JPH0677281B2 - Rotating head device - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a rotary head device used in a magnetic recording / reproducing apparatus and the like, and in particular, corresponds to a rotary transformer having a large diameter and a drum having a small diameter due to the increase in the number of channels. In addition, the present invention relates to a rotary head device having a structure suitable for performing head replacement work with good workability.

[Background of the Invention]

A conventional rotating drum structure of a magnetic recording / reproducing apparatus is disclosed in Japanese Patent Laid-Open No.
As in the drum structure described in Japanese Patent Laid-Open No. 150125 (see FIGS. 1 to 4 of the same publication), the rotor magnet of the motor and the rotary transformer are directly fixed to the rotating disk. A rotating body equipped with a head engages with the disk and is screwed. However,
In the future, in order to cope with digital signal recording / reproduction, multi-channel division recording is considered, and it is inevitable to increase the diameter of the rotary transformer for transmitting signals. In addition, in order to miniaturize the VTR, a system with high-speed rotation of a small diameter cylinder is required. However, the drum structure shown in FIGS. 1 to 4 of the above publication cannot achieve the above-mentioned essential problems. That is, there is no space for joining the disk on which the rotor portion of the motor that drives the drum is mounted and the rotor portion of the rotary transformer.

As a countermeasure against this, a structure in which a rotary drum equipped with a head and a rotor portion of a rotary transformer are bonded and integrated is conceivable. However, with this structure, in the head replacement work, the rotor unit on which the head is mounted must be replaced together with the rotating body.
Since it is necessary to set the posture and the mounting phase angle between the heads, it is not possible to replace the head alone in the field where there is no jig.

Further, if the rotating body to which the rotor portion of the rotary transformer is adhered is replaced, the following harmful effects occur. That is, the rotary transformer has a large variation in thickness due to its manufacturing method. Further, when the bonding to the rotating body is performed by adhesion, the thickness between the lower surface of the rotating body on which the head is mounted and the upper surface of the rotor portion of the rotary transformer are overlapped due to variations in the thickness of the adhesive layer.
It will vary greatly. In this situation,
The gap between the rotor and stator of the rotary transformer is
Since the video signal must be set narrow (on the order of several tens of microns) for efficient transmission, the thickness variation causes a problem that the rotary transformer contacts or the signal transmission efficiency decreases due to a large gap. Will be invited. For this reason, it is necessary to finely adjust with a spacer or the like in order to secure the specification gap, and there is a problem that the head replacement work is complicated and the cost is high.

[Object of the Invention]

The object of the present invention is to ensure reproducibility in head replacement work without re-adjusting and setting the gap between the rotor part and the stator part of a rotary transformer that transmits a video signal, except for the drawbacks of the prior art. Accordingly, it is possible to provide a rotary head device having a structure that contributes to improvement in assemblability and accuracy.

[Outline of Invention]

To achieve the above object, in the present invention, in a rotary head device having a rotary transformer that is attachable to and detachable from a rotating portion including a head, the attaching means is tightened on an outer peripheral side surface portion of the rotating portion. The structure has a structure.

Example of Invention

The present invention will be described below with reference to FIGS. 1 to 5. First, the structure and configuration of the figure will be described, and then the operation will be described.

FIG. 5 is a schematic plan view of a magnetic recording / reproducing device for explaining the rotary head device according to the present invention. In the figure,
1 is a drum part, 2 is an inclined pin, 3 is a guide roller, 4 is a voice head, 5 is a capstan, 6 is a pinch roller, 7
Is an erasing head, 8 is a fixed guide, and 9 is a tension pin. The tension arm and the control mechanism member are not shown. 10 is a fixed guide, 11 and 12 are fixed guides in the cassette case, 13 is a supply reel section, and 14 is a winding reel section. The reel stand that engages with the reel portion is not shown. Reference numeral 15 is a cassette, and 16 is a magnetic tape (hereinafter referred to as tape).

The tape 16 wound around the supply reel portion 13 contained in the cassette 15 slides in contact with each guide member and the drum portion 1, and is driven by the capstan 5 and the pinch roller 6 at a constant speed in the arrow B direction. It is stored in the take-up reel unit 14. The tape 16 is controlled by the tension pin 9 and a tension control member (not shown) so that the tape tension is constant at the beginning and the end of the winding of the cassette.

