1. An optical apparatus, comprising:
a decentered optical system having an element with variable optical properties, and
a driving circuit for driving the element with variable optical properties, wherein the element with variable optical properties has a rotationally asymmetric light deflection action.
2. The optical apparatus according to claim 1, which further comprises an optical element having a rotationally symmetric surface.
3. The optical apparatus according to claim 1, which further comprises an optical element having a rotationally symmetric aspheric surface.
4. The optical apparatus according to claim 1, which further comprises an optical element having an action of diverging a light beam.
5. The optical apparatus according to claim 1, wherein:
the decentered optical system comprises a plurality of optical surfaces, and
light incident on the decentered optical system forms an image at a given position, wherein of the plurality of optical surfaces, an optical surface on which light is first incident is fixed relative to the image formed at the given position.
6. The optical apparatus according to claim 4, which further comprises an optical element adapted to move along an optical axis of the decentered optical system.
7. The optical apparatus according to claim 1, which comprises a plurality of rotationally symmetric optical elements.
8. The optical apparatus according to claim 1, which comprises an optical surface comprising a curved surface, wherein:
the optical surface is located on an entrance side of the element with variable optical properties, on which light rays are incident.
9. The optical apparatus according to claim 1, wherein:
an exit side of the element with variable optical properties, from which light rays emerge, is free from an optical surface having a curved surface.
10. The optical apparatus according to claim 1, comprising:
a plurality of optical elements that are located on an entrance side of the element with variable optical properties, on which light rays are incident, and an exit side of the element with variable optical properties, from which light rays emerge.
11. The optical apparatus according to claim 1, wherein:
the element with variable optical properties has a reflecting surface, and
the element with variable optical properties is located such that an optical axis of the element with variable optical properties on an entrance side thereof is substantially orthogonal to an optical axis of the element with variable optical properties on an exit side thereof.
12. The optical apparatus according to claim 1, wherein:
the element with variable optical properties has a reflecting surface, and
the element with variable optical properties is located such that an optical axis of the element with variable optical properties on an entrance side thereof makes an angle of 5\xb0 to 60\xb0 inclusive with the normal to the reflecting surface.
13. The optical apparatus according to claim 1, which further comprises a stop located in the decentered optical system, wherein light incident on the decentered optical system forms an image at a given position, and the stop is fixed relative to an image fanned at the given position.
14. The optical apparatus according to claim 5, further comprising an optical element in addition to the element with variable optical properties.
15. The optical apparatus according to claim 1, further comprising a plurality of optical elements, wherein:
light incident on the decentered optical system forms an image at a given position, and
the plurality of optical elements are fixed relative to an image formed at the given position.
16. The optical apparatus according to claim 5, further comprising a plurality of optical elements, wherein:
the plurality of optical elements each have a curved surface.
17. The optical apparatus according to claim 5, further comprising an optical element having a rotationally symmetric surface.
18. The optical apparatus according to claim 1, wherein the element with variable optical properties is a reflecting mirror with a variable surface shape.
19. The optical apparatus according to claim 18, wherein:
an amount of displacement, \u0394, of the surface shape from a quadratic surface of revolution is \u0394\u226610 mm.
20. The optical apparatus according to claim 1, wherein:
the element with variable optical properties is located at a position where a chief ray is higher than a marginal ray.
21. The optical apparatus according to claim 1, wherein:
the element with variable optical properties is located at a position where a chief ray is lower than a marginal ray.
22. The optical apparatus according to claim 1, wherein:
the decentered optical system has an odd number of reflecting surfaces, and the optical apparatus comprises an image inverting portion.
23. The optical apparatus according to claim 1, wherein:
the decentered optical system has one reflecting surface.
24. The optical apparatus according to claim 1, comprising a plurality of the elements with variable optical properties.
25. The optical apparatus according to claim 24, further comprising an optical element in addition to the element with variable optical properties.
26. The optical apparatus according to claim 24, wherein:
two of the plurality of the elements with variable optical properties are located such that the normal to an optical surface of one element with variable optical properties has a torsional relation to the normal to an optical surface of another element with variable optical properties.
27. The optical apparatus according to claim 24, wherein:
two of the plurality of the elements with variable optical properties are located such that the normal to an optical surface of one element with variable optical properties and the normal to an optical surface of another element with variable optical properties lie in a same plane.
28. The optical apparatus according to claim 25, wherein:
the decentered optical system comprises two elements with variable optical properties, between which an optical element is interposed.
29. The optical apparatus according to claim 25, wherein:
the decentered optical system comprises two elements with variable optical properties, which are located adjacent to each other.
30. The optical apparatus according to claim 24, wherein:
the plurality of elements with variable optical properties each have an action of inducing a change in light deflection properties, and comprise an element with variable optical properties, which induces a given change upon changing from a first state to a second state, and an element with variable optical properties, which induces an opposite change to the given change upon changing from the first state to the second state.
31. The optical apparatus according to claim 24, wherein:
the plurality of elements with variable optical properties each have an action of inducing a change in light deflection properties, and comprise two elements with variable optical properties, which induce a given change upon changing from a first state to a second state.
32. The optical apparatus according to claim 24, wherein:
the decentered optical system comprises a variable-optical-property element having a convex surface shape and a variable-optical-property element having a concave surface shape in a given state.
33. The optical apparatus according to claim 1, further comprising an optical element having a rotationally asymmetric optical surface.
34. The optical apparatus according claim 1, comprising a plurality of the optical elements having a rotationally asymmetric optical surface.
35. The optical apparatus according to claim 18, which satisfies the following condition:
\u0394<(\u2155)\xd7D\u2003\u2003(2)
where \u0394 is an amount of displacement of the surface shape from a quadratic surface of revolution, and D is a diameter of a circle having an area the same as an area of a portion of the element with variable optical properties through which a light beam transmits.
