JPH02201765A - Disk clamping device - Google Patents

Abstract

PURPOSE:To attain centering for either surface of a disk even when centering dislocation exists by providing upper side and lower side centering hubs which can elastically vertically move, and a depressing mechanism, which depresses the upper side centering hub. CONSTITUTION:A lower side centering hub 5, which is attached to the center of a spindle cup 2 and can elastically vertically move, and an upper side centering hub 6, which is attached to the center of a clamper 4 and can elastically and vertically move, are provided. When the lower side disk of the double face reproducing disk is reproduced, the center hole of the lower side disk is fitted to the lower side centering hub 5 and clamps them, and when the upper side disk is reproduced, the upper side centering hub 6 is descended, the lower side centering hub 5 is depressed, and simultaneously the center hole of the upper side disk is fitted to the upper side centering hub 6. Thus even when the centering dislocation is generated to the double face reproducing disk, the centering can be surely executed for either surface.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a disc clamping device in a disk device such as an optical disc device, and particularly relates to a disc clamping device suitable for use with double-sided playback discs. .

[Prior Art] In a conventional disk clamp device, for example, a spindle cup for mounting a disk on the shaft of a spindle motor is fixed, and a clamper arm that moves up and down above the spindle cup holds the disk between it and the spindle cup. The clamper is supported, and a centering hub that is fitted into the center hole of the disk is provided in the center of the spindle cup so as to be elastically movable up and down. That is, it is a structure that only has a centering hub for centering the disc on the spindle cup side, and does not take single-sided playback into consideration.

In addition, there are two types of clampers: a spring type that uses a spring to apply a clamping force, and a magnetic type that has a permanent magnet that applies a clamping force using magnetic attraction force. Since the clamper arm can be kept in a non-contact state, the vibrations of the spindle motor are not transmitted to the entire device, which is said to be advantageous for video and audio.

[Problems to be Solved by the Invention] In recent years, double-sided playback discs in which two discs, an upper disc and a lower disc are bonded together, have been provided as optical video discs. This disc clamping device is not designed for double-sided playback, and has a structure in which the centering of the disc is performed only by the centering hub provided on the spindle cup side. Even when clamping, only the centering of the lower disc is always possible. Therefore, if there is misalignment between the bonded upper and lower disks, the upper disk cannot be centered. For this reason, in the case of an optical disk device capable of double-sided playback that has optical heads above and below the disk, a problem arises when playing back the upper disk.

The present invention has been made in order to solve the above problem, and even if a double-sided playback disc made by bonding two discs is misaligned, it is possible to reliably center it on either side. The purpose of the present invention is to provide a disc clamping device that can perform the following functions.

[Means for Solving the Problems] The present invention, which solves the above problems, provides a disk clamping device that clamps a disk using a spindle cup fixed to the shaft of a spindle motor and a clamper supported by a vertically movable clamper arm. a lower centering hub that is attached to the center of the spindle cup and is elastically movable up and down, and an upper centering hub that is attached to the center of the clamper so that it can be elastically moved up and down and that pushes down the lower centering hub when lowering. This disk clamp device is characterized by comprising a centering hub and a push-down mechanism that pushes down the upper centering hub.

According to a second aspect of the present invention, the push-down mechanism includes an electromagnet attached to the clamper arm, and a permanent magnet fixed to the upper centering hub opposite to the electromagnet.

[Function] In the disc clamp device configured as described above, when playing the lower disc of a double-sided playback disc, place the double-sided playback disc on the spindle cup, and fit the center hole of the lower disc into the lower centering hub. By clamping the double-sided reproduction disc in this state, it is possible to center the lower disc.

On the other hand, when playing the upper disc, lower the upper centering hub, use the lower centering hub to push down the lower centering hub, and at the same time fit the upper centering hub into the center hole of the upper disc. , it is possible to center the upper disk.

Moreover, in the disk clamp device of claim 2, "
When playing the second disc, the upper centering hub is pushed down by the repulsive force between the electromagnet and the permanent magnet.

[Example] Hereinafter, an example of the disc clamping device of the present invention will be described with reference to the drawings.

In this disk clamp device, 1 is the spindle motor shaft, 2 is the spindle cup, 3 is the clamper arm, 4 is the clamper, 5 is the lower centering hub, 6 is the upper centering hub, and 7 is the push-down The mechanism is shown.

