JP2981381B2 - Optical disk holding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk recording / reproducing apparatus, and more particularly to an optical disk holding apparatus for rotating an optical disk.

[0002]

2. Description of the Related Art A so-called mini disk (hereinafter referred to as MD) is known as a rewritable optical disk, and a recording / reproducing apparatus dedicated to the MD has been commercialized. Also, as a read-only optical disk, a compact disk (hereinafter referred to as CD) is used.
Is known, and a CD-only playback device or M
A compatible playback device for an optical disk other than D, such as a video disk or the like, and a CD has been commercialized.

[0003] CDs and MDs are common in that a light receiving element receives reflected light of a laser spot irradiated on a recording track from an optical pickup, and recording is reproduced as an output of the light receiving element.

However, CDs and MDs have the following differences. That is, in the MD, an optical disk is stored in a cartridge, and the optical disk in the cartridge is rotated and driven for recording and reproduction via a hole and a shutter formed in the cartridge, but the CD is not stored in the cartridge.

[0005] In the MD, a metal plate attached to a disk body is attracted by a magnet attached to the turntable to hold the disk on the turntable.
No metal plate is attached to D, and the disc is held on the turntable with the disc sandwiched from above and below.

Further, both CD and MD are provided with a positioning hole at the center thereof.
Larger than D, the hole in the CD is penetrating up and down,
The MD hole is closed on the upper side with a metal plate for suction.

As described above, since the CD and the MD have different disc shapes and structures of the holding portions, they are rotated and driven by a common disc motor, though they are common in that they are reproduced by reflected light of a laser spot. However, a compatible reproducing apparatus for reproducing by a common optical pickup has not been realized.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a compatible reproducing apparatus by holding a CD and an MD on a common turntable. An object of the present invention is to provide an optical disk holding device that can be realized.

[0009]

According to the present invention, there is provided an optical disk holding apparatus comprising: a fixed member fixed to a rotating shaft of a disk motor; and a movable member guided by the fixed member and arranged to move up and down within a predetermined range. And a clamper that is moved between a position where the fixed member or the movable member is brought into contact with the fixed member and a position that is separated upward from the fixed member or the movable member, and a holding member is provided on an upper surface of the fixed member. Holding means for holding the holding member of the first optical disk, and a first reference surface for determining the height position of the upper surface of the second optical disk on which the holding member is not provided is provided on the lower surface of the clamper. And a convex portion having a tapered portion at a distal end which fits into a center hole of the second optical disk to determine a position in a disk diametrical direction is formed at a central portion of a lower surface of the clamper. The movable member is the pressing surface for pressing the second optical disk in the clamper is formed around the upper surface, the biasing means and the second said peripheral top surface by
The second optical disc contacts a central flange surface of the first optical disc when the movable member is in contact with a lower limit stopper of the fixed member on the upper surface of the movable member to determine a height position. A reference surface is provided, and one of the fixed member and the movable member is provided with a surface for fitting and positioning the first optical disk with the center hole thereof, and holds the second optical disk. The difference between the height of the first reference surface and the height of the second reference surface when holding the first optical disc is the difference between the height of the upper press-contact surface of the second optical disc and the recording surface. And the height difference between the central flange surface of the first optical disk and the recording surface.

Further, in the optical disk holding device,
A coil spring disposed between the fixed member and the movable member for urging the movable member, or a suction member provided on the clamper for sucking the movable member, or both the coil spring and the suction member It is what it was.

Further, in each of the optical disk holding devices, one or both of the contact surfaces of the fixing member and the clamper are formed so as to have a large friction coefficient, or a member having a large friction coefficient is provided. Is what it is.

Further, in each of the optical disk holding devices, a pressure contact surface of the clamper which presses against an upper surface of the second optical disk is formed so as to have a large friction coefficient, or a member having a large friction coefficient is provided. It is.

Further, in each of the optical disk holding devices, one or both of the contact surfaces where the movable member and the fixed member contact each other when the movable member is at the lower limit position are formed so as to have a large friction coefficient. Or a member having a large coefficient of friction is provided.

Further, in each of the optical disk holding devices, a detent member is provided between the movable member and the fixed member.

Further, in each of the optical disk holding devices, at least a part of a fitting surface where the fixing member and the clamper fit is formed in a cylindrical surface.

