JP2968129B2 - Noise-saving rotary head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device in which a rotary drum is driven to rotate by a motor, and more particularly to a motor for driving a rotary drum, which can prevent noise from being applied to other electric components. A rotary head device with reduced noise.

[0002]

2. Description of the Related Art FIG. 10 is a partial plan view showing a tape running section of a tape player using a rotary head device such as a VTR. The rotary head device 1 is provided with a rotary drum 2 that is driven to rotate by a motor, and the rotary drum 2 has magnetic heads H1, H2, H3, and H4 mounted thereon. The magnetic tape T pulled out from the tape reel on the supply side is guided by the guide posts 3a and 3b and the loading post 3c, wound around the rotary head device 1 at a predetermined angle, and further guided by the loading post 3d and the guide posts 3e and 3f. Then, the capstan 4 is pinched between the capstan 4 and the pinch roller 5, and the capstan 4 is caused to run in a direction indicated by an arrow in FIG.

The fixed head includes a full width erasing head Ha, a voice erasing head Hb, and a voice / control head Hc. With these fixed heads, the voice / control head H
c. When noise is given to the head Hc, it is superimposed on the reproduced sound as audio noise.

[0004]

As a noise source affecting the voice / control head Hc, there are a power supply, a switch circuit, and the like.
Alternatively, by arranging the head away from the audio / control head Hc, the problem of giving noise can be reduced.

However, the voice / control head Hc
There is a motor for driving a rotary drum as a device that gives noise to the motor. In this type of motor, a stator core having a coil is provided on a stator side, and a magnet is provided on a rotor side. Leakage magnetic flux of a magnetic field generated by the stator core affects the sound / control head Hc as noise. Will be.

Particularly, in recent models, a motor for rotating and driving the rotary drum 2 is disposed above the rotary head device 1 in many cases. In this type of device, since the motor and the audio / control head Hc are not shielded by the chassis or the like and are arranged in the same space area on the chassis, the influence of noise given to the audio / control head Hc cannot be ignored. It has become something.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and eliminates the influence of noise given to a noise-dissipating electric component such as a voice / control head from a motor for rotating a rotary drum. It is another object of the present invention to provide a noise-saving rotary head device capable of reducing noise.

[0008]

According to the present invention, there is provided a fixed drum, a rotating drum coaxial with the fixed drum and provided with a magnetic head, and a drive motor for rotating the rotating drum. Rotating head device,
As a first means, a drive motor is provided with a plurality of stator cores arranged in a circumferential direction and an auxiliary slot having a size larger in a circumferential direction than the stator core, and a line connecting an electric member which dislikes noise and the center of the motor. Alternatively, the auxiliary slot is located or close to the extension of this line .

As a second means, the drive motor includes:
Opposite to electrical parts that dislike noise around the center of the motor
It is preferable that a PG detector is provided at the side position.
New

[0010] As yet a third means, the stator core of the drive motor in the stator part provided, small piece-like metal shield is located on the line connecting the centers of the electrical components and motor dislike noise is located Are preferred.

[0011]

In the first means, the amount of magnetic flux leaking between a plurality of stator cores provided in the drive motor is greater than the amount of magnetic flux leaking between the stator core and the auxiliary slot having a larger dimension. By directing the auxiliary slot or the diagonal position of the auxiliary slot in the direction in which the noise-dissipating electrical components such as a voice head are present, for example, the leakage to the noise-dissipating electrical components is prevented. The effect of magnetic flux can be reduced.

In the second means, since the PG detecting section provided on the drive motor and detecting the rotational phase of the rotor is disposed on the side opposite to the part which dislikes noise such as an audio head, the PG detecting section is provided. The leakage magnetic flux from the detection unit is less likely to reach the electric parts that dislike noise, and the noise given to the electric parts that dislike noise can be reduced.

