JPH0434708A - Rotary head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain proper reproducing at a speed twice that of read-after-write recording by selecting the width of a 2nd head covering a scanning track of a 1st head, selecting the running speed twice that of the read-after-write reproducing, and reading a written signal every time the 1st and 2nd heads scan a tape. CONSTITUTION:The width of a 2nd read magnetic head Rb is selected wider so as to bridge itself over a track scanned by a 1st read head Ra. At recording, a track with a signal written by 1st and 2nd write magnetic heads Wa, Wb is properly read by 1st and 2nd read magnetic heads Ra, Rb corresponding to the track, and the write magnetic head Wa applies excellent consecutive recording based on a control signal read from a track by the 1st read magnetic head Ra at the changeover from the reproduction to the recording. Since the width of the 2nd read magnetic head Rb is set wide, both the 1st and 2nd read magnetic heads Ra, Rb scan their relevant tracks properly at operating speed in the reproducing twice that in the recording.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a rotary head type recording/reproducing device.

A digital audio tape recorder (Digital Audio Tape Recorder) is an example of a conventional rotary head type recording/playback device.

Tape recorder (hereinafter abbreviated as DAT) is well known. This DAT has a magnetic head installed on the circumferential surface of a rotating drum that is driven to rotate in contact with a running magnetic tape, and uses this magnetic head to scan in a direction across the magnetic tape to write digital signals onto the magnetic tape, or to write digital signals onto the magnetic tape. It is designed to read digital signals recorded on.

In such a rotating head type recording/reproducing device,
Data signals are recorded alternately by two write magnetic heads Wl and W2 that scan the tracks of the magnetic tape, and each write magnetic head is rotated every time each write magnetic head Wl and W2 records a data signal. The two read magnetic heads R1 and R2, which are respectively associated with the head WIW2 and scan the tracks immediately after being recorded by the respective write magnetic heads Wl and W2, read the recorded signals to check whether the recording is being performed correctly. There is also a well-known device equipped with a read-after-write recording function that checks whether or not the data is written.

FIG. 12 shows each magnetic head Wl on the rotating drum 1 of a conventional DAT having the read-after-write recording function.
, W2. The arrangement of R1 and R2 and the winding of the magnetic tape T around the rotating drum 1 are diagrams showing the angle α, etc.

Each of the four magnetic heads Wl, W2 . R1 and R2 are arranged on the circumferential surface of the rotating drum 1 with an installation angle of 90'' between them.In other words, the two writing magnetic heads Wl
, W2 are two mutually orthogonal diameter lines D of the rotating drum 1
The two magnetic heads R1 and R2 are provided so as to be located on the remaining diameter line D2. Further, if the rotating drum 1 is rotationally driven to the left, the reading magnetic head R associated with the writing magnetic head W1
1 is arranged at a position rotated in the circumferential direction to the right from the write magnetic head W1, and the read magnetic head R2 corresponding to the write magnetic head W2 is also arranged in the circumferential direction to the right from the write magnetic head W2. placed in a rotated position. Furthermore, the angle α of the winding of the magnetic tape T around the rotating drum 1 is set to 90°.

FIG. 13 is a timing chart showing the read-after-write recording operation in the DAT, of which the first
Figure 3 (1) shows the operation timing of the write magnetic head W1゜■r2, and Figure 13 (2) shows the operation timing of the read magnetic head R.
1 and R2 are shown.

In this case, when the write magnetic head W1 scans the magnetic tape T and writes data while the rotating drum 1 rotates 1/4, the same track on the magnetic tape T is read in the next 1/4 rotation. The magnetic head R1 scans and reads recorded data,
Furthermore, in the next 1/4 rotation, the other write magnetic head W2 scans the magnetic head 7T and writes data to the track adjacent to the above track, and in the following 1/4 rotation, the same track is used for reading the other track. The magnetic head R2 scans and reads recorded data, and this operation cycle is repeated every rotation of the rotary drum 1.

During reproduction, by operating only the reading magnetic rads R1 and R2 at the operation timing shown in FIG. 13(2),
Recorded data is read at the same speed as when it was recorded.

By the way, in order to meet the demand for miniaturization of DAT, each magnetic head in the rotating drum 1 is
When trying to reduce the diameter of the rotating drum 1 without changing the arrangement of R2 or the winding length of the magnetic tape T wound around the circumferential surface of the rotating drum 1, that is, the track length scanned by each magnetic head, When winding the magnetic tape T around the rotating drum 1, the angle α must be larger than 90°.

