JPH11213483A - Pole base assembly in magnetic recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pole base assembly preventing a guide pole from rotating more than one rotation. SOLUTION: A movable member 13 of a position sensor is mounted at a prescribed mounting phase with respect to a guide pole GP set to a reference height position. Then, a turning range restricting member 30 of the guide pole is fitted on the outer peripheral surface 7b of a boss part of a lower flange 7 for preventing the guide pole GP which is set at the reference height position, from rotating more than one rotation from this set state. The rotating range is restricted within one rotation by a protruding part 30a provided on the turning range restricting member 30 and a protruding part 9a provided on a pole base PB.

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, as disclosed in Japanese Patent Application Laid-Open No. 60-115043, the height of the guide pole is changed by the stacked piezoelectric elements. For example, Japanese Utility Model Showa 61-1531
As disclosed in Japanese Patent Publication No. 51, 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.

FIGS. 21 to 25 are diagrams for explaining the above-mentioned proposed magnetic recording / reproducing apparatus. 21 and 22, DB is a drum base, and the drum base DB is fixed to a fixed portion of the body of the magnetic recording / reproducing apparatus. The drum base DB is also a component that functions as a fixing part of the body of the magnetic recording / reproducing apparatus. 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. M
d 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.

Reference numeral 1 denotes a substrate, and 2 denotes 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. H is a rotating magnetic head that rotates at a predetermined rotation speed in the gap G between the upper drum Du and the lower drum Dd. The rotating 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 the rotating magnetic heads H are used according to the magnetic recording / reproducing method applied to the magnetic recording / reproducing apparatus.

Reference numeral BC denotes a base catcher, which 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 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. 22 shows a state when the loading operation of the magnetic tape by the loading mechanism is completed, but the magnetic tape is not shown). During the loading operation, the loading mechanism pulls out a magnetic tape housed in a tape cassette (not shown), and when the loading operation is completed, the magnetic tape wound around a part of the drum peripheral surface. A first pole base P provided with a first guide pole GP and an inclined pole (slant pole) SP arranged in a traveling path on the winding start side around the drum peripheral surface of the first pole base P
B 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 a state where the loading operation of the magnetic tape by the loading mechanism (not shown) is completed, the upper drum D constituting the above-mentioned drum structure DA is completed.
u and a guide pole G for winding a magnetic tape around a predetermined range on the peripheral surface of the lower drum Dd.
P and the first and second pole bases PB provided with the pair of inclined poles SP are separate base catchers BC whose tip portions are provided corresponding to the respective pole bases PB. Combine with Thereby, the first and second pole bases PB at the time of completion of the loading operation of the magnetic tape by the loading mechanism are predetermined with respect to the fixed portion of the body of the magnetic recording / reproducing apparatus in all of the left-right direction and the up-down direction. It is set in a state where it exists at a spatial position having the specified positional relationship.

As described above, the loading mechanism is provided with the pole base P provided with the guide pole GP and the inclined pole SP paired with the guide pole GP.
B are provided. 21 and FIG.
One of the pole bases, i.e., in a state where the loading operation is completed, a state in which the magnetic tape wound around a part of the drum peripheral surface is arranged on a traveling path on the end side of the drum peripheral surface of the drum peripheral surface. A second guide pole to be
Only the pole base PB provided with the inclined pole is shown, and the pole base PB provided with the first guide pole and the paired inclined pole is not shown. 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 each of the drawings are described below. The same 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.

In the magnetic recording / reproducing apparatus shown in FIGS. 21 and 22, an example of the configuration of a guide pole GP provided on a pole base PB together with an inclined pole SP is shown in FIG. A top view of the base PB, (b) is a longitudinal sectional view taken along the line AA in (a), and (c) is a longitudinal sectional view of a part of (b) in FIG. . In FIG. 23, reference numeral 5 denotes a shaft of a guide pole, and the shaft 5 of the guide pole is inserted into a hole 6 formed in the pole base PB near the lowermost end thereof. Thus, the moving direction of the guide pole shaft 5 is guided.

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 7a denotes a male screw formed on a part of the outer peripheral surface of the shaft 5 of the guide pole. The gear 7g is a driven gear that is rotated by meshing with a drive gear 22 (FIGS. 21 and 22) of a height control mechanism provided on a fixed portion side of a body of a magnetic recording / reproducing apparatus described later. is there. A male screw 7a formed on a part of the outer peripheral surface of the guide pole shaft 5 is screwed into a female screw 8 provided on the pole base PB. Since the length of the female screw 8 is set to be longer than the male screw 7a formed on a part of the outer peripheral surface of the shaft 5 of the guide pole, when the shaft 5 of the guide pole rotates, the guide The pole GP will be displaced in the direction of the center line of its shaft 5.

Reference numeral 11 denotes an upper flange of the guide pole GP. The upper flange 11 has a lower surface spaced from the upper surface of the lower flange 7 by a distance equal to the width of the magnetic tape. Fixed to the shaft 5 of the guide pole. A roller 12 is provided between the upper and lower flanges 7 and 11, and the roller 12 is rotatably inserted into the shaft 5 of the guide pole. On the upper end surface of the protruding portion 11a of the upper flange 11, a semicircular light-shielding plate 13 used as a constituent member of a position sensor PS described later performs a good position detection operation of the height position of the guide pole GP. The mounting is adjusted so as to have a predetermined mounting phase, which can be carried out, and is fixed by the screw 14. Reference numeral 24 denotes a photo interrupter in the position sensor PS that cooperates with the light shielding plate 13 described above.

In FIGS. 21 and 22, 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 drawings described above.
Is shown as being constituted by a light shielding blade 16 and a photo interrupter 17 attached to the rotating shaft 15 of the motor Mg. Shaft 1 of the above-mentioned motor Mg
A gear 18 is fixed to the gear 5 in addition to the light shielding blade 16 of the rotary encoder RE.
The gear 8 is meshed with a gear 19 in the power transmission system. 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 meshed with a 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 moving path from the position of the magnetic tape cassette to the position of the drum assembly 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 engagement with the base catcher BC provided corresponding to the pole base PB, the pole base PB is connected to the pole base PB. 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. FIG. 25 is a diagram for explaining a detection mode of a reference position (a reference height position of the guide pole GP) detected by the position sensor PS constituted by the light shielding plate 13 and the photo interrupter 24. The light emitting element 26 is a light receiving element. In the illustrated example, the light emitting element 25 is used.
The position sensor PS is configured to generate a position signal when the light shielding plate 13 enters and exits the optical path from the light receiving element 26 to the light receiving element 26.

Light shielding plate 1 in the position sensor PS described above.
3 is attached to the upper end surface of the protrusion 11a of the upper flange 11 in the guide pole GP as described above.
When mounting the upper flange 11 of the upper flange 11 of the light shielding plate 13 on the upper end surface, the guide surface of the guide pole GP (the upper surface of the lower flange 7 of the guide pole, the lower surface of the upper flange 11 of the guide pole, the lower surface of the guide pole) When the magnetic recording / reproducing apparatus is in a state where the roller surface is at a predetermined regular height for ensuring recording / reproducing compatibility, the light-shielding plate 13 of the position sensor PS is rotated by the reference rotation. The position, that is, the moment when the light from the light emitting element 25 is received by the light receiving element 26 when the light goes out of the optical path between the light emitting element 25 and the light receiving element 26 which are disposed opposite to each other in the photo interrupter 24 The light shielding plate 13 of the position sensor PS is attached to the upper end surface of the protruding portion 11a of the upper flange 11 by the screw 14 so that the position (see FIG. 25A) is reached.

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, for example, reference numeral 1 in FIG.
The male screw 7a 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 backlashed by using an elastic body (for example, a rubber ring) indicated by 0. A preload is applied so as to screw together in a state where there is no gap.

[Problems to be solved by the invention]

Further, in the state where the guide surface of the guide pole GP is located at a predetermined regular height position for ensuring the compatibility of recording and reproduction in the magnetic recording and reproducing apparatus, Photo interrupter 24
Light-emitting element 25 and light-receiving element 2
6 is attached to the upper end surface of the protruding portion 11a of the upper flange 11 by a screw 14 so that the light comes from the light path between the light emitting element 25 and the light receiving element 26. Shield plate 13 of position sensor PS
The same turning position as the reference turning position of the guide pole GP
Exists for each one rotation.

Then, the guide pole GP is moved from the state where the guide surface thereof is set at the above-mentioned regular height position to 1 °.
It is necessary that no more rotation be allowed. For this purpose, in the magnetic recording / reproducing apparatus that has been already proposed, as shown in FIG. The light blocking of the position sensor PS is performed by using the rotation stopping mechanism of the guide pole GP configured to be positioned on the rotation locus of the light shielding plate 13 attached to the upper end surface of the protrusion 11a of the flange 11 of the GP. The plate 13 was configured to be unable to rotate more than one rotation. FIG. 24A is a perspective view of a main part including a stopper, and FIGS. 24B and 24C are plan views illustrating the operation of the operation part 32a of the stopper 32 with respect to the light shielding plate 13 of the position sensor PS. FIG.

