KR19980041553A - Operation Control Method of Auto Head Cleaner Using Synchronization Signal - Google Patents

Abstract

The present invention relates to an operation control method of an autohead cleaner using a synchronization signal. In particular, when a tape is played, a first step (101 to 101) of detecting a signal level of a synchronization signal from a video signal reproduced by the synchronization signal detector 28 is performed. 102, the second step 103 of comparing the signal level of the synchronization signal detected in the first step with a reference value, and if the signal level of the synchronization signal detected in the second step is smaller than the reference value, the autohead cleaner ( The third step (104 to 107) to remove the foreign matter stuck to the video head 16 by driving the 27 for a predetermined time and the synchronization signal despite the drive of the autohead cleaner 27 in the third step If the signal level is smaller than the reference value, the fourth step 108 of outputting an OSD to notify the viewer of a tape defect is indicated. Therefore, the video head 16 may not be driven due to excessive driving of the autohead cleaner 27. It can prevent hair and damage.

Description

Operation Control Method of Auto Head Cleaner Using Synchronization Signal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation control method of an autohead cleaner for removing foreign substances from a video head. In particular, the present invention relates to a synchronization signal for driving an autohead cleaner according to a signal level of a synchronization signal detected in a video signal reproduced from a tape. It relates to an operation control method of the used auto head cleaner.

Generally, one end of a video tape has an audio track on which an audio signal is recorded, and the other end has a control track on which a control signal is recorded, and the video signal is recorded in a video track between the audio track and the control track. The video track is formed obliquely on the tape, and generally one field of video signal is recorded on one video track. On the other hand, the video signal is converted into an FM signal and recorded unbiased in the video track. Therefore, even in a small VCR, since the recording frequency ranges from 100 KHz to 6 MHz, a rotating head method is generally used to record high frequency signals. At this time, the relative speed between the head and the tape reaches 11 kW, and the tape recording wavelength ranges from 100 m to 2 m, but most of the video signal energy is actually concentrated at 5 to 3 m.

As described above, as the video signal magnetic recording method uses high frequency, high speed, and short wavelengths close to the limits of magnetic recording technology, the performance of the video head for reproducing the video signal plays a major role in determining the performance of the VCR. Therefore, in order to restore the video signal magnetically recorded on the video tape to the best state, the state of the video head must be maintained at the best state. To do this, the VCR is equipped with an autohead cleaner that automatically removes debris from the videohead.

However, the conventional autohead cleaner is driven every time the VCR is powered to clean the head. Therefore, there is a problem in that even if the head condition is good, since the head is wiped, the head wears out quickly and the life of the head is shortened. In addition, if the video head does not reproduce the video signal in the best condition even though the auto head cleaner is driven, the viewer cannot recognize whether the auto head cleaner is normally operated, and then restarts the auto head cleaner to accelerate the wear of the head. There was this.

Accordingly, the present invention has been invented to solve the above problems, and since the autohead cleaner is driven in accordance with the signal level of the synchronization signal detected from the video signal reproduced from the tape, the synchronization signal can prevent rapid wear of the head. It is an object of the present invention to provide a method for controlling the operation of an autohead cleaner.

Another object of the present invention, by outputting the OSD (On-Screen Display) to inform the viewer of the operating state of the auto head cleaner, the auto signal using a synchronization signal that can prevent the wear of the head due to excessive operation of the auto head cleaner It is to provide a method of controlling the operation of the head cleaner.

In order to achieve the above object, the present invention provides a method for controlling the operation of an autohead cleaner for removing foreign substances from a video head. When the tape is played, the signal level of the sync signal is adjusted from the played video signal through the sync signal detector. The first step of detecting, the second step of comparing the signal level of the synchronization signal detected in the first step with a reference value, and the autohead cleaner if the signal level of the synchronization signal detected in the second step is smaller than the reference value. A third step of removing foreign matters stuck to the video head by driving for a predetermined time; and when the signal level of the synchronous signal is smaller than the reference value in spite of the operation of the autohead cleaner in the third step, an OSD is output to output the state of the tape. And a fourth step of notifying the viewer of the defect.

1 is a block diagram showing the configuration of a TVCR to which the present invention is applied;

2 is a flowchart illustrating an autohead cleaner operation control method using a synchronization signal according to the present invention.

Explanation of symbols on main parts of drawing

11: antenna 12: tuner

13 video tape playback unit 14 audio head

15: audio signal processor 16: video head

17: video signal processing unit 18: switching unit

19: voice signal processor 20: voice signal amplifier

21 speaker 22 video signal processing unit

23: video signal amplifier 24: the water tube

25: head drum motor 26: capstan motor

27: auto head cleaner 28: sync signal detector

29: microcomputer 30: timer

31: OSD generator

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

1 is a block diagram schematically showing a configuration of a TVCR to which the present invention is applied. A switching unit includes a tuner 12 that selectively receives a broadcast signal desired by a viewer through an antenna 11 among broadcast signals output from a broadcasting station. It is connected to (18). In addition, a video tape reproducing unit 13 for reproducing a signal recorded on a video tape is connected to the switching unit 18. The switching unit 18 is connected to a tuner 12 or a video tape reproducing unit 13. One side of the output signal is switched to the next stage.