In the drum unit 1 , a rotating body on which a plurality of video heads (not shown) for magnetic recording and reproduction are mounted rotates in the direction of arrow A.

FIG. 1 is an explanatory view of the principle of the rotary head device of the present invention. In the figure, 17 is a lower fixed drum, 18 is a fixed shaft, 19 is an upper fixed drum, 20 is a disk, 21 is a bearing, 22 is a middle rotating drum, 23 is a holding plate, 24 is a preload metal fitting, 25 is a magnet holding plate, 26 is a magnet, 27 is a winding portion, 28 is a stator yoke, 29 is a rotor portion of a rotary transformer, 30 is a stator portion of a rotary transformer, 31 is a height adjusting spacer, 32 is a tack magnet, 33 is a tack sensor, 34 Is an upper fixed drum fixing screw, 35 is a preload metal fixing screw, 36 is a rotary drum fixing screw, 37 is a holding plate fixing screw, 38 is a step adjusting screw, 39 is a head base, 40 is a head base fixing screw screw,
41 is a holding plate screw, 42 is a head, 43 is a signal line, 44 is a voltage applying line, and 45 is a video signal line.

Next, the configuration of the drum will be described. The fixed shaft 18 is press-fitted vertically into the lower fixed drum 17, and is fitted with a disk 20 having two bearings 21 built therein. The medium rotating drum 22 is fixed to the disk 20 by a rotating drum fixing screw 36.
On the upper surface of the middle rotating drum 22, a holding plate 23 to which a rotor portion 29 of a rotary transformer is adhered is fixedly mounted by a holding plate fixing screw 37. A head base 39 to which a head 42 is adhered is fixedly mounted on the middle rotating drum 22 by a plurality of head base fixing screws 40 (only one is shown). Further, a step adjusting screw 38 is provided for each position of the head.

In the motor that drives the disk 20 and the intermediate rotating drum 22, the rotor portion is configured by a magnet holding plate 25 to which a magnet 26 is adhered being fixed to the disk 20 by a holding plate screw 41, and the stator portion is a winding wire. A stator yoke 28 to which the portion 27 is bonded is bonded to the lower fixed drum 17 with concentric accuracy. The preload metal fitting 24 that fits smoothly with the fixed shaft 18 is screwed to the fixed shaft 18 while preloading the inner ring of the bearing 21 with the preload metal fitting fixing screw 35. The stator section 30 of the rotary transformer is an upper fixed drum.
The thickness of the height adjusting spacer 31 is adjusted so that the gap between the rotor and the rotor portion 29 of the rotary transformer is several tens of microns. The height of the upper fixed drum 19 is restricted by a height adjusting spacer 31, and the upper fixed drum 19 is fixed to the fixed shaft 18 by an upper fixed drum fixing screw 34. The tack magnet 32 is embedded in the disc 20. The tack sensor 33 is fixed to the lower fixed drum 17, and the detection signal thereof is taken out through a signal line 43.

Next, the operation of the drum will be described. When a voltage is applied to the voltage application line 44 of the motor stator section, the winding section 27 is excited and the disk 20, the intermediate rotating drum 22 and the like rotate integrally.
The absolute position of the head 42 is obtained by detecting the magnetic field generated by the tack magnet 32 with the tack sensor 33. Head 42
The video signal recorded / reproduced by is transmitted by the rotary transformer (the rotor section 29 and the stator section 30) and is transmitted to a video circuit (not shown) via the video signal line 45.

Next, the assembly will be described with reference to FIGS. 1 and 2. Note that, in FIG. 2, the parts of the lower fixed drum and the motor section are omitted. In FIG. 3, the rotor portion 29 of the rotary transformer is bonded to the holding plate 23. A plurality of heads 42 (only one is shown) are fixed at predetermined positions on the middle rotating drum 22 by head base fixing screws 40 and screw holes 22b provided on the middle rotating drum 22. Also the head
The lead wire from the winding wire of 42 is drawn out by an L-shaped hole 22c provided in the middle rotating drum 22 as shown in the section AA,
It is connected to the rotor unit 29 of the rotary transformer (the connection state is not shown). The middle rotating drum 22 is fixed to the disk 20 through the through hole 22a by the rotating drum fixing screw 36. The holding plate 23 is fixed to the middle rotating drum 22 through the through hole 23a by the holding plate fixing screw 37.