However, it is difficult to attach the guide pole GP rotation preventing mechanism having the above-described configuration before assembling the guide pole GP to the pole base PB, and the workability is poor. become. Further, when a rotational force is applied to the guide pole GP in a state in which the light shielding plate 13 is in contact with the operating portion 32a of the stopper 32, the light shielding plate 13 is moved to the upper end surface of the protrusion 11a of the flange 11 of the guide pole GP. Rotating on the light shielding plate 13
A problem arises that the mounting phase changes. The present invention provides a pole base assembly including a guide pole rotation range limiting member that functions as a rotation stopping mechanism for the guide pole GP without the above-described problems.

[0026]

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 such that a rotational trajectory surface is formed at a predetermined position with respect to a fixed portion of a body of a drum. The recording and reproducing operations are performed on the magnetic tape wound on a part of the surface, and the start and end ends of the magnetic tape to be wound on the part of the drum peripheral surface around the drum peripheral surface. In order to change the height of the first and second guide poles individually arranged in the traveling path so that the rotation locus of the rotary magnetic head coincides with the recording trace of the magnetic tape. The rotation range of the movable member in the position sensor used as a part of the component that generates information on the height of the guide pole, which should be given to the closed loop automatic control system, is set to the reference height position In order to limit the rotation to within one rotation of the guide pole, the movable member of the position sensor is mounted at a predetermined mounting phase with respect to the guide pole set at the reference height position, and is set at the reference height position described above. The guide pole, the rotation range limiting member of the guide pole to prevent from rotating more than one rotation from the above state,
A pole base assembly fitted and fixed to a component of a guide pole, and a pole base provided with a screw for screwing a screw provided on a shaft of the guide pole as a rotation range limiting member of the guide pole. And a convex portion and a concave portion fitted to the concave portion and the convex portion provided at a position symmetrical with respect to the shaft of the guide pole described above at 180 degrees, and an outer periphery of a boss portion of the lower flange of the guide pole. A pole base assembly having an inner peripheral surface fitted to a surface, and a pole base provided with a screw to which a screw provided on a shaft of the guide pole is screwed as a rotation range limiting member of the guide pole 1 with the shaft of the guide pole described above at the center of symmetry
An inner peripheral surface having a convex portion and a concave portion fitted to the concave portion and the convex portion provided at positions symmetrical with 80 degrees, and being fitted to the outer peripheral surface of the boss portion of the lower flange of the guide pole. And a pole base assembly configured using a rotation stop that meshes with the teeth of a driven gear that supplies rotational force to the shaft of the guide pole, and a rotation limit of the guide pole As a member, it has a convex portion or a concave portion which fits into a concave portion or a convex portion provided on a pole base provided with a screw into which a screw provided on a shaft of a guide pole is screwed, and a boss of a lower flange of the guide pole. A pole base assembly constituted by using an inner peripheral surface fitted to a part of an outer peripheral surface of the portion, and a guide pole as a guide pole rotation range limiting member Has a convex portion or concave portion fitted to the concave or convex portion screw provided on the shaft is provided on the pole base is provided with a threaded screw, and,
The guide pole has an inner peripheral surface fitted to a part of the outer peripheral surface of the boss portion of the lower flange, and a detent is provided which meshes with a tooth of a driven gear that supplies rotational force to the shaft of the guide pole. And a concave or convex portion provided on a pole base provided with a screw into which a screw provided on a shaft of a guide pole is screwed as a rotation range limiting member of the guide pole. A projection or a recess that fits into the guide pole, and an inner peripheral surface that fits into a part of the outer peripheral surface of the boss of the lower flange of the guide pole. A pole base assembly formed by using a driven gear for supplying a force, and a lower flange of the guide pole as a guide pole rotation range limiting member. A driven gear that has an inner peripheral surface fitted to the outer peripheral surface of the boss portion and that supplies a rotational force to the shaft of the guide pole is provided with a component that does not mesh with the drive gear. The movable member of the position sensor is mounted at a predetermined mounting phase with respect to the pole base assembly configured as described above, and the guide pole set at the reference height position, and the guide pole set at the reference height position described above. As a rotation range limiting member of the guide pole for preventing the rotation of the guide pole from rotating more than one rotation from the above state at the time of unloading, the other end of the elastic member having one end fixed to the pole base, A pole base assembly including a brake portion for resiliently pressing a component of the component other than the running path of the magnetic tape; The movable member of the position sensor is attached to the guide pole set at the predetermined height position at a predetermined mounting phase, and the guide pole set at the reference height position is unloaded from the above state at the time of unloading. The other end of the elastic member, one end of which is fixed to the pole base, serves as a rotation limiter of the guide pole for preventing the rotation of the guide pole beyond the rotation. The component part is configured as a brake part that resiliently presses and has an inner peripheral surface that fits on the outer peripheral surface of the boss portion of the lower flange of the guide pole, and supplies rotational force to the guide pole shaft Base assembly using a driven gear that has a component that does not mesh with the drive gear, and is set at a reference height position Attach the movable member of the position sensor to the given guide pole at a predetermined mounting phase, and do not rotate the guide pole set at the above-mentioned reference height position more than one rotation from the above state at the time of unloading. The other end of the elastic member, one end of which is fixed to the pole base, serves as a guide pole rotation range restricting member for resiliently moving the components of the guide pole other than the magnetic tape running path. And a component for releasing the braking operation of the brake portion by contacting a brake release member provided on the fixed portion of the aircraft at the end of the loading operation. A pole base assembly.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of a pole base assembly in a magnetic recording / reproducing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1 to 20 are views showing different embodiments of the pole base assembly in the magnetic recording / reproducing apparatus of the present invention. In each of the above-mentioned drawings, a pole base assembly PB including a tilt pole SP and a guide pole GP is indicated by a reference numeral PB in the magnetic recording / reproducing apparatus shown in FIGS. 21 and 22. It is the member which is done. By the way, FIGS. 21 and 2
In the conventional guide pole GP described with reference to FIG.
The light shielding plate 13 of the position sensor PS is attached to the flange 11 of the guide pole GP by using the screw 14, but the fixing means for attaching the light shielding plate 13 of the position sensor PS to the flange of the guide pole GP is as described above. When the screw 14 is used as described above, the screw hole is formed in the flange, so that the press-fitting of the upper flange and the shaft 5 of the guide pole cannot be taken, the screw tightening man-hour increases, or the head of the screw is raised. If a flat head screw is used in order to prevent the screw head from protruding or the head of the screw from protruding upward as described above, a manufacturing problem such as a need for a flattening process may occur. There is.

However, in the pole base assembly of the present invention shown in FIGS. 1 to 20, as the light shielding plate 13 of the above-described position sensor, the whole or at least the mounting portion 13a is made of an elastic material. . The elastic material is selected from various synthetic resin materials, various metals and the like. 13b is a light shielding plate 13 of the position sensor
Are pressed into the end 5a of the shaft 5 of the guide pole. In the pole base assembly of the present invention, by using an assembly made of an elastic material, mounting screws (FIG. 21) are used for mounting the light shielding plate 13 of the position sensor PS.
~ Guide pole GP without using 14) in FIG.
Therefore, the above-described problem in the conventional example does not occur.

FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG. 9, FIG.
Each figure (a) in each figure of FIG. 13, FIG. 16, FIG.
Pole base P with inclined pole SP and guide pole GP
FIG. 4 is a top view of a pole base assembly provided in B. Further, each of the drawings (b) in each of the above-described drawings is a vertical cross-sectional side view taken along the line AA in each of the above-mentioned (a) drawings, and each of the drawings (c) in each of the above-described drawings is a magnetic recording medium. The shaft 5 of the guide pole GP set in a state in which the guide surface of the guide pole GP is located at a predetermined regular height position for ensuring compatibility of recording and reproduction in the reproducing apparatus. The light of the light emitting element 25 is received at the end 5a from the optical path between the light emitting element 25 and the light receiving element 26, which are disposed opposite to each other in the photo interrupter 24 described above with reference to FIG. FIG. 10 is a diagram illustrating a state immediately before press-fitting a hole 13b of a light-shielding plate 13 made of an elastic material in the position sensor PS so as to be a position at a moment when light is received by an element 26.

FIGS. 1, 3, 5, 7, 9, 11, 13, and 13 (d) show the guide pole GP in the above (c). 1 in state
It is a figure which shows the state which set the rotation range limitation member of the guide pole which does not rotate more than rotation to the guide pole GP, and each figure (f) in each said figure shows the rotation of said guide pole. It is sectional drawing used for description of the structure of a range limiting member. Further, each of FIGS. 16 and 18 (d) shows a state in which the guide pole GP is set to a rotation range limiting member of the guide pole for preventing the guide pole GP in the unloaded state from rotating. FIG. 18 (f) is a diagram for explaining the released state of the operation of the rotation range limiting member of the guide pole, and FIG. It is sectional drawing used for description of the structure of the rotation range limitation member of a guide pole.

