JPH067473Y2 - Clamp structure of information recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention uses an information recording medium to record information on the medium or to read information recorded on the medium. The present invention relates to a clamp structure for accurately positioning and fixing the information recording medium in the information recording / reproducing apparatus.

[Outline of device]

According to the present invention, a guide member of the information recording medium having a cone-shaped portion is fixed to a spindle for driving the information recording medium, and a spring which is movable in the axial direction of the spindle near the guide member. When the information recording medium is clamped by the information recording / reproducing device, the guide member fixed to the spindle without play is used to adjust the eccentricity of the information recording medium. Horizontalness is secured at the hub.

[Conventional technology]

The conventional structure of the clamp structure in the information recording / reproducing apparatus will be described.

FIG. 5 is an assembled sectional view of a clamp portion showing a conventional structure. In the figure, 1 is a main frame, 2 is a spindle motor frame, 3 is a spindle motor rotor, 4 is a spindle fixed to the rotor 3, 5 is a bearing fixed to the spindle motor frame 2, and 6 is the above-mentioned. The spring means 8 is provided so as to be movable in the axial direction of the spindle 4.
A cone member that receives an upward biasing force from the disk, a hub 7 fixed to the spindle 4 and having a substantially horizontal disk mounting surface, and a cartridge 9 that holds a disk 13 that is an information recording medium. 12 is attached and detached,
It has an action of attaching and detaching the disk 13 to and from the clamp device composed of the cone member 6 and the hub 7.

A clamp plate 10 is provided with a magnet 11 inside and is supported by a clamp lever 20.

The operation will be described.

FIG. 5 shows a state before the disc 13 is mounted on the information recording / reproducing apparatus. As shown by an imaginary line, the disk 13 is inserted into the box portion of the holder 9 together with the cartridge 12 from the left opening. As is known, when the holder 9 is completely inserted, the holder 9 moves downward from the position 9a. Then, even if the disk 13 is slightly eccentric from the center of the spindle 4, the tip of the cone member 6 engages with the center hole of the disk during the downward movement, and the disk is centered along the slope of the disk. Slide in a direction to match the center of the spindle 4. When substantially the entire circumference of the central hole of the disk contacts the slope of the cone member 6, the cone member and the hole of the disk become substantially concentric. On the other hand, since the clamp lever 20 also moves downward almost simultaneously with the downward movement of the holder 9, the clamp plate 10 also moves downward, and the magnet 11 and the positioning pin 21 provided inside the clamp plate.
The clamp plate 10 further approaches the side of the hub 7 due to the suction action between them. At the time of this approach, it comes into contact with the surface of the disk in the above-mentioned state, and the disk 13 is pushed down together with the cone member 6 against the force of the spring 8 by the attraction force, so that the disk 1
The lower surface of 3 stands still while the entire circumference is in contact with the upper surface of the hub 7.

In this state, the entire circumference of the center hole of the disk 13 is guided by the slope of the cone member 6, and the hole of the disk is concentric with the cone member 6, and the periphery of the hole is The disk 7 is brought into contact with the disk mounting surface of the hub 7, the disk 13 is guided substantially horizontally by the hub 7, and the disk 13 is pressed by a clamp plate 10 from above the disk by a magnetic attraction force.

[Problems to be solved by the invention]

From the above, the known recording track of the disk 13 is completely concentric with the spindle 4 without being eccentric, and
There is no problem if it is attached vertically to the spindle 4 (the plane of the disk 13 is horizontal), but in the conventional structure, the cone member 6 can be moved vertically with respect to the spindle 4 as described above. Therefore, the dimension is set such that there is inevitably a play between the cone member 6 and the spindle 4. Because of the operation by the spring member 8 having a spring force weaker than the attraction force, the play becomes 5 to several tens of microns in view of processing capability and cost. As described above, the cone member 6 and the central hole of the disk 13 are Even if the eccentricity of the disk is close to 0, the disk 13 will be eccentric due to the backlash. The disk 13 has variations in eccentricity of the track with respect to the center hole, roundness of the track, and the like from the viewpoint of processing, and if this is also taken into consideration, the radial deviation of the track becomes large, and the track follows the track. There is a great influence on the follow-up performance of a well-known head (not shown) for reading / writing information by the information, and in the worst case, the head may not be able to follow the track. Further, naturally, the hole diameter of the disc and the cone portion diameter of the cone member 6 should not be loose even in the worst case. Therefore, as described above, the disc lower surface is placed on the hub 7, When it is completely clamped, the cone member 6 inevitably bends the spring 8 and descends downward so that the cone member 6 fits perfectly into the hole of the disc 13 and the disc 13 fits perfectly into the hub 7. Care has been taken to ensure that it is placed on the. Therefore, when the cartridge 12 and the disk 13 shown in FIG. 5 are taken out from the information recording / reproducing apparatus, the cone member 6 is completely raised until it comes into contact with the pin 21. When the cartridge 12 is attached to the information recording / reproducing apparatus again, it is necessary to pass above the cone member 6 so that the cartridge 12 does not interfere with the cone member 6, that is, the lower surface of the cartridge and the mounting surface of the hub. Between H
Height is required. Since H is one factor that determines the thickness T of the information recording / reproducing apparatus, a clamp structure in which H is as small as possible has been desired in developing a small information recording / reproducing apparatus.

In this way, the present invention reduces the eccentricity of the center hole of the disk 13 with respect to the spindle 4 when mounting the disk 13,
It is an object of the present invention to make it easy for the head to follow the track of the disk 13 and to provide a small and thin information recording / reproducing apparatus.

[Means for solving problems]

The clamp structure of the information recording / reproducing apparatus of the present invention is as follows: 1) An information recording medium, a spindle for driving the information recording medium, and a center of the information recording medium fixed to the shaft end of the spindle. A guide member for the information recording medium having a cone-shaped portion, a hub that is located near the guide member, has a mounting surface for the information recording medium, and is movable along the axis of the spindle, and to the hub. It is characterized in that it is constituted by engaging spring means.

2) When the information recording medium is not mounted on the information recording / reproducing apparatus, the hub is structured to be positioned by the guide member.

[Action]

In the present invention, as described above, the center hole of the disk 13 as the information recording medium is accurately set coaxially with the rotation center of the spindle 4, so that the cone member 6 is attached to the spindle 4.
Is fixed, the backlash between the two is eliminated, and the center hole and the cone member are surely fitted to each other even if the center hole of the disk 13 and the diameter of the cone member 6 vary.
The hub 7 is constructed so as to be movable in the axial direction of the spindle so that the disk can be guided horizontally to the hub, and the spring 8 is engaged with the hub 7.

By doing so, to the corner of the central hole of the disk 13, which plays an important role for the centering of the disk 13,
By cushioning the disc so that an excessive impact force is not applied when the disc is mounted, damage to the corner due to repeated mounting and removal can be prevented, and the reliability of alignment performance for long-term use can be improved.

〔Example〕

An embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is an assembled sectional view showing an embodiment of the present invention, showing a state before a disc is mounted on an information recording / reproducing apparatus.
2 is an assembled sectional view showing a state where the disk 13 is clamped by the clamp device, and FIG. 3 is an assembled plan view of FIG.
FIG. 4 shows the information recording / reproducing apparatus in the state shown in FIG.
3 is an operation explanatory view from the insertion of No. 3 to the complete clamping.

In all the drawings, 1 is a main frame and 2 is a spindle motor frame fixed to the main frame. Reference numeral 3 is a rotor of a spindle motor, 4 is a spindle fixed to the rotor, and 5 is a bearing fixed to a frame of the spindle motor, and the verticality of the spindle 4 is provided. Reference numeral 6 is a guide member for aligning the disk 13 fixed to the upper end of the spindle, which is a cone member having a cone-like portion, and 7 is located around the cone member and pushed upward by the force of a spring 8. The cone member 6
The hub is positioned in contact with the lower end of the spindle 4 and has a slight play with respect to the spindle 4 and is movable in the axial direction of the spindle 4. The lower end of the spring 8 is in contact with the inner ring of the bearing. Reference numeral 9 denotes a holder, which has a function of supporting a cartridge 12 that stores a disk 13 that is an information recording medium, and has a holding portion of the cartridge and four spring portions 9A, 9A, 9B, which extend from the holding portion. It has a portion 9B and further holds the clamp plate 10. Reference numeral 11 is a magnet provided inside the clamp plate 10. Thirteen
A is a hole provided substantially in the center of the disk 13.

With the above configuration, the operation will be described.

When the cartridge 12 is inserted into the information recording / reproducing apparatus in the power-off state in the state shown in FIG. 1 and when the cartridge 12 reaches the completely inserted position shown by the phantom line in FIG. 1, a known releasing member (not shown) is shown. 2), the lock is released, and the holder 9 descends from the upward position 9a to the lower position 9b shown in FIG. 2 by the spring force of the spring portions 9A, 9A, 9B, 9B. The operation is performed by the four leaf springs 9A, 9A of the holder,
9B, 9B and the spacer 14 for holding the leaf springs in parallel with each other.

When the holder 9 descends, the cartridge 12 also descends, and the disk 1 stored in the cartridge 12
3 also descends. The relationship between the disc 13 and the clamp device during the lowering operation will be described with reference to FIG.

When the disk 13 is at the initial position 13a and the holder 9 starts descending, the disk 13 also comes to the position 13b. During the lowering operation, the cartridge 12 and the disk 13 are also in an unstable state, and it is possible that they tilt like this. In the state of 13b, a part of the disk abuts on the upper surface of the raised position 7a of the hub 7. In this state, the disc is in an unstable state where it cannot be stopped, so the right side of the disc further descends, and the right side portion of the center hole 13A slides on the cone portion of the cone member 6 and is substantially aligned with the center of the spindle 4. Then, the lower surface of the disk is completely placed on the upper surface of the hub 7 and is held horizontally 13c. In the state thus far, the disc 13 is subjected to its own weight and acceleration at the time of lowering. Even if the cone portion of the cone member 6 is in the one-sided contact state as described above, the disk 13 is attached to the hub 7
When it comes into contact with the top, it is buffered by the momentary lowering operation of the hub 7 and the action of the spring 8, so that it does not receive a large impact force, so the corner of the center hole 13A of the disk is not damaged. The same applies to the contact portion between the hub 7 and the lower surface of the disk 13.

When the disc is stopped at the position of 13C, the clamp plate 10 held on the upper surface of the holder 9 moves to the disc 1
Abut on the upper surface of 3. Since the magnet 11 inside the clamp plate 10 is attracted to the cone member 6 made of a magnetic material, the attraction force pushes down the hub 7 from the position 7a to the position 7b against the force of the spring 8. The movement is performed substantially vertically because the boss portion of the hub 7 is set to be long and the play between the boss and the spindle 4 is set to a minimum, so that the horizontality of the disk 13 is improved. It will not be damaged. When the disk 13 descends, the center hole 13A of the disk 13 is guided by the cone member, and the descending operation of the disk stops when the entire circumference comes into contact with the cone member.
This position is 13d. In this state, the clamp plate 10
Is the pushing force of the disc by W ₁ , the generated force of the spring 8 by W
₂ , the contact force between the cone portion and the corner portion of the center hole 13A of the disc is W ₁ -W ₂ , (W ₁ > W ₂ ), so that the contact pressure is due to the corner and the contact pressure is small even if the area is small. Since it does not become so large, the center hole 13A is not damaged. In this state, the information recording / reproducing device is powered on.
And the spindle motor rotates, the spindle 4,
The disk 13 rotates via the hub 7. This state is shown in FIG. 2, in which a well-known head (not shown) accesses to read and write by accurately following the track on the disk.

[Effect of device]

Since the present invention is configured as described above, the play between the cone member 6 which is a guide member for aligning the center hole 13A of the disk 13 with the rotation axis of the spindle 4 and the spindle 4 can be made zero. The play between the cone member 6 and the spindle 4, which is seen in the conventional one, does not affect the eccentricity of the disk 13. Therefore, even if the spindle is rotated at a high speed, the known head can sufficiently follow the track on the disk 13 and can provide a high-performance device having a high transfer rate.

