly raising and lowering the level of the synchronization signal of the channel 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
The channels are associated one-to-one with each other, and when any one of them is pressed, the corresponding channel is "preset" so as to be selected.

The microcomputer 10 sends a channel setting signal to the tuner 2 to select a channel, and sends an AGC circuit 7
A GCATT signal is sent to set an AGC voltage, and a binary signal representing the synchronization signal of the selected channel as “signal present” or “no signal” is input from the synchronization signal detection circuit 8.

The microcomputer 10 has a built-in auto-preset program, which will be described later, and starts execution when the auto-preset switch 12 is turned on.

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. These N memory locations A (1) to A (N) will be referred to as preset areas. In this preset area, the channel number that is finally preset to 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 flowchart shown in FIG.

In the first embodiment, a channel search is performed from a lower frequency to a higher frequency (the frequency may be reversed), a channel whose radio field intensity exceeds a certain reference value is detected and stored in a preset area. Search stops when the number of selected channels exceeds the number of tuning keys, and then
Raises the reference value of the radio wave intensity , detects and stores the channel stored in the preset area immediately before and the channel left in the previous search with a new reference value, and the number of channels stored in the preset area becomes the number of positions. The above operation loop is repeated until the channel becomes equal or smaller and there are no channels left unsearched, and the channel stored in the preset area is finally preset 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 necessary.

(2) Set the AGCATT signal to 0 (step ST2). The output level of the tuner 2 decreases as the number of the AGCATT signal increases.

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

(4) In step ST4, the indexes i and p are each increased by one. Note that the index p indicates the first CH number of the channel left unsearched when the preset area is full in the subsequent operation loops and there is still a channel that has not been searched.

(5) In step ST5, i is compared with N. If i is larger than N, the process goes to step ST7 to search for the channel left unsearched last time, and if not, jumps to step ST6. Search for channels in the preset area.

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

(7) Then, the synchronizing signal detecting circuit 8 generates a channel discarding signal based on the synchronizing signal from the detecting 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 rejection signal from the synchronization signal detection circuit 8 is "no signal", shifts to the next channel, and if "signal present", returns to step ST4. ST9
Proceed to.

(9) In step ST9, after increasing the number j of channels stored in the preset area by 1, 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 is full,
Channels with high radio field intensity are sequentially selected from channels with low frequencies, and preset areas A (1) to A (1)
(N).

(13) Next, the process proceeds to step ST12, and when the preset area is full, i is still M
If it is not smaller, that is, if there is still a channel that has not been searched, the value of the index i at that time is transferred to the index p, and then step S
Proceed 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 synchronization signals of all channels uniformly decrease.

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

(16) If the preset area is full and there are no channels left unsearched in steps ST11 and ST12, the process jumps to step ST15. Then, the N CH numbers stored in the preset area are preset to each of the position selection keys 9, and the preset operation ends.

In the above operation, the change in the contents of the preset areas A (1) to A (N) in each loop is represented, for example, as shown in FIG. 3 for the case where M = 8 and N = 3. As shown in 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, the preset areas A (1), A (2), A (3)
Will be preset to the keys K1, K2, and K3, respectively.

In each loop, step ST
The check of the synchronization signals 7 and 8 is performed only for the channels stored in the preset area for the channels that have been searched in the previous loop, so that 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 flowchart 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 stored channels is determined by the position of the position selection key 9. at the time of greater than the number, power
Raise the reference value of the wave intensity, detect all the channels exceeding the new reference value from the previously stored channels, store them in the accommodation area, and the number of channels stored in the accommodation area is equal to the number of positions. The above operation loop is repeated until the size becomes smaller or smaller, and the last channel stored in the accommodation 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 channels to be searched is set to M (step ST21).

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

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

(4) The index i is incremented by 1 (step ST25), and the frequency of the 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, as described above,
The channel signal is sent to the microcomputer 10.

(5) The microcomputer 10 determines in step ST27
If the channel discard signal from the synchronization 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) After increasing the number j of stored channels by 1 in step ST28, the process proceeds to step ST29.
To 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) If 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 channel selection keys of the position selection key 9. . (9) If the number j of stored channels is still larger than N, the process proceeds to step ST32, where the AGC is performed.
The output level of the tuner 2 is decreased by increasing the ATT signal.

(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
Returning to 24, the above loop is repeated.

