JPH09297951A - Chucking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a discoid recording medium from flawing and also to improve mechanical strength of a chucking plate. SOLUTION: The device is equipped with a turntable 11A to be mounted with a double-sided optical disk 2 and to be rotationally driven, a chucking member 20 for supporting an inner circumferential part 6 of the double-sided optical disk 2, the chucking plate 40 for supporting this chucking member 20 in the middle part and one pair of guide frames 50A and 50B for freely movably supporting both end parts of this chucking plate 40. The chucking plate 40 is provided with an inclined part 47 from the middle part over to both ends on a front surface wall 45 and a back surface wall 46 on the side opposite to the double-sided optical disk 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chucking device for attaching and detaching a disk-shaped recording medium such as an optical disk or a magneto-optical disk to a disk drive device.

[0002]

2. Description of the Related Art A conventional chucking device is used for double-sided optical discs having diameters of 200 mm and 300 mm. In this double-sided optical disk, two disk plates each formed in a disk shape having a central hole are stuck together. In these disc plates, the area where the information signal layer of this signal recording surface is formed is used as the information signal area. The disc plate has an inner peripheral portion provided on the center hole side and an outer peripheral portion as a non-information signal region.

A conventional chucking device includes a chucking member for supporting an inner peripheral portion of a double-sided optical disc between a turntable of an optical disc driving device, a chucking plate for supporting the chucking member in a central portion, and A pair of guide frames that support the chucking plate so as to be vertically movable.

The chucking member is arranged so as to face the disk table of the optical disk drive. The chucking member is a substantially circular shallow plate-shaped support substrate, and a substantially disk-shaped magnet supported below the support substrate,
A substantially disk-shaped pressing plate supported by a support substrate so as to be vertically movable.

The chucking plate is formed in a horizontally long rectangular shape. The chucking plate has a pair of guide pins protruding from one side surface. In addition, a guide member having a pair of guide pins protruding from the other side surface is attached to the chucking plate. The chucking plate is provided with a front wall and a back wall bent on the front surface and the back surface, respectively.

In this chucking device, the chucking plate is moved and operated in the direction of approaching the turntable of the optical disk drive device with the guide pins supported by the guide frame. In the chucking member, the magnet enters the center hole of the double-sided optical disk and is attracted to the metal plate of the turntable of the optical disk drive, and the pressing plate supports the inner peripheral portion of the double-sided optical disk. Then, in the chucking device, when the spindle motor of the optical disc drive device is rotationally driven, the chucking member rotates together with the turntable to rotate the double-sided optical disc at a constant linear velocity.

[0007]

By the way, since the above-mentioned double-sided optical disk is made of a soft synthetic resin material, it may warp. Further, since this double-sided optical disk has a diameter of 200 mm or 300 mm, when it is rotated while the center hole and the inner peripheral portion are supported, shake may occur.

Therefore, in the chucking device, the chucking plate comes into contact with the information signal area and the outer peripheral portion of the double-sided optical disk, and damages the double-sided optical disk. Therefore, the chucking device has a problem that it interferes with the reproduction of the information signal on the double-sided optical disk.

As a means for solving this problem, a chucking device in which the chucking plate is prevented from being deformed and coming into contact with the double-sided optical disk can be considered.

For example, as shown in FIG. 10, a chucking device of the magnet chuck type is a chucking plate 61.
At the midpoint C, a load W generated when the chucking member is separated from the metal plate of the turntable is vertically downward. Further, on the chucking plate 61, fulcrum reaction forces Ra and Rb generated by the guide frames 62A and 62B merely supporting the load W on the fulcrums A and B are generated vertically upward. The chucking plate 61 has a length dimension from the fulcrum A to the fulcrum B of 1
And the length dimension from each of the fulcrums A and B to the midpoint C is 1/2.

Therefore, the bending moment M ₁ at the position x between ACs is expressed by the following equation (1).

M ₁ = R _ax = Wx / 2 (0 ≦ x ≦ l / 2) (1) Further, the bending moment M ₂ at the position x between CBs is expressed by the following formula (2). To be done.