[0016]

According to the optical disk holding device of the present invention, when an optical disk provided with a holding member which is a magnetic metal plate, that is, an MD, is loaded, the clamper is held above the fixing member, and The provided holding means, for example, a magnet attracts the metal plate of the MD, and the MD is pulled downward. The MD moves downward, and its central flange surface is pressed against the press-contact surface of the movable member at the lower limit position of the movable member to perform vertical positioning.

When the MD moves downward, the center hole of the MD fits with a positioning surface provided on either the fixed member or the movable member, and the MD is positioned coaxially with the rotation axis of the disk motor. . Rotation of the disk motor is transmitted to the MD by a frictional force between the fixed member and the movable member and a frictional force between the movable member and the MD central flange surface.

When an optical disk, ie, a CD, without a holding member is loaded, the clamper is moved toward the fixed member, and the holding means provided on the fixed member sucks the suctioned member of the clamper, or moves the clamper up and down. A mechanism presses the clamper against the fixing member via a spring.

At this time, the clamper and the fixed member or the movable member are fitted, and the horizontal position of the clamper is determined. If a part of the fitting surface is a cylindrical surface, displacement of the clamper when an external force is applied by vibration or the like is prevented.

Then, the movable member is urged upward by the urging means, and the CD is pushed upward by the movable member and fits into the convex portion of the clamper to determine the position in the diameter direction. Also,
The CD is pressed against the pressure contact surface of the clamper, and the rotation of the disk motor is transmitted to the CD by the friction force between the fixed member and the clamper and the friction force between the clamper pressure contact surface and the CD pressure surface.
The surface on which the frictional force acts is formed so as to have a large friction coefficient, or a member having a large friction coefficient is attached to the surface, whereby the rotation of the disk motor can be reliably transmitted to the optical disk. .

Further, a detent member may be provided between the movable member and the fixed member to transmit a rotational force from the fixed member to the movable member without relying on frictional force.

As described above, according to the optical disk holding apparatus of the present invention, both the CD and the MD can be positioned and held on the rotating shaft of the disk motor and can be driven to rotate. The difference in height between the pressure contact surface and the pressure contact surface of the movable member when the MD is held is the difference in height between the upper pressure contact surface of the CD and the recording surface and the height difference between the central flange surface of the MD and the recording surface. Because it is the sum with the difference, CD
And the recording surface of the MD are located at the same height, and the CD and MD can be reproduced without changing the height of the optical pickup.

[0023]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing an optical disk holding device according to a first embodiment of the present invention. Reference numeral 1 shown in the figure is a rotating shaft of a disk motor fixed to a chassis. The rotating shaft 1 is press-fitted into a hole of the lower fixing member 2, and the lower fixing member 2 is integrated with the rotating shaft 1.

A compression coil spring 6 is disposed around the lower fixed member 2, and the movable member 5 is loosely fitted to the lower fixed member 2 so as to be above it. In this state, the upper fixing member 3 is fastened to the lower fixing member 2 with the screw 4. The movable member 5 is movable between a position in contact with the lower surface 3c of the outer peripheral portion of the upper fixed member 3 and a position in contact with the press-contact surface 2a of the lower fixed member 2, usually as shown in FIG. Due to the elasticity of the compression coil spring 6, the upper fixed member 3 is pressed against the outer lower surface 3c.

The upper surface 5a and the lower surface 5b of the movable member 5 are formed on a surface perpendicular to the disk motor rotating shaft 1. A ring-shaped magnet 7 is embedded in the upper part of the upper fixing member 3, and a positioning hole 3d is provided in the center. The hole 3d has an upper tapered surface 3e and a lower cylindrical surface 3f. Further, the upper fixing member 3
Is formed with a tapered surface 3a in the upper peripheral portion thereof, and the upper surface 3b
Are formed on a plane perpendicular to the disk motor rotation shaft 1.

FIG. 3 shows an outer shape in which the lower fixed member 2, the movable member 5 and the upper fixed member 3 are assembled. In particular, FIG. 3A shows a state in which the movable member 5 is at the upper limit position. FIG. 3C shows a state where the movable member 5 is at the lower limit position.

The clamper comprises a clamper body 9 and a screw 1
1 and a disc positioning member 13 fastened to the clamper body 9 with screws 15. The position shown in FIG. The convex mechanism 8a is driven by a driving mechanism (not shown) between the position where the convex part 8a is fitted and positioned in the hole 3d of the upper fixing member 3.

