JP2000048333A - Rotary head drum device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive the simplification of manufacturing process and the reduction of cost in a rotary head drum device for performing the magnetic recording/reproducing process against a magnetic tape running in contact along upper and lower drums by a rotating magnetic head. SOLUTION: The rotary head drum device for performing the magnetic recording/reproducing process against the magnetic tape is constituted so as to be provided with the lower drum 21 fixed to a chassis, the resin upper drum 22 fixed on this lower drum 21, and a metallic intermediate drum 23 provided with the magnetic head 24 performing the magnetic recording/reproducing process against the magnetic tape while being arranged to rotate at a prescribed rotating speed between these lower drum 21 and upper drum 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head drum device, and more particularly to a rotary head drum device for performing a magnetic recording / reproducing process on a magnetic tape running in contact with upper and lower drums by a rotating magnetic head.

[0002]

2. Description of the Related Art For example, a video tape recorder (VT)
R) and Digital Audio Tape Recorder (DAT)
The helical scan magnetic recording is performed on the running magnetic tape. Therefore, VTR and DAT
Is provided with a rotary head drum device for rotating the magnetic head so that the magnetic head forms a track obliquely to the running direction of the magnetic tape.

A conventional rotary head drum device includes a fixed drum and a rotary drum, and a magnetic head is provided on the rotary drum. Further, it is necessary to attach a magnetic tape to the rotating drum in a helical manner, and therefore, the rotating head drum device is attached in a state of being inclined with respect to the main chassis. Therefore, the rotary head drum device is attached to the main chassis in an inclined state by using the drum base.

FIG. 3 shows an example of a conventional rotary head drum device. As shown in FIG. 1, the rotary head drum device 1 is generally composed of a fixed drum 2, a rotary drum 3, a magnetic head 4, a shaft 5, a motor unit 6, a rotary transformer 7, and the like. The fixed drum 2 is fixed to a drum base 8, and has a configuration in which a shaft 5 is supported at a central portion thereof via two bearings 9. The fixed drum 2 is made of metal and fixed to the drum base 8, so that it does not rotate during magnetic recording and reproduction.

[0005] The rotary drum 3 is a metal part and is fixed to the upper end of the shaft 5. A motor 6 is provided at the lower end of the shaft 5, and the shaft 5 is driven to rotate by driving the motor 6. Therefore, the rotary drum 3 is configured to rotate by the motor 6 being driven and the shaft 5 being rotated.

[0006] The magnetic head 4 is arranged on the lower surface of the rotating drum 3. The magnetic head 4 is arranged on a head base 10 and is attached to the rotating drum 3 by a head fixing screw 11. By the way, the magnetic head 4 is provided with an azimuth angle, and it is necessary to precisely adjust the azimuth angle to a predetermined angle in order to perform a good reproduction process. In order to perform a good magnetic recording / reproducing process, it is necessary to determine the height of the magnetic head 4 with high accuracy.

For this purpose, the rotary drum 3 is provided with an adjusting mechanism for adjusting the position of the magnetic head 4. The adjusting mechanism of the magnetic head 4 includes a tap portion 12 provided on the rotary drum 3 and an adjusting screw 13 (a set screw with a hexagonal hole) screwed to the tap 12. As illustrated, the lower end of the adjustment screw 13 is configured to abut on the upper surface of the head base 10.
Therefore, the adjusting screw 1 is used from above the tap 12 using a jig.
By adjusting the degree of screw 3, the head base 10 is biased and the position of the magnetic head 4 can be adjusted.

The rotary transformer 7 is provided for transmitting and receiving signals between the magnetic head 4 provided on the rotating rotary drum 3 and the flexible board 14 provided on the fixed drum 3. That is, at the time of recording, a recording signal is supplied from the flexible substrate 14 to the magnetic head 4 via the rotary transformer 7, and at the time of reproduction, the generated signal read from the magnetic tape by the magnetic head 4 is transmitted to the rotary transformer 7. It is configured to be supplied to the flexible substrate 14 through the flexible substrate 14.