M ₂ = R _a x−W (x−l / 2) = W (l−x) / 2 (l / 2 <x ≦ l) (2) The bending moments M ₁ and M ₂ Is represented by a bending moment diagram as shown in FIG.
It becomes 1/4.

Further, for example, a mechanical chuck type chucking device is, as shown in FIG. 12, a chucking plate 63.
At the midpoint C, a load W is generated vertically upward when the chucking member is pressed by the elastic force of the compression coil spring during reproduction. In addition, the chucking plate 63 has both fulcrums A and B.
Guide frames 64A and 64B that only support the load W
The fulcrum reaction forces Ra and Rb are generated vertically downward. The length of the chucking plate 63 from the fulcrum A to the fulcrum B is l, and the length from the fulcrums A and B to the midpoint C is 1/2.

Therefore, the bending moment M ₁ at the position x between ACs is expressed by the following equation (3).

M ₁ = R _ax = Wx / 2 (0 ≦ x ≦ l / 2) (3) Further, the bending moment M ₂ at the position x between CB is expressed by the following formula (4). To be done.

M ₂ = R _ax −W (x−l / 2) = W (l−x) / 2 (l / 2 <x ≦ l) (4) The bending moments M ₁ and M ₂ Is represented by a bending moment diagram as shown in FIG. 13, and has a maximum of W1 / 4 when x = 1/2.

Therefore, in these chucking devices, the bending moments M ₁ of the chucking plates 61 and 63,
There is a problem in that the cross section having the maximum M ₂ becomes a dangerous cross section and a sufficient cross section modulus Z cannot be secured. Therefore, in the conventional chucking device, when the chucking plates 61 and 63 are deformed in order to avoid contact with the double-sided optical disk, they may be plastically deformed or damaged by a drop impact or the like. There was a problem such as.

Therefore, the present invention has been proposed for the purpose of providing a chucking device which prevents damage to a disk-shaped recording medium and improves the mechanical strength of a chucking plate. .

[0020]

The chucking device according to the present invention, which has achieved this object, has an inner peripheral portion of a disk-shaped recording medium between the disk and the turntable on which the disk-shaped recording medium is rotatably driven. A chucking member for supporting the chucking member, a chucking plate for supporting the chucking member at the central portion, and a pair of guide frames for movably supporting both end portions of the chucking plate. The chucking plate is provided on the side corresponding to the disc-shaped recording medium with an inclined portion whose thickness is gradually reduced from the central portion toward both ends.

In the chucking device according to the present invention having the above-described structure, the chucking plate is moved and operated in the direction approaching the turntable of the disk drive device. The chucking member supports the inner peripheral portion of the disk-shaped recording medium between the chucking member and the turntable. At this time, the chucking member is in a rotatable state with respect to the chucking plate.
The chucking member rotates together with the turntable of the optical disk drive to rotate the disk-shaped recording medium at a constant linear velocity. At this time, since the chucking plate is provided with the inclined portions on the front wall and the rear wall, the disc-shaped recording medium is rotated while avoiding contact with the disc-shaped recording medium.

Further, in this chucking device, a load W generated when the chucking member is separated from the turntable is generated vertically downward in the central portion, and a fulcrum reaction force by the guide frames for supporting the load W is provided at both end portions. If it occurs vertically upward and the maximum bending stress σ ₀ is constant over the entire length l,
The section modulus Z ₁ at the position x (0 ≦ x ≦ l / 2) between the one end and the center is: Z ₁ = Wx / 2σ ₀ The position x (l between the center and the other end The cross-sectional modulus Z ₂ at / 2 <x ≦ l) is a value represented by Z ₂ = W (l−x) / 2σ ₀ .

In the chucking device constructed as described above, the chucking plate is moved and operated in the direction in which it is separated from the turntable, with the chucking member being attracted to the turntable. At this time, the chucking board
A load W generated when the chucking member is separated from the turntable is vertically downward in the central portion, and a fulcrum reaction force by the guide frames for supporting the load W is vertically upward in both ends. At this time, the chucking member has equal strength because the front wall and the back wall are provided with the inclined portions so as to satisfy the conditions of the section coefficients Z ₁ and Z ₂ of the above equation.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below in detail with reference to the drawings of FIGS. The chucking device 1 shown as the embodiment of the present invention can also be used interchangeably with a disk-shaped recording medium such as a single-sided optical disk having a diameter of 80 mm and 120 mm and a double-sided optical disk 2 having a diameter of 200 mm and 300 mm. Type disk player device.

