Patent Number: 
Section: claims

1. A radiation image read-out method, comprising:using a stimulable phosphor sheet;projecting stimulating light onto the stimulable phosphor sheet from the protective layer side; anddetecting stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light by imaging the stimulated emission on a line sensor by an imaging lens from the protective layer side while moving the stimulable phosphor sheet relatively to the line sensor in a direction intersecting the direction in which the line sensor extends,wherein the stimulable phosphor sheet comprises a stimulable phosphor layer and a protective layer, the protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer, andwherein the stimulable phosphor layer is in contact with the protective layer at a plurality of discontinuous contact areas. 2. A radiation image read-out apparatus, comprising:a stimulable phosphor sheet;a stimulating light projecting means which projects stimulating light onto the stimulable phosphor sheet from the protective layer side;a detecting means which detects stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light by imaging the stimulated emission on a line sensor by an imaging lens from the protective layer side; anda conveyor means which moves the stimulable phosphor sheet relatively to the detecting means in a direction intersecting the direction in which the line sensor extends,wherein the stimulable phosphor sheet comprises a stimulable phosphor layer and a protective layer, the protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer, andwherein the stimulable phosphor layer is in contact with the protective layer at a plurality of discontinuous contact areas. 3. A radiation image read-out apparatus as defined in claim 2 in which the conveyor means conveys the stimulable phosphor sheet relatively to the detecting means so that the surface profile of the surface of the stimulable phosphor layer facing the protective layer is positioned within the range of the focal depth of the imaging lens. 4. A stimulable phosphor sheet comprising a stimulable phosphor layer and a protective layer, stimulating light being projected onto the stimulable phosphor layer from the protective layer side and stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light being detected by a line sensor through an imaging lens from the protective layer side, wherein the improvement comprises thatthe protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer, andwherein the stimulable phosphor layer is in contact with the protective layer at a plurality of discontinuous contact areas. 5. A stimulable phosphor sheet as defined in claim 4 in which the protective layer is in the range of not smaller than 0.2 mm and not larger than 10 mm in thickness. 6. A stimulable phosphor sheet as defined in claim 4 comprising:an elastic member,wherein the elastic member presses the stimulable phosphor layer toward the protective layer from the side opposite to the protective layer so that the surface of the stimulable phosphor layer facing the protective layer is brought into contact with the protective layer. 7. A stimulable phosphor sheet as defined in claim 4 in which the surface of the stimulable phosphor layer facing the protective layer is bonded to the surface of the protective layer facing the stimulable phosphor layer by contact bonding under heat. 8. The stimulable phosphor sheet of claim 4 wherein the stimulable phosphor layer is bonded to the protective layer. 9. The stimulable phosphor sheet of claim 4, comprising:an adhesive tape,wherein the adhesive tape attaches the stimulable phosphor layer to the protective layer so that their respective surfaces are in contact with the other. 10. A stimulable phosphor sheet comprising a stimulable phosphor layer and a protective layer, stimulating light being projected onto the stimulable phosphor layer from the protective layer side and stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light being detected by a line sensor through an imaging lens from the protective layer side, wherein the improvement comprises thatthe protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer, andwherein the surface of the stimulable phosphor layer facing the protective layer is within the range of ±100 μm in surface profile error. 11. A stimulable phosphor sheet comprising a stimulable phosphor layer and a protective layer, stimulating light being projected onto the stimulable phosphor layer from the protective layer side and stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light being detected by a line sensor through an imaging lens from the protective layer side, wherein the improvement comprises thatthe protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer, andwherein the surface of the stimulable phosphor layer facing the protective layer be in the range of not smaller than 0.05 μm and not larger than 5 μm in center line surface roughness. 12. A stimulable phosphor sheet comprising a stimulable phosphor layer and a protective layer, stimulating light being projected onto the stimulable phosphor layer from the protective layer side and stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light being detected by a line sensor through an imaging lens from the protective layer side, wherein the improvement comprises thatthe protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer,wherein the stimulable phosphor layer is in contact with the protective layer by way of filler with a void formed between the stimulable phosphor layer and the protective layer, andwherein the filler is positioned on a coating layer formed on the stimulable phosphor layer and/or the protective layer. 13. A stimulable phosphor sheet as defined in claim 12 in which the thickness of the coating layer is in the range of not smaller than 0.1 μm and not larger than 20 μm, and the particle diameter of the filler is in the range of not smaller than 0.2 μm and not larger than 50 μm. 14. A radiation image read-out method in which a stimulable phosphor sheet comprising a stimulable phosphor layer in contact with a protective layer which is rigid and transparent is used, stimulating light is projected onto the stimulable phosphor sheet from the protective layer side, stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light is detected by imaging the stimulated emission on a line sensor by an imaging lens from the protective layer side while moving the stimulable phosphor sheet relatively to the line sensor in a direction intersecting the direction in which the line sensor extends, and further comprising:providing the stimulable phosphor layer and the protective layer in direct physical contact with the stimulable phosphor layer at a plurality of locations,wherein the phosphor layer and the protective layer are separated by an air cushion at locations at which both layers are not in direct physical contact with each other. 15. A radiation image read-out apparatus comprising a stimulable phosphor sheet having a stimulable phosphor layer in contact with a protective layer which is rigid and transparent, a stimulating light projecting means which projects stimulating light onto the stimulable phosphor sheet from the protective layer side, a detecting means which detects stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light by imaging the stimulated emission on a line sensor by an imaging lens from the protective layer side, and a conveyor means which moves the stimulable phosphor sheet relatively to the detecting means in a direction intersecting the direction in which the line sensor extends,wherein the stimulable phosphor layer and the protective layer are in direct physical contact with the stimulable phosphor layer at a plurality of locations, andwherein the phosphor layer and the protective layer are separated by an air cushion at locations at which both layers are not in direct physical contact with each other. 16. A stimulable phosphor sheet comprising a stimulable phosphor layer and a protective layer, stimulating light being projected onto the stimulable phosphor layer from the protective layer side and stimulated emission emitted from the stimulable phosphor layer upon exposure to the stimulating light being detected by a line sensor through an imaging lens from the protective layer side, wherein the improvement comprises thatthe protective layer is formed of a rigid transparent material and the stimulable phosphor layer is in contact with the protective layer,wherein the stimulable phosphor layer and the protective layer are in direct physical contact with the stimulable phosphor layer at a plurality of locations, andwherein the phosphor layer and the protective layer are separated by an air cushion at locations at which both layers are not in direct physical contact with each other.