In the third means, since the small metal shield is arranged on the substrate on which the stator core of the drive motor is provided and in the direction in which the electric parts which dislike noise are arranged, This prevents the leakage magnetic flux from reaching the outside due to the magnetic attraction of the small metal shield, thereby reducing the influence of the leakage magnetic flux on electrical components that dislike noise, such as a voice head.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an exploded perspective view of a rotary head device as one embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the rotary head device (sectional view taken along line II-II in FIG. 1), and FIG. FIG. 4 is a partially exploded perspective view showing a stator portion of the motor, and FIG. 4 is a perspective plan view of the stator portion. FIG.
2, reference numeral 11 denotes a fixed drum. A fixed shaft 12 is fixed to the fixed drum 11 by means such as shrink fitting. A rotating drum 15 is rotatably supported on the outer periphery of the fixed shaft 12 via a pair of ball bearings 13 and 14. A plurality of head bases 16 are fixed to the outer peripheral portion of the bottom surface of the rotating drum 15, and a magnetic head H for recording / reproducing video signals is fixed to each head base 16.

At the upper end of the fixed shaft 12, a drive motor M for rotating the rotary drum 15 is provided. The rotor R of the motor M is fixed on the upper surface of the rotating drum 15. The stator S is fixed at the upper end of the fixed shaft 12 via a fixed bush 17. Rotor R
Then, the rotor yoke 2 made of sheet metal formed by drawing into a concave shape
1 has a rotor magnet 22 fixed thereto. As shown in FIG. 2, the rotor magnet 22 has a ring shape having an L-shaped cross section, and has an inner peripheral surface having a drive magnet in which N magnetic poles and S magnetic poles are alternately magnetized in the circumferential direction. Magnetic surface 22
a. The bottom surface of the rotor magnet 22
The magnetic pole is a PG magnetized portion 22b magnetized at one or two locations on the circumference. This PG magnetization is for detecting the rotation phase of the rotor R.

On the bottom surface 21a of the rotor yoke 21,
An insertion hole 21b through which the fixed shaft 12 is inserted upward is formed, and a positioning groove 21c is formed at one location on the outer periphery thereof. A positioning projection 15b is formed on the rotor installation surface 15a on the upper surface of the rotating drum 15, and the positioning projection 15b and the positioning groove 21c are fitted to each other, so that the phase of the rotating drum 15 and the rotor R is adjusted. Are aligned. With this phase adjustment,
Mounting screws 23, 23 (see FIG. 2) are inserted into mounting holes 21d, 21d formed in the rotor yoke 21, and female screw holes 15c, 1 in the rotor installation surface 15a of the rotating drum 15.
5c, and the rotor R and the rotating drum 15 are fixed to each other.

The stator S is provided with a stator substrate 31. The stator substrate 31 is formed of resin, ceramic, or the like, and its upper surface is a mounting surface 31a of an electronic component on which a conductive pattern is formed. As shown in FIG. 2, the fixed bush 17 is fixed to the upper end of the fixed shaft 12 by a headless screw 18, and a stator substrate 31 is fixed to the fixed bush 17 by mounting screws 32, 32. I have.

On the lower surface of the stator substrate 31, a ring-shaped magnetic member 33, a part of which is shown in FIG.
It is fixed by means such as adhesion via (see FIG. 2). As shown in FIG. 3, on the outer periphery of the magnetic member 33,
A plurality of stator cores 35 project radially, and a stator coil C is wound around each of the stator cores 35. Further, auxiliary slots 36 protrude from the same magnetic member 33 at predetermined angles. This auxiliary slot 36
Is such that the circumferential dimension α is longer than the circumferential dimension β of the stator core 35. The auxiliary slot 36 is for preventing a cogging operation when the rotor R rotates. Some of the auxiliary slots 36 are not wound with coils, but in the embodiment shown in FIG.
A stator coil C is wound around the auxiliary slot 36 so as to function also as a stator core.

