JPH1166744A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent information signal in running reversion period of a tape from being omitted by intermittently storing unit information in the recording impossible period at the time of reversing the running direction of a magnetic tape and recording the information while reading them when a recording becomes recordable. SOLUTION: In a signal processing part 43 being in a tape running direction reversion period, when the running direction of a magnetic tape T is started, unit information signals of an input signal are intermittently stored in a memory 38 with a write signal of a timing oscillator 39 by changing over a changeover switch 40 with a changeover signal from the timing signal generator 39. When a recording impossible period is completed by the reversion of the tape running direction and the magnetic tape T becomes a returning path recording operation possible running state, a recording is performed by reading the unit information signals from the memory 38 with a read signal from the timing signal generator 39 and by supplying them to a recording and reproducing signal processing part 42. When the reading of the information signals from the memory 38 is completed, the returning path recording operation is performed by supplying the inputted information signals to the processing part 42 while changing over the switch 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a helical scan type magnetic recording / reproducing apparatus capable of performing a reciprocating recording / reproducing operation without substantially causing a signal loss during a reversal operation of a running direction of a magnetic tape.

[0002]

2. Description of the Related Art A magnetic tape wound around a part of a peripheral surface of a drum composed of an upper drum and a lower drum is run at a predetermined running speed, and recording and reproducing operations are performed by a rotary magnetic head. The helical scan type magnetic recording / reproducing apparatus described above has been widely used as a VTR (VCR). In the helical scan type magnetic recording / reproducing apparatus described above, as one means for achieving high-density recording, a pair of rotating magnetic heads having magnetic air gaps having opposite azimuth angles, that is, A rotating magnetic head having a magnetic gap in which the azimuth angle of the magnetic gap is set at a predetermined angle of 90 degrees or less clockwise with respect to the width direction of the recording mark, and the azimuth angle of the magnetic gap in the width direction of the recording mark And a rotating magnetic head having a magnetic air gap set at a predetermined angle of 90 degrees or less counterclockwise.
The upper drum provided at the symmetric position of 0 degrees is rotated at a predetermined rotation speed, and the position of the reference edge of the magnetic tape that is obliquely wound around at least a part of the peripheral surface of the drum is moved to the lower drum. The magnetic tape traveling at a predetermined traveling speed while being regulated by the provided guide portion is sequentially and alternately helically scanned by the pair of rotating magnetic heads, and each rotation of the pair of rotating magnetic heads is performed. In accordance with the rotation of the magnetic head every 180 degrees, a sequential recording mark by a signal to be recorded is sequentially recorded on a magnetic tape in a state adjacent to the magnetic tape, or the recorded information in the recording mark is reproduced. ing.

As described above, a home digital VCR (VCR) which enables helical scanning of a running magnetic tape by a rotating magnetic head to record and reproduce azimuth data on the magnetic tape is used for recording and reproducing analog signals. In addition to being widely used worldwide as a VHS (registered trademark) home digital VTR (VCR) for performing digital recording, digital data is recorded on a magnetic tape by azimuth recording.
Regarding digital VCRs for home use that can be played back, the DVC standard established as a result of discussions at the "HD Digital VCR Council", in which many VTR-related manufacturers and research laboratories from around the world participated, High-efficiency compression of image information is performed by various techniques such as discrete cosine transform (DCT), adaptive quantization, and variable-length coding, and the digital data of the highly efficient compressed image information and the digital data of acoustic information are As an SD mode signal or an HD mode signal, a high-efficiency compression mode to be applied when recording and reproducing on a magnetic tape, a configuration mode of recording data, a predetermined tape pattern, physical characteristics of a magnetic tape, a configuration mode of a cassette, And so on, and its practical use is being promoted. In the helical scan type magnetic recording / reproducing apparatus described above, the position of the rotation locus of the rotary magnetic head drawn in the space by the rotary magnetic head is under the condition that the tilt angle of the rotary shaft of the rotary magnetic head does not change. Is always constant.

Incidentally, some magnetic recording / reproducing apparatuses (tape recorders) for audio signals have conventionally been provided with an auto-reverse mechanism for automatically performing reciprocating recording / reproducing operations. In the magnetic recording / reproducing apparatus, the normal cassette tape can be used in a state of being used as a so-called endless tape by using the above-mentioned auto reverse function. And in a state like a so-called endless tape,
If there is a VTR that can use a magnetic tape, it can be effectively used for purposes such as crime prevention, surveillance, education, and advertising. That is, a helical scanning type magnetic recording / reproducing apparatus configured to perform a continuous recording / reproducing operation by reciprocating a single magnetic tape,
For example, it can be used for presentations where the same contents are repeatedly reproduced and used, for security where it is desired to always be able to record the latest information, and many other usage modes.

However, in the helical scan type magnetic recording / reproducing apparatus, the recording trace pattern (track pattern) formed on the magnetic tape according to the rotation locus of the rotating magnetic head is based on the diameter of the drum, the number of rotations of the rotating magnetic head, and the number of rotations. Since it is determined by various conditions such as the rotation direction of the magnetic head, the traveling speed of the magnetic tape, the traveling direction of the magnetic tape, the track angle, the head track width, and the recording area width of the magnetic tape,
When a helical scan type magnetic recording / reproducing apparatus runs a magnetic tape by switching between a forward direction and a reverse direction, the rotation trajectory of the rotating magnetic head is different due to a change in the running direction of the magnetic tape. (See FIG. 10). Therefore, configuring a helical scan type magnetic recording / reproducing apparatus having a normal configuration as a helical scan type magnetic recording / reproducing apparatus capable of performing a reciprocal recording / reproducing operation requires a tape recorder for an audio signal to perform reciprocal recording / reproducing. Unlike the case of being configured as an operation type, it cannot be easily realized.

That is, in order to perform a recording / reproducing operation by a helical scan type magnetic recording / reproducing apparatus, when the magnetic tape is run by switching the running direction between a forward direction and a reverse direction, the magnetic tape moves in the forward direction. A recording mark formed on the magnetic tape by the rotating magnetic head when traveling and a recording mark formed on the magnetic tape by the rotating magnetic head when the magnetic tape travels in a crossing state ( 10 (see FIG. 10), it is clear that the recorded signal recorded in the recording trace cannot be accurately reproduced from the rotating magnetic head when the reproducing operation is performed. In particular, a helical scan type digital magnetic recording / reproducing apparatus needs to be reproduced as a signal of a signal level which can be corrected. This is a great obstacle to the configuration of the magnetic recording / reproducing device.

By the way, when the recording operation for a long time is continued by the conventional general helical scan type magnetic recording / reproducing apparatus, the recording operation on one magnetic tape usually starts at the winding start end of the magnetic tape. Each time the recording operation on the magnetic tape is completed, another magnetic tape, a tape cassette, or the like is successively mounted on the magnetic recording / reproducing apparatus so that the recording operation is continued. Or rewind the magnetic tape recorded from the beginning of the winding to the end of the winding to the beginning of the winding and continue the recording operation from the beginning of the winding of the magnetic tape again. It is necessary to do.

As a helical scan type magnetic recording / reproducing apparatus capable of performing a reciprocating recording / reproducing operation without performing the above-mentioned complicated operations, a helical scan type magnetic recording / reproducing apparatus of the Philips V2000 type has conventionally been used. As described above, the recording area of the magnetic tape is divided into upper and lower stages in the width direction of the tape so that the signal recording operation for the two divided recording areas is performed in series on the time axis. , Japanese Patent Laid-Open No. 50-853
As in the helical scan type magnetic recording / reproducing apparatus disclosed in Japanese Patent Application Publication No. 16-216, each of the forward and backward paths of the magnetic tape reciprocatingly traveling for reciprocal recording corresponds to the rotational locus of the rotating magnetic head. Various proposals have been made such that a recording mark recorded on a magnetic tape is formed in a comb shape on a running magnetic tape.

