JPH01290168A - Recording and reproducing system for revolving drum head magnetic tape - Google Patents

Abstract

PURPOSE:To attain normal reverse revolution reproducing operation by executing recording and reproducing to a magnetic tape with using a revolving drum to fit a magnetic head which has two difference azimuth angles with an interval in a circumference direction. CONSTITUTION:One track is formed on a magnetic tape 1 by a magnetic head 3a, which has one azimuth angle, and the other track is formed with being alternatively adjacent to the above-mentioned track by a magnetic head 3b which has the other azimuth angle. At the time of regular revolution reproducing, the data of one track and the other track are led out in this order out of the plural tracks of the same contents. At the time of the reverse revolution reproducing, the contents of one track to be formerly read in the plural frames of the same contents and the contents of the other track to be lately read are led out according to this order. Thus, the data in the frame can be correctly led out even at the time of the reverse revolution reproducing in the same order as the time of the regular revolution reproducing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary drum head magnetic tape suitable for use in a recording and reproducing device called a rotary head digital audio tape (R-DAT). Concerning recording and playback methods.

2. Description of the Related Art Apparatuses for recording/reproducing audio signals converted into digital signals, digital data, etc. onto magnetic tapes have been put to practical use. In such a device, in order to increase the amount of data recorded on a magnetic tape, magnetic heads with different azimuth angles are installed on a rotating drum, and the magnetic tape is recorded by scanning the magnetic tape while rotating the rotating drum. /
Perform playback.

FIG. 6 is a diagram showing a track pattern of the magnetic tape 21 on which data has been written by such a method. Track A i (1=O+ 1 + 2,...

Track n) is composed of data written by a magnetic head having a positive azimuth angle, for example, and track Bi is composed of data written by a magnetic head having a negative azimuth angle, for example.

When normal rotation reproduction is performed, the rotating drum is driven to rotate in the direction of arrow 27 on the magnetic tape 21 running in the direction of arrow 25. A magnetic head with a positive azimuth angle and a magnetic head with a negative azimuth angle alternately scan tracks Ai and Bi and read data written on tracks Ai and Bi, thus reading data written on the magnetic tape 21. The data of tracks AO, BO, Al, B1. =-, An
.

The data in B rl is played back in this order. Such a reproduced signal is derived as shown in FIG. 7(2).

Normally, one set of tracks Ai and Bi constitutes one frame Fi, and so-called interleaving, which rearranges the order of data when recording data on the magnetic tape 21, is completed within this one frame.

For this purpose, the reproduced data is processed in units of one frame.

In the processing circuit that processes the reproduced data, based on the track identification signal obtained by detecting the rotation of the rotating drum,
Identify the two tracks that make up the frame. As shown in FIG. 7(1), this track identification signal is at a low level during a period including, for example, the reproduction period of the track Ai, and is at a high level during a period including the reproduction period of the track Bi.

The processing circuit processes the reproduced signal derived during the period when the track identification signal is at a low level and during the period when the track identification signal is at a high level following the period when the track identification signal is at a low level, as one frame of data.

In this manner, the magnetic tape reproducing apparatus can correctly process the data of tracks Ai and Bi that constitute one frame Fi.

Problems to be Solved by the Invention In the magnetic tape playback device described above, when the magnetic tape is run in the direction shown by the arrow 26 and reverse playback is performed, the signal derived from the magnetic head is as shown in FIG. ) is shown. The track identification signal at this time is shown in Figure 8 (
As shown in 1). The processing circuit that processes the playback signal recognizes the playback signal derived during the period when the track identification signal is low level and the period when the track identification signal is high level following this low level period as one frame, so reverse playback is performed. In this case, it is erroneously recognized that track Ai+1 and track Bi constitute one frame. Therefore, with such a device, normal reverse playback operation cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotating drum head magnetic tape recording and reproducing system that solves the above technical problems and can perform normal reverse reproducing operation with a simple configuration.

