JPH0210502A - Rotating magnetic head device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotating magnetic head device (cylinder device) of a helical scan magnetic recording/reproducing device, and particularly relates to a rotating magnetic head device (cylinder device) of a helical scan magnetic recording/reproducing device. The present invention relates to a rotating magnetic head device suitable for high-definition VTRs and digital VTRKs in which a cylinder rotates.

[Conventional technology]

Conventionally, in a rotating magnetic head device, when a signal or power is supplied to the rotating part via a slip ring and a brush, or when a signal is extracted from the rotating part, for example,
As described in Japanese Patent No. 9-129901, a slip ring is provided at the tip of a rotating shaft of a rotating part, and signals are sent and received by contact with a brush held on a fixed part.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, since it is necessary to provide a support structure for supporting the brush in the fixed part, the structure becomes more complicated and larger. Furthermore, since the contact portion between the brush and the slip ring is exposed, a separate dust-proof cover is not required, leading to problems such as an increase in the size of the device.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems of the prior art described above, to provide a brush that is small in size and simple in structure, provides a dustproof effect for slip rings and brushes without using a special dustproof cover, and provides a brush.

It is necessary to provide a rotating magnetic head device (cylinder device) in which slip rings and magnetic heads can be easily replaced.

[Means to solve the problem]

In order to achieve the above object, the rotating magnetic head device of the present invention has an upper cylinder and a lower cylinder fixed, a rotating cylinder with a rotating magnetic head mounted therebetween, and a slip ring and a brush attached to the fixed upper cylinder. Accommodate internal busyness.

Specifically, the brush is held in a brush holder, and the brush holder is directly fixed to the inner surface of the top plate of the upper cylinder. Opposed to this brush, a slip ring is provided on the central axis (shaft) that supports the rotating cylinder on which the rotating head is mounted. These brushes and slip rings are located within the upper cylinder intermediate the top plate of the upper cylinder and the rotating cylinder.

As a preferred invention, the diameter of the central axis (shaft) is smaller in the portion where the slip ring is fitted than in other portions (lower portions).

A hole is drilled in the top plate of the upper cylinder, and a jig is inserted through this hole when assembling the upper cylinder. When installing the upper cylinder with a brush, this jig removes the brush from the slip ring. Pull apart.

As a preferred invention, the central shaft is configured to be rotatable together with the rotating cylinder, an upper cylinder support is supported on the upper part of the rotating central shaft via a bearing, the upper cylinder is fixed to the upper cylinder support, and the upper cylinder is fixed to the upper cylinder support. Secure with a stopper to prevent rotation.

The rotary cylinder is fixed in such a way that it is tightly fitted into the disk attached to the central shaft, and the diameter of the fitting portion between the disk and the rotary cylinder is also made larger (than the outermost diameter of the upper cylinder holder).

[Effect]

The operation based on the above configuration will be explained.

The brush holder is attached to the inner surface of the top plate of the fixed upper cylinder to accommodate the internal pressure of the brush and slip ring, so there is no need to provide a special dust cover, and the dust prevention effect of the slip ring and brush is improved. is obtained, making it possible to downsize the cylinder device.

By making the diameter of the center shaft thinner at the slip ring than at other parts, the original mechanical strength of the center shaft is maintained!
1, the peripheral speed of the pickpocket and bling surface that comes into contact with the brush can be reduced to extend its life.

By providing a hole in the top plate into which a jig can be inserted, when installing the upper cylinder, the jig was used to separate the brush from the slip ring provided on the central shaft, so the brush could rub against the slip ring. This will prevent the brush from becoming damaged or bent.

In the invention in which the central shaft rotates together with the rotating cylinder, there is no need to interpose a bearing or the like between the rotating shaft and the rotating cylinder and slip ring, and these rotating cylinders and slip rings are fixed on the central axis. Since the slip ring can be mounted in close relation, it is possible to reduce the diameter of the slip ring. In addition, by making the diameter of the fitting part between the rotating cylinder and the disk larger than the outermost diameter of the upper cylinder receiver, when replacing the rotating magnetic head, you can simply remove the upper cylinder without removing the upper cylinder receiver. The rotating cylinder or the rotating magnetic head can be pulled out of the device by slipping through the upper cylinder receiver, and replacement work can be easily performed.

〔Example〕

FIG. 1 shows the structure of a rotating magnetic head device according to an embodiment of the present invention.

1 is a fixed lower cylinder, and a shaft 4 is fixed at the center by means such as press fitting. Although not shown, a spiral lead (tape guide) is formed on the outer periphery of the lower cylinder as is well known, and guides the magnetic tape in a spiral manner.

A disk 6 is rotatably supported on the shaft 4 by an upper bearing 7 and a lower bearing 8. The rotation of the disk B is driven by a built-in motor. A motor rotor magnet 16 fixed to a yoke 17 is attached to the disk 6 with screws 18.

The stator coil 15 of the motor is attached to the stator yoke 14 and fixed to the lower cylinder 1.

20 is attached to the 9FG'B-ri 19 using an FG magnet, and is attached to the disk 6 by screws 21.

