X-ray absorbing wedge for improving soft tissue outline

Claim 2

An X-ray cassette for use in dental and medical X-ray equipment, said cassette comprising: a film-receiving compartment, a thin, plate-like member of X-ray absoring material, and means mounting said member in ray-filtering relationship to X-ray radiation incident on a portion of a film in said compartment, said member extending partially across the cassette to a featheredge of the member beyond which the radiation will be unfiltered, said featheredge being sufficiently thin to prevent a visible line of demarcation from appearing between the filtered and unfiltered areas of a resulting radiograph, and said member being tapered toward said featheredge to present absorptive material of progressively increased thickness away from said featheredge to thereby provide progressively increased soft tissue resolution away from said featheredge in said portion of a film

Claim 3

The cassette as claimed in claim 1, wherein said member extends from a margin of the cassette to said featheredge.

Claim 4

The cassette as claimed in claim 1, wherein at least a part of said member is wedge-shaped in cross section and presents said featheredge.

Claim 5

The cassette as claimed in claim 1, wherein said material is an admixture of a particulate, highly absorptive substance dispersed in a solidified resin.

Claim 6

The cassette as claimed in claim 4, wherein said substance is lead oxide.

Claim 7

The cassette as claimed in claim 4, wherein said resin is present in said admixture in an amount equal to approximately 25 parts by weight, and said substance is lead oxide present in an amount in the range of from 25 to 100 parts by weight.

Claim 8

In an X-ray cassette used in dental and medical X-ray equipment, said cassette having a front, light-opaque plate, a rear access door, and a film-receiving compartment between said plate and said door, the improvement comprising a thin, plate-like member of X-ray absorbing material disposed between said front plate and said compartment, said member being in ray-filtering relationship to X-ray radiation incident on a portion of a film in said compartment and entending partially across the cassette to a featheredge of the member beyond which the radiation will be unfiltered, said featheredge being sufficiently thin to prevent a visible line of demarcation from appearing between the filtered and unfiltered areas of a resulting radiograph, said member being tapered toward said featheredge to present absorptive material of progressively increased thickness away from said featheredge to thereby provide progressively increased soft tissue resolution away from said featheredge in said portion of a film

Claim 9

In an X-ray cassette used in dental and medical X-ray equipment, said cassette having a front, light-opaque plate, a rear access door, and a film-receiving compartment between said plate and said door, the improvement comprising a thin, plate-like member of X-ray absorbing material disposed between said front plate and said compartment, said member being in ray-filtering relationship to X-ray radiation incident on a portion of a film in said compartment and entending partially across the cassette to a featheredge of the member beyond which the radiation will be unfiltered, said featheredge being sufficiently thin to prevent a visible line of demarcation from appearing between the filtered and unfiltered areas of a resulting radiograph, said member being tapered toward said featheredge to present absorptive material of progressively increased thickness away from said featheredge to thereby provide progressively increased soft tissue resolution away from said featheredge in said portion of a film

Claim 10

The improvement as claimed in claim 7, wherein said member extends from a margin of the cassette to said featheredge.

Claim 11

The improvement as claimed in claim 7, wherein at least a part of said member is wedge-shaped in cross section and presents said featheredge.

Claim 12

The improvement as claimed in claim 7, wherein said material is an admixture of a particulate, highly absorptive substance dispersed in a solidified resin.

Claim 13

The improvement as claimed in claim 10, wherein said substance is lead oxide.

Claim 14

The improvement as claimed in claim 10, wherein said resin is present in said admixture in an amount equal to approximately 25 parts by weight, and said substance is lead oxide present in an amount in the range of from 25 to 100 parts by weight.

Claim 15

The improvement as claimed in claim 7, wherein said cassette further has opposed, front and rear intensifying screens defining said compartment, said member being sandwiched between said front plate and said front intensifying screen.

Claim 16

The improvement as claimed in claim 7, wherein said member extends from a margin of the cassette to said featheredge, a part of said member spaced from said margin being wedge-shaped in cross section and presenting said featheredge.

Claim 17

The improvement as claimed in claim 14, wherein said front plate is provided with a visible line on its outer face marking the location of said wedge-shaped part within the cassette, whereby to aid in alignment of the patient with the cassette.