JPH10208345A - Disk clamping mechanism for disk recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate deviation between the centers of an equipping hole and a clamper even when the deviation takes place. SOLUTION: A centering mechanism 5 for making the centers of the equipping hole 25 and the clamper 4 coincide with each other is equipped concentrically with the equipping hole 25. This centering mechanism 5 is composed of a groove part 26 formed in a circular-arcuate shape with its cross section of an approximately V-shape in one out of a frame 3 and the clamper 4 and sliding parts 49 more than two in number arranged on the other one out of the frame 3 and the clamper 4 in the circumferential direction at approximately equal intervals and to be brought into contact with a bottom part of the inner surface of the groove part 26 under the state where the centers of the equipping hole 25 and the clamper 4 are matched with each other and also the to be slidable on the inner surface of the groove part 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk clamp mechanism for a disk recording / reproducing apparatus for a CD (compact disk) or the like.

[0002]

2. Description of the Related Art Some CD players are shown in FIGS. In this apparatus, a reproducing section 63 for reproducing the CD 61 is provided below a tray 62 on which the CD 61 is placed.
Is provided at the rear end so as to be vertically swingable by a support shaft 64, and is driven to swing vertically by a cam mechanism 65. A spindle motor 66 is provided at the front of the reproducing unit 63, and the motor 66 is provided with a turntable 67. Turntable 67 is CD6
1 is mounted thereon, and a round shaft-shaped engaging portion 68 is provided upright at a central portion thereof.

[0003] A frame 70 is disposed above the turntable 67, and an equipment hole 71 located above the turntable 67 is formed in the frame 70 so as to extend vertically. Is inserted,
Is held. The clamper 72 is a turntable 6
7, the CD 61 is clamped from above and below, and has a cylindrical holder 73 opening upward, a magnet 74 fitted in the holder 73, an upper end opening of the holder 73, and an equipment hole 71. It is composed of a larger diameter yoke 75 and the like.

The holder 73 has an inverted L projecting upward.
Three claw portions 77 are formed at equal intervals in the circumferential direction, and the claw portions 7 are formed through elastic deformation of the claw portions 77 inward in the radial direction.
The holder 73, the magnet 74, and the yoke 75 are integrated by inserting the 7 into the hole 78 of the yoke 75 and engaging with the upper surface of the yoke 75. The bottom wall of the holder 73 has a diameter larger than that of the equipment hole 71, and a cylindrical engaged portion 79 into which the engaging portion 68 of the turntable 67 is removably inserted and engaged from a central portion thereof. Is installed below.
By the way, since the clamper 72 is driven to rotate by the turntable 67, a clearance (gap) is formed between the clamper 72 and the equipment hole 71 so as not to hinder the rotation.

At the time of reproducing the CD 61, FIG.
As shown in FIG. 8, when the equipment hole 71 of the frame 70 and the center of the clamper 72 are aligned in the radial direction,
As shown in FIG. 19, when the reproducing unit 63 is moved up by the cam mechanism 65, as shown in FIG.
And the turntable 67 are magnetically attracted, the engaging portion 68 of the turntable 67 is engaged with the engaged portion 79 of the clamper 72, and the clamper 72 and the turntable 67
The CD 61 is smoothly clamped without any problem, and the CD 61 and the clamper 72 are lifted in a horizontal state by the turntable 67. In this state, the CD 61 is driven to rotate together with the clamper 72 to reproduce the CD 61.

However, as shown in FIG. 21, when the mounting hole 71 of the frame 70 and the center of the clamper 72 do not coincide with each other in the radial direction, as shown in FIG. As it rises, Figure 23
As shown in FIG. 7, the engaging portion 68 of the turntable 67 does not engage with the engaged portion 79 of the clamper 72, and the frame 7 is tilted with the turntable 67 inclined.
May lift from zero. In such a case, C
The clamping operation of the D61 is not performed smoothly, and a clamping error of the CD61 occurs, or the clamper 72 lifted in an inclined state slides on the turntable 67, and engages with the engaging portion 68 of the turntable 67 and the clamper. There is a problem that the engaged portions 79 of the 72 are suddenly engaged and generate a loud clamping sound.

Conventionally, when assembling the clamper 72, the claws 77 of the holder 73 are made to correspond to the holes 78 of the yoke 75, and then the claws 77 are elastically deformed radially inward. It is necessary to perform a cumbersome operation of inserting the holder 73 into the hole 78, and the bottom wall of the holder 73 and the yoke 75 are larger in the clamper 72 than the mounting hole 71. In the state where the clamper 72 is inserted into the equipment hole 71, it is necessary to perform the above-mentioned troublesome work.