[0009]

SUMMARY OF THE INVENTION By the way, helical
When the reciprocating recording operation is performed by the scan type magnetic recording / reproducing apparatus, the magnetic tape is traveling at a predetermined traveling speed in the forward direction (forward direction) under the control of the capstan control system during the outward recording. Also, at the time of return travel recording, under the control of the capstan control system, after the traveling direction is changed in the reverse direction (the traveling direction is reversed), the vehicle is driven in the reverse direction at a predetermined traveling speed. Thus, the traveling direction of the magnetic tape at the time of forward pass recording and at the time of backward pass recording is sequentially changed (reversed) alternately in the forward direction and the reverse direction. In the reversing operation of the traveling direction of the magnetic tape during the reciprocating recording operation, the traveling of the magnetic tape is performed by the operation of the capstan control system by detecting the reversal position information of the traveling direction from the magnetic tape. After stopping, the running direction of the magnetic tape is reversed, and the magnetic tape is run in the running direction opposite to the running direction up to that time. The reversal operation of the traveling direction of the magnetic tape performed when the forward recording operation and the backward recording operation are changed is performed instantaneously, and the magnetic tape always travels at a predetermined traveling speed even if the traveling direction is reversed. If it is in the state, even if the reciprocating recording operation is performed,
Recording can be performed on a magnetic tape in a state where no loss occurs in a signal to be recorded.

However, the operation of the mechanical components such as the capstan motor provided in the capstan control system used for the running operation of the magnetic tape is performed due to the inertia of the mechanical components. For example, the operation of reversing the running direction of the magnetic tape requires about 0.5 seconds. Also, even if the running direction of the magnetic tape is changed, the mechanism used to control the angle between the rotation locus of the rotary magnetic head and the reference edge of the magnetic tape to be the same predetermined angle. For the operation, for example, a time of about 0.5 seconds is required. Then, even if the control operations described above are performed simultaneously, the magnetic tape is reversed from the specific one direction from the point of the recording operation in the running state of the magnetic tape in one specific direction. It takes about 0.5 to 1 second to change to the traveling state in the traveling direction and start the recording operation.

Since it is impossible to record a recording signal on the magnetic tape at the above-mentioned time, the recording signal is lost during the period required for the reversal operation of the running direction of the magnetic tape. Will be. As a means for solving the above problem, Japanese Patent Application Laid-Open No. 9-63153 discloses a helical scan type magnetic recording / reproducing apparatus configured to perform a reciprocal recording operation, even during a reversal period of a running direction of a magnetic tape. Although a technical matter has been disclosed in which recording can be performed on a magnetic tape in a state where a recording signal is not lost, the technical means disclosed in this publication discloses a reversing operation of a running direction of a magnetic tape during reciprocal recording. In order to record / reproduce the signal during the period during which the signal cannot be recorded via the memory, the signal at a fixed interval of the input data is compressed and recorded / reproduced on the time axis. And the recording operation can be continued continuously. However, in order to implement the above solution, there is a problem in that a circuit configuration for performing the time axis compression / expansion of the signal becomes complicated and the frequency band of the recording signal is widened.

[0012]

SUMMARY OF THE INVENTION The present invention relates to an upper drum 18;
An unrecorded area having a width of one recording mark is formed on the magnetic tape running in the forward direction by the first and second rotating magnetic heads having magnetic gaps of the same azimuth angle provided at positions symmetrical to 0 degrees. In this state, recording marks are sequentially formed, and the azimuth angle differs from the azimuth angle of the magnetic gap of the first and second rotating magnetic heads provided at 180-degree symmetrical positions on the upper drum. With the third and fourth rotating magnetic heads having magnetic gaps having the same azimuth angle, the magnetic tape running in the opposite direction is
The magnetic tape is driven so that successive recording marks are recorded and formed in an unrecorded area of one recording mark width formed on the magnetic tape during the recording operation by the first and second rotating magnetic heads. The tape travel control means and the angle formed between the rotation locus of each rotary magnetic head and the reference edge of the magnetic tape are controlled to be the same predetermined angle regardless of whether the travel direction of the magnetic tape is forward or reverse. Means for intermittently storing an input information signal in a memory during a tape reversal period of a predetermined time length set in advance for a reversal operation of a running direction of a magnetic tape in a helical scan type magnetic recording / reproducing apparatus comprising Means for switching between the input information signal and the information signal read out from the memory, and a signal switching means for outputting the information signal. The magnetic tape is driven at a predetermined running speed after the running direction is reversed. At the time when the recording operation is resumed after the recording operation is performed, the information signal read from the memory by the signal switching means is used as a recording signal, and the recording operation described above is performed. A magnetic recording / reproducing apparatus comprising: means for allowing the input information signal to be used as a recording signal by the signal switching means after a predetermined time has elapsed from the time of restart of the upper drum and the lower drum. The magnetic tape wound around a part of the peripheral surface of the drum runs at a predetermined running speed, and the recording / reproducing operation of the information signal targeted for recording is performed by the rotating magnetic head mounted on the upper drum. In which the azimuth angle is set to a predetermined angle of 90 degrees or less clockwise with respect to the width direction of the recording trace in the helical scan type magnetic recording / reproducing apparatus for performing A first rotating magnetic head having a gap, and a second rotating magnetic head having a magnetic gap having the same azimuth angle as the first rotating magnetic head are mounted on the upper drum at the same mounting height. And a magnetic gap whose azimuth angle is set to a predetermined angle of 90 degrees or less counterclockwise with respect to the width direction of the recording trace. The third rotating magnetic head is provided at a mounting height such that recording marks adjacent to the recording marks recorded on the magnetic tape by the first rotating magnetic head can be formed. A fourth rotating magnetic head having a magnetic air gap of the same azimuth angle as the third rotating magnetic head is placed at a position 180 degrees symmetrical with respect to the third rotating magnetic head with respect to the center axis of the drum as a center of symmetry. Means for rotating the upper drum provided at the same mounting height as that of the third rotating magnetic head at a specific number of rotations only in a predetermined specific rotating direction; Means for controlling the angle between the rotation locus of the head and the reference edge of the magnetic tape so that the magnetic tape travels in the forward direction or the reverse direction at the same predetermined angle, and In a running state, the first (or third) rotating magnetic head and the second (or fourth) rotating magnetic head sequentially move between adjacent recording marks formed on the magnetic tape. The magnetic tape is running at a predetermined running speed in a direction opposite to the above-described specific one direction while running at a predetermined running speed such that an unrecorded area having at least one recording mark width is formed. State smell In a state where the magnetic tape is traveling in the specific direction that the first (or third)
A third (or fourth) rotating magnetic head sequentially records at a position of an unrecorded area of at least one recording mark width formed between adjacent recording marks, and a third (or fourth) rotating magnetic head. Or means for causing the magnetic tape to run at a predetermined running speed and running phase so that sequential recording marks are formed by the first) rotating magnetic head and the fourth (or second) rotating magnetic head; As for the input information signal in the tape reversal period of a predetermined time length set in advance for the reversal operation of the running direction of the tape, the time signal corresponding to one recording trace period on the magnetic tape is used as a unit information signal, and Means for intermittently storing in the memory the information signal of every other unit in the information signal of the sequential unit serially arranged on the axis; and the input information signal and the information signal read from the memory. A signal switching means for outputting a signal from the memory by the signal switching means when the magnetic tape is running at a predetermined running speed after the running direction is reversed and the recording operation is restarted. The read information signal is used as a recording signal, and the input information signal is used as a recording signal by the signal switching means after a lapse of a predetermined time from the point at which the above-described recording operation is restarted. A magnetic recording / reproducing apparatus comprising:

[0013]

FIG. 1 is a block diagram showing a schematic configuration of an example of a magnetic recording / reproducing apparatus according to the present invention. FIG.
In the magnetic recording / reproducing apparatus shown in FIG. 1, reference numeral 1 denotes an input terminal of a recording target signal such as an image signal and an audio signal to be recorded. Reference numeral 3 denotes a signal processing unit of a recording system and a reproduction system. The signal processing unit 3 of the recording system and the reproduction system includes a signal processing unit 43 for a tape running direction inversion period and a recording and reproduction signal processing unit 42. Have. The signal processing unit 43 in the tape running direction inversion period in the signal processing unit 3 of the recording system and the reproduction system includes, for example, as shown in FIG. It may be configured to include a timing signal generator 39 and a signal path changeover switch 40.