As shown in FIG. 1, a double-sided optical disc 2 having diameters of 200 mm and 300 mm has two disc plates 3A having a thickness of 0.6 mm and bonded to each other, as shown in FIG.
3B. These two disc plates 3A, 3B
Are each formed in a disk shape having a central hole 4. Further, these disc plates 3A and 3B have a base formed of a synthetic resin material, an information signal layer formed on the main surface of the base, and mechanical and chemical protection of the information signal layer. And a protective layer formed by coating on the information signal layer. In these disc plates 3A and 3B, the area where the information signal layer of this signal recording surface is formed is the information signal area 5. The disc plates 3A and 3B have a central hole 4
The inner peripheral portion 6 and the outer peripheral portion 7 provided on the side are used as the non-information signal area.

The disc player device, as shown in FIG. 1, is an optical disc drive device 1 for driving a double-sided optical disc 2.
0, and a chucking device 1 for attaching / detaching the double-sided optical disc 2 to / from the optical disc drive device 10.

As shown in FIG. 1, the optical disk drive device 10 includes a turntable 11A on which the inner peripheral portion 6 of the double-sided optical disk 2 is mounted, and a spindle motor 11B for rotating the turntable 11A. .

As shown in FIG. 1, the turntable 11A includes a spindle shaft 12 connected to an output shaft of a spindle motor 11B, a disk mounting member 13 fixed to the spindle shaft 12, and a disk mounting member. It has a disc support member 15 provided at the center of 13 and a metal plate 16 fixed to the disc mounting member 13 inside the disc support member 15. Further, as shown in FIG. 9, the turntable 12 has a compression coil spring 14 attached to the spindle shaft 12 inside the disk mounting member 13. When the spindle motor 11B is rotationally driven, the optical disk drive device 10 turns the turntable 1
1A rotates to rotate the double-sided optical disc 2 at a constant linear velocity.

As shown in FIG. 1, the disk mounting member 13 has an inner peripheral portion 6 of the double-sided optical disk 2 extending over the outer peripheral portion of the upper portion.
The mounting convex portion 17 that supports the projection is provided so as to project. The disk supporting member 15 is provided with a single-sided optical disk supporting portion 18 located near the spindle shaft 12 and supporting the center hole of the single-sided optical disk. Further, the disc supporting member 15 is provided with a double-sided optical disc supporting portion 19 located outside the single-sided optical disc supporting portion 18 for supporting the center hole 4 of the double-sided optical disc 2.

The metal plate 16 is formed in a substantially annular shape, and is provided between the single-sided optical disk supporting portion 18 and the double-sided optical disk supporting portion 19 of the disk supporting member 15.

As shown in FIG. 1, the chucking device 1 includes a chucking member 20 for supporting the inner peripheral portion 6 of the double-sided optical disc 2 between the chucking member 20 and the turntable 11A of the optical disc drive device 10, and the chucking member 20. And a chucking plate 40 for supporting the
A pair of guide frames 50 that supports 0 for vertical movement.
A and 50B are provided.

As shown in FIG. 1, the chucking member 20 is arranged so as to face the optical disk drive device 10. As shown in FIG. 2, the chucking member 20 includes a support plate 22 having a substantially circular shallow dish shape, and, as shown in FIG. 3, a magnet holder 23 having a substantially disk shape supported below the support substrate 22. The magnet holder 23 is provided with a substantially disc-shaped magnet 24 fixed to a lower portion thereof and a substantially disc-shaped pressing plate 25 supported by the magnet holder 23 so as to be vertically movable.