[0009]

However, if the rotary drum 4 is configured to rotate on the fixed drum 2 as described above, it is necessary to process the rotary drum 2 with high precision. That is, in order for the rotating drum 2 to rotate smoothly without rattling, it is necessary to form the rotating drum 2 so as to have high roundness.

[0010] In addition, from the viewpoint of maintaining good running of the magnetic tape, it is necessary to make the entire circumference of the rotary drum 2 a good smooth surface. Here, the reason why the entire circumference of the rotary drum 2 is made to be a good smooth surface is that the rotary drum 2 rotates, and thus the entire circumference of the rotary drum 2 comes into sliding contact with the magnetic tape. However, it is difficult to process and form the metal rotary drum 4 with high precision as described above, so that the process of processing the rotary drum 4 is complicated and the product cost of the rotary head drum device 1 increases. There was a problem.

The adjustment mechanism of the magnetic head 4 has a structure in which the magnetic head 4 is disposed on the lower surface of the rotary drum 2. Therefore, the adjustment mechanism must be provided on the rotary drum 2. However, tapping (hole processing) on the rotary drum 2 requiring high accuracy as described above has a problem in terms of accuracy. The present invention has been made in view of the above points, and has as its object to provide a rotary head drum device capable of simplifying a manufacturing process and reducing costs.

[0012]

The above-mentioned object can be attained by taking the following means. The rotary head drum device according to the first aspect of the present invention includes a lower drum fixed to a chassis, a resin upper drum fixed on the lower drum, and a predetermined rotation between the lower drum and the upper drum. A metal middle drum provided with a magnetic head for performing a magnetic recording / reproducing process on a magnetic tape running while being attached to the upper and lower drums. It is a feature.

According to a second aspect of the present invention, in the rotary head drum device according to the first aspect, an exposed portion where the middle drum is exposed to the outside is formed in a part of the upper drum, and the exposed portion is formed. Characterized in that the magnetic head can be adjusted through the adjustment.

According to a third aspect of the present invention, in the rotary head drum device according to the second aspect, a positioning mechanism for adjusting the magnetic head includes a tap portion formed on the middle drum, and the tap portion. And an adjusting screw for pressing and biasing the magnetic head according to the degree of screwing.

According to a fourth aspect of the present invention, in the rotary head drum device according to any one of the first to third aspects, the upper drum has high precision only in a predetermined range to which the magnetic tape is attached. It is characterized by having a circular shape. Further, according to a fifth aspect of the present invention, in the rotary head drum device according to any one of the first to fourth aspects, the lower drum is formed of a resin.

Each of the above means operates as follows.
According to the first aspect of the present invention, since the upper drum is formed as a fixed drum and formed of resin, the forming can be simplified, and the cost of the rotary head drum device can be reduced. According to the second aspect of the present invention, an exposed portion where the middle drum is exposed to the outside is formed in a part of the upper drum, and the magnetic head is adjusted (such as azimuth adjustment) through the exposed portion.
The adjustment process of the magnetic head can be easily performed even if the upper drum is a fixed drum. Also, by making the upper drum made of resin,
The exposed portion can be easily formed.

According to the third aspect of the present invention, since the adjusting screw for adjusting the magnetic head is screwed to the tap formed on the middle drum made of metal, the tap of the tap is formed. The strength is high, and thus a highly reliable adjustment process can be performed. According to the fourth aspect of the present invention, the upper drum can be easily formed by forming the upper drum into a high-precision circular shape only in a predetermined range to which the magnetic tape is attached.

That is, in a rotary head drum device having a configuration in which the upper drum rotates, the entire circumference of the upper drum comes into contact with the magnetic head as it rotates, so that it is necessary to process the entire circumference with high precision. However, by using the upper drum as a fixed drum, the position where the magnetic tape is attached is limited to a certain predetermined range. Therefore, if only the predetermined range is formed into a highly accurate circular shape, a smooth magnetic recording / reproducing process of the magnetic tape can be realized.