Signal processing unit 43 during tape running direction reversal period
When the magnetic recording / reproducing apparatus performs the reciprocal recording operation, the switching control signal generated from the timing signal generator 39 is changed based on the control signal supplied from the main control unit (system control) 5 to perform recording / reproducing switching. Switches 37 and 41,
The memory 38 supplies a write / read timing signal of the memory generated by the timing signal generator 39 to the memory 38. As a result, the signal processing unit 43 in the running direction reversal period of the tape,
When the running direction of the magnetic tape is changed from the forward direction to the reverse direction, or when the running direction of the magnetic tape is changed from the reverse direction to the forward direction, during a preset tape running direction inversion period, as described later. By performing a proper signal processing operation, a signal loss substantially does not occur in the recording signal recorded on the magnetic tape.

When the recording signal to be recorded on the magnetic tape T by the rotating magnetic head H is an analog signal, the recording / reproducing signal processing section 42 in the signal processing section 3 of the recording and reproducing systems, Generates and outputs a recording signal in the form of an analog signal of a modulated wave signal, and
When the recording signal to be recorded on the magnetic tape by the rotating magnetic head is a digital signal, the recording target signal supplied to the input terminal 1 during the recording operation is converted into a digital signal, and then a DCT block is formed and a DCT operation is performed. , Quantization and variable-length coding, addition of an error correction code, and other necessary signal processing to perform
Record information for each book has an insert information area, audio signal area,
The recording data is output as a recording signal as recording data of a signal format in a state of being divided into respective areas such as a video signal area and a subcode area. The recording signal is supplied to the rotating magnetic head via a head switch.

The main control unit (system controller) 5 includes:
For example, a microprocessor, a read-only memory (R
AM), a memory including a read only memory (ROM) and the like can be used. The main control unit 5 controls various components of the magnetic recording / reproducing apparatus, for example, the drum rotation control unit 6, a magnetic tape traveling speed and a traveling phase control system (capacity) in accordance with input information from an operation unit (not shown). A control signal is supplied to the stun control system 32, the drum tilt control unit 8, and the like to control the operation of each of the components described above. The main controller (system controller) 5 causes the magnetic tape T to record an inversion signal of the running direction of the magnetic tape at the time of the first outward recording operation.

The inversion signal of the traveling direction of the magnetic tape is the control head 4 illustrated in FIG.
7, the pulse width (or duty cycle) of the control signal CTL recorded on the control track of the magnetic tape T is different from other control signals CTL, such as CTLa and CTLb in FIG. You may. Note that, as in the above example, a reverse signal of the running direction of the magnetic tape may be recorded in a recording mark formed by the rotating magnetic head without using a fixed control head. The drum rotation control unit 6 includes a drum rotation signal DFG generated by a drum frequency generator in a signal generator 11 attached to a rotation shaft of a drum motor 7 and a drum rotation phase generated by a drum rotation phase signal generator. The signal DPG is used to control the rotating magnetic head (upper drum) to rotate at a predetermined rotation speed and rotation phase. Further, the capstan control system 32 operates so as to cause the magnetic tape to run at a predetermined tape running speed in a predetermined running direction in accordance with forward and backward recording.

A drum tilt control unit (drum tilt control mechanism) 8 to which a control signal is supplied from the main control unit 5 is provided.
A magnetic tape running at a predetermined magnetic tape traveling speed in a forward direction (for example, the direction of arrow b shown in FIG. 1) or in a reverse direction (for example, the direction of arrow -b shown in FIG. 1) is provided with a rotating magnetic tape. The drum tilt control unit (drum tilt control mechanism unit) so that the angle formed between the rotation locus of the head H and the reference edge of the magnetic tape is the same as the reference track angle of the recording mark formed on the magnetic tape. (8) The center angle of the drum is inclined by the operation of (8). A reproduced signal reproduced by the rotating magnetic head H during the reproducing operation is given to the signal processing unit 3 of the recording system and the reproducing system. When the reproduced signal reproduced from the rotating magnetic head H is an analog signal,
After the demodulation operation and other predetermined signal processing are performed in the recording / reproducing signal processing unit 42 provided in the recording / reproducing signal processing unit 3, the reproduction signal is changed to the fixed contact point P of the changeover switch 37. The output is sent to the output terminal 2 via the path of the movable contact v → the fixed contact t of the switch 40 → the movable contact v → the fixed contact P of the switch 41 → the movable contact v.

When the reproduction signal reproduced by the rotary magnetic head H is a digital signal, the recording / reproduction signal processing section 42 provided in the signal processing section 3 of the recording system and the reproduction system performs the above-mentioned operation. After the reproduced signal is equalized in waveform by the waveform equivalent circuit, the digital data is stored in the memory via the code detection circuit and the phase locked loop (PLL). The digital data of the digital memory is
After being read at the read permission signal timing supplied from the main control unit 5, the bit stream is formed into a serial bit stream on the time axis, and the error correction circuit performs error correction signal processing. Next, the digital data output after the variable-length code has been decoded by the variable-length decoding unit,
The inverse DCT is performed by the inverse DCT circuit and is stored in the frame memory. The digital data read from the frame memory is transferred to the fixed contact P of the changeover switch 37 → the movable contact v → the fixed contact t of the changeover switch 40 → the same. Movable contact v →
The signal is sent to the output terminal 2 via a path from the fixed contact P of the changeover switch 41 to the movable contact v.

The frequency dividing circuit 33 of the control system (capstan control system) 32 for controlling the running speed and running phase of the magnetic tape, when the magnetic recording / reproducing apparatus performs the reciprocating recording / reproducing operation, makes the magnetic tape T operate at the normal running speed. (The same recording trace pattern as that recorded on the recorded magnetic tape in the state where the reciprocating recording operation has been performed,
(A traveling speed at which recording can be performed on the magnetic tape T by two rotating magnetic heads provided at positions symmetrical to 0 degrees)
Capstan motor 9 that rotationally drives capstan 30
The frequency of the output signal CAPFG of the frequency generator 10 attached to the rotating shaft of
4

The output signal from the frequency-to-voltage converter 34 is a speed control signal, and the tracking control signal supplied from the main control unit 5 is added to the speed control signal by an adding circuit 35 to form a driving circuit. The output signal from the driving circuit 36 is supplied to the capstan motor 9. As a result, the magnetic tape T sandwiched between the capstan 30 and the pinch roller 31
Is controlled so as to run at a predetermined running speed and running phase. As a result, the rotation trajectory of the rotary magnetic head H can cause the magnetic tape T to form a recording trace pattern as shown in FIG. In FIG. 5 (the same applies to FIG. 7), A1, A2,..., B1, B2,... Indicate recording marks sequentially formed on a magnetic tape by rotating magnetic heads having different azimuth angles of magnetic gaps. , B1, B2,..., B1, B2,... Are also used in the following description to indicate the recording signals recorded on the respective recording traces).

As described above, the rotational locus of the rotary magnetic head H when the magnetic tape T is traveling in the forward direction and the rotational locus of the rotary magnetic head H when the magnetic tape is traveling in the reverse direction 10 is completely different from that shown in FIG. 10, and the reciprocating recording / reproducing operation cannot be properly performed as it is. Therefore, the angle between the rotation locus of the rotary magnetic head H when the magnetic tape T is traveling in the forward direction and the reference edge of the magnetic tape, and the rotational magnetic head when the magnetic tape is traveling in the reverse direction. The angle formed between the rotation locus of H and the reference edge of the magnetic tape is controlled so as to always coincide with the predetermined track angle regardless of whether the running direction of the magnetic tape T is the forward direction or the reverse direction. Must be.

As described above, even when the running direction of the magnetic tape T is changed, the angle between the rotation trajectory of the rotary magnetic head H and the reference edge of the magnetic tape always coincides with the predetermined track angle. The components that perform the operation are:
The main controller (system controller) 5 and the drum tilt controller 8 in FIG. 1 are illustrated, and the system controller 5, the drum tilt controller 8 and the tilt correction mechanism in FIG. 3, and the mechanism shown in FIG. 4 are illustrated. I have. First, referring to FIG. 3, the rotation locus drawn on the magnetic tape T by the rotating magnetic head is controlled to be at an arbitrary predetermined angle with respect to the reference edge Te of the magnetic tape T, or the lead ring L
An outline of the configuration principle and operation principle of the tilt correction mechanism for making the position regulating surface G of r coincide with the movement locus of the running magnetic tape T will be described.

