Patent Number: 
Section: claims

1. A system for phase stepping in phase contrast image acquisition, the device comprising:a phase contrast image acquisition apparatus including a radiation source; anda device comprising:a mobile grating spaced apart, in an optical axis direction of a radiation emitted from the radiation source, from the radiation source, wherein the mobile grating is movable along a linear direction different from the optical axis direction;a guide,wherein when the mobile grating is moving along the linear direction different from the optical axis direction, the guide is configured to guide the mobile grating between a first position and a second position and along the linear direction different from the optical axis direction, andwherein the first position is offset from the second position in the linear direction different from the optical axis direction;a restorer configured to apply a force to the mobile grating, the force being directed from the first position to the second position; anda lock configured to releasably lock the mobile grating in the first position. 2. The system according to claim 1, wherein the device further comprises:a position decoder configured to detect a position of the mobile grating along the guide and emit a trigger signal for a detector if the mobile grating passes predefined positions along the guiding element guide. 3. The system according to claim 1, wherein the mobile grating is configured to perform a continuous movement between the first position and the second position. 4. The system according to claim 1, wherein the device further comprises:a movement dampener configured to dampen a movement of the mobile grating between the first position and the second position. 5. The system according to claim 4, wherein the movement dampener is controllable. 6. The system according to claim 4, wherein the movement dampener applies at least an under critical dampening to the movement of the mobile grating. 7. The system according to claim 1, wherein the device further comprises:a mobile grating mover configured to move the mobile grating into the first position. 8. The system according to claim 1,wherein the phase contrast image acquisition apparatus comprisesat least one immobile grating; andwherein a movement of the mobile grating from the first position to the second position shifts the mobile grating relative to the at least one immobile grating. 9. The system according to claim 1, wherein the phase contrast image acquisition apparatus comprises:a detector that includesa photodiode array; anda scintillator;wherein the photodiode array matches the scintillator; andwherein the detector is configured to completely read out the photodiode array at least four times during a movement of the mobile grating between the first position and the second position. 10. A method for phase stepping in phase contrast image acquisition, the method comprising:locking a mobile grating in a first position with a lock,wherein the mobile grating and a radiation source are spaced apart from each other in an optical axis direction of a radiation emitted from the radiation source,wherein the mobile grating is movable between the first position and a second position and along a linear direction different from the optical axis direction of the radiation, andwherein the first position is offset from the second position in the linear direction different from the optical axis direction;applying a force on the mobile grating with a restorer, wherein the force is directed from the first position to the second position; andunlocking the lock such that the force moves the mobile grating into the second position. 11. The method according to claim 10, further comprising:reading out a detector on which X-ray radiation passing the mobile grating falls on.