JPH04307404A - Magnetic data processor - Google Patents

Abstract

PURPOSE:To continue reproducing operation even when a reproducing disable state due to a reproducing magnetic head is brought about. CONSTITUTION:A rotary drum is provided with a first pair of magnetic heads 3 and 5 normally used for a recording operation and a second pair of magnetic heads 4 and 6 normally used for a reproducing operation. When the reproducing operation is disabled due to the clogging of the magnetic head with magnetic powder, etc., while reproducing the data recorded on a magnetic tape 2 by the second pair of magnetic heads 4 and 6, a reproducing path is switched from the second pair of magnetic heads 4 and 6 to the first pair of magnetic head 3 and 5. Thus, the reproducing operation can be continued without interrupting it.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head type magnetic data processing apparatus for recording and reproducing magnetic data on a magnetic tape.

0002

2. Description of the Related Art Digital audio tape devices that can write and reproduce large amounts of digital data on magnetic tape at high speed have been in the spotlight. Since this digital audio tape device can record data as digital values on a magnetic tape, there is no problem of data deterioration. For this reason, it is being used not only for personal use but also for commercial purposes at broadcasting stations and the like. Broadcasting stations use this tape device to transmit music or audio signals, but in order to avoid situations where broadcasting is interrupted due to trouble during playback, (a) and (b) are shown in Figure 7.
As shown in FIG. 2, two tape devices were synchronized at the same time to be in a playback state, and when one became unable to play, it was possible to instantly switch to the other device.

0003

[Problem to be Solved by the Invention] The non-reproducible state in the above configuration can occur, for example, when the device is used as a main device (
The problem may be caused by the phenomenon of (b) that the magnetic head of the tape device gets clogged with magnetic powder from the magnetic tape. However, when two tape drives are installed as shown in Figure 7, it is very difficult to operate them in complete synchronization. It is necessary to transfer the data, drive the drums and capstan motor servo circuits of both devices in synchronization, and also match the running phases of the magnetic tapes. In order to realize such highly synchronous operation, an expensive device configuration is required. The present invention is capable of solving the above-mentioned conventional problems, and provides magnetic data in which when one set of magnetic heads becomes unreadable, the playback path is switched within the same device and the playback operation can be continued immediately. The purpose is to provide processing equipment.

0004

[Means for Solving the Problems] The structure of the present invention for achieving the above object includes a first set of magnetic heads used for recording magnetic data on a magnetic tape, and a first set of magnetic heads used for reading magnetic data. In a magnetic data processing apparatus provided with a rotary head device each having a second set of magnetic heads, the readability detecting means detects a non-reproducible state of the second set of magnetic heads; The apparatus is characterized in that a switching means is provided for switching the reproduced data processing path from the second set of magnetic heads to the first set of magnetic heads upon detection.

[0005]

[Operation] The operation of the present invention having the above-mentioned configuration is such that when the inability detecting means detects that the second set of magnetic heads used for reproduction has become in an inoperable state due to adhesion of magnetic particles, etc. The switching means switches the reproduced data path to the first set of magnetic heads, which are normally used for recording, and thereafter data is reproduced via this magnetic head. In this way, even if the magnetic head becomes unable to reproduce, the single device can continue the reproduction operation without any audible interruption.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to the drawings. FIG. 1 is a block diagram showing an electrical system of a magnetic data processing device as an embodiment, and FIG. 2 is an explanatory diagram showing a mechanical system of the magnetic data processing device shown in FIG. The magnetic data processing device shown in FIG. 2 has a reel stand R loaded with a tape cassette 7 in which a magnetic tape 2 is wound and stored, and used to rotate the reel in the loaded tape cassette 7.
1, R2 and motors M1, M2 for rotating the reel stands R1, R2, respectively. Loading bases 9 and 10 to be pulled out, and the above-mentioned rotating drum 1 on which the magnetic tape 2 pulled out by the loading bases 9 and 10 is wound to write and read information;
It is configured to include a pinch roller 11, a capstan 12, etc., which feed and drive the drawn-out magnetic tape 2 at a constant speed.

