1. A magnetic memory, comprising:
a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;
an interlayer dielectric;
an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and
a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,
wherein said underlayer includes:
a first magnetic underlayer; and
a non-magnetic underlayer formed on said first magnetic underlayer, and
wherein said first magnetic underlayer is formed with such a thickness that said first magnetic underlayer does not exhibit in-plane magnetic anisotropy in a portion of said first magnetic underlayer formed on said interlayer dielectric.
2. The magnetic memory according to claim 1, wherein the thickness of said first magnetic underlayer is adjusted so that said first magnetic underlayer does not exhibit ferromagnetism in the portion of said first magnetic underlayer formed on said interlayer dielectric.
3. The magnetic memory according to claim 2, wherein said first magnetic underlayer includes NiFe as a major constituent and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V.
4. The magnetic memory according to claim 3, wherein said first magnetic underlayer has a thickness in a range from 0.5 to 3 nm.
5. The magnetic memory according to claim 4, wherein the thickness of said first magnetic underlayer is less than 2 nm.
6. The magnetic memory according to claim 3, wherein a concentration of said at least one non-magnetic element in said first magnetic underlayer is in a range from 10 to 25 atomic %.
7. A magnetic memory, comprising:
a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;
an interlayer dielectric;
an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and
a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,
wherein said underlayer includes:
a first magnetic underlayer; and
a non-magnetic underlayer formed on said first magnetic underlayer, and
wherein said first magnetic underlayer includes NiFe as major constitution and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V, and
wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.
8. The magnetic memory according to claim 7, wherein the thickness of said first magnetic underlayer is less than 2 nm.
9. The magnetic memory according to claim 7, wherein a concentration of said at least one non-magnetic element in said first magnetic underlayer is in a range from 10 to 25 atomic %.
10. The magnetic memory according to claim 1, wherein said first magnetic underlayer is formed of magnetic material which intrinsically exhibits in-plane magnetic anisotropy, with such a thickness that a portion of said first magnetic underlayer disposed on said interlayer dielectric exhibits perpendicular magnetic anisotropy.
11. The magnetic memory according to claim 10, wherein said first magnetic underlayer includes Co or Fe as a major constituent and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V.
12. The magnetic memory according to claim 11, wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.
13. A magnetic memory, comprising:
a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of said magnetization fixed layer being fixed;
an interlayer dielectric;
an underlayer formed on upper faces of said magnetization fixed layer and said interlayer dielectric; and
a data recording layer formed on an upper face of said underlayer and having perpendicular magnetic anisotropy,
wherein said underlayer includes:
a first magnetic underlayer; and
a non-magnetic underlayer formed on said first magnetic underlayer, and
wherein said first magnetic underlayer includes Co or Fe as major constitution and includes at least one non-magnetic element selected from the group consisting of Zr, Ta, W, Hf and V, and
wherein a thickness of said first magnetic underlayer is in a range from 0.5 to 3 nm.
14. The magnetic memory according to claim 1, further comprising a second magnetic underlayer disposed between said non-magnetic underlayer and said data recording layer,
wherein said second magnetic underlayer includes at least one film stack including a layer of Pt or Pd and a layer of Fe, Co or Ni.
15. The magnetic memory according to claim 1, wherein said non-magnetic underlayer is formed of material selected from the group consisting of Pt, Au, Pd and Ir.
16. The magnetic memory according to claim 15, wherein a thickness of said non-magnetic underlayer is equal to or more than 0.5 nm and less than 3.0 nm.
17. The magnetic memory according to claim 1, wherein said non-magnetic underlayer is formed of a Ta film having a thickness of 0.1 to 2.0 nm.
18. A magnetic memory, comprising:
a ferromagnetic underlayer formed of magnetic material;
a non-magnetic intermediate layer disposed on said underlayer;
a ferromagnetic data recording layer formed on said intermediate layer and having perpendicular magnetic anisotropy;
a reference layer connected to said across a non-magnetic layer; and
first and second magnetization fixed layers disposed in contact with a bottom face of said underlayer,
wherein said data recording layer includes:
a magnetization free region having a reversible magnetization and opposed to said reference layer;
a first magnetization fixed region coupled to a first border of said magnetization free layer and having a magnetization fixed in a first direction; and
a second magnetization fixed region coupled to a second border of said magnetization free layer and having a magnetization fixed in a second direction opposite to said first direction;
wherein said intermediate layer is formed of a Ta film having a thickness of 0.1 to 2.0 nm.
19. The magnetic memory according to claim 18, wherein said underlayer is amorphous or has a microcrystalline structure.
20. The magnetic memory according to claim 18, wherein said underlayer includes at least one of Ni, Fe and Co as a major constitution, and includes at least one non-magnetic element selected from the group consisting of Zr, Hf, Ti, V, Nb, Ta, W, B and N.