FIG. 14 is a timing chart showing the read-after-write recording operation in this case, of which FIG.
) shows the operation timing of the write magnetic heads Wl, W2, and FIG. 14(2) shows the operation timing of the read magnetic heads R1, R2.

In this case, the second half of the operation in which the write magnetic head W1 scans the magnetic tape T and writes data overlaps with the first half of the operation in which the read magnetic head R1 scans the same track and reads data, The second half of the recording data read operation by the read magnetic head R1 overlaps with the first half of the operation in which the next write magnetic head W2 scans the magnetic tape T and writes data to a track adjacent to the above track. However, the second half of the write operation by the write magnetic head W2 overlaps with the first half of the operation in which the other read magnetic head R2 scans the same track and reads recorded data, and The second half of the read operation of R2 overlaps with the first half of the write operation of the write magnetic head W1.

As a result, the write magnetic head w1. Crosstalk will occur between the signal to be recorded applied to w2 and the signal read from the magnetic tape T by the reading magnetic head R1°R2.

Therefore, as a measure to avoid crosstalk while maintaining the above configuration, the rotation speed of the rotary drum 1 is increased to, for example, twice the previous speed, and while the rotary drum 1 rotates once, the write magnetic heads Wl and W2 write. Perform only the action and move on to the next step.
A method has been proposed in which read-after-write recording is performed by performing only a read operation using the read magnetic heads R1 and R2 during rotation.

FIG. 15 is a timing chart showing the above-mentioned read-after-write recording operation, of which FIG. 15 (1) shows the write magnetic head W1. The operation timing of W2 is shown, and FIG. 15 (2) shows the operation timing of the reading magnetic heads R1 and R2.

In this case, while the rotary drum 1 rotates once, the write magnetic head W1. W2 each alternately scans one track of the magnetic tape T to write data, and during this time, the reading magnetic heads R1 and R2, which each alternately scan one track of the magnetic tape T, read the recorded data. On the other hand, in the next rotation, the write magnetic head Wl.

The corresponding read magnetic heads R1 and R2 scan the track scanned by W2 and read one track of recorded data alternately, while the write magnetic heads Wl and W2 perform a write operation. Blocks indicated by broken lines in FIG. 15 that do not perform write or read operations while the write magnetic heads Wl, W2 and the read magnetic heads R1, R2 are actually scanning the magnetic tape T. It shows no timing. In this way, one cycle of recording operation is performed by two rotations of the rotary drum 1.

During the reproducing operation, only the reading operation by the reading magnetic heads R1 and R2 is performed in the above timing chart.

At this time, the write magnetic head wr1. The track that is several tracks from the track scanned by w2 is read by the corresponding read magnetic heads R1 and R2 from the playback operation using the tracking control signal read by the read magnetic heads R1 and R2 from the track. This is so that when switching to a recording operation, the write magnetic heads Wl, W2 connect a new track appropriately adjacent to the last recorded track on the magnetic tape T, that is, perform good splicing.

In this way, in order to enable the reading magnetic heads R1, R2 to read tracks several tracks apart from the tracks scanned by the writing magnetic heads Wl, W2, the writing magnetic heads Wi, W:2 Between the reading magnetic heads R1 and R2, a step is provided on the circumferential surface of the rotating drum in a direction parallel to the rotation axis of the rotating drum 1, and between the writing magnetic heads Wl and W2 and between the reading magnetic heads Wl and W2. Head R
A similar level difference is also provided between IR2.

FIG. 17 is a timing chart showing a read-after-write recording operation in a specific example of the DAT driving method shown in FIG. 15, and FIG. 18 is a timing chart showing a reproducing operation in the driving method.

FIG. 16 shows each magnetic head Wa, Wb, and Ra in the rotating drum 2 used in this driving method.

The arrangement of Rb and the winding of the magnetic tape T around this rotary drum 2 are diagrams showing angle α, etc. The diameter of this rotating drum 2 is set smaller than the diameter of the rotating drum 1 in a conventional DAT whose timing chart is shown in FIG. In addition, two write magnetic heads Wa, W
b The positions between each other are located on the ~diameter line dl of the rotating drum 2,
That is, they are arranged at an angle of 180° in the circumferential direction, and the reading magnetic heads Ra and Rb are also arranged at an angle of 180° in the circumferential direction. Further, assuming that the rotary drum 2 is rotationally driven counterclockwise, the first magnetic read head Ra associated with the first magnetic write head Wa is slightly smaller than the second magnetic write head wb. A second read magnetic head Rb, which is arranged to be shifted to the left side and corresponds to the second write magnetic head wb, is arranged slightly shifted to the left side from the first write magnetic head Wa. . That is, the first magnetic write head Wa and the second
A second magnetic head for writing wb and a first magnetic head for reading are arranged at approximately the same circumferential position as the magnetic reading head Rb, and a second magnetic head for writing wb and a first magnetic head for reading are arranged at a position separated by an angle of approximately 180 degrees in the circumferential direction from this position. Ra is arranged.