Further, in the above-described conventional art, the yoke 7 prevents the clamper 72 from falling down from the equipment hole 71.
5, the holder 73, the magnet 74, and the yoke 75 are integrated by inserting and engaging the claw 77 of the holder 73 with the yoke 75. for that reason,
The yoke 75 is an essential component of the clamper 72,
Even when the yoke 75 is unnecessary, there is a problem that the yoke 75 cannot be omitted and the number of components of the clamper 72 cannot be reduced.

[0009]

SUMMARY OF THE INVENTION According to the present invention, claim 1 is included.
In the described invention, even if the center of the equipment hole and the clamper are shifted,
The displacement can be eliminated, and thereby the CD clamping operation can be performed smoothly, and the large clamping caused by the CD clamping error or the sudden engagement between the engaging portion of the turntable and the engaged portion of the clamper. An object of the present invention is to provide a disk clamp mechanism of a disk recording / reproducing apparatus which can prevent generation of sound. In addition to the above objects, the invention according to claim 2 can easily assemble the clamper and assemble the clamper to the frame in a short time, and when the yoke is unnecessary, can omit the yoke, so that parts of the clamper can be omitted. The goal is to be able to reduce points.

[0010]

Means for Solving the Problems In order to achieve the above object, of the present invention, the feature of the invention described in claim 1 is that A.I. A turntable on which a disk is mounted, the disk is driven to rotate, and an engagement portion is formed,
B. B. a frame disposed above the turntable and having an equipment hole formed vertically above the turntable; It has a clamper that is inserted into the equipment hole, is held by the frame, and has an engaged portion formed, and the clamper and the turntable are magnetically attracted by the relative approach of the frame and the turntable, and the turntable In the disc clamping mechanism of the disc recording / reproducing apparatus in which the disc is clamped from above and below by the turntable and the clamper, the equipment hole and the center of the clamper are matched. A centering mechanism is provided concentrically with the equipment hole; A groove formed in an arc shape on one of the frame and the clamper and having a substantially V-shaped cross section;
β. At the other of the frame and the clamper are arranged at substantially equal intervals in the circumferential direction, and are slidable with respect to the inner surface of the groove,
It is characterized by comprising three or more sliding parts which are in contact with the bottom of the inner surface of the groove when the equipment hole and the center of the clamper are aligned.
A feature of the invention according to claim 2 is that a groove is formed on the upper surface of the frame, and the clamper is provided with an A.C. B. a holder opening upward; The holder has a magnet fitted from above. A plurality of magnets are arranged at substantially equal intervals in the circumferential direction, and by elastic deformation in the radial direction, fitting of the magnet into the holder is allowed, and after the fitting, the magnet is detachably engaged with the magnet upper surface side, A retaining part that prevents the magnet from coming off the holder,
β. It is erected and has a sliding portion at the tip, allowing elastic insertion of the clamper into the equipment hole from below by elastic deformation in the radial direction. The point is that a projection for holding the clamper is formed on the frame. Note that the recording / reproduction means recording and / or
Or it means regeneration. Also, "the cross section of the groove is substantially V-shaped"
Means that the inner surface of the groove portion is located on the inner peripheral side and is inclined so as to move upward as it goes inward in the radial direction, and the inclined surface is located on the outer peripheral side and radially outward. And an upwardly inclined outer-peripheral-side inclined surface that moves upward. " In this case, the inclination angle and the width of the inner peripheral side inclined surface and the outer peripheral side inclined surface may not be the same.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention applied to a CD player will be described with reference to FIGS. 1 to 16. In FIGS. It includes a case (not shown), a tray 1, a reproducing unit 2, a frame (arm) 3, a clamper 4, a centering mechanism 5, and the like.

The tray 1 is formed with a circular concave portion 8 on which the CD 7 is placed, and the tray 1 is provided in the outer case so as to be movable in the front-rear direction. As shown in FIG. The position can be freely changed between a mounting / dismounting position which projects forward and where the CD 7 is attached and detached, and a reproducing position where the CD 7 is reproduced and stored in the outer case as shown in FIG.