In the pole base assembly of the present invention shown in FIGS. 1 to 20, reference numeral 5 denotes a shaft of a guide pole, and the shaft 5 of the guide pole has its lower end near the pole base PB. The shaft 6 of the guide pole is guided by the hole 6 which is inserted into the bore 6. A driven gear 7g is formed on the shaft 5 of the guide pole in the pole base assembly of the present invention shown in FIGS. 1 to 8, and 11, 12 and 16 to 20. The lower flange 7 is fitted and fixed. In the pole base assembly of the present invention shown in FIGS. 9, 10 and 13 and 14, the lower flange 7 fixed to the guide pole shaft 5 and the driven gear 27
g is separate from the driven gear 27
g is fitted and fixed to the boss of the lower flange 7.

Reference numeral 28 denotes a male screw formed on the outer peripheral surface of a part of the shaft 5 of the guide pole.
Is screwed into a female screw 8 provided on a mounting portion 9 of a guide pole erected on the main body of the pole base PB. Since the length of the female screw 8 is set to be longer than the length of the male screw 28 formed on a part of the outer peripheral surface of the guide pole shaft 5, when the guide pole shaft 5 rotates, the guide The pole GP will be displaced in the direction of the center line of its shaft 5. 11 is an upper flange of the guide pole GP.
Is fixed to the guide pole shaft 5 so that the lower surface thereof is spaced from the upper surface of the lower flange 7 at an interval equal to the width of the magnetic tape.

12 is the upper and lower flanges 7, 11
The roller 12 is provided between the rollers, and the roller 12 is rotatably inserted into the shaft 5 of the guide pole. On the upper end surface of the protruding portion 11a of the upper flange 11, a semicircular light-shielding plate 13 used as a constituent member of the position sensor PS has a hole 13b, as described above, in which the hole 13b of the guide pole shaft 5 is formed. It is press-fitted and fixed to the end 5a. Reference numeral 29 denotes a spring wound around the shaft 5 of the above-described guide pole. The spring 29 is provided between the male screw 28 formed on the outer peripheral surface of a part of the shaft 5 of the guide pole and the guide pole installed upright on the main body of the pole base PB. This is for screwing the female screw 8 provided in the part 9 without play.

FIG. 1, FIG. 3, FIG. 5, FIG. 7, FIG. 9, FIG.
The pole base assembly shown in each of FIGS. 13, 16 and 18 has a magnetic tape to be wound around a part of the drum peripheral surface and a winding start side and a winding end around the drum peripheral surface. Among the first and second guide poles individually arranged in the traveling path with the side, the second guide pole arranged in the traveling path on the end side of the drum peripheral surface is provided. 1 shows the pole base assembly, but the configuration of the pole base assembly provided with the first guide pole disposed on the traveling path on the winding start side around the drum peripheral surface is also shown. ,
Except that the arrangement relationship between the inclined pole SP and the guide pole GP is different, it is the same as the pole base assembly shown in each figure (a) in each figure.

In the magnetic recording / reproducing apparatus constructed using the pole base assembly of the present invention, the pole base PB in FIG. 21 and FIG. This is a configuration in which the pole base assembly shown in FIGS. 9, 11, 13, 16, and 18 is changed to the pole base assembly shown in FIG. By the way, also in the magnetic recording / reproducing apparatus constituted by using the pole base assembly of the present invention, the pole base PB of the pole base assembly is moved by the operation of the loading mechanism (not shown) at the time of the loading operation. Is moved along the predetermined movement path from the position of the drum structure DA to the position of the drum structure DA.

In the state where the loading operation of the magnetic tape by the loading mechanism is completed, when the tip of the pole base PB is engaged with the base catcher BC to perform positioning on the pole base assembly side, the pole base The driven gear 7g (or driven gear 27g) of the height control mechanism on the assembly side is made to mesh with the drive gear 22 of the height control mechanism provided on the fixed part side of the body of the magnetic recording / reproducing apparatus. This is the same as the case of the conventional magnetic recording / reproducing apparatus described with reference to FIGS. 21 and 22.

In the pole base assembly of the present invention, the guide surface of the guide pole GP (the upper surface of the lower flange 7 of the guide pole and the lower surface of the upper flange 11 of the guide pole) is used for recording / reproducing on the magnetic recording / reproducing apparatus. In order to ensure compatibility, the state is adjusted to a state of a predetermined regular height position, and in this state, the edge of the light-shielding plate 13 of the position sensor PS faces the photointerrupter 24 described above. The position at the moment when the light from the light emitting element 25 is deviated from the optical path between the arranged light emitting element 25 and light receiving element 26 and the light from the light emitting element 25 is received by the light receiving element 26 (see FIG. 25A). Then, the light shielding plate 1 of the position sensor PS
3 is fixed to the shaft 5 of the guide pole,
A rotation range limiting member for preventing the guide pole GP from rotating more than one rotation from the above state is attached to the guide pole.

In the pole base assembly shown in FIG.
The above-mentioned rotation range limiting member for preventing the guide pole GP from rotating more than one rotation is shown in FIGS.
As clearly shown in (c) of the specific configuration, the protrusion 9a and the recess 9b projecting from the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB are described. A concave portion 30b loosely fitted to the convex portion 9a of the
b is provided at one end and an inner circumferential surface 30c fitted to the outer circumferential surface of the boss portion 7b of the lower flange 7 is provided. The member 30.

As shown in FIG. 2B, an annular rotation range limiting member 30 [see the perspective view of FIG. 2A] is used as a component of the pole base assembly shown in FIG. After the shaft 5 of the guide pole GP is inserted, the male screw 28 provided on the outer peripheral portion of the shaft 5 and the mounting portion 9 of the guide pole erected on the main body of the pole base PB are screwed. The female screw 8 is screwed together, and a protrusion 9 a protruding from an upper end of a mounting portion 9 of a guide pole erected on the main body of the pole base PB and an annular rotation range limiting member 30 are provided. The concave portion 30b is loosely fitted, and furthermore, a concave portion 9b provided at the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB, and a convex portion 30a provided on the annular rotation range limiting member 30. And loosely fit
As shown in FIG. 1B, an annular rotation range limiting member 30 is provided between the upper end of the guide pole mounting portion 9 erected on the main body of the pole base PB and the boss portion 7b of the lower flange 7. It is placed in the middle.

FIG. 1 (f) is a view showing B in FIG. 1 (b).
It is sectional drawing in the -B line position. In the state shown in FIG. 1B, the height position of the guide surface of the guide pole GP (the upper surface of the lower flange 7 of the guide pole and the lower surface of the upper flange 11 of the guide pole) is recorded for the magnetic recording / reproducing apparatus. Adjustment is made to a state of a predetermined regular height position in order to ensure reproduction compatibility. Then, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing device, FIG. In the state shown in FIG. 1, the light-shielding plate 13 of the position sensor PS shown in FIG. 1 (e) is brought into a state in which the edge thereof has the predetermined rotation phase described above. Then, the hole 13b provided in the base portion 13a of the light shielding plate 13 is pressed into the distal end portion 5a of the shaft 5 of the guide pole GP, and
3 is fixed to the shaft 5.

Further, as described above, the annular rotation range restricting member 30 is provided on the annular rotation range restricting member 30 with respect to the convex portion 9a and the concave portion 9b provided at the upper end of the guide pole mounting portion 9 in the pole base PB. Annular rotation range restricting member 30 in a state where the concave portion 30b and the convex portion 30a are loosely fitted.
Is moved in the direction of the shaft 5 of the guide pole without rotating in the circumferential direction, and the state shown in FIG. 1D, that is, the guide pole in the pole base PB The concave portion 30b provided on the annular rotation range limiting member 30 loosely fitted to the convex portion 9a provided at the upper end of the mounting portion 9 is separated from the convex portion 9a,
Further, a convex portion 30a provided on an annular rotation range limiting member 30 loosely fitted into a concave portion 9b provided at an upper end of the guide pole mounting portion 9 in the pole base PB.
However, in a state separated from the concave portion 9b, the inner peripheral surface 30c of the annular rotation range limiting member 30 is fitted to the outer peripheral surface of the boss portion 7b of the lower flange 7, and the annular rotation is restricted. The range limiting member 30 is connected and fixed to the guide pole GP. If knurling is applied to the outer peripheral surface of the boss portion 7b of the lower flange 7, the above-mentioned manner of fixing the both becomes even stronger.

As described above, the state in which the height of the guide surface of the guide pole GP is adjusted to the predetermined regular height for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. In the above, when the inner peripheral surface 30c of the annular rotation range restricting member 30 is fitted to the outer peripheral surface of the boss 7b of the lower flange 7, the recording / reproducing compatibility of the magnetic recording / reproducing apparatus is improved. The guide pole GP in a state where the height position of the guide surface is adjusted to a predetermined regular height position for securing is allowed to rotate only within one rotation from the above state. Will be.

That is, the guide pole GP is formed on one side surface of the convex portion 9a provided at the upper end of the guide pole mounting portion 9 of the pole base PB and the convex portion provided on the annular rotation range limiting member 30. From the state of FIG. 2C in which one side surface of the portion 30a is in contact, the other side surface of the convex portion 9a provided at the upper end of the mounting portion 9 of the guide pole and the annular rotation The above-described annular rotation range in a state where the rotation can be performed only within one rotation until reaching the state where the other side surface of the projection 30a provided on the range limiting member 30 is in contact. The restricting member 30 is mounted on the guide pole GP.

