JP2000048434A - Rotary magnetic head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary magnetic head device which is capable of changing the lead height of a tape lead part of a fixed drum by a simple constitution and at a low cost. SOLUTION: The rotary magnetic head device is provided with the fixed drum 11, a rotary drum 14 which is rotably supported to the fixed drum via an axis 12 and a magnetic head 15 which is attached to the rotary drum 14 so as to be projected from the outer peripheral surface thereof. In the rotary magnetic head device 10, a magnetic tape is guided by bringing a side edge of the magnetic tape into contact with the tape lead part 18 which is provided as a step part at an outer peripheral surface of the fixed drum 11. The fixed drum 11 of this rotary magnetic head device 10 is constituted of a base part 21 which rotatably supports the rotary drum via a shaft and a drum part 22 of an another body which delineates an outer peripheral surface containing the tape lead part fixed and held to the base part 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating magnetic head device for recording and reproducing data on and from a magnetic tape, and more particularly to a so-called helical scan type rotating device provided with a tape lead portion for guiding the running of the magnetic tape. The present invention relates to a magnetic head device.

[0002]

2. Description of the Related Art Conventionally, a video tape recorder (VT)
R), DDS, digital audio tape recorder (D
A helical scan type rotary magnetic head device used in AT) or the like is configured as shown in, for example, FIG. 3 or FIG. The rotary magnetic head device 1 shown in FIG. 3 is used for, for example, a VHSVTR capable of magnetic recording and reproduction, is configured as a shaft rotation type, and has a fixed lower drum 2 having a substantially cylindrical outer shape. Fixed lower drum 2
A bearing 3 fixed by press fitting or the like therein, a rotating shaft 4 rotatably supported by the bearing 3 around the center line of the fixed lower drum 2, and a substantially cylindrical shape fixed and held by the rotating shaft 4. A rotating upper drum 5 having an outer shape, a magnetic head 6 attached to the rotating upper drum 5 so as to protrude outside the outer peripheral surface from between the fixed lower drum 2 and the rotating upper drum 5, Motor 7 and a rotary transformer 8 are included.

The fixed lower drum 2 has a tape running surface 2a on its outer peripheral surface, and the radius thereof is formed slightly smaller than the radius of the outer cylindrical surface 2b of the fixed lower drum 2.
Thereby, a step, that is, a tape lead portion 2c is formed between the tape running surface 2a and the outer cylindrical surface 2b as shown in the figure. The tape lead portion 2c extends spirally in the tape running direction, that is, inclines with respect to a plane orthogonal to the central axis of the fixed lower drum 2. The rotating upper drum 5 is formed in a substantially hollow cylindrical shape having an open upper end and a closed lower end, and a through hole 5 for receiving the rotating shaft 4 at the center.
a.

The magnetic head 6 records or reproduces a magnetic signal with respect to a magnetic tape running along the tape lead portion 2c, and its coil (not shown) has
It is connected to a rotary coil of a rotary transformer 8 described later. The motor 7 includes a rotor 7a mounted near the lower end of the rotating shaft 4 and a stator 7b mounted below the fixed lower drum 2 and facing the rotor 7a at a predetermined interval. The rotor 7a is formed in a flat hollow cylindrical shape whose upper part is open, and an annular magnet 7c is attached to an inner surface of an outer peripheral portion thereof. The stator 7b has a screw 7d on the lower surface of the fixed lower drum 2.
It is fixed by. Further, a coil 7e is formed on the lower surface side of the stator 7b so as to face the annular magnet 7c of the rotor 7a at a predetermined interval.

The rotary transformer 8 is fixed to the lower rotary drum 2 so as to face the rotor transformer 8a fixed to the upper rotating drum 5 at a predetermined interval in the axial direction. And a stator transformer 8b. Rotor transformer 8
a is electrically connected to the magnetic head 6 via connection means (not shown). As a result, when the upper drum 5 is driven to rotate, a video signal or the like to be recorded is supplied to the magnetic head 6 via the rotary transformer 8 for recording, and a reproduction signal from the magnetic head 6 is transmitted to the rotary transformer 8. And played back through the device.

