Apparatus having "small" and "large" x-ray scintillation images each approximately at full camera resolution

Abstract

Unused camera pixel locations are recovered when shifting from photographing an x-ray scintillation image of a larger subject to that of a substantially smaller one by using a suitably shorter optical path combined with appropriate changes in focus. The optical path for large subjects involves a first mirror followed by a second mirror. The camera receives light from the second mirror, and is in a fixed and unchanging physical relationship to that second mirror, forming a unitary mirror-camera assembly. To shorten the optical path that unitary assembly is rotated about an axis from a position where it was in the optical path downstream from the first mirror to one where the second mirror is interposed between the scintillation screen and the first mirror, and also such that the camera looks in a different direction along the shortened optical path length. Focus adjustment to accommodate the different optical paths may be accomplished by changing the spacing of elements internal to the lens, or, the entire lens assembly can be moved a bit closer to or further away from the camera body. The scintillation image may be replaced with a glass plate carrying a document illuminated from within a housing carrying the unitary mirror-camera assembly.

1 . Scintillation apparatus comprising:
 a planar scintillation screen;   a planar first mirror reflecting larger scintillation images along a first direction that leads away from the scintillation screen;   a unitary assembly, comprising a planar second mirror and a camera, that when disposed in a first location re-reflects into the camera with the second mirror reflected larger scintillation images visible along the first direction, and that when disposed in a second location intercepts with the second mirror smaller scintillation images before they reach the first mirror; and   an axle having an axis of rotation for the unitary assembly, the axis of rotation being parallel to the intersection of the plane of the scintillation screen with the plane of the first mirror, the first and second locations obtained by rotation of the unitary assembly about the axis of rotation.   
     
     
         2 . Apparatus as in  claim 1  wherein a line formed by intersecting the plane of the second mirror with that of the first mirror is parallel to the intersection of the plane of the scintillation screen with the plane of the first mirror. 
     
     
         3 . Apparatus as in  claim 1  wherein the camera comprises a digital camera. 
     
     
         4 . Apparatus as in  claim 1  wherein the camera further comprises a lens that is focused in response to electrical signals originating with controls associated with the camera. 
     
     
         5 . Apparatus as in  claim 1  wherein the camera further comprises a lens assembly and a camera body, and the lens assembly is focused by sliding it toward the camera body when the unitary assembly is disposed in the first location. 
     
     
         6 . Apparatus as in  claim 1  wherein the camera further comprises a lens assembly and a camera body, and the lens assembly is focused by sliding it away from the camera body when the unitary assembly is disposed in the second location. 
     
     
         7 . Apparatus as in  claim 1  wherein the camera further comprises a lens assembly, a focus push rod and a camera body, and the lens assembly is focused by sliding it's location relative to the camera body through coupling to the focus push rod and by moving the focus push rod in accordance with whether the unitary assembly is disposed in the first location or disposed in the second location. 
     
     
         8 . Apparatus as in  claim 1  wherein the scintillation apparatus further comprises a radius arm coupled at a first end to the axle and a scintillation imaging area push rod coupled to a second end of the radius arm, unitary assembly rotating between the first and second locations when the scintillation imaging area push rod is displaced to occupy respective first and second positions. 
     
     
         9 . Apparatus as in  claim 8  wherein the camera further comprises a lens assembly, a focus push rod coupled to the scintillation imaging area push rod and a camera body, and the lens assembly is focused by sliding it's location relative to the camera body through coupling to the focus push rod and by moving the focus push rod in accordance with whether the scintillation imaging area push rod occupies it's first or second position. 
     
     
         10 . Scintillation apparatus as in  claim 1  further comprising a table, and wherein the planar scintillation screen, the planar first mirror, the unitary assembly and the axle comprise a camera housing, and the table and camera housing have respective cooperating tracks and rollers that allow the camera housing to traverse along a length of the table.