The support substrate 22 is made of a synthetic resin material. As shown in FIG. 4, the supporting substrate 22 is integrally formed with a supporting portion 26 that is supported by the chucking plate 40 over the outer peripheral portion of the upper portion. In addition, this support substrate 2
As shown in FIG. 5, the bearing 2 has a bearing portion 28, which is located at the center of the bottom surface and has a shaft hole 27 into which the spindle shaft 12 of the turntable 11A enters, and which projects downward. In addition, as shown in FIG. 4, the support substrate 22 is located around the shaft hole 27 on the bottom surface thereof, and the magnet holder 23
A substantially L-shaped support piece 29 for supporting the is integrally formed. Further, as shown in FIG. 5, the support substrate 22 is
An entrance opening 30 is provided on the bottom surface around the shaft hole 27, into which a part of the pressing plate 25 enters. Further, the support substrate 22 is located on the bottom surface around the shaft hole 27,
A through hole 31 into which a part of the pressing plate 25 enters is provided.

The magnet holder 23 is made of a metal material. As shown in FIG. 5, the magnet holder 23 has an outer diameter dimension substantially equal to the outer diameter dimension of the support portion 26 of the support substrate 22. The magnet holder 23 is provided at a central portion thereof with a bearing portion support hole 32 for allowing the bearing portion 28 of the support substrate 22 to enter and support the bearing portion 28. Also,
As shown in FIG. 4, the magnet holder 23 is provided with an inverted L-shaped support portion 33 that is located around the bearing portion support hole 32 and is supported by the support piece 29 of the support substrate 22. Further, in the magnet holder 23, as shown in FIG. 5, an engaging hole 34 into which a part of the pressing plate 25 enters the position corresponding to the entrance opening 30 of the support substrate 22 around the bearing supporting hole 32. Is provided. Further, the magnet holder 23 is provided with a guide groove 35 for guiding a part of the pressing plate 25 around the bearing support hole 32 at a position corresponding to the through hole 31 of the support substrate 22.

As shown in FIG. 5, the magnet 24 has an outer diameter dimension substantially equal to the outer diameter dimension of the metal plate 16 of the turntable 11A. The magnet 24 is located in the central portion, outside the bearing portion 28 of the support substrate 22,
A support portion entry hole 36 into which the single-sided optical disc support portion 18 provided on the disc support member 15 of the turntable 11A enters is provided. The magnet 24 is fixed to the lower part of the magnet holder 23 with an adhesive or the like.

The pressing plate 25 is made of a synthetic resin material. As shown in FIG. 5, the pressing plate 25 has an outer diameter dimension slightly smaller than the diameter dimension of the inner peripheral portion 6 of the double-sided optical disc 2. The pressing plate 25 is provided at a central portion thereof with a magnet entry hole 37 into which the magnet 24 is inserted. Further, the pressing plate 25 is provided around the magnet entry hole 37, and is provided with an engagement protrusion 38 that enters the engagement hole 34 of the magnet holder 23 and engages around the engagement hole 34. . Furthermore, the pressing plate 2
5 is integrally formed with a spring support pin 39 that enters the through hole 31 of the support substrate 22 and is guided by a guide groove 35 provided in the magnet holder 23. The compression coil spring 21 is attached to the spring support pin 39. The compression coil spring 21 is elastically displaced in a state where the pressing plate 25 is close to the magnet holder 23, and an elastic force in a direction for urging the pressing plate 25 downward is generated.
The pressing plate 25 projects the lower part of the magnet 24 from the magnet entry hole 37 while being close to the magnet holder 23.

The chucking plate 40 is formed in a horizontally long rectangular shape as shown in FIG. As shown in FIG. 6, the chucking plate 40 is provided with a support hole 41 for supporting the chucking member 20 in the central portion. The support portion 26 of the chucking member 20 is provided around the support hole 41.
Is supported. The chucking plate 40 has a pair of guide pins 42, 42 projecting from one side surface. A guide member 43 is attached to the other side surface of the chucking plate 40. This guide member 43 is
Guide pins 42, 42 of the chucking plate 40 on the other side
A pair of guide pins 44, 44 is provided at a position corresponding to. The chucking plate 40 is provided with a front wall 45 and a back wall 46 that are bent downward on the front surface and the back surface, respectively. These front wall 45 and back wall 46
As shown in FIG. 7, the side corresponding to the double-sided optical disk 2 is provided with inclined portions 47, 47 whose thickness dimension is gradually reduced from the central portion in the middle longitudinal direction toward both ends.

