JPH08147836A - Turntable device shared for cd/md - Google Patents

Abstract

PURPOSE: To provide a turntable device shared for CD/MD by using a turntable provided with required three kinds of surface supporting means and a magnet, etc., and a clamper. CONSTITUTION: The inner peripheral surface 6 of the CD 5 is supported by the outer peripheral wall part 7 of the first surface supporting means of the turntable 3 provided with the magnet 9. On the other hand, the outer wall of the projected wall part 10 of the clamper 4 of a steel plate supported by the inner peripheral wall surface 8 of the table 3 is abutted on the inner peripheral wall of the CD 5, and the upper surface of the inner peripheral part 6 of the CD 5 is pressed by the bottom surface of the outer peripheral part 12 of the clamper 4, and then, the CD 5 is loaded on the table 3. On the other hand, similarly the MD 13 housed in a rectangular shaped cartridge 14 is loaded on the table 3 integrally with the cartridge 14 by a second circular surface supporting means formed on the inside of the wall part 7 of the table 3 and the outer peripheral wall surface, etc., of the wall 8 of the table 3 becoming a third surface supporting means, and the turntable shared for CD/MD is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined CD / MD turntable device.

[0002]

2. Description of the Related Art FIG. 5 is a diagram schematically showing the structure of a conventional CD (compact disc) turntable device. The turntable device shown in FIG.
It has a turntable 53 fixed to the output shaft 52. In FIG. 5, only the central portion of the CD 55 is shown for clarity. CD55 and turntable 5
3 is a disk shape as a whole, and the inner peripheral portion 5 of the CD 55
The inner peripheral wall surface of 6 and the outer peripheral wall surface of the annular straight wall portion 59 of the turntable 53 are in contact with each other. Also, CD5
The lower surface of the portion 57 of 5 is the outer peripheral portion 58 of the turntable 53.
Are abutted and supported.

As described above, the positioning of the CD 55 in the vertical direction (height direction) in the figure is performed by the contact between the lower surface of the portion 57 of the CD 55 and the outer peripheral portion 58 of the turntable 53. The center positioning of the CD 55 with respect to the spindle motor 51 is performed by abutting the outer peripheral wall surface of the straight wall portion 59 of the turntable 53 centered with respect to the spindle motor 51 and the inner peripheral wall surface of the inner peripheral portion 56 of the CD 55. It The outer peripheral portion 60 of the clamper 54, which is biased downward in the figure, presses the upper surface of the portion 57 of the CD 55, and this portion 57 is placed between the outer peripheral portion 59 of the turntable 53 and the outer peripheral portion 60 of the clamper 54. C
D55 is securely clamped and held on the turntable 53.

FIG. 6 is a diagram schematically showing the structure of a conventional MD (magneto-optical disk) turntable device. The turntable device shown in FIG. 6 includes a turntable 63 fixed to an output shaft 62 of a spindle motor 61.
Note that, also in FIG. 6, only the central portion of the MD 64 is shown for the sake of clarity. The MD 64 includes a cartridge 65 having a generally rectangular shape, a disk substrate 66 housed in the cartridge 65, and a magnetic material portion 67 attached to an inner peripheral portion of the disk substrate 66.

On the other hand, the turntable 63 has a disc shape as a whole, and the inner peripheral wall surface of the inner peripheral portion 68 of the disc substrate 66 of the MD 64 and the outer peripheral wall surface of the annular straight wall portion 69 of the turntable 63 are in contact with each other. Has become. Further, the lower surface of the inner peripheral portion 68 of the disc substrate 66 of the MD 64 is brought into contact with and supported by the outer peripheral portion 70 of the turntable 63. As described above, the MD 64 is positioned in the vertical direction (height direction) in the figure by the contact between the lower surface of the inner peripheral portion 68 of the disc substrate 66 of the MD 64 and the outer peripheral portion 70 of the turntable 63. The centering of the MD 64 with respect to the spindle motor 61 is performed by abutting the outer peripheral wall surface of the straight wall portion 69 of the turntable 63 centered with respect to the spindle motor 61 and the inner peripheral wall surface of the inner peripheral portion 68 of the MD 64. It

The turntable 63 is provided with an MD chucking magnet 71. Then, the magnet 71 attracts the magnetic body portion 67 attached to the inner peripheral portion of the disc substrate 66 of the MD 64,
The MD 64 is reliably positioned and held on the turntable 63.

