Auto exposure measurement system for an x-ray digital image capturer

Abstract

A digital X-ray system for capturing high quality images by maximizing the collection of emitted light from an intensifying screen in response to X-ray impact. The digital X-ray system includes a housing having a fluorescent intensifying screen for receiving emitted X-rays, two reflectors for maximizing light collection and optimizing the light path from the intensifying screen, and a lens assembly. A CCD chip receives the light from the lens assembly, to provide a digital image for immediate on-board processing or post- processing by a computer. The housing is compact, and can be used as a direct replacement for traditional film cartridges without major modifications to the system. The lens assembly includes freeform matched lenses to remove optical distortions, and the housing includes a light sensor for providing exposure measurement and feedback. The system is designed to be quasi-monochromatic to maintain consistent image quality over the entire area of the intensifying screen.

1 . An auto exposure measurement system for an X-ray digital image capturer, the X-ray digital image capturer emitting light from a intensifying screen in response to received X-rays, the auto exposure measurement system comprising: 
 a light sensor for receiving the emitted light, the light sensor providing a signal corresponding to a level of received light;    a microprocessor storing a predetermined image exposure parameter for receiving the signal and for comparing the level of received light to the predetermined image exposure parameter; and,    a digital imaging device for receiving the emitted light, the digital imaging device being controllable by the microprocessor to generate digital image data when the level of the received light reaches the predetermined image exposure parameter.    
   
   
       2 . The auto exposure measurement system of  claim 1 , further including additional light sensors coupled to the microprocessor.  
   
   
       3 . The auto exposure measurement system of  claim 1 , wherein each light sensor includes a matched lens for receiving emitted light from specific areas of the intensifying screen.  
   
   
       4 . The auto exposure measurement system of  claim 1 , wherein the microprocessor stores a plurality of predetermined image exposure parameters, each corresponding to a desired image type.