As shown in FIG. 1, the guide frame 50A is provided with a pair of guide grooves 51, 51 for inserting and supporting the guide pins 42, 42 of the chucking plate 40. These guide grooves 51, 51 are inclined grooves,
The chucking plate 40 is guided so as to be vertically movable with respect to the turntable 11A.

Further, as shown in FIG. 1, the guide frame 50B is provided with a pair of guide grooves 52, 52 for inserting and supporting the guide pins 44, 44 of the guide member 43 provided on the chucking plate 40. ing. These guide grooves 52, 52 are the guide grooves 5 of the guide frame 50A.
It is provided at a position facing 1 and 51 and is an inclined groove. These guide grooves 52, 52 are provided on the chucking plate 40.
Is guided so as to be vertically movable with respect to the turntable 11A.

Here, the chucking plate 40 includes the chucking member 20 as shown in FIG.
The load W generated when peeling from the metal plate 16 of A is the midpoint C
Occurs vertically downward. Also, the chucking plate 40 is
Guide frame 5 that only supports the load W on both fulcrums A and B
The fulcrum reaction forces Ra and Rb due to 0A and 50B are generated vertically upward. This chucking plate 40 is supported from the fulcrum A to the fulcrum B.
Is 1 and the length from each fulcrum A, B to the midpoint C is 1/2. The relationship between the load W and the fulcrum reaction forces Ra and Rb is expressed by the following formula (5) by the balance of the external force in the vertical direction.

R _a + R _b = W (Equation (5)) The relationship between the load W and the fulcrum reaction force Ra is expressed by the following equation (6) according to the balance of the bending moment due to the external force around the fulcrum B. It

R _a1 = Wl / 2 (Equation (6)) Therefore, Ra and Rb are represented by the following Equations (7) and (8) from Equations (5) and (6). .

R _a = W / 2 ... Equation (7) R _b = W / 2 ... Equation (8) Therefore, the bending moment M ₁ at the position x between ACs
Is represented by the following formula (9).

M ₁ = R _ax = Wx / 2 (0 ≦ x ≦ l / 2) (9) Further, the bending moment M ₂ at the position x between CB is expressed by the following formula (10). To be done.

M ₂ = R _a x−W (x−l / 2) = W (l−x) / 2 (l / 2 <x ≦ l) (10) The chucking plate 40 has a cross-section coefficient. Bending moment Z
When it is changed so as to be proportional to, the maximum bending stress σ ₀ generated on the surface becomes constant over the entire length.

The condition of the section modulus Z for the chucking plate 40 to have equal strength is expressed by the following equation (11).

Z = M / σ ₀ (Equation (11)) Therefore, the section modulus Z ₁ between AC is expressed by the above equation (9).
Therefore, the value is represented by the following formula (12).

Z ₁ = Wx / 2σ ₀ (0 ≦ x ≦ l / 2) (12) Further, the section modulus Z ₂ between CB is expressed by the following formula (13) from the above formula (10). It is supposed to be a value.

Z ₂ = W (l−x) / 2σ ₀ (l / 2 <x ≦ l) (13) Then, the chucking plate 40 is expressed by the above formulas (12) and (13). The front wall 45 and the rear wall 46 are provided with inclined portions 47, 47 so that the conditions of the section coefficients Z ₁ , Z ₂ are satisfied.
Are provided respectively.

In the chucking device 1 of the embodiment configured as described above, the double-sided optical disk 2 is the turntable 1.
The chucking plate 40 is moved while being placed on 1A. At this time, the inner peripheral portion 6 of the double-sided optical disk 2 is mounted on the mounting convex portion 17 of the disk mounting member 13 of the turntable 11A. Also, the double-sided optical disc 2 is
The center hole 4 is the disk support member 1 of the turntable 11A.
5 is supported by the double-sided disc support portion 19.

When the chucking plate 40 is moved, the guide pins 42 and 43 are guided by the guide frames 50A and 5A.
The moving direction is guided by the 0B guide grooves 51 and 52.
Therefore, the chucking plate 40 is attached to the turntable 11
It is moved and operated in the direction approaching A. As shown in FIG. 3, in the chucking member 20, the magnet 24 enters the center hole 4 of the double-sided optical disk 2 while the supporting portion 26 is supported by the chucking plate 40, and the pressing plate 2 is held.
5 contacts the inner peripheral portion 6 of the double-sided optical disk 2.

