Patent Number: 
Section: claims

1. An X-ray phase grating used for X-ray phase-contrast imaging based on Talbot interference, comprising:a first substrate having a first pattern in which first faces and second faces making an angle of α with the first faces are periodically arranged, where α≠0 and α≠90°; anda second substrate having a second pattern in which third faces and fourth faces making an angle of α with the third faces are periodically arranged;wherein the first substrate and the second substrate are configured integrally with each other,wherein the second pattern has a same period as the first pattern, andwherein the first pattern and the second pattern are combined so as to be shifted from each other. 2. The X-ray phase grating according to claim 1, wherein the first faces are parallel to the third faces, and the second faces are parallel to the fourth faces. 3. The X-ray phase grating according to claim 1, wherein the first pattern and the second pattern are formed on different substrates. 4. The X-ray phase grating according to claim 3, wherein a region between the first pattern and the second pattern is filled with a material having a different refractive index from a material forming the first and second patterns. 5. The X-ray phase grating according to claim 1, wherein the first substrate and the second substrate are the same substrate, and the first pattern and the second pattern are formed on opposing sides of the same substrate. 6. The X-ray phase grating according to claim 1, wherein the angle between the first faces and the plane of the substrate having the first faces decreases from the center to the periphery of the first substrate, and the angle between the third faces and the plane of the substrate having the third faces decreases from the center to the periphery of the second substrate. 7. The X-ray phase grating according to claim 1, wherein the first pattern and the second pattern are formed in two dimensions. 8. The X-ray phase grating according to claim 1,wherein the first pattern and the second pattern are shifted from each other by one half period of the first pattern and the second pattern. 9. The X-ray phase grating according to claim 1,wherein a shape of the second pattern is the same as a shape of the first pattern, andwherein the third faces correspond to the first faces and the fourth faces correspond to the second faces. 10. An X-ray phase grating used for X-ray phase-contrast imaging based on Talbot interference, comprising:a first substrate having a first pattern in which first faces and second faces making an angle of α with the first faces are periodically arranged, where α≠0 and α≠90°; anda second substrate having a second pattern in which third faces and fourth faces making an angle of α with the third faces are periodically arranged;wherein the first pattern and the second pattern are combined so as to be shifted from each other,wherein the first pattern and the second pattern are formed on different substrates, andwherein the first substrate having the first pattern and the second substrate having the second pattern have joint portions for joining the substrates. 11. The X-ray phase grating according to claim 10,wherein the second pattern has a same period as the first pattern. 12. The X-ray phase grating according to claim 11,wherein the first pattern and the second pattern are shifted from each other by one half period of the first pattern and the second pattern. 13. The X-ray phase grating according to claim 10,wherein the first pattern and the second pattern are shifted from each other by one half period of the first pattern and the second pattern. 14. An X-ray phase grating used for X-ray phase-contrast imaging based on Talbot interference, comprising:a first substrate having a first pattern in which first faces and second faces making an angle of α with the first faces are periodically arranged, where α≠0 and α≠90°; anda second substrate having a second pattern in which third faces and fourth faces making an angle of α with the third faces are periodically arranged;wherein the first pattern and the second pattern are combined so as to be shifted from each other,wherein the first pattern and the second pattern are formed on different substrates, andwherein the first substrate is in contact with the second substrate. 15. The X-ray phase grating according to claim 14,wherein the second pattern has a same period as the first pattern. 16. The X-ray phase grating according to claim 14,wherein the first pattern is in contact with the second pattern. 17. The X-ray phase grating according to claim 14,wherein a face, of the first substrate, opposing to a face on which the first pattern is formed is in contact with a face, of the second substrate, opposing to a face on which the second pattern is formed. 18. A Talbot interferometer comprising:the X-ray phase grating according to claim 1, anda detector detecting interference fringes reflecting a shape of the X-ray phase grating. 19. A Talbot interferometer comprising:the X-ray phase grating according to claim 10, anda detector detecting interference fringes reflecting a shape of the X-ray phase grating. 20. A Talbot interferometer comprising:the X-ray phase grating according to claim 11, anda detector detecting interference fringes reflecting a shape of the X-ray phase grating.