[0007]

As described above, the shape of the clamp area of the disc is different between the CD and the MD. As a result, the conventional CD turntable device and MD
The structure of the turntable is different from that of the turntable device. Therefore, there is a disadvantage that the conventional turntable device cannot support both the CD and the MD, even though the CD and the MD share the same reading method of the recorded information. The present invention has been made in view of the above problems, and an object of the present invention is to provide a combined CD / MD turntable device capable of positioning and holding both a CD and an MD.

[0008]

In order to solve the above-mentioned problems, in the present invention, a turntable fixed to the output shaft of the rotary drive means and a clamper means capable of urging toward the turntable are provided. In a turntable device provided with the turntable, the turntable has a first surface supporting means for abutting and supporting the lower surface of the inner peripheral portion of the CD, and a second surface for abutting and supporting the lower surface of the inner peripheral portion of the MD. Supporting means, a third surface supporting means for abutting and supporting the inner peripheral wall surface of the inner peripheral portion of the MD or the outer peripheral wall surface of the inner peripheral portion, and a magnetic body portion of the disk substrate of the MD for attracting and biasing. The clamper means includes a magnet means, and the clamper means presses the upper surface of the inner peripheral portion of the CD in contact with and supports the inner peripheral wall surface of the inner peripheral portion of the CD and the upper surface of the inner peripheral portion of the CD. And an outer peripheral portion for Providing apparatus characterized.

According to a preferred embodiment of the present invention, the first
The surface supporting means is an upper end surface of an outer peripheral straight wall portion formed on the outer peripheral portion of the turntable, and the second surface supporting means is an annular surface supporting portion formed inside the outer peripheral straight wall portion, The third surface support means is an outer peripheral wall surface of an inner peripheral straight wall portion or an inner peripheral wall surface of the outer peripheral straight wall portion formed inside the annular surface support portion, and the fourth surface support means is provided from the clamper means to the turntable. It is the outer peripheral wall surface of the straight wall portion extending to the side.

According to another aspect of the present invention, there is provided a turntable device including a turntable fixed to an output shaft of a rotation driving means, and a clamper means capable of urging toward the turntable. The table is a CD
In the positioning and holding state, the lower surface of the inner peripheral portion of the CD abuts and supports, and in the positioning and holding state of the MD, the first surface supporting means for abutting and supporting the lower surface of the disc substrate of the MD and the inner peripheral surface of the MD. Second for abutting and supporting the inner peripheral wall surface of the section
A surface supporting means and a magnet means for attracting and urging the magnetic body portion of the MD disk substrate are attracted, and the clamper means contacts the inner peripheral wall surface of the inner peripheral portion of the CD or the outer peripheral wall surface of the inner peripheral portion. (EN) An apparatus provided with a third surface supporting means for contacting and supporting, and an outer peripheral portion for pressing the upper surface of the inner peripheral portion of the CD when the CD is positioned and held.

According to a preferred embodiment of the present invention, the first
The surface support means is an upper end surface of the outer peripheral straight wall portion formed on the outer peripheral portion of the turntable, and the second surface support means is the outer peripheral wall surface of the inner peripheral straight wall portion formed inside the annular surface support portion or the above. It is the inner peripheral wall surface of the outer peripheral straight wall portion, and the third surface supporting means is the outer peripheral wall surface of the straight wall portion extending from the clamper means to the turntable side.

[0012]

In the turntable device of the present invention, the lower surface of the inner peripheral portion of the CD is contacted and supported to position the CD in the height direction, and the lower surface of the inner peripheral portion of the MD is contacted and supported. MD
An MD surface support portion for positioning the ‘A’ in the height direction is separately formed on the turntable. Alternatively, when the CD is positioned and held, the lower surface of the inner peripheral portion of the CD is abutted and supported, and when the MD is positioned and held, the lower surface of the disc substrate of the MD is abutted and supported, and both the CD and the MD are height-wise A common surface supporting portion for positioning is formed on the turntable.

Then, a surface supporting portion for contacting and supporting the inner peripheral wall surface of the inner peripheral portion of the MD and centering the MD is formed in the clamper means and supporting and supporting the inner peripheral wall surface of the inner peripheral portion of the CD. C
A surface support for centrally positioning D is formed on the turntable. Thus, in the turntable device of the present invention, both the CD and the MD can be positioned and reliably held in the height direction and the center direction.

