Dynamic information storage or retrieval – Dynamic mechanism subsystem – Specific detail of storage medium support or motion production
Reexamination Certificate
1998-07-01
2001-12-11
Davis, David (Department: 2652)
Dynamic information storage or retrieval
Dynamic mechanism subsystem
Specific detail of storage medium support or motion production
Reexamination Certificate
active
06330220
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vibration preventing mechanism for a motor for rotating a turntable to which a disc is attached for reading information recorded on the disc and a disc apparatus using such a vibration preventing apparatus.
2. Description of the Related Art
A compact disc (having a diameter of 12 cm or 8 cm) which is reproduced by a laser pick-up is used as a recording medium for storing information such as database or software. In order to incorporate a disc apparatus using such a recording medium into a notebook-type personal computer having a reduced size, a built-in type CD-ROM drive unit which is incorporated into a housing of the notebook-type personal computer.
In a conventional apparatus, a tray on which a disc is placed is driven by a motor. That is, when the tray is moved outside a housing, a disc is placed on the turntable of the tray and, then, the tray is returned inside the housing by a drive force of the motor.
Reduction in size and thickness of a disc apparatus has been achieved by reducing not only the size of the tray and a driving mechanism for driving the tray but also the size of a pickup and the motor for rotating a turntable on which the disc is placed. Accordingly, a supporting structure for a rotational shaft of a motor for driving the turntable and the supporting structure for transmitting a torque to the rotational shaft receive an influence of the reduction in thickness.
In such a conventional disc apparatus, a rotational speed of the disc is increased up to twelve times or even sixteenth times faster than a standard speed so as to quickly read data (information) recorded on the disc. If the disc is rotated at such a high speed, a vibration is easily generated due to a center of gravity being slightly displaced from the center of rotation since a strength of supporting structures of the rotational shaft and a rotor in the motor for rotating the turn table is reduced.
For example, if the center of gravity of the disc is displaced from the center of rotation due to a displacement of a center hole or an uneven distribution of printing ink provided on a surface of the disc, a vibration is generated when the disc is rotated at a high speed. Such a vibration generated in the disc is transmitted to a pickup via the turntable and, thereby, the information recorded on the disc cannot be read by the pickup. In such a case, a control unit of the disc apparatus has to reduce the rotational speed of the motor for driving the turntable which results in a reduction in the reading speed.
Accordingly, there is a problem in that the reading speed cannot be increased even when the rotational speed of the disc can be increased twelve times or sixteen times faster than the standard speed since the rotational speed of the disc is decreased to a speed at which a vibration is not generated.
Additionally, if the vibration of the disc is transmitted to a base which supports the motor via the turntable and the motor, the vibration may be transmitted also to a housing of the notebook-type personal computer. Thus, there is a problem in that such a vibration provides an unpleasant feel to an operator or a movable part such as a tray vibrates, which results in generation of a rattling noise.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved and useful vibration preventing mechanism for a motor and a disc apparatus using such a vibration preventing mechanism.
A more specific object of the present invention is to provide a vibration preventing mechanism for a motor which prevents generation of a vibration caused by an uneven distribution of weight in rotational parts including a turntable, and a disc apparatus using such a vibration preventing apparatus.
In order to achieve the above-mentioned objects, there is provided according to the present invention a vibration preventing mechanism for a motor, comprising:
a rotatable rotor provided in the motor; and
a plurality of weights provided in the rotor, each of the weights being displaced by a vibration caused by a rotation of the rotor.
According to the above-mentioned invention, if a vibration is generated when the rotor is rotated at a high speed, the vibration of the rotor can be suppressed by the plurality of weights being displaced to positions where the vibration is attenuated.
In the above-mentioned invention, the plurality of weights may rotate about a rotational axis of the rotor. According to this invention, a compact structure can be achieved since the plurality of weights rotate about the rotational axis of the rotor.
Additionally, the plurality of weights may be movably provided in an annular space having a center coinciding with a rotational axis of said rotor. According to this invention, a compact structure can be achieved since the plurality of weights are movably provided in the annular space having the center coinciding with the rotational axis of the rotor. Additionally, if a vibration is generated when the rotor is rotated at a high speed, the vibration of the rotor can be suppressed by the plurality of weights move within the annular space and reach the positions where the vibration is attenuated.
Additionally, the rotor may include a guide surface guiding movement of the plurality of weights. Accordingly, each of the weights can quickly and positively move to the position where the vibration is suppressed.
Additionally, each of the plurality of weights may include a plurality of balls which roll on the guide surface of the rotor. Accordingly, a friction of the weights can be reduced when the weights moves along the guide surface. Thus, the plurality of weights can quickly move to the positions where the vibration is attenuated.
Additionally, there is provided according to another aspect of the present invention a disc apparatus using a disc as a recording medium, the disc apparatus comprising:
a turntable to which the disc is attached;
a motor for rotating the turntable, the motor including a rotor; and
a vibration preventing mechanism including a plurality of weights provided in the rotor, each of the weights being displaced by a vibration caused by a rotation of the rotor.
Accordingly, if a vibration generated due to a high-speed rotation of the disc is transmitted to the rotor, the plurality of weights are displaced to positions where the vibration is attenuated so as to suppress the vibration of the rotor, which can increase a speed for reading information recorded on the disc.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.
REFERENCES:
patent: 3854347 (1974-12-01), Hellerich
patent: 4060009 (1977-11-01), Wyman
patent: 5111713 (1992-05-01), Cameron et al.
patent: 5280828 (1994-01-01), Reynoso et al.
patent: 5386163 (1995-01-01), Heilman
patent: 5391952 (1995-02-01), Simazu et al.
patent: 5860865 (1999-01-01), Smith
patent: 6005311 (1999-12-01), Matsushima
patent: 6205110 (2001-03-01), Miyamoto et al.
patent: 60-154356 (1985-08-01), None
patent: 60-215137A (1985-10-01), None
patent: 63-259242A (1988-10-01), None
patent: 59-210565 (1994-11-01), None
Katoh Noriyuki
Shiga Naoto
Anderson Kill & Olick P.C.
Davis David
Sanyo Seimitsu Co., Ltd
LandOfFree
Vibration preventing mechanism and a disc apparatus having... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vibration preventing mechanism and a disc apparatus having..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vibration preventing mechanism and a disc apparatus having... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2585566