KR19990051263A - How to automatically select a broadcast channel for a video cassette recorder - Google Patents

Abstract

The present invention relates to an apparatus for receiving an image signal, and by the channel automatic tuning mode, the microcomputer 12 detects and stores only a broadcast channel among all receivable channels of the tuner 11, and the image quality of a predetermined step by a user. If this is selected, only the broadcast channels whose number of horizontal synchronization signals that can satisfy the selected picture quality of the broadcast channels are not detected within a predetermined time period are redetected and erased from the broadcast channels.

That is, according to the present invention, only the broadcast channel that satisfies the image quality selected by the user is reset as the broadcast channel.

Description

How to automatically select a broadcast channel for a video cassette recorder

The present invention relates to a video cassette recorder, and more particularly, to a method for automatically tuning a broadcast channel of a broadcast station and selecting only a broadcast channel having a predetermined image quality from among the tuned broadcast channels.

A typical video cassette recorder is provided with a tuner, which is configured to receive general television broadcasts.

A television broadcast is a broadcast signal (video and audio signal) produced by a broadcast station for general public. The broadcast signals are modulated and transmitted to a channel assigned to each broadcast station, that is, a frequency band.

Accordingly, viewers of a video cassette recorder must tune the tuner's receive channel to one of the broadcast stations' broadcast channels in order to receive and view the broadcast signal. That is, the viewers can select and receive one of the broadcast channels by controlling the tuner to adjust its reception frequency band. Here, as described above, broadcast stations are allocated to the broadcast stations, and thus, broadcast signals are not transmitted to all channels that can be received by the tuner. Thus, when the user changes the reception channel, there may be a case where a broadcast signal is received (this channel may be a channel permitted to be broadcast to a broadcast station) while a broadcast signal is not received.

In order to alleviate this inconvenience, conventionally, a broadcast channel automatic search and storage function is added to a video cassette recorder. That is, the conventional video cassette recorder automatically changes the reception channel from the lowest receivable channel to the highest channel of the tuner when the broadcast channel automatic search and storage mode is set, and automatically searches only the channel through which the broadcast signal is received. In other words, only the channel on which the broadcast is being performed is automatically stored. When the user drives the channel up / down key, the user can turn on / down the channel only for the stored channel, that is, the channel on which the broadcast is being performed, and receive the signal of the corresponding channel. As a result, only the channel on which the broadcast is performed is always available for viewing.

On the other hand, in the conventional video cassette recorder, the determination of whether or not broadcast is being performed on the reception channel generally uses a method using a synchronization signal. That is, since the broadcast signal should normally include a synchronization signal, it is determined whether the broadcast signal is included by using whether the received signal includes a synchronization signal, particularly a vertical synchronization signal.

However, there is a problem that the method of determining whether the broadcast signal using the synchronization signal is incorrect. That is, in the case of a broadcast signal, particularly a wireless broadcast signal, there is a lot of noise caused by an external environment. Thus, there is a problem that a channel which is in a weak electric field, that is, a channel that the user cannot view, is set as a broadcast channel.

SUMMARY OF THE INVENTION The present invention has been made in view of this point, and an object of the present invention is to broadcast a video cassette recorder, which enables a user to set a broadcast channel condition so that only a broadcast channel having a predetermined image quality can be reset as a broadcast channel. It is to provide a channel automatic selection method.

The present invention for achieving the above object is a video cassette recorder having a broadcast channel automatic tuning mode for tuning only a broadcast channel by a synchronization signal, and storing image quality steps according to the number of horizontal synchronization signals within a predetermined time. Determining whether a broadcast channel auto-tuning mode is set; If the broadcast channel auto-tuning mode is set, storing only a channel where a synchronization signal is detected as a broadcast channel; Displaying a predetermined time indicating that the broadcast channel automatic tuning mode is terminated and an image quality can be selected; If a predetermined picture quality is selected within a predetermined time, sequentially receiving broadcast signals of the stored broadcast channels; And if the number of the horizontal synchronization signals that do not satisfy the selected picture quality among the received broadcast channels is not received within a predetermined time, removing the received broadcast channel from the broadcast channel.

1 is a block diagram of a video cassette recorder performing a method for automatically selecting a broadcast channel according to the present invention;

2 is a flowchart of a broadcast channel automatic selection method of a video cassette recorder according to the present invention;

<Description of the symbols for the main parts of the drawings>

11: tuner 12: micom

13 synchronization detection unit 14 recording processing system

15 deck 16: regeneration treatment system

17: OSD unit 18: modulator

19: key metrics

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a video cassette recorder for performing an inter-channel interference prevention method according to the present invention, including a tuner 11, the tuner 11 of the channel corresponding to the tuning signal of the microcomputer 12; It is configured to receive a signal and apply it to the synchronization detector 13 and the recording processing system 15.

The synchronization detector 13 detects a synchronization signal, that is, horizontal and vertical synchronization signals, from the signal of the tuner 11 and applies it to the microcomputer 12.

On the other hand, the recording processing system 14 is configured to record the received broadcast signal of the tuner 11 and apply it to the deck 15 according to the recording control signal of the microcomputer 12, and the deck 15 has a microcomputer 12 It is configured to drive in the drive mode according to the control of). That is, the deck 15 drives in the recording mode when the recording control signal is applied from the microcomputer 12 to record the broadcast signal of the recording processing system 14 on the magnetic tape, and when the reproduction control signal is applied from the microcomputer 12 It is configured to drive in the reproduction mode to read out the broadcast signal recorded on the magnetic tape and apply it to the reproduction processing system 16.