Next, in the pole base assembly shown in FIG. 3, the rotation range limiting member for preventing the guide pole GP from rotating more than one rotation is shown in FIG.
As shown in (c), a specific configuration is specified, and the side surface of the protrusion 9a protruding from the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB is brought into contact. A convex portion 31a having a side surface is provided at one end,
The lower flange 7 has an inner peripheral surface 31c fitted to a part of the outer peripheral surface of the boss portion 7b, and is configured as a semi-annular (annular part).

In the pole base assembly shown in FIG.
A semi-annular rotation range limiting member 31 [see FIG. 4 (c)] used as a component thereof is provided on the outer peripheral portion of the shaft 5 of the guide pole GP shown in FIG. 4 (a). FIG. 3 is a cross-sectional view of a state in which the provided male screw 28 and the female screw 8 screwed into the mounting portion 9 of the guide pole erected on the main body of the pole base PB are screwed. As shown in FIGS. 3 (c) and 3 (d) in FIGS. 3 (b) to 3 (d), the lower flange 7 is fitted and attached to a part of the outer peripheral surface of the boss 7b.

FIG. 3F is a cross-sectional view of a portion including a cross section of the convex portions 31a and 9a in FIG. 3D. In the state shown in FIG. 3B, the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus. Then, the height position of the guide surface of the guide pole GP is adjusted to a predetermined normal height position for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus in FIG. (C) When the state shown in the figure is set, the light-shielding plate 13 of the position sensor PS shown in FIG. In such a state, the hole 13b provided in the base 13a of the light shielding plate 13 is pressed into the tip 5a of the shaft 5 of the guide pole GP to fix the light shielding plate 13 to the shaft 5.

Then, in the above state, the inner peripheral surface 31c of the semi-annular turning range limiting member 31 is fitted to the outer peripheral surface of the boss 7b of the lower flange 7. If knurling is applied to the outer peripheral surface of the boss portion 7b of the lower flange 7, the above-mentioned manner of fixing both can be made strong.
As described above, when the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording and reproduction compatibility of the magnetic recording and reproducing device, When the inner peripheral surface 31c of the annular rotation range restricting member 31 is fitted on the outer peripheral surface of the boss 7b of the lower flange 7, the magnetic recording / reproducing device is predetermined in order to ensure recording / reproducing compatibility. The guide pole GP in a state in which the height position of the guide surface is adjusted to the regular height position that has been set is allowed to rotate only within one rotation from the above state.

That is, the guide pole GP is provided on one side surface of the convex portion 9a provided at the upper end of the guide pole mounting portion 9 of the pole base PB, and on the semicircular rotation range limiting member 31. From the state shown in FIG. 4B in which one side surface of the convex portion 31a is in contact with the convex portion 9a, the convex portion 9a provided at the upper end of the mounting portion 9 of the guide pole described above.
Of the convex portion 31a provided on the semi-annular rotation range limiting member 31 so that the rotation can be performed only within one rotation until the other side surface comes into contact with the other side surface of the projection 31a. In such a state, the semi-annular rotation range limiting member 31 is mounted on the guide pole GP.

The pole base assembly described above with reference to FIGS. 1 to 4 is provided with a guide pole at a predetermined regular height for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. In this configuration, the rotation range restricting member is fitted on the outer periphery of the boss 7b of the lower flange 7 in a state where the height position of the guide surface of the GP is adjusted. Therefore, when the outer peripheral surface of the boss portion 7b of the lower flange 7 and the inner surface of the rotation range limiting member are loosely fitted, or
For example, when the shaft of the guide pole GP is rotated by a strong driving force, the inner surface of the rotation range limiting member may slip on the outer peripheral surface of the boss portion 7b of the lower flange 7. is there.

The pole base assembly shown in FIGS. 5 to 20 shows an example of the configuration of the pole base assembly which does not have the above-mentioned disadvantages. First, in the pole base assembly shown in FIGS. 5 and 6, the rotation range restricting member for preventing the guide pole GP from rotating more than one rotation is shown in a specific configuration in FIGS. As clearly shown in b), the convex portion 30a having a side surface which comes into contact with the side surface of the convex portion 9a protruding from the upper end of the mounting portion 9 of the guide pole erected on the main body portion of the pole base PB is annular. Of the driven gear 7g provided at one end of the main body of the driven gear 7g and provided at the other end of the annular main body at the lower flange 7.
0g and the boss 7b of the lower flange 7
Is provided with an inner peripheral surface 30c fitted to the outer peripheral surface.

An annular rotation range limiting member 30 used as a component of the pole base assembly shown in FIG.
As shown in FIG. 6A, after the shaft 5 of the guide pole GP is inserted, the male screw 28 provided on the outer peripheral portion of the shaft 5 and the guide pole erected on the main body of the pole base PB. Female screw 8 screwed into mounting part 9
And a protrusion 9a protruding from the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB, and a recess 30 provided on the annular rotation range restricting member 30.
b is loosely fitted. Further, a concave portion 9b provided at the upper end of the guide pole mounting portion 9 erected on the main body portion of the pole base PB, and a convex portion 3 provided on the annular rotation range limiting member 30.
0a, the annular rotation range limiting member 30
5 is located between the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB and the boss 7b of the lower flange 7 as shown in FIG. .

FIG. 5 (f) shows B in FIG. 5 (b).
It is sectional drawing in the -B line position. In the state of FIG. 5B described above, the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus. Adjust to the state of. FIG. 5 (c) in which the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. When the state shown in FIG. 5 is set, the position sensor P shown in FIG.
The hole 13b provided in the base portion 13a of the light-shielding plate 13 is inserted into the distal end of the shaft 5 of the guide pole GP with the light-shielding plate 13 of S being in a state where the edge thereof has the predetermined rotation phase described above. The light shielding plate 13 is fixed to the shaft 5 by press-fitting into the shaft 5.

Further, as described above, the annular rotation range limiting member 30 is provided on the annular rotation range restricting member 30 with respect to the convex portion 9a and the concave portion 9b provided at the upper end of the guide pole mounting portion 9 in the pole base PB. Annular rotation range restricting member 30 in a state where the concave portion 30b and the convex portion 30a are loosely fitted.
Is moved in the direction of the shaft 5 of the guide pole without rotating in the circumferential direction, and the state shown in FIG. 5D, that is, the guide pole in the pole base PB The concave portion 30b provided on the annular rotation range restricting member 30 loosely fitted to the convex portion 9a provided at the upper end of the mounting portion 9 is separated from the convex portion 9a.

The convex portion 30a provided on the annular rotation range limiting member 30 loosely fitted in the concave portion 9b provided on the upper end of the guide pole mounting portion 9 of the pole base PB is described above. In a state away from the concave portion 9b, the inner peripheral surface 30c of the annular rotation range limiting member 30 is fitted to the outer peripheral surface of the boss portion 7b of the lower flange 7, and the annular rotation range limiting member 30 is The annular rotation range limiting member 30 is connected and fixed to the guide pole GP such that the provided teeth 30g mesh with the teeth of the driven gear 7g. If knurling is applied to the outer peripheral surface of the boss portion 7b of the lower flange 7, the above-mentioned manner of fixing the both becomes even stronger.

As described above, the state in which the height position of the guide surface of the guide pole GP is adjusted to the predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. In the above, after the teeth 30g provided on the annular rotation range limiting member 30 are meshed with the teeth of the driven gear 7g as described above, the inner peripheral surface 30c of the annular rotation range limiting member 30 is lowered. When fitted on the outer peripheral surface of the boss 7b of the flange 7, the teeth 30g provided on the annular rotation range limiting member 30 and the teeth of the driven gear 7g provided on the lower flange 7 mesh. Due to the engagement, the annular rotation range limiting member 30 and the lower flange 7 are brought into a connected state in which they cannot slip in the rotation direction.

Thus, the guide pole GP in a state where the height of the guide surface is adjusted to the predetermined regular height for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus, One side surface of the convex portion 9a provided on the upper end of the guide pole mounting portion 9 of the pole base PB comes into contact with one side surface of the convex portion 30a provided on the annular rotation range limiting member 30. From the above state, the other side surface of the convex portion 9a provided on the upper end of the mounting portion 9 of the guide pole and the other side surface of the convex portion 30a provided on the annular rotation range limiting member 30. The above-described annular rotation range limiting member 30 is mounted on the guide pole GP in such a state that the rotation can be performed only within one rotation until the contact is made.

Next, in the pole base assembly shown in FIG. 7, the rotation range limiting member for preventing the guide pole GP from rotating more than one rotation is shown in FIGS. 8 (a) and 8 (b). As clearly shown in a specific configuration, a convex portion having a side surface that comes into contact with a side surface of a convex portion 9a protruding from an upper end of a mounting portion 9 of a guide pole erected on a main body portion of a pole base PB. 31a is provided at one end, and the other end is provided with teeth 31g that mesh with the teeth of the driven gear 7g provided on the lower flange 7, and the outer periphery of the boss 7b of the lower flange 7 is provided. Inner peripheral surface 3 to be fitted to the surface
1c.

