Patent Number: 
Section: claims

1. An apparatus for obtaining a long-length x-ray image of a subject, comprising:an x-ray source;a first sensor configured to sense x-ray transmission from the x-ray source and to generate a first signal that indicates termination of x-ray emission from the x-ray source;a digital radiography detector that is energizable to generate image data after receiving x-ray emission from the x-ray source;a detector transport apparatus actuable in response to the first signal to translate the digital radiography detector from at least a first detector position to a second detector position for generating image data at each detector position;a processor in communication with the digital radiography detector for obtaining the image data of the subject that is generated from the detector;a movable mask operatively associated with the x-ray source and providing an aperture that directs x-rays from the x-ray source toward the subject for capturing a plurality of separate images of the subject on the digital radiography detector;a second sensor operatively associated with the movable mask to produce a second signal in response to detecting X-ray emission from the source; anda mask translation control responsive to the second signal for moving the movable mask from at least a first mask position to a second mask position for exposing an area of the subject. 2. The apparatus of claim 1 wherein the movable mask is coupled to a collimator of the x-ray source. 3. The apparatus of claim 1 wherein the movable mask is removably or permanently coupled to the x-ray source. 4. The apparatus of claim 1 wherein the detector transport apparatus comprises one or more of a spring, a servo motor, and a solenoid. 5. The apparatus of claim 1 wherein the mask translation control further comprises one or more of a spring, a servo motor, and a solenoid. 6. The apparatus of claim 1 wherein the mask translation control uses gravity for moving the mask. 7. The apparatus of claim 1 wherein the first sensor is an audio sensor or a photosensor. 8. The apparatus of claim 1 wherein the first sensor or the second sensor is an audio sensor or a photosensor. 9. The apparatus of claim 1 wherein the detector transport apparatus actuable in response to the first signal to translate the digital radiography detector and the mask translation control responsive to the second signal for moving the mask operate independently from each other. 10. The apparatus of claim 1 where a single controller does not control both the detector transport apparatus and the mask translation control. 11. The apparatus of claim 1 further comprising an indicator that is actuable to indicate that the digital radiography detector is ready for exposure. 12. The apparatus of claim 1 further comprising an indicator that is actuable to indicate that the digital radiography detector is ready for translation to the second detector position. 13. A method for obtaining a long-length x-ray image of a subject, comprising:positioning a digital radiography detector at a first detector position relative to the subject;positioning a movable mask to a first mask position relative to an x-ray source that directs exposure energy onto the digital radiography detector at the first detector position;energizing the x-ray source to expose the subject at the first detector position;obtaining a first signal from a first sensor that indicates termination of x-ray emission from the x-ray source;obtaining image data from the digital radiography detector at the first detector position;obtaining a second signal from a second sensor that indicates termination of x-ray emission from the x-ray source;asynchronously actuating a detector transport apparatus to translate the digital radiography detector from the first detector position to a second detector position for generating image data responsive to the first signal and a mask transport apparatus to translate the movable mask to a second mask position that directs exposure energy onto the digital radiography detector responsive to the second signal;energizing the x-ray source to expose the subject at the second detector position;obtaining a third signal from the first sensor that indicates termination of x-ray emission from the x-ray source;obtaining image data from the digital radiography detector at the second detector position; andcombining the image data from at least the first and second detector positions to form the long-length x-ray image. 14. The method of claim 13 further comprising manually setting up at least the first and second detector positions and storing the first and second positions in a memory. 15. The method of claim 13 wherein actuating the detector transport apparatus comprises energizing a motor or a solenoid. 16. The method of claim 13 wherein actuating the mask transport apparatus comprises energizing a motor or a solenoid. 17. An apparatus for obtaining a long-length x-ray image of a subject, comprising:an x-ray source;a first sensor that generates a first signal that indicates x-ray emission from the x-ray source;a digital radiography detector that is energizable to generate image data after receiving x-ray emission from the x-ray source;a detector transport apparatus actuable in accordance with the first signal to translate the digital radiography detector from at least a first detector position to a second detector position for generating image data at each detector position;a processor in communication with the digital radiography detector for obtaining the image data of the subject generated from the detector;a movable mask operatively associated with the x-ray source and providing an aperture that directs x-rays from the x-ray source toward the subject for capturing a plurality of separate images of the subject on the digital radiography detector;a second sensor operatively associated with the movable mask for producing a second signal in response to termination of X-ray emission from the source; anda mask translation control responsive to the second signal for moving the mask from at least a first mask position to a second mask position for exposing an area of the subject. 18. The apparatus of claim 17 wherein the first or second sensor is an audio sensor or a photosensor. 19. The apparatus of claim 17 wherein the detector transport apparatus comprises one or more of a spring, a servo motor, and a solenoid.