According to the rotary magnetic head device 1 configured as described above, the rotating upper drum 5 is rotated around the rotating shaft 4 with respect to the fixed lower drum 2 by the motor 7 during reproduction. At the same time, when the magnetic tape T runs along the tape lead portion 2c of the fixed lower drum 2, a signal detected by the magnetic head 6 provided on the rotary drum 5 is output to the outside via the rotary transformer 8. Is done.
Further, at the time of recording, an electric signal from a control circuit or the like (not shown) is output to the magnetic head 6 via the rotary transformer 8, and writing to the magnetic tape T is performed.

The rotary magnetic head device 9 shown in FIG.
Is configured as a fixed shaft type, and has a fixed lower drum 2 having a substantially cylindrical outer shape, a fixed shaft 9a fixed in the fixed lower drum 2 by press fitting or the like, and a fixed shaft 9a.
, A rotating drum 5 having a substantially cylindrical outer shape and rotatably supported around the center line of the fixed lower drum 2 by the bearing 9b, and the fixed lower drum 2 and the rotating upper drum 5. The magnetic head 6 includes a magnetic head 6 attached to the upper rotating drum 5 so as to protrude outside the outer peripheral surface from between the drums 5, and a motor 7 and a rotary transformer 8 incorporated therein. That is, the rotating magnetic head device 9
Is substantially the same as the rotary magnetic head device 1 shown in FIG. 3 except that the rotating upper drum 5 is rotatably supported on the fixed lower drum 2 via a fixed shaft 9a and a bearing 9b. The operation is almost the same.

[0008]

In the rotary magnetic head devices 1 and 9 having such a structure, the lead height, that is, the mounting of the tape lead portion 2c formed on the outer peripheral surface of the lower fixed drum 2 to the mechanical deck is performed. The height A is determined by the fixed lower drum 2. Therefore, when the lead height is changed, it is necessary to newly manufacture a mold for molding the fixed lower drum 2, and a jig and a tool at the time of assembly are required in accordance with the new fixed lower drum 2. Need to change. On the other hand, the fixed lower drum 2 includes a rotary transformer 8.
Since the stator transformer 8b needs to be incorporated, its shape is complicated. Therefore, there is a problem that when a mold for the fixed lower drum 2 is newly manufactured, the manufacturing cost becomes extremely high. Further, when the tape lead portion 2c is worn out, it is necessary to replace the entire lower fixed drum 2, so that there is a problem that maintenance cost is increased. On the other hand, a method of cutting the reference mounting surface of the fixed lower drum 2 with respect to the mechanical deck is also possible. There was a problem that was not.

In view of the above, it is an object of the present invention to provide a rotary magnetic head device capable of changing the lead height of a tape lead portion of a fixed drum at a low cost with a simple structure. .

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a stationary drum, a rotating drum rotatably supported by a shaft with respect to the stationary drum, and a rotating drum mounted on the rotating drum. A magnetic head attached so as to protrude from the outer peripheral surface, wherein the side edge of the magnetic tape abuts against a tape lead portion provided as a step on the outer peripheral surface of the fixed drum, whereby the magnetic tape Wherein the fixed drum comprises: a base portion rotatably supporting the rotary drum via the shaft; and a tape lead portion fixedly held to the base portion. And a separate drum section defining an outer peripheral surface including the outer peripheral surface.

According to the above construction, the fixed drum is composed of the base for rotatably supporting the rotary drum via the shaft, and the drum fixed and held to the base. Since the tape lead portion for determining the lead height is formed on this drum portion, when changing the lead height, it is sufficient to replace the drum portion with the tape lead portion having the desired lead height formed on the drum, The parts will be commonly used. Here, for example, a stator transformer of a rotary transformer for transmitting a signal to a magnetic head is attached to a base portion of a fixed drum, so that the drum portion has a simple shape including a tape lead portion. For this reason, the manufacturing cost of only the drum portion is greatly reduced as compared with the manufacturing cost of a conventional fixed drum having a complicated shape in which the drum portion and the base portion are integrally formed.