SUMMARY OF THE INVENTION The present invention provides a method for recording a magnetic tape to be read using a rotating drum having one or more circumferentially spaced magnetic heads each having two different azimuth angles. One track is formed by a magnetic head having an azimuth angle, the other track is formed alternately adjacent to the one track by a magnetic head having an azimuth angle, and the adjacent one track and the other track are formed by a magnetic head having an azimuth angle. constitutes one frame, and multiple pieces of the same frame of data are recorded adjacently, one track is read by one magnetic head, the other track is read by the other magnetic head, and forward rotation is performed. During playback, one track and the other track of a plurality of tracks with the same content are derived in this order, and during reverse playback, the first track read earlier and the track read subsequently in multiple frames with the same content are derived. This rotary drum head magnetic tape recording and reproducing system is characterized in that each content of the other track is derived in this order.

According to the present invention, recording and reproduction on a magnetic tape can be performed using a rotating drum to which one or more magnetic heads each having two different azimuth angles are attached at intervals in the circumferential direction. be exposed.

On this magnetic tape, one track is formed by a magnetic head having one azimuth angle, and the other track is formed alternately adjacent to the one track by a magnetic head having another azimuth angle.

One adjacent track and the other track constitute one frame, and only a plurality of adjacent frames having the same content are recorded, and in this magnetic tape, the content of one track is read by one magnetic head. The contents of the other track are read by the other magnetic head.

During forward playback, data of one track and the other track of a plurality of tracks having the same content are derived in this order. Also, during reverse playback, the content of the one track read earlier in multiple frames with the same content,
The contents of the other track read subsequently are derived in this order.

Therefore, data within a frame can be correctly derived during reverse playback in the same order as during normal playback.

Embodiment FIG. 1 is a block diagram showing the configuration of a magnetic tape recording/reproducing apparatus 20 for recording and reproducing magnetic tape called R-DAT according to an embodiment of the present invention. The magnetic tape recording/reproducing device 20 includes a rotating drum 2 and a changeover switch S.
It is configured to include Wa, SWb, a buffer circuit 5, a signal processing circuit 6, a 1M control circuit 7, and a data extraction circuit 14.

Magnetic heads 3a and 3b are provided on the side surface of the cylindrical rotating drum 2 at positions facing each other by 180 degrees.

The magnetic heads 3a and 3b are mounted with different azimuth angles to prevent noise due to crosstalk.

The magnetic tape 1 is wound around the side surface of the rotating drum 2 by about 90 degrees.

When recording data on the magnetic tape 1, this data is divided into data signals DAIN for each frame, which will be described later.
The signal is input to the signal processing circuit 6 as a signal. The signal processing circuit 6 adds parity, which is an error correction code, to the data signal DAIN in units of one frame based on a track identification signal H8W, which will be described later. Apply processing.

The output from the signal processing circuit 6 is input to the buffer circuit 5 and stored. Data of the same frame is sent from the buffer circuits twice and sent to the changeover switch SW.
It is output to a. The changeover switch S W a selectively conducts the terminal T3 and either the terminal T1 or the terminal T2 based on the track identification signal H3W, and switches the data from the buffer circuit 5 to the amplifiers 4a and 4b for output. . The output from amplifier 4a is given to magnetic herad 3a. Further, the output from the amplifier 4b is given to the magnetic head 3b. Data is written onto the magnetic tape 1 by the magnetic heads 3a and 3b.

When the magnetic heads 3a, 3b write data on the magnetic tape 1, the magnetic tape 1 is run in the direction of arrow 22, and the rotary drum 2 is driven to rotate in the direction of arrow 24. At this time, since the same frame of data is output twice from the magnetic heads 3a and 3b, the track pattern written on the magnetic tape 1 is as shown in FIG.

In FIG. 3, the track At(i=o, 1°2,...
, n) are composed of data written by the magnetic head 3a, and track Bi is composed of data written by the magnetic head 3b. A pair of trucks A
i and track Bi constitute one frame Fi'. The above-described data rearrangement by interleaving is completed within this frame F1, and signal processing in the signal processing circuit 6 is also performed using this frame Fi as a unit.

Therefore, data from tracks Ai and Bi are inputted to the signal processing circuit 6 in this order, and the signal processing circuit 6 detects that the tracks Ai and Bi are frame Fit! : It is necessary to recognize that it is configured.

