Dynamic information storage or retrieval – Dynamic mechanism subsystem – Specific detail of storage medium support or motion production
Reexamination Certificate
1998-06-05
2001-01-23
Ometz, David L. (Department: 2754)
Dynamic information storage or retrieval
Dynamic mechanism subsystem
Specific detail of storage medium support or motion production
Reexamination Certificate
active
06178156
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a disk recording and reproduction apparatus for recording and reproducing information to and from a disk used as a recording medium. More particularly, it relates to a dynamic damper for damping vibration in a disk recording and reproduction apparatus which positions its head by linearly moving the head in the radial direction of the disk.
As having been disclosed in Japanese Laid-open Patent Application, Publication No. Hei 2-292781 for the invention of “A voice-coil type optical head” for example, a conventional disk recording and reproduction apparatus comprises a disk drive mechanism for supporting and rotating a disk used as a recording medium, an optical head for writing and reading information to and from the disk, and a positioning mechanism for positioning the optical head. The conventional disk recording and reproduction apparatus having been configured as described above is provided with a dynamic damper having a function to damp vibration in a specific direction so that the optical head can be accurately positioned at a target track on the disk.
The dynamic damper of the conventional disk recording and reproduction apparatus disclosed in Japanese Laid-open Patent Application, Publication No. Hei 2-292781 comprises a weight having a large mass and an elastic element. The weight is bonded to the elastic element which is fixed to a member whose vibration is to be damped. By using the dynamic damper being configured described above, the conventional disk recording and reproduction apparatus damp vibration from the drive mechanism to some extent, to improve the positioning accuracy of the optical head.
Generally speaking, with an increase in the mass of a dynamic damper, a frequency range of vibration to be damped becomes wide. However, it is very difficult to bond a weight having a large mass to an elastic element having a viscosity, in particular, a gel material. For this reason, the frequency range of vibration to be damped cannot be made wider, thereby causing a problem in product reliability.
In addition, in the above-mentioned conventional configuration, it is necessary to install a dynamic damper in each direction of vibration to be damped, thereby causing a problem of making the apparatus larger and heavier.
BRIEF SUMMARY OF THE INVENTION
In order to solve the above-mentioned problems, an object of the present invention is to provide a dynamic damper capable of damping vibration in a wide frequency range by using a simple configuration, and to provide a disk recording and reproduction apparatus using the dynamic damper. In addition, another object of the present invention is to provide a dynamic damper capable of delivering an excellent damping effect for vibration in any directions, for example, in the directions of three axes (X, Y and Z axes) which fall at right angles with respect to each other, and to provide a disk recording and reproduction apparatus using the dynamic damper.
In order to attain the above-mentioned objects, the dynamic damper of the present invention comprises:
a weight having a predetermined mass;
a pair of viscoelastic elements having a predetermined spring constant and a predetermined viscosity and used to support the weight; and
a holder for securing the weight onto a substrate via the viscoelastic elements,
said dynamic damper being configured to damp vibration in a frequency range lower than a resonance frequency determined by the spring constant of the viscoelastic elements and the mass of the weight.
Furthermore, in the dynamic damper of the present invention, the weight is sandwiched between the pair of viscoelastic elements.
With this configuration of the dynamic damper of the present invention, a weight having a large mass for the dynamic damper can be set easily, and a frequency range of vibration to be damped can be made wider.
Furthermore, in the dynamic damper of the present invention, the viscoelastic elements are formed in a plate shape and each have a through hole at the center of the flat surface thereof, the weight is formed in a cylindrical shape, and the through holes of the viscoelastic elements are passed through by a rod secured to the center axis of the weight. With this configuration of the dynamic damper of the present invention, a weight having a large mass can be attached to the viscoelastic elements easily and securely.
Furthermore, in the dynamic damper of the present invention, the holder is installed on the substrate so that the center axis of the weight is orthogonal to the line segment extended between the rotation center of a disk and the operating point of a head for writing and reading information on and from the disk. With this configuration of the dynamic damper of the present invention, the highest damping effect can be delivered.
Furthermore, the dynamic damper of the present invention comprises:
a spherical weight having a predetermined mass;
six rods projecting radially from the weight at equal intervals;
a set of viscoelastic elements having a predetermined spring constant and a predetermined viscosity, being passed through by the rods and used to elastically support the weight; and
a substrate for supporting the weight via the viscoelastic elements,
said dynamic damper being configured to damp vibration in a frequency range lower than a resonance frequency determined by the spring constant of the viscoelastic elements and the mass of the weight.
With this configuration of the dynamic damper of the present invention, a weight having a large mass for the dynamic damper can be set easily, and a vibration damping effect can be obtaining in any directions.
Furthermore, the dynamic damper of the present invention comprises:
a weight having a predetermined mass;
a first viscoelastic element having a predetermined spring constant and a predetermined viscosity,
a second viscoelastic element having a spring constant and a viscosity different from those of the first viscoelastic element, and used together with the first viscoelastic element to support the weight; and
a holder for securing the weight onto a substrate via the first and second viscoelastic elements,
dynamic damper being configured to damp vibration in a frequency range lower than a resonance frequency determined by the spring constants of the first and second viscoelastic elements and the mass of the weight.
With this configuration of the dynamic damper of the present invention, a weight having a large mass for the dynamic damper can be set easily, and a vibration damping effect can be obtaining in any directions.
In order to attain the above-mentioned objects, the disk recording and reproduction apparatus of the present invention comprises:
a disk used as a recording medium;
a disk drive mechanism for supporting and driving the disk;
a head for writing and reading information to and from the disk;
a head positioning mechanism for moving the head in the radial direction of the disk;
a substrate for supporting the disk drive mechanism and the head positioning mechanism; and
a dynamic damper including a weight having a predetermined mass, a set of viscoelastic elements having a predetermined spring constant and a predetermined viscosity and used to support the weight, and a holder for securing the weight onto the substrate via the viscoelastic elements,
said disk recording and reproduction apparatus being configured to damp vibration in a frequency range lower than a resonance frequency determined by the spring constant of the viscoelastic elements and the mass of the weight by using the dynamic damper.
With this configuration of the disk recording and reproduction apparatus of the present invention, a weight having a large mass for the dynamic damper can be set easily, and a frequency range of vibration to be damped can be made wider.
Furthermore, the disk recording and reproduction apparatus of the present invention comprises:
a disk used as a recording medium;
a disk drive mechanism for supporting and driving the disk;
a head for writing and reading information to and from the d
Kuwajima Hideki
Okamoto Hirotaka
Akin Gump Strauss Hauer & Feld L.L.P.
Castro Angel
Matsushita Electric - Industrial Co., Ltd.
Ometz David L.
LandOfFree
Disk recording and reproduction apparatus and dynamic damper... 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 recording and reproduction apparatus and dynamic damper..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disk recording and reproduction apparatus and dynamic damper... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2539830