JPH02304762A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To perform a quick mode shift and a quick discriminative operation among plural broadcasting systems at the time of reproducing by recording such information as a recording mode and a broadcasting system on a control track in advance utilizing a control signal and using this signal at the time of reproduction. CONSTITUTION:At the time of recording, the information of a recording mode and a broadcasting system is recorded on a magnetic tape 4 by using a control signal in advance, and at the time of reproduction, the control signal is read out by a control head 6, and converted into the original information by a code reader 7. Then, this information is outputted from a control signal output terminal 9 as a control signal for a system, and is inputted to a servo control circuit 8 for controlling a cylinder motor 3 for rotating magnetic heads 1 and 2 and a capstan motor 5 for traveling the magnetic tape 4 so as to change the reproducing mode. By this method, the information of the recording mode and the broadcasting system, etc., can quickly be detected, so that the system can correspond to those kinds of information.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention suppresses disturbances in servo control and prevents disturbances in images by quickly switching the recording mode, broadcasting method, etc. during playback. , 6 related to a magnetic recording and reproducing device having multiple recording modes [Prior Art] In a conventional magnetic recording and reproducing device, an index code or an address code is written in a control track at the start of recording or at an arbitrary time, and the control Using signals.

It was designed to make it easier to find the beginning of the tape.

An example of this type of device is the one described in Videocom January 1987 P, 40-43r, which is equipped with new search functions VISS & VASS and has improved usability.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, no consideration is given to recording information such as the recording mode and broadcasting method on the control track, and problems caused by switching the recording mode during tape playback. There were problems such as image distortion and malfunction of the circuit that determined the broadcasting system recorded on the tape.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic recording and reproducing apparatus that can quickly switch modes when reproducing a tape recorded in a plurality of modes and quickly discriminate between a plurality of broadcasting systems.

[Means to solve the problem]

The above object is achieved by recording information such as the recording mode and broadcasting system on the control track in advance using a control signal, and using that signal during playback.

[Effect]

During recording, information such as the recording mode and broadcasting system is recorded on the control track by modulating the duty of the control signal.

During playback, this information is used to control the mode switching circuit of the servo control circuit, allowing quick switching.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention, in which information on the recording mode and broadcasting system (NTSC, PAL, etc.) is recorded on a magnetic tape 4 using a control signal in advance during recording. do.

During playback, the control head 6 reads the control signal, and the code reader 7 converts it into original information.

This information is output as a system control signal from the control signal output terminal 9, and a servo control circuit 8 controls the cylinder motor 3 that rotates the magnetic head 1.2 and the capstan motor 5 that runs the magnetic tape 4. input to switch the playback mode.

According to this embodiment, it is possible to quickly detect information such as recording mode and broadcasting system, suppress disturbances in servo control, and make the system compatible with such information.

Additionally, if the recording mode information is recorded in advance a certain period of time before the recording mode actually switches, it is possible to predict the recording mode switching during playback, allowing the system to respond more quickly. I can do it.

FIG. 2 is a block diagram showing a second embodiment of the present invention, in which information such as the recording mode and broadcasting system is recorded on the magnetic tape 4 in advance using a control signal during recording. At this time, recording mode information is recorded on the magnetic tape before the recording mode is actually switched.

During playback, the control head 6 reads the control signal, and the code reader 7 converts it into original information.

The magnetic heads 1 and 2 read video information from the magnetic tape 4, the preamplifier 10 amplifies it, the signal processing circuit 11 converts it into a video signal, and the digital image memory 12 and switch 13
Enter. Digital image memory 12 stores video signals.

When the code reader 7 reads the switching of the recording mode, writing in the digital image memory 12 is stopped and the video signal stored before the switching is sent to the switch 13.

At this time, the switch 13 is switched by a control signal from the code reader 7 and outputs the video signal stored from the digital image memory 12 to the video output terminal 14.

According to this embodiment, image disturbances caused by switching recording modes or transitioning to special playback are replaced with images stored in the memory, so that a clear image can always be provided.

FIG. 3 is a block diagram showing a third embodiment according to the present invention.

When a mode switching point is reached during playback, the cycle of the control signal read from the control head 6 changes, and the capstan motor 5 that runs the magnetic tape 4 changes.
The control output of the servo control circuit 8 for controlling changes. This change is detected by the fluctuation detection circuit 15.