When reading data from the magnetic tape 1 on which data has been written, the magnetic heads 3a, 3. The reproduced signals from the amplifiers 8a and 8b are respectively given to amplifiers 8a and 8b. Amplifier 8a, 8
The output of switch SWb is output from terminal T4. T5 respectively.

The switch SWb conducts the terminal T4 and the terminal T6 during the period when the magnetic head 3a is reproducing data on the magnetic tape 1 based on the track identification signal (SW) from the detection circuit 13, which will be described later. While the head 3b is reproducing data on the magnetic tape 1, the terminals T5 and T6 are
Conducts with. The signal output from the terminal T6 is given to the signal processing circuit 6, where the signal processing circuit 6 performs signal processing such as error correction by parity described above and deinterleaving to restore the rearrangement by interleaving described above. .

From the signal processing circuit 6, a data signal DAOUT is sent via a line 11, and a signal FSW is sent via a line 12.
The signal is applied to the data extraction circuit 14.

The data extraction circuit 14 extracts data according to the content described later and outputs it as a data signal EXOUT.

The signal processing operation in the signal processing circuit 6 is controlled by the control circuit 7. Also, this control circuit 7 is the servo circuit 1
A control signal is sent to 1. The detection circuit 13 outputs a track identification signal H3W based on a signal from the detection element 10 that detects the magnet 9 fixed to the rotating drum 2, and the servo circuit 11 is also provided with this track identification signal H3W.

The servo circuit 11 controls the motor 12 that rotates the rotary drum 2 based on these signals.

FIG. 2 is a block diagram showing the configuration of the data extraction circuit 14. The data extraction circuit 14 includes a delay circuit 15, an exclusive NOR gate 16, a flip-flop 17,
It is configured to include an OR circuit 18. The data extraction circuit 14 is supplied with a track identification signal H8W, a frame identification signal FSW, and a data signal DAOUT. The frame identification signal FSW is applied to one input of exclusive NOR gate 16 and is applied to the other input of exclusive NOR gate 16 via delay circuit 15 . The delay circuit 15 transmits the frame identification signal FSW for a period ΔT.
only to be delayed. The output from exclusive NOR gate 16 is
It is applied to the reset input terminal R of the flip-flop 17.

A track identification signal H3W is applied to the input terminal CK of the flip-flop 17. Further, the output terminal Q and the input terminal are connected, and the flip-flop 17 latches the signal input to the input terminal at the falling edge of the track identification signal (ISW) and outputs it from the output terminal Q as a signal SDA. . Therefore, the flip-flop 17 outputs a signal SDA which is at a low level at the rise and fall of the frame identification signal FSW and changes in level at the fall of the track identification signal HSW.

This signal SDA is applied to one input portion of the OR circuit 18. The data signal DAOUT is applied to the other input portion of the OR circuit 18, and the output from the OR circuit 18 is output as the data signal EXOUT.

FIG. 4 is a timing chart for explaining the operation of the magnetic tape recording/reproducing apparatus 20 during normal rotation reproduction.

The track identification signal H8W output from the detection circuit 13 is at a low level including the period when the magnetic head 3a is reproducing data on the magnetic tape 1, as shown in FIG. is at a high level including the period when the data on the magnetic tape 1 is being reproduced. The identification signal FSW is a signal obtained by dividing the frequency of the track identification signal H3W by four, as shown in FIG. 4(2).

The delay circuit 15 outputs a signal FSWI obtained by delaying the frame identification signal FSW by ΔT. Signal FSWI is the fourth
This is shown in Figure (3). A frame identification signal FSW and a signal FSWI are input to the exclusive NOR gate 16,
A reset signal R3T is output that becomes low level for a time ΔT from the rise and fall of the frame identification signal FSW.

The reset signal R3T is shown in FIG. 4 (4).

The reset input terminal R of the flip-flop 17 is low active, and when the reset signal RST is at a low level, the signal SDA output from the output terminal Q is at a low level. Therefore, as shown in FIG. 4(5), the level of the signal SDA changes at the fall of the track identification signal H3W, and becomes low level during the low level period of the reset signal R8T.

The data signal DAOUT and the signal SDA shown in FIG. 4(6) are input to the OR circuit 18. Therefore, this data extracting circuit 14 outputs data of tracks At and Bi constituting the same frame Fi in this order, as shown in FIG. 4(7).

