JPH11219553A - Magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a helically scanning magnetic recording/reproducing device capable of correcting the curve of a track. SOLUTION: A tape guiding surface 12 having the length in the width direction of a magnetic tape T longer than the width of the magnetic tape and also having the outer peripheral curved surface with the high middle part in which the radius of the center part in the width direction of magnetic tape T is larger than the redius of the both ends, is furnished as a guide pole GP individually arranged in the running path to the peripheral surface of a rum at the start side of winding and the end side of winding and also a structural mode in which at least a lower flange 7 is provided at the lower end of the tape guiding surface 12, is used. At the time of unloading operation, the height of the guide pole GP is controlled so that the upper surface of the lower flange 7 is positioned in the vicinity of the lower edge of the magnetic tape T and when the loading operation is finished and the running of magnetic tape T is started, the height of the guide pole GP is controlled so that the upper surface of the lower flange 7 is separated away from the lower edge of the magnetic tape T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic recording / reproducing apparatus,
In particular, a magnetic coil wound around a part of the drum peripheral surface by a rotating magnetic head provided so that a rotational trajectory surface is formed at a predetermined position with respect to a fixed portion of the body of the magnetic recording / reproducing apparatus. Recording and playback operations are performed on the tape,
The first and second guide poles which are individually arranged on the running path between the winding start side and the winding end side of the magnetic tape to be wound around a part of the drum circumferential surface described above. The height of the recording trace at the position near the first guide pole obtained based on the reproduction signal from the magnetic tape, and the bending information of the recording trace at the position near the second guide pole. Information about the height of the guide pole so that the closed loop automatic control operation of adjusting the recording trace of the magnetic tape to the rotation locus of the rotating magnetic head is performed by changing the height control signal generated using The present invention relates to a magnetic recording / reproducing apparatus including a generating unit and a height control mechanism including a driving source and a power transmission mechanism provided on a fixed portion of a body of the magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art A magnetic tape wound around a part of a peripheral surface of a drum is run at a predetermined running speed, and a specific recording trace pattern (track pattern) corresponding to the rotation locus of a rotary magnetic head is obtained. ) Is formed on a magnetic tape to perform a recording / reproducing operation, and is widely used as a video tape recorder (VTR) or a video cassette recorder (VCR). The above-mentioned track pattern has a specific format for each magnetic recording / reproducing method employed in the magnetic recording / reproducing apparatus, but is formed to operate according to the same magnetic recording / reproducing method. Even if the magnetic recording / reproducing device of the same standard exists, due to the variation due to the existence of the allowable manufacturing error, and other causes,
Generally, the track patterns formed on the magnetic tape corresponding to the rotation locus of the rotary magnetic head for each magnetic recording / reproducing device are different from each other.

[0003] For the above-mentioned reasons, the track pattern formed on the magnetic tape is different for each magnetic recording / reproducing device. Therefore, the recorded magnetic tape recorded by the magnetic recording / reproducing device is used for recording. When recording / reproducing is performed by a magnetic recording / reproducing apparatus other than the magnetic recording / reproducing apparatus (during compatible recording / reproducing operation), good reproducing operation may not be performed. In particular, when a track pattern is formed by recording traces having a narrow recording trace width (track width) for high-density recording, serious trouble may occur during the compatible recording / reproducing operation.

For example, in recent years, by recording three recording traces having a recording trace width of 19 μm on a magnetic tape T simultaneously in parallel, it has become possible to record and reproduce so-called high-vision image information. New form of VTR
(A so-called W-VHS VTR) has been proposed. In the above-described VTR of the new type, two adjacent recording marks among three recording marks formed in parallel on the magnetic tape T at the same time. Are used for recording / reproducing a video signal by two rotating magnetic heads having azimuth angles in opposite directions, and the remaining one recording trace is used for recording an acoustic signal by another rotating magnetic head. Used for reproduction,
The after-recording is also made possible by the rotary magnetic head for recording and reproducing the acoustic signal.

[0005] Incidentally, since the allowable value of the bending in one recording mark in the above-mentioned VTR is set to about 7 μm, for example, when after-recording is performed by the compatible recording / reproducing operation, the recorded magnetic tape is not recorded. A maximum of 1 between the recording trace and the rotation locus of the rotating magnetic head
A shift of about 4 μm may occur. So now,
Considering the case where the displacement of 14 μm occurs between the recording trace of the recorded magnetic tape and the rotation locus of the rotary magnetic head as described above, in the above case, the recording trace of the acoustic signal on the recorded magnetic tape is considered. The rotary magnetic head for recording and reproducing the audio signal to be subjected to the after-recording is shifted from the recording track for recording the audio signal on the recorded magnetic tape by 14 μm toward the recording track for recording the video signal adjacent thereto. In addition, a portion having a width of 14 μm in a recording trace for recording a video signal having a recording trace width of 19 μm is overwritten by an audio signal for after recording, and as a recording portion of an original video signal, Only the portion having a width of 5 μm is left, and the quality of the reproduced video signal is degraded.

In order to solve the above-mentioned problems, it is only necessary to match the rotation trajectory of the rotary magnetic head with the recording trace of the magnetic tape T. Conventionally, in the open loop control circuit or the closed loop control circuit, The rotating magnetic head is tracked to the recording trace of the magnetic head by being driven and displaced by a magnetic head driving device configured using an electro-mechanical conversion element (for example, a voice coil motor, a bimorph of an electrostrictive element) used as an actuator. Let them do it. For example, as disclosed in Japanese Utility Model Publication No. 63-34126 and Japanese Utility Model Application Publication No. Sho 61-158633, the rotating drum on which the rotating magnetic head is mounted and the lower drum are integrally tilted so that the rotating head becomes magnetic. The recording trace of the tape T can be tracked. For example, JP-A-60-1
As disclosed in JP-A-15043, the height of the guide pole is changed by the stacked piezoelectric elements.
For example, as disclosed in Japanese Utility Model Laid-Open Publication No. 61-153151, a gear is fixed to a shaft of a guide pole having a thread portion, and the gear is rotated by a motor to change the height of the guide pole. Various solutions have been proposed.

However, since about two rotary magnetic heads can be mounted on a single magnetic head drive device having a small size, it is used, for example, for recording and reproducing acoustic signals by a so-called deep recording method. In addition, it is difficult to mount an audio head on the magnetic head drive device, and the magnetic head drive device is very expensive. However, it is difficult to use it for consumer VTRs that require the.
Further, the rotating head and the lower drum are integrally tilted as in the above-described solution, and the rotating head is moved by the magnetic tape T.
In the magnetic recording / reproducing apparatus which is capable of tracking the recording marks of the magnetic recording / reproducing apparatus, it is possible to perform the tilt correction satisfactorily, but it is difficult to perform the bending correction. The element is not practical because it can only obtain a displacement of a few microns with a driving voltage of several hundred volts, and it is not practical to provide a motor or a gear on a pole base that is moved at the time of loading operation. There was a problem that it was extremely difficult.