In addition, the deck 15 of the present invention can be driven in various modes such as a fast play mode and a pause mode according to the drive control signal from the microcomputer 2, but the drive mode of the deck and the drive thereof. The mechanism is a technical matter that can be easily understood by those skilled in the art of the present invention, the detailed description thereof is omitted.

The signal processed and output by the reproduction processing system 16 and the received image signal of the tuner 11 are applied to the OSD unit 17, and the OSD unit 17 corresponds to a predetermined OSD control signal of the microcomputer 12. And a text signal or a blue back signal are mixed with the video signals of the tuner 11 and the reproduction processing system 16 and output.

On the other hand, the OSD unit 17 is connected to the modulator 18, the modulator 18 modulates the output signal of the OSD unit 17 to a predetermined channel (3 or 4 channels) under the control of the microcomputer 12 Or output directly to an original state without modulating the input video signal.

Meanwhile, as shown, the key matrix 19 is connected to the microcomputer 12, and the function key (channel selection key (consisting of numeric keys), channel up / down key, power on / off key) of the key matrix 19 is connected. , A playback key, a modulator modulation channel selection key, and the like), and the microcomputer 12 performs the operation described below in accordance with the driving of these keys.

2 shows an operational flowchart of a microcomputer 12 for carrying out the present invention.

As shown in the figure, the microcomputer 12 determines whether the channel automatic tuning mode is set by pressing the channel automatic tuning key (S1). When the channel automatic tuning mode is set, the microcomputer 12 performs the same channel automatic tuning mode as in the prior art (S2). That is, the received channel of the tuner 11 is changed and received from the lowest channel to the highest channel of the tuner 11, and among the received signals, only the channel in which the synchronization signal is detected by the synchronization detector 13 is set as a broadcast channel. To save. Since this process is a conventional technology as described above, a detailed description thereof is omitted.

In step S2, the microcomputer 12 performs the channel auto tuning mode. Then, the microcomputer 12 proceeds to step S3. The OSD unit 17 terminates the channel auto tuning mode and selects the desired picture quality according to the set broadcast channel. OSD text signal is output.

The OSD text signal allows the user to select a picture quality using the keys of the key matrix 19. For example, one or three levels can be distinguished from each other by the degree of image quality. Herein, the microcomputer 12 of the present invention determines the video quality of the broadcast channel as follows. As described above, the video signal includes a synchronization signal, for example, 60 horizontal synchronization signals per second. However, since the horizontal synchronization signal may be lost due to external noise or the like, the degree of image quality may be determined by the number of times the horizontal synchronization signal is detected per second. For example, the first level of image quality is when at least 58 or more horizontal sync signals are detected per second, the second level of image quality is detected by 56-57 times per second, and the third level of image quality is detected by 54 to 56 per second. It can be set, which can be adjusted as needed.

After performing step S2, the microcomputer 12 determines whether or not the key signal for selecting the image quality as described above is applied from the key matrix 19 within the predetermined time (S4, S5). Such a key signal can be used as a key signal for selecting the image quality, for example, the numeric key 1 of the key matrix 19 in the first stage of image quality, the numeric keys 2 and 3 of the key matrix 19 in the stage of image quality in the third stage. There will be.

When the user selects one of the numeric keys 1, 2, and 3 by performing steps S4 and S5, the microcomputer 12 tunes the tuning signal corresponding to the lowest channel of the broadcast channel tuned in step S2. Applies to (11) to cause the tuner 11 to receive the signal of the broadcast channel (S7). Then, the microcomputer 12 determines whether the number of horizontal synchronization signals per second applied from the synchronization detector 13 corresponds to the set quality level (S8), and if so, proceeds to step S10. If the number of horizontal synchronization signals per second applied by the synchronization detector 13 does not correspond to the set level of image quality, the tuner 11 deletes the current reception channel from the broadcast channel (S9). That is, when the broadcast channel being received by the tuner 11 does not reach the user-defined quality, the tuner 11 deletes the stored broadcast channel.

In addition, the microcomputer 12 proceeds to step S10 to determine whether the channel being tuned by the tuner 11 corresponds to the highest channel among preset broadcast channels. If not, the user tunes to all broadcast channels by changing the reception channel of the tuner 11 to the next broadcast channel of the broadcast channel being tuned by the tuner 11 among the preset broadcast channels (S11) and then proceeding to step S8. It is determined whether a video signal satisfying the selected picture quality is received and the unsatisfied broadcast channels are deleted from the broadcast channel.

Meanwhile, as a result of the determination of steps S4 and S5, when the numeric keys 1, 2 and 3 for selecting the image quality are not pressed, the microcomputer 12 outputs the OSD text signal output of the OSD unit 17 in step S6. You quit and end the whole process.

As can be seen from the above description, in the present invention, broadcast channels that receive a broadcast signal that does not satisfy the user-selected picture quality among the broadcast channels tuned by the channel tuning mode are automatically deleted so that the user has the selected picture quality. The effect is that only channels can be tuned.

Claims (1)

A video cassette recorder having a broadcast channel automatic tuning mode in which only a broadcast channel is tuned by a synchronization signal, and the quality level is divided and stored according to the number of horizontal synchronization signals within a predetermined time. Determining whether the broadcast channel auto-tuning mode is set; If the broadcast channel automatic tuning mode is set, storing only a channel where the synchronization signal is detected as a broadcast channel; Displaying a predetermined time that the broadcast channel automatic tuning mode is terminated and an image quality can be selected; If a predetermined picture quality is selected within the predetermined time, sequentially receiving broadcast signals of the stored broadcast channels; And if the number of the horizontal synchronization signals that do not satisfy the selected picture quality among the received broadcast channels is not received within a predetermined time, erasing the received broadcast channel from the broadcast channel. .