In the pole base assembly shown in FIG.
A semi-annular rotation range limiting member 31 [see FIG. 8A] used as a constituent member thereof is provided on the outer peripheral portion of the shaft 5 of the guide pole GP shown in FIG. FIG. 7 is a cross-sectional view of a state in which the provided male screw 28 and the female screw 8 screwed to the mounting portion 9 of the guide pole erected on the main body of the pole base PB are screwed. As shown in (d) of FIG. 7 in (b) to (d),
In a state where the teeth 31g mesh with the teeth of the driven gear 7g, they are fitted and attached to a part of the outer peripheral surface of the boss 7b of the lower flange 7.

FIG. 7F is a cross-sectional view of a portion including the cross-section of the protruding portions 31a and 9a in FIG. 7D. In the state shown in FIG. 7B, the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus. Then, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus in FIG. (C) When brought into the state shown in the figure, the light-shielding plate 13 of the position sensor PS shown in FIG. In such a state, the hole 13b provided in the base 13a of the light shielding plate 13 is pressed into the tip 5a of the shaft 5 of the guide pole GP, and the light shielding plate 13 is fixed to the shaft 5.

In the above state, the teeth 31g provided on the semi-annular turning range limiting member 31 are engaged with the teeth of the driven gear 7g, so that the semi-annular turning range limiting member 31 is engaged. Is fitted on the outer peripheral surface of the boss 7b of the lower flange 7.

As described above, the state in which the height position of the guide surface of the guide pole GP is adjusted to the predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. In the case where the inner peripheral surface 31c of the semi-annular rotation range restricting member 31 is fitted to the outer peripheral surface of the boss 7b of the lower flange 7, in order to ensure recording / reproducing compatibility of the magnetic recording / reproducing apparatus. The guide pole GP in a state in which the height position of the guide surface is adjusted to a regular height position predetermined in advance is allowed to rotate only within one rotation from the above state. .

That is, the guide pole GP is provided on one side surface of the convex portion 9 a provided at the upper end of the guide pole mounting portion 9 of the pole base PB and on the semi-annular rotation range limiting member 31. From the state shown in FIG. 8B in which one side surface of the convex portion 31a is in contact with the convex portion 9a, the convex portion 9a provided at the upper end of the mounting portion 9 of the guide pole described above.
Of the convex portion 31a provided on the semi-annular rotation range limiting member 31 so that the rotation can be performed only within one rotation until the other side surface comes into contact with the other side surface of the projection 31a. In such a state, the above-described semi-annular rotation range limiting member 31 can be mounted on the guide pole GP.

In the pole base assembly described above with reference to FIGS. 1 to 8, the driven gear 7g provided on the pole base assembly side is formed integrally with the lower flange 7 of the guide pole GP. However, the pole base assembly shown in FIGS. 9 and 10 has a configuration in which a driven gear to be provided on the pole base assembly side is configured as a separate member from the lower flange 7 of the guide pole GP. FIG. 13 shows an example of a configuration (a pole base assembly described later with reference to FIGS. 13 and 14 also has a driven gear to be provided on the pole base assembly side).
This is a configuration example in the case of being configured separately from the lower flange 7 in P).

In the pole base assembly shown in FIG.
The rotation range limiting member for preventing the guide pole GP from rotating more than one rotation includes the rotation range limiting members shown in FIGS.
As shown in (c), a specific configuration is clearly shown in the projection 9a and the recess 9b projecting from the upper end of the mounting portion 9 of the guide pole erected on the main body of the pole base PB. A concave portion 27b loosely fitted to the convex portion 9a of the
b at one end, and a driven gear 27g is formed at the other end, and
An annular rotation range restricting member 27 having an inner peripheral surface 27c fitted to the outer peripheral surface of the boss 7b of the lower flange 7. In FIG. 10A, the illustration of the driven gear 27g is omitted.

As shown in FIG. 10 (b), an annular rotation range limiting member 27 (see FIGS. 10 (a) to 10 (c)) used as a component of the pole base assembly shown in FIG. After the shaft 5 of the guide pole GP is inserted through the male screw 28 provided on the outer peripheral portion of the shaft 5,
A female screw 8 screwed into a mounting portion 9 of a guide pole erected on the main body of the pole base PB is screwed together, and a mounting portion 9 of a guide pole erected on the main body of the pole base PB is screwed. The convex portion 9a protruding from the upper end of the ring member and the concave portion 27b provided on the annular rotation range limiting member 27 are loosely fitted,
Further, when the concave portion 9b provided on the upper end of the mounting portion 9 of the guide pole erected on the main body portion of the pole base PB and the convex portion 27a provided on the circular rotation range limiting member 27 are loosely fitted, 9B, the upper end of the guide pole mounting portion 9 erected on the main body of the pole base PB and the boss portion 7b of the lower flange 7 as shown in FIG.
Is located between.

FIG. 9 (f) shows B in FIG. 9 (b).
It is sectional drawing in the -B line position. In the state of FIG. 9B described above, the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproduction compatibility of the magnetic recording and reproducing apparatus. Adjust to the state of. FIG. 9C in which the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. When the state shown in FIG. 9 is set, the position sensor P shown in FIG.
The hole 13b provided in the base portion 13a of the light-shielding plate 13 is inserted into the distal end of the shaft 5 of the guide pole GP with the light-shielding plate 13 of S being in a state where the edge thereof has the predetermined rotation phase described above. The light shielding plate 13 is fixed to the shaft 5 by press-fitting into the shaft 5.

Further, as described above, the annular rotation range limiting member 27 is provided for the projection 9a and the recess 9b provided at the upper end of the guide pole mounting portion 9 in the pole base PB. Annular rotation range limiting member 27 in a state in which the recess 27b and the projection 27a are loosely fitted.
Is moved in the direction of the shaft 5 of the guide pole without rotating in the circumferential direction, and the state shown in FIG. 9D, that is, the guide pole in the pole base PB The concave portion 27b provided on the annular rotation range restricting member 27 loosely fitted to the convex portion 9a provided at the upper end of the mounting portion 9 is separated from the convex portion 9a,
Further, a convex portion 27a provided on an annular rotation range limiting member 27 which is loosely fitted in a concave portion 9b provided on an upper end of the guide pole mounting portion 9 in the pole base PB.
However, in a state separated from the concave portion 9b, the inner peripheral surface 27c of the annular rotation range limiting member 27 is fitted to the outer peripheral surface of the boss portion 7b of the lower flange 7, and the annular rotation is performed. The range limiting member 27 is connected and fixed to the guide pole GP. If knurling is applied to the outer peripheral surface of the boss portion 7b of the lower flange 7, the above-mentioned manner of fixing the both becomes even stronger.

As described above, with the magnetic recording / reproducing apparatus, the height of the guide surface of the guide pole GP is adjusted to a predetermined regular height for ensuring recording / reproducing compatibility. In the case where the inner peripheral surface 27c of the annular rotation range limiting member 27 is fitted to the outer peripheral surface of the boss 7b of the lower flange 7 as described above, the recording and reproducing compatibility of the magnetic recording and reproducing device The guide pole GP in a state where the height position of the guide surface is adjusted to a predetermined regular height position for securing is allowed to rotate only within one rotation from the above state. Will be.

That is, the guide pole GP is provided on one side surface of the convex portion 9 a provided at the upper end of the guide pole mounting portion 9 in the pole base PB, and the convex provided on the annular rotation range limiting member 27. From the state of FIG. 10C in which one side surface of the portion 27a is in contact, the projection 9a provided at the upper end of the mounting portion 9 of the guide pole is provided.
Can rotate only within one rotation until the other side surface of the second member and the other side surface of the convex portion 27a provided on the annular rotation range limiting member 27 come into contact with each other. In this state, the above-described annular rotation range limiting member 27 is mounted on the guide pole GP.

Next, in the pole base assembly shown in FIG. 11, teeth 34g and 34g (see FIG. 12 (a)) provided on the rotation range limiting member 34 are added to the teeth of a specific portion of the driven gear 7g. The engaged state is such that the guide pole GP cannot rotate more than one rotation. The rotation range limiting member 34 described above includes
As shown in FIGS. 12 (a) to 12 (c), the specific configuration is clearly shown, and the teeth 34g, which can be engaged with the teeth of the driven gear 7g,
34g and the boss 7 of the lower flange 7
A semi-annular (annular part) is provided with an inner peripheral surface 31c fitted to a part of the outer peripheral surface of b.

In the pole base assembly shown in FIG. 11, a semi-annular rotation range limiting member 34 (see FIG. 12 (a)) used as a constituent member thereof is shown in FIG. 12 (a). A male screw 28 provided on the outer peripheral portion of the shaft 5 of the guide pole GP
FIGS. 11B to 11D are cross-sectional views showing a state where the female screw 8 screwed to the mounting portion 9 of the guide pole erected on the main body of FIG. As shown in FIG. 11D, the lower flange 7 is attached to the guide pole GP such that the lower flange 7 is fitted to a part of the outer peripheral surface of the boss 7b and the teeth 34g, 34g are meshed with the teeth of the driven gear 7g. .

