JP3481120B2 - Disk centering mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium disk such as an optical disk or a magneto-optical disk mounted on a turntable, which is integrally driven together with the turntable to drive information signals recorded on the disk. reading,
Or disk cell for recording information signals on the disc
Related to the switching mechanism.

[0002]

2. Description of the Related Art In a disk drive device for recording or reproducing an information signal on or from a recording medium disk such as an optical disk or a magneto-optical disk, the disk is recorded on the recording track of the disk. It is necessary to rotationally drive the disc with the optical pickups facing each other. For this reason, the disk drive device has a disk chucking mechanism including a turntable on which the disk is placed at a predetermined position and is rotationally driven together with the disk by the rotational drive mechanism. As a conventional example of the disk chucking mechanism, there is one described in JP-A-3-157859.

The disk drive disclosed in the above publication eliminates the movement of the disk in the direction of the rotation center axis in the disk chucking state and eliminates the need for a chucking plate for pressing the disk from the opposite side of the turntable toward the turntable. The purpose is to reduce the size and thickness of the device. Therefore, the ones described in the above publication are
A turntable on which a disc having a center hole is placed and driven to rotate, a fitting body provided at the center of the turntable and fitted in the center hole of the disc, and a turntable provided in the fitting body and elastic. A plurality of spherical members that are urged to project outward from the fitting body by a member and press and support the disk placed on the turntable toward the turntable side. According to the above-mentioned publication, when the disc is placed on the turntable, the plurality of spherical members that are biased toward the outer side of the fitting body come into contact with the upper edge of the central hole of the disc. Therefore, the disc is pressed and supported on the turntable side, and mounted and held on the turntable.

According to the conventional disk chucking mechanism as in the invention described in the above publication, there is no movement of the disk in the rotation center axis direction in the disk chucking state, and
A chucking plate for pressing the disc from the opposite side of the turntable toward the turntable is unnecessary, and the disc drive device can be made smaller and thinner.

[0005]

However, according to the conventional disk chucking mechanism, a plurality of spherical members which are urged outwardly of the fitting body are brought into contact with the upper edge of the central hole of the disk. The disk mounted on the turntable is pressed to the turntable side to be mounted on the turntable, and the centering of the disk is performed at a position where the projecting biasing forces of the plurality of spherical members are balanced. Therefore, if the projecting biasing forces of the plurality of spherical members are not equal, there is a problem that the centering varies. In particular, when the plurality of spherical members are independently biased, the biasing force of each spherical member tends to vary, and the disc centering deviation tends to increase.

In the disk chucking mechanism described in the above publication, a ring made of an elastic material such as rubber is used as the urging means, and a plurality of spherical members are urged by one elastic body ring. There is an advantage that the protruding biasing force of the member is relatively averaged. However, since the centering of the disc is done by a plurality of spherical members that are biased toward the outside of the fitting body and there is no fixed positioning reference point, the disc is parallel to its plane in the chucking state. There is a difficulty in moving and rattling in a wide area. Further, there is a possibility that the centering may shift due to variations in the composition and size of the elastic ring, uneven external force when the disc is mounted, and various other conditions, and there is room for improvement.

The present invention has been made in order to solve the above-mentioned problems of the prior art. In the disk chucking state, the disk is hard to move in a plane parallel to the plane of the disk, and there is no rattling. It is an object of the present invention to provide a disc centering mechanism in which centering deviation is unlikely to occur.

[0008]

In order to achieve the above object, according to the present invention, as described in claim 1, a disc having a central hole is placed and is rotated by a rotary drive mechanism. Disc center with table
A ring mechanism, the turntable, and the body of the central hole is fitted, a first guide portion formed in the body portion integrally protrude from the outer peripheral surface of the body portion in a radial direction, this Second and third guide portions provided so as to be able to advance and retreat in the radial direction at two locations separated by 120 ° from the center of the body portion with respect to the first guide portion, and the second and third guide portions. It is characterized in that it is provided with an auxiliary guide portion which is provided at an intermediate position with respect to the first guide portion and has a smaller amount of protrusion from the body portion than the first guide portion.

