Optical Pickup Device
AssigneeMitsubishi Electric Corporation
InventorsToshiya Matozaki, Nobuo Takeshita
Life of this patent
Estimating the term…
Abstract
An optical pickup device includes an objective lens (1) for focusing a light flux onto an information layer of a disk-shaped medium, an objective lens driving unit that drives the objective lens (1) in a focus servo direction and in a tracking servo direction, a correction lens (14) disposed on the same optical axis as the objective lens (1), and a correction lens driving unit that drives the correction lens (14) in the same direction as the focus servo direction to control the condition of the light flux incident on the objective lens.
Claims20
-22. (canceled)
An optical pickup device comprising:
- an objective lens for focusing a light flux on an information layer of a disk-shaped medium;
- an objective lens driving unit that drives said objective lens in a focus servo direction and in a tracking servo direction;
- a correction lens disposed on the same optical axis as said objective lens, a correction lens holder holding said correction lens;
- at least one shaft that guides said correction lens holder in the same direction as said focus servo direction, and
- a correction lens driving unit that drives said correction lens holder in the same direction as said focus servo direction to control a state of said light flux incident on said objective lens,
- wherein said correction lens driving unit includes:
- an electromagnetic coil for generating a driving force in said tracking servo direction, and
- a magnetic piece and a magnet for generating a biasing force that biases said correction lens holder against said shaft in a direction opposite to said driving force generated by said electromagnetic coil, and
- wherein said correction lens driving unit controls current flowing through said electromagnetic coil to thereby control a force with which said correction lens holder is urged against said shaft in such a manner that a friction force between said correction lens holder and said shaft is smaller in the case of driving said correction lens than in the case of keeping said correction lens holder in resting state.
Dependencies are inferred from the claim text.