Therefore, when the lead height is changed due to a user's request or the like, the tape height can be changed easily and at low cost by replacing only the drum portion of the fixed drum. . Also, if the tape lead of the fixed drum wears out with use,
By replacing only the drum portion of the fixed drum with a new drum portion, a new tape lead portion can be obtained without replacing the entire fixed drum, thereby reducing maintenance costs.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The embodiment described below is a preferred specific example of the present invention, and thus various technically preferable limitations are added. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIG. 1 shows the configuration of an embodiment of the rotary magnetic head device according to the present invention. The rotary magnetic head device 10 is used, for example, in an 8 mm VTR capable of magnetic recording and reproduction, and is fixed to the fixed lower drum 11 having a substantially cylindrical outer shape by shrink-fitting in the fixed lower drum 11. Fixed shaft 12, a bearing 13 fitted on the fixed shaft 12, and a rotating drum having a substantially cylindrical outer shape rotatably supported by the bearing 13 around the center line of the fixed lower drum 11. 14, a magnetic head 15 attached to the rotating drum 14 so as to protrude outside the outer peripheral surface from between the fixed lower drum 11 and the rotating upper drum 14, and a magnetic head 15 mounted near the upper end of the fixed shaft 12. Motor 16 and a rotary transformer 17 incorporated therein.

The fixed lower drum 11 has a tape running surface 11a on its outer peripheral surface, and its radius is
It is formed slightly smaller than the radius of one outer cylindrical surface 11b. As a result, a step, that is, a tape lead portion 18 is formed between the tape running surface 11a and the outer cylindrical surface 11b as shown in the figure. This tape lead section 18
Extends spirally along the tape running direction, that is, inclined with respect to a plane orthogonal to the central axis of the fixed lower drum 11. The rotating upper drum 14 is formed in a substantially hollow cylindrical shape whose upper end is open and whose lower end is closed, and has a bearing housing 14 a fitted on the bearing 13 at the center.

The magnetic head 15 is fixed on a head base 15a with an adhesive or the like, and the head base 15a is attached to the lower surface of the rotary drum 14 with screws 15b. The motor 16 includes a rotor 16a attached to the upper surface of the rotating upper drum 14, and a stator 16b fixed to the upper end of the fixed shaft 12 and facing the rotor 16a at a predetermined interval. Rotor 1
6a is formed in a dish shape, and is fixed on a bottom surface inside the rotating upper drum 14 by, for example, a screw 16c. Further, an annular magnet 16d is mounted on the upper surface of the rotor 16a. The stator 16b is fixed to the upper end of the fixed shaft 12. Further, the stator 1
6b, the annular magnet 1 of the rotor 16a
6d so as to oppose each other at a predetermined interval.
f is formed.

The rotary transformer 17 includes a rotating drum 1
4 and a stator transformer 17b fixed to the lower rotating drum 11 so as to face the rotor transformer 17a at a predetermined interval in the axial direction. I have. The rotor transformer 17a is electrically connected to the magnetic head 15 via connection means (not shown). Thus, when the rotating upper drum 14 is driven to rotate, a video signal or the like to be recorded is supplied to the magnetic head 15 via the rotary transformer 17 for recording, and a reproduction signal from the magnetic head 15 is transmitted to the rotary transformer 17. And played back through the device.

The above configuration is the same as that of the conventional rotary magnetic head device 9 shown in FIG. 4, but the rotary magnetic head device 10 according to the present embodiment is different in the following points. . That is, the fixed lower drum 11 is
As shown in FIG. 3, the fixed shaft 12 is supported, and the base portion 21 to which the stator transformer 17b of the rotary transformer 17 is attached by bonding or the like, and the outer peripheral portion of the fixed lower drum 11, that is, the tape running surface 11a, the outer peripheral surface 11b, and And a drum section 22 constituting the tape lead section 18.

The height of the tape lead 18 is selected so that the tape lead 18 has a predetermined lead height when the drum 22 is mounted on the base 21. Here, a plurality of types of drum units 22 having a tape lead unit 18 having various lead heights are prepared, and a drum unit of a type that provides an appropriate lead height according to a user's request. 22 is selected and attached to the base 21. In addition, the drum portion 22 is screwed to the base portion 21 or the like.
The lead height may be adjustable. In this case, the types of the prepared drum units 22 are reduced corresponding to the range in which the height can be adjusted.

The rotary magnetic head device 10 according to the present embodiment
Is configured as described above. At the time of reproduction, the rotating upper drum 14 is driven to rotate around the fixed shaft 12 with respect to the fixed lower drum 11 and the magnetic tape is By traveling along the lead portion 18, a signal detected by the magnetic head 15 provided on the rotating upper drum 14 is output to the outside via the rotary transformer 17. Further, at the time of recording, an electric signal from a control circuit or the like (not shown) is output to the magnetic head 15 via the rotary transformer 17, and writing to the magnetic tape T is performed.