The reproducing unit 2 reproduces a CD7.
A mounting plate 11 provided at the rear end of the mounting plate 11 so as to be vertically swingable via a support shaft 10 in a horizontal direction, and a spindle provided at a front portion of the mounting plate 11 and having a drive shaft (not shown) projecting upward. A motor 12, a turntable 13 fixed to a drive shaft and driven to rotate by the motor 12,
It has an optical pickup 14 and the like provided at the rear of the mounting plate 11.

A driven portion 16 projects forward from the front end of the mounting plate 11, and is driven by the cam groove 1 of the cam body 17.
8 and the cam body 17 is driven to rotate,
The reproducing section 2 is driven to swing up and down to reproduce the CD 7 as shown in FIG. 11, and a position below the reproducing position and a position at the time of movement of the tray 1 as shown in FIG. The position can be freely changed to a standby position. The turntable 13 includes a shaft portion 20 on the center portion side and a table portion 21 fixed to the shaft portion 20 and on which the CD 7 is mounted. A concave portion 22 that opens upward is formed in the center portion of the shaft portion 20. Then, a round shaft-shaped engaging portion 23 is erected at the center of the concave portion 22, and the table portion 21 has a ferromagnetic material (magnetic material) such as an iron plate. Incidentally, the engagement portion 23 may be a drive shaft of the spindle motor 12 in some cases.

The frame 3 is disposed above the turntable 13. The frame 3 has an equipment hole 25 located above the turntable 13 formed vertically therethrough, and a circular hole is formed on the upper surface of the frame 3. Groove (circumferential groove, V groove)
26 is formed horizontally concentrically with the equipment hole 25 and adjacent to the outer side in the radial direction. The groove portion 26 has a substantially V-shaped cross section that opens upward, and the inner surface thereof has an inner peripheral side inclined surface 27 that is located on the inner peripheral side and is inclined so as to move upward as it goes radially inward. , An outer peripheral side inclined surface 28 which is located on the outer peripheral side and is inclined so as to move upward as it goes radially outward. In the illustrated example, the width of the inner peripheral side inclined surface 27 is about half of the outer peripheral side inclined surface 28. Further, there are cases where the inclination angles of both inclined surfaces 27 and 28 are the same and cases where they are not.

The clamper 4 is inserted from below into the equipment hole 25 and is held by the frame 3.
The CD 7 is removably clamped together with the turntable 13 from above and below, and is rotationally driven by the turntable 13 together with the CD 7. The clamper 4 includes a cylindrical holder 30 that opens upward, a magnet 31 and a yoke 32 that are fitted into the holder 30.

The holder 30 is made of an elastically deformable hard plastic resin and has an inner cylindrical portion 34 that opens downward.
An engaged portion 35 provided below the central portion of the top wall of the inner cylindrical portion 34, and an outer cylindrical portion 36 which is disposed concentrically outside the inner cylindrical portion 34 and opens vertically, Three connecting portions 37 which are arranged in the circumferential direction at (substantially) equal intervals and connect the lower ends of the two cylindrical portions 34 and 36; And four first notches 39 formed on the outer cylindrical portion 36 and arranged at (approximately) equal intervals in the circumferential direction. And two second notches 40 forming an angle of 120 degrees with a predetermined one first notch 39;
It comprises a projection 41 erected from the bottom of the notch 39 and three retaining portions 42, 43 and the like.

The engaged portion 35 is engaged with the engaging portion 23 of the turntable 13 so as to be freely engaged and disengaged. The engaged portion 35 has a cylindrical shape that opens downward, and has a lower end surface tapered upward. A tapered surface 45 is provided. The outer diameter of the protruding portion 38 is set to be larger than the diameter of the equipment hole 25 to prevent the holder 30 from dropping upward.

The projection 41 is elastically deformable in the radial direction, and has an upright portion 47 standing upright from the first cutout portion 39;
It is composed of a connecting portion 48 protruding radially outward from the upper end of the standing portion 47 and a sliding portion 49 protruding radially outward from the tip of the horizontal portion 48. The sliding portion 49 is inclined so as to move downward as it goes radially outward. Each sliding portion 49 is inserted into the groove 26 of the frame 3, and the sliding hole 49 and the groove 26 allow the equipment hole 25 to be inserted.
And a centering mechanism 5 which is concentric with the center of the equipment hole 25 and the clamper 4. Each sliding portion 49 is slidable with respect to the inner surface of the groove 26, and the groove 2 is aligned with the center of the equipment hole 25 and the clamper 4.
6 is in contact with the bottom of the inner surface, that is, the lower part of both inclined surfaces 27 and 28 of the groove 26.