FIG. 5 shows the arrangement of the magnetic head on the rotating drum 1 and the state of contact with the magnetic tape, and FIG. 6 shows the state of scanning of the magnetic head with respect to the magnetic tape from the recording surface side (the side where the magnetic head makes contact). ing. As shown in FIG.
They contact each other at a winding angle of 0 degrees, and write and read data while maintaining a constant relative speed. Four magnetic heads 3 to 6 are attached to the rotating drum 1 at 90 degree intervals around the rotating shaft 1a on the contact surface 1b with the magnetic tape 2. Each magnetic head 3
6 are provided with a first set of magnetic heads 3, 5, which are normally used for recording operations, and a second set of magnetic heads 4, 6, which are usually used for reproducing operations.

The magnetic head 3 and the magnetic head 6 have the same azimuth angle (A and A'), and the magnetic head 5 and the magnetic head 4 have the same azimuth angle (B and B'). This has editing functions such as read-after-write and punch-in/punch-out. As shown in FIG. 7, in the recording operation, the magnetic heads 3 and 5 of the first set alternately record magnetic data of A azimuth and B azimuth, and are delayed by 270 degrees with respect to magnetic head 3 in this embodiment. The magnetic head 6 scans the A azimuth track, and the magnetic head 4 scans the B azimuth track with an angular delay of 270 degrees relative to the magnetic head 5. Then, by checking the read signals from the second magnetic heads 4 and 6 against the recorded data, it is determined whether or not a normal recording operation is being performed. A normal reproducing operation is performed by the second set of magnetic heads 4 and 6 for reproducing alternately scanning the A azimuth track and the B azimuth track.

Next, the electrical system of the device will be explained with reference to FIG. The magnetic data processing device shown in the figure includes a main control section 20 that is the control center of the device, a clock pulse generation section 21 that generates clock pulses that serve as a reference for synchronization of control signals, and a drive section of each section. Drive system 22
, a data processing system 23 that processes data for each of the magnetic heads 3 to 6 described above, an inability detection means 24 whose details will be described later, and a storage section 25 that stores programs etc. that cause the main control section 20 to perform specific functions. and a controller 26 provided in the data input section. The drive system 22 includes a drum motor 40 that rotates the rotary drum 1, a drum motor servo circuit 39 that controls the rotational speed and rotational phase of the drum motor 40, a loading motor 27 that moves the loading bases 9 and 10, and a drum motor servo circuit 39 that controls the rotational speed and rotational phase of the drum motor 40. A loading motor driver 28 that drives the loading motor 27, reel motors 29a and 29b that rotate the reel stands R1 and R2, a reel motor driver 30 that drives the reel motors 29a and 29b, and a capstan motor that rotates the capstan 12. 31, a capstan motor servo circuit 32 that controls the rotational speed of the capstan motor 31, and a drive control section 33 that sends drive control signals to each of the servo circuits or drivers 28, 30, 32, and 39. We are prepared.

The data processing system 23 includes head amplifiers 34 to 37 that are connected to the magnetic heads 3 to 6, respectively, and amplify current so that data can be recorded and reproduced.
The system 15 consisting of the first set of magnetic heads 3 and 5 and the system 16 consisting of the second set of magnetic heads 4 and 6 are detected as being in a non-reproducible state by a non-reproducible state, which will be described in detail later. A switching unit 17 that switches the reproduction data processing path from the system 16 to the system 15, and a recording processing unit 18 and a reproduction processing unit 19 that process signals between each magnetic head 3 to 6 via this switching unit 17. We are prepared. The above-mentioned failure detection means 24 detects the second set of magnetic heads 4 used for normal reproduction operation.
, 6, and if magnetic data cannot be read by the magnetic heads 4, 6, it is determined that either the magnetic head 4 or 6 used for this reading is in a disabled state, and the above-mentioned process is performed. It has a function of sending a signal (impossibility detection signal) to the main control unit 20 indicating that magnetic data cannot be read.

The storage section 25 includes a memory 25a made of a RAM in which information can be written and read freely, and a memory driver 25b that sequentially designates and drives addresses of the memory 25a. This memory 25
A stores an application program and the like that causes the main control unit 20 to execute a specific function to be described later. In addition to functioning as a control center for the entire apparatus, the main control section 20 also controls the playback data processing path for the switching section 17 by directing the playback data processing path to the second set of magnetic heads based on the disablement detection signal output from the disablement detection means 24. 4 and 6 to the first set of magnetic heads 3 and 5, and also functions as a switching means for continuing reproduction processing of magnetic data via the magnetic heads 3 and 5. There is. In this embodiment, the main control section 20 and the switching section 17 constitute a switching means 41.

The operation of the magnetic data processing device having the above configuration will be explained. In a normal reproduction operation, tracks at azimuth angles A and B shown in FIG. 6 are scanned by the second set of magnetic heads 6 and 4, and processed by the reproduction processing section 19. During this playback operation, the failure detection means 24 detects
The signals output from the magnetic heads 4 and 6 are monitored. Here, if a reproduction signal from either one of the magnetic heads 4 or 6 is not detected, a disablement detection signal indicating a disable state is output to the main control section 20. Unplayable detection means 2
The main control unit 20 receives the failure detection signal from 4.
A switching instruction signal is sent to the switching unit 17. Switching part 1
At step 7, the switching instruction signal is input, and the second set of magnetic heads 4, 6 connected to the reproduction processing section 19 is switched to the first magnetic heads 3, 5, which are normally used for recording. The main control unit 20 continues processing the reproduced data output from the switched magnetic heads 3 and 5. In the magnetic data processing device described in detail above, the second set of magnetic heads 4 used for normal reproduction operations,
Even if playback becomes impossible due to magnetic powder from magnetic tape 2 clogging the gap between head cores 6 and 6, the first
The reproduction of data can be continued through the set of magnetic heads 3 and 5.

In the above embodiment, the rotary drum 1 is servo operated at a normal rotational speed, and when there is a problem with the magnetic heads 4 and 6 of the second set, the magnetic heads 3 of the first set are simply activated. and 5. However, there is a phase shift of 270 degrees between the magnetic heads 3 and 6 as well as between 4 and 5. For example, at the moment of this switching, as shown in FIG. The magnetic head 3 of A also scans the track that has preceded. Further, the magnetic head 5 of B scans a track that precedes the track being scanned by the magnetic head 4 of B'. Therefore, a shift occurs in the track to be reproduced at the time of switching. However, when music data is being played back and broadcast using this device, this track shift will hardly interfere with listening.

[0014] Furthermore, the above device can be used not only for reproducing music data but also for backing up large amounts of data such as on a hard disk in a computer.
When reproducing data backed up in this way, if there is a problem with the second set of magnetic heads 4 or 6 used for the reproducing operation, the first set of magnetic heads 3 and 5 By switching to playback mode, there is no need to stop the playback operation. In this case, the deviation of the playback track can be dealt with by temporarily rewinding the tape a little and continuing playback. In this case, it is possible to save the trouble of stopping the reproduction operation during data reproduction and performing head cleaning, and it is sufficient to perform head cleaning when reproduction of all data is completed.

Next, the devices shown in FIGS. 3 and 4 have a function that can eliminate the misalignment of the reproduced tracks when the magnetic heads are switched from 4 and 6 to 3 and 5 during the reproduction operation, as described above. showing something. A device with a function that can eliminate this playback track shift can prevent audio time lags caused by switching heads. For example, when synchronizing video and audio for broadcasting, the playback head can be After switching from 4 and 6 to 3 and 5, it is possible to prevent a shift between video and audio from occurring. FIG. 3 shows the drum motor servo circuit 39 and drum motor 4 of the drive system 22 shown in FIG.
It shows the relationship with 0. In the servo operation of the drum motor 40, the rotation speed of the rotating drum 1 is feedback-controlled by the FG (frequency generator) signal output from the drum motor 40, and the rotation speed of the rotating drum 1 is controlled by the PG (pulse generator) signal output from the drum motor 40. 1 rotational phase is controlled. This PG signal is output, for example, one pulse every time the rotary drum 1 rotates 360 degrees, and the phase in which the magnetic heads 3 to 6 contact the magnetic tape is controlled.