As described in the second aspect of the present invention, it is preferable that the auxiliary guide portions are provided at positions symmetrical with respect to the center of the body portion with respect to the second and third guide portions. It is preferable that the first, second, and third guide portions and the auxiliary guide portion are in point contact with the central hole of the disk, as in the third aspect of the invention.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a disk centering mechanism according to the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, the motor 4 which is the main component of the disk rotation drive mechanism is fixed to one surface side (the lower surface side in FIG. 2) of the substrate 11, and the rotation output shaft 18 of the motor 4 is the other surface side of the substrate 11. Protruding vertically from. The disk chucking mechanism 1 is attached to the rotation output shaft 18 of the motor 4.
Is assembled. Disc chucking mechanism 1
Is mainly composed of the turntable 3. The turntable 3 is made of, for example, resin integrally molded,
The turntable 3 is rotationally driven integrally with the rotation output shaft 18 by press-fitting the rotation output shaft 18 of the motor 4 into the central hole of the integrally formed boss 13.

On the upper surface side of the turntable 3, a short cylindrical body 12 is integrally formed along a concentric circle centering on the rotation center of the turntable 3. This body 12
The outer peripheral surface of about half of the upper side of the is a conical surface 14. A center hole of a disc serving as a recording medium fits in the body portion 12, and the conical surface 14 functions as a guide for guiding the center hole of the disc to the body portion 12 during disk chucking. The turntable 3 has a flange-shaped portion continuing from the lower end of the body portion 12, and the upper surface of this flange-shaped portion serves as a disc receiving surface 15, which serves as the axial position (height position) of the chucked disc. ) Is decided.

The illustrated embodiment is a chucking mechanism for a disk having a hub made of a magnetic material such as an MO (magneto-optical) disk, wherein the body 12 has a center of rotation of the turntable 3 as its center. The groove 16 is formed along the concentric circle. The groove 16 is open on the upper surface side, and the ring-shaped chucking magnet 10 is provided in the groove 16.
Is embedded. In FIG. 6, reference numeral 19 indicates an MO disk, and the MO disk 19 has a step portion 22 projecting downward from the disk body at the center, and the step portion 22 and the disk body are intermediate in the thickness direction. An outer peripheral edge portion of a disk-shaped center hub 21 made of a magnetic material such as an iron plate is sandwiched between the portions. The upper surface of the disk 19 main body and the upper surface of the center hub 21 are substantially flush with each other. The magnet 10 attracts the center hub to chuck the disc to the disc chucking mechanism 1. However, in the chucking state, there is a slight gap between the magnet 10 and the center hub, and the lower surface of the stepped portion 22 of the disk 19 contacts the disk receiving surface 15 to determine the axial position of the disk. It has become.

As shown in FIGS. 1 to 4, the body 12 of the turntable 3 has a first guide portion 7 formed integrally with the body 12 so as to project radially from the outer peripheral surface thereof. . The first guide portion 7 draws a gentle arc when viewed from the axial direction of the body portion 12 and projects radially outward from the outer peripheral surface of the body portion 12. In the body portion 12, the second guide portion 5 and the third guide portion 6 are respectively movable in the radial direction at two positions separated from the center of the body portion 12 by 120 ° with respect to the first guide portion 7. It is provided. Although not specifically shown in FIGS. 1 to 4, the second and third guide portions 5 and 6 are formed from the outer peripheral surface of the body portion 12 by a leaf spring, a coil spring, rubber, or another appropriate elastic body. The urging force is regulated so that the urging force urges the diametrically outward direction and the diametrically outward direction of the body portion 12 urges the diametrically outward direction by an appropriate amount. The outer surfaces of the second and third guide portions 5 and 6 are the same as those of the first
Like the guide portion 7 of the above, it is formed in an arc shape when viewed from the axial direction of the body portion 12.

The body portion 12 has an intermediate position between the first guide portion 7 and the second guide portion 5 and the first guide portion 7.
Between the first guide portion 7 and the third guide portion 6, that is, a position separated by 60 degrees from the first guide portion 7 to the second guide portion 5, and the first guide portion 7 to the third guide portion 6. Auxiliary guide portions 8 and 9 are provided at positions separated by 60 degrees toward each other so as to project radially outward from the outer peripheral surface of the body portion 12. The auxiliary guide portions 8 and 9 are the first guide portion 7
Similarly, when viewed from the axial direction of the body portion 12, a gentle arc is drawn to project radially outward from the outer peripheral surface of the body portion 12.
However, the amount of protrusion of the auxiliary guide portions 8 and 9 from the body portion 12 is smaller than the amount of protrusion of the first guide portion 7 from the body portion 12. The relationship between these protrusion amounts is shown in FIGS.

