Optical pickup device
AssigneeSamsung Electronics Co., Ltd.
InventorsSe June Park, Seok Jung Kim
Life of this patent
Estimating the term…
Abstract
An optical pickup device to provide a stable operation in both low-speed and high-speed modes by controlling a change in natural frequency, the optical pickup device including: a lens holder to support an objective lens; a supporting unit spaced apart from the lens holder; and a plurality of suspension members each having one end fixed to the lens holder and another end supported by the supporting unit to enable a movement of the lens holder, wherein the supporting unit includes a fixing member, a coupling portion provided in the fixing member to couple each suspension member, magnetic fluid received in the coupling portion, and an excite device to apply a magnetic field to the magnetic fluid.
Claims17
An optical pickup device comprising:
- a lens holder to support an objective lens;
- a supporting unit spaced apart from the lens holder;
- and
- one or more suspension members, each having one end fixed to the lens holder and another end supported by the supporting unit, to enable a movement of the lens holder, wherein
- the supporting unit comprises:
- a fixing member;
- one or more coupling portions provided in the fixing member to couple each suspension member therein;
- a magnetic fluid receiving portion disposed in each of the one or more coupling portions and surrounding the suspension member;
- magnetic fluid disposed in the magnetic fluid receiving portion to surround a portion of each suspension member;
- and
- an excite device disposed in the magnetic fluid receiving portion to directly surround the magnetic fluid to apply a magnetic field to the magnetic fluid,
- the one or more coupling portions comprising:
- a first coupling portion having a first elastically deformable coupling agent provided therein;
- a second coupling portion spaced apart from the first coupling portion and having a second elastically deformable coupling agent provided therein;
- and
- a space between the first coupling portion and the second coupling portion having the magnetic fluid provided therein.
A method of stably supporting an objective lens in an optical pickup device the method comprising:
- fixing a first end of one or more suspension members to a lens holder that holds the objective lens, and a second end of each suspension member to a supporting unit of the optical pickup device to enable a movement of the lens holder;
- and
- supplying power to a magnetic fluid surrounding the one or more suspension members in the supporting unit in order to apply a magnetic field to the magnetic fluid and control a length of a deformable portion of each suspension member and supplying the power to at least one excite coil provided on the supporting unit,
- wherein the at least one excite coil comprises a first excite coil on a first side of the supporting unit to apply a first magnetic field and a second excite coil on a second side of the supporting unit, different from the first side, to apply a second magnetic field,
- wherein the supplying of the power to the at least one excite coil comprises:
- supplying a first amount of power to the at least one excite coil when the optical disk drives rotates in a low-speed mode to apply a first magnetic field to the magnetic fluid such that the magnetic fluid has a first viscosity and the deformable portion of each suspension member has a first length;
- and
- supplying a second amount of power, greater than the first amount of power, to the at least one excite coil when the optical disk drives rotates in a high-speed mode to apply a second magnetic field to the magnetic fluid such that the magnetic fluid has a second viscosity, greater than the first viscosity, and the deformable portion of each suspension member has a second length, less than the first length.
Dependencies are inferred from the claim text.