The video tape reproducing unit 13 includes an audio head 14 and a video head 16 for converting audio and video signals recorded on a tape into electrical signals, respectively, and the audio head 14 and the video head 16. And an audio signal processing unit 15 and a video signal processing unit 17 for demodulating or amplifying the electrical signal converted into the audio signal and the video signal. The head drum motor 25 to rotate, the capstan motor 26 which drives a tape at a constant speed, and the auto head cleaner 27 which removes the foreign material stuck to the video head 16 are provided. On the other hand, the audio signal processor 19 and the video signal processor 22 amplify and detect the output signal of the tuner 12 or the video tape reproducing unit 13 switched by the switching unit 18 to detect the audio signal and the image. Extract each of the signals. The extracted audio signal and the video signal are amplified by the audio signal amplifier 20 and the video signal amplifier 23 to be output to the outside through the speaker 21 and the water pipe 24.

In addition, the synchronization signal detector 28 detects a signal level of the synchronization signal included in the video signal output from the video tape reproducing unit 13 and provides the signal to the microcomputer 29. The microcomputer 29 that controls each component of the TVCR compares the output signal of the synchronization signal detector 28 with a reference value, and accordingly, the autohead cleaner 27 is operated while the timer 30 counts a predetermined time. While driving, the OSD generator 31 is controlled to output an OSD signal indicating the operation state of the autohead cleaner 27 to the image signal processor 22.

2 is a flowchart illustrating an operation control method of an autohead cleaner using a synchronization signal according to the present invention applied to the TVCR configured as described above, in which an autohead cleaner operation control method is used to remove foreign substances from the video head 16. When the video tape is reproduced, the first step of detecting the signal level of the synchronization signal from the video signal reproduced by the synchronization signal detector 28 and comparing the signal level of the synchronization signal detected in the first step with a reference value The second step and the third step of removing the foreign matter stuck to the video head 16 by driving the autohead cleaner 27 for a predetermined time when the signal level of the synchronization signal detected in the second step is less than the reference value If the signal level of the synchronization signal is smaller than the reference value in spite of the driving of the autohead cleaner 27 in the third step, the OSD is outputted and the tape is in a bad state. It shows that performing the fourth step to inform the viewer.

According to the present invention configured as described above, when the video tape is reproduced, the synchronization signal detection unit 28 detects the signal level of the synchronization signal included in the reproduced video signal and applies it to the microcomputer 29 (101 to 102). Accordingly, the microcomputer 29 compares the signal level of the detected synchronization signal with a reference value (103). If the signal level of the detected synchronization signal is greater than the reference value, the microcomputer 29 determines that the video head 16 operates normally. If the signal level of the detected synchronization signal is smaller than the reference value, the foreign material is caught in the video head 16 and the tape is stuck. It is determined that the video signal cannot be reproduced in the best condition. Therefore, the microcomputer 29 drives the autohead cleaner 27 while the timer 30 counts a preset time to remove foreign substances stuck in the videohead 16 while simultaneously outputting an OSD signal indicating that the autohead cleaner is in operation. The OSD generation unit 28 is controlled to output (104 to 107).

On the other hand, even though the auto head cleaner 27 is driven as described above, if the signal level of the synchronization signal detected by the synchronization signal detection unit 28 is smaller than the reference value, the microcomputer 29 determines that the tape is in a bad state. Accordingly, the microcomputer 29 controls the OSD generating unit 28 to output an OSD signal indicating that the tape state is bad (108), and stops the operation of the autohead cleaner 27 (109).

As described above, the present invention drives the autohead cleaner in accordance with the signal level of the synchronization signal detected from the video signal reproduced from the tape, thereby preventing rapid wear of the head compared to the conventional autohead cleaner operation method. In addition, by outputting an OSD (On-Screen Display) to inform the viewer of the operating state of the autohead cleaner can prevent the wear of the head due to excessive operation of the autohead cleaner.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (2)

In the auto head cleaner operation control method for removing the foreign matter stuck to the video head 16, A first step (101 to 102) of detecting a signal level of the synchronization signal from the video signal reproduced by the synchronization signal detection unit 28 when the video tape is reproduced; A second step (103) of comparing the signal level of the synchronization signal detected in the first step with a reference value; If the signal level of the synchronization signal detected in the second step is less than the reference value, the third step (104 to 107) of driving the autohead cleaner 27 for a predetermined time to remove the foreign matter stuck to the video head 16 ; And a fourth step 108 of notifying the viewer of the tape defect by outputting an OSD if the signal level of the synchronization signal is smaller than the reference value despite the driving of the autohead cleaner 27 in the third step. Operation method of auto head cleaner 2. The autohead using a synchronization signal according to claim 1, wherein in the third step, an on-screen display (OSD) is output when the autohead cleaner is driven to notify a viewer of an operation state of the autohead cleaner 27. Cleaner operation control method.