22 is an FG coil, which is supported by a holder plate 25;
It is fixed to the lower cylinder 1.

A rotary cylinder 3 is attached to the disk 6 by a screw 11. A rotating magnetic head 10 attached to a helad base 10a is fixed to the rotating cylinder 3. The head base 10a is attached to the rotating cylinder 3 with screws 9. As is well known, a rotating magnetic head 10 scans a magnetic tape to record and reproduce signals.

Numeral 26 is a stopper for applying preload to the bearings 7 and 8, and is fixed to the shaft 4 with the set screw 5 while applying preload to the bearings.

The shaft 4 has a narrow diameter at the top, making it a so-called stepped shaft, and the upper cylinder 2 is attached to the top with a set screw 27.
yoυ, shirt) is fixed at 4.

A slip ring 24 is fixed to the upper part of the disk 6 by a screw 25, and rotates together with the disk 6. The brush 28 is supported by a brush holder 29 and contacts the slip ring 24 to transmit and receive electric signals and power.
It is attached to the upper cylinder 2.

The reason why the diameter of the shaft 4 is made thinner at the upper part is to make the outer diameter of the slip ring 24 fitted therewith as small as possible. Since the life of a slip ring is long due to its low circumferential speed, it is necessary to make the outer diameter as small as possible.

Since the force applied to the upper cylinder 2 is usually only the force from the tape and is not large, the performance is not affected even if the diameter of the upper part of the shaft 4 is made small as shown in the figure.

Signals from the rotating magnetic head 10 are connected to a preamplifier 32 fixed to the rotating cylinder 6 via a lead wire 51 from the helad base 10a. On the other hand, the signal from the slip ring 24 is connected to the preamplifier via a relay board 33 and a lead wire 34. In this embodiment, the signals supplied from the brush 32 and the slip ring are the power supply of the preamplifier,
These include ground, switching signals for the plurality of rotating magnetic heads, etc.

Signals recorded on or reproduced from magnetic tape (
The output signal of the preamplifier 32) is supplied to or taken out from the outside via the rotary transformer rotor 12 and the rotary transformer stator 13.

Although not shown in the figure, the connection from the rotating magnetic head 10 to the rotary transformer rotor is accomplished by making a through hole in the disk 6 and passing a lead wire through it.

FIG. 2 is one cylinder, and as described above, the brush holder 29 is attached to the upper cylinder from below with the screw 30, and the brush 28 is in contact with the slip ring 24.

Reference numeral 35 denotes a lead wire sb for connecting the brush and the cylinder external circuit, and the lead wire sb exits to the outside through a lead hole 36 formed at the top of the upper cylinder. 37 is also a small hole drilled in the upper part of the upper cylinder 2. This hole fixes the upper cylinder 2 and brush 28 assembly to the shaft 4, and is a hole for inserting a jig when assembling the cylinder.As is well known, the brush contacts the slip ring with a certain amount of contact pressure. Because I am
When the upper cylinder and brush are assembled and not in contact with the slip ring, the slip ring contact point of the brush is located closer to the center axis than the outer periphery of the slip ring. If you insert the upper cylinder brush assembly from above in this state, the brush will rub against the slip ring and move.
The brush may be permanently deformed. In the present invention, the small hole 37
Insert a jig such as a round bar and elastically deform the brush so that the contact point of the brush is located further from the center axis than the outer diameter of the slip ring, and then insert the upper cylinder brush assembly in the axial direction. However, by removing the jig once the brush has been fixed to the shaft, excessive force is not applied to the brush and permanent deformation is prevented. It is clear from the above that it is also possible to omit the lead hole 36 and pass the lead wire 35 through the small hole 37.

Next, still another embodiment of the present invention will be described based on FIG. In the embodiment shown in FIG. 1, the shaft 4 was fixed and did not rotate, but in the embodiment shown in this figure, the shaft 37 is a rotating shaft.

Bearings 7 and 8 are arranged above and below in the lower cylinder 38.
, the shaft 37 rotates while being supported by these. A disk 59 is fixed to the shaft 37 by means such as press fitting. 49 is a stopper for applying preload to the bearings 7 and 8; 69
, is fixed to the shaft 37 with a preload applied to the bearing. A yoke 50 is screwed to the stopper 49.

A rotor magnet 48 of the motor is bonded to the yoke 50. Further, a stator coil 47 attached to a stator yoke 46 is fixed to the lower part of the lower cylinder 38, and this part constitutes a motor, which rotates a shaft 57 feet.

A rotating cylinder 40 is screwed to the disk 39, a piezoelectric bimorph 58 is fixed to the rotating cylinder, and a rotating magnetic head 10 is attached to the tip of the piezoelectric bimorph 58.

At the tip of the shaft 37, an upper cylinder receiver 54 is supported by two bearings 52 and 53. A slip ring 41 is provided between the bearing 52 and the disc 39 and is screwed to the disc 39. The bearings 52 and 53 are fixed so as not to move in the axial direction by a stopper 55 fixed to the shaft 37 with a set screw.

The upper cylinder 51 is screwed to the upper cylinder receiver 54. In this state, the upper cylinder 51 rotates as the shaft 37 rotates.