On the other hand, the video information read out by the magnetic heads 1 and 2 is amplified by a preamplifier 10, converted into a video signal by a signal processing circuit 11, and inputted to a switch 13 and a digital image memory 12.

The output of the fluctuation detection circuit 15 sequentially rewrites the data in the digital image memory 12 when the fluctuation in the control output of the servo control circuit 8 that controls the capstan motor 5 is small, and when the fluctuation is large, it stops writing and converts the data into a digital image memory 12. The data in the image memory 12 is converted into a video signal and outputted to the switch 13, and the switch 13 is connected to the digital image memory 12.
The video signal is outputted from the video signal output terminal 14 by switching the memory output terminal 14 so that the memory output is passed through.

According to this embodiment, mode switching can be detected even if mode information is not recorded in the control signal, and image disturbances during transition to special playback are interpolated with the output of the image memory, so that the image is always clean. Images can be supplied.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.

Video information is read from the magnetic tape 4 by a magnetic head 1.2, amplified by a preamplifier 10, and input to a signal processing circuit 11 and a level change detector 16.

The signal processing circuit 11 converts the video information into a video signal and inputs it to the digital image memory 12 and switch 13.

The level change detector 16 compares the signal from the preamplifier 10 with a reference voltage 17, and when the change is small, it sequentially rewrites the data in the digital image memory 12, and when the change is large, it stops writing and outputs a digital image. De of memory 12,
- Convert the signal into a video signal and output it to the switch 13, switch the switch 13 so that the output of the digital image memory 12 passes through, and convert the video signal to the video signal output terminal 14.
Output from.

According to this embodiment, it is determined whether the video signal is normal or not,
By using image memory, image disturbances that occur when changing recording modes or transitioning to special playback can be eliminated, and clear images can always be provided.

〔Effect of the invention〕

As explained above, according to the present invention, by recording information on the recording mode and broadcasting method on the control track, it is possible to quickly respond to the system during playback, and by combining it with a digital image memory, the above-mentioned To provide a magnetic recording and reproducing device with excellent functions, which can prevent image disturbances caused by changing the recording mode or transitioning to special reproduction even when no information is recorded, and which eliminates the problems of the above-mentioned conventional technology. be able to.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of a magnetic recording/reproducing apparatus according to the present invention, FIG. 2 is a block diagram showing a second embodiment according to the present invention, and FIG. 3 is a block diagram showing a third embodiment according to the present invention. FIG. 4 is a block diagram showing a fourth embodiment of the present invention. 1.2... Magnetic head, 6... Control head, 7... Code reader, 12... Digital image memory, 15... Fluctuation detection circuit, 16... Level change detector. Number 7! 5, Schilling hair-7 4: Food Kutaya 1st place 8 Nihitsu'-to the sword "1st floor 1st PEi lo' Fuma 5-7: Control number Horizen 2nd eye and second prisoner Taku 40 〆

Claims (1)

[Claims] 1. In a magnetic recording/reproducing device having multiple recording modes, recording mode information is recorded on a control track;
1. A magnetic recording/reproducing apparatus characterized in that the information is used to control a servo control circuit during reproduction to prevent disturbances in servo control due to changes in recording mode. 2. In the magnetic recording and reproducing apparatus according to claim 1, broadcasting system information such as NTSC, PAL, etc. is recorded on the control track, and the information is used during playback to perform servo control and signal processing corresponding to the broadcasting system. A magnetic recording/reproducing device characterized by comprising: 3. The magnetic recording and reproducing apparatus according to claim 1, wherein recording mode information is recorded on the control track, and the information is used during reproduction to control the digital image memory and to interpolate image disturbances caused by changes in the recording mode. A magnetic recording/reproducing device characterized by: 4. The magnetic recording/reproducing apparatus according to claim 1, wherein a change in the output of the servo control circuit is detected to control the digital image memory and interpolate image disturbances caused by a change in recording mode or transition to special playback. A magnetic recording/reproducing device characterized by comprising: 5. In the magnetic recording and reproducing apparatus according to claim 1, a change in the output level of the preamplifier is detected to control the digital image memory and interpolate image disturbances caused by changes in recording mode and transition to special playback. A magnetic recording/reproducing device characterized in that it is configured as follows. 6. In the magnetic recording and reproducing apparatus according to claim 1, when recording the recording mode information on the control track, the recording mode information is recorded a certain period of time before the recording mode is actually switched, so that the recording mode can be switched at the time of reproduction. A magnetic recording/reproducing device characterized in that it is configured to predict a switching point.