Further, in a portion other than the predetermined range, even if the accuracy is reduced, no problem occurs in the magnetic recording / reproducing processing on the magnetic tape. Therefore, it is not necessary to process the entire circumference of the upper drum with high precision, and the upper drum can be easily formed. Furthermore, according to the fifth aspect of the invention, since the lower drum is formed of resin together with the upper drum, the molding of the lower drum can be simplified, and the cost of the rotary head drum device can be further reduced. Can be.

[0020]

Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a rotary head drum device 20 according to one embodiment of the present invention. FIG. 1 is a sectional view of the rotary head drum device 20, and FIG. 2 is a plan view of the rotary head drum device 20 (a view taken along the line AA in FIG. 1).

The rotary head drum device 20 includes a lower drum 21, an upper drum 22, a middle drum 23, a magnetic head 24, a shaft 25, a motor unit 26, a rotary transformer 27, and the like. In this embodiment,
The lower drum 21 is formed of a resin (the resin portion is shown in satin). The lower drum 21 is fixed to a chassis of a magnetic recording / reproducing processing device (DAT or the like) not shown, so that the lower drum 21 does not rotate during magnetic recording / reproducing.

A shaft 25 is press-fitted into a central portion of the lower drum 21, and a fixed transformer half 27b constituting a rotary transformer 27 is disposed above the lower drum 21. This fixed transformer half 27
A coil is wound around b, and this coil is connected to a signal flexible substrate 34 fixed to the lower drum 21.

A tape attachment surface 39 is formed in a predetermined area of the lower drum 21 to which a magnetic tape (not shown) is attached. Since the tape abutment surface 39 is a surface on which the magnetic tape abuts and travels during magnetic recording and reproduction, the tape abutment surface 39 is formed with high precision so as to have a predetermined curvature and high smoothness. As described above, since the lower drum 21 is made of resin, molding can be simplified as compared with the lower drum made of metal, and the cost of the rotary head drum device 20 can be reduced. In addition, since the lower drum 21 does not rotate, the tape abutment surface 39 that requires high accuracy may be formed only in a predetermined range where the magnetic tape abuts. Therefore, the tape attachment surface 39 can be easily formed.

The upper drum 22 is fixed to the upper end of a shaft 25 erected on the lower drum 21 by, for example, press fitting. Therefore, like the lower drum 21, the upper drum 22 is also fixed to the chassis of the magnetic recording / reproducing processing device, and does not rotate during magnetic recording / reproducing. In the present embodiment, the upper drum 22 is also formed of resin (the resin portion is shown in satin).

On the lower surface of the upper drum 22, a drive coil 40 constituting a part of the motor section 26 is provided. The drive coil 40 is connected to a drive flexible substrate 35 fixed to the upper drum 22. Further, a tape attachment surface 38 is formed in a predetermined range of the upper drum 22 where the magnetic tape (not shown) is attached. Since the tape abutment surface 38 is a surface on which the magnetic tape abuts and travels during magnetic recording and reproduction, the tape abutment surface 38 is formed with high precision so as to have a predetermined curvature and high smoothness.

Further, in this embodiment, as shown in FIG.
The upper drum 22 does not have a circular shape in a plan view, but has a substantially half-moon shape by forming the exposed portion 37. By forming the exposed portion 37 in this manner, the middle drum 2 located below the upper drum 22
Reference numeral 3 denotes a configuration exposed to the outside. As described above, since the upper drum 22 is also made of resin in the present embodiment, molding can be simplified as compared with a configuration in which the upper drum 22 is formed of metal, and therefore, the rotary head drum device 20
Cost can be reduced.

