KR20000026181A - Method and apparatus for searching synchronous of tv - Google Patents

Abstract

PURPOSE: A method and an apparatus for searching a synchronous of TV are provided to prevent a channel selection difference between a main channel selection and a sub channel selection from being generated and present a non necessary channel from being memorized. CONSTITUTION: An apparatus for searching a synchronous of TV includes first and second tuners (10, 20), first and second switching parts(30, 40), a main synchronous dividing circuit, a sub-synchronous dividing circuit, and a micro-computer(70). The first and second tuners output a main scene TV signal and a sub scene TV signal to a first switching part and a second switching part, respectively. The first and second switching part switch the main picture signal or a sub picture signal under the control of the micro-computer. The main synchronous dividing circuit divides a synchronous signal using an amplitude method from the switched picture signal in the first switching part. The sub-synchronous dividing circuit divides a synchronous signal using a pulse method from the switched picture signal in the second switching part. The micro-computer checks whether there is a synchronous signal or not and judges memory/deletion of a signal.

Description

Synchronous retrieval apparatus and method of TV receiver

The present invention relates to an apparatus and method for synchronizing search of a TV receiver. In particular, a TV receiver with two tuners is provided for inputting the same video signal to the main synchronizing circuit and the floating circuit separating circuit in order to enhance the synchronizing search. It relates to a synchronization check method.

In the prior art, a main signal separation circuit and a float separation circuit are separated from a video signal by using an amplitude method and a pulse method. The synchronous separation is different depending on the field strength.

At this time, during automatic channel setting, the presence / absence of the synchronous signal inputted from the floating circuit separation circuit is judged to determine the storage / clearing of the signal. There is a problem that the unnecessary channel can be stored because the state of the signal is changed.

The present invention eliminates the difference between the presence or absence of a signal at the time of main synchronization check and the presence or absence of a signal at the time of checking the floating circuit by controlling the microcomputer to input the same video signal to the main and auxiliary synchronization circuits during automatic channel setting. In order to prevent the channel difference between the channel selection and the sub channel selection, unnecessary channels are not stored.

1 is a block diagram of a synchronous retrieval apparatus of the present invention TV receiver

2 is an input selection logic diagram of a synchronous separation circuit in the present invention.

3 is a synchronization input flowchart according to the operation state of the TV receiver in the present invention

Figure 4 is a flow chart showing a synchronous search method of the present invention TV receiver

As shown in FIG. 1, the synchronous search apparatus of the TV receiver according to the present invention detects a main screen video signal by selecting a main screen TV signal from a broadcast signal RF received from an antenna ANT, and then switches the first switching unit. The sub-screen video signal is detected by tuning the sub-screen TV signal among the first tuner 10 and the broadcast signal RF received from the antenna ANT respectively to the 30 and the second switching unit 40, respectively. The second main tuner 20 outputs to the first switching unit 30 and the second switching unit 40 and the main screen or sub-screen video signals under the control of the microcomputer 70 to switch the main synchronous separation circuit. The first switching unit 30 for outputting to the 50 and the second switching unit 40 for switching the main screen or sub-screen video signal under the control of the microcomputer 70 and outputting them to the floating circuit separation circuit 60. And a main motor for separating a synchronization signal from the image signal switched by the first switching unit 30 using an amplitude method. A separation circuit 50, a floating circuit separation circuit 60 for separating a synchronous signal from the image signal switched by the second switching unit 40 using a pulse method, and the first and second circuits in automatic channel setting. The switching unit 30 controls the same video signal to be switched, and checks the presence or absence of the synchronization signal from the main motor separation circuit 50 and the floating circuit separation circuit 60 to determine the storage / deletion of the signal. It is composed of a microcomputer (70).

The synchronization search method of the present invention TV receiver implemented by the above configuration is shown in FIG. 4, and the process is as follows.

If it is not during automatic channel setting, determining whether or not there is a synchronization signal from the main synchronous separation circuit and indicating whether or not there is a synchronization signal from the floating phase separation circuit, and then displaying whether or not there is a synchronization signal from the main synchronous separation circuit; Determining whether the set mode is a quick channel setting mode or an accurate channel setting mode if the automatic channel setting is in progress; and if the fast channel setting mode indicates that the synchronizing signal is present from the main If there is synchronization in the current channel, and if it is determined that the channel is set to correct channel setting mode, the synchronization of the current channel is performed. It features.

Referring to the accompanying drawings, the operation of the synchronous retrieval apparatus and method of the present invention TV receiver configured as described above is as follows.

First, under the control of the microcomputer 70, the first tuner 10 and the second tuner 20 tune to the main screen TV signal and the sub-screen TV signal among the broadcast signals RF received from the antenna ANT. The main screen video signal V-Main and the sub screen video signal V-Sub are detected and output to the first and second switching units 30 and 40, respectively.

The first switching unit 30 and the second switching unit 40 are connected to the main screen by control signals output from a main select port and a sub select port of the microcomputer 70. The video signal or the sub-screen video signal is switched and output to the main motor separation circuit 50 and the floating circuit separation circuit 60.

At this time, when the TV receiver operates normally, a low control signal is applied to the first switching unit 30 and the second switching unit 40 from the main selection terminal and the sub selection terminal of the microcomputer 70.

As shown in FIG. 2, when the low signal is applied in the first switching unit 30, the main screen video signal is selected, and when the low signal is applied in the second switching unit 40, the sub-screen video signal is selected. .