[0008] The applicant's company has proposed a magnetic recording / reproducing apparatus as disclosed in Japanese Patent Application Laid-Open No. 7-57351, ie, a magnetic recording / reproducing apparatus, which does not cause the above-mentioned problems in the conventional apparatus. Recording and recording on a magnetic tape wound around a part of the drum peripheral surface by a rotary magnetic head provided so that a rotational trajectory surface is formed at a predetermined position with respect to a fixed portion of the body of the reproducing apparatus. A reproducing operation is performed, and the magnetic tape to be wound around a part of the drum peripheral surface is separately provided on a traveling path between a winding start side and a winding end side around the drum peripheral surface. A screw provided on the shaft of the guide pole is screwed into a screw hole threaded on the pole base of the loading mechanism to be disposed, and the structure integrated with the lower flange of the guide pole is formed. The height of the guide pole can be changed when a rotational force is transmitted to a gear of the magnetic recording / reproducing apparatus from a driving source provided in a fixed portion of the magnetic recording / reproducing apparatus via a power transmission system using the gear. The first,
The height of the second guide pole is determined based on the reproduction signal from the magnetic tape. The information on the curvature of the recording trace at a position near the first guide pole and the information at the position near the second guide pole are obtained. A reference position sensor and a rotary encoder that generate information on the height of the guide pole and a body of the magnetic recording / reproducing device are configured to be able to be changed by a height control signal generated using the bending information of the recording trace. By a closed loop automatic control system including a drive source and a power transmission mechanism provided in the fixed portion, an operation is performed such that the recording trace of the magnetic tape is adjusted to the rotation locus of the rotating magnetic head. A magnetic recording / reproducing apparatus having the height control mechanism configured as described above, and other magnetic recording / reproducing apparatuses (for example, Japanese Patent Application No. 9-120152). It is proposed.

[0009]

By the way, in the above-mentioned proposed magnetic recording / reproducing apparatus, the height is controlled by a height control signal generated by using the bending information of the recording trace obtained based on the reproduction signal from the magnetic tape. The first and second guide poles, which are variable in height, are provided so as to have an interval exactly equal to the width of the magnetic tape. The position of the lower edge is regulated. Therefore, when the magnetic tape used for the recording / reproducing operation in the magnetic recording / reproducing apparatus is thin as a base material, when the guide pole is vertically displaced by the height control, The lower flange may damage the edge of the magnetic tape.

The above-mentioned problem is caused by the problem that the first and second guide poles have a drum-shaped tape guide (crown) which does not have a flange for regulating a tape edge as disclosed in, for example, JP-A-3-73455. Roller). However, when a drum-shaped tape guide (crown roller) having no flange for regulating the tape edge is used, the tension of the magnetic tape may be loosened during the loading operation or the unloading operation. If so, the magnetic tape slips off the tape guide. Therefore, even when the tension of the magnetic tape is loosened, if the lower flange is provided so that the magnetic tape does not slip down from the tape guide, the above-described phenomenon can be prevented,
During loading operation or unloading operation,
If the lower flange is at a lower position than the lower edge of the magnetic tape, there is a problem that the magnetic tape is lowered too much and the magnetic tape is damaged.

[0011]

SUMMARY OF THE INVENTION According to the present invention, there is provided a magnetic recording / reproducing apparatus in which a rotating magnetic head is provided so that a rotational trajectory surface is formed at a predetermined position with respect to a fixed portion of a body of a magnetic recording / reproducing apparatus. The recording and reproduction operations are performed on the magnetic tape wound on a part of the drum, and the start and end of the winding on the drum peripheral surface of the magnetic tape to be wound on a part of the drum peripheral surface described above are determined. Information on the curvature of the recording trace at a position close to the first guide pole obtained based on the height of the first and second guide poles individually arranged in the traveling path of the magnetic tape based on the reproduction signal from the magnetic tape. And a height control signal generated using the bending information of the recording trace at a position close to the second guide pole to adjust the recording trace of the magnetic tape to the rotation locus of the rotary magnetic head. Closed loop As automatic control operation is performed,
A height control mechanism including a reference position sensor and a rotary encoder for generating information on the height of the guide pole, and a drive source and a power transmission mechanism provided on a fixed portion of a body of the magnetic recording / reproducing apparatus; In the magnetic recording / reproducing apparatus, the first and second guide poles are such that the length in the width direction of the magnetic tape is larger than the width of the magnetic tape, and the radius of the central part in the width direction of the magnetic tape is Is provided with a tape guide surface having an outer peripheral surface of a middle and high curved surface larger than the radii of both ends, and at least a lower flange is provided at a lower end of the tape guide surface. ,
The height of the second guide poles is controlled so that the upper surfaces of the lower flanges are located near the lower edge of the magnetic tape during unloading, and the loading operation is completed and the magnetic tape starts running. Sometimes, there is provided a magnetic recording / reproducing apparatus provided with means for controlling the height of the first and second guide poles so that the upper surfaces of the lower flanges are separated from the lower edge of the magnetic tape.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific contents of a magnetic recording / reproducing apparatus according to the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a perspective view of a magnetic recording and reproducing apparatus according to the present invention.
Is a drum base. The drum base DB is a component that is fixed to a fixed portion of the body of the magnetic recording / reproducing device and functions as a fixed portion of the body of the magnetic recording / reproducing device. Dd is a lower drum fixed to the drum base DB, and Du is an upper drum. The upper drum Du and the lower drum Dd constitute a drum structure DA. Md is a drum drive motor provided with the rotor fixed to the upper drum Du. In the following description, it is assumed that the upper drum Du is a rotating drum.

1 is a substrate, and 2 is a drum structure DA.
The center axis 2 is fixed to the center of the lower drum Dd fixed to the drum base DB.
The upper drum Du is rotatably mounted on the center shaft 2 of the drum structure MA via a bearing. 3,4
Is a screw for fixing the stator of the drum motor Md to the substrate 1. G is a gap between the upper drum Du and the lower drum Dd, and the rotary magnetic head H forms a rotation locus plane at a predetermined position with respect to a fixed portion of the body of the magnetic recording / reproducing apparatus. A required number of rotating magnetic heads H are used according to the magnetic recording / reproducing method applied to the magnetic recording / reproducing apparatus.

BC is a base catcher, and the base catcher BC is provided in the drum base DB. When the loading operation of the magnetic tape performed by the loading mechanism is completed, the magnetic tape T is wound in a predetermined range on the outer peripheral surface of the upper drum Du and the lower drum Dd constituting the drum structure DA. (FIG. 1 shows a state when the loading operation of the magnetic tape by the loading mechanism is completed).

During the loading operation, the loading mechanism pulls out a magnetic tape stored in a tape cassette (not shown) and, when the loading operation is completed, winds the magnetic tape around a part of the drum peripheral surface. Guide pole G placed in a running path on the side of the winding start of the magnetic tape around the drum peripheral surface
A first pole base PB provided with P and a slant pole (slant pole) SP is provided.

The loading mechanism cooperates with the first guide pole during the loading operation to pull out the magnetic tape housed in the tape cassette, and in a state where the loading operation is completed, A second guide pole provided in a state where the magnetic tape wound around a part of the drum peripheral surface is disposed on a traveling path on the end side of the drum peripheral surface and an inclined pole; Pole base PB. The first and second pole bases PB are fixed to, for example, a link constituting a loading mechanism, and are fixed by a guide rail (not shown) from the position of the tape cassette to the position of the drum structure DA. It is configured to be able to move along the moving path of the vehicle.

In the magnetic recording / reproducing apparatus shown in FIG. 1 in which the loading operation of the magnetic tape is completed by a loading mechanism (not shown), the upper drum Du and the lower drum D constituting the above-mentioned drum assembly DA are shown.
The first and second guide poles GP are provided with a guide pole GP wound with a magnetic tape and a pair of inclined poles SP in a predetermined range on a peripheral surface of the first and second magnetic tapes.
Each of the second pole bases PB has its tip end connected to an individual base catcher BC provided corresponding to each of the pole bases PB. Thereby, when the loading operation of the magnetic tape is completed by the loading mechanism, each of the first and second pole bases P
B is set in a state in which it is located at a spatial position having a predetermined positional relationship in all of the horizontal direction and the vertical direction with respect to the fixed portion of the body of the magnetic recording / reproducing apparatus.

As described above, the loading mechanism has the pole base P on which the guide pole GP and the inclined pole SP paired with the guide pole GP are provided.
B are provided. FIG. 1 shows one of the two pole bases, namely, a running path on the end side of the drum peripheral surface of the magnetic tape wound around a part of the drum peripheral surface when the loading operation is completed. Only the pole base PB on which the second guide pole disposed inside and the inclined pole are provided is shown, and the first guide pole and the pair of inclined poles are shown. Are not shown in the figure. This is because the pole base PB on which the first guide pole and the pair of inclined poles are provided is not shown in the drawing because it exists on the side opposite to the drum structure DA in the drawing.

