Self-masking X-ray viewing apparatus

Claim 2

Apparatus for holding and illuminating an X-ray film comprising a light diffusing viewing screen having front and rear faces, said viewing screen being provided with a plurality of spaced air inlet holes extending therethrough between the front and rear faces, a grid alongside the rear face forming a network of light-confining and air-conducting chambers one in communication with each air inlet hole, suction means connected to the chambers to cause a flow of air through each air inlet hole and communicating chamber, lighting means near the grid for directing light through the chambers to the viewing screen, and shutter means associated with each chamber having means thereon which cooperates with air flowing in said chamber so that said shutter is normally supported in a light-blocking position, said X-ray film when placed on the front face of the viewing screen to be held thereon by atmospheric pressure blocking those air inlet holes within the borders of said film whereby only the shutter means in the chambers behind the blocked air inlet holes move to light-admitting positions.

Claim 3

Apparatus as claimed in claim 1, and including control means for the vacuum means, said control means allowing the air flow through the chamber to be reduced to a value whereby all shutter means remain in light-admitting positions.

Claim 4

Apparatus as claimed in claim 1, in which said shutter means each comprises a flap freely mounted in a chamber, said flap having a rear edge weighted to act as a pivot point and an upturned front edge projecting over an adjacent air inlet hole when the shutter means is in the light-admitting position.

Claim 5

Apparatus as claimed in claim 1, in which said shutter means each comprises a flap freely mounted in each chamber, said flap having a rear edge acting as a pivot point and a curved transparent flange projecting above said rear edge, said transparent flange being disposed in the path of air flowing through the chamber whereby to initiate pivotal movement of the flap to dispose the shutter means in light-blocking position.

Claim 6

Apparatus as claimed in claim 1, in which said shutter means each comprises a flap freely mounted in a chamber, said flap having a rear edge weighted to act as a pivot point and a front edge, said air inlet holes each communicating with their chambers through an opening formed in a wall of said chamber beneath the front edge of the flap, and a window extending across each chamber near the front edge of the flap to separate the opening of that chamber from the air inlet hole of an adjacent chamber.

Claim 7

Apparatus for holding and illuminating an X-ray film comprising a cabinet, a light diffusing viewing screen forming a wall of the cabinet and having front and rear faces, said viewing screen being provided with a plurality of spaced air inlet holes extending therethrough between the front and rear faces, a grid alongside the rear face forming a network of light-confining and air-conducting chambers one in communication with each air inlet hole, suction means connected to the cabinet to partially evacuate the interior thereof and cause a flow of air through each air inlet hole and communicating chamber, light means within the cabinet behind the grid for directing light through the chambers to the viewing screen, and shutter means associated with each chamber having means thereon which cooperates with air flowing in said chamber so that said shutter is normally supported in a light-blocking position, said X-ray film when placed on the front face of the viewing screen to be held thereon by atmospheric pressure blocking those air inlet holes within the borders of said film whereby only the shutter means in the chambers behind the blocked air inlet holes move to light-admitting position, and control means for regulating the vacuum means.

Claim 8

Apparatus for holding and illuminating an X-ray film comprising a cabinet, a light diffusing viewing screen forming a wall of the cabinet and having front and rear faces, said viewing screen being provided with a plurality of spaced air inlet holes extending therethrough between the front and rear faces, a grid alongside the rear face forming a network of light-confining and air-conducting chambers one in communication with each air inlet hole, suction means connected to the cabinet to partially evacuate the interior thereof and cause a flow of air through each air inlet hole and communicating chamber, light means within the cabinet behind the grid for directing light through the chambers to the viewing screen, and shutter means associated with each chamber having means thereon which cooperates with air flowing in said chamber so that said shutter is normally supported in a light-blocking position, said X-ray film when placed on the front face of the viewing screen to be held thereon by atmospheric pressure blocking those air inlet holes within the borders of said film whereby only the shutter means in the chambers behind the blocked air inlet holes move to light-admitting position, and control means for regulating the vacuum means.