Here, the fixed lower drum 11 has a drum portion 22 constituting an outer peripheral portion formed separately from a base portion 21 for fixedly holding the fixed shaft 12, and a stator transformer 17 b of the rotary transformer 17. Is attached to the base 21 by bonding or the like. Therefore, the drum section 22
The shape is simple, and the mold for molding is manufactured at a relatively low cost. Therefore, if a plurality of types of drum portions 22 having tape lead portions 18 corresponding to a plurality of lead heights are prepared, different lead heights can be obtained by a simple operation of replacing the drum portions 22 with different types. Of the rotating magnetic head device 10 will be constituted. For example, in place of the drum unit 22 shown in FIG. 1, as shown in FIG.
By attaching to the base portion 21, the lead height can be easily changed.

The rotating magnetic head device 1 configured as described above.
According to No. 0, when changing the lead height, it is only necessary to replace the drum part with a tape lead part having a desired lead height, and the base part is commonly used.
Therefore, when the lead height is changed due to a user's request or the like, the tape height can be changed easily and at low cost by exchanging only the drum portion having a simple shape among the fixed drums. Become. Also, if the tape lead of the fixed drum wears out with use,
By replacing only the drum portion of the fixed drum with a new drum portion, a new tape lead portion can be obtained without replacing the entire fixed drum, thereby reducing maintenance costs. When the drum part of the fixed drum is mounted on the base part so that the lead height of the tape lead part can be adjusted, the mounting height with respect to the base part is appropriately adjusted using one drum part. By doing so, the lead height can be changed, and the cost can be further reduced.

In the above-described embodiment, the drum portion 22 is fixed and held by being fitted to the base portion 21. However, the present invention is not limited to this.
You may make it fix to a base part 21 with a screw etc. so that height adjustment is possible. According to this configuration, each drum portion 22 corresponds to the mounting height with respect to the drum portion 22,
Since the lead height in the predetermined range is given, the types to be prepared are reduced as compared with the case where the mounting height cannot be adjusted. Further, in the above-described embodiment, the shaft supporting the rotating upper drum 14 is configured as the fixed shaft 12, but is not limited thereto, and is rotatable with respect to the bearing fixed to the fixed lower drum 11. It may be configured as a supported rotating shaft.

[0024]

As described above, according to the present invention, the lead height of the tape lead portion of the fixed drum can be changed at a low cost with a simple structure.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing the configuration of an embodiment of a rotary magnetic head device according to the present invention.

FIG. 2 is a schematic cross-sectional view showing a configuration provided with a drum section for giving different lead heights in the rotary magnetic head device of FIG. 1;

FIG. 3 is a schematic sectional view showing an example of a rotary magnetic head device provided with a conventional tape lead section.

FIG. 4 is a schematic sectional view showing another example of a rotary magnetic head device provided with a conventional tape lead section.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Rotating magnetic head device, 11 ... Fixed lower drum, 12 ... Fixed shaft, 13 ... Bearing, 14 ... Rotating upper drum, 15 ... Magnetic head, 16 ... Motor , 17 ... Rotary transformer, 18 ... Tape lead part, 21 ... Base part, 22, 22a ... Drum part

Claims (4)

[Claims] 1. A fixed drum, a rotary drum rotatably supported on the fixed drum via a shaft, and a magnetic head mounted on the rotary drum so as to protrude from an outer peripheral surface thereof. A rotating magnetic head device, wherein the magnetic tape is guided by a side edge of the magnetic tape abutting against a tape lead portion provided as a step on the outer peripheral surface of the fixed drum; A drum configured to rotatably support the rotating drum via the shaft; and a separate drum defining an outer peripheral surface including the tape lead fixed and held to the base. A rotating magnetic head device comprising: 2. The rotary magnetic head device according to claim 1, wherein the drum portion is attached to the base portion such that a lead height of the tape lead portion can be adjusted. 3. The rotary magnetic head device according to claim 1, wherein the shaft is fixed to the base portion and rotatably supports the rotary drum via a bearing. 4. The rotary magnetic head device according to claim 1, wherein said shaft is rotatably supported by said base portion via a bearing, and is fixed to said rotary drum.