JPS63268102A - Rotary head device - Google Patents

Abstract

PURPOSE:To obtain a miniaturized device by arranging a first coil at a first core to constitute a rotor and a second coil at a second ore to constitute a stator and constituting a rotary transformer for one channel by means of both. CONSTITUTION:Coils 32 and 33 to constitute two heads are serially connected, coils 13 and 14 as a rotary transformer are buried to a core 11 of respective rotors and a core 11 of a stator and only one channel is obtained. As the result, a current to flow at the coil 32 also flows at the coil 33. However, in an R-DAT, two rotary heads separated to 180 deg. are not contacted to a magnetic tape by 90 deg. only respectively, and when one side head is used, other head is not used without fail. Consequently, by time-dividing the input output of the rotary transformer for one channel, the signal can be recorded and reproduced in the same way as the case of two channels. Thus, the diameter of the rotary transformer, consequently, the diameter of a rotary drum 3 can be made smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotary head device suitable for use in a magnetic recording/reproducing device typified by R-DAT.

[Summary of the invention]

In the present invention, signals are sent and received by using a rotary transformer for substantially one channel on a time-sharing basis between a pair of rotary heads separated by 180 degrees from each other.

[Background technology]

FIG. 15 shows the configuration of a rotary head device of a conventional magnetic recording/reproducing device such as a video tape recorder or R-DAT. In the figure, 1 is a shaft rotated by a motor (not shown), and a flange 2 is fixed thereto. 3
is a rotating drum, which is fixed to the flange 2 with washers 5 and screws 4. 6 is a head, which is fixed to dime 7. The dime 7 is fixed to the rotating drum 3 together with a dime base plate 19 by screws 8 and washers 9.

Reference numeral 10 denotes a screw, which is screwed onto the rotating drum 3.

By rotating this screw 10 and moving it forward and backward, it is possible to press the dime 7 and adjust the height position of the head 6. The flange 2 has a core 11 with a coil 13.15.
is fixed with adhesive. Coil 14 facing core 11
．． A core 12 having a diameter of 16 is fixed to a stationary drum 17. The fixed drum 17 is attached to the shaft 1 so as not to rotate integrally therewith. The rotor is made up of core 11 and coil 13.15, and core 12 and coil 14.
．． 16 constitutes a stator, and both constitute a rotary transformer. The head 6 is electrically connected to the coil 13 (or 15) via a dime board 19 or a relay board 18.

FIG. 16 shows the structure of the head 6. The pair of cores 21 are arranged to face each other so that one end forms a magnetic gap 22 . Further, the other ends 23 of the cores 21 are connected to each other, and the cores 21 form a closed magnetic path. Furthermore, a coil 24 connected to the coil 13 (or 15) is wound around the core 21.

When the shaft 1 rotates, the rotating drum 3, head 6, core 11. Coils 13.15 rotate together. Magnetic flux from a magnetic tape (not shown) flows into one core 21 from the magnetic gap 22, flows to the other core 21, and flows out from the magnetic gap 22.

Therefore, an electromotive force is generated in the coil 24, and a signal flows to the coil 13 (or 15). This reproduction signal is output to a circuit (not shown) via the other coil 14 (or 16) constituting the rotary transformer.

Although not shown, there is another opening 180 degrees apart from the head 6.
Two heads are attached, and the reproduction output thereof is similarly supplied to an external circuit via coil 15 (or 13) and coil 16 (or 14).

When recording a signal, current flows in the opposite path to that described above.

[Problem that the invention seeks to solve]

In this way, the conventional rotary head device has one coil for two channels in the rotary transformer corresponding to one pair of heads 6.
3.14, 15, and 16 so that signals can be sent and received simultaneously to each head 6 independently, there is a drawback that the diameter of the core 11.12, and therefore the rotating drum 3 and fixed drum 17, becomes large. .

Therefore, the present invention realizes a smaller rotary head device.

[Means for solving problems]

The present invention provides a rotary head device including a first core constituting a rotor, and a first coil disposed in the first core so as to constitute a part of a rotary transformer for substantially one channel. , a pair of heads spaced apart by 180 degrees from each other and connected together to a first coil, and a second core forming a stator.

It is characterized by comprising a second coil disposed in the second core so as to constitute, together with the first coil, a part of a rotary transformer for substantially one channel.

[Effect]

A first coil is disposed in a first core constituting a rotor, and a second coil is disposed in a second core constituting a stator, and the two substantially constitute a rotary transformer for one channel. .

A pair of heads 180 degrees apart are connected together to the first coil. Transmission and reception of signals to and from the pair of heads is performed by using the second coil in a time-sharing manner.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

In the following figures, the same reference numerals are given to the parts corresponding to those in the above case, and detailed description thereof will be omitted.