The lower surface 8d of the suction portion 8 is formed so as to be in close contact with the upper surface 3b of the upper fixing member 3, and a convex portion 8a is provided at the center thereof. The convex portion 8a is formed with a cylindrical portion 8b at the root and a tapered portion 8c at the tip.
The cylindrical portion 8b is fitted to the cylindrical surface 3f of the hole of the upper fixing member 3 with a very small gap.

A ring-shaped magnet 11 for attracting the movable member 5 via a disk positioning member 13 is embedded on the lower surface of the clamper main body 9, and a friction member 16 for pressing the compact disk to transmit rotational force by pressing the movable member 5 outside. Is attached. The disc positioning member 13 is formed with a fitting portion 13b that smoothly fits into the hole of the compact disc and a tapered guide portion 13a that guides the compact disc to the fitting portion 13b. FIG. 2 shows the outer shape of the clamper.

FIGS. 4 and 5 show a compact disk (CD) held by the optical disk holding device. A center hole 12a for positioning is provided in the center of the compact disk 12.

FIGS. 6 and 7 show a mini-disc (MD) held by the above-mentioned optical disc holding device. The mini disk 14a is housed in the cartridge 14. The cartridge 14 is provided with a hole 14e for holding the mini-disk 14a in the holding device, a shutter for passing the laser beam from the optical pickup, and a shutter for pressing the magnetic head against the mini-disk 14a.

A center hole 14c for positioning in the radial direction and a flange portion 14d for positioning in the height direction are provided at the center of the mini disk 14a. Furthermore, metal plate 1
4b is embedded so as to cover the upper side of the center hole 14c.

Next, the manner in which a compact disk is held by the holding device will be described with reference to FIGS. First, the clamper body 9 is held at a position shown in FIG. 8 directly above the upper fixing member 3 by the clamper driving mechanism.

In this state, the compact disk 12 is transported above the upper fixing member 3 by the loading mechanism, and then the center hole 12a of the compact disk 12 is
It is lowered on the upper surface 5a of the movable member 5 so as to be substantially concentric. At this time, the elastic force of the compression coil spring 6 is
The movable member 5 is kept pressed against the upper fixed member 3 because the gravity is larger than the gravity of the compact disk 12.

Next, the clamper body 9 is lowered by the clamper driving mechanism. Then, as shown in FIG. 9, the attracting portion 8 is attracted to the magnet 7, the convex portion 8a is fitted into the hole 3d, and the clamper is positioned coaxially with the disk motor rotating shaft 1. Further, the cylindrical portion 8b of the convex portion 8a and the cylindrical surface 3 of the hole 3d are formed.
Since f fits, the inclination of the clamper is regulated.

The compact disk 12 placed on the upper surface 5a of the movable member 5 is pushed down by the clamper, but the movable member 5 is urged upward by the compression coil spring 6 and is attracted by the magnet 11, so that the compact disk is compact. The disc 12 is pushed upward, and the compact disc 12 is guided by the guide portion 13a of the disc positioning member 13, the center hole 12a is fitted with the fitting portion 13b, and further pressed against the friction member 16 of the clamper.

Thus, the compact disk 12
Is positioned coaxially and perpendicularly to the center axis of the disk motor rotating shaft 1, and the rotational force of the disk motor is the friction between the upper surface 3b of the upper fixing member 3 and the lower surface 8d of the suction portion 8, and the friction member 16 and the compact disk. The force is transmitted to the compact disk 12 via a frictional force with the pressing surface of the compact disc 12.

Next, a case where a mini disk is held by the holding device will be described with reference to FIGS. 10 and 11. FIG. In this case, the clamper main body 9 is not shown because it is held on the upper side by the clamper driving mechanism.

The cartridge 14 containing the mini-disc 14a is transported above the upper fixing member 3 by a loading mechanism as shown in FIG. 10, and then dropped onto the upper fixing member 3 as shown in FIG.

At this time, the metal plate 14 of the mini disc 14a is
b is attracted to the magnet 7. The center hole 14c of the mini-disc 14a is guided by the tapered surface 3a of the upper fixing member 3 so as to fit with the peripheral cylindrical portion. In this way,
The mini disc 14a is positioned coaxially with the disc motor rotating shaft 1.