Further, the angle α of the winding of the magnetic tape T around the circumferential surface of the rotating drum 2 is set to a range of 90° or more and within 180''. A constant track length is ensured.Furthermore, here, the track that is one track behind the track scanned by the first magnetic write head Wa, that is, the track that was scanned by the first magnetic write head Wa one time before. The first read magnetic head Ra scans the track scanned by the second write magnetic head wb, and the track that is one track behind the track scanned by the second write magnetic head wb, that is, the track that was previously scanned by the second write magnetic head wb. Each of the write magnetic heads Wa, W is arranged so that the scanned track is scanned by the second read magnetic head Rb.
The magnetic heads Ra and Rb for magnetic heads b and i are arranged so as to be slightly shifted by 1 in the direction parallel to the rotation axis of the rotary drum 2.

In the read-after-write recording operation shown in FIG. 17 in this case, for example, the first write magnetic head Wa writes data to track A N-1 of the magnetic tape T by 1/2 rotation of the rotary drum 2. is performed, and in the next 1/2 rotation, the first read magnetic head Ra reads the track AN-2, that is, the track on which writing was previously performed by the first write magnetic head Wa. will be held. Next 1
/2 rotations to track BN-2, that is, track A N-
2, the second read magnetic head wb is applied to the track written by the second write magnetic head wb.
Further, in the next 1/2 rotation, the second write magnetic head wb writes to the track BN-1 following the track AN-1. This operation is repeated in the same manner, with two revolutions of the rotary drum 2 as one cycle.

On the other hand, in the reproducing operation shown in FIG. 18, each write magnetic head W a is adjusted by utilizing only the operation of the read magnetic heads Ra and Rb in FIG. 17.

The tracks written by wb are sequentially read by the corresponding reading magnetic heads Ra and Rb. In FIG. 18, the reading magnetic heads Ra and Rb, particularly when scanning the magnetic tape T but not performing a reading operation, are shown with diagonal lines. In FIG. 17, the magnetic head that scans the magnetic tape T without operating in this way is not shown.

Problems to be Solved by the Invention In the case of the DAT shown in FIGS. 16 to 18, apart from the read-after-write recording operation in which the writing magnetic heads Wa, Wb and the reading magnetic heads Ra, Rb are used together. Also, regarding the reproduction operation using only the reading magnetic heads Ra and Rb, even if the reading operation is performed every time the magnetic tape T is scanned, Talostalk will occur between the two reading magnetic heads Ra and Rb. Therefore, if the running speed of the magnetic tape T is doubled and the reading magnetic heads Ra and Rb, which are indicated by diagonal lines in FIG. 18, are also responsible for reading operations, it should be possible to double the playback speed. It is.

However, in order to properly connect the reading magnetic heads Ra and Rb during the read-after-write recording operation, the mounting position on the circumferential surface of the rotating drum 2 is determined by the rotation of the rotating drum 2 as described above. Because the step is provided in the direction parallel to the axis, even if the running speed of the magnetic tape T is doubled, each reading magnetic head Ra, Rb will not scan one track in turn alternately, and the 19th As shown in the timing chart in the figure, the tracks scanned by the two reading magnetic heads Ra and Rb and the tracks not scanned by any of the reading magnetic heads alternate, resulting in the playback speed being doubled. Can not do it.

However, if the two reading magnetic heads Ra and Rb are mounted on the two circumferential surfaces of the rotary drum without a step difference, the above-mentioned disadvantage can be overcome and the reproduction speed can be doubled. However, in this case, a new problem arises in that proper splicing cannot be performed in the read-after-write recording operation.

Therefore, an object of the present invention is to provide a rotary head type recording and reproducing apparatus that uses a small-diameter rotary drum, can perform good splicing during recording, and can perform proper reproducing operation at twice the speed of recording operation. The goal is to provide the following.

