KR100203718B1 - Method for erasing dirty of head in video cassette recorder - Google Patents

Abstract

The present invention relates to a head decontamination method for V-shaped signal, and more particularly, to a method of decontaminating a head of a V-shaped signal, wherein a DC envelope of a current video signal provided through an A / %), The alarm message for the head contamination is displayed on the screen, then the blue screen is displayed, and the drum is driven on the basis of the driving signal of the drum driving section based on the driving control signal of the microcomputer, The blue screen is released and is reproduced from the current position, and the DC envelope for the next video signal to be reproduced is reproduced at a preset predetermined reference level Is 80% of the DC envelope for the signal), the above operation is repeated and the DC envelope for the next video signal The video tape is moved at a high speed when the head is contaminated slightly. Therefore, even if the user does not use the cleaning tape at all, the head is automatically contaminated by the high-speed movement of the tape. As shown in FIG.

Description

How to remove head decontamination

FIG. 1 is a schematic block diagram of a hardware for performing a head decontamination method of Vsial according to the present invention; FIG.

FIG. 2 is a view for explaining a process of decontaminating a head according to a preferred embodiment of the present invention; FIG.

DESCRIPTION OF THE REFERENCE NUMERALS

110: drum 120: first-

130: A / D converter 140:

150: memory 160: video signal processor

170: OSD driving part 180: Drum driving part

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video cassette recorder (hereinafter abbreviated as V-seal), and more particularly to a head decontamination method for V-seal which is suitable for removing head contamination in V-seal.

Generally, a television (TV) or a broadcasting signal provided from an external source (for example, a broadcasting signal provided from a video camera or the like) is input through an input terminal provided on the V-SOC and recorded on a video tape, It is possible to reproduce a broadcast signal recorded on a video tape.

On the other hand, if a broadcast signal recorded on a video tape is reproduced for a long time through a head in the V-shaped head, the image quality of the reproduction signal reproduced through the head is deteriorated due to contamination of the head.

In this case, the user sees a deterioration in the image quality of the reproduction signal and uses the cleaning tape to clean the head, or an alarm message displayed when the head is contaminated, and cleans the contaminated head using the cleaning tape.

However, even when slight head contamination (e.g., fine dust on a video tape or head contamination by a magnetic substance of a video tape), the user recognizes an image quality of the playback screen or an alarm message displayed on the screen, There is a troublesome problem of cleaning.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems, and it is an object of the present invention to provide a head stigma removing method of V-shaped grain which can automatically clean a contaminated head by moving a video tape at high speed, The purpose is to provide.

According to an aspect of the present invention, there is provided a head removing method of V-shaped balls for removing contamination of a head provided in a drum, the method comprising: detecting an envelope of a current image signal reproduced through the head, And comparing the envelope with a predetermined level of the envelope for the previous video signal. If the envelope for the current video signal is smaller than the predetermined level as a result of the comparison at the first stage, A second step of displaying a blue screen through an OSD driving unit after displaying the video tape, a second step of displaying a blue screen through an OSD driving unit after stopping driving of the drum driving unit, storing the current position of the video tape, A third step of moving back to the current position at a high speed, And a fourth step of reproducing the next video signal recorded on the video tape through the head, and then repeating the above steps.

Other objects and various advantages of the present invention will become more apparent from the following description of the preferred embodiments of the present invention with reference to the accompanying drawings.

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

1 is a schematic block diagram of hardware for carrying out a head decontamination method of V-SOC according to the present invention, and includes a drum 110, a first stage amplifier 120, an A / D (Audio / D converter 170, a microcomputer 140, a memory 150, an image signal processor 160, an on-screen display (OSD) driving unit 170, and a drum driving unit 180, .

1, the drum 110 includes a head to reproduce a broadcast signal recorded on a video tape on the basis of a playback drive of a drum drive unit 180 to be described later, and provides the broadcast signal to the first stage amplifying unit 120, D converter 130 and the video signal processor 160. The A / D converter 130 amplifies the reproduced signal reproduced through the head in the drum 110 to a predetermined level.

The A / D converter 130 converts an analog video signal provided from the first stage amplifier 120 into a digital video signal and supplies the digital video signal to the microcomputer 140. The microcomputer 140 converts the analog video signal supplied from the first- (For example, about 80% of the DC envelope with respect to the previous video signal) by detecting the current DC envelope in the digital video signal converted through the DC / If the envelope is smaller than a predetermined reference level, the alarm message stored in the memory 150 is fetched and a control signal for OSD processing is supplied to the OSD driving unit 170 and the playback operation of the drum driving unit 180 is performed And then generates driving control signals for moving the video tape at high speed to the drum driving unit 180, respectively.

The microcomputer 140 senses the current position of the video tape to be reproduced through the drum 110 and generates a control signal for storing the current position in the memory 150. [

Meanwhile, the memory 150 stores an alarm message for alerting the user when the head is contaminated, a preset predetermined level (about 80% of the DC envelope for the previous video signal) and the current position of the video tape, Stage amplification unit 120 to a signal capable of being displayed on a screen and provides the signal to the OSD driving unit 170. [

The OSD driving unit 170 performs an OSD process on the alert message from the memory 150 provided through the microcomputer 140 and displays the OSD message on the screen. Based on the driving control signal from the microcomputer 140, the drum driving unit 180 And generates a drive signal for rewinding or rewinding the video tape at high speed.

The operation of the V decal head decontamination method according to the present invention will now be described in detail with reference to FIG. 1 and FIG. 2 through the hardware comprising the above-described constituent members.

First, the reproduction signal reproduced through the head in the drum 110 is amplified to a predetermined level through the first stage amplifier 120 and then supplied to the video signal processor 160. At this time, the analog video signal is A / D converted (130), and then supplied to the microcomputer (140).