On the lower surface of the stator substrate 31, a P-type magnet facing the PG magnetized portion 22b of the rotor magnet 22 is provided.
The G detection core 37 is fixed, and the PG detection coil Ca is wound around the PG detection core 37. Although not shown, a Hall element for controlling the energization of the stator coil C is provided on the lower surface of the stator substrate 31.

As shown in FIG. 1, the mounting surface 31a of the stator substrate 31 has an IC as an electronic element for generating noise.
41 are mounted. This IC 41 is mounted on the fixed shaft 12.
It is provided on the left side of the figure. A shield piece 42 is provided on the mounting surface 31a. This shield piece 4
Reference numeral 2 denotes a small metal plate or a small metal foil, which is bonded and fixed to the surface of the mounting surface 31a via an insulating layer such as a resist. In addition, this shield piece 42
It may be formed of a conductive film (print pattern) on the mounting surface 31a.

A connector 43 is provided on the upper surface of the stator substrate 31.
Has been implemented. This connector 43 is mounted on the mounting surface 31a.
Are electrically connected to the stator coil C, the PG detection coil Ca, and the like via the conductive pattern formed in the first coil. In the embodiment of FIG. 1, the connector 43 is provided on the left side 31c of the stator substrate 31 in the figure and on the rear side 31b of the substrate. In this type of rotary head device, the fixed shaft 12
With the center line O of the tilted by θ with respect to the vertical line,
It is fixed on the chassis of the tape player. Therefore, the stator substrate 31 is also inclined by θ with respect to the horizontal line L parallel to the chassis. The connector 43 is provided on the left edge portion 31c, the position of which is lowered by the inclination of the stator substrate 31. Since the connector 43 is mounted on the side where the position of the stator substrate 31 is lowered, the height dimension from the chassis to the upper end of the connector 43 is limited, so that the connector 43 does not hinder the thinning of the entire rotary head device. It has become.

Next, the arrangement angle and arrangement position of each member arranged on the stator S will be described with reference to FIG. FIG. 4 shows the stator S shown in FIG.
FIG. 1 is a perspective plan view showing a perspective view of FIG. When the rotary head device of the above embodiment is mounted on a tape player as shown in FIG. 10, the direction in which the audio / control head Hc is located is indicated by an arrow in FIG. The virtual line 50 provided with the arrow is a line connecting the audio / control head Hc and the rotation center O (the center of the fixed shaft 12) of the rotary head device.

In the above embodiment, as shown in FIG. 4, auxiliary slots 36 are provided at an angle of 120 degrees, and three stator cores 3 are provided between the auxiliary slots 36 and 36.
5 are provided at equal angular intervals. In this embodiment, substantially the center of one of the auxiliary slots 36 (shown by (a)) in the circumferential direction is on the virtual line 50 to the left of the rotation center O, that is, / Located on an extension of the line connecting the control heads Hc. The PG detection core 37 is also provided at a position near the auxiliary slot 36 shown in FIG. Furthermore, the shield piece 42
It is located on a line connecting the rotation center O and the audio / control head Hc. Further, the IC 41 is disposed on the side opposite to the side where the audio / control head Hc is provided with the center O interposed therebetween.

By arranging the members at the angles and positions shown in FIG. 4, noise applied to the voice / control head Hc located in the direction of the arrow in FIG. 4 can be eliminated or minimized. First, by setting the arrangement angles of the stator core 35 and the auxiliary slot 36 provided on the stator S as shown in FIG. 4, the leakage magnetic field in the direction of the voice / control head Hc can be reduced, and the audio noise can be reduced. This will be described with reference to FIGS.

FIG. 5 is a perspective plan view showing a stator S having the same stator core 35 and auxiliary slot 36 as shown in FIGS. In FIG. 5, the stator coil C is wound around the auxiliary slots 36 provided at an angle of 120 degrees to function also as a stator core. Further, the center position in the circumferential direction of the stator core 35 shown in (b) is set at 0 degree, and each stator core 35 and the auxiliary slot 36 are compared with the angle diagram starting from 0 degree. Is shown.