In FIG. 3, DB is a drum base, and a drum structure DA including an upper drum Du, a lower drum Dd, and a lead ring Lr is supported by the drum base DB. The upper drum Du is a drum structure D
A lower bearing Dd is fixed to the center axis of the drum assembly DA by a bearing (not shown) mounted on the center axis 12 of A in a rotatable manner with respect to the center axis of the drum assembly DA. Have been. The lead ring Lr, which functions as a guide for the reference edge Te (see FIG. 1) of the magnetic tape T, is formed separately from the lower drum Dd and is close to the outer peripheral portion 13 below the lower drum Dd. Further, the knife ring E (see FIG. 4) provided on the inner periphery of the lead ring Lr coaxially fits (not shown) with the lower protrusion of the lower drum Dd.

As illustrated in FIG. 3 (an exploded perspective view of a specific configuration is shown in FIG. 4), the drum tilt control unit 8 includes a tilt drive motor (DD in FIG. 3) as a power source. Motor) 14, and reduction mechanisms 15, 16 including a plurality of gears,
It includes a rotary encoder 17, a position detector (preset sensor) 18, and the like. The tilt drive motor 14 shown by a block 14 in FIG.
It also includes a motor drive control circuit. As the above-described position detector 18, for example, one having a configuration in which an arc-shaped light shielding plate is moved in an optical path in which a light emitting element and a light receiving element are arranged to face each other may be used. The position detector 18 is configured such that the signal output from the position detector 18 at the moment when the arc-shaped light shielding plate is removed from the optical path in which the light emitting element and the light receiving element are arranged to face each other is the drum described above. It is used as information indicating the reference position of the center axis 12 of the structure DA and the reference position of the lead ring Lr.

The amount of rotation of the light shielding plate from the reference position in the position detector 18 is known from the measurement of the number of pulses output from the rotary encoder 17, so that the reference position of the central axis 12 of the drum structure DA is determined. Direction and the amount of deviation from the reference position of the lead ring Lr can be obtained. The running direction and running speed of the magnetic tape T are controlled by the main control unit 5 according to various operation modes set in the main control unit (system controller) 5 of the magnetic recording / reproducing apparatus. The drum inclination control unit 8 to which the information is given,
The central axis 1 of the drum structure DA including the upper drum Du, the lower drum Dd, and the lead ring Lr in the drum structure DA.
2 in the direction of arrow 12a (or 12b) in FIG.
The screw 2 is tilted by a predetermined amount.
A control operation is performed so as to advance and retreat 6, 28.

The lead ring Lr is also tilted by a predetermined amount in a predetermined direction under the control of the drum tilt control unit 8, so that the running direction of the magnetic tape is set to either the forward or reverse direction. Even in this case, the pattern of the rotation locus drawn on the magnetic tape T by the rotation locus of the rotary magnetic head is set to a predetermined track angle, that is, a state where the inclination is corrected, and the reference edge Te of the magnetic tape is moved. The guide portion G (position regulating surface) of the lead ring coincides with the trajectory. First, in a state where the magnetic tape T is run in the forward direction (the direction of the arrow b in FIG. 1) at a predetermined running speed during a normal recording and reproducing operation, a predetermined specific rotation direction (in FIG. 2). The lower drum Dd in the case where the magnetic tape T is driven and rotated at a predetermined number of rotations in the direction indicated by the arrow a) to sequentially and alternately record and form the magnetic tape T has a bottom surface protruding from the drum base DB. Four rotation fulcrums (the rotation fulcrums 20, 2 in FIG. 4)
0, 21, 21). The lead ring Lr is the lead ring L
r, the four pivots (the pivots 2 in FIG. 4).
2, 22, 23, 23). A spring (springs 19 and 2 in FIGS. 3 and 4) is provided between the lead ring Lr and the drum base DB and between the lower drum Dd and the drum base DB, respectively.
4, 25) are mounted so that the above-mentioned parts are connected to each other in a predetermined connection state.

For example, when fast forward reproduction (FF) is performed in the same running direction as the running direction of the magnetic tape during the recording operation, the screw 29 is driven so as to push up the bottom surface of the lower drum Dd. The screw 30 is driven in a direction away from the bottom surface of the lower drum Dd, so that two of the four pivot points (rotation points 20, 20) projecting from the drum base DB are rotated. The center axis of the upper drum Du and the lower drum Dd is rotated in the direction of the arrow 12a in FIG. 3 using the two rotation fulcrums as the rotation fulcrum. You. When recording / reproduction is performed with the running direction of the magnetic tape reversed,
0 is driven so as to push up the bottom surface of the lower drum Dd, and the screw 29 is driven in a direction away from the bottom surface of the lower drum Dd. Of two rotation fulcrums (rotation fulcrums 21, 21)
Is in contact with the bottom surface of the lower drum Dd, and the central axes of the upper drum Du and the lower drum Dd rotate in the direction of the arrow 12b in FIG. Is done.

The above-mentioned driving operation for the screws 29 and 30 is performed by the operation of the driving mechanism. The drive mechanism includes a motor 14 as a power source, a speed reduction mechanism including a plurality of gears, a position detector 18, a rotary encoder 17, and the like as shown in the exploded perspective view of FIG. ing. The traveling direction and traveling speed of the magnetic tape T correspond to various operation modes, and the main control unit 5 provided in the magnetic recording / reproducing apparatus.
In response to the setting, the drum inclination control unit 8 to which the control information is given from the main control unit 5,
, The center axis of the drum structure DA including the upper drum Du, the lower drum Dd (see FIG. 3), and the lead ring Lr,
The drive mechanism is controlled to advance and retreat the screws 29 and 30 so that the screws 29 and 30 are tilted by a predetermined amount in the directions of arrows 12a (or 12b) in FIG.

For example, fast forward reproduction (FF) in the same running direction as the running direction of the magnetic tape during the recording operation
Is performed, two of the four pivots protruding from the lead ring Lr (the pivots 2).
2, 22) are in contact with the bottom surface of the lower drum Dd, and the center axis of the lead ring Lr is rotated by a predetermined amount in the direction of arrow 12a in FIG. The two screws 31, 32, which are screwed into the lead ring Lr and are provided in such a manner that the ends thereof abut on the bottom surface of the lower drum Dd, are rotated in opposite directions.

Further, when recording and reproduction are performed with the running direction of the magnetic tape reversed, the read ring Lr
Of the four turning fulcrums (turning fulcrums 23, 23) protruding from the lower drum Dd contact the bottom surface of the lower drum Dd, and turn the two turning fulcrums. As a fulcrum, the lead ring Lr is screwed into the lead ring Lr so that the center axis of the lead ring Lr is turned by a predetermined amount in the direction of arrow 12b in FIG. The two screws 31 and 32 provided in contact with the bottom surface are rotated in opposite directions.

The above-mentioned driving operation for the screws 31 and 32 is also performed by the operation of the above-mentioned driving mechanism which operates under the control of the drum inclination control unit. In response to the traveling speed being set in the main control unit 5 provided in the VTR in accordance with various operation modes, the drum inclination control unit 8 to which the control information is given from the main control unit 5 is used. , Lead Ring Lr
The drive mechanism is controlled so as to tilt by a predetermined amount in the direction of arrow 12a (or 12b) in FIG. In the above description, in order to facilitate understanding of the operation, the tilting operation of the center axis of the drum assembly by the forward and backward operations of the screws 29 and 30 and the tilting operation of the central axis of the lead ring Lr by the forward and backward operations of the screws 31 and 32 are described. Were explained as if they were performed independently. However, the screws 29 to 32 described above
The screw 30 and the screw 31 are simultaneously driven and rotated by a common power transmission mechanism, and the screw 30 and the screw 32 are simultaneously driven and rotated by a common power transmission mechanism. The operation of tilting the center axis of the drum assembly by the operation and the operation of tilting the center axis of the lead ring Lr by the advancing and retreating of the screws 31 and 32 may be performed simultaneously.