The flange portion 1 of the mini disc 14a
4d depresses the movable member 5 to the lower limit against the elasticity of the compression coil spring 6, presses the lower surface 2a of the lower fixed member 2, the lower surface 5b of the movable member 5, the upper surface 5a of the movable member 5, and the flange portion of the mini disk 14a. 14d is in a pressure contact state, the position of the mini-disc 14a in the height direction is determined, and the surface of the mini-disc 14a is
Are positioned so as to be perpendicular to the central axis of

In this way, the mini disk is held,
The rotational force of the disc motor is the pressure contact surface 2a of the lower fixing member 2.
The force is transmitted to the mini-disc 14a via the frictional force between the movable member 5 and the lower surface 5b and the frictional force between the upper surface 5a of the movable member 5 and the flange portion 14d of the mini-disc.

The compact disk and the mini disk are held in the states shown in FIGS. 9 and 11, respectively. The height of the lower surface of the friction member 16 in the state of FIG. 9 and the height of the upper surface 5a of the movable member 5 in the state of FIG. Is equal to the sum of the difference between the height of the recording surface and the surface in contact with the friction member 16 of the compact disk and the difference of the height between the flange surface and the recording surface of the mini disk. Also, the height of both recording surfaces becomes the same while the mini-disc is held, and both discs can be reproduced without changing the height of the optical pickup.

FIG. 12 shows a modification of the above embodiment. In this example, a detent pin 17 is provided upright on the movable member 5, and the pin is engaged with a groove 2 b provided on the lower fixed member 2. With such a configuration, rotation can be reliably transmitted from the lower fixed member 2 to the movable member 5 irrespective of frictional force.

FIG. 13 shows another modification of the above embodiment.
In this example, a friction member 18 having a large friction coefficient is provided on the lower surface 5b of the movable member 5. With such a configuration, a larger rotational force can be transmitted from the lower fixed member 2 to the movable member 5. The friction member may be attached to the lower fixed member 2, and the friction coefficient may be increased by roughening either the contact surface of the lower fixed member 2 and the movable member 5 or both surfaces. Good.

FIG. 14 shows still another modification of the above embodiment. In this example, a friction member 19 having a large friction coefficient is attached to the lower surface 8d of the suction portion 8 of the clamper. With such a configuration, a larger rotational force can be transmitted from the upper fixing member 3 to the clamper. Note that the friction member may be attached to the upper fixing member 3, and the friction coefficient may be increased by roughening either the contact surface of the upper fixing member 3 and the suction portion 8 or both surfaces.

FIG. 15 shows still another modification of the above embodiment. In this example, the protrusion of the suction portion 8 of the clamper is formed only by the tapered portion 8e. With such a configuration, the clamper can be made thin, and usually only the tapered portion can perform sufficient positioning.

FIG. 16 is a sectional view showing an optical disk holding device according to a second embodiment of the present invention. In this embodiment, the convex cylindrical surface 5c provided on the movable member 5 fits with the concave cylindrical surface 13c of the disk positioning member 13 and the center hole 14c of the mini disk via a very small gap. The outer periphery of the upper fixing member 3 is considerably smaller than the center hole 14c of the mini disk. Other configurations are the same as those of the first embodiment.

FIG. 17 shows a state where the optical disk holding device holds a compact disk. The clamper is positioned by fitting the concave cylindrical surface 13c and the convex cylindrical surface 5c of the disc positioning member 13.

FIG. 18 shows the optical disk holding apparatus using M
FIG. 19 is a cross-sectional view showing a state where D is loaded above the holding device, and FIG. 19 is a cross-sectional view showing a state where the MD is lowered from the position shown in FIG. 18 and held by the holding device in the optical disk holding device. . In this embodiment, the convex cylindrical surface 5c of the movable member 5 and the center hole 14c of the mini-disc are used.
The positioning of the MD is performed by fitting with the above.

Although the embodiment is constructed as described above, the invention is not limited to this. For example, the attraction force of the magnet 11 may be increased and the compression coil spring 6 may be omitted. If the attraction force of the magnet 11 is equal to or greater than a predetermined value, the movable member 5 at the lower limit of the moving range is attracted together with the compact disk thereon, and the compact disk can be pressed against the friction member 16 attached to the clamper body 9.