FIG. 7 shows the same angles as in the angle diagram shown in FIG. FIG. 7 shows a relative state between the stator R and the audio / control head in a state where the stator R and the auxiliary slot 36 shown in FIG. The change in the intensity of the audio noise superimposed on the audio / control head when the facing angle position is changed starting from the position at 0 degrees is indicated by (dBm). As shown in FIG. 7, the intensity of the audio noise due to the influence of the leakage magnetic field from the stator decreases at the positions indicated by (a) to (f) and increases at other positions. Comparing the positions shown in (a) to (f) with the positions of the respective parts of the stator S shown in FIG. 5, (a) is almost the angular position of the auxiliary slot 36 shown in (c), and (b) Is its diagonal position. Similarly, (c) and (e) are the angular positions of the auxiliary slot 36 substantially indicated by (d) and (e), respectively.
(D) and (f) are their diagonal positions.

That is, the intensity of the leakage magnetic field decreases around the position where each auxiliary slot 36 is provided and around the diagonal position thereof, and audio noise caused by the leakage magnetic field is reduced. I understand. The reason why the leakage magnetic field is reduced is that, as shown in FIG.
Between the stator core 35 and the stator core 35, and between the stator core 35 and the auxiliary slot 36, the magnetic fluxes Φ1 and Φ2 pass through the opposed rotor magnet 22 and the rotor yoke 21 and pass to the stator core 35 or the auxiliary slot 36. Since the auxiliary slot 36 has a circumferential length greater than that of the stator core 35, the magnetic flux of the auxiliary slot 36 becomes stronger than the magnetic flux of the stator core 35, and thus the magnetic flux Φ1 passing between the stator cores 35 and 35.
It is predicted that the leakage magnetic flux Φ4 of the magnetic flux Φ2 passing through the auxiliary slot 36 is smaller than the leakage magnetic flux Φ3 from This change in the leakage magnetic flux also appears on the diagonal side in a similar manner.

However, in FIG. 7, the angular position where the audio noise is reduced most is necessarily the auxiliary slot 36.
May not be coincident with the circumferential center point, and a shift may occur. This is because since the rotor R rotates at a predetermined speed, the position where the leakage magnetic field decreases may be shifted in the circumferential direction due to the transient phenomenon. The amount of shift in the circumferential direction of the position where the audio noise is reduced is also affected by the rotation speed of the rotor R. Further, when the rotation speed is high due to a transient phenomenon, the leakage magnetic flux becomes large, and when the rotation speed is low, the leakage magnetic flux becomes small. Therefore, if electric parts which dislike noise are arranged at or near the position where the auxiliary slot 36 is provided and on the extension of these diagonal positions, the influence of noise given to these electric parts from the motor M is minimized. Can be limited.

FIG. 6 is a perspective plan view showing a stator Sa of a type different from those shown in FIGS. 3, 4, and 5. FIG. In this stator Sa, the auxiliary slot 3 where no coil is wound is provided.
6a are provided at three positions at an arrangement angle of 120 degrees. In FIG. 6, the arrangement angle of the auxiliary slot 36a is shown in FIG.
The same direction as the arrangement angle of the auxiliary slot 36 shown in FIG. Four stator cores 35a are arranged at equal angles between the auxiliary slots 36a and 36a. A stator coil is wound around each of the stator cores 35a.