1 to 3 show a first embodiment of the invention. In this embodiment, a protruding portion 31 that protrudes toward the outer periphery is integrally molded onto a core 11 constituting a rotor of a rotary transformer. Part of the coil 13 of the rotary transformer is extended as it is to both sides to form coils 32 and 33 that constitute the magnetic head. That is, the coil 32 and the coil 33 forming a pair of heads separated by 180 degrees from each other are connected in series to the coil 13. The coils 32 , 33 are placed on the projection 31 . Therefore, in this state, coil 1 as a rotary transformer
3 and coils 32 and 33 serving as magnetic heads are located on substantially the same plane.

Coil 32 (as well as coil 33) has two loops 41, 42 as shown in FIG. Loops 41 and 42 occur when current flows through the coil 32.

The coils are wound so that the magnetic flux output from one loop and the magnetic flux output from the other loop are in opposite directions in FIG. A head chip 50 as shown in FIGS. 4 to 6 is bonded and fixed onto the coils 32 and 33 as shown in FIG. 3.

The head chip 50 is composed of a pair of cores 51 and 52 made of ferrite or other magnetically permeable material.
1.52 are arranged to face each other so that a part thereof constitutes a magnetic gap 53. However, the portions of the cores 51 and 52 other than the magnetic gap 53 are sufficiently separated to prevent magnetic flux from flowing directly between them. In order to more effectively prevent this direct inflow and outflow of magnetic flux, a member 54 made of a non-magnetic material such as glass, metal, ceramic, etc. is filled between the cores 51 and 52 as necessary (fourth
Alternatively, a conductive plate 61 made of metal, foil, conductive paint, etc. is arranged on the core 51, 52 to reduce upward leakage magnetic flux due to eddy current (Fig.
Figure 5). The head chip 50 is attached with a conductive adhesive 62.
．． A similar effect can be achieved by adhering and fixing the coil 32 onto the protrusion 31 (FIG. 6).

Therefore, as shown in FIG.
1 flows through the core 51, flows out from the core 51, and flows into the protrusion 31 as a bridge core (B).The magnetic flux (B) that flows from the protrusion 31 flows into the protrusion 3
1, flows out from the joint surface of the core 52, and flows into the core 52 (C), the magnetic flux that flows into the core 52 (C) flows inside the core 52, and flows out from the magnetic gap 53 (D).
A loop 41 is arranged in the magnetic flux (CB) path flowing out from the core 51 and flowing into the protrusion (bridge core) 31, and a loop 42 is placed in the magnetic flux (C) path flowing out from the protrusion 31 and flowing into the core 52. It is located. Therefore loops 41 and 42
The electromotive force generated in is added, and a current flows through the coil 32. Since the extended end of the coil 32 is the coil 13, the current in the coil 32 flows directly to the coil 13, and a corresponding current is output from the coil 14 forming the rotary transformer.

In the figure, the number of turns of the coils 13, 14, 32, and 33 is 1 turn, but it is of course possible to have 2 turns or more. Further, these coils can be formed using ordinary conductive wires, but since so-called winding work is not required, they can also be formed by printed coils, metallization, sheet metal punching, etc. In the case of the latter three, there is no need for wiring work.

FIG. 7 shows a sectional view of the rotary head device of the present invention. A rotating drum 3 is directly attached to the shaft 1, and a core 11 is bonded and fixed to the rotating drum 3 with an adhesive. Then, by moving the screw 10 back and forth, the core 11 is pressed.

The height position of the head chip 50 can be adjusted.

The distance between the cores 11 and 12 that constitute the rotary transformer is usually about 40 μm to 50 μm, whereas the height adjustment distance of the head is 5 μm to 10 μm.
Even if the height of the head is adjusted, sufficient clearance between the cores 11 and 12 is ensured. With such a configuration, the number of parts can be significantly reduced.

In the embodiment described above, the coils 32 and 33 constituting the two heads are connected in series, and the coil serving as the rotary transformer has only one channel (only the coil 13).As a result, the current flowing through the coil 32 is 3
3 will also flow. However, in R-DAT, the two rotating heads 180 degrees apart contact the magnetic tape only 90 degrees each, ensuring that when one is in use the other is not. Therefore, by time-sharing the input and output of the rotary transformer for one channel, signals can be recorded and reproduced in the same way as in the case of two channels. In this way, the diameter of the rotary transformer,
Therefore, the diameter of the rotating drum 3 can be made smaller.

FIG. 8 represents a block diagram of the rotary head device of the present invention. The signal generated in coil 32 (or 33) flows through coil 13. At this time, since the rotary transformer is configured together with the coil 13, a signal flows to the coil 14. This signal is amplified by an amplifier circuit 71 and then output to a switch 72. A pulse generator (PG) 73 is attached to the shaft 1, and the pulse generator 73 generates PG pulses synchronized with the rotational position of the rotating drum 3 (head). The timing signal generation circuit 74 generates a timing signal (head switching pulse) corresponding to the rotational position of the pair of heads using this PG pulse as a reference. The switch 72 is switched by this timing signal. For example, the switch 72 is switched to the contact a side when the head of the coil 32 is in contact with the magnetic tape, and to the contact side when the head of the coil 33 is in contact with the magnetic tape. Therefore, contacts a and b
The outputs of one head and the other head can be taken out from respectively.