36. The optical apparatus according to claim 18, which satisfies either one of the following conditions:
0\u2266|PIPTOT|<1000\u2003\u2003(12)
0\u2266|PVPTOT|<1000\u2003\u2003(13)
where PI is a reciprocal of a radius of primary curvature near an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, PV is a reciprocal of a radius of primary curvature farther from an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, and PTOT is a reciprocal of a focal length of the optical system.
37. The optical apparatus according to claim 18, which satisfies either one of the following conditions:
0.00001\u2266|\u0394PIPTOT|<1000\u2003\u2003(14)
\u20030.00001\u2266|\u0394PVPTOT|<1000\u2003\u2003(15)
where PI is a reciprocal of a radius of primary curvature near an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, PV is a reciprocal of a radius of primary curvature farther from an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, and PTOT is a reciprocal of a focal length of the optical system.
38. The optical apparatus according to claim 18, which satisfies the following condition:
0\u2266|PIPV cos \u03c6|<100\u2003\u2003(20)
where PI is a reciprocal of a radius of primary curvature near an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, PV is a reciprocal of a radius of primary curvature farther from an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, and \u03c6 is an angle of incidence of an axial ray on a surface of the mirror.
39. The optical apparatus according to claim 18, which satisfies the following condition:
0.1\u2266|fNfTOT|\u2003\u2003(22)
where fN is a focal length of an N-th optical element other than a free-form surface optical element and fTOT is a focal length of the optical system.
40. The optical apparatus according to claim 18, which satisfies the following condition:
0.0001\u2266|PI||Pm|<10\u2003\u2003(23-1)
0.0001\u2266|PV||Pm|<10\u2003\u2003(24-1)
where PI is a reciprocal of a radius of primary curvature near an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, PV is a reciprocal of a radius of primary curvature farther from an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, and Pm is an inverse of a focal length of an optical element having a shortest focal length in the optical system.
41. The optical apparatus according to claim 18, which satisfies either one of the following conditions:
\u20030\u2266|PI|\u22660.01 (mm\u22121)\u2003\u2003(16-3)
0\u2266|PV|\u22660.01 (mm\u22121)\u2003\u2003(16-4)
where PI is a reciprocal of a radius of primary curvature near an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis, and PV is a reciprocal of a radius of primary curvature farther from an entrance surface out of radii of primary curvature of the variable mirror in a vicinity of an optical axis.
42. The optical apparatus according to claim 24, wherein:
the element with variable optical properties is a reflecting mirror having a variable surface shape satisfying the following condition:
0.0001\u2266|HJHK|<10000\u2003\u2003(8)
where HJ is a maximum quantity of transformation of a first one of the plurality of elements with variable optical property, and HK is a maximum quantity of transformation of a second one of the plurality of elements with variable optical property.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A magnetic recording medium comprising:
a substrate;
a magnetic recording layer; and
a metal alloy heatsink layer between the substrate and the magnetic recording layer.
2. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a single phase.
3. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer has a thermal conductivity of at least about 100 Wm-K.
4. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer has a thermal conductivity of at least about 300 Wm-K.
5. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer has a hardness corresponding to a maximum scratch depth of less than 3 nm based upon a standard nanoscratch test.
6. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer has a thickness of from about 20 to about 500 nm.
7. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer has a thickness of from about 100 to about 300 nm.
8. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises CuZr or AgPd.
9. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a CuZr alloy comprising from about 0.1 to about 1 atomic percent Zr with the balance comprising Cu and incidental impurities.
10. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a CuZr alloy comprising from about 0.2 to about 0.4 atomic percent Zr with the balance comprising Cu and incidental impurities.
11. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a AgPd alloy comprising from about 0.1 to about 30 atomic percent Pd with the balance comprising Ag and incidental impurities.
12. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a AgPd alloy comprising from about 0.5 to about 20 atomic percent Pd with the balance comprising Ag and incidental impurities.
13. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a face centered cubic crystal structure.
14. The magnetic recording medium of claim 13, wherein the magnetic recording layer comprises an L10 crystal structure.
15. The magnetic recording medium of claim 14, wherein the magnetic recording layer comprises a CoPt, FePt or FeNiPt alloy.
16. The magnetic recording medium of claim 15, wherein the metal alloy heatsink layer comprises AgPd.
17. The magnetic recording medium of claim 1, wherein the metal alloy heatsink layer comprises a face centered cubic crystal structure with (111) texture.
18. The magnetic recording medium of claim 17, wherein the magnetic recording layer comprises a hexagonal crystal structure.
19. The magnetic recording medium of claim 18, wherein the magnetic recording layer comprises a CoPtCr or RECo alloy.
20. The magnetic recording medium of claim 19, wherein the metal alloy heatsink layer comprises CuZr.
21. The magnetic recording medium of claim 1, further comprising at least one seedlayer between the substrate and the metal alloy heatsink layer.
22. The magnetic recording medium of claim 1, further comprising at least one seedlayer between the metal alloy heatsink layer and the magnetic recording layer.
23. The magnetic recording medium of claim 1, further comprising at least two seedlayers between the metal alloy heatsink layer and the magnetic recording layer, wherein one of the seedlayers comprises Ta and another of the seedlayers comprises Pt.
24. A heatsink film comprising a substantially single phase metal alloy selected from CuZr and AgPd.
25. A heat assisted magnetic recording system comprising:
a magnetic recording medium comprising a magnetic recording layer and an underlying metal alloy heatsink layer; and
a heat assisted magnetic recording head positionable adjacent to the magnetic recording medium.