The inclination angle of each sliding portion 49 is the same (substantially the same) as the inclination angle of the inner peripheral side inclined surface 27 of the groove 26 or is steeper than the inclination angle of the inner peripheral side inclined surface 27. ing. or,
As shown in FIG. 7, when the holder 30 is inserted into the equipment hole 25 from below, as shown in FIG. Since the holder 30 is easily elastically deformed inward in the direction, the holder 30 can be easily inserted into the equipment hole 25, and after the insertion, each sliding portion 49 abuts on the inner surface of the groove 26, and the clamper 4 is suspended from the frame 3. It is kept in the shape.

The retaining portions 42 and 43 are arranged at (approximately) equal intervals in the circumferential direction on the holder 30. Of the three retaining portions 42 and 43, one of the retaining portions 42 is a side surface. The projection 41 is formed in a triangular shape, and protrudes radially inward from the standing portion 47 of the projection 41 standing upright from the predetermined one first notch 39. Also, the other two retaining portions 43
Is erected from the bottom of the second notch 40, and the tip is triangular in side view, protrudes inward in the radial direction, and is elastically deformable in the radial direction. As the upper surfaces of the retaining portions 42 and 43 move inward in the radial direction,
The inclined surface 51 is shifted downward. Note that the retaining portion 42 may not be formed on the projection 41 but may be formed on the holder 30 similarly to the other retaining portions 43.

The magnet 31 and the yoke 32 are formed in a disk shape, inserted into the holder 30 from above in the above order, and fitted with the inner and outer cylindrical portions 34 and 36. Sometimes, the magnet 31 and the yoke 32 come into contact with the inclined surfaces 51 of the retaining portions 42, 43, while elastically deforming the projection 41 having the retaining portion 42 and the retaining portion 43 radially outward. , Holder 3
After the insertion, the lower surfaces of the retaining portions 42 and 43 are engaged with the upper surface of the yoke 32 to prevent the magnet 31 and the yoke 32 from coming out of the holder 30 upward. In some cases, the yoke 32 is not provided in the clamper 4. In this case, the retaining portions 42 and 43 directly engage the upper surface of the magnet 31.

According to the first example constructed as described above, when assembling the clamper 4 and assembling it to the frame 3, FIG.
8, after the holder 30 is inserted into the equipment hole 25 from below while elastically deforming the projection 41, the projection 41 having the retaining portion 42 and the retaining portion 43 are elastically deformed. However, the magnet 31 and the yoke 32 may be fitted into the holder 30. Thus, in the present invention, when assembling the clamper 4 and assembling it to the frame 3, as in the conventional example shown in FIGS.
There is no need to perform troublesome positioning or the like, and the assembly and assembly of the clamper 4 can be performed easily and in a short time.

Also, the holder 30 prevents the clamper 4 from falling down from the equipment hole 25,
Since the retaining portion of the holder 30 is merely engaged with the upper surface of the yoke 32 or the magnet 31, the yoke 3
2 is not an essential component of the clamper 4 and the yoke 3
In the case where 2 is unnecessary, the yoke 32 can be omitted, and the number of parts of the clamper 4 can be reduced.

The reproduction of the CD7 is performed as follows. That is, as shown in FIG. 2, after the CD 7 is placed in the circular concave portion of the tray 1 in a state where the tray 1 is located at the attaching / detaching position located in front of the reproducing unit 2 and the frame 3,
The tray 1 is moved to the rear reproduction position, and is located between the reproduction unit 2 and the frame 3.

Then, as shown in FIG.
When the center of the equipment hole 25 of the frame 3 coincides with the center in the radial direction, the rotation of the cam body 17 causes
As shown in FIG. 10, when the reproducing unit 2 is driven to swing upward, as shown in FIG.
The CD 7 is lifted upward. Further, the upper end of the shaft portion 20 of the turntable 13 enters the inner cylindrical portion 34 of the clamper 4 by the swing of the reproducing unit 2 and the magnetic attraction of the turntable 13 by the magnet 31 of the clamper 4.

Further, the engaging portion 23 of the turntable 13
Enters the engaged portion 35 while being guided by the tapered surface 45 of the engaged portion 35 of the clamper 4, and engages with the engaged portion 35 as shown in FIG. The magnet 31 and the turntable 13 are magnetically attracted, and the CD 7
Is smoothly and smoothly clamped by the clamper 4 and the turntable 13 without any problem.
The CD 7 and the clamper 4 are lifted in a horizontal state. Then, the CD 7 and the clamper 4 are rotationally driven by the spindle motor 12 via the turntable 13, and the CD 7 is reproduced by the optical pickup 14 or the like.