FIG. 8 shows a state in which the stator coil wound around the stator core 35a of the stator Sa shown in FIG. 6 is energized to rotate the rotor R, and the angle of opposition to the audio / control head Hc is set to 0 degree as a starting point. The change in the intensity of the audio noise when it is changed to is shown in an angle diagram. As shown in FIG. 8, also in this stator Sa, when the angular position sound / control head Hc shown in (a) to (f) faces, the intensity of the audio noise due to the leakage magnetic field is greatly reduced. The angles shown in (a) to (f) are different from those of the respective auxiliary slots 36a.
Are almost coincident with the angular position at which is provided and the diagonal position thereof. In the stator Sa shown in FIG.
The positions at which the audio noise is reduced as shown in (a) to (f) do not necessarily coincide with the center position of the auxiliary slot 36a and its diagonal position.
In some cases, the auxiliary slot 36a and its diagonal position may deviate from the position where the leakage magnetic field decreases as shown in FIGS.

When FIG. 7 is compared with FIG. 8, the intensity of audio noise in the audio / control head Hc arranged at the angular positions in FIGS. This is considered to be based on the difference in the arrangement angular density of the stator core between the auxiliary slots. Further, it is considered that this is affected by the difference in the circumferential width (β in FIG. 3) of the stator core. That is, since the width dimension of the stator core shown in FIG. 6 is smaller than the width dimension of the stator core shown in FIG. 5, there is a large difference in the magnetic flux collecting force between the stator core 35a and the auxiliary slot 36a in FIG. It is expected that the drop in the magnetic field will be significant.

In the embodiment shown in FIG.
Among them, the one shown in (a) is on an extension of the line connecting the center O of the motor M and the voice / control head Hc. That is, the diagonal direction of the auxiliary slot 36 shown in (a) is directed to the audio / control head Hc. Therefore, the angle direction in which the leakage magnetic field from the stator S is reduced is directed to the audio / control head Hc, and audio noise in the audio / control head Hc is eliminated or reduced.

Next, FIG. 9 shows the intensity change of the audio noise in the voice / control head Hc when the IC 41 is arranged on the stator substrate 31 when the rotor S shown in FIG. 5 is used. This is shown in the same manner as in FIG. As shown in FIG. 9, when the part on which the IC 41 is mounted is directed to the audio / control head Hc, the intensity of the audio noise increases. This is because the electromagnetic wave generated from the IC 41 is transmitted to the voice / control head Hc together with the leakage magnetic field from the stator S,
This is because audio noise is superimposed on the voice / control head Hc.

In the embodiment shown in FIG. 4, the IC 41 is arranged on the opposite side of the direction in which the voice / control head Hc is provided, with the motor center O interposed therebetween. With this arrangement, I
Audio noise generated in the voice / control Hc by the electromagnetic wave from C41 can be reduced. Further, the leakage magnetic field from the stator S is generated not only from the stator core 35 and the like but also from the PG detection core 37. That is, the PG on the PG magnetized portion 22b of the rotor magnet 22
When the magnetization is opposed to the PG detection core 37, the magnetic flux passes between the PG magnetization part 22b and the PG detection core 37. The leakage magnetic flux at this time affects the sound / control head Hc, Also causes audio noise. In the embodiment of FIG. 4, the PG detection core 37 is
Along with the auxiliary slot 36 shown in (a), the PG detection core 37 is provided substantially on an extension line connecting the motor center O and the audio / control head Hc, and the PG detection core 37 is located away from the audio / control head Hc.
The generation of audio noise due to a magnetic field leaking from the microphone can be reduced.

Further, in the embodiment shown in FIG. 4, the shield piece 42 is provided on the stator substrate 31 in the direction in which the audio / audio head Hc is provided. When the shield piece 42 is provided, the leakage magnetic flux generated from the stator core 35 and the like is collected by the shield piece 42, and the leakage magnetic field is less likely to reach the position of the audio / control head Hc. The generation of noise can be further reduced.

As described above, in this embodiment, as shown in FIG. 4, the auxiliary slot 36 shown in FIG. 4A is provided on an extension of the line connecting the motor center O and the audio / control head Hc. A PG detection core 37 is provided at substantially the same position as this, an IC 41 is provided at a position away from the audio / control head Hc, and a shield piece 42 is provided.
Is provided on the line connecting the motor center O and the voice / control head Hc, so that the motor M can eliminate or greatly reduce audio noise given to the voice / control head Hc.

