Optical head, and optical recording and reproducing apparatus
AssigneeMinolta Co., Ltd.
InventorsHiroshi Hatano, Kazuyuki Ogura, Akira Sato, Yujiro Suzuki
Life of this patent
Estimating the term…
Abstract
An optical head has a near-field light generating element generating near-field light; and a beam shaper which shapes an incident beam into a substantially coroidal beam and directs the shaped beam to said near-field light generating element. According to the optical head having the above-described structure, the incident light is shaped into a substantially toroidal beam without being intercepted, incident on the zonal part of the near-field light generating element, and condensed to a minute spot. That is, only the light of the high numerical aperture part is used with efficiency, and the light can be condensed to a minute spot.
Claims22
An optical head comprising:
- a near-field light generating element generating near-field light;
- and
- a beam shaper which shapes an incident beam into a substantiallycoroidal beam and directs the shaped beam to said near-field light generating element.
An optical head as claimed inclaim 1, wherein the beam shaper has a first axicon lens and a secondaxicon lens coaxially disposed so that concave and convex conical surfaces and thereof are opposed to each other.
An optical head comprising:
- a near-field light generating element which generates near-field light;
- and
- a beam splitter which splits an incident light into a plurality of beams and directs the split beams to said near-field light generating element.
An optical apparatus comprising:
- a light source which emits a beam;
- and
- an optical head, having
- a near-field generating element generating near-field light emitted from the light source;
- and
- a beam shaper which shapes an incident beam into a substantially toroidal beam and directs the shaped beam to said near-field light generating element.
An optical apparatus comprising:
- a light source which emits a beam;
- and
- an optical head, having
- a near-field generating element generating near-field light emitted from the light source;
- and
- a beam splitter which splits an incident light into a plurality of beams and directs the split beams to said near-field light generating element.
Dependencies are inferred from the claim text.