[0014]

Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a CD / M according to a first embodiment of the present invention.
It is sectional drawing which illustrates typically the structure of the D combined turntable apparatus, (a) shows the state which hold | maintained CD, (b)
Indicates a state in which the MD is held. The apparatus of FIG. 1 comprises a turntable 3 fixed to an output shaft 2 of a spindle motor 1 and a clamper 4. In FIGS. 1A and 1B, the turntable 3 and the clamper 4 have the same shape.

First, in FIG. 1 (a), the turntable 3 is generally disc-shaped, and has an outer peripheral straight wall portion 7 that abuts and supports the lower surface of the inner peripheral portion 6 of the CD 5. More specifically, the outer peripheral straight wall portion 7 has a generally cylindrical shape, and the inner peripheral portion 6 of the CD 5 is abutted and supported on the upper end surface thereof. Further, the turntable 3 is formed with an inner peripheral straight wall portion 8 protruding upward. The inner peripheral straight wall portion 8 is also entirely cylindrical, and a magnet 9 is provided inside thereof.

On the other hand, the clamper 4 is also disk-shaped as a whole and has a protruding straight wall portion 10 extending downward. The straight wall portion 10 has a generally cylindrical shape, and when the CD 5 is clamped as shown in the figure, the inner peripheral wall surface of the straight wall portion 10 abuts the outer peripheral wall surface of the inner peripheral straight wall portion of the CD 5 and, at the same time, the clamper 4 is pressed.
The lower surface of the outer peripheral portion 12 is pressed against the upper surface of the inner peripheral portion 6 of the CD 5. Further, the outer peripheral wall surface of the straight wall portion 10 is C
The inner peripheral wall surface of the inner peripheral portion 6 of D5 is in contact with.

Further, an iron plate 11 is attached to the inside of the straight wall portion 10 of the clamper 4, and the iron plate 11 is extended by the action of the magnet 9 of the turntable 3.
The whole is attracted and biased toward the turntable 3. When the clamper 4 is biased toward the turntable 3 by using another biasing means such as a spring, the iron plate 11 is not always necessary.

In this way, the CD 5 is positioned in the height direction (vertical direction in the drawing) by contact between the upper end surface of the outer peripheral straight wall portion 7 of the turntable 3 and the lower surface of the inner peripheral portion 6 of the CD 5. Further, the centering (centering) of the CD 5 with respect to the center axis of the output shaft 2 of the spindle motor 1 is performed by the straight wall portion of the clamper 4 fitted onto the inner peripheral straight wall portion 8 of the turntable 3 centered by the output shaft 2. The contact is made between the outer peripheral wall surface 10 and the inner peripheral wall surface of the inner peripheral portion 6 of the CD 5. Further, the chucking of the CD 5 is achieved by sandwiching the inner peripheral portion 6 of the CD 5 between the outer peripheral straight wall portion 7 of the turntable 3 and the outer peripheral portion 12 of the clamper 4. The CD 5 may be positioned and held more stably by enlarging the diameter of the clamper 4 as shown by the broken line in the figure.

On the other hand, referring to FIG. 1B, the MD 13 is positioned and held on the turntable 3.
The MD 13 has a cartridge 14 that is generally rectangular. A disk substrate 15 on which information is recorded is housed in the cartridge 14. Disk substrate 15
Has a disc shape as a whole, and an annular magnetic body portion 17 is formed adjacent to the inner peripheral portion 16 thereof. Magnetic body part 17
The inner peripheral end 18 of the magnet covers the magnet 9 provided on the turntable 3.

As shown in the figure, when the MD 13 is positioned and held, the MD 13 and the upper surface of the generally annular surface support portion 19 formed inside the outer peripheral straight wall portion 7 of the turntable 3.
The lower surface of the inner peripheral portion 16 of the disk substrate 15 is in contact with. Further, the inner peripheral wall surface of the inner peripheral portion 16 of the disc substrate 15 of the MD 13 comes into contact with the outer peripheral wall surface of the inner peripheral straight wall 8 of the turntable 3, whereby the disc substrate 1
5 is centered (centered). It should be noted that instead of abutting the inner peripheral wall surface of the inner peripheral portion 16 and the outer peripheral wall surface of the inner peripheral straight wall 8, the inner peripheral wall surface of the outer peripheral direct wall portion 7 and the outer peripheral wall surface of the inner peripheral portion 16 are brought into contact with each other so that the disk substrate Fifteen may be centered. In this case, by appropriately chamfering the inside of the outer peripheral straight wall portion 7, it becomes easy to mount the disc substrate 15 on the turntable. Further, by the action of the magnet 9 of the turntable 3, the magnetic body portion 17 and thus the disk substrate 15 are attracted and biased toward the turntable 3.