In the embodiment shown in FIG. 4, the auxiliary slot 36 shown in FIG.
The auxiliary slot 36 is provided at or near a diagonal position in the direction in which the control head Hc is provided, and is provided on or near an imaginary line connecting the motor center O and the audio / control head Hc. , That is, the auxiliary slot 36 is the voice / control head Hc.
May be arranged in the direction of. The same applies to the case where a stator Sa provided with an auxiliary slot 36a having no coil as shown in FIG. 6 is used.

Further, in the above-described embodiment, the voice / control head Hc is shown as an electric component which dislikes noise.
This audio / control head Hc is arranged in the direction indicated by the arrow in FIG.
Although the audio noise of c is reduced, the electrical parts that dislike the noise are not limited to the voice / control head Hc, and other heads and parts that dislike the noise such as the signal transmission path of the head are arranged in the direction of the arrow in FIG. May be.

[0039]

As described above, according to the present invention, it is possible to eliminate or reduce the occurrence of noise in the audio / control head and the like by using the motor for rotatingly driving the rotary drum. become able to.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a rotary head device according to an embodiment of the present invention;

FIG. 2 is a longitudinal sectional view of the rotary head device shown in FIG. 1, taken along the line II-II.

FIG. 3 is a partially exploded perspective view showing a stator portion of the rotary head device shown in FIG. 1;

FIG. 4 is a perspective plan view of a stator portion,

FIG. 5 is an explanatory view showing an arrangement angle of a stator core and an auxiliary slot,

FIG. 6 is an explanatory view showing an arrangement angle of a stator core and an auxiliary slot of a stator having another structure;

FIG. 7 is a diagram showing a change in the intensity of audio noise when the facing angle position between the stator and the audio / control head shown in FIG. 5 is changed;

FIG. 8 is a diagram showing a change in the intensity of audio noise when the facing angle position between the stator and the audio / control head shown in FIG. 6 is changed.

FIG. 9 is a diagram showing a relationship between an angular position facing an audio / control head and a change in audio noise intensity when an IC is mounted on the stator shown in FIG. 5;

FIG. 10 is a plan view showing a part of a tape running path in a rotary head device portion such as a VTR.

[Explanation of symbols]

 Reference Signs List 11 fixed drum 12 fixed shaft 15 rotating drum 16 head base M motor R rotor 21 rotor yoke 22 rotor magnet S stator 31 stator substrate 33 magnetic member 35, 35a stator core 36, 36a auxiliary slot 37 PG detection core 41 IC 42 shield piece Hc voice / Control head

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-55-150125 (JP, A) JP-A-4-133649 (JP, A) JP-A-2-50357 (JP, A) 93486 (JP, U) Japanese Utility Model Showa 60-14674 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02K 29/00 G11B 5/52 101 H02K 21/22

Claims (3)

(57) [Claims] 1. A rotary head device comprising: a fixed drum; a rotary drum rotating coaxially with the fixed drum and provided with a magnetic head; and a drive motor for driving the rotary drum to rotate. The motor is provided with a plurality of stator cores arranged in the circumferential direction and an auxiliary slot having a size larger in the circumferential direction than the stator core,
A noise-saving rotary head device, wherein the auxiliary slot is located or close to a line connecting an electric member that dislikes noise and the center of the motor or an extension of this line. 2. The driving motor has a P at a position opposite to the electric parts which dislike noise, with the center of the motor interposed therebetween.
The noise reduction circuit according to claim 1, further comprising a G detection unit.
Rolling head device. The 3. A stator section stator core is provided of the driving motor, according to claim lump metallic shield located on the line connecting the centers of the electrical components and motor dislike noise is located 1 or 2 The described noise-saving rotary head
apparatus.