In the magnetic recording / reproducing apparatus described with reference to FIGS. 3 and 4, the rotation trace surface of the rotary magnetic head coincides with the recording trace formed on the magnetic tape by a predetermined angle. The first tilt drive means for tilting the central axes of the upper and lower drums and the rotary magnetic head is provided separately from the upper and lower drums and at the lower portion of the lower drum. A position regulating guide member (lead ring) Lr for a magnetic tape having a regulating surface G at a position of a reference edge of the magnetic tape, which is disposed in a state of approaching the outer peripheral surface of the small diameter portion 39 (see FIG. 4); A second inclination driving means for inclining the position regulating guide member of the magnetic tape so as to coincide with the reference edge position of the magnetic tape,
By inclining the lower drum and the lead ring Lr having the position regulating surface G of the reference edge of the magnetic tape as required according to various operation modes, the recording formed on the magnetic tape is performed. The track of rotation of the rotary magnetic head is made to coincide with the trace, and the reference edge Te of the magnetic tape T can be guided well by the position regulating surface G of the lead ring Lr.

When the magnetic recording / reproducing apparatus performs a reciprocating recording / reproducing operation, a predetermined control signal is supplied from the main control unit 5 to the drum inclination control unit 8, so that the drum inclination control unit 8 Regardless of whether the magnetic tape is running in the forward direction or the magnetic tape is running in the reverse direction, the angle between the rotation trajectory of the rotating magnetic head and the reference edge of the magnetic tape is always the reference track. It can be made to match the angle.

FIG. 2 is a view showing an example of the arrangement of a rotary magnetic head which can be used in the magnetic recording / reproducing apparatus of the present invention. In FIG. 2, H1 indicates the azimuth angle in the width direction of the recording mark. On the other hand, the first rotating magnetic head has a magnetic gap set at a predetermined angle of 90 degrees or less clockwise, and H2 has the same azimuth angle as that of the first rotating magnetic head. It is a second rotating magnetic head having a magnetic air gap. The first rotating magnetic head H1 and the second rotating magnetic head H2 are connected to the upper drum D
u are arranged at the same mounting height and at 180-degree symmetrical positions about the center axis of the drum.

In FIG. 2, H3 denotes a third rotating magnetic head having a magnetic gap whose azimuth angle is set to a predetermined angle of 90 degrees or less counterclockwise with respect to the width direction of the recording trace. In addition, H4 is a third rotating magnetic head having a magnetic gap having the same azimuth angle as the third rotating magnetic head described above. The third rotating magnetic head H3 and the fourth rotating magnetic head H4 are
At the same mounting height on the upper drum Du, it is disposed at a position symmetrical with respect to the center axis of the drum at 180 degrees.

The arrangement of the four rotating magnetic heads H1, H2, H3, and H4 illustrated in FIG.
Of the rotating magnetic head H1 and the third rotating magnetic head H3 are located at a small distance in the circumferential direction of the upper drum Du, at a track pitch Tp on the recorded magnetic tape after reciprocal recording has been performed. The second rotating magnetic head H2 and the fourth rotating magnetic head H4 are attached at a small interval in the circumferential direction of the upper drum Du. At a position, the tape is attached so as to have a height difference corresponding to the track pitch Tp of the recorded magnetic tape after reciprocal recording has been performed.

The arrangement of the four rotating magnetic heads H1, H2, H3, H4 illustrated in FIG. 2B is symmetrical with respect to the center axis of the upper drum Du at the same mounting height. A first rotating magnetic head H1 and a second rotating magnetic head H2 disposed at 180-degree symmetric positions with respect to the center.
In contrast, the third rotating magnetic head H3 and the fourth rotating magnetic head H4 are different from the first rotating magnetic head H1 described above.
The second rotating magnetic head H2 is arranged on a straight line passing through the center of the drum at right angles to a straight line connecting the rotating magnetic head and the second rotating magnetic head H2. That is,
The four rotating magnetic heads H1, H2, H3, and H4 illustrated in FIG. 2B have two rotating magnetic heads adjacent to each other in the circumferential direction of the upper drum Du from the center position of the drum. The upper drum Du is arranged in such an arrangement that the central angles when viewed are 90 degrees.

Now, the magnetic recording / reproducing apparatus of the present invention will be described with reference to FIG.
When a forward magnetic recording (reproducing) operation is performed using a rotating magnetic head having a configuration as shown in FIG. 1, the capstan control system operates according to a control signal from the main control unit 5.
A predetermined traveling speed at the time of reciprocal recording (reproducing) operation of the magnetic tape T [only two rotating magnetic heads (for example, two rotating magnetic heads H1 and H2) provided at 180-degree symmetric positions of the upper drum Du]. Is used to form a track pattern in a state in which recording is performed in close contact with the magnetic tape, so that the running speed is twice the running speed of the magnetic tape. Control operation is performed so that Further, the control signal is supplied from the main control unit 5 to the drum inclination control unit 8 to which the control signal corresponding to the forward recording (reproduction) is given, and the drum inclination control unit 8 travels in the forward direction at a predetermined traveling speed. Reference edge Te of magnetic tape T
The position of the rotational locus of the rotary magnetic head is controlled so that the angle between the rotational magnetic head and the rotational locus of the rotary magnetic head becomes a predetermined track angle.

When the magnetic recording / reproducing apparatus of the present invention performs the outward recording (reproducing) operation, for example, a pair of rotating magnetic heads H1 and H2 is used. When used during the outward recording (reproducing) operation, a pair of rotating magnetic heads H3 and H4 is used during the backward recording (reproducing) operation. On the contrary, the pair of rotating magnetic heads used during the outward recording operation are two rotating magnetic heads, the third rotating magnetic head H3 and the fourth rotating magnetic head H4. In this case, the pair of rotating magnetic heads used in the backward recording operation include a first rotating magnetic head H1 and a second rotating magnetic head H2.
And the two rotating magnetic heads. In the following description, a pair of rotating magnetic heads used during the outward recording operation are two rotating magnetic heads, a first rotating magnetic head H1 and a second rotating magnetic head H2, and A description will be given by taking as an example a case where the pair of rotating magnetic heads used in the backward recording operation are two rotating magnetic heads, a third rotating magnetic head H3 and a fourth rotating magnetic head H4. ing.

Incidentally, the reciprocating recording (reproducing) operation in the magnetic recording / reproducing apparatus of the present invention, as described above, includes the first rotating magnetic head H1 and the second rotating magnetic head H1 during the outward recording (reproducing) operation.
Of the sequential recording marks A1, A2, A3 formed on the magnetic tape T by the rotating magnetic head H2 of the first type.
The recording trace recorded on the magnetic tape T by the rotating magnetic head H1 is A1 → A3 →, and the recording trace recorded on the magnetic tape T by the second rotating magnetic head H2 is A2.
The recording marks A1, A3,... Recorded on the magnetic tape T by the first rotating magnetic head H1 and the recording marks A2,... T recorded on the magnetic tape T by the second rotating magnetic head H2. An unrecorded area having a width of one recording trace is provided between adjacent recording traces in the recording traces that are sequentially arranged alternately.

During the recording (reproducing) operation on the return path, the third rotating magnetic head H3 and the fourth rotating magnetic head H4 use the third rotating magnetic head H4 to form a third one of the successive recording marks formed on the magnetic tape T. Tape T by the rotating magnetic head H3
Are recorded on the magnetic tape T by the fourth rotating magnetic head H4, and are recorded on the magnetic tape T by the fourth rotating magnetic head H4. 3, by the fourth rotating magnetic heads H3 and H4,
The above-mentioned recording traces B1, B recorded and formed on the magnetic tape T
Are provided between adjacent recording traces in the recording traces sequentially and alternately arranged on the magnetic tape T by the first and second rotating magnetic heads H1 and H2 during the recording (reproducing) operation on the outward path. It is recorded in the place of the unrecorded area having the width of one recording trace.

When the magnetic recording / reproducing apparatus of the present invention performs a reciprocating recording (reproducing) operation, the capstan control system 32 causes the magnetic tape T to reciprocate recording (reproducing) by a control signal from the main control unit 5. A predetermined traveling speed during operation (a traveling speed twice as high as the traveling speed of the magnetic tape when a track pattern in a closely recorded state is obtained using only the two rotating magnetic heads H1 and H2) )
Thus, control is performed such that the vehicle travels in the forward direction (the direction of the arrow b in the figure). Further, the main control unit 5 gives a control signal to the drum inclination control unit 8, and the operation of the drum inclination control unit 8 causes the rotation locus of the rotating magnetic head to be at a predetermined track angle during the recording (reproduction) operation on the outward path. The position of the rotation trajectory of the rotary magnetic head is controlled so as to be as follows.