FIG. 11 (f) shows the teeth 34g and 3g of the semi-annular turning range limiting member 34 in FIG. 11 (d).
It is sectional drawing of the part containing the cross section of the meshing part of 4g and the tooth | gear of the driven gear 7g. In the state shown in FIG. 11B, the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus. Adjust to
Next, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording and reproduction compatibility of the magnetic recording and reproducing device in FIG.
1 (c) when the state shown in FIG.
The light shielding plate 13 of the position sensor PS shown in FIG.
With a hole 13b provided in the base 13a of the light-shielding plate 13 in a state where the edge thereof has the predetermined rotation phase described above.
Is pressed into the tip 5a of the shaft 5 of the guide pole GP, and the light shielding plate 13 is fixed to the shaft 5.

In the above state, the driven gear 7g is positioned 180 degrees symmetrically with the teeth of the driven gear 7g on the pole base assembly side engaged with the driving gear 22 provided on the fixed portion of the magnetic recording / reproducing apparatus. The teeth 34g provided on the semi-annular rotation range limiting member 34 are engaged with the teeth of the semicircular rotation range limiting member 34, and the inner peripheral surface 34c of the semi-annular rotation range limiting member 34 is 7 is fitted to the outer peripheral surface of the boss 7b. Boss 7 of lower flange 7 described above
If a knurl is applied to the outer peripheral surface of b, the above-mentioned manner of fixing both can be made strong.

As described above, the state in which the height of the guide surface of the guide pole GP is adjusted to the predetermined regular height for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. , The tooth of the driven gear 7g on the pole base assembly side meshed with the drive gear 22 and 1
The semi-annular rotation range limiting member 34 is brought into a state where the teeth 34g provided on the semi-annular rotation range limiting member 34 mesh with the teeth of the driven gear 7g at the symmetrical position of 80 degrees. When the inner peripheral surface 34c is fitted to the outer peripheral surface of the boss portion 7b of the lower flange 7, the magnetic recording / reproducing device has a predetermined regular height for ensuring recording / reproducing compatibility. As shown in FIG. 15, the guide pole GP in the state where the height position of the guide surface is adjusted to the position is allowed to rotate only within one rotation from the above state.

That is, in FIG. 15, reference numeral 22 denotes a driving gear, and 7g denotes a driven gear. (A) of FIG.
In the following description, the portion 7n of the driven gear 7g is a portion of the driven gear 7g that is prevented from meshing with the teeth of the driving gear 22. For example, in the case of the configuration described with reference to FIGS. The tooth of the gear 7g corresponds to a portion where the teeth 34g provided on the semi-annular rotation range limiting member 34 are engaged with each other, and a pole which will be described later with reference to FIGS. In the base assembly, it corresponds to a portion indicated by reference numeral 33n in the driven gear 33g. The driven gear 7g shown in FIG. 15 is rotated approximately １ ／ clockwise from the state shown in FIG. 15A, as shown in FIG. Obviously, it is only possible to rotate from the state shown in a) to a state (not shown) which has been rotated about 反 counterclockwise (not shown).

Next, the pole base assembly shown in FIGS. 13 and 14 has a driven gear 33 separate from the lower flange 7.
By using a driven gear having a configuration in which a specific portion of the teeth in g does not mesh with the driving gear 22,
12 and 13 show a pole base assembly capable of performing the same operation as the pole base assembly described above with reference to FIGS. In the pole base assembly shown in FIG. 13, the driven gear 33 used as a constituent member thereof
[See FIG. 14A] is a male screw 28 provided on the outer peripheral portion of the shaft 5 of the guide pole GP shown in FIG. 13 (b) to 13 (d) in a cross-sectional view showing a state where the female screw 8 screwed to the mounting portion 9 of the guide pole is screwed, as shown in FIG. 13 (d). The inner peripheral surface 33c of the driven gear 33 is a boss 7b of the lower flange 7.
And attached to the guide pole GP.

FIG. 13 (f) is a sectional view of the driven gear 33 used as a rotation range limiting member in FIG. 13 (d). In the state shown in FIG. 13 (b), the height position of the guide surface of the guide pole GP is set to a regular height position which is predetermined for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing apparatus. Then, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing device in FIG. (C) When the state shown in the figure is set, the light-shielding plate 13 of the position sensor PS shown in FIG. In such a state, the hole 13b provided in the base 13a of the light shielding plate 13 is pressed into the tip 5a of the shaft 5 of the guide pole GP, and
3 is fixed to the shaft 5.

In the above state, the driven gear 33g is 180 degrees symmetric with the teeth of the driven gear 33g on the pole base assembly side to be meshed with the driving gear 22 provided on the fixed portion of the magnetic recording / reproducing apparatus. 33n in
In other words, in a state where the component 33n that does not mesh with the teeth of the drive gear 22 is located, the inner peripheral surface 33c of the driven gear 33 used as the rotation range limiting member is moved to the boss 7b of the lower flange 7 Fit to the outer peripheral surface. As shown in FIG. 20B, only a part of the teeth of the driven gear 33 is used as the component 33n of the driven gear 33 that does not mesh with the teeth of the driving gear 22. It may be configured so as not to mesh with. If knurling is applied to the outer peripheral surface of the boss portion 7b of the lower flange 7, the above-mentioned manner of fixing both can be made strong.

As described above, the state in which the height position of the guide surface of the guide pole GP is adjusted to the predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. In a state where the portion 33n of the driven gear 33g is positioned 180 degrees symmetrically with the teeth of the driven gear 33g on the pole base assembly side meshed with the driving gear 22, the inner peripheral surface 34c of the driven gear 33g is set.
Is fitted to the outer peripheral surface of the boss portion 7b of the lower flange 7, the guide surface is set at a predetermined regular height position for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing device. As described above with reference to FIG. 15, the guide pole GP in the state where the height position of the guide pole is adjusted is allowed to rotate only within one rotation from the above state.

Next, the pole base assembly shown in FIGS. 16 to 20 will be described. The pole base assembly shown in FIG. 16 and FIG.
Into the screw hole 38 provided in the elastic plate 35.
Is fixed to the pole base PB, and the engaging teeth 37 fixed to the other end of the elastic plate 35 are engaged with the teeth of the driven gear 7g, so that the driven gear 7g does not rotate. 2 is a pole base assembly having the configuration described above.

In the pole base assembly shown in FIG. 16, a male screw 28 provided on the outer peripheral portion of the shaft 5 of the guide pole GP shown in FIG. (B) in FIG. 16 (b) to (f) of FIG. 16 showing a cross-sectional view in a state where the female screw 8 screwed to the mounting portion 9 of the provided guide pole is screwed. In the state (1), the height position of the guide surface of the guide pole GP is adjusted to a state of a regular height position which is predetermined in order to ensure recording / reproducing compatibility of the magnetic recording / reproducing apparatus.

Next, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing device, as shown in FIG. c) When the state shown in the figure is reached, the position sensor PS shown in FIG.
The light shielding plate 13 is provided with the hole 13b provided in the base 13a of the light shielding plate 13 in a state where the edge thereof has the predetermined rotation phase described above, and the distal end 5a of the shaft 5 of the guide pole GP. To fix the light shielding plate 13 to the shaft 5. Then, in the above state, the pole base P
An engagement tooth 37 fixed to the other end of an L-shaped elastic plate 35 fixed to B with a screw 39 is engaged with a tooth of the driven gear 7g to rotate the driven gear 7g during unloading. To prevent.

When the pole base PB is brought into a state of being connected to the base catcher at the time of completion of the loading operation, the projection 39 provided on the base catcher side.
Of the elastic plate 35 comes into contact with the engaging portions 35a, 35a provided on the elastic plate 35 to push the elastic plate 35, whereby the engaging teeth 37 fixed to the elastic plate 35 Release the engagement with 7g and guide pole G
Allow P to rotate.

Next, the pole base assembly shown in FIG. 18 and FIG.
Teeth 40g, 40 provided on the semi-annular rotation range limiting member 40
g (see FIG. 19A) is engaged so that the guide pole GP cannot be rotated more than one rotation, and the base end is fixed to the pole base PB by the screw 39. L-shaped elastic plate 3
5 is a pole base assembly having a configuration in which engagement teeth 37 fixed to the other end of the fifth engagement member are engaged with the rotation range limiting member 40 described above. As specifically shown in FIG. 19A, the rotation range limiting member 40 has teeth 40g that can engage with the teeth of the driven gear 7g, and the lower flange 7 Is formed as a semi-annular (annular part) having an inner peripheral surface 40c fitted to a part of the outer peripheral surface of the boss portion 7b.

In the pole base assembly shown in FIG. 18, a semi-annular rotation range limiting member 40 (see FIG. 19 (a)) used as a component thereof is shown in FIG. 19 (a). A male screw 28 provided on the outer periphery of the shaft 5 of the guide pole GP, and a pole base P
18 (b) to (d) and (f) of FIG. 18 showing a cross-sectional view of a state where the female screw 8 screwed to the mounting portion 9 of the guide pole erected on the main body of FIG. Figure 1)
As shown in FIG. 8D, the lower flange 7 is attached to a part of the outer peripheral surface of the boss 7b, and is attached to the guide pole GP such that the teeth 40 mesh with the teeth of the driven gear 7g.

