JPH0441488Y2 - - Google Patents

Description

[Detailed description of the invention] The invention is based on an alignment member having a conical surface so that the center hole of the disk is mounted without eccentricity on the rotating shaft that rotates the disk on which information signals are recorded in the form of pits. An object of the present invention is to provide a disk drive device in which an alignment member is prevented from slipping out by an elastic body installed between the turntable that supports the disk.

Recently, information signals such as audio signals are digitally recorded on a disk in the form of pits, and a laser beam is irradiated from a radiation source such as a semiconductor laser to read and reproduce the information signal from the disk. Audio disk (DAD)
Optical PCM playback devices such as these have been developed and are attracting attention.

By the way, the pit has a width of 0.5μm and a length of 0.89~
3.19μm, and the distance between adjacent pits is 1.6μm, which is extremely high density recording. Therefore, in a disk drive device, an important problem is how to eliminate eccentricity of the disk and drive the disk to rotate stably even against vertical vibrations.

Therefore, as shown in FIG. 1, a conical surface 4a is attached to the rotating shaft 3 of the motor 2 that rotates the disk 1, so that even if the disk has a center hole that deviates from the standard depending on the product, it can be rotated without eccentricity. It has been proposed that a centering member 4 having a centering member 4a is attached so that the disk 1 is placed in close contact with the disk 1 without eccentricity.

This alignment member 4 is urged upward by a spring 9 provided on a turntable 7 that holds the disk 1, urges the disk 1 upward, and is pressed and held against the turntable 7 by a pressing member 10. do.

By the way, since the alignment member 4 is normally urged upward by the spring 9, it is necessary to prevent the alignment member 4 from coming off.

Therefore, a method of preventing the centering member 4 from coming off by providing retaining members 6, 6 on the inner surface of the turntable 7 can be considered.

However, since the focal length of the objective lens of the pick-up 14 has a numerical aperture of NA≒0.5, the pick-up 14 is extremely close to the disk surface, and furthermore, the disk mounting portions 7b, 7b of the turntable 7 that holds the disk 1 are The larger the area of contact with the disc 1, the more stable the disc 1 can be held, so I would like to use it to fill the entire label surface of the disc 1 as much as possible.

Therefore, since the turntable 7 is inserted between the pick-up 14 and the disk 1, a retaining member 6 is attached to the inner surface of the turntable 7.
However, installing two very thin layers requires an extremely precise technique, and a problem arises in that the precision of the disk mounting portions 7b, 7b is lost.

Therefore, the purpose of this invention is to develop a disk drive device that has such high-density recorded data.
To provide a disk drive device capable of stably holding a disk and with less axial wobbling of a rotating shaft.

The present invention will be described in detail below with reference to the drawings.

Note that the same numbers are given to the same parts as in Fig. 1.

The disk 1 is placed on an alignment member 4 having a conical surface, which is slidably attached to a motor shaft 3 rotated by a motor 2, and is driven to rotate. Conical surfaces 4a, 4a having a larger diameter on the lower end side and a smaller diameter on the upper end side are formed on the outer periphery of the alignment member 4. The diameter of the large diameter portion of the lower end of the conical surfaces 4a, 4a is larger than the center hole 5 of the disk 1, and the diameter of the small diameter portion of the upper end of the conical surfaces 4a, 4a is smaller than the diameter of the center hole 5 of the disk 1.

In addition, the relatively thick bottom portions 4b, 4 of the aligning member 4
Cylindrical through holes 4c, 4c are formed in b. Retaining members 6, 6 are press-fitted into the through holes 4c, 4c to prevent the centering member 4 from slipping out.

Passing holes 7a, 7a are formed in the lower surface of the turntable 7 corresponding to the through holes 4c, 4c of the alignment member 4. 8, 8 is a retaining ring. Reference numeral 9 is an elastic body, one end of which is fixed on a turntable 7 fixed to the motor shaft 3, and is configured to urge the centering member 4 upward. 10 is a disk pressing body provided on the opening/closing lid 11. 12
is an outer case that covers the disk pressing body 10. 1
Numerals 3 and 13 are springs provided between the pressing body 10 and the outer case 12, which urge the pressing body 10 downward.

In such a configuration, before the disk 1 is mounted on the alignment member 4, the alignment member 4 is urged upward by the elastic body 9, but the retaining rings provided on the retaining members 6, 6 The upward sliding movement of the aligning member 4 is restricted by the contact of the centering members 8, 8 with the bottom surfaces 7c, 7c of the turntable 7.

Since the present invention has such a configuration, through holes 4 are provided in the bottom portions 4b, 4b of the centering member 4, which has a relatively thick wall.
c, 4c are formed, and passage holes 7a, 7a are formed in the relatively thick bottom portions 7c, 7c of the turntable 7, through which the retaining members 6, 6 are configured to pass. Therefore, it can be extremely easy to manufacture.

Furthermore, since the distance from the centering member to the motor is relatively long, the retaining member can be sufficiently long, making it easy to manufacture.

Therefore, according to the present invention, a retaining member is formed on the bottom surface of the centering member, which has a relatively thick wall, and on the bottom surface of the turntable against eccentricity of the disk and vibration in the vertical direction. , there is no adverse effect on the rotational drive of the disk.

Further, since the distance from the centering member to the motor is relatively long, the retaining member can be made sufficiently long without considering accuracy, which has the advantage of being easy to manufacture.

Furthermore, since there is no member fixed to the rotating shaft to prevent the alignment member from coming off, the rotating shaft can be shortened accordingly, or if the length of the rotating shaft is the same, the turntable can rotate by that much. The length of fixation to the shaft can be increased, allowing the disk to be held stably. Furthermore, since no heavy object such as a retaining yoke is attached above the rotating shaft, shaft vibration of the motor can be reduced, and in this respect, the turntable can be driven stably.

The retaining member is installed by effectively utilizing the space on the underside of the turntable. This retaining member allows the alignment member and the turntable to rotate together, so that the aligning member and the turntable can rotate together. Damage to the disk due to different rotations does not occur.

[Brief explanation of drawings]

FIG. 1 shows a conventional disk drive device, and FIG. 2 shows a disk drive device according to the present invention. DESCRIPTION OF SYMBOLS 1... Disk, 2... Motor, 3... Motor shaft, 4... Aligning member, 4a, 4a... Conical surface, 4b, 4b... Aligning member bottom part, 4c, 4c
... Through hole, 5 ... Center hole, 6, 6 ... Removal prevention member, 7 ... Turntable, 7a, 7a ... Passing hole, 7b, 7b ... Disk mounting part, 7c, 7
c... Bottom part, 8, 8... Retaining ring, 9... Elastic body, 10... Pressing body, 14... Pick up.

Claims (1)

[Scope of utility model registration request] a turntable fixed to a rotating shaft of a motor that rotates the disk and on which the disk is placed; and a conical surface that engages with a center hole formed in the disk;
A disk drive device comprising an alignment member slidably supported on a rotating shaft above the turntable, and an elastic body that biases the alignment member in a direction away from the turntable. A retaining member is provided on the lower surface of the core member to be inserted into a passage hole formed in the turntable, and a lower part of the retaining member is in contact with the lower surface of the turntable to move the alignment member relative to the turntable. A disk drive device characterized by being provided with a locking portion.