FIG. 5 is a timing chart for explaining the operation of the magnetic tape recording/reproducing apparatus 20 during reverse playback.

The track identification signal H3W output from the detection circuit 13 is at a low level including the period when the magnetic head 3a is reproducing data on the magnetic tape 1, as shown in FIG. is at a high level including the period when the data on the magnetic tape 1 is being reproduced. Further, the identification signal FSW is a signal obtained by dividing the frequency of the track identification signal H3W by four, as shown in FIG. 5(2).

The delay circuit 15 outputs a signal FSWI obtained by delaying the frame identification signal FSW by ΔT. Signal FSWI is the fifth
This is shown in Figure (3). A frame identification signal FSW and a signal FSW1 are input to the exclusive NOR gate 16,
A reset signal R3T is output that becomes low level for a time ΔT from the rise and fall of the frame identification signal FSW.

The reset signal R3T is shown in FIG. 5(4).

The reset input terminal R of the flip-flop 17 is so-called low active, and outputs a signal SDA that becomes low level when the reset signal R3T is low level. Therefore, as shown in FIG. 5(5), the level of the signal SDA changes at the fall of the track identification signal H3W, and becomes low level during the low level period of the reset signal R3T.

The data signal DAOUT and the signal SDA shown in FIG. 5(6) are input to the OR circuit 18. Therefore, the data extraction circuit 14 outputs the data of the track At and the track Bi constituting the same frame Fi in this order, as shown in FIG. 5(7).

In this way, in this embodiment, normal reverse playback and
In other words, when the magnetic tape 1 is played back by running in the opposite direction to that during recording, the data of the same frame can be derived in the same order as during forward playback, and the magnetic tape recording/
The convenience of the playback device is improved.

In this embodiment, the R-DAT magnetic tape recording/playback device 20 has been described, but if it is a rotating drum head type recording/playback device, other magnetic tape recording/playback devices such as a video tape recording/playback device can be used. The invention can also be implemented in a device.

As described in detail, the present invention provides a rotating drum head type magnetic tape recording/playback device that can perform normal reverse playback operation simply by adding a simple configuration and is more convenient. It can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a rotating drum head type magnetic tape recording/reproducing apparatus 20 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing the configuration of the data extraction circuit 14 of the magnetic tape recording/reproducing device 220, and FIG.
FIG. 4 is a timing chart for explaining the operation of the magnetic tape recording/reproducing device 20 during forward playback, and FIG. 5 is a diagram showing the operation of the magnetic tape recording/playback device 20 during reverse playback. FIG. 6 is a diagram showing a track pattern of the magnetic tape 21 recorded by a conventional magnetic tape recording/reproducing device, and FIG. 7 is a timing chart for explaining the conventional magnetic tape recording/reproducing device. FIG. 8 is a timing chart for explaining the operation of a conventional magnetic tape recording/reproducing apparatus during reverse reproduction. 1... Magnetic tape, 2... Rotating drum, 3a, 3b
...-Magnetic head, 4a, 4b, 8a
, 8b...Amplifier 55...Buffer circuit, 6
... signal processing circuit, 7 ... control circuit, 9 ... magnet, 10 ... detection element, 11 ... servo circuit,
12... Motor, 13... Detection circuit, 14... Data extraction circuit, 15... Delay circuit, 16... Exclusive NOR gate, 17... Flip-flop, 18...
・Order circuit agent Patent attorney Kei Saikyo Part 6 g7 Figure I! 8 Figure

Claims (1)

[Claims] A rotating drum having one or more magnetic heads each having two different azimuth angles, spaced apart in the circumferential direction, is used to read a magnetic tape having one azimuth angle. One track is formed by a magnetic head, and the other track is formed by a magnetic head having an azimuth angle alternately adjacent to the one track, and the adjacent one track and the other track are 1
The data of the same frame is recorded adjacently, and one track is read by one magnetic head, and the other track is read by the other magnetic head. One track and the other track of the plurality of tracks of content are derived in this order, and during reverse playback, the first track read first and the other track read subsequently in the plurality of frames of the same content are derived. A rotary drum head magnetic tape recording and reproducing system characterized in that each content of the above is derived in this order.