Optical pickup device
AssigneeFunai Electronic Co., Ltd.
InventorKenji Okamoto
Life of this patent
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Abstract
An optical pickup device includes a light source configured to output laser light, an objective lens configured to converge the laser light emitted from the light source onto an optical disc, a sensor lens including a lens surface on which return light reflected by the optical disc is incident and that is also configured to generate an astigmatism in the return light, and a light-receiving element configured to receive the return light which has passed through the sensor lens 40 and to generate a focus error signal based on the received return light. The lens surface includes a first curvature radius in a first direction and a second curvature radius different from the first curvature radius in a second direction that is perpendicular or substantially perpendicular to the first direction.
Claims19
An optical pickup device comprising:
- a light source that outputs laser light;
- an objective lens that converges the laser light emitted from the light source onto an optical disc;
- a sensor lens including a lens surface on which return light reflected by the optical disc is incident or from which the return light exits and that generates an astigmatism in the return light;
- and
- a light receiver that receives the return light which has passed through the sensor lens and generates a focus error signal based on the received return light;
- wherein
- the lens surface includes a first curvature radius in a first direction and a second curvature radius different from the first curvature radius in a second direction that is perpendicular or substantially perpendicular to the first direction, and
- the lens surface is concave in the first direction and convex in the second direction.
An optical pickup device, comprising:
- a light source that outputs laser light;
- an objective lens that converges the laser light emitted from the light source onto an optical disc;
- a sensor lens including a lens surface on which return light reflected by the optical disc is incident or from which the return light exits and that generates an astigmatism in the return light;
- and
- a light receiver that receives the return light which has passed through the sensor lens and generates a focus error signal based on the received return light;
- wherein
- the lens surface includes a first curvature radius in a first direction and a second curvature radius different from the first curvature radius in a second direction that is perpendicular or substantially perpendicular to the first direction, and
- no element of the optical pickup device is positioned between the sensor lens and the light receiver;
- and
- the sensor lens includes a spherical surface provided on an opposite side of the lens surface.
Dependencies are inferred from the claim text.