The disk 20 on which the above-mentioned rotating body is mounted fits with the fixed shaft 18 shown in FIG. 1 and is preloaded by the preload metal fitting 24 in order to regulate the vertical direction.
Is fixed to the fixed shaft 18 by.

Next, in order to secure a gap between the stator portion 30 and the rotor portion 29 of the rotary transformer at a predetermined value (of the order of several tens of microns), the height adjusting spacer 31 connects the upper fixed drum 19 and the preload metal fitting 24. Inserted in between. After this, the upper fixed drum fixing screw 34 is fixed to the fixed shaft 18.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. The structure of this embodiment has a multi-channel structure, and is suitable even when the rotary transformer becomes large.

FIG. 3 is a vertical sectional view of the drum of the embodiment, and FIG. 4 is an assembly drawing thereof. The basic structure of this embodiment is the same as the structure shown in FIGS. 1 and 2, but the shape of the holding plate 47 and the middle rotating drum 46 for holding the holding plate 47 is different. That is, the holding plate 47 has a convex portion 47b having a through hole 47a formed therein, and the convex portion 47b engages with the notch surface 46b of the middle rotating drum 46 whose side surface is notched. Also,
The cutout surface 46b is provided with a screw hole 46c, and the holding plate 47 is fixed to the intermediate rotating drum 46 by a fixing screw 48.

Finally, the absolute height of the head is adjusted by providing the notch 19a in the upper fixed drum 19 so that the upper fixed drum 19 does not have to be removed from the fixed shaft 18 in both the first and second embodiments. It can be performed by rotating the step adjusting screw 38 using a hexagon wrench.

〔The invention's effect〕

According to the present invention, the rotary transformer unit can be independently attached to and detached from the rotating unit including the head, so that the work efficiency of replacing the rotating head can be significantly improved.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention, FIG. 2 is a perspective view of the configuration of FIG. 1, FIG. 3 is a sectional structural view of an embodiment of the rotary head device of the present invention, and FIG. 4 is of FIG. FIG. 5 is a schematic perspective view of the structure of the magnetic recording / reproducing apparatus. 1 …… Drum part, 17 …… Lower fixed drum, 18 …… Fixed shaft,
19 …… Upper fixed drum, 20 …… Disc, 21 …… Bearing, 22
...... Middle rotating drum, 23 …… Holding plate, 24 …… Preload metal fitting, 25
...... Magnet holding plate, 26 ...... Magnet, 27 ...... Winding section, 28 ...... Stator yoke, 29 ...... Rotary transformer rotor section, 30 ...... Rotary transformer stator section, 31 ...
… Height adjustment spacers, 32… Tuck magnets, 33…
… Tack sensor, 38 …… Step adjustment screw, 39 …… Head base, 42 …… Head, 43 …… Signal plate, 44 …… Voltage application line, 45 …… Video signal line, 46 …… Middle rotating drum, 47 …… Holding plate.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideyuki Fukuda, Inventor, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside the Home Appliance Research Laboratory, Hitachi, Ltd. (72) Inventor Saburo Kazama, 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa (56) References Japanese Patent Laid-Open No. 55-150125 (JP, A) Jitsuko Sho 48-38167 (JP, Y1)

Claims (2)

[Claims] 1. A rotary head device having a rotary transformer that is attachable to and detachable from a rotating portion including a head by a mounting means, wherein the mounting means has a tightening structure on an outer peripheral side surface portion of the rotating portion, A rotary head device, characterized in that a rotary side member of a rotary transformer is attached to the rotary part side. 2. The rotary head device according to claim 1, wherein the rotary portion is configured such that a portion where the tightening structure is provided is formed at a smaller radial position than a circumferentially adjacent portion thereof. .