Then, the image signal amplified to a predetermined level through the first stage amplifying unit 120 is processed through the image signal processing unit 160 and then displayed on the screen.

The microcomputer 140 detects the DC envelope of the current video signal in the digital video signal provided from the A / D converter 130 (step 210) The reference level (e.g., 80% of the DC envelope for the previous video signal) is compared (step 220).

If the DC envelope for the current video signal is smaller than a preset reference level, the microcomputer 140 fetches an alarm message about the head contamination stored in the memory 150 And generates an alarm message for the head contamination from the memory 150 provided through the microcomputer 140 based on a control signal for the OSD process from the microcomputer 140, 170, and then displayed on a screen (step 214).

Then, the microcomputer 140 generates a control signal for displaying the blue screen and controls the OSD driver 170 based on the display control signal from the microcomputer 140 to prevent noise from being displayed on the screen A blue screen is displayed on the screen by driving (step 216).

The microcomputer 140 generates a control signal for stopping the driving of the drum and controls the driving of the drum 110 based on the driving signal of the drum driving unit 180 based on the control signal for stopping the driving from the microcomputer 140 The driving is stopped (step 218).

On the other hand, the microcomputer 140 detects a current position of the video tape provided from the drum 110 and generates a control signal for storing the detected current position. Based on a control signal for storing data from the microcomputer 140, The location is stored in the memory 150 (step 220).

Next, the microcomputer 140 generates a drive control signal (for example, high-speed rewinding for a predetermined time (for example, 3 seconds) and then fast forward to the current position) for rewinding the video tape at a high speed, The drum 110 is driven at a high speed by the drive signal of the drum drive unit 180 based on the high-speed rewinding drive control signal from the microcomputer 140. [ That is, the video tape is rewound at a high speed for a predetermined time (3 seconds) by the high-speed rewinding drive of the drum 110 (step 222).

When the video tape is rewound at a high speed for a predetermined time in step 220, the microcomputer 140 generates a driving control signal for rapidly winding the video tape to the current position of the video tape stored in the memory 150, The drum 110 is driven at a high speed by the drive signal of the drum drive unit 180 based on the fast-forward winding drive control signal from the microcomputer 140. [ That is, the fast-winding drive of the drum 110 winds the video tape to the current position at a high speed (step 224).

Next, the microcomputer 140 generates a control signal for releasing the blue screen to the OSD driving unit 170, and a blue screen displayed through the OSD driving unit 170 based on the release control signal from the microcomputer 140 (Step 226), and the microcomputer 140 generates a driving signal for reproducing the video tape to the drum driving part 180. [

Therefore, the drum 110 is driven based on the driving signal of the drum driving unit 180 based on the reproduction driving control signal from the microcomputer 140, so that the next recording signal at the current position in the recording signal recorded on the video tape is supplied to the drum (Step 228), and then returns to step 210 to repeat the above steps.

In step 212, the DC envelope for the next image signal supplied from the A / D converter 130 is converted into a DC envelope for the previous image signal stored in the memory 150 (the DC envelope for the current image signal is replaced The recording signal recorded on the video tape is reproduced through the head in the drum 110 (step 230), and then the signal processed through the video signal processor 160 is displayed on the next screen do.

As described above, the current image signal DC envelope provided through the A / D converter 130 is smaller than a preset predetermined reference level (80% of the DC envelope for the previous image signal) stored in the memory 150 The alarm message for the head contamination is displayed on the screen and then the blue screen is displayed and the drum 110 is driven based on the driving signal of the drum driving unit 180 based on the driving control signal of the microcomputer 140 The video tape is fast-rewound for a predetermined time (3 seconds), then fast-forwarded to the current position, then the blue screen is released and is reproduced from the current position, and the DC envelope for the next video signal to be reproduced is pre- (80% of the DC envelope with respect to the current video signal), the DC envelope for the next video signal is DC If it is larger than the envelope, normal playback is performed.

On the other hand, in the embodiment of the present invention, in the case of slight head contamination, the video tape is rewound at a high speed and then fast-forwarded by driving the drum driving part 180 based on the driving control signal of the microcomputer 140. However, It can easily be seen that the same result can be obtained even if the video tape is fast-forwarded and then rewound at a high speed.

Therefore, according to the present invention, since the video tape is moved at a high speed when the head is slightly contaminated, there is an effect that the head contamination can be automatically removed by the high-speed movement of the video tape even if the user does not use the cleaning tape .

Claims (4)

A head removing method of a V-shaped head for removing contamination of a head provided on a drum (110), the method comprising: detecting an envelope of a current image signal reproduced through the head based on driving of a drum driving part (180) With a predetermined level of the envelope for the first stage; If the envelope of the current video signal is smaller than the predetermined level as a result of the comparison in the first step, a message about head contamination stored in the memory 150 is displayed, and then a second step; A third step of storing the current position of the video tape after stopping the driving of the drum driving unit 180, moving the video tape at a high speed for a predetermined time, and then moving the video tape to the current position again at high speed; And a fourth step of reproducing the next video signal recorded on the video tape through the head after releasing the blue screen, and repeating the above steps. The method according to claim 1, further comprising the step of: when the envelope of the current video signal is greater than the predetermined level as a result of the comparison in the first step, displaying the video signal on the screen after the normal playback process How to remove head decontamination of V-seal. The method of claim 1, wherein the high-speed movement is a high-speed rewind operation for the predetermined time, and then the high-speed movement is fast-forwarded to the current position. The method of claim 1, wherein the high-speed movement is a high-speed rewinding operation for the predetermined time, and then the high-speed rewinding operation is performed to the current position.