When the compression coil spring 6 is omitted as described above, the lower surface 5b of the movable member 5 and the pressure contact surface 2a of the lower fixed member 2 are strongly pressed when the mini-disc is held, so that the movable member 5 The rotation is surely transmitted. Conversely, it is of course possible to increase the elasticity of the compression coil spring 6 and omit the magnet 11.

Further, the clamper body 9 can be urged by a spring or the like in a direction in which the clamper body 9 is pressed against the upper fixing member 3. In that case, the clamper main body 9 is stabilized against external force such as vibration. Such biasing of the clamper main body 9 can be performed by pressing a ball-shaped member provided at the upper center of the clamper main body 9 against an elastic member provided on the clamper elevating means.

Further, the attracting portion 8 attached to the clamper main body 9 may be arranged as a magnet with a polarity that attracts the magnet 7 of the upper fixing member 3 to each other. Further, the magnet may be integrated with the magnet 11 that attracts the movable member.

Further, the magnet 1 attached to the clamper body 9
1 and the disc positioning member 13 may be formed by an integral magnet.

Further, the disk positioning member 13 and the attracting portion 8 are formed as an integral member, and the polarity of the magnet closely attached to the disk positioning member 13 is set as the polarity for attracting the magnet 7 of the upper fixing member 3 to each other. Is also good.

Further, the clamper body 9 and the friction member 16 can be made of resin, and the attraction portion 8 and the magnet 11 can be made into an integral structure by insert molding.

[0058]

According to the optical disk holding apparatus of the present invention, the compact disk and the mini disk can be held on the same rotating shaft of the disk motor with the same recording surface height, so that the height of the optical pickup can be reduced. Both discs can be reproduced without changing, and a compatible reproducing apparatus with low manufacturing cost can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an optical disk holding device according to a first embodiment of the present invention.

FIG. 2A is a front view showing a clamper of the optical disk holding device, and FIG. 2B is a bottom view showing the clamper.

FIG. 3A is a front view showing a main body of the optical disk holding device, FIG. 3B is a plan view showing the main body,
FIG. 3C is a front view showing a state where the movable member of the main body portion is pushed down.

FIG. 4A is a plan view showing a CD held by the optical disk holding device, and FIG. 4B is a sectional view showing the CD.

FIG. 5 is an enlarged view of a central portion of a cross-sectional view showing the CD.

FIG. 6A is a plan view showing an MD held by the optical disk holding device, FIG. 4B is a back view showing the MD,
FIG. 4C is a side view showing the same MD, and FIG.
FIG.

FIG. 7 is an enlarged view of a central part of a sectional view showing the MD.

FIG. 8 is a cross-sectional view showing a state before a CD is loaded and a clamper descends in the optical disk holding device.

FIG. 9 is a cross-sectional view showing a state where the CD is loaded and the clamper is lowered to hold the CD in the optical disk holding device.

FIG. 10 is a cross-sectional view showing a state where the MD is loaded above the holding device in the optical disk holding device.

FIG. 11 shows an optical disk holding device in which the MD is shown in FIG.
FIG. 5 is a cross-sectional view illustrating a state where the display device is lowered from the position illustrated in FIG.

FIG. 12A is a cross-sectional view showing a state in which the movable member 5 is at an upper limit position in a modification of the optical disc holding device, and FIG. 12B is a sectional view showing the movable member 5 in a lower limit position in the modification. FIG. 12C is a cross-sectional view showing the state, and FIG. 12C is a bottom view showing the modification.

FIG. 13A is a cross-sectional view showing a state where the movable member 5 is at an upper limit position in another modification of the optical disk holding device, and FIG. 13B is a sectional view showing a state where the movable member 5 is at the lower limit position in the modification. FIG. 3 is a cross-sectional view showing the state of FIG.

FIG. 14A is a cross-sectional view showing a state in which a clamper main body 9 is located above an upper fixing member 3 in still another modified example of the optical disk holding device, and FIG. 14B is a sectional view showing the modified example. FIG. 5 is a cross-sectional view showing a state in which the suction portion 8 of the clamper is in close contact with the upper fixing member 3.

FIG. 15A is a cross-sectional view showing a state in which a clamper main body 9 is located above an upper fixing member 3 in still another modified example of the optical disk holding device, and FIG. FIG. 5 is a cross-sectional view showing a state in which the suction portion 8 of the clamper is in close contact with the upper fixing member 3.