Also, like the lower drum 21, the upper drum 22
Since the tape does not rotate, the tape abutment surface 38 that requires high accuracy may be formed only in a predetermined range where the magnetic tape abuts. That is, the conventional rotary drum 3 described with reference to FIG.
In the rotary head drum device 1 having the above, since the entire outer circumference of the rotary drum 3 is in contact with the magnetic tape, it is necessary to process the entire circumference with high precision.

However, in this embodiment, since the upper drum 22 does not rotate, the position where the magnetic tape abuts is limited to a certain predetermined range (tape abutment surface 39). Therefore, if only the tape attachment surface 39 is formed in a highly accurate circular shape, smooth magnetic recording / reproducing processing of the magnetic tape can be realized.
In addition, in the outer peripheral portion other than the tape abutment surface 39, even if the accuracy is reduced, there is no problem with the magnetic recording / reproducing process on the magnetic tape.

Therefore, since it is not necessary to process the entire circumference of the upper drum 22 with high precision, it is possible to easily form the upper drum 22, thereby reducing the cost of the rotary head drum device 20. it can. Middle drum 2
3 is rotatably attached to the shaft 25 described above. Specifically, the shaft 25 is provided with a pair of bearings 29 (ball bearings), and the middle drum 23 is configured to be supported by the bearings 29. In this embodiment, the drum 23 is formed of metal.

At the lowermost end of the middle drum 23, a rotary transformer half 27a constituting the rotary transformer 27 is disposed. A coil is wound around the rotation-side transformer half 27 a, and an end line of the coil is connected to the magnetic head 24. The rotating transformer half 27a is connected to the lower drum 2 with the middle drum 23 attached.
1 is configured to face the fixed-side transformer half 27b.

Thus, the rotary transformer 27 is formed, and signals can be transmitted and received between the transformer halves 27a and 27b. Therefore, at the time of recording, the recording signal for recording on the magnetic tape is transmitted to the signal flexible substrate 34.
Is supplied to the magnetic head 24 via the rotary transformer 27, and the generated signal read from the magnetic tape by the magnetic head 24 at the time of reproduction is transmitted to the rotary transformer 2.
7 to the flexible substrate 34.

The motor unit 2 is provided above the middle drum 23.
6 are provided. The motor unit 26 includes a drive coil 40 provided on the upper drum 22 and the middle drum 2.
3 is provided. When a drive current is supplied to the drive flexible substrate 35, the drive coil 40 is energized.
Therefore, the middle drum 23 provided with the magnet 36 is configured to be rotationally biased. In the present embodiment, the size of the magnet 36 is set to a minimum size sufficient to rotate the middle drum 23 at a predetermined rotation speed.

The magnetic head 24 is arranged on the lower surface of the middle drum 23. The magnetic head 24 is also thinned in order to cope with high-density recording. Therefore, the magnetic head 24 is arranged on the head base 30 and then attached to the middle drum 23 by the head fixing screw 31. I have.
Further, in the rotary drum device 20 of the present embodiment, the four magnetic heads 24 are arranged at 90 ° intervals, and the magnetic heads 24 separated by 180 ° form a pair,
One is configured to function as a recording-only head, and the other is configured to function as a reproduction-only head.

As described above, the magnetic head 24
Is provided with an azimuth angle, and it is necessary to precisely adjust the azimuth angle to a predetermined angle in order to perform a good reproduction process. In order to perform a good magnetic recording / reproducing process, it is necessary to determine the height of the magnetic head 24 with high accuracy. Therefore, also in this embodiment, an adjustment mechanism for adjusting the position of the magnetic head 24 is provided. The adjustment mechanism of the magnetic head 24 is
, And an adjusting screw 33 (a set screw with a hexagonal hole) screwed to the tap 32.

The lower end of the adjusting screw 33 is
0 is in contact with the upper surface. Accordingly, by adjusting the degree of screwing of the adjusting screw 33 from above the tap 32 using a jig, the head base 30 is biased and the position of the magnetic head 4 can be adjusted. by the way,
In the configuration in which the upper drum 22 fixed to the upper portion of the middle drum 23 on which the magnetic head 24 is disposed as in the present embodiment, the upper drum 22 becomes an obstacle, and the position of the magnetic head 24 cannot be adjusted. It is possible.

