Patent Number: 
Section: claims

1. A stimulable phosphor sheet for a radiation image recording and reproducing method comprising the steps of recording a radiation image as a latent image, irradiating the latent image with stimulating rays to release stimulated emission, and electrically processing the emission to reproduce the radiation image, comprising a stimulable phosphor-containing grid partition that two-dimensionally divides the phosphor sheet on its plane to give plural small rectangular sections, and stimulable phosphor-incorporated areas which are rectangularly sectioned with the grid partition and which have a reflectance at the wavelength of the stimulating rays which differs from that of the grid partition. 2. The stimulable phosphor sheet of  claim 1 , which has a support provided on one surface side thereof and a transparent protective film provided on the other surface side. claim 1 3. The stimulable phosphor sheet of  claim 1 , wherein each of the stimulable phosphor-containing grid partition and the stimulable phosphor-incorporated area comprises stimulable phosphor particles and a binder. claim 1 4. A process for producing a stimulable phosphor sheet, which comprises the steps of: (i) producing plural stimulable phosphor films A and plural stimulable phosphor films B having a reflectance at the wavelength of the stimulating rays which differs from that of the films A;  (ii) forming a multi-layered composition block in which the stimulable phosphor films A and the stimulable phosphor films B are alternately piled up under the condition that neighboring phosphor films A and B would be placed in close contact with each other;  (iii) repeatedly slicing the multi-layered composition block in the direction perpendicular to the plane of the piled films, to prepare plural striped phosphor films in which strips of the stimulable phosphor films A and B are alternately arranged;  (iv) forming another multi-layered composition block in which the striped phosphor films and the stimulable phosphor films B are alternately piled up under the condition that neighboring striped film and stimulable phosphor film B would be placed in close contact with each other; and  (v) slicing repeatedly the multi-layered composition block formed in the step (iv) in the direction perpendicular to the plane of the piled films, so as to give a stimulable phosphor sheet which comprises a stimulable phosphor-containing grid partition two-dimensionally dividing the phosphor sheet on its plane to give plural small rectangular sections,.and stimulable phosphor-incorporated areas which are rectangularly sectioned with the grid partition and which have a reflectance at the wavelength of the stimulating rays which differs from that of the grid partition. 5. The process of  claim 4 , wherein each of the stimulable phosphor films A and B comprises stimulable phosphor particles and a binder. claim 4 6. The process of  claim 4 , wherein the multi-layered composition block of the step (ii) is prepared by alternately piling up the stimulable phosphor films A and the stimulable phosphor films B to form a multi-layered composition, and heating the composition under pressure. claim 4 7. The process of  claim 4 , wherein the multi-layered composition block of the step (iv) is prepared by alternately piling up the striped phosphor films and the stimulable phosphor films B to form a multi-layered composition, and heating the composition under pressure. claim 4 8. A stimulable phosphor sheet for a radiation image recording and reproducing method comprising the steps of recording a radiation image as a latent image, irradiating the latent image with stimulating rays to release stimulated emission, and electrically processing the emission to reproduce the radiation image, comprising a grid partition that contains a phosphor absorbing the radiation and emitting light in a UV or visible wavelength region and two-dimensionally divides the phosphor sheet on its plane to give plural small rectangular sections, and stimulable phosphor-incorporated areas which are rectangularly sectioned with the grid partition and which have a reflection property differing from that of the grid partition at the wavelength of the stimulating rays. 9. The stimulable phosphor sheet of  claim 8 , which has a support provided on one surface side thereof and a transparent protective film provided on the other surface side. claim 8 10. The stimulable phosphor sheet of  claim 8 , wherein the grid partition comprises phosphor particles absorbing the radiation and emitting light in a UV or visible wavelength region and a binder, and the stimulable phosphor-incorporated area comprises stimulable phosphor particles and a binder. claim 8 11. A process for producing a stimulable phosphor sheet, comprising the steps of: (i) producing plural stimulable phosphor films A and plural phosphor films B which contain a phosphor absorbing the radiation and emitting light in a UV or visible wavelength region and which have a reflectance differing from that of the films A at the wavelength of the stimulating rays;  (ii) forming a multi-layered composition block in which the stimulable phosphor films A and the phosphor films B are alternately piled up under the condition that neighboring phosphor films A and B would be placed in close contact with each other;  (iii) repeatedly slicing the multi-layered composition block in the direction perpendicular to the plane of the piled films, to prepare plural striped phosphor films in which strips of the phosphor films A and B are alternately arranged;  (iv) forming another multi-layered composition block in which the striped phosphor films and the phosphor films B are alternately piled up under the condition that neighboring striped film and phosphor film B would be placed in close contact with each other; and  (v) slicing repeatedly the multi-layered composition block formed in the step (iv) in the direction perpendicular to the plane of the piled films, so as to give a stimulable phosphor sheet which comprises a UV or visible light-emitting phosphor-containing grid partition two-dimensionally dividing the phosphor sheet on its plane to give plural small rectangular sections, and stimulable phosphor-incorporated areas which are rectangularly sectioned with the grid partition and which have a reflectance at the wavelength of the stimulating rays which differs from that of the grid partition. 12. The process of  claim 11 , wherein the stimulable phosphor-incorporated areas contain stimulable phosphor particles and a binder, and the phosphor-containing grid partition contains a binder and phosphor particles absorbing the radiation and emitting light in a UV or visible wavelength region. claim 11 13. The process of  claim 11 , wherein the multi-layered composition block of the step (ii) is prepared by alternately piling up the stimulable phosphor films A and the phosphor films B to form a multi-layered composition, and heating the composition under pressure. claim 11 14. The process of  claim 11 , wherein the multi-layered composition block of the step (iv) is prepared by alternately piling up the striped phosphor films and the phosphor films B to form a multi-layered composition, and heating the composition under pressure. claim 11 15. A process for producing a stimulable phosphor sheet, comprising the steps of: (i) producing plural stimulable phosphor films A and plural reflective material films B;  (ii) forming a multi-layered composition block in which the stimulable phosphor films A and the reflective material films B are alternately piled up under the condition that neighboring films A and B would be placed in close contact with each other;  (iii) repeatedly slicing the multi-layered composition block in the direction perpendicular to the plane of the piled films, to prepare plural striped phosphor films in which strips of the films A and B are alternately arranged;  (iv) forming another multi-layered composition block in which the striped phosphor films and the reflective material films B are alternately piled up under the condition that neighboring striped film and film B would be placed in close contact with each other; and  (v) slicing repeatedly the multi-layered composition block formed in the step (iv) in the direction perpendicular to the plane of the piled films, so as to give a stimulable phosphor sheet which comprises a reflective material-containing grid partition two-dimensionally dividing the phosphor sheet on its plane to give plural small rectangular sections, and stimulable phosphor-incorporated areas which are rectangularly sectioned with the grid partition. 16. The process of  claim 15 , wherein the stimulable phosphor-incorporated areas contain stimulable phosphor particles-and a binder, and the reflective material-containing grid partition contains a binder and reflective material particles. claim 15 17. The process of  claim 15 , wherein the multi-layered composition block of the step (ii) is prepared by alternately piling up the stimulable phosphor films A and the reflective material films B to form a multi-layered composition, and heating the composition under pressure. claim 15 18. The process of  claim 15 , wherein the multi-layered composition block of the step (iv) is prepared by alternately piling up the striped phosphor films and the reflective material films B to form a multi-layered composition, and heating the composition under pressure. claim 15