Storage phosphor cassette

An x-ray cassette having increased durability. The x-ray cassette comprises a shell and a storage phosphor assembly. The shell comprises an upper and lower panel, a first and second side member, and a front end member, with the first and second side members and front end member joining the upper and lower panels to define a cavity having an open end. The storage phosphor assembly comprises an insert plate having a first and second side, a back end member having two ends, and a first and second edge insert. The storage phosphor assembly is adapted to be removably contained within the shell such that the back end member closes off the open end of the shell. The first and second edge inserts are affixed to the first and second sides, respectively. The back end member has at each end an extension extending in a direction parallel to the length of the back end member to interlock the back end member with the first and second edge inserts such that the force of an impact to the cassette is transferred to the back end member rather than to the insert plate to avoid buckling thereof and to avoid separation of the back end member from the insert plate.

FIELD OF THE INVENTION

The present invention relates generally to cassettes for photographic elements, and more particularly, to an x-ray cassette used in computed radiography.

BACKGROUND OF THE INVENTION

In the field of computed radiography, a photographic element has an image formed thereon by x-rays. The photographic element is subsequently provided to a reader wherein the element is stimulated to emit a radiation pattern that is indicative of the image formed by the x-rays. Typically, storage phosphors are used to capture radiographic images from incident x-rays. Most radiographic procedures are carried out within normal room lighting conditions, accordingly, a primary requirement for any computed radiography x-ray cassette is to shield the storage phosphor from exposure by ambient light.

Cassettes of the kind used in computed radiography may comprise a container having an upper and lower parts that are hinged together so that they can be opened for insertion of a flexible film sheet or a rigid film plate comprising the photographic element. The cassette is closed and latched so that the cassette with the element therein can be used with an x-ray apparatus to produce an image on the photographic element. