JP2000173003A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic recording and reproducing device for preventing the generation of the distortion of an image at the consecutive recording position or assemble editing position of a magnetic tape, and for obtaining a signal with high quality equivalent to that at a normal position. SOLUTION: A magnetic recording and reproducing device is provided with a head drum 17 equipped with recording heads 13 and 15 for recording helical tracks 2-12 in a magnetic tape 1 and erasure heads 14 and 16 for erasing the helical tracks 2-12 at positions prior to the recording heads 13 and 15, a recording circuit 26 for outputting a recording signal to the recording heads 13 and 15, a deleting circuit 27 for outputting a deletion signal to the erasure heads 14 and 16, and a control circuit 28 for controlling the deleting circuit 27 and the recording circuit 26. The erasure heads 14 and 16 are constituted so that areas beyond the helical tracks whose recording is ended by the recording heads 13 and 15 can be deleted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a rotary head type magnetic recording / reproducing apparatus used for recording and reproducing a magnetic tape.

[0002]

2. Description of the Related Art In recent years, as digitalization of magnetic recording has progressed, narrower tracks in broadcast VTRs and thinner magnetic tapes have been developed in parallel.
Even in such a situation, the image is not disturbed in the magnetic tape splicing and assemble editing at each time of the new and old times, that is, the image is not disturbed at the splicing position and the assemble editing position where various errors are likely to accumulate. is needed.

A head drum 17 provided in a general magnetic recording and reproducing apparatus has a recording head 13 for recording a helical track on a magnetic tape, as schematically shown in a plan view of FIG. 15 are disposed at positions facing each other at an interval of 180 °, and the erasing head 1
Each of the erasing heads 4 and 16 is disposed at a position delayed by a predetermined angle along the rotation direction 18, and the erasing heads 14 and 16 are ahead of the recording heads 13 and 15 by two tracks, for example. Where the helical track is to be erased.

Therefore, the magnetic tape pattern at the end of recording in the magnetic recording / reproducing apparatus is as shown in FIG. 8, and the helical tracks 2 to 7 recorded on the magnetic tape 1 at the new time and the helical tracks recorded at the old time. Track 8
Of the helical tracks 8 to 12, a slit 21 is generated in the old helical track 8 because a part of the helical track 7 is erased as the wide erasing head 16 erases the helical track 7. In FIG. 8, reference numeral 19 denotes the running direction of the magnetic tape 1, and reference numeral 20 denotes the recording heads 13, 15 and the erasing head 1.
4, 16 scanning directions are shown, respectively.

That is, in a conventional magnetic recording / reproducing apparatus,
As can be seen from FIG. 9 showing the positional relationship between the magnetic tape pattern and the magnetic head, the erasing head 16 disposed at a position two tracks ahead of the recording head 15 erased the helical track 7 at the old time. Then, the erasing operation is stopped, and after two tracks, the recording head 15 records the helical track 7 at a new point in time and the recording operation ends, and the timing of the magnetic head at the end of the recording operation is as shown in FIG. It has become. In FIG. 10, the recording head 13 is controlled by a recording signal of RecA,
It is assumed that the recording head 15 is controlled by the recording signal of RecB, the erasing head 14 is controlled by the erasing signal of FEA, and the erasing head 16 is controlled by the erasing signal of FEB. High in FIG. The erasing state and the Low state indicate the cutoff state.

The erasing head 16 at this time stops the erasing operation after the recording head 15 erases the helical track 7 to be recorded last. When erasing is performed, even a part of the adjacent helical track 8 is erased, so that the helical track 8 has a slit 21 as shown in FIG.

Further, when splicing and assembling and editing of the helical track 8 subsequent to the helical track 7 are executed, the positional relationship between the magnetic tape pattern and the magnetic head is as shown in FIG. That is, first, the erase head 14 is moved to the old helical track 8.
Is erased, and the recording head 13 records the helical track 8 at the new time.
6 erases the helical track 9 at the old time and the recording head 15 records the helical track 9 at the new time. As a result of these operations being repeated, the helical tracks 8 to 12 record the data at the new time. It was done.

At this time, as shown in FIG. 12, the timings of the magnetic heads are as follows. At the start of recording, the erasing heads 14 and 16 become High first to start the erasing operation, and the recording heads 13 and 15 start to operate at 2 times. Helical trucks 8 to 12 after going high after being delayed by the truck
When erasing the helical track 8 at the old time at the start of recording, even the part of the helical track 7 at the new time adjacent to the new helical track 7 by the wide erase head 14 is to be started. Is erased,
The helical track 7 has a slit 22 as shown in FIG.

Further, it is necessary to consider the bending of the helical track or the like in connection shooting or assemble editing at the time of compatibility, and the positional relationship between the magnetic tape pattern and the magnetic head at this time is as shown in FIG. That is, when the helical truck is bent, not only the cut 23 on the helical truck 7 occurs, but also the width of the helical truck 7 becomes narrower.
As a result, the helical truck 8 is left unerased, and if the width of the helical truck 7 is narrow, the performance is deteriorated. In the helical track 8 in which the unerased data 24 has been generated, since the old data having the same azimuth angle remains, the same azimuth signal leaks into the original signal at the time of reproduction. This will result in performance degradation.

[0010]

As described above,
In recent years, despite the fact that it is required not to cause image disturbance in splicing and assembling editing of magnetic tapes, the conventional magnetic recording / reproducing apparatus has not been able to meet such demands. It is.
The present invention has been conceived in order to overcome such a situation, and to prevent the image from being disturbed at the splicing position and the assemble editing position while the track is becoming narrower. It is an object of the present invention to provide a magnetic recording / reproducing apparatus configured to obtain a high-quality signal similar to that described above.

[0011]

In a magnetic recording / reproducing apparatus according to the present invention, in splicing and assembling editing of a magnetic tape, an area above a helical track at which a recording head finishes recording, that is, a base erases a base. Or a configuration in which at least one helical track is erased from the shifted position. Therefore, according to these configurations, even if a slit or an unerased portion occurs at the splicing position of the magnetic tape or at the assembling edit position, there is no inconvenience because it is plain, and the splicing and assembling with higher precision are performed. As a result of being able to edit, high reliability is obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic recording / reproducing apparatus according to a first aspect of the present invention includes a recording head for recording a helical track on a magnetic tape, and an erasing head for erasing the helical track at a position preceding the recording head. A head drum comprising: a recording circuit that outputs a recording signal to the recording head; an erasing circuit that outputs an erasing signal to the erasing head; and a control circuit that controls the erasing circuit and the recording circuit. Wherein the erasing head is configured to erase an area above a helical track at which the recording head ends recording.

A magnetic recording / reproducing apparatus according to a second aspect of the present invention includes a recording head for recording a helical track on a magnetic tape, and an erasing head for erasing the helical track at a position preceding the recording head. A head drum, a recording circuit that outputs a recording signal to the recording head, an erasing circuit that outputs an erasing signal to the erasing head,
A control circuit for controlling the erasing circuit and the recording circuit, wherein the erasing head erases an area above a helical track at which the recording head ends recording and a helical track at which the recording head starts recording. The erasing is started from a position preceding the track.

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

FIG. 1 is a plan view schematically showing the structure of a head drum provided in a magnetic recording / reproducing apparatus according to an embodiment.
FIG. 2 is a block diagram showing a circuit configuration of the head drum, and FIG.
FIG. 4 is an explanatory diagram showing a magnetic tape pattern at the end of recording, and FIG. 4 is an explanatory diagram showing a positional relationship between the magnetic tape pattern and the magnetic head at the end of recording. FIG. 5 is an explanatory diagram showing the timing of the magnetic head at the end of the recording operation, and FIG. 6 is an explanatory diagram showing the positional relationship between the magnetic tape pattern and the magnetic head at the start of the recording.
Is an explanatory diagram showing the timing of the magnetic head at the start of the recording operation. In addition, in FIGS. 1 to 7 according to the embodiment, FIGS.
3 and the corresponding parts and portions are denoted by the same reference numerals.

The magnetic recording / reproducing apparatus according to the present embodiment
A head drum 17 as shown in FIG. 1 is provided. The head drum 17 is composed of a pair of recording heads 13 and 15 for recording a helical track on the magnetic tape 1.
A structure in which the erasing heads 14 and 16 are arranged at positions facing each other at a distance from each other and are arranged at positions delayed by a predetermined angle along the rotation direction 18, that is, the erasing heads 14 and 16 , 16 have a structure for erasing a helical track at a position preceding the recording heads 13, 15 by two tracks, for example. The erasing heads 14 and 16 here are configured to erase the area above the helical track where the recording heads 13 and 15 stop recording, or the area above the helical track where the recording heads 13 and 15 end recording. As well as
The recording heads 13 and 15 start erasing from a position preceding the helical track where recording is started.

As shown in FIG. 2, each of the recording heads 13 and 15 and the erasing heads 14 and 16 at this time has a head amplifier 25 and a recording circuit 26.
The recording signals of RecA and RecB are supplied to the recording heads 13 and 15 from the
, FEA, F for each of the erase heads 14, 16
An EB erase signal is to be supplied. In addition,
Reference numeral 28 in FIG. 2 indicates a control circuit, and the control circuit 28
And the recording head 1 associated with controlling the erase circuit 27
The operation of each of the erase heads 3 and 15 and the erase heads 14 and 16 is controlled.

Therefore, the magnetic tape pattern at the end of recording in the magnetic recording / reproducing apparatus is as shown in FIG. 3, and helical tracks 2 to 12 are recorded on the magnetic tape 1. That is, in this case, the helical tracks 2 to 7 recorded at the new time, the helical tracks 8 and 9 from which the data at the old time have been erased, and the helical tracks 10 to 12 recorded at the old time. Exist continuously, and the helical truck 1 at the time of the old
At 0, a slit 21 is generated because a part of the helical track 9 is erased as the helical track 9 is erased by the wide erase head 16. In the case of recording for the first time on an unused magnetic tape 1, a so-called virgin tape, there is no slit 21 because there is no helical track at the old time. , The trajectory of the erasure remains.

That is, in the magnetic recording / reproducing apparatus according to the present embodiment, as can be seen from FIG. 4 showing the positional relationship between the magnetic tape pattern and the magnetic head at the end of recording,
The erasing head 16 disposed at a position two tracks ahead of the recording head 15 erases each of the helical tracks 3, 5, 7, and 9 which are the old data, and then stops the erasing operation. After the track, the recording head 15 records the helical tracks 3, 5, and 7 at the new point in time, and the recording operation ends. At this time, the magnetic tape 1 moves in the running direction 19 and the recording head 13 , 1
5 and the erasing heads 14 and 16 each have a scanning direction of 20.
Are moving along.

Incidentally, although not shown, each of the recording head 13 and the erasing head 14 is
And the erasing head 16 is disposed in the same positional relationship as the erasing head 16, and the erasing head 14 is located at one time before the helical tracks 3, 5, 7, 9 to be erased by the erasing head 16 and the old helical tracks 2, 4. , 6, 8 are erased, and the recording head 13 records the helical tracks 2, 4, and 6 at the new point in time two tracks later. Therefore, in the state shown in FIG. 3, the recording of the data at the new point in time on the helical track 7 has been completed.

The timing of the magnetic head at the end of the recording operation is as shown in FIG. 5. High in FIG. 5 indicates a recording state or an erasing state, and Low indicates a low state.
Indicates a cutoff state. That is, RecA at this time
(Recording head 13) and RecB (recording head 15) alternately repeat High and Low, and Rec.
After the A (magnetic recording head 13) goes High and records the helical track 6, the recording at the new time ends as RecB goes High and records the helical track 7. On the other hand, the erasing heads 14 and 16 are disposed at positions ahead of the recording heads 13 and 15 by two tracks, and the FEA (erasing head 14) and F
EB (erasing head 16) is RecA (recording head 13)
And RecB (recording head 15) become High and Low, respectively, so that the erasing head 14 erases the helical track 8 and the erasing head 16 erases the helical track 9 at the last time. Ends the recording operation.

Therefore, in splicing and assembling and editing of the magnetic tape 1, when recording is newly started from the helical track 8, when the helical track 8 is newly recorded, the recording heads 13 and 15 are used. The area above the helical track 7 where recording is completed, that is, the helical tracks 8 and 9 serving as the base
Since the blank has been erased by the steps 4 and 16 and has become plain, the slit 22 as shown in FIG. 11 does not occur. Further, even if the helical tracks 8, 9 at the new time point are shifted due to a mechanical error or the like, the helical tracks 8, 9 at the old time point are not left unerased. Inconveniences due to the existence of unerased parts will not occur.

That is, when the splicing of the helical track 8 subsequent to the helical track 7 and the assembling edit are executed, the recording is started by the recording head 13 from the helical track 8, and the magnetic tape pattern at this time is started. The positional relationship between the magnetic head and the magnetic head is as shown in FIG. First, a slit 21 is formed in the helical track 10 because the erasing heads 14 and 16 are wide. However, in splicing and assembling editing, the recording head 13 records the helical track 8 at a new point in time. After erasing the helical track 10 at the old time, the recording head 15 records the helical track 9 at the new time, and the erasing head 16 erases the helical track 11 at the old time. Are alternately and repeatedly executed.

The timing of the magnetic head at this time is as shown in FIG. First, when the recording head 13 scans the helical track 8, RecA becomes High, so that the recording head 13 records the helical track 8, and then, when the recording head 15 scans the helical track 9, RecB becomes higher. High
Therefore, the recording head 15 is
Record Further, since the FEA and FEB become High or Low while synchronizing with each of these RecA and RecB, each of the erasing heads 14 and 16 erases the helical tracks 10 and 11 located at positions ahead of two tracks. .

That is, although the erasing timing here is the same as the recording timing, the erasing heads 14 and 16
Is located at a position two tracks ahead of the recording heads 13 and 15, the erasing operation is also performed from a position two tracks ahead, and as a result, the effect of the erasing operation is affected by the helical track. 7 would have been excluded. At the time of insert editing, only the range to be inserted is deleted.

[0026]

As described above, in the magnetic recording / reproducing apparatus according to the present invention, the configuration in which the erasing head erases the area above the helical track where the recording head ends the recording, or the recording head ends the recording. A configuration is employed in which an area above the helical track is erased, and the erasing head starts erasing from a position preceding the helical track where the recording head starts recording. Therefore, according to the present invention, the helical track at the splicing position under the narrow track and the helical track at the assemble editing position can be a helical track of the same quality as the helical track in the normal recording range. An effect that a high-quality signal can be easily obtained even in shooting or assembling editing is ensured.

[Brief description of the drawings]

FIG. 1 is a plan view schematically illustrating the structure of a head drum included in a magnetic recording / reproducing apparatus according to the present embodiment and a conventional embodiment.

FIG. 2 is a block diagram showing a circuit configuration of a head drum according to the embodiment.

FIG. 3 is an explanatory diagram showing a magnetic tape pattern at the end of recording according to the embodiment.

FIG. 4 is an explanatory diagram showing a positional relationship between a magnetic tape pattern and a magnetic head at the end of recording according to the embodiment.

FIG. 5 is an explanatory diagram showing the timing of the magnetic head at the end of the recording operation according to the embodiment.

FIG. 6 is an explanatory diagram showing a positional relationship between a magnetic tape pattern and a magnetic head at the start of recording according to the embodiment.

FIG. 7 is an explanatory diagram showing timing of a magnetic head at the start of a recording operation according to the embodiment.

FIG. 8 is an explanatory diagram showing a magnetic tape pattern at the end of recording according to a conventional embodiment.

FIG. 9 is an explanatory diagram showing a positional relationship between a magnetic tape pattern and a magnetic head at the end of recording according to a conventional embodiment.

FIG. 10 is an explanatory diagram showing timing of a magnetic head at the end of a recording operation according to a conventional embodiment.

FIG. 11 is an explanatory diagram showing a positional relationship between a magnetic tape pattern and a magnetic head at the start of recording according to a conventional embodiment.

FIG. 12 is an explanatory diagram showing timing of a magnetic head at the start of a recording operation according to a conventional embodiment.

FIG. 13 is an explanatory diagram showing a positional relationship between a magnetic tape pattern and a magnetic head at the start of recording according to a conventional embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic tape 2-12 ... Helical track 13, 15 ... Recording head 14, 16 ... Erase head 17 ... Head drum 26 ... Recording circuit 27 ... Erase circuit 28 ... Control circuit

Claims (2)

[Claims] 1. A head drum comprising: a recording head for recording a helical track on a magnetic tape; an erasing head for erasing the helical track at a position preceding the recording head; and a recording signal to the recording head. A recording circuit that outputs an erasing signal to the erasing head, and a control circuit that controls the erasing circuit and the recording circuit, wherein the erasing head completes recording. A magnetic recording / reproducing apparatus characterized in that an area above a helical track is erased. 2. A head drum comprising: a recording head for recording a helical track on a magnetic tape; an erasing head for erasing the helical track at a position preceding the recording head; and a recording signal to the recording head. A recording circuit that outputs an erasing signal to the erasing head, and a control circuit that controls the erasing circuit and the recording circuit, wherein the erasing head completes recording. A magnetic recording / reproducing apparatus, wherein an area above a helical track is erased, and erasing is started from a position preceding the helical track where the recording head starts recording.