Then, as shown in FIG. 9, the magnet 24 of the chucking member 20 enters between the single-sided optical disc support portion 18 and the double-sided optical disc support portion 19 provided on the disc support member 15 of the turntable 11A. .
Then, the magnet 24 is attracted to the metal plate 16 of the turntable 11A.

At this time, in the chucking member 20, the bearing portion 28 provided on the support substrate 22 is provided on the turntable 11.
It enters the inside of the single-sided optical disk support portion 18 provided on the disk support member 15 of A. The bearing 28 is
The spindle shaft 12 of the turntable 11A is inserted into the shaft hole 27.

Then, the chucking plate 40 is further moved and operated in the direction approaching the turntable 11A. The pressing plate 25 of the chucking member 20 is pressed against the inner peripheral portion 6 of the double-sided optical disk 2. At this time, the compression coil spring 21 is elastically displaced and an elastic force is generated in the direction of urging the pressing plate 25 downward. The pressing plate 25 causes the turntable 11A to move by the elastic force of the compression coil spring 21.
The double-sided optical disk 2 is supported between the disk mounting member 13 and the mounting projection 17 provided on the disk mounting member 13.

At this time, in the chucking member 20, the support portion 26 of the support substrate 22 has the support hole 4 of the chucking plate 40.
Release from support by 1. Then, in the chucking member 20, as shown in FIG. 9, the upper portion of the support substrate 22 is projected from the support hole 41 of the chucking plate 40. At this time, the chucking member 20 is set to be rotatable with respect to the chucking plate 40.

The chucking member 20, when the spindle motor 11B of the optical disk drive 10 is driven to rotate,
It rotates together with the turntable 11A to rotate the double-sided optical disc 2 at a constant linear velocity. At this time, since the chucking plate 40 is provided with the inclined portions 47, 47 on the front wall 45 and the rear wall 46, as shown in FIG.
The double-sided optical disc 2 is rotated while avoiding contact with the information signal area 5 and the outer peripheral portion 7 of the double-sided optical disc 2.

The chucking device 1 includes a double-sided optical disc 2
The chucking plate 40 is operated to move when detaching from the turntable 11A. The chucking board 40 is
Guide pins 42 and 43 are guide frames 50A and 50B
The guide grooves 51 and 52 are guided in the moving direction, and the moving operation is performed in the direction away from the turntable 11A.

At this time, in the chucking member 20, the upper portion of the support substrate 22 enters the inside of the support hole 41 of the chucking plate 40. In the chucking member 20, the support portion 26 of the support substrate 22 has the support hole 4 of the chucking plate 40.
Supported around 1. And the chucking plate 40
In the state where the magnet 24 of the chucking member 20 is attracted to the metal plate 16 of the turntable 11A, is further moved and operated in the direction away from the turntable 11A. Then, in the chucking plate 40, a load W generated when the chucking member 20 is separated from the turntable 11A is vertically downwardly generated in the support hole 41 in the central portion, and the load W is applied to the guide pins 42 and 43 at both ends. The fulcrum reaction forces Ra and Rb generated by the supporting guide frames 50A and 50B are generated vertically upward. At this time, the chucking member 20
Is because the front wall 45 and the back wall 46 are provided with the inclined portions 47 and 47, respectively, so as to satisfy the sectional modulus Z ₁ and Z ₂ expressed by the conditions of the above formulas (12) and (13). , With equal strength.

The chucking device 1 of the above-described embodiment
Is provided with inclined portions 47, 47 whose thickness is gradually reduced from the central portion in the longitudinal direction of the front wall 45 and the rear wall 46 of the chucking member 40 toward both end portions thereof. The double-sided optical disc 2 is prevented from being damaged by the contact of the information signal area 5 and the outer peripheral portion 7 of the double-sided optical disc 2. Therefore, the chucking device 1 can cause the double-sided optical disc 2 to efficiently reproduce the information signal.