When the CD 7 is clamped, the center of the clamper 4 and the mounting hole 25 of the frame 3 may be shifted in the radial direction for some reason, as shown in FIGS. In this case, some of the four sliding portions 49 of the holder 30 abut against the inner peripheral inclined surface 27 of the groove 26 of the frame 3, and others contact the outer peripheral inclined surface 28. It will be in a state of having done. However, even in this case, due to the own weight of the clamper 4, as shown in FIG.
Slides downward on the inner peripheral side inclined surface 27 or the outer peripheral side inclined surface 28, that is, toward the bottom of the groove 26, and the clamper 4 moves in the radial direction, as shown in FIG. The centers of the clamper 4 and the equipment hole 25 are aligned.

Next, a first example of the embodiment of the present invention will be compared with a comparative example shown in FIG. In the comparative example, frame 3
The inner surface of the upper part of the equipment hole 25 and the outer peripheral surface of the upper part of the clamper 4 have tapered surfaces 52, 5 tapering downward.
3, a centering mechanism 5 according to the present invention is configured. By the way, in the comparative example, as shown in FIG.
When the center between the clamper 4 and the equipment hole 25 is displaced, the tapered surface 53 of the clamper 4 is hooked on the tapered surface 52 of the equipment hole 25, and the left end side (toward FIG. 17) of the clamper 4 does not move upward. And the center of the clamper 4 and the equipment hole 25 do not match. However, depending on the frictional force between the clamper 4 and the inner surface of the equipment hole 25, the above movement may not be allowed. In this case, the center of the clamper 4 and the equipment hole 25 remain off-center.

On the other hand, in the first embodiment of the present invention,
As shown in FIG. 15, with the clamper 4 inclined,
When the center of the equipment hole 25 of the clamper 4 and the frame 3 is displaced, some of the sliding portions 49 come into contact with the inner peripheral inclined surface 27 or the outer peripheral inclined surface 28 of the groove 26. However, others are separated from the inner surface of the groove 26. However, even in this case, due to the weight of the clamper 4, the sliding portion 49 in contact with the inner surface of the groove 26 slides downward while returning the clamper 4 to the horizontal position, and as shown in FIG. 4 and the center of the equipment hole 25 are matched,
Unlike the comparative example, the centers of the clamper 4 and the equipment hole 25 do not remain shifted. As described above, the equipment hole 25
The centering mechanism 5
As a result, the displacement can be eliminated, so that the clamping operation of the CD 7 can be performed smoothly, and the CD 7 is erroneously clamped or the engaging portion 23 of the turntable 13 and the engaged portion 35 of the clamper 4 are suddenly engaged. , It is possible to prevent generation of a loud clamping sound.

FIG. 16 shows a second embodiment of the present invention. Four sliding portions 49 erected on the upper surface of the frame 3 radially outward of the mounting holes 25 are provided in the circumferential direction. They are arranged at equal intervals. In the clamper 4, the protrusion 41 of the holder 30 has an inverted L shape, and the protrusion 41 has no horizontal portion or sliding portion 49. Further, the holder 30 is not formed with the second cutout portion 40 and the retaining portion. The yoke 32 has a larger diameter than the equipment hole 25, and the protrusion 41 is inserted into the hole 55 through elastic deformation inward in the radial direction, and is engaged with the upper surface of the yoke 32, thereby holding the yoke 32. 30, a magnet 31, and a yoke 32 are integrated. A groove 26 that opens downward is formed in the outer peripheral portion of the yoke 32, and the sliding portion 49 of the frame 3 abuts on the inner surface of the groove 26 so as to be slidable in the width direction.

In the embodiment of the present invention, a circular groove is formed in the frame or the yoke. However, the groove does not have to be completely circular. For example, only a portion where the sliding portion slides has an arc shape. The groove may be formed, and the groove may not be formed in other portions. Further, in the above-described embodiment, the number of the sliding portions is four, but the number of the sliding portions may be three or more. Furthermore, in the first example of the above embodiment, the number of retaining portions is three, but the number of retaining portions may be plural. However, in order to sufficiently fulfill the retaining function, it is preferable that the number of retaining portions is three or more. In the above embodiment, the present invention is applied to a CD player, but the present invention is also applicable to a DVD (digital video disc) player and the like.