Thus, when the magnetic recording / reproducing apparatus is performing a reciprocating recording (reproducing) operation, the first rotating magnetic head H is applied to the magnetic tape T running at a predetermined running speed.
The first to fourth magnetic heads H4, or the first and second rotating magnetic heads H1 and H2 (or the third and fourth rotating magnetic heads H3 and H4) sequentially form recording traces based on recording signals. Or the recorded signal is reproduced from the recording trace of the magnetic tape T.

Next, the end of the magnetic tape T is detected by means for detecting the end of the magnetic tape (not shown) (for example, an optical detecting means or a means for detecting a turn-point indication signal recorded in advance on the magnetic tape). Alternatively, the turning point is detected and the information is provided to the main control unit 5, whereby the main control unit 5 provides a control signal to the drum inclination control unit 8, and the operation of the drum inclination control unit 8 causes At the time of recording (reproducing) operation, a control operation is performed to change the position of the rotational locus of the rotary magnetic head so that the rotational locus of the rotary magnetic head has a predetermined track angle. The main control unit 5 also supplies a predetermined control signal to a capstan control system (not shown) so that the capstan control system can rotate the magnetic tape T in the reverse direction at a predetermined traveling speed during the reciprocating recording / reproducing operation. (In the direction of arrow -b in the figure).

When the magnetic recording / reproducing apparatus is performing the recording (reproducing) operation on the return path, and the magnetic tape is traveling in the reverse direction at the above-mentioned predetermined traveling speed, the third rotating magnetic field Head H3 and fourth rotating magnetic head H
No. 4 indicates that the first rotating magnetic head H1 and the second rotating magnetic head H2 have unrecorded one recording mark width between successive recording marks that have been sequentially recorded and formed on the magnetic tape T. The recording signal is recorded at the position of the recording trace in the area sequentially, or the recording signal is reproduced from the recording trace at the position.

When the magnetic recording / reproducing apparatus performs the reciprocating recording operation as described above, the magnetic tape T is moved in the reverse direction from the recording operation in the forward path performed with the magnetic tape T running in the forward direction. When the operation is changed to the recording operation on the return path performed while the magnetic tape T is running, or conversely, the recording operation on the return path performed when the magnetic tape T is driven in the reverse direction is sequentially performed. When the operation is changed to the recording operation in the forward path performed in the traveling direction, the magnetic tape T is temporarily stopped, and then travels in the traveling direction opposite to the traveling direction up to that time. .

Accordingly, the state in which the magnetic tape T is traveling at a predetermined traveling speed required for the recording / reproducing operation in one specific direction and the direction necessary for the recording / reproducing operation in the direction opposite to the specific one direction is required. Until the vehicle travels at a predetermined traveling speed, a period in which the vehicle travels at a traveling speed (including a stop state) different from the predetermined traveling speed required for the recording / reproducing operation described above is required. This period is a recording (reproduction) disabled period during which normal recording and reproduction operations cannot be performed. If the information signal to be recorded by the magnetic recording / reproducing apparatus is continuous on the time axis, the presence of the above-mentioned non-recordable period in the magnetic recording / reproducing apparatus may cause the magnetic tape to fail. In T, a part of the information signal to be recorded cannot be recorded, and the signal is lost.

FIG. 6A is a diagram showing, as input signals, information signals to be recorded by the magnetic recording / reproducing apparatus, and A1, A2, A3,.
1, B2, B3,... Are information signals having a time length in which information signals in a continuous state on the time axis to be recorded are recorded in one recording mark formed on the magnetic tape T. (Information signals in units) are shown separately. FIG. 6 illustrates a state in which information signals A1, A2, and A3 in units are recorded by a forward recording operation on a magnetic tape traveling at a predetermined traveling speed required for recording and reproduction in the forward direction. Have been. In FIG. 6, it is assumed that the reversing operation of the running direction of the magnetic tape T has started at time t1.

In the non-recordable period from the time t1 to the time ta in FIG. 6B, when the recording operation of the magnetic recording / reproducing apparatus is changed from the state of the forward recording operation to the state of the backward recording operation. From the state in which the magnetic tape T is traveling at a predetermined traveling speed required for the recording / reproducing operation in the forward direction, after being stopped at the time t1, the traveling is started in the reverse direction, and the recording / reproducing operation is started. This is a period until time ta when the vehicle is traveling at a predetermined traveling speed, and as described above, the period is, for example, about 1 second. Further, the operation of the drum tilt control unit 8 performed in accordance with the operation of changing the running direction of the magnetic tape T is also performed during the above-mentioned recording disabled period from time t1 to time ta.

The input signals B1, B supplied during the above-mentioned non-recordable period from time t1 to time ta.
2 and B3 cannot be recorded on the magnetic tape T as a matter of course, and the input signals B4, B5, B6... Therefore, the input signals B1, B2, and B3 supplied during the above-described non-recordable period are missing signals. Therefore, in the magnetic recording and reproducing apparatus of the present invention,
A tape reversal period (twice from time t1 to time t2) having a time length twice as long as the above-described non-recordable period from time t1 to time ta.
To an inversion period) so that the information signal of every other unit of the information signal of the continuous unit on the time axis in the tape inversion period can be recorded on the magnetic tape T. The information signals during the above-mentioned non-recordable period can be recorded on the magnetic tape T without being lost.

The above-described recording operation during the tape inversion period is performed by the signal processing unit 43 during the tape running direction inversion period provided in the signal processing unit 3 of the recording system and the reproduction system in FIG.
The following operation is performed. The end of the magnetic tape T is detected by a detecting means (not shown) of the end of the magnetic tape (for example, an optical detecting means or a detecting means of a turn-point indicating signal previously recorded on the magnetic tape).
Alternatively, a turning point is detected, and the information is sent to the main control unit 5.
, The main control unit 5 gives a control signal to the drum inclination control unit 8, and the operation of the drum inclination control unit 8
During the recording (reproducing) operation on the outward path, a control operation is performed to change the position of the rotational locus of the rotary magnetic head so that the rotational locus of the rotary magnetic head becomes a predetermined track angle. A predetermined control signal is supplied to a capstan control system (not shown) so that the capstan control system causes the running direction of the magnetic tape T to run in a direction opposite to the running direction of the magnetic tape up to that time. Operation.

The main control section 5 supplies a control signal to a timing generator 39 in the signal processing section 43 in the tape running direction inversion period provided in the signal processing section 3 of the recording system and the reproduction system, and In the tape reversal period (the period from time t1 to time t2... Reversal period) having a time length twice as long as the non-recordable period from time t1 to time ta in No. 6, the timing signal generator 39 generates the signal. The memory 38 operates so that the input information signal is intermittently stored at a predetermined timing or the stored input information signal is read in accordance with the timing signals for writing and reading the memory 38. As the memory 38, a Fifo memory may be used.

The above-mentioned timing signal generator 39
The switch 40 on the signal path to which the switching control signal is supplied from the input terminal 1 → the fixed contact R of the switch 37 →
In the path of the movable contact v, the movable contact v
Is supplied to the recording / reproducing signal processing unit 42 via the fixed contact t and the movable contact v of the changeover switch 40 in the signal path, and the movable contact v and the fixed contact R of the changeover switch 41. Or the information signal read from the memory 38 is transmitted to the signal path changeover switch 40.
Through a fixed contact m and a movable contact v of the switch 41 and a movable contact v and a fixed contact R of the changeover switch 41.
Or a signal path switching operation.

Next, the operation of the signal processing section 43 during the above-described tape running direction inversion period will be specifically described with reference to a signal arrangement on the time axis illustrated in FIG. Time t1 at which the traveling of the magnetic tape T is stopped after the outward recording operation is completed.
, The inversion period starts. The movable contact v of the changeover switch 40 of the signal path, which has been switched to the fixed contact t during the forward recording operation, is connected to the timing signal generator 39.
At the time t
The state is switched to the fixed contact m side. Also, at the time t1
In response to the write signal supplied from the timing signal generator 39, the information signal B1 in the unit of the input information signal is stored in the memory 38. The information signal B1 in the unit described above.
Is discarded without being stored in the memory 38.