The spindle cup 2 is formed of a magnetic material into a bottomed cylindrical shape with an open upper part, and
An outward flange 8 is formed at its upper end, and the vertical shaft 1 is fixed to the bottom wall thereof so as to pass therethrough and protrudes above the flange 8. A step portion 9 is formed at the middle portion in the vertical direction, and elongated guide grooves 11 are formed along the vertical direction at intervals of 1806 in the side wall of the small diameter portion 10 at the bottom.

The clamper arm \3 can be moved up and down by a 1 m drive mechanism (not shown). Further, a hole 12 is formed in the center of the clamper arm 3 into which a cylindrical portion of a clamper 4, etc., which will be described later, is inserted.

In the clamper 4, a flanged cup 14 formed by slightly drawing a ring plate is fixed to the lower end of a cylindrical part 13 inserted into a hole 12 of the clamper arm 3, and this flange (=I A link-shaped permanent magnet 15 is fixed to the inner side of the spindle cup 14, and this permanent magnet 15 faces the upper surface of the flange 8 of the spindle cup 2.

The lower centering hub 5 is fitted to the vertical shaft 1 of the spindle motor projecting into the spindle cup 2 so as to be movable up and down, and has an upper end fitted into a center hole of a small diameter disk. A centering part 16 for a small-diameter disc, and a centering part 17 for a large-diameter disc, which is fitted into the center hole of a large-diameter disc, are formed in two stages.
A straight portion 18 having a smaller diameter than the centering portion 17 for a large-diameter disk is formed. In this case, both centering parts 16 and 1
7 is formed in a tapered shape and is a centering portion 16 for small diameter discs.
One ring-shaped four part is formed so as to be cut out around the vertical axis 1. Then, the straight part 1
8 is fitted into the small diameter portion 10 of the spindle cup 2, and a stopper 20 that is engaged with the guide groove 11 of the small diameter portion 10 is integrally fixed to the lower end thereof. Further, between the lower surface of the large-diameter disk centering portion 17 of the lower centering hub 5 and the upper surface of the stepped portion 9 of the spindle cup 2, there is a coil spring or the like that biases the lower centering hub 5 upward. An elastic member 21 is provided.

On the other hand, the upper centering hub 6 is fitted into the inner side of the cylindrical portion 13 of the clamper 4 with an annular shape facing the lower centering hub 5, and is movable up and down.
A tapered large-diameter disk centering part 23 to be disposed in the flanged cup 14 of the clamper 4 is integrally provided at the lower end of the straight part 22 that is fitted into the clamper 4 . A permanent magnet 24 formed in the shape of a disk and having a larger diameter than the cylindrical portion 13 is fixed to the cylindrical portion 13 .

Since the length of the straight part 22 is longer than the cylindrical part 13 of the clamper 4, it can move up and down within the range of the straight part 22, and the permanent magnet 24 and the centering part 23 A coil is provided between the permanent magnet 24 and the outer surface of the flanged cup 14 of the clamper 4 to bias the upper centering hub 6 upwardly relative to the clamper 4. An elastic member 25 such as a spring is provided. The centering portion 23 also has a hole 26 into which the vertical shaft 1, which protrudes from the lower centering hub 5 when the upper and lower centering hubs 6 and 5 are butted against each other, is inserted, and Ring-shaped recess 19 of hub 5
A protruding ring 27 is formed to be inserted into. In this case, the length of the protruding ring 27 is the same as that of both centering hubs 5.
・Assuming that a double-sided playback disc is placed between 6,
When the protruding ring 27 is inserted into one of the four ring-shaped parts of the lower centering hub 5, the double-sided playback disc contacts only one of the large-diameter disc centering parts 17 and 23 of both centering hubs 5 and 6. The centering portions 17 and 23 are set to be spaced from each other to the extent possible.

The clamper arm 3, the clamper 4, and the upper centering hub 6 are connected to the upper centering hub 6.
A permanent magnet 24 integrated with the clamper arm 3 is disposed above the clamper arm 3 and placed on the clamper arm 3, so that the upper centering hub 6 is suspended from the clamper arm 3, and the upper centering hub 6 is suspended from the clamper arm 3. A flanged cup 14 is placed on the back surface of the centering portion 23 of the upper centering hub 5, and is indirectly supported by the clamper arm 3 via the upper centering hub 5. .