2, 3 and 4, when the radius of the center hole 20 of the disk 19 as a recording medium is R, the distance from the rotation center of the turntable to the maximum protruding position of the first guide portion 7 is also set. When the disc 19 is chucked by the disc chucking mechanism according to this embodiment, the disc 19 comes into point contact with the edge of the center hole 20 of the disc at the point A, which is the maximum protruding position. .
When the protrusion amount of the first guide portion 7 from the outer peripheral surface of the body portion 12 at the maximum protrusion position is a and the protrusion amounts of the maximum protrusion positions of the auxiliary guide portions 8 and 9 are respectively c, c is greater than a. Is also getting smaller. Therefore, the distance from the rotation center of the turntable to the maximum protruding position of the auxiliary guide portions 8 and 9 is R
-(A-c). Here, c is set to 1/2 of a.

As shown in FIG. 6, the turntable 3 of the disk chucking mechanism constructed as described above has a center hole 20 and a center hub 21 made of a magnetic material.
When the disc 19 having the disc is chucked, the disc 1 is attached to the disc receiving surface 15 by the magnetic attraction force between the chucking magnet 10 and the center hub 21 as described above.
The lower surface of the step portion 22 of 9 contacts and the disk 19 is positioned in the axial direction. Also, during the chucking operation,
The edge of the center hole 20 of the disk is guided by the first guide portion 7, and the edge of the center hole 20 of the disk hits the second and third guide portions 5 and 6, and these second and third guide portions are provided. A predetermined chucking position is reached while retracting 5 and 6 against the biasing force. In the chucking state, the edge of the center hole 20 of the disk makes point contact with the maximum protruding positions D and E of the second and third guide portions 5 and 6, and the biasing force of the second and third guide portions 5 and 6 is exerted. The disk is urged toward the outer side in the radial direction at the positions of the respective guide portions 5 and 6. The edge of the center hole 20 of the disk comes into contact with the point A of the first guide portion 7 on the opposite side to the resultant direction of the urging force, and the urging force of the second and third guide portions 5 and 6 is applied. The movement of the disc in the radial direction is restricted, and the above A, D,
The disk 19 is centered by the three points E. In the state where the centering is performed, the above (a-c) is provided between the edge of the disk center hole 20 and the auxiliary guides 8 and 9.
There is a minute gap.

As described above, one of the three points for centering the disk is integrally provided on the body portion 12 of the turntable 3 and is fixed in the relative relationship with the body portion 12 of the first guide. Since part 7 is provided, one of the three points for centering the disc is fixedly determined, and compared with the conventional one in which all the points for centering the disc can be moved forward and backward. As a result, the centering standard can be determined reliably and clearly, which enables highly accurate centering.

When the position of the disk center hole 20 deviates from the position of the body 12 of the turntable 3 during the chucking operation of the disk, the first guide portion 7, the second,
In addition to the third guide portions 5 and 6, the auxiliary guide portions 8 and 9 also exert the guide function to assist the centering of the disc. Furthermore, even when the disc is chucked,
For some reason, the disc is the body 12 of the turntable 3.
There is a possibility that a position shift may occur with respect to. For example, when the disc is driven to rotate, inertial force, air resistance, etc. of the disc may cause the disc to be displaced relative to the body portion 12. This discrepancy is caused by the fact that the first guide portion 7 is fixed, while the second and third guide portions 5 and 6 can move forward and backward in the radial direction of the body portion 12, so that the disc has a central hole. The contact point A between the edge of 20 and the first guide portion 7 is centered, and it moves relative to the body portion 12 while drawing an arc as shown by arrows 30 and 40 in FIG. In FIG. 4, the gap between the edge of the center hole 20 of the disc and the auxiliary guide portions 8 and 9 is emphasized and drawn large, but this gap is actually small, and as described above, the disc is circular about point A. When the relative movement of the disk is attempted, the edge of the center hole 20 of the disk immediately contacts the maximum protruding position B of the auxiliary guide portion 8 or the maximum protruding position C of the other auxiliary guide portion 9, and the relative movement of the disk is restricted. To be done.