Means for Solving the Problems The present invention provides first and second write magnetic heads, and first and second read magnetic heads corresponding to the first and twentieth write magnetic heads, respectively. By running the magnetic tape wrapped at a predetermined angle around the circumferential surface of a rotating drum that is attached to a head and rotated at a constant speed, the first and second magnetic writing heads write the magnetic tape. scanning to write a signal on the magnetic tape, scanning the tracks on the magnetic tape with the first and second magnetic reading heads to read the write signal, and writing one track with the first magnetic writing head. After one track of writing is performed by the second magnetic write head, the first magnetic read head is applied to the track written by the first magnetic write head. After one track of writing is performed by the second write magnetic head and one track of writing is performed by the second write magnetic head, the second write magnetic head When a read-after-write recording operation is performed in which a second reading magnetic head reads a track written by the head, and when switching from a reproduction operation to a recording operation, a read-after-write operation is performed in which a track written by the head is read. By controlling the scanning position of the write magnetic head with respect to the magnetic tape based on the signal,
Each magnetic head is mounted on a rotating drum in a rotating head type recording/reproducing device whose position is determined so that a new track on which a signal is written on the magnetic tape is properly connected to a track on which a signal has previously been written. The second magnetic read head is wide enough to span the track scanned by the first magnetic read head, which is the previous track adjacent to the track scanned by the second magnetic head during read-after-write recording. setting to make the running speed of the magnetic tape twice as fast as in read-after-write recording operation during playback operation, and to read the write signal every time the first and second read magnetic heads scan the magnetic tape. This rotary head type recording and reproducing apparatus is characterized in that it is possible to appropriately perform a reproducing operation at twice the speed of a read-after-write recording operation.

According to the present invention, during a recording operation, tracks on which signals are written by the first and second write magnetic heads are properly read by the corresponding first and second read magnetic heads, and reproduction is performed. In switching from operation to recording operation, the mounting established between the magnetic write head and the magnetic read head on the rotating drum is such that the first magnetic read head writes based on the control signals read from the track. Good splicing is achieved by the embedded magnetic head.

In addition, during a playback operation, the width of the second read magnetic head that scans a subsequent track adjacent to the track is set wide so that it protrudes into the track that the first read magnetic head scans during a recording operation. Therefore, both the first and second reading magnetic heads can properly scan the corresponding tracks at twice the operating speed during recording.

Embodiment FIG. 1 is a block diagram showing the configuration of a system in which a DAT 3, which is an embodiment of the rotary head type recording/reproducing apparatus of the present invention, is used as an auxiliary storage device of an external computer 4.

The interface 5 is a circuit for exchanging data such as image information, audio information, and arithmetic processing information with the external computer 4.
Data is exchanged in units of information for each track, ie, each frame.

FIG. 2 is a diagram schematically showing the format of one frame of data described above. That is, one frame includes, for example, five data areas a to e, and these data areas a to e.
The parity areas Pa to Pe individually correspond to the parity areas Pa to Pe.

The memory 6 is for temporarily storing data provided to the interface 5. The signal processing circuit 7 is a circuit for processing the data to be recorded provided from the interface 5 into a signal suitable for recording on the magnetic tape T.

The rotating drum 8 has two write magnetic heads Wa and Wb that scan the magnetic tape T and write data on its circumferential surface, and two read magnetic heads that scan the magnetic tape T and read recorded data. The head Ra and Rb are arranged,
The signal processed by the signal processing circuit 7 is amplified by an amplifier 9 and selectively input to the write magnetic heads Wa, Wb.

The amplifier 10 is a circuit that selectively takes in and amplifies the signals read by the reading magnetic heads Ra and Rb.
The amplified signal is sent to the signal processing circuit 1 via the synchronous gate ill.
2 is input. This signal processing circuit 12 is a circuit for converting the captured signal into a signal before being recorded on the magnetic tape T, and the converted signal is inputted to the interface 5. , the signal processing circuits 7 and 12, the servo circuit 14, and other circuits for controlling the overall operation of the DAT 3. The servo circuit 14 is a circuit for controlling the driving of a motor 15 that rotationally drives the rotary drum 8, a capstan motor that runs the magnetic tape T, and the like.

The synchronization circuit 16 includes a signal processing circuit 7.12, an amplifier 9,
This is a circuit for synchronizing the operation timing of 10.
The clock generation circuit 17 is a circuit that generates a clock signal for the synchronous control operation of the synchronous circuit 11.