The push-down mechanism 7 includes the permanent magnet 24 of the upper centering hub 6, two electromagnets that apply a repulsive force to the permanent magnet 24, a DC power supply 30 that energizes the two electromagnets, and a switch 31 thereof. A cup-shaped magnetic holder 32 is attached to the upper surface of the clamper arm 3 in a downward posture, and the electromagnet 2 is mounted on the inner surface of the magnet holder 32 so as to face the permanent magnet 24 of the upper center link hub 5. is set up.

When the disk clamp device constructed in this manner is not in operation, the clamper arm 3 is in a standby position at an upper position and both centering hubs 5 and 6 are separated from each other, as shown in FIG. When playing the lower disk B of the double-sided playback disk (in this case 6 large-diameter disk) A,
Place the double-sided playback disk A on the upper surface of the flange 8 of the spindle cup 2, fit the center hole B of the lower disk B into the large-diameter disk centering portion 17 of the lower center link 85, and then remove the clamper arm 3. By lowering the clamper 4, the permanent magnet 15 of the clamper 4 is attracted to the spindle cup 2, and the double-sided reproduction disk A is sandwiched between them as shown in FIG. At this moment,
The upper centering hub 6 is supported with a protruding ring 27 inserted into each of the four ring-shaped parts of the lower centering hub 5, and is pulled upward by the elastic member 25, so that it can be used for double-sided regeneration. It is held apart from the surface of disk A. A lower reproducing head (path shown) is disposed below the lower disk B centered by the lower centering hub 5.
Only the information is read out.

On the other hand, when playing the upper disk C, the clamper arm 3 is further lowered from the state shown in FIG. Integrated permanent magnet 2
A repulsive force is applied to the upper centering hub 6 as shown by the arrow in FIG. Then, the centering portion 17 of the lower centering hub 5 is removed from the center hole B of the lower disk B, and its centering portion 23 is fitted into the center hole C0 of the upper disk C. At this time, even if there is misalignment between the upper disk C and the lower disk B, the lower centering huff 5 is removed from the lower disk B.
It is possible to center the upper disk C by guiding it along the tapered surface of the centering part 23 of the two-side centering hub 6 and then sliding it between the clamper 4 and the spindle cup 2. Then, information is only read out by an upper reproducing head (path shown in the figure) disposed above the upper disk C.

[Effects of the Invention] As explained above, according to the present invention, the lower centering hub is attached to the center of the spindle cup and is elastically movable up and down, and the lower centering hub is attached to the center of the clamper so that it can be elastically moved up and down. At the same time, the structure includes an upper centering hub that pushes down the lower centering hub when descending, and a push-down mechanism that pushes down the upper centering hub, so the upper disk and lower disk can be stuck together. When clamping a double-sided disc for playback, even if there is misalignment between the upper and lower discs, it is now possible to correctly center either side of the disc.

By constructing the push-down mechanism with an electromagnet attached to the clamper arm and a permanent magnet fixed to the upper centering hub opposite to this electromagnet, the vibration of the spindle motor is not transmitted to the entire device, and the image is A disk clamping device for double-sided playback disks based on the Macscrew 1 method, which has the characteristic of being advantageous for audio, has been skillfully realized.

[Brief explanation of the drawing]

The drawings show an embodiment of the disk clamping device of the present invention, and FIG. 1 is a longitudinal cross-sectional view in the non-operating state, and FIG. 2 is a state in which the lower disk is centered by the lower centering hub. FIG. 3 is a longitudinal sectional view showing a state in which the upper disk is centered by the upper centering hub. 1... shaft, 2... spindle cup,
3... Clamper arm, 4... Clamper, 5... Lower centering hub, 6...
・Upper centering hub, 7...pushing down mechanism,
15...Permanent magnet, 21...Elastic member, 24...Permanent magnet, 25...Elastic member, two...Electromagnets, A ...Double-sided playback disc, B...Lower disc, C...
・Upper disk, B1-Cl... Center hole.

Claims (1)

[Claims] 1. In a disk clamp device that clamps a disk using a spindle cup fixed to the shaft of a spindle motor and a clamper supported by a clamper arm that is movable up and down, a lower centering hub that is elastically movable up and down, an upper centering hub that is attached to the center of the clamper so that it can be elastically moved up and down and that presses down the lower centering hub when descending; A disc clamp device characterized by comprising a push-down mechanism for pushing down. 2. The disk clamp device according to claim 1, wherein the push-down mechanism includes an electromagnet attached to the clamper arm and a permanent magnet fixed to the upper centering hub opposite to the electromagnet. .