JP2004247032A5

JP2004247032A5 -

Info

Publication number: JP2004247032A5
Application number: JP2004009479A
Authority: JP
Filing date: 2004-01-16
Publication date: 2006-03-30

Claims

A light source;
A beam shaping lens for shaping an elliptical divergent beam emitted from the light source into a substantially circular divergent beam;
A collimating lens for converting the substantially circular divergent beam into a substantially parallel beam;
An objective lens for condensing the substantially parallel beam on an optical information recording medium;
In an optical head comprising a detector for detecting a beam reflected by the optical information recording medium,
The beam shaping lens has a pair of cylindrical surfaces curved in the same direction, one of the cylindrical surfaces is an aspherical surface, and the other cylindrical surface is a spherical surface.

2. The optical head according to claim 1, wherein the beam shaping lens has an aspherical cylindrical surface near the light source and a spherical surface far from the light source.

The optical head according to claim 1, wherein the beam shaping lens has a quadrangular cross-sectional shape perpendicular to the optical axis.

The optical head according to claim 1, wherein a material of the beam shaping lens is glass.

2. The optical head according to claim 1, wherein a fixed position between the base on which the beam shaping lens is mounted and the beam shaping lens is closer to the light source than the center of the beam shaping lens.

The optical head according to claim 1, wherein the base on which the beam shaping lens is mounted and the beam shaping lens are fixed on a plane perpendicular to a central axis of a cylindrical surface of the beam shaping lens.

The optical head according to claim 1, wherein the base on which the beam shaping lens is mounted and the beam shaping lens are pressure-bonded by a spring that is pressed along a central axis direction of a cylindrical surface of the beam shaping lens.

The optical head according to claim 1, wherein the beam shaping lens includes two cylindrical lenses, and the two cylindrical lenses are bonded to each other.

The optical head according to claim 8, wherein a surface where the two cylindrical lenses are joined is a flat surface.

9. The optical head according to claim 8, wherein the two cylindrical lenses have different cross-sectional sizes perpendicular to the optical axis.

The optical head according to claim 10, wherein the two cylindrical lenses have a larger cross-sectional size perpendicular to the optical axis than that of the cylindrical lens close to the light source.

9. The optical head according to claim 8, wherein the two cylindrical lenses have different thicknesses along the optical axis.

The optical head according to claim 12, wherein the two cylindrical lenses are thicker in thickness along the optical axis and closer to the light source.

The optical head according to claim 1, wherein the light source and the beam shaping lens are fixed to the same holder.

The optical head according to claim 14, wherein the holder has a tilt adjustment mechanism for correcting an optical axis inclination of the light source.

The optical head according to claim 14, wherein the holder has a position adjusting mechanism for correcting a position error of a light emitting point of the light source.

The optical head according to claim 14, wherein the holder is press-fitted into the optical stage of the optical head by a press.

The optical head according to claim 14, wherein the holder is fixed by caulking with respect to an optical stage of the optical head.

The optical head according to claim 14, wherein the holder is welded to an optical bench of the optical head.

The optical head according to claim 1, wherein the collimating lens is movable in the optical axis direction.

A light source;
A beam shaping lens for shaping an elliptical divergent beam emitted from the light source into a substantially circular divergent beam;
A collimating lens for converting the substantially circular divergent beam into a substantially parallel beam;
An objective lens for condensing the substantially parallel beam on an optical information recording medium;
In an optical head comprising a detector for detecting a beam reflected by the optical information recording medium,
The optical head according to claim 1, wherein a fixed position between the base on which the beam shaping lens is mounted and the beam shaping lens is on the light source side from the center of the beam shaping lens.

The optical head according to claim 21, further comprising an adhesive applied only to a side of the beam shaping lens close to the light source in order to bond the beam shaping lens and the base.

The optical head according to claim 21, further comprising an elastic body that presses the beam shaping lens on a side closer to the light source of the beam shaping lens.

The optical head according to claim 21, wherein the base has a convex shape with respect to the beam shaping lens on a side close to the light source.

The optical head according to claim 21, wherein the base has a concave shape with respect to the beam shaping lens between a side close to the light source and a side far from the light source.

An optical head according to claim 1;
A rotation system or a transfer system for relatively moving the optical head and the optical information recording medium;
An optical information recording / reproducing apparatus comprising: a control circuit that controls the optical head, the rotating system, and the transfer system based on a signal obtained from the optical head.

27. A computer comprising the optical information recording / reproducing apparatus according to claim 26 as an external storage device.

27. A video recording / reproducing apparatus comprising the optical information recording / reproducing apparatus according to claim 26, which records and reproduces video on an optical information recording medium.

27. A video reproducing apparatus comprising the optical information recording / reproducing apparatus according to claim 26, and reproducing an image from an optical information recording medium.

A server comprising the optical information recording / reproducing device according to claim 26 as an external storage device.

A car navigation system comprising the optical information recording / reproducing device according to claim 26 as an external storage device.

A beam shaping lens for shaping an elliptical divergent beam emitted from a semiconductor laser light source into a substantially circular divergent beam,
Having a pair of cylindrical surfaces curved in the same direction;
A beam shaping lens, wherein one cylindrical surface is an aspherical surface and the other cylindrical surface is a spherical surface.

The beam shaping lens according to claim 32, wherein the cylindrical surface close to the semiconductor laser light source is an aspherical surface, and the cylindrical surface far from the semiconductor laser light source is a spherical surface.

The beam shaping lens according to claim 32 or 33, wherein the material is glass.

The beam shaping lens according to any one of claims 32 to 34, wherein the cylindrical surface close to the semiconductor laser light source is a convex surface.

36. The beam shaping lens according to claim 32, which has a flat surface perpendicular to the central axis of the pair of cylindrical surfaces.

37. The beam shaping lens according to claim 32, wherein a ratio of a minor axis to a major axis of the substantially circular divergent beam after shaping is in a range of 1: 1 to 1: 2.