FIG. 3 shows the writing magnetic heads Wa, Wb and the reading magnetic head Ra provided on the circumferential surface of the above-mentioned rotating drum 8.
4 is a plan view showing the arrangement of Rb, and FIG. 4 is a perspective view showing a state in which the magnetic tape T is wound around the circumferential surface of the rotating drum 8. FIG. The diameter of the rotating drum 8 is set smaller than the conventional diameter of 30 mm, which is the diameter of the rotating drum in the DAT shown in the timing chart of FIG. In addition, two write magnetic heads Wawb'l
They are arranged at positions lined up on the -M diameter line di of the rotating drum 8, that is, separated by an angle of 18° in the circumferential direction! Also, an angle K18 is formed in the circumferential direction between the reading magnetic heads Ra and Rb.
They are spaced apart by 0'. Furthermore, the rotating drum 8
is rotated counterclockwise, and the first read magnetic head R associated with the first write magnetic head Wa is rotated counterclockwise.
a is arranged slightly to the left of the second write magnetic head wb, and the second read magnetic head Rb, which is associated with the second write magnetic head wb, is arranged slightly to the left of the second write magnetic head wb. The magnetic head Wa is arranged slightly shifted to the left. That is, the first write magnetic head Wa and the second read magnetic head Rb are arranged at approximately the same circumferential position, and the second magnetic head Wa and the second read magnetic head Rb are arranged at approximately the same circumferential position.
a writing magnetic head wb and a first reading magnetic head Ra.
and are arranged.

The winding angle α of the magnetic tape T wound around the circumferential surface of the rotating drum 8 is set in a range of 90" or more and 180" or less, and is associated with each of the writing magnetic heads Wa, Wb. Since the reading magnetic heads Ra and Rb are arranged at an angle of 180° in the circumferential direction, it is possible to secure the same track length as when using a rotating drum with a diameter of 30 mm, and also to avoid occurrence of tarostoke.

Furthermore, here, a track that is one track behind the track scanned by the first magnetic write head Wa, that is, a track scanned by the first magnetic write head Wa one time before, is scanned by the first magnetic head Wa for reading. Ra scans a track that is one track behind the track scanned by the second write magnetic head wb, that is, the track that was previously scanned by the second write magnetic head wb. In order to scan with the head Rb, the positions of the writing magnetic heads Wa, Wb and the reading magnetic heads Ra, Rb in the direction parallel to the rotation axis of the rotary drum 5 are as shown in FIG. are set slightly different from each other.

Further, the width dimension of the second reading magnetic head Rb is determined by the width of the second reading magnetic head Rb in the read-after-write recording operation.
It is set so that the track one before the track scanned by b, that is, the first magnetic reading head Ra protrudes most of the track scanned.

Next, an outline of the recording and reproducing operation by the DAT will be explained.

When recording data from the external computer 4 onto the magnetic tape T, the data from the external computer 4 is provided to the interface 5. The data is transmitted in units of information for two tracks on the magnetic tape T, that is, in units of one frame. One frame includes, for example, 5120 bytes of data, and is divided into frames by the external computer 4 and output.

At the interface 5, an error correction code is added to the parity areas Pa to Pe shown in FIG. 2 of the sent one frame of data. The data to which the error correction code has been added by the interface 5 is stored in the memory 6 and is also provided to the signal processing area B7. In the memory 6, as shown in FIG. 5, data for one frame is sequentially stored in each of eight divided storage areas MO to M7. in particular,
Data for one frame from the interface 5 is first stored in the storage area MO. At this time, the data in the storage area MO-M6 of the memory 6 is sequentially transferred to the right storage areas M1 to M7.
are shifted respectively. Furthermore, data in the storage area M7 is normally erased. For example, as shown in FIG. 5(a), when data with frame numbers N+7 to N are stored in storage areas MO to M7, respectively, frame number N
When data +8 and N+9 are sequentially input, the memory 6 changes to the storage state shown in FIG. 5<b>-FIG. 5(c). Input/output operations at the interface 5 are performed according to control signals from the control circuit 13.

The data given from the interface 5 to the signal processing circuit 7 is given an error correction code therein as in a normal rotary head type DAT, and then given to the amplifier 9. The data signal amplified by the amplifier 9 is sent to the first
writing magnetic head Wa and a second writing magnetic head wb.
The signal is selectively switched and applied to the magnetic tape T and written on the magnetic tape T.

The switching in the amplifier 9 is controlled by a signal synchronized with the rotation of the rotary drum 8 from a synchronization circuit 16.