Thus, the positioning of the MD 13 in the height direction (vertical direction in the figure) is performed by the surface support portion 19 of the turntable 3.
And the lower surface of the inner peripheral portion 16 of the disc substrate 15 of the MD 13 are brought into contact with each other. Further, centering (centering) of the MD 13 with respect to the central axis of the output shaft 2 of the spindle motor 1 is performed by centering the MD 13 with the outer peripheral wall surface of the inner peripheral straight wall portion 8 of the turntable 3 and the MD.
13 by contact with the inner peripheral wall surface of the inner peripheral portion 16 of the disk substrate 15.

Further, the chucking of the MD 13, that is, the positioning of the cartridge 14 is performed by a fixing means (not shown), and the chucking of the disk substrate 15 turns the magnetic body portion 17 by the action of the magnet 9 of the turntable 3. This is accomplished by biasing the suction towards the table 3. The straight wall portion 1 of the clamper 4
The lower surface of 0 may be pressed against the upper surface of the cartridge 14 of the MD 13 to more stably position and hold the cartridge 14 of the MD 13.
Thus, according to the device of the first embodiment, both the CD and MD can be positioned and held by the common mechanism. In this embodiment, in order to match the height of the lower surface of the CD 5 with the height of the lower surface of the disc substrate 15, the height of the outer peripheral straight wall portion 7 is set to the protrusion amount of the inner peripheral portion 16 from the disc substrate 15. It should almost match.

FIG. 2 shows C according to the second embodiment of the present invention.
It is sectional drawing which illustrates typically the structure of a D / MD combined turntable device, (a) is the state which hold | maintained CD,
(B) shows a state in which the MD is held. Figure 2 (a)
In (b) and (b), the turntable 3 and the clamper 4 have the same shape. The apparatus of the second embodiment of FIG. 2 has the same structure as the apparatus of the first embodiment of FIG. 1, but in the apparatus of FIG. 2, the cylindrical portion 2 protruding downward in the center of the clamper 4 is used.
1 is basically different from the first embodiment.

Referring to FIG. 2A, in the state where the CD 5 is clamped and held, the columnar portion 21 of the clamper 4 is fitted in the through hole 22 formed in the central portion of the turntable 3. That is, the outer peripheral wall surface of the cylindrical portion 21 of the clamper 4 is in contact with the peripheral wall surface of the central through hole 22 having a central axis that coincides with the central axis of the output shaft 2 of the spindle motor 1. In this way, the center positioning of the CD 5 with respect to the center axis of the output shaft 2 of the spindle motor 1 is performed by positioning the outer peripheral wall surface of the straight wall portion 10 of the clamper 4 and the inner peripheral wall surface of the inner peripheral portion 6 of the CD 5 centered by the cylindrical portion 21. It is made by abutting with. Therefore, in this embodiment, the outer peripheral wall surface of the inner peripheral straight wall 8 of the turntable 3 and the inner peripheral wall surface of the straight wall portion 10 of the clamper 4 do not necessarily have to be in contact with each other.

The positioning of the CD 5 in the height direction and the chucking are the same as in the case of the apparatus of the first embodiment, and the duplicated description will be omitted. On the other hand, referring to FIG. 2B, the shape of the turntable 3 is similar to that of the turntable of the first embodiment. Therefore, MD1
The positioning in the height direction, the positioning in the center, and the chucking are the same as in the case of the device of the first embodiment, and the duplicated description will be omitted.

FIG. 3 shows a C according to the third embodiment of the present invention.
It is sectional drawing which illustrates typically the structure of a D / MD combined turntable device, (a) is the state which hold | maintained CD,
(B) shows a state in which the MD is held. FIG. 3 (a)
In (b) and (b), the turntable 3 and the clamper 4 have the same shape. The device of the third embodiment of FIG. 3 has the same configuration as the device of the first embodiment of FIG. 1, but in the device of FIG. 3, both the CD and the MD are hit by the upper end surface of the outer peripheral straight wall of the turntable 3. The point of contacting and supporting is basically different from that of the first embodiment. The height of the outer peripheral straight wall portion 7 is set to be substantially equal to or larger than the amount of protrusion of the inner peripheral portion 16 from the disk substrate 15.

