Patent Number: 
Section: claims

1. A radiation phase change detection method for detecting a phase change of a radiation, the radiation phase change detection method comprising changing an interference state of the radiation using a phase grating configured to cause interference in the radiation radiated by a radiation source, a scintillator configured to convert the radiation into light, and a two-dimensional optical image pickup element,wherein the two-dimensional optical image pickup element is incapable of sampling a period of a self-image of the radiation generated through the phase grating, and is capable of sampling interference fringes generated between the period of the self-image and a period of a pixel pitch of the two-dimensional optical image pickup element. 2. A radiation phase change detection method according to claim 1, further comprising placing an object between the radiation source and the phase grating, or between the phase grating and the scintillator. 3. A radiation phase change detection method according to claim 1, further comprising arranging the two-dimensional optical image pickup element so that, when the period of the self-image is defined as D1, and the pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2. 4. A radiation phase change detection method according to claim 3, further comprising arranging the two-dimensional optical image pickup element so that the interference fringes formed by D1 and D2 have a period of 2 times D2 or more and 100 times D2 or less. 5. A radiation phase change detection method for detecting a phase change of a radiation, the radiation phase change detection method comprising:arranging a two-dimensional optical image pickup element, which includes a scintillator, so that, when a period of a self-image generated through a phase grating is defined as D1, and a pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2, and so that interference fringes formed by D1 and D2 depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D2 or more and 100 times D2 or less;acquiring a phase change of the interference fringes before and after insertion of an object; andoutputting an image on a phase change of the radiation caused by at least the insertion of the object. 6. A radiation phase change detection method according to claim 5, further comprising adjusting the relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image through rotation so that the interference fringes have a period of 100 times D2 or less. 7. A radiation phase change detection method according to claim 5, wherein the scintillator comprises a scintillator capable of resolving 100 lp/mm at least with a thickness of 150 μm. 8. A radiation phase change detection method according to claim 5, wherein the scintillator comprises a eutectic phase-separated scintillator, in which a plurality of fiber structures containing GdAlO3 are surrounded by a material containing Al2O3. 9. A radiation phase change detection method according to claim 5, further comprising arranging a fiber optic plate, which has a periodicity of half the period D1 of the self-image or less, between the scintillator and the two-dimensional optical image pickup element. 10. A radiation imaging apparatus, comprising:a radiation source;a phase grating configured to cause interference in a radiation radiated by the radiation source;a scintillator configured to convert the radiation into light; anda two-dimensional optical image pickup element,wherein the two-dimensional optical image pickup element is incapable of sampling a period of a self-image of the radiation generated through the phase grating, and is capable of sampling interference fringes generated between the period of the self-image and a period of a pixel pitch of the two-dimensional optical image pickup element. 11. A radiation imaging apparatus according to claim 10, wherein the two-dimensional optical image pickup element is arranged so that, when the period of the self-image is defined as D1, and the pixel pitch of the two-dimensional optical image pickup element is defined as D2=k*D1, k falls in a range of ½<k≤3/2. 12. A radiation imaging apparatus according to claim 10, wherein the two-dimensional optical image pickup element is arranged so that the interference fringes formed by D1 and D2 have a period of 2 times D2 or more and 100 times D2 or less. 13. A radiation imaging apparatus, comprising:a radiation source;a phase grating;a scintillator; anda two-dimensional optical image pickup element,wherein the radiation imaging apparatus is configured to detect a phase change of a radiation by:arranging the two-dimensional optical image pickup element so that, when a period of a self-image generated through the phase grating is defined as D1, and a pixel pitch of the two-dimensional optical image pickup element, which includes the scintillator, is defined as D2=k*D1, k falls in a range of ½<k≤3/2, and so that interference fringes formed depending on a relationship in arrangement of the two-dimensional optical image pickup element with respect to the self-image have a period of 2 times D2 or more and 100 times D2 or less;acquiring a phase change of the interference fringes before and after insertion of an object; andoutputting an image on a phase change of the radiation caused by at least the object. 14. A radiation imaging apparatus according to claim 13, wherein the radiation source comprises an X-ray source. 15. A radiation imaging apparatus according to claim 13, further comprising at least one selected from the group consisting of a driving system, an arithmetic section, and an image acquisition unit.