KR200256712Y1 - Apparatus for storing brocasting channel in receiver - Google Patents

Abstract

The present invention relates to an apparatus for receiving a television broadcast signal, wherein a tuning unit in the apparatus according to the present invention receives a broadcasting signal, an AFT voltage detector provides an AFT voltage of a signal received in the tuning unit, and a microcomputer receives a receiving frequency of the tuning unit. While receiving the highest frequency from the lowest frequency that can be received while changing to the speed selected by the selection key to select only the channels when the preset AFT voltage corresponding to the broadcast signal is selected and stored as a broadcast channel.

That is, the present invention can vary the rate of change of the reception frequency as needed when searching for the broadcast channel of the broadcast receiving device, so that the broadcast channel can be accurately determined regardless of the strength of the received signal at the place where the receiving device is installed. It works.

Description

A broadcast channel storage device of a broadcast signal receiving device {APPARATUS FOR STORING BROCASTING CHANNEL IN RECEIVER}

The present invention relates to a device for receiving a broadcast signal by a voltage tuning method. More particularly, the present invention relates to a broadcast channel storage device of a broadcast signal receiving device capable of adjusting a search speed of a broadcast channel according to a broadcast signal strength at a location where a device is installed. It is about.

Televisions, video cassette recorders, and the like that receive television broadcasts employ a method of automatically searching for and storing in a memory only a broadcast channel through which a broadcast signal is made within a radio band for television broadcast. The user may sequentially select a broadcast channel in the memory by using a channel up / down key of the receiving device. As the broadcast channel of the memory is a channel that is actually broadcasted as described above, the user may easily select only a broadcast channel. Can be.

In order to search only the channel on which the broadcasting is performed in the television broadcasting band, it is necessary to determine whether the broadcasting signal exists in the receiving channel by sequentially changing the receiving channel of the television. In order to determine the presence or absence of a broadcast signal, two methods have been conventionally used.

The first is to determine the presence or absence of a synchronization signal. That is, the broadcast signal is composed of an audio signal and a video signal, and the horizontal signal and the vertical sync signal are included in the video signal, and the channel for detecting the sync signal determines that the broadcast signal exists.

The second is to determine the presence of a broadcast signal using the AFT (Auto Fine Tunning) voltage. The AFT voltage is used as a means for accurately detecting the reception frequency of the receiving device at the center frequency of the broadcast channel. That is, the AFT voltage generator of the receiver outputs a preset AFT voltage when the center frequency of the broadcast channel and the reception frequency of the receiver match. Therefore, only a reception channel for which a preset AFT voltage is detected may be determined as a broadcast channel.

An example of an AFT voltage for a receive channel is shown in FIG. When 3.2V (higher AFT voltage) is detected from the illustrated AFT voltage, it may be determined that the reception channel is a broadcast channel. Therefore, it is determined whether the AFT voltage of 1.8V is detected by changing the reception frequency. If the AFT voltage of 1.8V (lower AFT voltage) is not detected in the above-described process, it is determined that it is not a broadcast channel.However, if a lower AFT voltage (1.8V) is detected, the reception channel is recognized as a broadcast channel and the reception frequency is fixed. It is set as low as the value so that the reception frequency of the tuning unit 1 matches the frequency of the broadcasting channel. At this time, the detected AFT voltage is 2.5V.

On the other hand, when determining the presence or absence of a broadcast signal using the AFT voltage as described above, there is a problem in that the channel cannot be accurately determined when the received broadcast signal is weak. That is, the broadcast signal may have various intensities according to the distance between the broadcasting station or the broadcast relay station and the receiving apparatus or the surrounding environment of the receiving apparatus, and thus may be received by the receiving apparatus with extremely low intensity. In this state, as described above, the reception frequency of the reception apparatus is changed to a predetermined constant speed (in this case, the speed is set only in consideration of the normal situation in which the strength of the reception signal is normal) while determining whether the preset AFT voltage is detected. In this case, the AFT voltage cannot be detected accurately, and there is a problem that the broadcast channel can also be mistaken as a broadcast free channel.