As described above, the second guide portion 5 and the third guide portion 6 which can advance and retreat in the radial direction are provided on the first guide portion 7 at two positions separated by 120 ° from the center of the body portion 12,
At the intermediate position between the second and third guide parts 5, 6 and the first guide part 7, and at the second and third guide parts 5, 6
On the other hand, since the auxiliary guide portions 8 and 9 each having a smaller protrusion amount from the body portion 12 than the first guide portion 7 are provided at positions symmetrical with respect to the center of the body portion 12, while the disk is rotationally driven, Even if the disk moves relative to the body in the direction parallel to the plane due to the factor, the relative movement of the disk is immediately restricted by the auxiliary guide portions 8 and 9, and the movement of the disk is restricted to a small range. Further, even if the displacement of the disc occurs in this way, the first guide portion 7, the second and third guide portions 5 and 6 are centered at a predetermined position, and the displacement is eliminated. Moreover, since the maximum protrusion amount of the auxiliary guide portions 8 and 9 is smaller than that of the first guide portion 7, it is possible to mount a disc whose inner diameter of the center hole is smaller than the maximum protrusion amount of the first guide portion 7. Even if there is, the centering performance as described above can be similarly secured. In addition, for convenience of explanation, the guide portion 5 is set to the second position.
Although the guide part and the guide part 6 are referred to as the third guide part, the guide part 6 may be referred to as the second guide part and the guide part 5 may be referred to as the third guide part.

It has been described above that the disk has a hub made of a magnetic material, and the disk is pressed against the disk receiving surface 15 by the attraction force of the hub by the chucking magnet to perform axial positioning. However, since compact discs and the like do not have a magnetic body and cannot perform disc chucking using a chucking magnet, it is necessary to press the disc against the disc receiving surface 15 by means other than magnetic force. According to the embodiment described so far, by devising the shapes of the first guide portion 7, the second and third guide portions 5, 6, it is possible to generate a force for pressing the disc against the disc receiving surface 15. You can That is, the outer surface of the first guide portion 7, the second and third guide portions 5, 6 is spherical or a shape similar thereto,
The upper edge of the central hole of the disk is made to contact the jaws of the first guide portion 7, the second and third guide portions 5 and 6. The upper edge of the center hole of the disk abuts the jaws of the second and third guide portions 5 and 6, and the second and third guide portions 5 and 6 are attached to the outer side of the body portion 12 in the radial direction. By being urged, a force for pressing the disc against the disc receiving surface 15 is generated. If the upper edge of the center hole of the disc is brought into contact with the jaw of the first guide portion 7 by this urging force, the force for pushing the disc against the disc receiving surface 15 is also generated.

The first guide portion 7, the second and third guide portions 5, 6 for pressing the disc against the disc receiving surface 15 by the first guide portion 7, the second and third guide portions 5, 6 are provided. The shape of is not limited to the spherical shape described above, and may be any shape as long as a predetermined function can be obtained. For example, it may be a toric surface, that is, an annular surface, or a conical surface.

The shapes of the second and third guide portions 5 and 6 are not particularly limited, but as an example, as shown in FIG. 5, one leaf spring 40 is used to make the second and third guide portions. Three
The guide portions 5 and 6 may be configured. In FIG. 5, 1
Although the leaf spring 40 of a sheet extends linearly in a natural state, an attachment portion 41 formed by bending the center portion in the length direction is fixed to the bottom surface side of the turntable 3, and both leaf springs 40 are attached. The arm portion is bent along the arc of the turntable 3 in an arc shape, and both ends of the leaf spring 40 are applied to the stoppers 32, 32 integrally formed on the turntable 3, whereby the leaf spring 40 is biased. It is held in a state.
Second and third guide portions 5 and 6 are formed near both ends of the leaf spring 40. The guide portions 5 and 6 are formed toward the outside of the turntable 3 by punching out portions of the leaf spring 40 near both ends. The guide parts 5 and 6 penetrate through the window holes 31 and 31 formed by penetrating the turntable 3 in the vertical direction, and project outward in the radial direction from the outer peripheral surface of the body of the turntable 3 as described above.

If the second and third guide portions 5 and 6 are constructed as shown in FIG. 5, one leaf spring 40 can form the second and third guide portions 5 and 6. It is possible to simplify the configuration and reduce the number of parts. Moreover, since the second and third guide portions 5 and 6 are composed of one leaf spring 40, the urging forces of the second and third guide portions 5 and 6 can be made uniform, and the disc chucking can be performed. The time centering can be performed accurately.