Next, the unit information signal B3 is stored in the memory 38 by the write signal supplied from the timing signal generator 39, and during the period of the next unit information signal B4, the memory 38 performs a read operation as described later. Is performed, the unit information signal B4 is discarded without being stored in the memory 38. The next unit information signal B5 after the unit information signal B4 is stored in the memory 38, and the next unit information signal B6 is discarded without being stored in the memory 38. Thus, the timing signal generator 3 is stored in the memory 38.
Since the write signal supplied from No. 9 stores information signals of every other unit in the information signal of the next unit in the input information signal continuously supplied on the time axis during the inversion period. Eventually, the memory 38 stores an information signal which is の of the input information signal during the inversion period.

The unit information signals sequentially stored in the memory 38 as described above also include the unit information signals B1 and B3 during the non-recordable period.
Information signals during the non-recordable period during which recording on the magnetic tape T could not be performed can also be recorded on the magnetic tape T as described later. Now, in the example shown in FIG. 6, at the time ta when the information signal B3 of the unit described above is stored in the memory 38,
After the non-recordable period is over, the magnetic tape T is running at a predetermined traveling speed at which the return path recording operation is possible, and the recording operation on the return path is started from the time ta described above.

When the read signal is supplied from the timing signal generator 39 to the memory 38 at the time ta, the information signal B1 in the unit stored in the memory 38 is output.
Is read out as a unit information signal C1 (the information content is the same as the information signal B1 of the unit in the non-recordable period). Memory 3
The information signal C1 read out from the unit 8 is sent to the recording / reproducing signal processing unit 42 via the fixed contact m and the movable contact v of the changeover switch 40 and the movable contact v and the fixed contact R of the changeover switch 41 in the signal path. Supplied.

Next, the unit information signal B3 stored in the memory 38 is read out as a unit information signal C2 (the information content is the same as the information signal B3 of the unit in the non-recordable period), and the information signal B3 in the signal path is read. The signal is supplied to the recording / reproducing signal processing unit 42 via the fixed contact m and the movable contact v of the changeover switch 40 and the movable contact v and the fixed contact R of the changeover switch 41. Similarly, the information signal B5 of the unit stored in the memory 38 is read out as the information signal C3 of the unit (the information content is the same as the information signal B5 of the unit of the non-recordable period). The signal is supplied to the recording / reproducing signal processing unit 42 via the fixed contact m and the movable contact v, the movable contact v of the changeover switch 41, and the fixed contact R.

At the time t2 when the reading of the information signal C3 in the unit described above is completed, the inversion period ends, and the timing signal generator 39 sends the switching control signal to the switching switch 4 in the signal path.
0, the signal path changeover switch 40
Is switched to the fixed contact t side. So,
The recording / reproducing signal processing section 42 outputs the information signals B7, B8,.
The input terminal 1 → the fixed contact R of the changeover switch 37 → the same movable contact v → the fixed contact t of the changeover switch 40 of the signal path → the same movable contact v → the movable contact v of the changeover switch 41 → recorded on the same fixed contact R It is supplied to the reproduction signal processing unit 42.

As described above, in the reciprocating recording operation of the magnetic recording / reproducing apparatus, the information signal recorded on the magnetic tape T by the special signal processing operation during the reversal period becomes the unit information signals A1, A2 in the example of FIG. , A3, C1 (= B1),
C2 (= B3), C3 (= B5), B7, B8, B9 ...
become that way. FIG. 8A shows a recording state (reproduction pattern) of a signal on a recorded magnetic tape on which an information signal of a sequential unit is recorded as described above.
FIG. 8 (b) is a time-sequential view of a reproduction signal reproduced from a recorded magnetic tape on which an information signal of a sequential unit is recorded as shown in FIG. 8 (a). 2 shows an arrangement state of information signals in the unit of.

Therefore, in the magnetic recording / reproducing apparatus of the present invention, it is possible to record on the magnetic tape T without losing the unavoidable information signal of the recording impossible period during the reversal operation of the running direction of the magnetic tape T during the reciprocal recording operation. For example,
It can be seen that the magnetic recording / reproducing apparatus which performs the reciprocal recording operation can be used very effectively even when recording information for security, since no signal is lost during the reversal operation of the running direction of the magnetic tape T.

When the magnetic recording / reproducing apparatus shown in FIG. 1 performs a reproducing operation, the switching generated by the timing signal generator 39 is performed based on the control signal supplied from the main controller 5 to the timing signal generator 39. The movable contact v of the recording / reproducing changeover switches 37 and 41 is switched to the fixed contact P side by the control signal, and the movable contact v of the signal path changeover switch 40 is fixed by supplying to the signal path changeover switch 40. It is switched to the contact t side. In the reciprocating reproducing operation in the magnetic recording and reproducing apparatus of the present invention, the recording is performed on the magnetic tape T by the first rotating magnetic head H1 and the second rotating magnetic head H2 during the forward reproducing operation as described above. A reproduction signal is obtained from the sequential recording traces A1, A2 and A3, and the recording is formed on the magnetic tape T by the third rotating magnetic head H3 and the fourth rotating magnetic head H4 during the reproducing operation on the return path. Sequential recording trace C
1 (= B1), C2 (= B3), C3 (= B5), B7
.. (See FIG. 7), a reproduction signal is obtained.

Next, FIG. 9 shows that an index signal (CTLa) giving the timing of the inversion operation detects that the recording area has entered the inversion area, and the recording marks A1, A2, and A3 before the inversion are repeated a plurality of times (2 in the illustrated example). This example shows a case in which reproduction is performed at a time to compensate for the non-reproducible period and the index signal (CTLb) is used to return to a normal reproduction state. Also, during the operation of reproducing the intermittent signal during the inversion period, the above-described sequential recording traces C1 (= B1), C2 (= B3),
Since the portion of C3 (= B5) is in the state of dropped frames, the image reproduced from this portion may feel unnatural. As a countermeasure, for example, when reproducing the recording traces C1 (= B1), C2 (= B3), and C3 (= B5), the feeding speed of the magnetic tape T is set to By reducing the speed to half or using the memory 38 used during the recording operation,
The above-mentioned recording traces C1 (= B1), C2 (= B3), C3
(= B5), B1, B1, B3, B3
By performing interpolation for the signal missing period as in B5 and B5, a reproduction result without a sense of incongruity can be obtained. The timing for changing the running speed can be easily determined by the CTLa shown in FIG.

[0065]

As is apparent from the above description, the magnetic recording / reproducing apparatus of the present invention uses the first rotating magnetic head and the second rotating magnetic head during the recording (reproducing) operation on the outward path. An unrecorded area having a width of one recording mark is provided between adjacent recording marks in successive recording marks formed on the magnetic tape T, and the third recording mark is formed during the recording (reproduction) operation on the return path. The sequential recording marks formed on the magnetic tape T by the rotary magnetic head H and the fourth rotary magnetic head form the first and second rotary magnetic heads H1 and H2 during the recording (reproducing) operation on the outward path. By magnetic tape T
The reciprocating recording / reproducing operation is performed such that recording is performed at an unrecorded area having a width of one recording trace between adjacent recording traces in recording traces which are sequentially and alternately arranged. In the reproducing apparatus, for an input information signal in a tape reversal period of a predetermined time length preset for a reversal operation of a running direction of a magnetic tape, a signal of a time length corresponding to one recording trace period on a magnetic tape is used as a unit. As the information signal, the information signal of every other unit in the information signal of the sequential unit serially arranged on the time axis is intermittently stored in the memory, and the input information signal and the information read from the memory are intermittently stored. The signal switching means outputs the signal switching means when the magnetic tape is running at a predetermined running speed after the running direction is reversed and the recording operation is restarted. Therefore, the information signal read from the memory is used as a recording signal, and the input information signal is used as a recording signal after a lapse of a predetermined time from the restart of the recording operation. Thus, in the magnetic recording / reproducing apparatus of the present invention, it is possible to record on the magnetic tape T without losing the information signal of the unavoidable non-recordable period during the reversal operation of the running direction of the magnetic tape T during the reciprocal recording operation. For example, even in the case of recording information for security by a magnetic recording / reproducing apparatus that performs a reciprocal recording operation, a signal is not lost at the time of the reversal operation of the running direction of the magnetic tape T, so that it can be used very effectively. In addition, there is an advantage that the memory to be used may be a memory having a capacity small enough to store a signal for half the inversion period. That.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a magnetic recording / reproducing apparatus of the present invention.

FIG. 2 is a diagram for explaining an arrangement mode of a rotating magnetic head.