In FIG. 3, the output path of the PG signal includes a delay section 43 that delays the rotational phase of the rotary drum 1 by 270 degrees, and a path switching section 42 that switches between a path that goes through this delay section 43 and a path that does not go through this delay section 43. and. Route switching section 4
2 is configured to be switched when the above-mentioned main control section 20 sends switching instruction information. During the playback operation, when normal playback is being performed by the second set of magnetic heads 4 and 6, the PG signal path that does not pass through the delay section 43 is used, thereby operating the drum motor servo circuit 39. to control the phase of the rotating drum 1. When there is a problem with the second set of magnetic heads and the switch is made to the first set of magnetic heads 3 and 5, the servo circuit 39 is operated by the PG signal that has passed through the 270 degree delay section 43. As a result, the servo is applied so that the rotational phase of the rotary drum 1 is delayed by 270 degrees, and when the servo is in a locked state, the magnetic heads 4 and 6 are
The magnetic heads 3 and 5 now scan the tracks that were being scanned by the magnetic heads 3 and 5. Therefore, after the servo is locked, deviations in the reproduced music, audio, etc. due to switching of the magnetic head are eliminated.

In FIG. 4, the signal path of the first set of magnetic heads 3 and 5 is divided into a recording path and a reproduction path, and a buffer memory 45 is additionally provided on the reproduction path side. This buffer memory 45 delays the output of reproduced data by the time it takes for the rotary drum 1 to rotate 270 degrees. That is, since the magnetic heads 3 and 5 of the first set scan the track 270 degrees ahead of the second magnetic heads 4 and 6, the magnetic heads 4 and 6 of the second set scan the track. When the reproduction path is switched to the first set of magnetic heads 3 and 5, the buffer memory 45 can eliminate the time lag in reproduction data. Such a buffer memory 45
When the head is switched, there is no need to change the servo operation of the rotating drum 1 as in the embodiment shown in FIG. Can be played back and output without time lag. In the example shown in the figure, the magnetic heads 4 and 6 of the second set are arranged with a phase lag of 270 degrees with respect to the magnetic heads 3 and 5 of the first set, but the phase difference is 90 degrees. It can be implemented in the same way even if it is arranged with a delay.

[0018]

[Effects of the Invention] According to the present invention described in detail above, even if the reproducing magnetic head becomes unable to reproduce magnetic data, there is no need to switch between devices, and the device can be maintained almost in synchronization with the state before switching. Playback operation can continue. Therefore, there is no need to arrange two tape devices and operate them synchronously for broadcasting purposes. Also, when used for backing up computer data such as hard disk data,
When a magnetic head becomes clogged during data reproduction, there is no need to stop the reproduction operation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an electrical system of a magnetic data processing device as an example.

FIG. 2 is an explanatory diagram showing a mechanical system of the magnetic data processing device shown in FIG. 1;

FIG. 3 is a block diagram showing a partial configuration of another embodiment of the magnetic data processing device.

FIG. 4 is a block diagram showing a partial configuration of another embodiment of the magnetic data processing device.

FIG. 5 is an explanatory diagram showing the configuration of a rotating drum.

FIG. 6 is an explanatory diagram showing a scanning state of a magnetic head with respect to a magnetic tape.

FIG. 7 is a block diagram showing synchronous operation of a conventional DAT for business use.

[Explanation of symbols]

2 Magnetic tape 3,5 Magnetic head for recording 4, 6 Magnetic head for reproduction 24 Impossibility detection means 41 Switching means

Claims (1)

[Claims] 1. A rotary head device is provided, each comprising a first set of magnetic heads used for recording magnetic data on a magnetic tape and a second set of magnetic heads used for reading magnetic data. In the magnetic data processing device according to the present invention, there is provided a disabling detection means for detecting a non-reproducible state of the magnetic head of the second set, and a reproduction data processing path is changed from the magnetic head of the second set to the second set by detecting the non-reproducible state. 1. A magnetic data processing device comprising a switching means for switching between one set of magnetic heads.