US 2006/0140072 A1 · Optical pickup

Abstract

An optical pickup records information on an optical recording medium and retrieves information from the optical recording medium by radiating a light beam on the optical recording medium. The optical pickup includes a light source which emits the light beam. The optical pickup also includes an object lens which directs the convergent light beam to a recording layer of the optical recording medium. The optical pickup further includes an aberration correction lens assembly located between the light source and the object lens. The aberration correction lens assembly includes at least one movable lens which is movable in an optical axis direction. The aberration correction lens assembly moves the movable lens to convert the light beam to a convergent light beam or a divergent light beam so as to correct spherical aberration. A distance between a principal plane of the aberration correction lens assembly on a light emergent side and a principal plane of the object lens falls within a range determined in accordance with a numerical aperture of the object lens, a focal length of the aberration correction lens assembly on the light emergent side, and a focal length of the object lens.

Claims15

Dependent claims

1-19. (canceled)

An optical pickup adapted to radiate a light beam which is eventually transformed into a plurality of beam spots on an optical recording medium and to record information on the optical recording medium and retrieve information from the optical recording medium by radiating the light beam on the optical recording medium, the optical pickup comprising:

a light source for emitting the light beam;
an object lens for converging the light beam into a convergent light beam to direct the convergent light beam to the optical recording medium;
and
an aberration correction lens assembly located between the light source and the object lens, the aberration correction lens assembly including at least one movable lens which is movable in an optical axis direction, the aberration correction lens assembly controlling a movement of the movable lens to correct spherical aberration, wherein a distance between a principal plane of a lens in the aberration correction lens assembly on the most light emergent side and a principal plane of the object lens is determined by the following equation:
(
f
2
+
f
3
)
-
10
⁢
f
3
2
3
⁢
NA
4
<
e
2
<
(
f
2
+
f
3
)
+
10
⁢
f
3
2
3
⁢
NA
4
where e2 represents the distance between the principal plane of the lens in the aberration correction lens assembly on the most light emergent side and the principal place of the object lens, NA represents a numerical aperture of the object lens, f2 represents a focal length of the aberration correction lens assembly on the light emergent side, and f3 represents a focal length of the object lens.

40 more elements

Dependencies are inferred from the claim text.

Facts

Application

11/357,111Filed 21 Feb 2006

Priority

JP 2001-26381731 Aug 2001

Published

29 Jun 2006

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

G11B 7/13927
Active, e.g. controlled by electrical or mechanical means: during transducing, e.g. to correct for variation of the spherical aberration due to…
G11B 7/1378
Lenses: separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
G11B 7/0948
With provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record…
G11B 2007/0013
For carriers having data stored in three dimensions, e.g. volume storage: for carriers having multiple discrete layers

Family

Application10/227,480Continuation · filed 26 Aug 2002

Application11/357,111Continuation · filed 21 Feb 2006

US 2003/0081530 A1Published application

US 7,054,252 B2Related patent

US 7,417,939 B2Related patent

US 2006/0140072 A1This patent

From the US filing history. Foreign family members aren’t listed.

Optical pickup

Life of this patent

Optical pickup

Life of this patent

Abstract

Claims15