By the way, the first guide pole height control mechanism and the second guide pole height control mechanism used in the magnetic recording / reproducing apparatus shown in FIG. The configuration is used. Therefore, in the following description of the present specification, in the state where the loading operation of the magnetic tape by the loading mechanism is completed, the traveling path on the end side of the winding of the drum peripheral surface of the magnetic tape wound around a part of the drum peripheral surface A pole base PB provided with a second guide pole placed at a predetermined position in the inside and a tilt pole paired with the second guide pole, and a mechanism for controlling the height of the second guide pole Is often described simply using terms such as the guide pole GP without distinction between the first guide pole and the second guide pole.

As shown in FIGS. 2 to 5 which are used for explaining a specific configuration example and operation of the guide pole GP used in the magnetic recording / reproducing apparatus shown in FIG. The guide pole GP used in the recording / reproducing apparatus has a length in the width direction of the magnetic tape T larger than the width of the magnetic tape, and a radius of the central portion in the width direction of the magnetic tape is larger than radii of both ends. Tape guide surface 12 having a middle and high curved outer peripheral surface (peripheral surface of guide roller 12)
And a configuration in which a lower flange 7 is provided at least at the lower end of the tape guide surface 12 described above. 2 to 4 show the tape guide surface 12.
A guide pole GP having a configuration in which flanges 7 and 11 are individually provided at both ends of the guide pole GP is shown, and FIG. 5 shows a configuration in which the flange 7 is provided only at the lower end of the tape guide surface 12. The guide pole GP is shown.

FIGS. 2A to 5A are top views of the pole base PB, and FIGS. 2C and 5C and FIGS. 3A and 3B are FIGS. Figure 2 above
FIG. 6 is a longitudinal sectional view taken along a line A to A in each of FIGS. Each of FIGS. 2 and 5 (b) shows a hole 13 that fits into the tip 5a of the shaft 5 of the guide pole GP.
FIG. 6 is a perspective view of a light-shielding plate 13 including a mounting portion 13a having b. The light shielding plate 13 is a member that constitutes the position detector PS together with the photo interrupter 24 shown in FIGS. The semicircular light-shielding plate 13 used as a constituent member of the position sensor PS includes:
The height of the guide pole GP is adjusted as described later so as to have a predetermined mounting phase so that the position detecting operation of the height position can be performed satisfactorily. Are fitted and fixed.

2 to 5, reference numeral 5 denotes a shaft of a guide pole GP. The shaft 5 of the guide pole is inserted into a hole 6 formed in the pole base PB in the vicinity of the lowermost end thereof. The moving direction of the guide pole shaft 5 is guided by the hole 6. A lower flange 7 having a gear 7g formed on the lower outer periphery is fitted and fixed to the shaft 5 of the guide pole. Reference numeral 47 denotes a male screw formed on a part of the outer peripheral surface of the shaft 5 of the guide pole. 7g of the gear described above
Is a drive gear 22 (FIG. 1) of a height control mechanism provided on a fixed portion side of a body of a magnetic recording / reproducing apparatus described later.
This is a driven gear that rotates while meshing with.

A male screw 47 formed on a part of the outer peripheral surface of the shaft 5 of the guide pole is screwed into a female screw 8 provided on the standing portion 9 of the pole base PB. The length of the female screw 8 is equal to the length of the guide pole shaft 5.
When the shaft 5 of the guide pole is rotated, the guide pole GP is displaced in the direction of the center line of the shaft 5 because the guide pole GP is set in a range longer than the male screw 47 formed on a part of the outer peripheral surface of the guide pole. become.

In the guide pole GP shown in FIGS. 2 to 4, reference numeral 11 denotes an upper flange of the guide pole GP, and a magnetic tape is provided between the lower surface of the upper flange 11 and the upper surface of the lower flange 7. A roller 12 having a length greater than the width of the magnetic tape T is rotatably inserted into the shaft 5 of the guide pole. In the guide pole GP shown in FIG. 5, the length between the lower surface of the regulating member 48 at the upper end position of the roller 12 and the upper surface of the lower flange 7 is larger than the width of the magnetic tape T. Is rotatably inserted into the shaft 5 of the guide pole. The above-mentioned roller 12 is a so-called drum-shaped guide roller having a middle and high curved outer peripheral surface in which the radius of the central portion in the width direction of the magnetic tape is larger than the radii of both ends thereof.

In FIG. 1, Mg is a motor, and RE is a rotary encoder. As the rotary encoder RE, a rotary encoder having an appropriate configuration from among known various rotary encoders having a function of generating and outputting a pulse having information on the rotation direction of the rotation axis of the motor Mg and information on the rotation amount is provided. Is selected and used. The rotary encoder RE shown in each of the above-described drawings includes a motor Mg.
Are shown as being constituted by a light-shielding blade 16 and a photo-interrupter 17 attached to the rotary shaft 15. A gear 18 is fixed to the shaft 15 of the motor Mg in addition to the light-shielding blade plate 16 of the rotary encoder RE, and a gear 19 in a power transmission system is meshed with the gear 18.

Reference numeral 21 denotes a rotation shaft of the gear 19. A gear 20 is fixed to the rotating shaft 21, and the gear 20 is fixed to the gears 27, 28 fixed to the rotating shaft 29.
Of gears are meshed. The gear 28 is meshed with the gear 22 fixed to the rotating shaft 23. The gear 22 is a drive gear of a height control mechanism provided on the fixed portion side of the body of the magnetic recording / reproducing apparatus.

The operation of the loading mechanism (not shown) causes the pole base PB to move along the predetermined movement path from the position of the magnetic tape cassette to the position of the drum structure DA, and the loading operation of the magnetic tape by the loading mechanism is performed. In the completed state, when the tip of the pole base PB is positioned by engaging with the base catcher BC provided corresponding to the pole base PB, the pole base PB is placed on the pole base side. A gear 7g provided as a driven gear in the height control mechanism is meshed with a drive gear 22 of the height control mechanism provided on the fixed portion side of the body of the magnetic recording / reproducing apparatus.

FIGS. 7A to 7C illustrate the manner in which the reference position (the reference height position of the guide pole GP) is detected by the position sensor PS constituted by the light shielding plate 13 and the photo interrupter 24. FIG. In the figure, 25 is a light emitting element, and 26 is a light receiving element. In the illustrated example, the position sensor PS (see FIGS. 6 and 7 in FIG. 6) is configured to generate a position signal when the light shielding plate 13 enters and exits the optical path from the light emitting element 25 to the light receiving element 26. ).

The light shielding plate 13 is connected to the tip 5 of the shaft 5.
When the roller 12 is mounted on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) in the guide pole GP, the position of the largest diameter portion (the central portion of the roller 12 in the magnetic tape width direction) is When the magnetic recording / reproducing apparatus is at a predetermined regular height position for ensuring the recording / reproducing compatibility, the light shielding plate 13 of the position sensor PS is in the reference rotation position, that is, the photo interrupter. The position at the moment when the light from the light emitting element 25 is received by the light receiving element 26 out of the optical path between the light emitting element 25 and the light receiving element 26 disposed facing each other in [24] [FIG. (A), the hole 13b of the light shielding plate 13 made of an elastic material in the position sensor PS is press-fitted and attached to the tip 5a of the shaft 5 of the guide pole GP. .