FIG. 6 shows a specific example of a structure for mounting the chucking magnet 10 and another example of a metal plate integrally having the second and third guide portions 5 and 6. In FIG. 6, a metal plate 5 is provided on the bottom of the groove 16 of the turntable 3.
1, the magnet yoke 60 made of a magnetic material such as iron is overlaid on the metal plate 51, and the chucking magnet 10 is overlaid on the magnet yoke 60. The magnet yoke 60 has an appropriate number of locking portions 62 formed by bending downward and an appropriate number of magnet biasing portions 61 formed by bending upward. The locking portion 62 penetrates through the metal plate 51 and the hole 34 formed in the turntable 3 in the central axis direction and is locked to the turntable 3, so that the locking portion 62 itself and the metal plate 51 are turned. It is integrally attached to the table 3. The magnet urging portion 61 is bent along a conical surface 10a formed at an upper portion on the inner peripheral side of the chucking magnet 10 and is pressed against the conical surface 10a by its elastic force, so that the chucking magnet 10 is turned. It is integrally attached to the table 3. The second and third guide portions 5 and 6 stand up from the outer peripheral edge of the metal plate 51 between the outer peripheral wall of the groove 16 of the turntable 3 and the outer peripheral surface of the chucking magnet 10, respectively. Is formed at the tip of an elastic portion 52 bent along the conical surface 14.

The disk chucking mechanism according to the present invention can be applied to a drive device such as a compact disk or a digital video disk in which the hub portion of the disk is made of a non-magnetic material, or the hub portion of the disk. It can also be applied to a drive device such as a magneto-optical (MO) disk made of a magnetic material.

[0026]

According to the present invention, the turntable has a body portion into which the center hole of the disk fits, and a first body formed integrally with the body portion so as to radially project from the outer peripheral surface of the body portion. Since it has the guide portion and the second and third guide portions provided so as to be able to advance and retreat in the radial direction at two locations separated from the center of the body portion by 120 ° with respect to the first guide portion, The first guide portion, which is one of the three points for centering the disc, is integrally provided on the body of the turntable and is immovable in the relative relationship with the body, so as to center the disc. Since one of the three points is fixedly determined, the standard of centering is surely determined as compared with the conventional one in which all the points for centering the disk can be moved forward and backward. Highly accurate centering is possible It is.

Further, since the auxiliary guide portions are provided at intermediate positions between the second and third guide portions and the first guide portion, the disc center hole position is changed during the chucking operation of the disc. When the body of the turntable is displaced from the position, the auxiliary guide portion assists the centering of the disc. Further, this auxiliary guide portion has a smaller amount of protrusion from the body portion than the first guide portion, and when the disc is chucked, the disc is misaligned with respect to the body of the turntable for some reason. When this occurs, the edge of the center hole of the disk immediately contacts the auxiliary guide portion, so that the relative movement of the disk is restricted and the positional deviation of the disk is limited to a slight range.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a disk centering mechanism according to the present invention.

FIG. 2 is a partially sectional front view of the above embodiment.

FIG. 3 is a plan view showing a relationship between a first guide portion and an auxiliary guide portion in the above embodiment.

FIG. 4 is a plan view showing a relationship between a first guide portion, a second guide portion, a third guide portion, and an auxiliary guide portion in the above embodiment.

FIG. 5 is a bottom view showing an example of second and third guide portions applicable to the present invention.

FIG. 6 is a front sectional view showing an example of a chucking magnet attachment mechanism applicable to the present invention and a state where a disk is chucked.

[Explanation of symbols]

1 Disc chucking mechanism 3 turntable 5 Second guide section 6 Third guide part 7 First guide part 8 Auxiliary guide section 9 Auxiliary guide section 12 torso 19 discs 20 disc center hole

Continuation of front page (56) Reference JP-A-7-65472 (JP, A) JP-A-8-63847 (JP, A) JP-A-8-83466 (JP, A) JP-A-11-273203 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G11B 17/022-17/035

Claims (3)

(57) [Claims] 1. A disc centering mechanism including a turntable on which a disc having a center hole is placed and which is rotationally driven by a rotary drive mechanism, wherein the turntable has a body portion into which the center hole is fitted. A first member formed integrally with the body by projecting radially from the outer peripheral surface of the body.
Guide portion, second and third guide portions provided so as to be able to advance and retreat in the radial direction at two locations separated by 120 ° from the center of the body portion with respect to the first guide portion, and the second guide portion.
And an auxiliary guide portion that is provided at an intermediate position between the third guide portion and the first guide portion and has a smaller amount of protrusion from the body portion than the first guide portion. And a disk centering mechanism. 2. The disk centering mechanism according to claim 1, wherein the auxiliary guide portions are respectively provided at positions symmetrical with respect to the center of the body portion with respect to the second and third guide portions. . 3. The disk centering mechanism according to claim 1, wherein the first, second and third guide portions and the auxiliary guide portion are in point contact with the center hole of the disk.