The chucking device 1 further includes the front wall 4 so that the chucking plate 40 satisfies the conditions of the section coefficients Z ₁ and Z ₂ expressed by the above equations (12) and (13).
5 and the back wall 46 are provided with the inclined portions 47, 47, respectively, and thus have equal strength and are prevented from being plastically deformed or damaged by a drop impact or the like. Therefore, the chucking device 1 is prevented from damaging the double-sided optical disc 2 and the chucking plate 40.
The mechanical strength of is improved.

Further, the chucking device 1 of the embodiment is
Double-sided optical disc with diameters of 200 mm and 300 mm 2
Besides, it can be used for a disc-shaped recording medium such as a single-sided optical disc having a diameter of 80 mm or 120 mm.

Further, although the chucking device 1 is provided inside the dual-purpose disc player device,
Single-sided optical disks with diameters of 80 mm and 120 mm, 2
It may be provided in each dedicated disc player device for reproducing a disc-shaped recording medium such as a 00 mm or 300 mm double-sided optical disc.

[0063]

In the chucking device according to the present invention, the chucking plate is provided on the side corresponding to the disk-shaped recording medium with the inclined portion whose thickness is gradually reduced from the central portion toward both ends. This prevents the chucking plate from coming into contact with and damaging the disc-shaped recording medium. Therefore, the chucking device can efficiently reproduce the information signal on the disc-shaped recording medium.

Further, the chucking device according to the present invention is
Since the front wall and the back wall are provided with inclined portions so as to satisfy the conditions of the section coefficients Z ₁ and Z ₂ of the chucking member, the chucking member has equal strength and is plastically deformable against a drop impact or the like. It is prevented from being damaged. Therefore, the chucking device can prevent the disk-shaped recording medium from being damaged and improve the mechanical strength of the chucking plate.

[Brief description of drawings]

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

FIG. 2 is a plan view showing a chucking member and a chucking plate that constitute the chucking device.

FIG. 3 is a partial cross-sectional view showing the chucking member and a chucking plate.

FIG. 4 is a plan view showing the chucking member.

FIG. 5 is a cross-sectional view showing the chucking member.

FIG. 6 is a plan view showing the chucking plate.

FIG. 7 is a front view showing the chucking plate.

FIG. 8 is a schematic diagram showing a chucking plate on which a load is applied by the chucking member.

FIG. 9 is a partial cross-sectional view showing a chucking device in which a double-sided optical disc is mounted on an optical disc driving device.

FIG. 10 is a schematic diagram showing a chucking member on which a load is applied by the chucking member in a conventional chucking device.

FIG. 11 is a moment diagram of the chucking member.

FIG. 12 is a schematic diagram showing a chucking member on which a load is applied by the chucking member in a conventional chucking device.

FIG. 13 is a moment diagram of the chucking member.

[Explanation of symbols]

1 chucking device, 2 double-sided optical disk, 11
A turntable, 20 chucking members, 40
Chucking board 45 Front wall, 46 Back wall, 4
7 Inclined part, 50A, 50B guide frame

Claims (2)

[Claims] 1. A chucking member that supports an inner peripheral portion of a disk-shaped recording medium between a turntable on which the disk-shaped recording medium is placed and is driven to rotate, and a chucking member that supports the chucking member at a central portion. The chucking plate is provided with a pair of guide frames that movably support both ends of the chucking plate. The chucking plate is provided on the side corresponding to the disk-shaped recording medium and has a thickness that increases from the center to both ends. A chucking device characterized in that an inclined portion having a gradually reduced size is provided. 2. The chucking plate has a load W generated when the chucking member is separated from the turntable at the central portion.
Is generated vertically downward, and a fulcrum reaction force by the guide frame for supporting the load W is vertically generated at both ends vertically upward. If the maximum bending stress σ ₀ is constant over the entire length l, between one end and the center. The cross-section coefficient Z ₁ at the position x (0 ≦ x ≦ l / 2) of Z ₁ = Wx / 2σ ₀ at the position x (1/2 <x ≦ l) between the central portion and the other end is The chucking device according to claim 1, wherein the section modulus Z ₂ is a value represented by Z ₂ = W (l−x) / 2σ ₀ , respectively.