[0033]

As described in detail above, according to the present invention,
Even if the center of the equipment hole and the clamper are shifted, the shift can be resolved. Accordingly, the CD clamping operation can be performed smoothly, and it is possible to prevent the generation of a loud clamping sound due to a CD clamping error and a sudden engagement between the engaging portion of the turntable and the engaged portion of the clamper. In addition to the above effects, the invention according to claim 2 can easily assemble the clamper and assemble the clamper to the frame in a short time, and can omit the yoke when the yoke is not required, thereby reducing the parts of the clamper. Points can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part showing a first example of an embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of a main part showing a first example of an embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a main part showing a first example of an embodiment of the present invention.

FIG. 4 is an exploded perspective view of a main part of FIG.

FIG. 5 is an enlarged view of a main part of FIG. 3;

FIG. 6 is a longitudinal sectional view of a main part showing a first example of an embodiment of the present invention.

FIG. 7 is a vertical sectional view showing a state before the insertion of the clamper of FIG. 5;

8 is a vertical sectional view showing a state when the clamper of FIG. 5 is inserted.

FIG. 9 is an operation state diagram of FIG. 3;

FIG. 10 is an operation state diagram of FIG. 3;

FIG. 11 is an operation state diagram of FIG. 3;

FIG. 12 is a longitudinal sectional view showing a state in which the center of the clamper and the equipment hole in FIG. 3 are shifted from each other.

FIG. 13 is an enlarged view of a main part of FIG.

FIG. 14 is an operation state diagram of FIG.

FIG. 15 is a longitudinal sectional view showing a state in which the clamper is inclined and the center of the equipment hole is shifted from that of FIG. 5;

FIG. 16 is a longitudinal sectional view of a main part showing a second example of the embodiment of the present invention.

FIG. 17 is an explanatory diagram of a main part showing a comparative example of the present invention.

FIG. 18 is a longitudinal sectional view of a main part showing an example of the related art.

FIG. 19 is an operation state diagram of FIG. 18;

FIG. 20 is an operation state diagram of FIG. 18;

FIG. 21 is a longitudinal sectional view showing a state in which the centers of the clamper and the equipment hole are shifted from each other in FIG. 18;

FIG. 22 is an operation state diagram of FIG. 21;

23 is an operation state diagram of FIG. 21.

[Explanation of symbols]

2 Reproduction part 3 Frame 4 Clamper 5 Centering mechanism 7 CD 13 Turntable 23 Engagement part 25 Equipment hole 26 Groove part 30 Holder 31 Magnet 35 Engagement part 41 Projection 42, 43 Retaining part 49 Sliding part

Claims (2)

[Claims] 1. A. First Embodiment B. a turntable on which the disk is mounted, the disk is driven to rotate, and an engagement portion is formed; B. a frame disposed above the turntable and having an equipment hole vertically formed above the turntable; It has a clamper that is inserted into the equipment hole, is held by the frame, and has an engaged portion formed. By the relative approach of the frame and the turntable, the clamper and the turntable are magnetically attracted to the turntable. In the disc clamping mechanism of the disc recording / reproducing apparatus in which the disc is clamped from above and below by the turntable and the clamper while the engaging portion of the clamper is engaged with the engaged portion of the clamper, the equipment hole and the center of the clamper are aligned. A centering mechanism is provided concentrically with the equipment hole; It is formed in an arc shape on one of the frame and the clamper,
A groove having a substantially V-shaped cross section; β. At the other of the frame and the clamper are arranged at substantially equal intervals in the circumferential direction, and are slidable with respect to the inner surface of the groove,
A disc clamping mechanism for a disc recording / reproducing apparatus, comprising three or more sliding portions that abut the bottom of an inner surface of a groove when the mounting hole and the center of the clamper are aligned. 2. A groove is formed on the upper surface of the frame, and the clamper comprises: B. a holder opening upward; It has a magnet fitted from above in the holder. A plurality of magnets are arranged at substantially equal intervals in the circumferential direction, and by elastic deformation in the radial direction, fitting of the magnet into the holder is allowed, and after the fitting, the magnet is detachably engaged with the magnet upper surface side. A retaining portion for preventing the magnet from coming off the holder, β. It is erected, has a sliding part at the tip, and allows the clamper to be inserted into the equipment hole from below by elastic deformation in the radial direction, and after the insertion, through the sliding part 2. The disk clamp mechanism for a disk recording / reproducing apparatus according to claim 1, wherein a projection for holding the clamper is formed on the frame.