FIG. 3 is a view showing the relationship between the reference edge of the magnetic tape and the rotation trajectory of the rotary magnetic head even when the running state of the magnetic tape changes; FIG. 4 is a diagram for explaining a configuration example of a mechanism used to adjust and change the rotation trajectory of FIG.

FIG. 4 adjusts the rotation trajectory of the rotary magnetic head so that the angle formed between the reference edge of the magnetic tape and the rotation trajectory of the rotary magnetic head matches a specific track angle even when the running speed of the magnetic tape changes. It is a perspective view of a part of example of composition of a mechanism used for changing.

FIG. 5 is a diagram showing a recording trace pattern recorded and formed on a magnetic tape by a reciprocating recording and reproducing operation.

FIG. 6 is a diagram of a signal array used for describing a recording operation during an inversion period.

FIG. 7 is a diagram showing a recording trace pattern formed on a magnetic tape by a recording operation during a reversal period.

FIG. 8 is a diagram of a signal array used for describing a reproduction operation during an inversion period.

FIG. 9 is a diagram of a signal array used for describing a reproduction operation during an inversion period.

FIG. 10 is a diagram for explaining a track pattern.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input terminal of the signal to be recorded, 2 ... Output terminal of a reproduction signal, 3 ... Signal processing unit of recording system and reproduction system, 4 ...
Control head, 5: main control unit, 6: drum control unit, 7: drum motor, 8: drum inclination control unit, 9: capstan motor, 10, 11: signal generator, 12: center axis of drum structure DA, 14 ... tilt drive motor, 15,
16: a speed reduction mechanism comprising a plurality of gears, 17: a rotary encoder, 18: a position detector (preset sensor), 2
0 to 23: fulcrum, 30: capstan, 31: pinch roller, 32: control system (capstan control system) for running speed and running phase of magnetic tape, 33: frequency divider, 34 ...
Frequency-voltage converter, 35 ... adder, 36 ... drive circuit,
37, 41: recording / playback switch, 38: memory, 39 ...
Timing generator, 40... Path changeover switch, 42.
Recording / reproducing signal processing unit, DB: drum base, T: magnetic tape, DA: drum structure, Du: upper drum, Dd: lower drum, Lr: lead ring, G: lead ring guide, H1 to H4: rotating magnetism Head, Te ... magnetic tape T
Reference edge,

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[Procedure amendment]

[Submission date] June 8, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

As described above, a running magnetic tape is helically scanned by a rotary magnetic head, so that analog signals can be recorded and reproduced on a magnetic tape by azimuth.
TR (VCR) is a V for recording and reproducing analog signals.
In addition to being widely used worldwide as HS (registered trademark) home VCRs (VCRs), home digital VTRs (VCRs) that enable azimuth recording and reproduction of digital data on magnetic tapes are also available worldwide. DVC standards established as a result of discussions at the "HD Digital VCR Council", in which many VTR-related manufacturers and laboratories from various countries participated, include discrete cosine transform (DCT), adaptive quantization, and variable-length coding. High-efficiency compression of image information by various techniques such as
High-efficiency compression mode, recording data configuration mode, predetermined tape pattern, physical characteristics of the magnetic tape, cassette configuration mode to be applied when recording and reproducing on a magnetic tape as a D mode signal or an HD mode signal, And so on, and its practical use is being promoted. In the helical scan type magnetic recording / reproducing apparatus described above, the position of the rotation locus of the rotary magnetic head drawn in the space by the rotary magnetic head is under the condition that the tilt angle of the rotary shaft of the rotary magnetic head does not change. Is always constant.

Claims (2)

[Claims] 1. First and second magnetic air gaps having the same azimuth angle and provided at 180-degree symmetric positions on an upper drum.
With the rotary magnetic head, sequential recording marks are recorded and formed on the magnetic tape running in the forward direction, with an unrecorded area having a width of one recording mark being separated.
Third and fourth rotating magnetic heads having magnetic gaps having an azimuth angle different from the azimuth angle of the magnetic gap of the first and second rotating magnetic heads provided at the positions symmetrical with 80 degrees and having the same azimuth angle. As a result, on the magnetic tape running in the opposite direction, the first and second rotating magnetic heads are formed on the magnetic tape during the recording operation.
A magnetic tape running control means for running the magnetic tape, and a rotation locus of each rotary magnetic head and a reference edge of the magnetic tape so that sequential recording marks are recorded and formed in the unrecorded area of the recording mark width. The angle made is the order in which the magnetic tape runs,
In either case, in a helical scan type magnetic recording / reproducing apparatus provided with means for controlling the same angle at a predetermined time, a predetermined time set for a reversal operation of the traveling direction of the magnetic tape is set. As for the input information signal in the long tape inversion period, the signal of the time length corresponding to one recording trace period on the magnetic tape is used as the unit information signal, and the information signal of the sequential unit serially arranged on the time axis is used. Means for intermittently storing every other unit of information signal in the memory; signal switching means for switching and outputting the input information signal and the information signal read from the memory; At the point in time when the tape is running at a predetermined running speed and the recording operation is restarted, the information signal read from the memory by the signal switching means is output. Means for allowing the input information signal to be used as a recording signal by the signal switching means after a lapse of a predetermined time from the point at which the recording operation is resumed. Magnetic recording and reproducing apparatus. 2. A magnetic tape wound around a part of a peripheral surface of a drum composed of an upper drum and a lower drum is run at a predetermined running speed, and recording is performed by a rotating magnetic head attached to the upper drum. In the helical scan type magnetic recording / reproducing apparatus which performs the recording / reproducing operation of the information signal targeted for the above, the azimuth angle is set to a predetermined angle of 90 degrees or less clockwise with respect to the width direction of the recording trace. A first rotating magnetic head having a magnetic air gap,
And a second rotating magnetic head having a magnetic gap with the same azimuth angle are disposed on the upper drum at the same mounting height and 180 degrees symmetric with respect to the center axis of the drum. And a third rotating magnetic head having a magnetic gap whose azimuth angle is set to a predetermined angle of 90 degrees or less counterclockwise with respect to the width direction of the recording mark, The recording head is provided at a mounting height such that recording marks adjacent to the recording marks recorded on the magnetic tape by the head can be formed.
A fourth rotating magnetic head having a magnetic air gap of the same azimuth angle as the rotating magnetic head of No. 1 is rotated 180 ° with respect to the center axis of the drum 180 relative to the third rotating magnetic head.
Means for rotating an upper drum provided at the same mounting height as the mounting height of the third rotating magnetic head at a symmetrical position at a specific rotation speed only in a predetermined specific rotation direction; Means for controlling the angle between the rotation trajectory of each rotary magnetic head and the reference edge of the magnetic tape to be the same predetermined angle regardless of whether the running direction of the magnetic tape is the forward direction or the reverse direction; and Are running in one specific direction, the first (or third) rotating magnetic head and the second (or fourth) rotating magnetic head successively record and form on the magnetic tape. At a predetermined traveling speed such that an unrecorded area having at least one recording trace width is formed between recording traces, and the magnetic tape is moved in the predetermined traveling direction in a direction opposite to the specific one direction. Run at speed In the state where the magnetic tape is running, the first (or third) rotating magnetic head and the second (or fourth) rotating magnetic head sequentially record while the magnetic tape is traveling in the above-described specific direction. A third (or first) rotating magnetic head and a fourth rotating magnetic head are positioned at a position of an unrecorded area of at least one recording mark width formed between adjacent recording marks formed.
Means for running the magnetic tape at a predetermined running speed and running phase such that sequential recording marks are formed by the (or second) rotating magnetic head, and a means for reversing the running direction of the magnetic tape in advance. With respect to the input information signal in the tape reversal period of the set predetermined time length, the signal of the time length corresponding to one recording trace period on the magnetic tape is used as a unit information signal, and the information information signals are sequentially arranged in series on the time axis. Means for intermittently storing every other unit information signal in the unit information signal in the memory; signal switching means for switching and outputting the input information signal and the information signal read from the memory; When the recording operation is restarted after the magnetic tape is running at a predetermined running speed after the reversal, the signal is read from the memory by the signal switching means. Together to be used to broadcast signals as a recording signal by the signal switching means from the time of resumption of the recording operation described above after a predetermined period of time,
Means for allowing an input information signal to be used as a recording signal.