US 6,310,840 B1 · Optical scanning device comprising a main lens and an auxiliary lens

Abstract

An optical player includes an optical scanning device. The scanning device includes an optical lens system for focusing a light beam into a scanning spot on a track of an information carrier. The scanning device includes a first actuator for displacing the lens system parallel to an optical axis for focusing the light beam on the information carrier. The lens system includes a main lens or objective lens and an auxiliary or solid immersion lens, providing the lens system with a large numerical aperture, so that the scanning device is suitable for scanning information carriers with a high information density, such as, for example, high density compact discs. The auxiliary lens is secured in a fixed position to a housing of the lens system, while the main lens is suspended in the housing in a direction parallel to the optical axis by an elastically deformable mounting unit. The lens system includes a second actuator for moving the main lens relative to the auxiliary lens in a direction parallel to the optical axis for compensating for spherical aberration in a transparent protection layer of the information carrier. Thus, the necessary power of the first actuator is limited considerably.

Claims19

Dependent claims

An optical scanning device including;

a radiation source for supplying a radiation beam during operation of the device;
an optical lens system for focusing the radiation beam into a scanning spot on a track of an information carrier, the lens system including:
a housing;
an auxiliary lens secured in a fixed position in the housing;
an elastically deformable mounting unit;
and a main lens elastically suspended in the housing by the mounting unit to move relative to the housing in a direction parallel to an optical axis of the lens system;
a first actuator for moving the lens system parallel to the optical axis;
and
a second actuator for moving the main lens relative to the auxiliary lens in the direction parallel to the optical axis.

6 more elements

An optical player comprising:

a table which can be rotated about an axis of rotation;
a radiation source for supplying a radiation beam during operation of the device;
an optical lens system for focusing the radiation beam into a scanning spot on a track of an information carrier, the lens system including:
a housing;
an auxiliary lens secured in a fixed position in the housing;
an elastically deformable mounting unit;
and a main lens elastically suspended in the housing by the mounting unit to move relative to the housing in a direction parallel to an optical axis of the lens system;
a first actuator for moving the lens system parallel to the optical axis;
a second actuator for moving the main lens relative to the auxiliary lens in the direction parallel to the optical axis;
and
a displacement device for displacing the lens system relative to the axis of rotation predominantly in a radial direction.

8 more elements

An optical lens system comprising:

a housing;
an auxiliary lens secured in a fixed position in the housing;
an elastically deformable mounting unit;
a main lens ellastically suspended in the housing by the mounting unit, the mein lens being movable relative to the housing in a direction paralell to an optical axis of the lens system;
a first actuator for moving the lens system parallel to the optical axis;
and
a second actuator for moving the main lens relative to the auxiliary lens in the direction parallel to the optical axis.

4 more elements

Dependencies are inferred from the claim text.

Optical scanning device comprising a main lens and an auxiliary lens

Life of this patent

Optical scanning device comprising a main lens and an auxiliary lens

Life of this patent

Abstract

Claims19