However, in the rotary head drum device 20 according to the present embodiment, the exposed portion 37 from which the middle drum 23 is exposed to the outside is formed in a part of the upper drum 22 as described above. Therefore, as shown in FIG. 2, by rotating the middle drum 23 and moving the position of the adjustment screw 33 to a position exposed from the upper drum 22, adjustment of the magnetic head J24 via the exposed portion 37 (adjustment of azimuth, etc.) ) Can be performed. Therefore, even when the upper drum 22 is a fixed drum, the adjustment processing of the magnetic head 24 can be easily performed.

In this embodiment, the adjusting screw 33 for adjusting the magnetic head 24 is screwed to a tap portion 32 formed on the middle drum 23 made of metal.
Now, assuming that the tap portion is disposed on the upper drum 22 made of resin, the tap portion formed on the resin cannot provide sufficient tap strength, and the adjusting screw may be loosened or may be magnetic. The adjustment of the head 24 cannot be performed with high accuracy.

However, by providing the tap portion 32 on the metal drum 23 made of metal, the tap strength of the tap portion 32 can be made strong enough to adjust the magnetic head 24. High adjustment processing can be performed.

[0039]

According to the present invention as described above, the following various effects can be realized. According to the first aspect of the present invention, since the upper drum is formed as a fixed drum and formed of resin, the forming can be simplified, and the cost of the rotary head drum device can be reduced.

According to the second aspect of the present invention, even when the upper drum is a fixed drum, the adjustment processing of the magnetic head can be easily performed. Further, since the upper drum is made of resin, the exposed portion can be easily formed. Also,
According to the third aspect of the present invention, since the adjusting screw for adjusting the magnetic head is screwed to the tap portion formed on the middle drum made of metal, the tap strength of the tap portion is strong. A highly reliable adjustment process can be performed.

According to the fourth aspect of the present invention, it is not necessary to process the entire circumference of the upper drum with high precision, so that the upper drum can be easily formed. Furthermore, according to the fifth aspect of the invention, since the lower drum is formed of resin together with the upper drum, the molding of the lower drum can be simplified, and the cost of the rotary head drum device can be further reduced. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view of a rotary head drum device according to an embodiment of the present invention.

FIG. 2 is a plan view of a rotary head drum device according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional rotary head drum device.

[Explanation of symbols]

 Reference Signs List 20 rotating head drum device 21 lower drum 22 upper drum 23 middle drum 24 magnetic head 25 shaft 26 motor unit 27 rotary transformer 30 head base 32 tap unit 33 adjusting screw 36 magnet 37 exposed unit 38, 39 Tape contact surface

Claims (5)

[Claims] 1. A lower drum fixed to a chassis, an upper drum made of resin fixed on the lower drum, and configured to rotate at a predetermined rotation speed between the lower drum and the upper drum. And a metal middle drum provided with a magnetic head for performing a magnetic recording / reproducing process on a magnetic tape running in contact with the upper and lower drums. 2. The rotary head drum device according to claim 1, wherein an exposed portion where the middle drum is exposed to the outside is formed in a part of the upper drum, and the magnetic head is adjusted via the exposed portion. A rotary head drum device characterized in that it is configured to obtain a rotating head drum device. 3. The rotary head drum device according to claim 2, wherein: a positioning mechanism for adjusting the magnetic head includes: a tap formed on the middle drum; A rotary head drum device comprising an adjusting screw for pressing and biasing a magnetic head. 4. The rotary head drum device according to claim 1, wherein the upper drum has a highly accurate circular shape only in a predetermined range to which the magnetic tape is attached. Rotating head drum device. 5. The rotary head drum device according to claim 1, wherein the lower drum is formed of a resin.