The present invention solves this problem, and an object of the present invention is to determine the broadcast channel by determining the presence or absence of a broadcast signal with an AFT voltage, and to change the variable speed of a reception frequency according to a broadcast channel of a broadcast signal receiving apparatus as necessary. It is to provide a storage device.

In order to achieve the above object, the present invention provides a receiver for selecting and storing only a broadcast channel in a television broadcast band, comprising: a tuning unit configured to receive a broadcast signal; An AFT voltage detector for providing an AFT voltage of the signal received by the tuning unit; At least one selection key for selecting a variable receiving frequency variable rate; Receiving the highest frequency from the lowest frequency receivable sequentially while changing the receiving frequency of the tuning unit to the speed selected by the selection key, selecting only channels when a preset AFT voltage corresponding to the broadcasting signal is detected, and selecting the channel as the broadcasting channel. It has a microcomputer to store.

1 is a diagram illustrating an AFT voltage when a broadcast signal is received;

2 is a schematic block diagram of a broadcast signal receiving apparatus according to the present invention;

3 is a flowchart illustrating a driving state of a broadcast channel storage device of a broadcast signal receiving device according to the present invention;

4 is a flowchart showing the procedure of the routine L1 during the execution of the process of FIG.

<Description of the code | symbol about the principal part of drawing>

1: synchronization unit 2: micom

3: image processor 4: audio processor

5: AFT voltage detector 31: Sync detector

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

2 is a schematic block diagram of a television broadcast receiving apparatus according to the present invention.

As shown, the tuning unit 1 is configured in the receiving device of the present invention, and the tuning unit 1 is configured to receive a television broadcast signal by changing the receiving channel under the control of the microcomputer 2.

The signal received by the tuning unit 1 is provided to the image processing unit 3 and the audio processing unit 4. The image processing unit 3 demodulates the video signal of the tuning unit 1 and provides it to the receiving tube or the like, and the audio processing unit 4 demodulates the audio signal of the tuning unit 1 and provides it to the speaker.

In the image processor 3, a sync detector 31 is configured as shown, and the sync detector 31 detects a sync signal from the signal of the tuner 1 and provides it to the microcomputer 2.

An AFT voltage detector 5 is also connected to the tuner 1, and the AFT voltage detector 5 detects and provides the AFT voltage of the reception channel detected by the tuner 1 to the microcomputer 2. As shown, three selection keys 6, 7, 8 are connected to the microcomputer 2, and are received at the time of searching for a broadcast channel according to driving of the selection keys 6, 7, 8 of the microcomputer 2; Vary the speed of changing the frequency. That is, when the selection keys 6, 7, and 8 are not driven, the reception frequency is changed at a speed employed by the general reception apparatuses to search for a broadcast channel, but when the selection key 6 is driven, the general reception apparatus is changed. The reception frequency is changed to a first speed faster than the normal speed employed in the field; if the selection key 7 is driven, the reception frequency is changed to a second speed slower than the speed employed in the general reception devices; When (8) is driven, the reception frequency is changed to a third speed slower than the second speed.

3 is a flowchart illustrating an operation process of the microcomputer 2 described above.

The illustrated process is a process in which the microcomputer 2 controls the tuning unit 1 and selects and stores only a broadcast channel while sequentially receiving from the lowest reception frequency to the highest reception frequency in the broadcast band.

First, when the channel automatic search and storage mode is set (S1), the microcomputer 2 determines whether one of the selection keys 6, 7, and 8 is selected (S2). As a result of the determination in step S2, if the selection keys 6, 7, 8 have not been driven, the microcomputer 2 proceeds to step S3 to set the frequency change rate at the time of channel search to the normal speed, and the routine ( Perform L1). A detailed flowchart of the routine L1 is shown in FIG. 4 and its operation is described in detail later.