Referring to FIG. 3A, the CD 5 is positioned in the height direction, centered and chucked by the first method.
This is the same as the case of the apparatus of the embodiment, and the duplicated description will be omitted. On the other hand, referring to FIG. 3B, the disc substrate 1 of the MD 13 in a state where the MD 13 is positioned and held.
A bottom surface 31 of the turntable 3 is abutted and supported by the upper end surface of the outer peripheral straight wall portion 7 of the turntable 3. In this way, the positioning of the disc substrate 15 of the MD 13 in the height direction is performed by contact between the lower surface of the disc substrate 15 of the MD 13 and the upper end surface of the outer peripheral straight wall portion 7 of the turntable 3. Therefore,
In this embodiment, both the CD and the MD are positioned at a common (same) height by the common contact support surface of the turntable 3, that is, the upper end surface of the outer peripheral straight wall 7. In addition, MD1
3 for centering and chucking
This is the same as the case of the apparatus of the embodiment, and the duplicated description will be omitted.

FIG. 4 shows C according to the fourth embodiment of the present invention.
It is sectional drawing which illustrates typically the structure of a D / MD combined turntable device, (a) is the state which hold | maintained CD,
(B) shows a state in which the MD is held. Figure 4 (a)
In (b) and (b), the turntable 3 and the clamper 4 have the same shape. The apparatus of the fourth embodiment shown in FIG. 4 has the same structure as the apparatus of the third embodiment shown in FIG. 3, but in the apparatus of FIG.
1 is basically different from the third embodiment.

Referring to FIG. 4A, in the state where the CD 5 is clamped and held, the columnar portion 21 of the clamper 4 is fitted in the central through hole 22 formed in the central portion of the turntable 3. That is, the outer peripheral wall surface of the cylindrical portion 21 of the clamper 4 is in contact with the peripheral wall surface of the through hole 22 having the central axis that coincides with the central axis of the output shaft 2 of the spindle motor 1. In this way, the center positioning of the CD 5 with respect to the center axis of the output shaft 2 of the spindle motor 1 is performed by positioning the outer peripheral wall surface of the straight wall portion 10 of the clamper 4 and the inner peripheral wall surface of the inner peripheral portion 6 of the CD 5 centered by the cylindrical portion 21. It is made by abutting with. Therefore, in this embodiment, it is not necessary that the outer peripheral wall surface of the inner peripheral straight wall 8 of the turntable 3 and the inner peripheral wall surface of the straight wall portion 10 of the clamper 4 contact each other.

The positioning of the CD 5 in the height direction and the chucking are the same as in the case of the apparatus of the third embodiment, and the duplicated description will be omitted. On the other hand, referring to FIG. 4B, the shape of the turntable 3 is similar to the shape of the turntable at the third time. Therefore, the positioning of the MD 13 in the height direction, the positioning of the center, and the chucking are the same as in the case of the device of the third embodiment, and a duplicate description will be omitted.

In the above description, the clamper 4 presses the cartridge 14 of the MD 13 when the MD is mounted, but when the cartridge 14 is fixed by means other than the clamper 4, the clamper 14 is not lowered. You may do it. With such a configuration, it is possible to prevent contact between the inner wall surface of the cartridge 14 and the disk substrate 15 without exerting an unreasonable force on the central portion of the cartridge 14.

[0032]

As described above, in the turntable device of the present invention, both the CD and MD can be positioned and held by the common mechanism.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically illustrating the configuration of a combined CD / MD turntable device according to a first embodiment of the present invention, in which (a) shows a state of holding a CD and (b) shows MD
Shows the state of holding.

2A and 2B are cross-sectional views schematically illustrating a configuration of a combined CD / MD turntable device according to a second embodiment of the present invention, in which FIG. 2A is a state in which a CD is held, and FIG. MD
Shows the state of holding.

3A and 3B are cross-sectional views schematically illustrating the configuration of a combined CD / MD turntable device according to a third embodiment of the present invention, in which FIG. 3A is a state in which a CD is held, and FIG. MD
Shows the state of holding.

4A and 4B are cross-sectional views schematically illustrating the configuration of a combined CD / MD turntable device according to a fourth embodiment of the present invention, where FIG. 4A is a state in which a CD is held, and FIG. MD
Shows the state of holding.

FIG. 5 is a cross-sectional view schematically illustrating the configuration of a conventional CD turntable device.

FIG. 6 is a cross-sectional view schematically illustrating the configuration of a conventional MD turntable device.