By the way, the guide pole GP to which the light shielding plate 13 of the position sensor PS is attached as described above is used when the driven gear 7g is not meshed with the driving gear 22.
If a rotation force is applied thereto and the guide pole GP rotates, the guide pole GP may move upward and downward. Therefore, the light shielding plate of the position sensor PS corresponds to a state in which the guide surface of the guide pole GP is set at a predetermined regular height position with respect to the magnetic recording / reproducing apparatus in order to ensure recording / reproducing compatibility. After the guide pole GP is attached to the guide pole GP so that the reference pole 13 is at the reference rotation position, the guide pole GP is not affected by external force acting as a disturbance.
To prevent P from rotating, the male screw 47 formed on a part of the outer peripheral surface of the guide pole shaft 5 and the female screw 8 provided on the pole base PB are screwed without play using the spring 10. Preloaded to match.

Next, in FIG. 6 showing a schematic configuration of the magnetic recording / reproducing apparatus of the present invention, reference numeral 31 denotes an input terminal of an information signal to be recorded / reproduced in the magnetic recording / reproducing apparatus.
2 is an output terminal, and 33 is an external control input terminal. Also, H
Is a rotary magnetic head representatively representing a plurality of rotary magnetic heads mounted on the upper drum (Du in FIG. 1). Further, 34 is a recording / reproduction signal processing unit, 35 is an envelope detection unit, and 36 is a control unit. 37 and 40 are reference position sensors, 38 and 41 are rotary encoders, 3
Reference numerals 9 and 42 denote control motors (control motors 39 and 42 in FIG. 1).
, 43 is a drum control unit, 44 is a tape running control unit, 45 is a loading control unit, and 46 is an external nonvolatile memory and an external control input terminal.

A control input is supplied to the external control input terminal 33 from an operation unit (not shown). The magnetic recording / reproducing apparatus is configured such that the control unit 36 to which the external control input signal supplied to the external control input terminal 33 is supplied controls the operation state of each component of the apparatus, thereby providing the external control input signal. , The operation is performed in a predetermined operation mode. As the control unit 36, for example, a microprocessor, a read only memory (RO)
M), a random access memory (RAM), a counter (counter), an up-down counter and the like can be used.

When the magnetic recording / reproducing apparatus performs a recording operation, the information signal supplied to the input terminal 31 which is to be recorded / reproduced is converted by the recording / reproducing signal processing section 4 into a recording signal suitable for recording. When a magnetic recording / reproducing apparatus performs a reproducing operation, a reproduced signal reproduced from a recorded magnetic tape (not shown) by the rotating magnetic head H is recorded on the magnetic tape (see FIG. 1) by the rotating magnetic head H. After a predetermined signal processing is performed by the recording / reproducing signal processing section 4, a reproduction output signal is output from the output terminal 32. When the magnetic recording / reproducing apparatus is performing the reproducing operation, the reproduction frequency modulated wave signal is supplied from the recording / reproducing signal processing section 4 to the envelope detecting section 5 and is output from the envelope detecting section 5. The envelope signal is supplied to the control unit 36.

The above-mentioned envelope signal is used as bending information indicating a bending state of a recording mark formed on a recorded magnetic tape to be reproduced.
As described later, the height of the guide poles individually arranged in the traveling path between the winding start side and the winding end side on the drum peripheral surface,
It is used to make the recording trace coincide with the rotation trajectory of the rotary magnetic head by changing it by the automatic control operation of the closed loop automatic control system.

The control section 36 sends control data to the drum control section 36 to rotate a drum drive motor (indicated by a symbol Md in FIG. 1) at a predetermined rotation speed and a predetermined rotation phase. The unit 44 runs the magnetic tape at a predetermined running speed and running phase. Further, the control unit 36 controls the operation of the loading control unit 36. The reference position sensor 37, the rotary encoder 38, and the control motor 39 are components of a height control mechanism provided for controlling the height of the guide pole on the drum start side on the winding start side. The reference position sensor 40, the rotary encoder 41, and the control motor 42 are constituent members of a height control mechanism provided to control the height of the guide pole on the drum peripheral surface at the end of winding.

Now, a reference position sensor 37 (or 40) and a rotary encoder 38 (or 41) for generating information relating to the height of the guide pole, and a drive source [control The operation of the height control mechanism including the motor 39 (or 42)] and the power transmission mechanism is as follows. As described above, in the state where the loading operation by the loading mechanism is completed, the guide pole GP1 is installed at a predetermined position on the winding start side on the drum circumferential surface, and the guide pole GP2 is positioned on the winding end side on the drum circumferential surface. At a predetermined position, and the recorded magnetic tape T runs over the angular range of slightly more than 180 degrees (center angle of the drum) on the peripheral surfaces of the upper and lower drums to perform a reproducing operation. It is.

The recorded magnetic tape T used in the above-mentioned reproducing operation is in a state in which the sequential recording marks recorded on the magnetic tape T have no bend (for example, an alignment tape ...
Standard tape for adjustment), and a height position of the guide pole GP1 installed at a predetermined position on the winding start side on the drum peripheral surface, and a predetermined position on the winding end side on the drum peripheral surface. The height position based on the height position of the guide pole GP2 installed at the position, that is, the maximum diameter on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) in the guide pole GP. The position of the portion (the central portion of the roller 12 in the width direction of the magnetic tape) is
When the magnetic recording / reproducing apparatus matches a regular height position which is predetermined for ensuring recording / reproducing compatibility, the envelope of the frequency modulated wave signal reproduced from the rotating magnetic head H is It has a substantially rectangular shape.

However, the height of the guide pole GP1 installed at a predetermined position on the winding start side on the drum peripheral surface and the guide pole installed at a predetermined position on the winding end side on the drum peripheral surface are set. If the height position of the GP 2 is deviated from the reference height position, the recorded magnetic tape to be reproduced is sequentially recorded and formed on the magnetic tape as described above. Even if there is no bend in the recording trace, the envelope of the frequency-modulated wave signal reproduced from the rotating magnetic head is such that the height positions of the guide poles GP1 and GP2 are different from the normal height positions. Depending on the state of the shift, the wave changes.

If the recording mark formed on the recorded magnetic tape T has a bend, a guide pole provided at a predetermined position on the side of the winding start around the drum peripheral surface. A guide pole G installed at a height position of GP1 and a predetermined position on the end side of the winding around the drum peripheral surface.
When the height position of P2 coincides with the reference height position, the envelope of the frequency modulated wave signal reproduced from the rotating magnetic head H is in a state of changing in a wave shape. .

From the above, information on the bending near both ends of the recording trace is obtained in accordance with the change state of the envelope of the frequency modulated signal reproduced from the recorded magnetic tape T to be reproduced. Then, based on this, the height control signal of each guide pole is generated, and the operation of the closed loop automatic control system is performed so that the envelope of the frequency modulated signal reproduced from the rotating magnetic head becomes rectangular over the entire recording trace. It can be seen that by controlling the height of each guide pole, the recording trace of the magnetic tape can be adjusted to the rotation locus of the rotating magnetic head.

Incidentally, the position (height) of the guide surface of the guide pole GP is determined by the signal generated by the reference position sensor PS (37, 40) and the rotary encoder RE.
It is detected based on the pulse count output from (38, 41). That is, the reference position sensor P
The position at the moment when the light-shielding plate 13 in S is out of the optical path between the light-emitting element and the light-receiving element disposed opposite to the photointerrupter 24, and the light of the light-emitting element is received by the light-receiving element. Is defined as the reference rotation phase of the light shielding plate 13, and the height of the guide pole GP when the light shielding plate 13 is in the reference rotation phase is defined as the guide pole GP.
The reference position of the guide surface of
The amount of displacement in the downward direction (difference in height) is determined by the cumulative value of the number of pulses output from the rotary encoder RE between the reference position and the current position (for example, the number of pulses performed by an up / down counter). Is calculated by adding the upward displacement of the guide pole and subtracting the downward displacement of the guide pole).