On the other hand, when the selection key 6 is driven as a result of the determination in step S4, the microcomputer 2 proceeds to step S5 to set the frequency change rate at the time of channel search as the first speed, and the selection key 7 ) Is driven (S6), the process proceeds to step S7 to set the frequency change rate at the time of channel search to the second speed, and when the selection key 8 is driven (S8), the process goes to step S9. To set the frequency change rate at the time of channel search to the third speed.

If the frequency change rate at the time of channel search is set as described above, the microcomputer 2 performs the routine L1 of FIG.

That is, the microcomputer 2 sets the lowest frequency at the receivable frequency (S11), and causes the tuning unit 1 to receive the signal of the set frequency band (S12). Then, the microcomputer 2 proceeds to step S13 to determine whether the synchronization signal has been detected by the synchronization detector 31, and if the synchronization signal is detected, proceeds to step S14, but if the synchronization signal is not detected, the step S13. Proceed to S18.

In step S14, the microcomputer 2 determines whether an upper AFT voltage is detected. When the upper AFT voltage is detected, the microcomputer 2 proceeds to step S15. In step S15, the microcomputer 2 finely increases the reception frequency of the tuning unit 1, and the width in which the reception frequency is finely increased is related to the above-described frequency changing speed. That is, if the frequency change rate is normal, the reception frequency width of the tuning unit 1 which is changed finely in step S15 becomes a normal fine predetermined width, but if the frequency change rate is one of the first to third speeds, The reception frequency of the tuning section 1 is changed to a fine predetermined width corresponding to. The change frequency of the reception frequency and the minute change width of the reception frequency of the tuning unit 1 in step S15 will be clearly understood from the following description.

The microcomputer 2 determines whether the lower AFT voltage is detected in step S16. When the AFT voltage is detected, the microcomputer 2 lowers the reception frequency of the tuning unit 1 by a predetermined value to match the reception frequency with the frequency of the broadcast channel (S17). The AFT voltage detected at this time is 2.5V as described above.

After the execution of step S17, the microcomputer 2 proceeds to step S18 to determine whether the current reception frequency is the highest reception frequency that can be received, and ends all processes if the maximum reception frequency, but not the maximum reception frequency (S19). Proceed to). In step S19, the microcomputer 2 changes the reception frequency of the tuning unit 1 in response to the frequency change speed set in the above-described steps S3, S5, S7, and S9. That is, by changing the frequency received by the tuning unit 1 to a small width or a large width, it is possible to adjust the changing speed of the receiving frequency of the tuning unit 1. Therefore, the microcomputer 2 controls the tuning unit 1 by setting the receiving frequency changing width of the tuning unit 1 to normal if the receiving frequency changing speed set in step S3 is normal, but the receiving frequency changing speed is increased. If it is one of the first to third changing speeds, the changing width of the reception frequency of the tuning unit 1 is set to a width corresponding thereto.

When the reception frequency width (receive frequency) of the tuning unit 1 is set by the above-described process, the microcomputer 2 returns to step S12.

As such, the present invention can vary the rate of change of the reception frequency as needed when searching for a broadcast channel of the broadcast reception device, so that the broadcast channel can be accurately determined regardless of the strength of the received signal at the location where the reception device is installed. It works.

Claims (3)

A receiving device that selects and stores only a broadcast channel within a television broadcast band. A tuning unit for receiving a broadcast signal; An AFT voltage detector for providing an AFT voltage of the signal received by the tuning unit; At least one selection key for selecting a variable receiving frequency variable rate; Receiving the highest frequency from the lowest frequency receivable sequentially while changing the receiving frequency of the tuning unit to the speed selected by the selection key, selecting only channels when a preset AFT voltage corresponding to the broadcasting signal is detected, and selecting the channel as the broadcasting channel. A broadcast channel storage device of a broadcast signal receiving device having a microcomputer to store. The method of claim 1, And the micom controls a change frequency of the tuner's receive frequency by varying a change width of the tuner's receive frequency. The method according to claim 1 or 2, And a synchronization detector for detecting a synchronization signal from the broadcast signal. And the micom sets the preset AFT voltage and the frequency at which the synchronization signal is detected from the broadcast signal as the broadcast channel.