The rotating drum 8 is rotated around the axis by the motor 15.
It is rotationally driven in the left direction as indicated by arrow P in the figure. The rotation speed of the motor 15 at this time is controlled by a surf circuit 4 that receives a control signal from the control circuit 13. Further, the magnetic tape T is run in the direction indicated by an arrow Q in FIG. 4 by a capstan motor (not shown) or the like.

By the above operation, the write magnetic heads Wa, Wb scan the magnetic tape T in an oblique direction as shown in FIG. 6, and tracks 1, 2, and 3 are sequentially formed.

The above-mentioned frame number is recorded in a part of the sub-coat areas 20a and 20b of each track A and B.

The data recorded on the magnetic tape T in this manner is read by the reading magnetic heads Ra, Rb, which correspond individually to the writing magnetic heads Wa, Wb. That is, the recorded data of track A written by the first magnetic write head Wa is read by the first magnetic read head Rat'', and the recorded data of track B written by the second magnetic write head wb is read by the first magnetic read head Rat''. The data is read by the second magnetic read head Rb.The data signals read by the read magnetic heads Ra and Rb are provided to the amplifier 10, respectively.

The data signal amplified by the amplifier 10 is sent to the synchronous circuit B1.
1, and synchronization with the clock signal from the clock generation circuit 17 is established here. Note that in the amplifier 10,
The outputs of the reading magnetic heads Ra and Rb are selectively switched and output according to a synchronization signal from the synchronization circuit 11.

The output of the synchronization circuit 11 is given to a signal circuit 12, where data error correction processing is performed. This error correction is performed based on the error correction code added by the signal processing circuit 7. At this time, signal processing such as error correction is performed by the synchronization circuit 16 synchronously with signal processing such as addition of an error correction code in the signal processing circuit 7.

Data output from the signal processing circuit 12 is given to the interface 5. Normally, the interface 5 performs an operation of temporarily storing the sent data in the memory 6, and then reading the data from the memory 6 and sending it to the external computer 4.

Next, details of the recording and reproducing operations of the DAT according to this embodiment will be explained with reference to timing charts shown in FIGS. 7 to 11.

In this case, the recording operation is performed using the first write magnetic field Wa.
Each time writing is performed, the same track is scanned by the first magnetic reading head Ra to read the recorded signal, and each time writing is performed by the second magnetic writing head wb, the same track is scanned by a second reading. This is a read-after-write recording operation in which the operation of scanning and reading recording signals with the magnetic head Rb is repeated.

FIG. 7 shows each magnetic head WaWb and Ra during the above recording operation.
, Rb is a timing chart showing the operation timing of Rb.

Each magnetic head Wa, Wb on the circumferential surface of the rotating drum 8.

Since the mounting positions of Ra and Rb are in the relationship shown in FIG. 3, in the recording operation shown in FIG. Wa and the second read magnetic head b scan, and at this time, the first write magnetic head Wa performs a write operation. That is, the recorded signal read by the second reading magnetic head Rb is transmitted to the amplifier 10 in FIG.
is not taken into account. In the next 1/2 rotation, the second magnetic write head wb and the first magnetic read head Ra scan the magnetic tape T, but at this time, the first magnetic read head Ra performs a read operation. only is done. In other words,
From the amplifier 9 in FIG.
No data signal is given to b. In the next 1/2 rotation, the first magnetic write head Wa and the second magnetic read head Rb again scan the magnetic tape T, but at this time only the read operation by the second magnetic head Rb is performed. It will be done. Furthermore, in the next 1/2 rotation, the second write magnetic head wb and the first read magnetic head a scan the magnetic tape T again, but at this time, the second write magnetic head wb writes. Only the action takes place. That is, one cycle of the read-after-write recording operation is performed by two rotations of the rotary drum 8.

FIG. 9 shows the pattern of each track on the magnetic tape T in the above recording operation and the magnetic nodes Wa, Wb that scan these tracks to perform a write operation and a read operation.
, Ra, and Rb, and the vertical axis t indicates time.

In this case, for example, track A with track number N-1
When the first write magnetic head Wa writes to N-1, the first read magnetic head Ra next writes to N-1. , that is, track A N-2 with track number N2.

Next, the second read magnetic head Rb reads the track B N-2 of track number N-2, which has already been written by the second write magnetic head wb.

Next, the second write magnetic head wb writes to the track B N-1 next to the track A N-1.

This operation period corresponds to two revolutions of the rotating drum 8 shown in FIG. 7, and the same operation is repeated thereafter.