The light shielding plate 13 of the above-described reference position sensor PS
The guide pole GP to which is attached is provided on the loading pole side meshed with the drive gear 22 of the power transmission system in the height control mechanism provided on the fixed portion side of the body of the magnetic recording / reproducing apparatus as described above. When the driven gear 7g of the moving height control mechanism is driven and rotated,
It is configured to be able to move up and down. For this purpose, the guide pole GP is configured such that the driven gear 7g is
2 and the guide pole GP
When any rotational force (rotational force acting as a disturbance) is applied to the guide pole GP, the guide pole GP moves upward and downward.

As described above, the position of the portion of the maximum diameter (the central portion of the roller 12 in the magnetic tape width direction) on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) in the guide pole GP is determined. The light shielding plate 13 of the reference position sensor PS is set to the reference rotation position when the magnetic recording / reproduction device is at a predetermined regular height position in order to ensure recording and reproduction compatibility. When the guide pole GP is rotated by one or more rotations, even if the light shielding plate 13 of the reference position sensor PS is in the reference rotation position, the reference position sensor in that state is attached to the guide pole GP. The turning position based on the light shielding plate 13 of the PS does not correspond to the height position of the guide surface of the guide pole GP.

Thus, the position of the portion of the maximum diameter (the central portion of the roller 12 in the magnetic tape width direction) on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) in the guide pole GP is determined by the compatibility of recording and reproduction. The guide pole GP is set so that the light shielding plate 13 of the reference position sensor PS is at a reference rotation position in correspondence with a state in which the magnetic recording / reproducing device is at a predetermined regular height position in order to ensure the performance. After being mounted on the guide pole GP, the guide pole GP is prevented from rotating even when an external force acting as a disturbance is applied to the guide pole GP, or the guide pole GP is rotated when an external force acting as a disturbance is applied to the guide pole GP. However, it is desired that rotation cannot be made more than one rotation, and the reference position sensor P
It is desired that the light shielding plate 13 of S can be easily attached to the state of the reference rotation position.

In the magnetic recording / reproducing apparatus shown in FIG. 1, the loading operation is completed, and the tip of the pole base PB engages with a base catcher BC provided corresponding to the pole base PB for positioning. After the driven gear 7g of the height control mechanism on the pole base side is engaged with the drive gear of the height control mechanism provided on the fixed part side of the body of the magnetic recording / reproducing apparatus, When the recording / reproducing operation is performed, the running path of the magnetic tape on the drum peripheral surface of the magnetic tape wound around a part of the drum peripheral surface is the running path of the magnetic tape on the drum start side on the drum peripheral surface. The height of the guide surface of the first guide pole disposed therein and the height of the guide surface of the second guide pole disposed in the running path of the magnetic tape at the end of winding of the drum peripheral surface are determined. It is as described above that can change by reduction.

Thus, when the loading operation of the magnetic tape by the loading mechanism is completed, the magnetic tape wound around a part of the drum peripheral surface is placed at a predetermined position in the running path on the side of the winding start side of the drum peripheral surface. A first guide pole in a closed state, and a second guide pole arranged in a predetermined position in a traveling path on the end side of the winding of the drum peripheral surface of the magnetic tape wound around a part of the drum peripheral surface. For each of the guide poles, the position of the largest diameter portion (central portion of the roller 12 in the magnetic tape width direction) on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) in the guide pole GP is determined by the magnetic field. The recording device is set to have a predetermined regular height in order to ensure compatibility of the recording / reproducing operation.

In the state where the magnetic recording / reproducing apparatus is in the reproducing mode, the portion of the first guide pole having the maximum diameter on the outer peripheral surface (magnetic tape guide surface) of the roller 12 (guide roller 12) (the roller 12). The position of the center portion in the width direction of the magnetic tape) is determined by a height control signal generated using the bending information of the recording trace at the position near the first guide pole obtained based on the reproduction signal from the magnetic tape. The maximum diameter portion (the center of the roller 12 in the width direction of the magnetic tape) of the roller 12 (guide roller 12) on the outer peripheral surface (magnetic tape guide surface) of the second guide pole is changed by the height control mechanism. Part), the recording mark at a position near the second guide pole obtained based on the reproduction signal from the magnetic tape. Is varied by the height of the control mechanism by the height control signal generated by using bend information,
If a control operation is performed to match the rotation trace of the rotary magnetic head with the recording trace of the magnetic tape, a good reproduction operation can be realized.

That is, in general, the curvature of a normal recording mark appearing on a recording mark of a recorded magnetic tape to be reproduced in a magnetic recording / reproducing apparatus is U-shaped or S-shaped. Now, for example, a recorded magnetic tape showing an S-shaped bend of a recording mark will be described as an example. In the magnetic tape wound around a part of the drum peripheral surface, the winding start side of the magnetic tape wound around the drum peripheral surface is described. The height of the guide surface of the first guide pole (the position of the magnetic tape running path) in a state where it is arranged at a predetermined position in the running path, and the drum in the magnetic tape wound around a part of the drum peripheral surface The height of the guide surface of the second guide pole (the position of the magnetic tape traveling path) in a state where it is arranged at a predetermined position in the traveling path on the winding end side of the peripheral surface,
Flip each other.

That is, when one of the guide poles is raised, the other is lowered. For example, the height can be corrected by changing the heights of the first and second guide poles in directions opposite to each other. A first guide pole disposed on a running path on the magnetic tape at a winding start side on a drum peripheral surface so that such correction is performed;
The height at which the control signal obtained based on the information of the recording trace bending is given to the height of the guide surface between the magnetic tape and the second guide pole arranged on the running path on the end side of the drum peripheral surface. With this control mechanism, it is possible to easily obtain a good reproduction signal free from the influence of the bending of the recording trace.

The state of the envelope of the reproduced frequency modulated wave signal obtained from the magnetic recording / reproducing apparatus in the reproducing mode is corrugated corresponding to the S-shaped curve of the recording trace. Then, after detecting the reproduced frequency modulated wave signal by the amplitude detector, for example, a signal portion near the head of the envelope signal corresponding to each one recording trace sequentially output from the amplitude detector, Sampling is performed at a time position such that a signal portion near the end and an intermediate signal portion can be extracted, and sampling is performed from a signal portion near the head in the envelope signal corresponding to each of the above-described sequential recording traces. And a magnitude for changing the height of a first guide pole disposed in the traveling path on the winding start side on the drum peripheral surface based on the extracted signal and the signal extracted from the intermediate signal portion. Generating a height control signal having a direction and
It is supplied to the control motor Mg (39) of the first guide pole height control mechanism.

Further, based on the signal sampled from the signal portion near the end and the signal extracted from the intermediate signal portion in the envelope signal corresponding to each of the recording traces in sequence, the drum peripheral surface is determined. Generates a height control signal having a magnitude and a direction for changing the height of the second guide pole disposed in the traveling path on the end side of the second guide pole, and transmitting the control signal to the second guide pole. Is supplied to the control motor Mg (42) of the height control mechanism.

The magnitude of the signal sampled from the intermediate signal portion in the envelope signal corresponding to the reproduction frequency modulated wave signal reproduced from one recording trace is determined by the first and second guides. Changing the height of the pole does not change much. The information on the change in height can be easily obtained by comparing successive sample values on the time axis at the same position in the reproduced frequency modulated wave signal and the corresponding envelope signal reproduced from one recording trace in sequence. The control signal having the above-mentioned height is obtained by the control unit 3.
6 generated.

In the control mechanism of each different height for changing the height of the first and second guide poles to which the drive signal corresponding to the height control signal generated as described above is supplied. The control motor Mg (39, 42) is driven in a forward (or reverse) direction in accordance with the signal by a drive signal corresponding to a height control signal having a magnitude and a direction individually supplied according to the signal. Rotate by an amount corresponding to the signal. The rotational force of the control motor Mg (39, 42) is transmitted to the drive gear 22 via a power transmission mechanism including the gear 18 fixed to the rotating shaft 15, and meshed with the drive gear 22. Transmitted to the driven gear 7g,
The driven gear 7g rotates in the forward (or reverse) direction. As a result, the guide pole GP is displaced in the direction of the center line of the guide pole shaft 5, so that the reference position of the magnetic tape guide surface provided on the guide pole shaft 5 depends on the amount of rotation of the driven gear 7g. Depending on
It will be displaced downward.