By supplying signals from contacts a and b in the same way,
A signal can be supplied to one head and the other head.

11 and 12 show an embodiment in which a groove 81 is formed laterally in the protrusion 31 of the embodiment shown in FIGS. 1 to 3. In this embodiment, the stress caused by the screw 10 is concentrated in the groove 81, so even if the height of the head is adjusted, the core 11 and
This has the advantage that the clearance D of 2 hardly changes and the characteristics as a rotary transformer do not deteriorate.

13 and 14 show a core 92 dedicated to the magnetic head as a bridge core in addition to the core 11 of the rotary transformer.
An embodiment is shown in which the core 11 and the core 92 are coupled by a coupling member 91 made of a non-magnetic material such as metal or ceramic. In this embodiment, the magnetic circuit for the rotary transformer and the magnetic head are separate, so
A suitable core material can be selected for each. Also, mutual interference can be eliminated. Furthermore, in this embodiment, distortion to the core 11.92 due to height adjustment can be minimized.

FIG. 9 shows yet another embodiment. In this embodiment, loops 41A and 42A connect coil 32, loops 41B and 42B connect coil 33, and coil 131
and 132 constitute the coil 13, respectively. The loop 41A of the coil 32 is connected in series with the loop 41B of the coil 33 via the coil 131, and the loop 42A of the coil 32 is connected via the coil 132 to the loop 41B of the coil 33.
The loop 42B is connected in series with the loop 42B. Also in this embodiment, when magnetic flux flows out from one of the loops 41A and 42A (the same applies to 41B and 42B) and flows into the other,
The directions of currents flowing through the coils 131 and 152 are the same. Therefore, signals can be transmitted and received via the rotary transformer.

In the embodiment of FIG. 10, loop 41 of coil 32
and 42 are connected via the coil 133.

Loops 41 and 42 of coil 33 are connected via coil 134. The coil 13 is composed of the coil 133 and the coil 134. In this embodiment, coil 32 and coil 33 are not directly connected in series. However, both coil 133 and coil 134 are substantially 1
It only functions as a rotary transformer for the channels.

The present invention can also be applied to a conventional magnetic head having a structure in which a coil is wound around a core. In this case as well, the number of parts can be reduced compared to the conventional case, the rotary head device can be made more compact, and costs can be reduced.

〔effect〕

As described above, the present invention provides a rotary head device including a first core constituting a rotor, and a first core disposed in the first core so as to constitute a part of a rotary transformer for substantially one channel. coil and connected together to the first coil. A pair of heads separated by 180 degrees from each other, a second core constituting a stator, and a second core configured to constitute a part of a rotary transformer for substantially one channel together with the first coil. Since the second coil is arranged in the second coil, the structure is not only simplified, but also the cost and size can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the rotor of the present invention, Fig. 2 is a perspective view of its coil, Fig. 3 is an assembled perspective view of the head chip and coil, Fig. 4 is a perspective view of the head chip, and Fig. 5. 6 is an assembled perspective view of the head chip and conductive member, FIG. 7 is a sectional view of the rotating head device, FIG. 8 is a block diagram thereof, and FIG. 9 is an assembly of the coil and rotor of another embodiment. FIG. 10 is a perspective view of a coil of another embodiment, FIG. 11 is a perspective view of another embodiment of the rotor, and FIG.
13 is a perspective view of still another embodiment of the rotor, FIG. 14 is a sectional view thereof, FIG. 15 is a sectional view of a conventional rotary head device, and FIG. 16 is a sectional view of the head. FIG. 1...Shaft 2...Flange 3...Rotating drum 4...Screw 5...Washer 6...Head 7...Dime 8...Screw 9...Washer 1o... Screws 11, 12...Core 13 to 16...Coil 17...Fixed drum 18...Relay board 19...Dime board 21...Core 22...Magnetic gap 23...End part 24...Coil 31...Protrusion 32.33...Coil 41.42...Loop 41A, 41B, 42A, 42B...Loop 5o...
・Head chip 51, 52... Core 53... Magnetic gap 54... Member 61... Conductive plate 62... Adhesive 71... Amplifier circuit 72... Switch 73... Pulse generator 74...Timing signal generation circuit 81...Groove 91...Coupling member 92...Core 131 to 134...Coil or above

Claims (1)

[Claims] a first core constituting a rotor; a first coil disposed in the first core so as to constitute a part of a rotary transformer for substantially one channel; A pair of connected heads spaced apart from each other by 180 degrees, a second core constituting a stator, and a rotary transformer configured to substantially constitute a part of a rotary transformer for one channel together with the first coil. A magnetic head device comprising: a second coil disposed in a second core.