For example, track A is written by the first magnetic write head Wa.
After writing is performed on track A N-1, the same first magnetic write head Wa writes to track A N-2, which was written one time before, is read by the first magnetic read head Ra. are the first write magnetic head W a and the first
This is because the mounting of the reading magnetic head Ra on the circumferential surface of the rotary drum 8 is provided with a step in the direction parallel to the rotation axis of the rotary drum 8, as described above.

When the reproduction operation is switched to the read-after-write recording operation, the first read magnetic head Ra changes the track of the first write magnetic head Wa based on a tracking control signal read from, for example, track A N-2. Control is performed to form a new track A N-1 properly adjacent to the recorded track B N-2. In other words, the connection is properly performed.

As mentioned above, the width of the second magnetic head Rb for reading is set large, and the track to be scanned by the magnetic head Rb, for example, the subsequent track A N-2 adjacent to the track B N-2. Since scanning is performed over the entire range, it is not preferable to use the tracking control signal read by the reading magnetic head wb as a linking control signal, and it is not used here.

FIG. 8 shows each reading magnetic head Ra, Rb during a reproducing operation.
3 is a timing chart showing the operation timing of FIG.

In this case, the running speed of the magnetic tape T is set to twice that of the recording operation. In the reproducing operation, the write magnetic head Wa,
Since no write operation is performed using Wb, the rotating drum 8
Every one or two rotations, the reading magnetic head scans the magnetic tape T in the order of Ra - + Rb - + Ra → Rb, as shown in FIG. 8, and a reading operation is performed each time.

FIG. 10 shows the pattern of each track on the magnetic tape T in a reproducing operation in which the traveling speed of the magnetic tape T is twice that of the recording operation, and each reading magnetic head Ra that scans the tracks to perform a reading operation. , Pj 'b, and FIG. 11 is a timing chart showing the relationship between the track pattern and each reading magnetic head Ra, Rb in a reproducing operation performed with the running speed of the magnetic tape T being the same as that in the recording operation. This is a timing chart showing the relationship, and the vertical axis t indicates time in each case.

In a reproducing operation when the running speed of the magnetic tape T is the same as that in the read-after-write recording operation, one track is scanned by two reading magnetic heads Ra and Rb, so as shown in FIG. When the reading magnetic heads Ra and Rb shown in FIG. 1 scan, the reading operation by the magnetic heads is omitted. As a result, the track AN-2 written by the first write magnetic head Wa,
AN-IAN, . . . is the first reading magnetic head Ra
and the tracks BN-2, BN-1, BN, which were written by the second magnetic write head wb.
... are each read once by the second reading magnetic head Rb.

On the other hand, in the reproducing operation when the running speed of the magnetic tape T is twice that of the read-after-write recording operation, as shown in FIG.
Rb also does not omit the reading operation, and each track is read by each corresponding reading magnetic head Ra, Rb.
The reading is performed once at a time. In other words, in a conventional DAT, if you try to perform a playback operation at twice the magnetic tape running speed as in a read-after-write recording operation, the first
As shown in Figure 9, one track is scanned by two magnetic read heads Ra and Rb, while the next track is not scanned by any of the magnetic read heads, which is a repeated operation. Therefore, in this embodiment, the width dimension is not set large and the second reading magnetic head Rb scans the track BN which was not scanned in the conventional example.
-2, BN-1, BN, . . . and can be responsible for reading these tracks.

Effects of the Invention As described above, according to the rotary head type recording/reproducing device of the present invention, during a recording operation, the tracks on which signals are written by the first and second write magnetic heads are moved to the corresponding first and second magnetic heads. The track control of the write magnetic head is performed based on the control signal read from the track by the first read magnetic head when switching from the reproduction operation to the recording operation. , the magnetic write head and the magnetic read head are mounted on the rotating drum in such a way that the positions of the magnetic write head and the magnetic read head are determined, and the subsequent tracks adjacent to the track are arranged so that the first magnetic read head protrudes to the side of the track scanned during the recording operation. Since the width of the second reading magnetic head that scans is set to be wide, it is possible to perform a good transition when switching from a reproduction operation to a recording operation, and the reproduction operation can be performed at twice the operating speed of the recording operation. be able to.