Next, the standard height of the guide pole GP at the time of manufacturing the magnetic recording / reproducing apparatus described above (regular height predetermined for ensuring compatibility of the recording / reproducing operation)
Will be described. First, the setting mode of the standard height of the guide pole GP at the time of factory shipment is as follows.
P is displaced upward and downward, and the guide pole G
The height of the reference position at P (the central portion of the roller 12 in the width direction of the magnetic tape) is determined in advance by a measuring device in order to ensure the compatibility of the recording / reproducing operation between the magnetic recording / reproducing devices. Is adjusted to a state where the normal height is set in the external nonvolatile memory 46 (see FIG. 1).
To memorize.

Alternatively, the guide pole GP is displaced upward and downward by driving the drive motor Mg so that the envelope of the reproduced frequency modulated wave signal obtained by reproducing the standard tape is flattened. The height of the reference position (the central portion of the roller 12 in the width direction of the magnetic tape) at the predetermined height (a predetermined predetermined height (for ensuring compatibility of recording and reproducing operations between magnetic recording and reproducing devices)) ), And the count value of the counter (counter) in the above state is stored in the external nonvolatile memory 46 (see FIG. 1).

The latter mode of setting the standard height of the guide pole GP at the time of factory shipment will be specifically described as follows. First, a standard tape (recorded magnetic tape having no bent recording traces) is mounted on the magnetic recording / reproducing apparatus, and the height of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface is increased. The control motor Mg (39 in FIG. 6) in the control mechanism is operated until the reference position sensor PS (37 in FIG. 6) outputs a reference position signal corresponding to the reference rotation position of the light shielding plate 13 until the reference position signal is output. Invert or reverse.

The control unit 36 first determines the reference position of the light shielding plate 13 from the reference position sensor PS (37 in FIG. 6) of the height control mechanism of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface. By the time the reference position signal corresponding to the rotational position of the rotary encoder RE is output, the rotary encoder RE
A counter (not shown) provided in the control unit 36 that has counted the number of pulses output from (38 in FIG. 6) is set in advance when the reference position signal is output. The preset value is preset to a predetermined numerical value (for example, zero).

Next, the control motor Mg (42 in FIG. 6) in the height control mechanism of the guide pole GP at the end of winding the standard tape on the drum peripheral surface mounted on the magnetic recording / reproducing apparatus is The light is rotated forward or backward until the reference position sensor PS (40 in FIG. 6) outputs a reference position signal corresponding to the reference rotation position of the light shielding plate 13. Next, in the control unit 36, the reference position sensor P in the height control mechanism of the guide pole GP at the end side of the winding of the magnetic tape around the drum peripheral surface is controlled.
The number of pulses output from the rotary encoder RE (41 in FIG. 6) from S (40 in FIG. 6) to the point in time when the reference position signal corresponding to the reference rotation position of the light shielding plate 13 is output. A counter (not shown) provided in the control unit 36 that counts the number of times is preset to a predetermined numerical value (for example, zero) when the reference position signal is output. .

Next, the reproduction operation is performed by running the standard tape, and after the running state becomes stable,
The reproduced frequency modulated wave signal is detected by the envelope detector 35 and supplied to the controller 36. Envelope detector 35
Then, sampling is performed at a time position such that a signal portion near the head, a signal portion near the end, and an intermediate signal portion can be extracted from the detected envelope signal corresponding to each one recording trace in sequence. Then, the sample value is converted from analog to digital, and given to the control unit 36.

In the control unit 36, first, the control motor Mg (39 in FIG. 6) in the height control mechanism of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface causes the magnetic tape to move to the drum peripheral surface. The envelope signal is detected while changing the height of the guide pole GP on the winding start side over the variable range thereof, and changes with the change in the height of the guide pole GP (change in the count value of the counter). The magnitude (envelope value) of the envelope signal is calculated, and it is sequentially stored in a memory (not shown) in the control unit 36.
Write to. Then, the control unit 36 reads each of the envelope values obtained over the variable range of the height from the memory and compares them, and the counter when the envelope value indicating the state of the highest flatness is obtained is obtained. Is written to the external nonvolatile memory 46.

Next, the control unit 36 controls the height of the guide pole GP on the ending side of the magnetic tape around the drum peripheral surface by the control motor Mg (42 in FIG. 6) in the height control mechanism. The envelope signal is detected while changing the height of the guide pole GP on the winding start side over the variable range thereof, and the envelope changes with the change in the height of the guide pole GP (count value of the counter). The magnitude (envelope value) of the signal is calculated, and it is sequentially written into the memory (not shown) in the control unit 36. Then, the control unit 36 reads each of the envelope values obtained over the variable range of the height from the memory and compares them, and the counter when the envelope value indicating the state of the highest flatness is obtained is obtained. Is written to the external nonvolatile memory 46.

As described above, the data of the reference height of the guide pole on the winding start side of the magnetic tape around the drum peripheral surface,
Each counter value individually written in the external nonvolatile memory as the data of the reference height of the guide pole GP on the winding end side is stored in each guide pole GP in the magnetic recording / reproducing apparatus.
(A regular height predetermined for ensuring compatibility of recording and reproducing operations). Therefore, at the time of the recording operation of the magnetic recording / reproducing apparatus, if the height position of each guide pole GP is set corresponding to the counter value written in the external nonvolatile memory 46, the height of each guide pole GP can be increased. The position is set to a predetermined regular height for ensuring compatibility of the recording / reproducing operation.

As described above, the guide pole GP used in the magnetic recording / reproducing apparatus of the present invention has an outer peripheral surface whose central portion is larger in diameter than both ends, that is, a so-called drum-shaped outer peripheral surface. Roller 1 whose surface functions as a guide surface for magnetic tape
2, and the roller 12 is configured such that the length in the width direction of the magnetic tape is larger than the width of the magnetic tape. by the way,
At the start of running of the magnetic tape, the so-called drum-shaped outer peripheral surface is in sliding contact with the roller 12 functioning as a guide surface of the magnetic tape, even if the portion at the center position in the tape width direction is displaced from the portion of the maximum diameter of the roller 12. The magnetic tape T running while
The center position in the tape width direction is automatically displaced on the guide surface (outer peripheral surface) of the roller 12 so as to automatically coincide with the maximum diameter portion of the roller 12. The magnetic tape T travels in a state in which the center position in the width direction of the magnetic tape T matches the maximum diameter portion of the roller 12.

The guide pole GP used in the magnetic recording / reproducing apparatus of the present invention is driven and displaced upward and downward by the operation of the height control mechanism. The magnetic tape T still travels in a state in which a portion at the center position in the tape width direction automatically coincides with a portion having the maximum diameter of the roller 12. Therefore, as the component for determining the reference position of the height of the guide pole GP used in the magnetic recording and reproducing apparatus of the present invention, for example, the maximum diameter of the roller 12 is used instead of adopting the position of the upper surface of the lower flange 7. The position of the portion may be adopted. In the guide pole GP used in the magnetic recording / reproducing apparatus of the present invention, the outer peripheral surface having a larger diameter at the center portion than the diameter at both ends, that is, a so-called drum-shaped outer peripheral surface functions as a guide surface for the magnetic tape. The roller 12 is configured such that the length in the width direction of the magnetic tape is larger than the width of the magnetic tape as described above, and the lower end of the roller 12 has a A lower flange 7 for preventing falling off is provided.