[Explanation of symbols]

 1 Spindle Motor 2 Output Shaft 3 Turntable 4 Clamper 5 CD 6 CD Inner Circumferential Part 7 Outer Circular Direct Wall Part 8 Inner Circular Direct Wall Part 9 Magnet 10 Clamper Direct Wall Part 11 Iron Plate 12 Clamper Outer Part 13 MD 14 Cartridge 15 Disc Board 16 MD inner peripheral portion 17 Magnetic material portion 21 Columnar portion 22 Through hole

Claims (10)

[Claims] 1. A turntable device comprising a turntable fixed to an output shaft of a rotation drive means and a clamper means capable of urging toward the turntable, wherein the turntable is an inner peripheral portion of a CD. Surface support means for contacting and supporting the lower surface of the MD, second surface support means for contacting and supporting the lower surface of the inner peripheral portion of the MD, and the inner peripheral wall surface of the inner peripheral portion of the MD or the inner peripheral surface thereof. A third surface supporting means for abutting and supporting the outer peripheral wall surface of the portion, and a magnet means for attracting and urging the magnetic material portion of the MD disk substrate, and the clamper means for the inner peripheral portion of the CD. An apparatus comprising: a fourth surface supporting means for contacting and supporting the inner peripheral wall surface; and an outer peripheral portion for pressing the upper surface of the inner peripheral portion of the CD when the CD is positioned and held. 2. The first surface supporting means is an upper end surface of an outer peripheral straight wall portion formed on an outer peripheral portion of the turntable, and the second surface supporting means is formed inside the outer peripheral straight wall portion. An annular surface supporting portion, the third surface supporting means is an outer peripheral wall surface of an inner peripheral straight wall portion or an inner peripheral wall surface of the outer peripheral straight wall portion formed inside the annular surface supporting portion, and the fourth surface supporting means Is an outer peripheral wall surface of a straight wall portion extending from the clamper means to the turntable side. 3. The apparatus according to claim 1, wherein a plate member made of a magnetic material is provided in a region of the clamper means facing the magnet means. 4. The CD according to claim 2, wherein the inner wall surface of the straight wall portion of the clamper abuts the outer wall surface of the inner straight wall portion of the turntable when the CD is positioned and held. apparatus. 5. A columnar protrusion extending toward the turntable is formed at a central portion of the clamper means, and the columnar protrusion of the clamper means is provided with a central through hole of the turntable when the CD is positioned and held. 4. The apparatus according to claim 2, wherein the apparatus enters into the inside, and the outer peripheral wall surface of the columnar projecting portion of the clamper means abuts the inner peripheral wall surface of the central through hole of the turntable. 6. A turntable device comprising a turntable fixed to an output shaft of a rotation driving means and a clamper means capable of urging toward the turntable, wherein the turntable is in a state of holding and positioning a CD. The first surface supporting means for contacting and supporting the lower surface of the inner peripheral portion of the CD, and for supporting and supporting the lower surface of the disc substrate of the MD in the positioning and holding state of the MD, and the inner peripheral surface of the inner peripheral portion of the MD. Second for abutting and supporting the wall surface or the outer peripheral wall surface of the inner peripheral portion
Surface support means and magnet means for attracting and urging the magnetic body portion of the MD disk substrate. The clamper means has a third surface for abutting and supporting the inner peripheral wall surface of the inner peripheral portion of the CD. An apparatus comprising: a support means; and an outer peripheral portion for pressing the upper surface of the inner peripheral portion of the CD when the CD is positioned and held. 7. The first surface supporting means is an upper end surface of an outer peripheral straight wall portion formed on the outer peripheral portion of the turntable, and the second surface supporting means is formed inside the annular surface supporting portion. It is an outer peripheral wall surface of an inner peripheral straight wall portion or an inner peripheral wall surface of the outer peripheral straight wall portion, and the third surface support means is an outer peripheral wall surface of a straight wall portion extending from the clamper means to the turntable side. The device according to claim 6. 8. The apparatus according to claim 6, wherein a plate member made of a magnetic material is provided in a region of the clamper means facing the magnet means. 9. The CD according to claim 7, wherein the inner wall surface of the straight wall portion of the clamper is in contact with the outer wall surface of the inner straight wall portion of the turntable when the CD is positioned and held. apparatus. 10. A columnar protrusion extending toward the turntable is formed at a central portion of the clamper means, and the columnar protrusion of the clamper means is provided with a central through hole of the turntable when the CD is positioned and held. 9. The apparatus according to claim 7, wherein the apparatus enters into the inside and the outer peripheral wall surface of the columnar protrusion of the clamper means abuts the inner peripheral wall surface of the central through hole of the turntable.