[Brief explanation of drawings]

Section 1 is a block diagram showing a schematic configuration of a rotary head type recording and reproducing device which is an embodiment of the present invention, and FIG. 2 shows the format of one frame of data handled by the rotary head type recording and reproducing device. 3 is a diagram showing the arrangement of each magnetic head on the rotating drum of the rotary head type E recording/reproducing device, and FIG. 4 is a perspective view showing the combined arrangement of the rotating drum and the magnetic tape wound around it. , 5th
The figure shows the order in which data is stored in the memory of the rotary head type recording/reproducing device, FIG. 6 shows the track pattern written on the magnetic tape by the rotary head type recording/reproducing device, and FIG. FIG. 8 is a timing chart showing the operation timing of each magnetic head during a recording operation by the rotary head type recording and reproducing device; FIG. Section 9 is a timing chart showing the relationship between the track pattern during recording operation by the rotary head type recording/reproducing device and each magnetic head, and Fig. 10 is a timing chart showing the track pattern during double speed reproducing operation by the rotary head type recording/reproducing device. FIG. 11 is a timing chart showing the relationship between the magnetic heads and the track pattern during constant speed playback operation by the rotary head type recording/reproducing device;
FIG. 12 is a diagram showing the arrangement of the magnetic head on the rotating drum of a conventional rotary head type recording/reproducing device.
N is a timing chart showing the recording and reproducing operation by the rotary head type recording and reproducing device, and FIG. 14 is a timing chart showing the conventional rotation.
A timing chart showing the recording and reproducing operation when the diameter of the rotating drum is reduced in a throat type recording and reproducing device. Fig. 15 shows a conventional rotary head type recording and reproducing device in which the diameter of the rotary drum is reduced and the number of revolutions is doubled. FIG. 16 is a timing chart showing the recording and reproducing operation of the device. FIG. 16 is a diagram showing the arrangement of each magnetic head on the rotating drum of the rotary head type recording and reproducing device. FIG. 17 is a timing chart showing the recording operation of the rotary head type recording and reproducing device. Timing chart showing the relationship between the track pattern and each magnetic head, 1st
Figure 8 is a timing chart showing the relationship between the track pattern and each magnetic head during playback operation by the rotary head type recording/reproducing device, and Figure 19 is a timing chart showing the relationship between the track pattern and each magnetic head during the reproducing operation by the rotary head type recording/reproducing device. 3 is a timing chart showing the relationship between a track pattern and each magnetic head when a reproduction operation is attempted. 3. DAT, 5... Interface, 6... Memory, 7.12... Signal processing circuit, 8... Rotating head, 9°10... Amplifier, 11.16... Synchronous circuit, 1
3 Control circuit, 14...Servo circuit, 15...Motor, 16 Clock generation circuit, Wa, Wb...Magnetic head for writing, Ra, Rb...Magnetic head for reading, T...
Magnetic tape agent Patent attorney Number of strokes Keiichi Katsurazu Figure 10 Drum rotation angle Figure R2 (1) Book υ Argument - Ronei [] Mouth 4] (2) Round cut [100 [ ] Engineering No. 131L! (1) 1st official year [Kuro-kite] 2[] Fig. 11 Fig. 14 (1) Calligraphy Kano-be] ni IF E22]

Claims (1)

[Scope of Claims] First and second magnetic writing heads and first and second magnetic reading heads corresponding to the first and second magnetic writing heads are attached, By running a magnetic tape wrapped at a predetermined angle around the circumference of a rotating drum that is rotated at a constant speed,
The first and second magnetic write heads scan the magnetic tape to write signals onto the magnetic tape, and the first and second magnetic read heads scan tracks on the magnetic tape to read the written signals. , After one track's worth of writing is performed by the first writing magnetic head and subsequent one track's worth of writing is performed by the second writing magnetic head, writing is performed by the first writing magnetic head. The first magnetic read head performs reading on the track where the above was performed, the second magnetic write head writes one track, and the second magnetic write head then writes one track. After writing is performed, a read-after-write recording operation in which a second reading magnetic head reads the track written by the second writing magnetic head can be performed, and the recording is performed from the playback operation. When switching to operation, the scanning position of the write magnetic head with respect to the magnetic tape is controlled based on the reproduction signal read by the first read magnetic head.
In a rotary head type recording/reproducing device, the mounting position of each magnetic head on a rotating drum is determined so that a new track on which a signal is written on the magnetic tape is properly connected to a track on which a signal has been previously written. The second reading magnetic head is set to have a wide width so as to span the previous track adjacent to the track scanned by itself and the track scanned by the first reading magnetic head during a read-after-write recording operation. By making the running speed of the magnetic tape twice as fast as in the read-after-write operation during the playback operation, and reading the write signal every time the first and second read magnetic heads scan the magnetic tape. A rotary head type recording and reproducing apparatus, characterized in that a reproducing operation can be properly performed at twice the speed of a read-after-write recording operation.