FIG. 18 (g) includes a cross section of a meshing portion of the tooth 40g and the tooth of the driven gear 7g in the semi-annular rotation range limiting member 40 in FIG. 18 (d). It is sectional drawing of a part. In the state shown in FIG.
The height position of the guide surface of the guide pole GP is adjusted to a state of a regular height position which is predetermined in order to ensure recording / reproducing compatibility with respect to the magnetic recording / reproducing device.
The height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording and reproducing compatibility of the magnetic recording and reproducing device, as shown in FIG. When the state shown in FIG. 18E is reached, the light shielding plate 13 of the position sensor PS shown in FIG.
The hole 13b provided in the base 13a of the light-shielding plate 13 is inserted in a state where the edge thereof has the predetermined rotation phase described above.
The light-shielding plate 13 is fixed to the shaft 5 by press-fitting the distal end portion 5a of the shaft 5 of the guide pole GP.

In the above state, the driven gear 7g at a position 180 degrees symmetrical with the teeth of the driven gear 7g on the pole base assembly side engaged with the driving gear 22 provided on the fixed portion of the magnetic recording / reproducing apparatus. The teeth 40g provided on the semi-annular rotation range restricting member 40 are engaged with the teeth of the lower ring, and the inner peripheral surface 40c of the semi-annular rotation range restricting member 40 is connected to the lower flange. 7 is fitted to the outer peripheral surface of the boss 7b. Boss 7 of lower flange 7 described above
If a knurl is applied to the outer peripheral surface of b, the above-mentioned manner of fixing both can be made strong.

FIG. 18D shows the engagement teeth 37 fixed to the other end of the L-shaped elastic plate 35 whose base end is fixed to the pole base PB by screws 39. FIG. 18F shows a state of the pole base assembly at the time of the unloading operation in which the engagement is provided with the engaging portion provided on the semi-annular rotation range limiting member 40. 18 shows the state of the pole base assembly at the time of completion of the loading operation. When the pole base assembly is coupled to the base catcher in the state of FIG. 18 (f), the projection 39 provided on the base catcher side. Pushes the engaging portions 35a, 35a provided on the elastic plate 35, and the engaging teeth 37 fixed to the elastic plate 35 and the semi-annular rotation range limiting member 40 And released meshing of the engagement portion being kicked, the guide pole GP is to be rotated.

In the pole base assembly shown in FIG. 16, a male screw 28 provided on the outer peripheral portion of the shaft 5 of the guide pole GP shown in FIG. (B) of FIG. 16 in (b) to (f) of FIG. 16 showing a cross-sectional view of a state where the female screw 8 screwed to the mounting portion 9 of the provided guide pole is screwed. In the state (1), the height position of the guide surface of the guide pole GP is adjusted to a state of a regular height position which is predetermined in order to ensure recording / reproducing compatibility of the magnetic recording / reproducing apparatus.

Next, the height position of the guide surface of the guide pole GP is adjusted to a predetermined regular height position for ensuring the recording / reproducing compatibility of the magnetic recording / reproducing apparatus. c) The position sensor PS shown in FIG. 16E when the state shown in FIG.
The light shielding plate 13 is provided with the hole 13b provided in the base 13a of the light shielding plate 13 in a state where the edge thereof has the predetermined rotation phase described above, and the distal end 5a of the shaft 5 of the guide pole GP. To fix the light shielding plate 13 to the shaft 5. Then, in the above state, the pole base P
An engagement tooth 37 fixed to the other end of an L-shaped elastic plate 35 fixed to B with a screw 39 is engaged with a tooth of the driven gear 7g to rotate the driven gear 7g during unloading. To prevent.

When the pole base PB is brought into a state of being connected to the base catcher at the time of completion of the loading operation, the projection 39 provided on the base catcher side.
Of the elastic plate 35 comes into contact with the engaging portions 35a, 35a provided on the elastic plate 35 to push the elastic plate 35, whereby the engaging teeth 37 fixed to the elastic plate 35 Release the engagement with 7g and guide pole G
Allow P to rotate.

FIG. 26 is a perspective view of a part of the magnetic recording / reproducing apparatus during the loading operation.
FIG. 27 is a perspective view of a part of the magnetic recording and reproducing apparatus shown in FIG. 26 in a state where the loading operation is completed. FIG.
8 is a perspective view of a part of the magnetic recording / reproducing apparatus during the loading operation, and FIG. 29 is a perspective view of a part of the magnetic recording / reproducing apparatus shown in FIG. 28 in a state where the loading operation is completed. The magnetic recording / reproducing apparatus shown in FIGS. 26 to 29 and the magnetic recording / reproducing apparatus described above with reference to FIGS. And a power transmission system provided between them.

That is, the power transmission system provided between the motor Mg in the magnetic recording and reproducing apparatus described with reference to FIGS. 21 and 22 and the driven gear 7g in the pole base-side height control mechanism is , Which are all constituted by spur gears, the power transmission provided between the motor Mg in the magnetic recording / reproducing apparatus shown in FIGS. 26 to 29 and the driven gear 7g in the height control mechanism on the pole base side. In the system, at least a part of it, the warm W
And a worm gear.

First, in the magnetic recording / reproducing apparatus shown in FIGS. 26 and 27, the power transmission system of the height control mechanism provided on the fixed part side of the body is a worm W driven and rotated by the rotating shaft of the motor Mg. The light-shielding blade 16 of the rotary encoder RE is fixed to the rotating shaft of the motor Mg. The rotary encoder RE includes a light shielding blade 16 and a photo interrupter 17. The worm W is moved by a loading mechanism (not shown) so that the pole base PB moves along a predetermined movement path from the position of the magnetic tape cassette to the position of the drum assembly DA, and the magnetic tape of the magnetic tape is moved by the loading mechanism. In the state shown in FIG. 27 in which the loading operation is completed, 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 gear 7g (worm gear 7g) provided on the pole base PB as a driven gear in the height control mechanism on the pole base side.

The height control mechanism in the magnetic recording / reproducing apparatus shown in FIGS. 26 and 27 includes a worm W driven by the rotation shaft of the motor Mg as described above,
The gear 7g (worm gear 7g) as a driven gear provided on the pole base side is configured as an extremely simple configuration. Then, the loading operation of the magnetic tape by the loading mechanism is completed, and the tip of the pole base PB is connected to the pole base PB.
B is positioned by engagement with a base catcher BC provided corresponding to B, and a gear 7g provided as a driven gear of a height control mechanism on the pole base side
In the state after the worm W is meshed with the (worm gear 7g), the driven gear 7g fixed to the shaft 5 of the guide pole GP, that is, the worm, even if the guide pole GP attempts to rotate due to disturbance or other causes. Since the driven gear 7g operating as a gear cannot rotate, the height position of the guide pole GP does not change even if the guide pole GP is disturbed or other causes.

Next, in the magnetic recording and reproducing apparatus shown in FIGS. 28 and 29, the power transmission system of the height control mechanism provided on the fixed portion side of the body is a worm W driven and rotated by the rotating shaft of the motor Mg. A worm gear 43 meshing with the worm W; a worm gear 43; a gear 42 fixed to the same rotating shaft 41 as the worm gear 43; and a gear 19 meshing with the gear 42. , The gear 2 fixed to the same rotating shaft 21 as the gear 19 described above.
0, a driving gear 22 that meshes with the gear 20, and a driven gear 7g provided on the pole base side that can mesh with the driving gear 22. The light-shielding blade 16 of the rotary encoder RE is fixed to the rotation shaft of the motor Mg.

In the magnetic recording / reproducing apparatus shown in FIGS. 28 and 29, the operation of the loading mechanism (not shown) causes the pole base PB to move along the predetermined moving path from the position of the magnetic tape cassette to the position of the drum structure DA. In the state shown in FIG. 29 in which the magnetic tape loading operation by the loading mechanism has been completed, the tip of the pole base PB is
When the base catcher BC provided corresponding to B is engaged and positioned, a gear 7g (worm) provided as a driven gear in the pole base-side height control mechanism on the pole base PB described above. Gear 7g)
The driving gear 22 is meshed with.

The height control mechanism in the magnetic recording / reproducing apparatus shown in FIGS. 28 and 29 includes a worm W driven by the rotating shaft of the motor Mg as described above,
It is composed of a worm gear 43, a plurality of gears 42, 19, 20 and a drive gear 22, and a driven gear 7g. Then, the loading operation of the magnetic tape by the loading mechanism is completed, and the leading end of the pole base PB is positioned by engagement with the base catcher BC provided corresponding to the pole base PB. After the drive gear 22 is meshed with the driven gear 7g of the side height control mechanism, even if the guide pole GP tries to rotate due to disturbance or other causes, the worm gear provided in the power transmission system. 4
3 cannot rotate, so that the height of the guide pole GP does not change even if the guide pole GP is disturbed or other causes.