21. The magnetic memory according to claim 18, wherein said data recording layer is formed of n film stacks in each of which first and second layers are layered, where n is a natural number,
wherein said first layer includes at least one material selected from the group consisting of Fe, Co and Ni, and
wherein said second layer is formed of material different from that of said first layer and includes at least one material selected from the group consisting of Fe, Co and Ni.
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. An image generation device which generates a reconstructed image from a light field image including sub-images taken from different viewpoints, the image generation device comprising:
a parameter acquiring section which acquires a photographing parameter in taking the light field image;
an information acquiring section which acquires region information that decides a region of the sub-images included in the light field image based on the photographing parameter;
a defining section which defines correspondence between a reconstructed pixel composing the reconstructed image and a sub-pixel in the region of the sub-images that was decided by the region information; and
a generating section which decides a pixel value of the reconstructed pixel based on a pixel value of the corresponding sub-pixel to generate the reconstructed image.
2. The image generation device according to claim 1, further comprising
a storage which stores pieces of region information that are associated with a condition of a photographing parameter,
wherein the information acquiring section acquires, from the pieces of region information stored in the storage, region information that matches a photographing parameter acquired by the parameter acquiring section.
3. The image generation device according to claim 1, wherein:
the light field image is an image photographed using a main lens and micro-lenses; and
the photographing parameter includes a parameter corresponding to at least one of an effective diameter of the main lens, a length at an object-to-be photographed side of a lens barrel that accommodates the main lens, and a length at a micro-lenses side of the lens barrel.
4. The image generation device according to claim 3, wherein:
in the region information, the larger a largest diameter of the main lens becomes, the smaller a difference in shape of the sub-images between a central portion close to an optical axis of the main lens and a peripheral portion far from the optical axis of the main lens becomes provided that the photographing parameter and other physical configuration of an optical system are the same.
5. The image generation device according to claim 3, wherein:
in the region information, the larger an effective diameter of the main lens becomes, the larger a region of the sub-images becomes provided that the photographing parameter and other physical configuration of an optical system are the same.
6. The image generation device according to claim 3, wherein:
in the region information, the longer either a length at the micro-lenses side of the lens barrel or a length at the object-to-be photographed side of the lens barrel becomes, the larger a difference in shape of the sub-images between a central portion close to an optical axis of the main lens and a peripheral portion far from the optical axis of the main lens becomes provided that the photographing parameter and other physical configuration of an optical system are the same.
7. The image generation device according to claim 3, wherein:
in the region information, a sub-image is defined, for each of the micro-lenses,
in such way that the farther the micro-lens becomes from an optical axis of the main lens, the larger distortion of a shape of a sub-image corresponding to the micro-lens becomes.
8. The image generation device according to claim 3, wherein:
in the region information, a sub-image is defined, for each of the micro-lenses,
in such a way that the larger either a distance between the micro-lenses or a distance between the micro-lens and an imaging area becomes, the larger a distance between centers of corresponding sub-images becomes.
9. The image generation device according to claim 1, wherein:
the region information defines, a region whose SN ratio is in an allowable range in taking a light field image with the corresponding photographing parameter, as a region of the sub-images.
10. A digital camera comprising:
a photographing section which uses a main lens and micro-lenses to take a light field image including sub-images taken from different viewpoints;
a parameter acquiring section which acquires a photographing parameter in taking the light field image;
an information acquiring section which acquires region information that decides a region of the sub-images included in the light field image based on the photographing parameter;
a defining section which defines correspondence between a reconstructed pixel composing a reconstructed image generated from the light field image and a sub-pixel in the region of the sub-images that was decided by the region information; and
a generating section which decides a pixel value of the reconstructed pixel based on a pixel value of the corresponding sub-pixel to generate the reconstructed image.
11. A method of generating a reconstructed image from a light field image including sub-images taken from different viewpoints, the method comprising steps of:
acquiring a photographing parameter in taking the light field image;
acquiring region information that decides a region of the sub-images included in the light field image based on the photographing parameter;
defining correspondence between a reconstructed pixel composing the reconstructed image and a sub-pixel in the region of the sub-images that was decided by the region information; and
deciding a pixel value of the reconstructed pixel based on a pixel value of the corresponding sub-pixel to generate the reconstructed image.
12. A non-transitory computer readable recording medium having stored thereof a program executable by a computer that controls an image generation device to generate a reconstructed image from a light field image that includes sub-images taken from different viewpoints, the program causing the computer to realize functions of:
acquiring a photographing parameter in taking the light field image;
acquiring region information that decides a region of the sub-images included in the light field image based on the photographing parameter;
defining correspondence between a reconstructed pixel composing the reconstructed image and a sub-pixel in the region of the sub-images that was decided by the region information; and
deciding a pixel value of the reconstructed pixel based on a pixel value of the corresponding sub-pixel to generate the reconstructed image.