FIG. 16 is a sectional view showing a state before a CD is loaded and a clamper descends in the optical disk holding device according to the second embodiment of the present invention.

FIG. 17 is a cross-sectional view showing a state where the CD is loaded and the clamper descends to hold the CD in the optical disk holding device.

FIG. 18 is a cross-sectional view showing a state where the MD is loaded up to above the holding device in the same optical disk holding device.

FIG. 19 shows an optical disc holding device in which the MD is shown in FIG.
FIG. 5 is a cross-sectional view illustrating a state where the display device is lowered from the position illustrated in FIG.

[Explanation of symbols]

DESCRIPTION OF REFERENCE NUMERALS 1 disk motor rotating shaft 2 lower fixing member, 2a pressure contact surface, 2b groove 3 upper fixing member, 3a taper surface, 3b upper surface, 3c
Lower surface of outer peripheral portion, 3d hole, 3e taper surface, 3f cylindrical surface 4 screw 5 movable member, 5a upper surface, 5b lower surface, 5c convex cylindrical surface 6 compression coil spring 7 magnet 8 suction portion, 8a convex portion, 8b cylindrical portion, 8c Tapered portion, 8d lower surface, 8e Tapered portion 9 Clamper body 10 Screw 11 Magnet 12 Compact disk, 12a Center hole 13 Disk positioning member, 13a Guide portion, 13
b fitting part, 13c concave cylindrical surface 14 cartridge, 14a mini disk, 14b
Metal plate, 14c center hole, 14d flange, 14e
Hole 15 Screw 16 Friction member 17 Lock pin 18 Friction member 19 Friction member

Claims (7)

(57) [Claims] A fixed member fixed to a rotating shaft of a disk motor; a movable member guided by the fixed member and arranged to move up and down within a predetermined range; and a movable member arranged in contact with the fixed member or the movable member. A holding member for holding a holding member of a first optical disc having a holding member provided on a top surface of the fixing member, the holding member being provided between a fitting position and a position upwardly separated from a fixed member or a movable member; Means is provided, a first reference surface for determining a height position of an upper surface of a second optical disk on which no holding member is provided is provided on a lower surface of the clamper, and a center portion of a lower surface of the clamper is further provided. A convex portion having a tapered portion is formed at the tip for determining the position in the radial direction of the disc by fitting with the center hole of the second optical disc, and the movable member is provided on the peripheral upper surface thereof with the second optical disc. A pressing surface for pressing the disc against the clamper is formed, the upper peripheral surface is pressed against the second optical disk by a biasing means, and the movable member contacts the lower limit stopper of the fixed member on the upper surface of the movable member. A second reference surface for determining a height position by contacting a central flange surface of the first optical disk when in contact with the first optical disk is provided, and the first optical disk is provided on one of the fixed member and the movable member. The first reference surface when holding the second optical disk and the second reference surface when holding the first optical disk are formed. The difference in height from the surface is the sum of the difference in height between the upper surface pressure contact surface of the second optical disk and the recording surface and the difference in height between the central flange surface of the first optical disk and the recording surface. Optical disk configured to be Lifting apparatus. 2. The biasing means of the movable member includes a coil spring disposed between the fixed member and the movable member, a suction member provided on the clamper for sucking the movable member, or the coil spring. 2. The optical disk holding device according to claim 1, wherein the optical disk holding device is both a suction member and a suction member. 3. The device according to claim 1, wherein one or both of the contact surfaces of the fixing member and the clamper are formed to have a large friction coefficient, or a member having a large friction coefficient is provided. Optical disk holding device. 4. The pressure contact surface of the clamper, which is in contact with the upper surface of the second optical disc, is formed to have a large friction coefficient, or a member having a large friction coefficient is provided. An optical disk holding device according to claim 1. 5. When the movable member is at the lower limit position, one or both of the contact surfaces where the movable member and the fixed member contact each other are formed so as to have a large coefficient of friction.
Or a member having a large friction coefficient is provided.
5. The optical disk holding device according to any one of items 1 to 4. 6. The optical disk holding device according to claim 1, wherein a rotation preventing member is provided between the movable member and the fixed member. 7. The optical disk holding device according to claim 1, wherein at least a part of a fitting surface where the fixing member and the clamper fit is formed in a cylindrical surface.