[0099]

As is apparent from the above description, the pole base assembly of the magnetic recording / reproducing apparatus of the present invention has a predetermined rotation locus plane relative to the 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 rotary magnetic head provided so as to be formed at the position. The height of the first and second guide poles which are individually arranged in the running path between the winding start side and the winding end side of the magnetic tape to be wound on the drum peripheral surface is adjusted by the rotation of the rotary magnetic head. Should be given to a closed loop automatic control system for changing the trajectory so as to match the recording trace of the magnetic tape,
Means for limiting the rotation range of the movable member in the position sensor used as a part of the component that generates information on the height of the guide pole to within one rotation of the guide pole set at the reference height position A pole base assembly that is configured to include a movable member of a position sensor attached to a guide pole set at a reference height position at a predetermined attachment phase, and at the reference height position described above. As described above, by setting the guide pole, the rotation range limiting member of the guide pole for preventing the guide pole from rotating more than one rotation from the above-mentioned state is fitted and fixed to the component of the guide pole. Conventional problems can be solved well.

[Brief description of the drawings]

FIG. 1 is a view for explaining a guide pole assembly.

FIG. 2 is a view for explaining a guide pole assembly.

FIG. 3 is a view for explaining a guide pole assembly.

FIG. 4 is a view for explaining a guide pole assembly.

FIG. 5 is a view for explaining a guide pole assembly.

FIG. 6 is a view for explaining a guide pole assembly.

FIG. 7 is a view for explaining a guide pole assembly.

FIG. 8 is a view for explaining a guide pole assembly.

FIG. 9 is a view for explaining a guide pole assembly.

FIG. 10 is a view for explaining a guide pole assembly.

FIG. 11 is a view for explaining a guide pole assembly.

FIG. 12 is a view for explaining a guide pole assembly.

FIG. 13 is a view for explaining a guide pole assembly.

FIG. 14 is a view for explaining a guide pole assembly.

FIG. 15 is a view for explaining a guide pole assembly.

FIG. 16 is a view for explaining a guide pole assembly.

FIG. 17 is a view for explaining a guide pole assembly.

FIG. 18 is a view for explaining a guide pole assembly.

FIG. 19 is a view for explaining a guide pole assembly.

FIG. 20 is a view for explaining a guide pole assembly.

FIG. 21 is a perspective view of a part of the magnetic recording / reproducing apparatus during a loading operation.

22 is a perspective view of a part of the magnetic recording / reproducing apparatus shown in FIG. 22 in a state where a loading operation has been completed.

FIG. 23 is a view for explaining a conventional example of a guide pole provided on a pole base.

FIG. 24 is a diagram for explaining a problem of a conventional example of a guide pole provided on a pole base.

FIG. 25 is a diagram for explaining the operation of the position sensor.

FIG. 26 is a perspective view of a part of the magnetic recording / reproducing apparatus during a loading operation.

FIG. 27 is a perspective view of a part of the magnetic recording and reproducing apparatus shown in FIG. 26 in a state where a loading operation has been completed.

FIG. 28 is a perspective view of a part of the magnetic recording / reproducing apparatus during a loading operation.

FIG. 29 is a perspective view of a part of the magnetic recording and reproducing apparatus shown in FIG. 28 in a state where a loading operation has been completed.

[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: motor, GP: guide pole, S
P: inclined pole, T: magnetic tape, RE: rotary encoder, PS: position sensor, W: worm, 5: shaft of guide pole, 7: lower flange, 7g, 27g,
33g: driven gear, 8a: female screw, 18, 19, 20 ...
Gears, 10: elastic body, 11: upper flange, 12: roller, 13: light shielding plate, 15: rotating shaft of motor Mg, 16:
A light-shielding blade plate which constitutes a part of the rotary encoder RE; 24 a photointerrupter; 22 a drive gear;
Reference numeral 8: male screw, 29: spring, 30: annular rotation range limiting member, 31: semi-annular rotation range limiting member, 35
... elastic plate,

Claims (8)

[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. A closed loop automatic control system for changing the heights of the first and second guide poles so that the rotation locus of the rotary magnetic head coincides with the recording trace of the magnetic tape. To give
Means for limiting the rotation range of the movable member in the position sensor used as a part of the component that generates information about the height of the guide pole to within one rotation of the guide pole set at the reference height position A pole base assembly that is provided with a movable member of a position sensor attached to a guide pole set at a reference height position at a predetermined attachment phase, and at the reference height position described above. A pole base assembly in which a guide pole rotation range limiting member for preventing the set guide pole from rotating more than one rotation from the above state is fitted and fixed to a component of the guide pole. 2. A guide pole rotation range limiting member which is in contact with at least one engaging portion formed on a pole base provided with a screw screwed into a screw provided on a shaft of the guide pole. 2. The pole base assembly according to claim 1, wherein the pole base assembly has a releasable engaging portion and an inner peripheral surface fitted to at least a part of an outer peripheral surface of a boss portion of a lower flange of the guide pole. . 3. A guide pole rotating range limiting member which contacts at least one engaging portion formed on a pole base provided with a screw which is screwed into a screw provided on a shaft of the guide pole. A driven gear that has a releasable engaging portion, has an inner peripheral surface fitted to at least a part of the outer peripheral surface of the boss portion of the lower flange of the guide pole, and supplies rotational force to the shaft of the guide pole. 2. The pole base assembly according to claim 1, wherein said pole base assembly has a detent which meshes with said teeth. 4. A guide pole rotation range restricting member which is in contact with at least one engaging portion formed on a pole base provided with a screw screwed into a screw provided on a shaft of the guide pole. A driven gear that has a releasable engaging portion, has an inner peripheral surface fitted to at least a part of the outer peripheral surface of the boss portion of the lower flange of the guide pole, and supplies rotational force to the shaft of the guide pole. 2. The pole base assembly according to claim 1, wherein the pole base assembly comprises: 5. A guide pole rotation range restricting member having an inner peripheral surface fitted to an outer peripheral surface of a boss portion of a lower flange of the guide pole, and a follower for supplying a rotational force to a shaft of the guide pole. The pole base assembly according to claim 1, wherein the gear includes a component that does not mesh with the drive gear. 6. A magnetic recording / reproducing apparatus, which is wound around a part of a 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 a body of a magnetic recording / reproducing apparatus. The recording and reproducing operations on the magnetic tape are performed, and the magnetic tape to be wound around a part of the drum peripheral surface is individually moved on the traveling path between the winding start side and the winding end side around the drum peripheral surface. A closed loop automatic control system for changing the heights of the first and second guide poles so that the rotation locus of the rotary magnetic head coincides with the recording trace of the magnetic tape. To give
Means for limiting the rotation range of the movable member in the position sensor used as a part of the component that generates information about the height of the guide pole to within one rotation of the guide pole set at the reference height position A pole base assembly that is provided with a movable member of a position sensor attached to a guide pole set at a reference height position at a predetermined attachment phase, and at the reference height position described above. The other end of the elastic member, one end of which is fixed to the pole base, as a guide pole rotation range limiting member for preventing the set guide pole from rotating more than one rotation from the above state during unloading. In this configuration, the components other than the magnetic tape running path in the components of the guide pole are configured as a brake portion that resiliently pressurizes. Pole base assembly comprising equipped with. 7. 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 rotation 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. A closed loop automatic control system for changing the heights of the first and second guide poles so that the rotation locus of the rotary magnetic head coincides with the recording trace of the magnetic tape. To give
Means for limiting the rotation range of the movable member in the position sensor used as a part of the component that generates information about the height of the guide pole to within one rotation of the guide pole set at the reference height position A pole base assembly that is provided with a movable member of a position sensor attached to a guide pole set at a reference height position at a predetermined attachment phase, and at the reference height position described above. The other end of an elastic member, one end of which is fixed to a pole base, as a guide pole rotation range limiting member for preventing the set guide pole from rotating more than one rotation from the above state during unloading. In this way, the components other than the running path of the magnetic tape in the components of the guide pole can be configured as a brake portion for resiliently pressing, And an inner peripheral surface fitted to the outer peripheral surface of the boss portion of the lower flange of the guide pole, and a driven gear that supplies a rotational force to the shaft of the guide pole has a component that does not mesh with the drive gear. Pole base assembly using things. 8. A part of a drum peripheral surface is wound around a fixed portion of a body of a magnetic recording / reproducing apparatus by a rotating magnetic head provided so that a rotation trajectory surface is formed at a predetermined position. 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. A closed loop automatic control system for changing the heights of the first and second guide poles so that the rotation locus of the rotary magnetic head coincides with the recording trace of the magnetic tape. To give
Means for limiting the rotation range of the movable member in the position sensor used as a part of the component that generates information on the height of the guide pole to within one rotation of the guide pole set at the reference height position A pole base assembly that is provided with a movable member of a position sensor attached to a guide pole set at a reference height position at a predetermined attachment phase, and at the reference height position described above. The other end of an elastic member, one end of which is fixed to a pole base, as a guide pole rotation range limiting member for preventing the set guide pole from rotating more than one rotation from the above state during unloading. The brake portion that resiliently presses the components other than the magnetic tape running path in the guide pole components, and the loading motion End pole base assembly comprising includes those that are configured to include a component to release the brake operation in the brake portion in contact with the brake release member which those provided on the fixed portion of the machine body at the time of assembly.