(11) While the steps ST24 to ST33 are repeated, the number of channels stored in the memory becomes equal to or smaller than N. In that case, the process jumps to step ST34 in step ST31, where the channel numbers stored in A (1) to A (N) of the memory 11 are preset to the position of the position selection key 9, and the channel auto-preset operation ends. I do.

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

That is, initially, 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) and the preset operation ends. And A (1), A
(2), contents of A (3) 2, 5 and 8 are key K
It will be preset to 1, K2, K3. In addition,
In each loop, memory contents other than A (1), A (2), and A (3) are left as they were in the previous loop.

Also in the second embodiment, in each loop, the check of the synchronization signal in steps ST7 and ST8 is performed only for the channel stored in the memory, so that the operation time is shortened.

The above two embodiments are based on whether all channels
The channel to be preset to the position tuning key 9
The channel is selected by one switch operation, but the channel selection key is for VHF
N ₁Pcs, N for UHF_TwoAnd frequency bands
, N for the VHF band₁, M to all VHF
Number of channels M₁And N for UHF band
N _Two, M is the number M of all UHF channels_TwoThen, in FIG.
The operation shown is controlled by the auto preset switch 12 respectively.
Should be executed.

Further, satellite broadcasting may be added to the search frequency. Furthermore, when presetting to each position after narrowing down to channels equal to or less than the number of positions, 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 preset pattern of the channel 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 the plurality of channels, the same number as the number of tuning keys in the order of lower frequency and higher radio wave intensity,
Or, by selecting less channels than that, and by making the selected channels correspond to the tuning keys, unnecessary weak electric field channels are removed, and channels with high radio field intensity are reduced to the number of tuning keys. This is an extremely excellent effect that it is possible to select a total number of stations and automatically preset them in a short time.

(2) The channel is selected by controlling the AGC circuit and changing the gain of the tuner in a stepwise manner, thereby removing unnecessary weak electric field channels by narrowing down the AGC. In the area, there is an extremely excellent effect that a channel can be selected in a state where a channel with a weak electric field is obtained without narrowing down the AGC and a channel preset can be performed for several 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 selected , and stored in the memory.
Search and the remaining channels
The selection of all the channels is repeated until there are no more channels to be searched , or the selection of the channels is performed by detecting all the channels exceeding a predetermined reference value in order of frequency, storing them in a memory, and storing the stored channels. If there are more than the selection keys ,
Reference value greater than current value for a channel
The number of channels that exceed the new reference value
By repeatedly performing the same number of times as the number of tuning keys or until the number becomes smaller, a very excellent effect that a required channel can be automatically selected and preset in a short time can be obtained.

[Brief description of the 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.
FIG. 4 is an explanatory diagram showing the relationship between the sensitivity and the sensitivity.

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

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

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

[Explanation of symbols]

 Reference Signs List 1A Auto preset system 1B Television receiver 1C Preset unit 1 Antenna 2 Tuner 3 VIF circuit 4 Detection circuit 5 Video circuit 6 CRT 7 AGC circuit 8 Synchronous signal detection circuit 9 Position selection 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 number of all channels

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Amano 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-61-1114 (JP, A) JP-A Sho 61-1113 (JP, A) JP-A-1-149514 (JP, A) Japanese Utility Model Application Sho 60-116732 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03J 5/00 -7/28

Claims (2)

(57) [Claims] 1. An apparatus for controlling an AGC circuit of a television.
And, depending on the
The same or less than the number of tuning keys preset in order
Automatically select the bottom number of channels and select this selected
Auto to automatically preset channels to tuning keys
Channel auto preset with preset section
In the system, the auto-preset unit performs a channel search in order of frequency, detects a channel whose radio field intensity exceeds a certain reference value, stores the channel in a memory, and sets the number of stored channels in advance. discontinue channel search when it becomes larger than the number of channel selection key, then raise the reference value of the radio wave intensity, the stored Cha
New channels and channels left from previous searches
The detection and storage are performed with a suitable reference value, and the number of channels stored in the memory is determined by the tuning key.
Is less than or equal to the number of
The above operation is repeated until there are no more channels, and the channel stored last in the memory is tuned to the channel selection key.
A channel auto-preset system, characterized in that control is performed to preset the channel. 2. The television set according to claim 1 , wherein
Tuner gain by automatically controlling John's AGC circuit
Step by step, and for each gain, the synchronization signal of each channel
Automatically selects channels whose signal level is above a specified value
2. The channel auto-preset system according to claim 1, wherein: