JPS6312425Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a turntable device for driving disk rotation, which is most suitable for application to, for example, a video disk player. This invention relates to a turntable device configured to attract and fix a disk by the suction force of a magnet provided on the turntable.

[Background technology and its problems]

FIG. 1 shows a conventional example of a turntable device for a video disc player. First, an annular recess 3 with an open upper end is provided on the outer periphery of a center pin 2 of a turntable 1.
An annular yoke 4 and a magnet 5 are mounted in the recess 3 one above the other, and are covered and fixed with a protective cover 6 made of a non-magnetic material. Next, an annular rubber 8 is fixed on the upper end surface 7 of the peripheral portion of the turntable 1, and the upper end surface of the rubber 8 is formed as a disk mounting surface 9.

Next, regarding mounting of the disk 11, the center hole 12 is fitted to the outer periphery of the cylindrical portion 13 for center positioning provided on the outer periphery of the recess 3 of the turntable 1, and the disk 11 is attached to the rubber 8. The disc is placed horizontally on the disc mounting surface 9 of the disc. Next, after installing this disk 11, the disk clamper 1
An adsorption iron core 15 provided at the center of the magnet 4 is inserted into the center pin 2 through its center hole 16, and placed on the magnet 5 (actually, a protective cover 6 is interposed therebetween). ]. The suction force of the adsorption iron core 15 by the magnet 5 is transmitted to the disk clamper 14 via the compression spring 16, and the disk 11 is transferred to the disk clamper 14 by an annular rubber 17 fixed to the lower surface of the peripheral portion of the disk clamper 14. is pressed onto the disk mounting surface 9 to fix it.
Note that the turntable 1 has a drive shaft 18 such as a motor shaft.
Rotationally driven by.

However, in the conventional example of such a structure,
A structure in which the upper end surface of the rubber 8 fixed to the turntable 1 is formed as a disk mounting surface 9, and the disk 11 is placed on the rubber 8 [In this conventional example, there is no upper and lower rubber 8, 17. , the disk 11 is easily damaged, and the upper and lower rubbers 8 and 17 are essential parts. ], it is difficult to accurately determine the mounting height (vertical position) of the disc 11 mounted on the turntable 1. That is, the mounting height of the disk 11 tends to change due to changes in the hardness of the rubber 8 due to aging and wear of the rubber 8. If the height of the disk 11 is incorrect, the distance between the pickup and the disk will be incorrect, and if the levelness of the disk 11 is incorrect, problems such as skew will occur, which will have a significant negative impact on the recording and reproducing characteristics. affect Furthermore, in this conventional example, the suction force of the adsorption iron core 15 adsorbed onto the magnet 5 is applied to the disc clamper 1 through the compression spring 16.
4, the suction force of the magnet 5 must be extremely large in order to obtain a sufficient force for pressing and fixing the disk 11 by the disk clamper 14. For this reason, the iron core for suction is always
5 will be strongly and shockingly adsorbed onto the magnet 5, and although the magnet 5 is covered with a protective cover 6, the magnet 5 is likely to be accidentally damaged due to the impact of the adsorption. Ta.

[Purpose of invention]

The present invention aims to provide a turntable device that can correct the above-mentioned defects.

[Summary of the idea]

In the present invention, a recess with an open upper end is provided in the turntable, a magnet with a yoke attached to the lower end surface is mounted in the recess, a disk is placed on the turntable, and the magnet is inserted into the recess. In a turntable device configured to be attracted onto the turntable by suction force, the upper end surface of the turntable forms a disk mounting surface, and the magnet is placed together with the yoke within a certain range in the vertical direction within the recess. A spacer is fixed to the upper end surface of the magnet, and a biasing means is used to move and bias the magnet upward together with the yoke to move the spacer above the disk mounting surface of the turntable. The disk is energized to protrude, and the disk with a yoke provided on the lower surface of the center is placed on the disk mounting surface of the turntable and attracted by the suction force of the magnet, and at this time, the disk is attached to the lower surface of the turntable. The turntable device is characterized in that the yoke presses the magnet downward through the spacer so that the magnet sinks downward against the urging means.

According to the present invention constructed in this manner, it is possible to obtain a turntable device in which the mounting height of the disk mounted on the turntable can be defined with high precision, and the magnet can be sufficiently protected.

〔Example〕

An embodiment in which the present invention is applied to a turntable device in a video disc player will be described below with reference to the drawings.

First, this video disk player is configured to be able to perform recording and playback using a disk capable of both recording and playback, such as a magneto-optical disk. Magneto-optical disks (hereinafter simply referred to as disks) are used while being stored in cartridges.

First, the disk cartridge will be explained with reference to FIGS. 4A and 4B.

The cartridge 21 is composed of upper and lower halves 22 and 23 molded from synthetic resin, and the disk 24 is housed horizontally within the cartridge 21. In the center of the disk 24 is a disk holder 25 made of aluminum or the like.
A yoke 26 having an annular shape is fixed to the lower surface 25a of the disk holder 25 with a plurality of machine screws 27. The disk holder 25 is loosely fitted into a holder fitting hole 28 provided at the center of the lower half 23 by means of a yoke 26. In addition, a center pin 29 is provided integrally at the center of the disk holder 28.
Thrust receiver 3 having a cap shape at the upper end 29a of
0 is fitted, and this thrust receiver 30 is pressed downward by a compression spring 31. Note that these thrust receivers 30 and compression springs 31 are attached to the upper half 2.
It is housed in a cylindrical portion 32 that is integrally provided at the center of the two. Further, on the lower surface 25a of the disk holder 25, a central recess 33 in the shape of a truncated cone is provided on the outer periphery of the lower end 29b of the center pin 29.

Therefore, according to this disk cartridge,
As shown in FIG. 4A, when not in use, the compression spring 31
The disk holder 25 is pressed onto the lower half 23 by the disk holder 25, and when the disk holder 25 is not in use, the disk 24 may rattle up and down or rotate freely within the cartridge 21 due to vibration etc. is prevented from being damaged.

Next, the turntable device will be explained with reference to FIGS. 2 to 5.

First, the turntable 35 is made of aluminum or the like, and is provided with an annular recess 38 with an open upper end between a central cylindrical portion 36 and an outer cylindrical portion 37. Note that the center cylindrical portion 36
A truncated cone-shaped central convex portion 40 having a center hole 39 is integrally provided at the center of the upper end surface.
The upper end surfaces of the central cylindrical portion 36 and the outer cylindrical portion 37 are flush with each other, and a horizontal disk mounting surface 41 is formed by these upper end surfaces. The outer diameter of this disk mounting surface 41 is configured to be approximately equal to the outer diameter of the yoke 26 of the disk 24.

Next, a leaf spring 43, a yoke 44, a magnet 45, and a spacer 46 each having an annular shape are housed in the recess 38. At this time, first, the leaf spring 43
is placed on the bottom surface 38a of the recess 38 by, for example, three elastic pieces 47 that are integrally provided on the outer periphery and bent downward. and the leaf spring 4
A yoke 44 is placed horizontally on top of the yoke 44.
For example, three screw insertion bosses 48 integrally provided on the lower end surface 44a of the plate spring 43 are fitted into, for example, three boss fitting holes 49 provided in the leaf spring 43. For example, three stepped screws 50 are respectively inserted into the boss 48 from above, and the yoke 44 is attached to the recess 38 so as to be movable vertically within a certain range by these stepped screws 50. . That is, as shown in FIG. 5, the stepped screw 50 has a large-diameter shaft portion 50b provided at the bottom of the head 50a, and a small-diameter threaded portion 50c at the bottom of the shaft portion 50b. Then, the stepped screw 50 is inserted by the shaft portion 50b into the shaft insertion hole 51 provided in the lower end 48a of the boss 48, and the threaded portion 50c is screwed into the screw hole 52 provided in the bottom surface 38a of the recess 38. It is fixed in place.

Next, a magnet 45 is placed horizontally on the upper end surface 44b of the yoke 44 with its lower end surface 45a, and this magnet 45 is attracted onto the yoke 44 by its own suction force. A spacer 46 is placed on the upper end surface 45b of the magnet 45.
are fixed horizontally with adhesive etc. Note that this spacer 46 may be formed of any material, but
For example, a material having appropriate hardness and as high a friction coefficient as possible, such as hard rubber, is preferable.

According to the turntable device configured as described above, the recess 38 of the turntable 35
A magnet 45 housed therein is configured to be movable vertically within a certain range together with the yoke 44. Furthermore, the magnet 45 is moved upward together with the yoke 44 by the elastic piece 47 of the leaf spring 43, and as shown in FIG. 4A, the spacer 46
protrudes above the disk mounting surface 41 to a predetermined height h. Note that the projection height h of the spacer 46 is regulated by the lower end 48a of the boss 48 of the yoke 44 coming into contact with the lower surface of the head 50a of the stepped screw 50. Further, vertical guide grooves 54 provided on the outer periphery of the yoke 44, magnet 45, and spacer 46 are vertically slidable in vertical ribs 53 provided on the inner periphery of the outer cylindrical portion 37 of the turntable 35. The magnets 45 are fitted together, and the magnets 45 are configured to rotate together with the turntable 35. Furthermore, turntable 35
is rotationally driven by a drive shaft 55 such as a motor shaft.

Next, a description will be given of how the disk cartridge is attached to the turntable device configured as described above.

First, before installing the cartridge 21,
As shown in FIG. 4A, a spacer 46 projects above the disk mounting surface 41 of the turntable 35 to a predetermined height h.

Next, as shown in FIG. 4B, when the cartridge 21 is mounted at a predetermined height position relative to the turntable 35 by a cartridge loading mechanism (not shown), the disk 24 is moved to the yoke 26 of the disk holder 25. The disk is placed horizontally on the disk placement surface 41 of the turntable 35. At this time, the lower end 29a of the center pin 29 of the disk holder 25 and the center recess 33 are aligned with the center hole 39 of the turntable 35 and the center protrusion 4.
0, the disc 24 is fitted to the turntable 35 without any play, and the disc 24 is centered with respect to the turntable 35. Further, the disk holder 25 and the disk 24 are pushed up to a predetermined height above the lower half 23 within the cartridge 21 against the compression spring 30, so that the disk 24 can rotate smoothly within the cartridge 21.

However, at this time, the magnet 45 is brought into close contact with the yoke 26 on the lower surface of the disk holder 25 via the spacer 46, and between the magnet 45 and both the upper and lower yokes 26, 44, the center cylindrical portion 36 and the outer peripheral cylindrical portion of the turntable 35 are attached. Magnetic circuits φ ₁ and φ ₂ passing through the portion 37 are formed. And its magnetic circuit φ ₁
The yoke 26 is horizontally attracted to the disk mounting surface 41 by the attraction force of the magnet 45 generated at φ ₂ . On the other hand, at this time, the yoke 26 presses the magnet 45 downward through the spacer 46, so the magnet 45, together with the yoke 44 on its lower surface, sinks downward in the recess 38 against the leaf spring 43, as shown in FIG. As shown, the gap g between the yoke 26 on the lower surface of the disk holder 25 and the magnet 45 is regulated by the thickness of the spacer 46.

After mounting the cartridge 21 as described above, the turntable 35 is rotationally driven by the drive shaft 55, and the disk 24 in the cartridge 21, which is adsorbed on the disk mounting surface 41, is integrated with the turntable 35. It is rotated to perform desired recording and playback.

According to the turntable device of the present invention configured as described above, the disk 24 is connected to the turntable 3.
The turntable 35 is placed horizontally on a disk mounting surface 41 formed at the upper end surface of the turntable 35 and is attracted to it, and the height of the disk mounting surface 41 is higher than that of the metal etc. forming the turntable 35. It can be specified with high precision by the leveling accuracy of . Therefore turntable 3
The mounting height (vertical position) of the disk 24 mounted on the disc 24 can be determined with high precision, and unlike rubber or the like, it is not affected by aging.

In addition, the magnet 45 is protected by the spacer 46, and when the disc 24 is mounted on the turntable 35, the magnet 45 sinks downward against the leaf spring 43, thereby buffering the impact when the disc 24 is mounted. As a result, it is possible to prevent the magnet 45 from being accidentally damaged due to impact etc. when the disk 24 is attached.
The magnet 45 can be protected extremely reliably.

Also, with the disk 24 mounted on the turntable 35, the magnet 45 is attached to the yoke 26.
are always in close contact with each other via a spacer 46, and the gap g between the yoke 26 and the magnet 45 can be regulated by the thickness of the spacer 46. Therefore, by selecting the thickness of the spacer 46, the gap g can be set accurately, and the attraction force (adsorption force) of the disk 24 by the magnet 45 determined by the gap can be set to an accurate value. You can. As a result, the suction force (adsorption force) can be accurately set to an appropriate value, and the disk 24 can be prevented from slipping when the turntable 35 rotates.

Particularly, in the case of the magneto-optical disk 24, etc., it is considered to attach glass to the disk due to problems such as flatness, and an increase in the mass of the disk 24 is expected. And if the mass of the disk 24 is increased,
Since the moment of inertia is increased, the turntable 35 is
However, the disk 24 becomes slippery, and the response to starting and stopping rotation of the disk 24 becomes very poor. However, in this case, as described above, the suction force of the magnet 45 can be adjusted extremely easily by simply selecting the thickness of the spacer 46.
Even if the mass of the turntable 35 is increased, the disc 24 can be prevented from slipping relative to the turntable 35 in an extremely simple manner.

