Dynamic information storage or retrieval – Dynamic mechanism subsystem – Specific detail of storage medium support or motion production
Reexamination Certificate
2002-07-15
2004-12-28
Chen, Tianjie (Department: 2652)
Dynamic information storage or retrieval
Dynamic mechanism subsystem
Specific detail of storage medium support or motion production
Reexamination Certificate
active
06836460
ABSTRACT:
TECHNICAL FIELD
This invention relates to a disc rotational driving device used for rotationally driving a disc-shaped recording medium such as an optical disc or a magneto-optical disc.
BACKGROUND ART
Conventionally, optical recording media such as optical discs and a magneto-optical discs have been used as recording media for information signals. Recording/reproducing devices for recording/reproducing information signals to/from such discs have been provided and broadly used.
In a recording/reproducing device of this type, a disc rotational driving device for positioning, holding and rotationally driving a disc is provided. The disc rotational driving device has a motor
103
which includes a case
101
having a rotor housed therein and a rotary shaft
102
attached to the rotor and having a part protruding outward from the case
101
, as shown in FIG.
1
.
At the distal end of the portion of the motor shaft of the rotary shaft
102
protruding from the case
101
, a turntable
104
of an integral structure is mounted. This turntable
104
is formed in a substantially circular plate-like shape and has a center hole provided at its central part. The turntable
104
is mounted at one end of the rotary shaft
102
by having the rotary shaft
102
pressed into the center hole. At the center of the turntable
104
, a protruding centering portion
105
is provided. This centering portion
105
is engaged with a positioning hole
202
provided at the center of a disc
201
and aligns the center of rotation of the disc
201
with the center of rotation of the turntable
104
, thus centering the disc
201
on the turntable
104
. As the inner circumference of the positioning hole
202
is placed on the circumferential surface of the centering portion
105
of the turntable
104
, the disc
201
is positioned and thus held. By driving the motor
103
in this state, the disc
201
is rotationally driven together with the rotor, the rotary shaft
102
and the turntable
104
.
In a recording/reproducing device having such a disc rotational driving device, an optical pickup device
203
is arranged to face the disc
201
which is rotationally driven by the rotation of the disc rotational driving device, and the signal recording area is scanned by a light beam emitted from the optical pickup device
203
, thereby recording/reproducing an information signal.
In the recording/reproducing device having the disc rotational driving device as described above, a predetermined spacing must be formed between the disc
201
supported by the turntable
104
and the side of the case
101
of the motor
103
, that is, the proximal end side of the rotary shaft
102
protruding from the case
101
, because a disc loading mechanism including a disc tray for carrying the disc
201
into the recording/reproducing device from outside, the optical pickup device
203
, and a guide shaft
204
or the like for supporting the optical pickup device
203
movably in the radial direction of the disc
201
are provided there.
Therefore, the rotary shaft
102
of the motor
103
must protrude from the case
101
by a predetermined length or longer. The turntable
104
must be mounted on the distal end side of the rotary shaft
102
.
Since the turntable
104
is mounted on the distal end side of the rotary shaft, there is a long distance between the rotor housed in the case
101
of the motor
103
and the disc
201
supported by the turntable
104
, and the rotor of the motor
103
and the disc
201
are connected with each other only by the rotary shaft
102
. Therefore, the torsional rigidity of the whole system is lowered and a resonance frequency of torsional resonance is generated in a low-frequency band.
If a resonance frequency of torsional resonance is generated in a low-frequency band as described above, torsional resonance might be generated in the rotary shaft
102
or the like when the disc
201
is rotationally driven. Therefore, accurate rotation of the disc
201
is disturbed by such resonance.
DISCLOSURE OF THE INVENTION
In view of the foregoing status of the art, it is an object of the present invention to provide a disc rotational driving device which restrains torsional resonance generated in the rotary shaft of the motor as a driving source for rotationally driving the disc, and enables stable and accurate rotation of the disc.
A disc rotational driving device according to the present invention comprises: a motor in which a rotary shaft attached to a rotor housed in a case is provided to protrude from the case; and a turntable having a setting portion for setting a disc thereon and mounted on the proximal end side of the portion of the rotary shaft protruding from the case so as to cover the proximal end portion of the rotary shaft.
In this device, a positioning portion for positioning the disc is provided on the distal end side of the rotary shaft.
Another disc rotational driving device according to the present invention comprises: a motor having a rotary shaft attached to a rotor having a smaller diameter than the diameter of a disc; and a turntable having a setting portion for setting the disc thereon and a cylindrical portion provided to protrude inward, and mounted on the proximal end side of the rotary shaft so as to cover the proximal end side of the rotary shaft by the cylindrical portion.
The other objects and advantages of the present invention will be further clarified from the following description of the embodiment.
REFERENCES:
patent: 3658347 (1972-04-01), Cheeseboro
patent: 3912283 (1975-10-01), Hammond et al.
patent: 5761794 (1998-06-01), Choi
patent: 6038206 (2000-03-01), Mukawa
patent: 6160780 (2000-12-01), Furukawa et al.
patent: 6181671 (2001-01-01), Ikawa et al.
patent: 6510122 (2003-01-01), Yamauchi et al.
patent: 05325365 (1993-12-01), None
patent: 5-325365 (1993-12-01), None
patent: 6-203446 (1994-07-01), None
patent: 06203446 (1994-07-01), None
patent: 8-096459 (1996-04-01), None
Nagasaka Hideo
Osada Yasuo
Tamura Renji
Chen Tianjie
Oblon, Spivak, McClelland, Maier & Neusadt, P.C.
Sony Corporation
LandOfFree
Disk drivingly rotating device with centering mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disk drivingly rotating device with centering mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk drivingly rotating device with centering mechanism will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3286327