In the magnetic recording / reproducing apparatus of the present invention, the magnetic tape stored in the tape cassette (not shown) is pulled out during the loading operation by the loading mechanism, and the drum peripheral surface is removed when the loading operation is completed. First pole provided with a first guide pole GP and an inclined pole SP, which are arranged on a traveling path on the side of the winding start of the magnetic tape wound around the drum around the drum peripheral surface. In cooperation with the base PB and the first guide pole during the loading operation,
With the magnetic tape stored in the tape cassette pulled out and the loading operation completed,
A second guide pole provided in a state where the magnetic tape wound around a part of the drum peripheral surface is disposed on a traveling path on the end side of the drum peripheral surface and an inclined pole; The pole base PB is fixed to a link, for example, and is moved from a position of the tape cassette to a position of the drum structure DA along a predetermined moving path by a guide rail (not shown).

In the magnetic recording / reproducing apparatus of the present invention,
At the time of the loading operation, the lower edge of the magnetic tape T stored in the tape cassette (not shown) is supported on the upper surface of the lower flange 7 of the guide pole GP (see FIG. 3B). Each pole base PB
The height of the guide poles GP so that the magnetic tape T can be pulled out by the guide poles GP provided at each end, and each tip of each pole base PB corresponds to each of the pole bases PB. When the loading operation is completed and the magnetic tape T starts running after being connected to the individual base catchers BC provided, the lower edge of the magnetic tape T is separated from the upper surface of the lower flange 7. The control operation of the height of the guide pole GP for the state (see FIG. 4B) is performed.

That is, in the magnetic recording / reproducing apparatus of the present invention, the control unit 36 controls the rotary encoder RE before starting the loading operation of the magnetic tape T to be performed on the magnetic recording / reproducing apparatus prior to the recording / reproducing operation.
(38 in FIG. 6), a count value of a counter (counter) for counting pulses generated from the rotary encoder RE,
The count value of the counter (counter) for counting the pulses generated from (41 in FIG. 6) is stored in the external nonvolatile memory 46.
Guide pole GP on the winding start side of the magnetic tape around the drum so that the count value is higher by a predetermined height than the reference value corresponding to the reference height of the guide pole GP stored in the guide pole GP. Control motor Mg in height control mechanism
The control motor 39 (FIG. 6) and the control motor Mg (the control motor 42 of FIG. 6) in the height control mechanism of the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface are rotated forward or backward. In this manner, the count value of the counter is determined by the height of the guide pole GP at the beginning of winding of the magnetic tape around the drum surface and the height of the guide pole GP at the end of winding of the magnetic tape around the drum surface. However, a state in which the height of the magnetic tape T is higher than the reference height of the guide pole GP by a predetermined height [FIG. 3B in which the lower edge of the magnetic tape T is supported on the upper surface of the lower flange 7 of the guide pole GP. State as shown].

In a state where the loading operation of the magnetic tape T to the magnetic recording / reproducing apparatus is completed and the magnetic tape T starts to run, the control unit 36 outputs a pulse generated from the rotary encoder RE (38 in FIG. 6). The count value of the counter (counter) for counting and the count value of the counter (counter) for counting the pulses generated from the rotary encoder RE (41 in FIG. 6) are stored in the external nonvolatile memory 46. The control motor Mg in the height control mechanism of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface so as to be in the state of the count value corresponding to the reference height of the existing guide pole GP (control of FIG. Motor 39)
And the control motor Mg (the control motor 42 in FIG. 6) in the height control mechanism of the guide pole GP at the end of winding of the magnetic tape around the drum peripheral surface is controlled so as to rotate forward or reverse. The count value of the counter is such that the height of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface and the height of the guide pole GP on the ending side of the magnetic tape winding around the drum peripheral surface are equal to the above-described guide pole GP. The lower edge of the magnetic tape T is set to the reference
4 (see FIG. 4B).

After the magnetic recording / reproducing apparatus of the present invention has performed the loading operation of the magnetic tape, the control unit 36 counts the number of pulses generated by the rotary encoder RE (38 in FIG. 6). The guide pole GP on the end side of the winding of the magnetic tape around the drum peripheral surface is placed on the magnetic tape around the drum peripheral surface so as to match the count value stored in the external nonvolatile memory 46. The control is performed such that the control motor Mg (the control motor 39 in FIG. 6) in the height control mechanism of the guide pole GP on the winding end side is rotated forward or backward. When the count value of the above-mentioned counter matches the count value stored in the external non-volatile memory 46 for the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface, the control motor Mg (FIG. 39) is stopped.

In the control section 36, the count value of a counter (counter) for counting the pulses generated from the rotary encoder RE (41 in FIG. 6) is used as a guide for the end of winding of the magnetic tape around the drum peripheral surface. The control motor Mg in the height control mechanism of the guide pole GP on the end side of the winding of the magnetic tape around the drum surface is set so that the pole GP coincides with the count value stored in the external nonvolatile memory 46. (The control motor 42 in FIG. 6) is controlled to rotate forward or reverse. When the count value of the above-mentioned counter matches the count value stored in the external non-volatile memory 46 for the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface, the control motor Mg (FIG. 42) is stopped.

By the above-mentioned operation, the spatial position of the guide surface of the guide pole GP at the start of winding of the magnetic tape around the drum and the guide surface of the guide pole GP at the end of winding of the magnetic tape around the drum are determined. The spatial position corresponds to the standard height of each guide pole GP in the magnetic recording / reproducing apparatus (regular height predetermined for ensuring compatibility of recording / reproducing operations). Therefore, when the above operation is completed, the height position of each of the guide poles GP is set to a predetermined regular height for ensuring compatibility of the recording / reproducing operation. If a recording operation is performed in this state, a recorded magnetic tape that can be reproduced well by another magnetic recording / reproducing apparatus can be obtained.

Next, when a reproducing operation is performed on a recorded magnetic tape loaded to be reproduced, the envelope detection unit 35 detects the reproduced frequency modulated wave signal reproduced from the recorded magnetic tape.
, That is, the envelope detection unit 35 can extract a signal portion near the head, a signal portion near the end, and a signal portion in the middle of the envelope signal corresponding to each one recording trace in sequence. Envelope signal (bend information data) obtained by performing sampling at such a time position and converting the sample value from analog to digital
The control unit 36 provided with the control motor Mg (39 in FIG. 6) in the height control mechanism of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface and the magnetic tape to the drum peripheral surface The control motor Mg (42 in FIG. 6) in the height control mechanism of the guide pole GP on the winding end side is rotated in the forward and reverse directions, respectively.

The height control mechanism of the guide pole GP at the start of winding the magnetic tape around the drum peripheral surface and the height control mechanism of the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface have already been described. As described above, since the automatic height control systems are respectively configured, the height of the guide pole GP at the beginning of winding the magnetic tape around the drum peripheral surface and the height of the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface are described. The height of the guide pole GP means that the guide pole GP is displaced upward and downward so as to be able to correct the curvature of the recording mark recorded on the recorded magnetic tape, and is recorded on the recorded magnetic tape. Even if the recording trace has a bend, a good reproduction signal can be obtained as in the case of reproducing a recorded magnetic tape in a state where the recording trace has no bend.

In the magnetic recording / reproducing apparatus shown in FIG. 1, the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface is used.
And a reference position sensor PS (3 in FIG. 6) provided separately for the height control mechanism of the guide pole GP and the height control mechanism of the guide pole GP at the end of winding the magnetic tape around the drum peripheral surface.
7, 40), each light shielding plate 13 generates a reference position signal at a reference rotation position and supplies it to the control unit 36. In addition, the rotary encoder RE (3 in FIG. 6)
8, 41) is a control motor Mg (39, 42 in FIG. 6)
A pulse having information on the rotation direction and the amount of rotation of the rotation shaft 32 is generated and supplied to the control unit 36.