Further, the magnet 45 is fitted into the rib 53 of the turntable 35 by the guide groove 54 and rotated together with the turntable 35, and the spacer 46 fixed on the magnet 45 is moved by the leaf spring 43 to the disk. It is constantly pressed by the yokes 26 of 24. Therefore, if the spacer 46 is made of a material with a high coefficient of friction, such as rubber,
The frictional force between the spacer 46 and the yoke 26 can also exert the effect of preventing the disc 24 from slipping against the turntable 35, and the above-mentioned gap g can be adjusted accurately. The effect of preventing the disc 24 from slipping against the turntable 35 is very high.

Furthermore, since the gap g between the yoke 26 and the magnet 45 is not affected by the thickness of the magnet 45, the thickness accuracy of the magnet 45 may be very low. Therefore, the machining accuracy of the magnet 45 can be made very low, and the manufacture of the magnet 45 is very easy.

Furthermore, by simply inserting the magnet 45 into the recess 38, the magnet 45 is attracted onto the yoke 44 by its own suction force, so it is not necessary to fix the magnet 45 onto the yoke 44 by adhesive or the like. There is no problem at all, and the assembly of the magnet 45 is very simple.

Although the embodiments of the present invention have been described above, various modifications can be made based on the technical idea of the present invention.

For example, in the embodiment, the leaf spring 43 is used as the urging means.
Although a disc spring, a coil spring, and other various members having an elastic effect can be used.

In addition, in the embodiment, the annular magnet 45 is
However, for example, it is also possible to use a plurality of cylindrical magnets arranged in a circular shape.

Further, in the embodiment, a disk cartridge in which the disk 24 is housed in the cartridge 21 is used, but if the disk is used only for playback, the cartridge is unnecessary, and if the disk is provided with a yoke on the lower surface of the center part, the cartridge is not needed. Any disk may be used.

[Application example]

The present invention is a turntable device that can be widely applied to video discs, audio discs, and other disc players that record and reproduce various digital signal information or analog signal information.

[Effect of idea]

As mentioned above, the present invention allows the mounting height (vertical position) of the disc to be defined with high precision by the disc mounting surface which is formed with high precision by the surface of the metal etc. that is the upper end surface of the turntable. Moreover, it is completely unaffected by aging. Therefore, there is no problem of deviation in the distance between the pickup and the disk or skew, and the recording and reproducing characteristics can be significantly improved.

Further, according to the present invention, in addition to protecting the magnet with the spacer, when the disk is attached, the magnet can be sunk downward against the urging means to buffer the impact when the disk is attached. It is possible to prevent the magnet from being accidentally damaged due to shock when the disk is attached, and has extremely high durability and reliability.

Further, according to the present invention, the magnet is always in close contact with the yoke of the disk via the spacer, and the gap between the yoke and the magnet can be regulated by the thickness of the spacer. By selecting, the gap can be adjusted accurately. Therefore, the attraction force of the disk by the magnet can be accurately set to an appropriate value, and the disk can be prevented from slipping against the turntable. As a result, very good response to starting and stopping disk rotation can be obtained.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a conventional example of a turntable device in a video disc player.
2 to 5 show an embodiment of a turntable device in a video disc player to which the present invention is applied, and FIG. 2 is an exploded perspective view;
Figure 3 is a perspective view of the state in use, Figures 4A and 4B
The figure is a cross-sectional view explaining the mounting status of the disk.
The figure is an enlarged sectional view of the main parts with the disk attached. Also, in the symbols used in the drawings, 24...
Disc, 26...Yoke, 35...Turntable, 41...Disc mounting surface, 43...Leaf spring, 44...Yoke, 45...Magnet, 46
...It is a spacer.

Claims (1)

[Scope of utility model registration request] A recess with an open upper end is provided in the turntable, a magnet with a yoke attached to the lower end surface is installed in the recess, and the disc is placed on the turntable and is attracted by the attraction force of the magnet. In a turntable device configured to be attracted onto a turntable, the upper end surface of the turntable forms a disk mounting surface, and the magnet is movable within a certain range in the vertical direction together with the yoke within the recess. A spacer is fixed to the upper end surface of the magnet, and the magnet is moved upward together with the yoke by a biasing means to cause the spacer to protrude upward from the disk mounting surface of the turntable. is energized, and a disk with a yoke on the lower surface of the center is placed on the disk mounting surface of the turntable and attracted by the suction force of the magnet. The turntable device is characterized in that the turntable device is configured to press the magnet downward through the spacer so that the magnet sinks downward against the urging means.