Projection apparatus for use in article inspection

Claim 1

IN INSPECTING APPARATUS OF THE KIND WHICH INCLUDES A LIGHT-TIGHT CABINET HAVING AN APERTURE IN ITS WALL IN WHICH IS FITTED A TRANSLUCENT SCREEN, A REFLECTOR DEVICE OPERATIVE TO PROJECT AN IMAGE OF AN OBJECT INTO THE SPACE WITHIN THE CABINET, MIRROR MEANS WITHIN THE CABINET FOR REFLECTING SAID IMAGE ONTO THE INNER SURFACE OF THE SCREEN, SAID REFLECTOR DEVICE COMPRISING A HOLLOW CASING HAVING WITHIN IT A SUPPORT FOR THE OBJECT WHOSE IMAGE IS TO BE PROJECTED ONTO THE SCREEN AND A LIGHT SOURCE FOR ILLUMINATING THE OBJECT, THE CASING HAVING AN APERTURE PROVIDED WITH A LENS WHEREBY AN IMAGE OF THE OBJECT IS PROJECTED OUTWARDLY FROM THE CASING ONTO SAID MIRROR MEANS, THE INNER SURFACE OF SAID CASING BEING LIGHT-REFLECTING, THE CASING COMPRISING A MID-PORTION WHOSE CONCAVE INNER SURFACE IS THAT OF THE MID-SEGMENT OF AN ELLIPSOID OF REVOLUTION WHOSE ENDS ARE DEFINED BY PARALLEL PLANES PERPENDICULAR TO ITS MAJOR AXIS AND PASSING THROUGH ITS RESPECTIVE FOCI, THE OPPOSITE END PORTIONS OF THE CASING HAVING CONCAVE INNER SURFACES WHICH ARE SEGMENTS OF PARABALOIDS OF REVOLUTION WHOSE FOCI COINCIDE WITH THE RESPECTIVE FOCI OF THE ELLIPSOID, THE OBJECT BEING SUPPORTED AT ONE OF SAID FOCI AND THE LIGHT SOURCE BEING LOCATED AT THE OTHER OF SAID FOCI.