Further, as described above, in the process of clamping the disc, the disc first contacts the hub 7, the impact force is alleviated and buffered, and the corner of the center hole of the disc 13 contacts the cone portion. And the structure in which the cone member 6 and the disk 13 are completely fitted after the horizontality of the disk 13 is secured by the hub 7.
There is no twist when the cone member and the center hole 13A of the disc 13 are completely fitted, and no excessive force is applied to the corner of the center hole 13a of the disc 13, and the cone member 6 is attached to the spindle 4 as described above in the present invention. Since it is fixed as shown in FIG. 1, even if the lower surface of the cartridge is set so as not to interfere with the cone member 6 when the cartridge 12 is inserted, it is equivalent to the floating amount of the cone as compared with the conventional type. As a result, the amount H can be reduced, and therefore the thickness T of the information recording apparatus can be reduced, which is effective in reducing the thickness of the apparatus.

For further clamping force as described above is applied to the corner of the center hole 13A of the disc 13 be W _1, W ₂ force becomes small as W ₁ -W _2, the portion is damaged even disk 13 is repeatedly attached and detached However, there is no problem with the clamp.

As described above, the present invention has a structure in which the cone member is fixed to the spindle 4 to prevent the looseness between the two members from acting on the eccentricity of the disk 13. However, in the case of an optical information recording apparatus as an example, in general, The allowable eccentricity of the disk 13 with respect to the spindle 4 is about 50 μ, and the allowable deviation between the head and the tracks on the disk is required to have an accuracy within 0.1 μ. On the other hand, the levelness of the disk is allowed about ± 300, and the allowable defocus amount between the laser beam and the recording layer at that time is about 0.5 μ. Therefore, according to the present invention, the eccentricity, which requires more strict accuracy, is increased in safety and the hub 7 is made movable, so that the horizontality of the hub is slightly impaired, but the horizontality has a large allowable range. Therefore, a slight margin of error is allowed, and overall reliability can be improved together with the above-mentioned various effects.

In one embodiment of the present invention, the disk 13 is not provided with a metal piece for clamping, a clamp plate 10 is provided on the upper part of the holder 9, a magnet 11 is provided inside the clamp plate 10, and a magnet 11 is provided. The disk 13 is clamped by the attraction force with the cone member 6, but the method is not limited to this, and the attracted member may be the hub 7 or the spindle 4 and may be provided in the vicinity of these elements. It is also possible to use a certain magnetic material, or the clamp plate 10 is not used, and the cone member 6, the hub 7, etc. are composed of magnets, or a magnet is provided in the vicinity thereof, and the magnet is provided in the vicinity of the central hole 13A of the disk 13. It is also possible to fix a metal piece, adsorb the metal piece with the magnet, and clamp it.

In the conventional system, the cone member 6 is the spindle 4
The pin 21 is provided above the cone member 6 so as not to fall off from the cone member 6. However, in the present invention, since the cone member 6 is fixed to the upper end of the spindle, the pin can be abolished, and the cone member 6 can eliminate the hub 7. Can be prevented from falling off, which contributes to cost reduction due to improvement of parts processing and assembly. Further, the clamp structure can be applied to both a magnetic recording type and an optical recording type.

[Brief description of drawings]

FIG. 1 is an assembled sectional view showing an embodiment of the present invention. FIG. 2 is an assembled sectional view showing a state where the disk 13 is clamped by the clamp device in the embodiment of the present invention. FIG. 3 is an assembly plan view of FIG. FIG. 4 shows the information recording / reproducing apparatus in the state shown in FIG.
3 is an explanatory diagram of the operation from when 3 is inserted until it is completely clamped. FIG. FIG. 5 is an assembled sectional view showing a conventional structure. In all drawings, 1 ... Main frame 2 ... Spindle motor frame 3 ... Spindle motor rotor 4 ... Spindle 5 ... Bearing 6 ... Cone member 7 ... Hub 12 ... Cartridge 13 ... Disc

Claims (2)

[Scope of utility model registration request] 1. An information recording medium having an information recording medium, a spindle for driving the information recording medium, and a cone-shaped portion fixed to the shaft end of the spindle and centering the information recording medium. Guide member, a hub that is located near the guide member, has a mounting surface for the information recording medium, and is movable along the axis of the spindle, and spring means that engages with the hub. A clamp structure for an information recording / reproducing apparatus characterized in that 2. The utility model registration claim 1 wherein the hub is structured to be positioned by the guide member when the information recording / reproducing apparatus is not loaded with the information recording medium. Clamp structure of the described information recording / reproducing apparatus.