In addition, the main synchronous separating circuit 50 separates the synchronous signal from the video signal input from the first switching unit 30 using an amplitude method and outputs the synchronous signal to the amplitude terminal of the microcomputer 70. In the synchronous separation circuit 60, the synchronous signal is separated from the video signal input from the second switching unit 40 using the pulse method and output to the pulse terminal of the microcomputer 70.

On the other hand, when the automatic channel setting mode is set by the user, the microcomputer 70 determines whether the current screen state is the PIP (Picture in Picture) on state.

As a result of the determination, when the PIP is in the ON state, the main selection terminal applies a high signal to the first switching unit 30 and the second switching unit 40.

In this case, when the high and low signals are applied, the first switching unit 30 and the second switching unit 40 select the sub-screen video signal (see FIG. 2). Since both sub-picture video signals are input to 60), the synchronization of the sub-screen video signals is input to the amplitude terminal and the pulse terminal of the microcomputer 70.

However, when the PIP is off, the microcomputer 70 applies a low signal at the main selection terminal and a high signal at the sub selection terminal to the first switching unit 30 and the second switching unit 40.

At this time, the first switching unit 30 and the second switching unit 40 selects the sub picture video signal when both the low and high signals are applied (see FIG. 2). Since all the sub-screen video signals are input to 60, the synchronization of the main screen video signal is input to the amplitude terminal and the pulse terminal of the microcomputer 70.

When the automatic channel is set as described above, the first and second switching units 30 and 40 switch the same video signal under the control of the microcomputer 70, and finally the same video in the amplitude terminal and the pulse terminal of the microcomputer 70. The synchronization of the signal is input.

4 is a flowchart illustrating a synchronous check. When the process is described, the main screen video signal is input to the main synchronous separation circuit 50 under the control of the microcomputer 70 when the automatic channel setting is not performed. Synchronization is detected, and the sub-screen video signal is input to the floating circuit separation circuit 50 to detect the synchronization of the sub-screen video signal.

On the other hand, the microcomputer 70 checks the amplitude terminal to determine whether the synchronization signal is input from the main synchronization circuit 50, and if synchronization exists, indicates that the main picture channel is synchronized, and if not, checks the pulse terminal. It is determined whether or not a synchronization signal is input from the floating circuit separation circuit 60.

At this time, if there is a synchronization signal from the floating circuit separation circuit 60, it indicates that the sub picture channel is synchronized, and if not present, the operation is terminated.

During the automatic channel setting, the same video signal is applied to the main motor separation circuit 50 and the floating circuit separation circuit 60 under the control of the microcomputer 70, and the same video signal is applied to the amplitude terminal and the pulse terminal of the microcomputer 70. Synchronization of the signal is input.

At this time, if the set mode is a fast channel setting mode, the microcomputer 70 checks the amplitude terminal to determine whether a synchronization signal is input from the main synchronization circuit 50, and if there is a synchronization signal, indicates that the current channel is synchronized. Ends.

However, when the synchronization signal is not input from the main synchronization circuit 50, the pulse terminal is checked to determine whether the synchronization signal is input from the floating circuit separation circuit 60. If synchronization exists, it indicates that the current channel is synchronized. do.

That is, when the fast channel setting mode is set, the microcomputer 70 indicates that the current channel is synchronized when the synchronization signal is present at the amplitude terminal or the synchronization signal is present at the pulse terminal to store the channel.

On the other hand, if the set mode is the correct channel setting mode, the microcomputer 70 checks the amplitude terminal and terminates the operation if there is no synchronization signal, and checks the pulse terminal to determine whether the synchronization signal exists.

At this time, if there is synchronization in the pulse terminal, it indicates that there is synchronization in the current channel, otherwise the operation is completed.

That is, in the correct channel setting mode, the microcomputer 70 indicates that the current channel is synchronized only when both the amplitude terminal and the pulse terminal exist, and stores the channel.

As described above, in the present invention, when the automatic channel is set, the same video signal is applied to the main and auxiliary separation circuits, thereby eliminating the difference between the main channel station and the subchannel station, thereby preventing unnecessary channels from being added, thereby improving the reliability of the product. It can be effective.

Claims (2)

The first tuner and the second tuner which detect the main screen video signal and the sub-screen video signal after tuning the main screen TV signal and the sub-screen TV signal among the broadcast signals received from the antenna and output them to the first switching unit and the second switching unit, respectively. And a first switching unit and a second switching unit for switching the main screen video signal or the sub-screen video signal under the control of the microcomputer, and a synchronization signal from the video signal switched by the first switching unit using an amplitude scheme. A main synchronous separating circuit, a floating circuit separating circuit for separating a synchronous signal from a video signal switched by the second switching unit using a pulse method, and the same in the first switching unit and the second switching unit in automatic channel setting. To control the video signal to be switched and to check the presence or absence of the synchronization signal from the main motor separation circuit and the floating circuit separation circuit to determine the memory / erase of the signal Synchronization search unit of the television receiver characterized in that comprises a yikeom. If it is not during automatic channel setting, determining whether or not there is a synchronization signal from the main synchronous separation circuit and indicating whether or not there is a synchronization signal from the floating phase separation circuit, and then displaying whether or not there is a synchronization signal from the main synchronous separation circuit; Determining whether the set mode is a quick channel setting mode or an accurate channel setting mode if the automatic channel setting is in progress; and if the fast channel setting mode indicates that the synchronizing signal is present from the main If there is synchronization in the current channel, and if the correct channel setting mode indicates that there is synchronization in both the main synchronous separation circuit and the floating circuit separation circuit, the present invention indicates that the current channel is synchronized. A synchronous search method of a TV receiver characterized in that.