Reference numeral 56 denotes a locking pin to prevent this from rotating.The pin 56 is attached to the tip of a support member 57 fixed to a fixed part, and is inserted into a hole 61 provided in the upper cylinder 51 to prevent the rotation of the upper cylinder 51. is prevented. Therefore, the upper cylinder receiver 54 does not rotate either. The brush holder 43 is fixed to the upper cylinder receiver 541C, and the brush 42 is attached to the brush holder 43 and is in contact with the slip ring 41. A lead wire 59 is connected from the piezoelectric bimorph 58 to a relay board 60, where it is connected to a slip ring. The piezoelectric bimorph drive signal from the fixed part is supplied to the piezoelectric bimorph 58 through the brush 42, slip ring 41, relay board 60, and lead wire 59' 1 ft. This causes the tip of the piezoelectric bimorph to displace in the vertical direction and display the image. It is used for special playback (noiseless search, noiseless slow noiseless still) in signal playback, or auto tracking. The recording/reproducing signal is supplied from the outside or taken out from the outside by the rotary transformer rotor 44 and rotary transformer stator 45, although connections are not shown in the figure.

In the embodiment shown in FIG. 3, the diameter of the fitting portion of the disc 59 and the rotary cylinder 40 is made smaller than the outermost diameter of the upper cylinder receiver 54 and the diameter of the part farthest from the central axis of the brush holder 43. It's getting bigger. Therefore, when replacing the head, the rotating disk 40 can be removed by removing the upper cylinder 51t from the upper cylinder receiver 54, removing the set screw of the rotating disk, removing the lead wire if necessary, and pulling it straight upward. I can do it.

Attachment is possible by reversing the above steps, and head replacement is extremely easy. Upper cylinder receiver 54 and upper cylinder 5
By creating the fitting part 62 of 1 with high precision, it is possible to obtain reproducibility of the position and orientation when the upper cylinder 51 is removed and reattached. This makes it extremely easy to replace the head with ease and high precision.

In the above embodiment, the outer circumferential surface of the rotating cylinder has the same diameter as the outer circumferential surfaces of the lower cylinder and the upper cylinder, and the diameter of the rotating cylinder is made smaller so as to contact the tape.
It is clear that the present invention is also applicable to a format in which only the rotating magnetic head 10 is in contact with the tape.

〔Effect of the invention〕

As explained in detail above, according to the rotating magnetic head device of the present invention, the brush holder is attached to the inner surface of the top plate of the fixed upper cylinder, and the brushes and slip ring are housed inside the upper cylinder. This eliminates the need for a special mechanism for mounting the brush mechanism or a separate dust-proof cover for brushes, pickpockets, and pullers, allowing the upper cylinder itself to have a dust-proofing function, making the entire device more compact. It is possible to do so.

In addition, even when high voltage is applied, there is no risk of accidental touching, and other excellent effects are achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the rotary magnetic head device of the present invention, and FIG. 2 is a bottom view of the upper cylinder portion. FIG. 6 is a sectional view of another embodiment of the rotary magnetic head device of the present invention. . 1.38...Lower cylinder 2.51...Upper cylinder 3.40...Rotating cylinder 4.67...Shaft (center axis) 6.39...Disk 10...Rotating magnetic head 12 .44... (rotary transformer) rotor 15.
45...(rotary transformer) stator 14.46
... (motor) stator yoke 15.47 ... (
(motor) stator coil 16.48...(motor) rotor magnet 24.41...slip ring 28, 42...brush 29.45...brush holder 54...upper cylinder receiver 56...・Bin (stopper) No. IL ¥1

Claims (1)

[Scope of Claims] 1. A rotating magnetic head for a magnetic recording and reproducing device, which includes a fixed upper cylinder and a lower cylinder, a rotating cylinder that rotates with a rotating magnetic head mounted thereon, and a central shaft that supports the rotating cylinder. 1. A rotating magnetic head device, characterized in that a slip ring and a brush for supplying electric signals or power to a rotating part from the outside are housed inside an upper cylinder. 2. The rotary magnetic head device according to claim 1, wherein a brush holder for holding the brush is directly fixed within the upper cylinder. 3. The rotary magnetic head device according to claim 1, wherein the diameter of the slip ring fitting portion of the central shaft is smaller than the diameter of a lower portion thereof. 4. The rotary magnetic head device according to claim 1, wherein a hole is formed in the upper cylinder into which a jig for deforming the brush and separating it from the slip ring is inserted when the upper cylinder is assembled. 5. The central shaft is configured to be rotatable together with the rotary cylinder, an upper cylinder support is supported on the upper part of the central shaft via a bearing, the upper cylinder is fixed to the upper cylinder support, and the rotation of the upper cylinder is The rotary magnetic head device according to claim 1, further comprising a stopper member for stopping. 6. The rotating magnetic head device according to claim 5, wherein the brush holder is fixed to the upper cylinder receiver. 7. The rotary cylinder is fixed by fitting into a disk attached to the central shaft, and the diameter of the fitting portion of the disk and the rotary cylinder is made larger than the outermost diameter of the upper cylinder receiver. 6. The rotating magnetic head device according to item 5.