Further, the envelope detecting section 35 to which the reproduced frequency modulated signal reproduced from the recorded magnetic tape is supplied generates an envelope signal corresponding to the envelope of the reproduced frequency modulated signal, and sends it to the control section 36. To supply. The control unit 36 controls the height control mechanism of the guide pole GP on the winding start side of the magnetic tape around the drum peripheral surface and the height control mechanism of the guide pole GP on the end side of winding the magnetic tape around the drum peripheral surface. A height control mechanism that generates a height control signal for each predetermined guide pole and that is configured as a closed-loop automatic height control system, that is, a reference position sensor PS, a rotary encoder RE, a control motor Mg, Gear 7g, 18-20, 2
The control motor Mg (39, 42 in FIG. 6) in the height control mechanism configured as a closed loop automatic height control system including the control poles 7, 28, 22, the guide pole GP, and the control unit 36 is driven.

The reference height position of the guide surface of the guide pole GP is determined by a pulse generated from the rotary encoder RE belonging to the height control mechanism when a reference position signal is output from the reference position sensor PS. After the count value of the counting counter (up / down counter) is preset to a predetermined value, the above-described guide in a state where the height of the guide surface of the guide pole GP is adjusted so as to be the reference height. The count value of the counter that counts the number of pulses generated from the rotary encoder RE of the height control mechanism to which the pole belongs (the external nonvolatile memory 46
, The amount of change in the height (rotation amount) of the guide pole GP from the reference height position of the guide surface is indicated by the rotary encoder RE. And the count value of the counter at the reference height position of the guide surface of the guide pole GP (for each guide surface stored in the external nonvolatile memory 46). (Information on the reference height).

In the magnetic recording / reproducing apparatus illustrated in FIG. 1, the first and second values are used by using the count value of the counter.
The height of the second guide pole GP is set to the reference height with high accuracy by the automatic height control operation of the above-described height control mechanism, or the predetermined height required during the loading operation. , Or can be changed with high accuracy according to the detected envelope value.

[0078]

As apparent from the above description, the magnetic recording / reproducing apparatus of the present invention has a rotation locus plane formed at a predetermined position with respect to a fixed portion of the body of the magnetic recording / reproducing apparatus. The recording and reproducing operations on the magnetic tape wound around a part of the drum peripheral surface are performed by the rotating magnetic head provided as described above, and the magnetic tape to be wound around the part of the drum peripheral surface described above. The heights of the first and second guide poles individually arranged in the traveling path between the winding start side and the winding end side of the tape around the drum peripheral surface are obtained based on a reproduction signal from the magnetic tape. The bending information of the recording trace at a position close to the first guide pole and the second
A closed loop automatic control operation for adjusting the recording trace of the magnetic tape to the rotation locus of the rotating magnetic head by changing the height control signal generated by using the bending information of the recording trace at a position near the guide pole of the rotating magnetic head. As described above, a reference position sensor and a rotary encoder that generate information on the height of the guide pole, and a drive source and a power transmission mechanism provided on a fixed portion of the body of the magnetic recording / reproducing apparatus are provided. In the magnetic recording / reproducing apparatus having a control mechanism, the first and second guide poles have a length in the width direction of the magnetic tape larger than the width of the magnetic tape, and A tape guide surface having an outer peripheral surface of a middle and high curved surface in which the radius of the central portion is larger than the radii of both ends. The tape guide surface described above is provided with a lower flange at the lower end, and the heights of the first and second guide poles are adjusted so that the upper surfaces of the lower flanges are positioned below the magnetic tape during unloading. When the magnetic tape is started to run after the loading operation is completed, the height of the first and second guide poles is adjusted so that the upper surfaces of the lower flanges thereof are adjusted. By providing a means for controlling the magnetic tape so as to be separated from the lower edge thereof, the first and second guide poles which are individually arranged in the running path between the winding start side and the winding end side around the drum peripheral surface are provided. The height information is obtained based on the reproduction signal from the magnetic tape, and the bending information of the recording trace at a position close to the first guide pole and the second information.
The automatic control operation of a closed loop that adjusts the recording trace of the magnetic tape to the rotation locus of the rotating magnetic head by changing the height control signal generated by using the bending information of the recording trace at a position near the guide pole of the rotating magnetic head. When performing the operation, the edge of the magnetic tape is not damaged by the presence of the flange, and even if the magnetic tape is loosened during the loading operation, it does not fall off by the lower flange, According to the present invention, the above-mentioned conventional problems can be solved well.

[Brief description of the drawings]

FIG. 1 is a perspective view of a part of a magnetic recording / reproducing apparatus of the present invention in a state where a loading operation is completed.

FIG. 2 is a diagram for explaining a guide pole provided on a pole base.

FIG. 3 is a diagram for explaining a guide pole provided on a pole base.

FIG. 4 is a diagram for explaining a guide pole provided on a pole base.

FIG. 5 is a diagram for explaining a guide pole provided on a pole base.

FIG. 6 is a block diagram showing a schematic configuration of a magnetic recording / reproducing apparatus of the present invention.

FIG. 7 is a diagram for explaining the operation of the position sensor.

[Explanation of symbols]

DB: drum base, Dd: lower drum, Du: upper drum, H: rotary magnetic head, BC: base catcher,
DA: drum structure, PB: pole base, Md: drum drive motor, Mg, 39, 42: control motor, GP: guide pole, SP: inclined pole, T: magnetic tape, R
E, 38, 41 ... rotary encoder, PS, 37,
40: Reference position sensor, 5: Guide pole shaft,
7, lower flange, 7g driven gear, 10 spring, 11 upper flange, 12 roller, 13 light shielding plate,
Reference numeral 15 denotes a rotating shaft of the control motor Mg, 16 denotes a light-shielding blade forming a part of the rotary encoder RE, 22 denotes a driven gear, 24 denotes a photo interrupter, 34 denotes a recording / reproducing signal processing unit, 35 denotes an envelope detecting unit. 36 ... Control unit,
43: drum control unit, 44: tape running control unit, 45:
Loading control unit, 46 external non-volatile memory,

Claims (1)

[Claims] 1. A magnetic recording / reproducing apparatus, which is wound around a part of a drum peripheral surface by a rotary magnetic head provided so that a rotational trajectory surface is formed at a predetermined position with respect to a fixed portion of a body of a magnetic recording / reproducing apparatus. The recording and reproducing operations for the magnetic tape are performed, and the magnetic tape to be wound around a part of the drum peripheral surface is individually moved along the running path between the winding start side and the winding end side around the drum peripheral surface. The height of the first and second guide poles to be arranged is determined based on the bending information of the recording trace at a position close to the first guide pole obtained based on the reproduction signal from the magnetic tape, and the second and third guide poles. A closed loop automatic control operation for adjusting the recording trace of the magnetic tape to the rotation trajectory of the rotating magnetic head is performed by changing the height control signal generated by using the bending information of the recording trace at a position near the guide pole. Re As described above, a height including a reference position sensor and a rotary encoder for generating information on the height of the guide pole, and a drive source and a power transmission mechanism provided on a fixed portion of the body of the magnetic recording / reproducing apparatus. In the magnetic recording / reproducing apparatus having a control mechanism, as the first and second guide poles, the length in the width direction of the magnetic tape is larger than the width of the magnetic tape, and in the width direction of the magnetic tape, A tape having a tape guide surface having an outer peripheral surface of a middle and high curved surface having a radius of a central portion larger than the radii of both ends is used, and at least a lower flange is provided at a lower end of the tape guide surface, and a configuration is used, When unloading the first and second guide poles, the upper surfaces of the lower flanges are located near the lower edge of the magnetic tape. When the magnetic tape starts running after the loading operation is completed, the heights of the first and second guide poles are adjusted so that the upper surfaces of the lower flanges are positioned from the lower edge of the magnetic tape. A magnetic recording / reproducing apparatus provided with means for controlling so as to be separated.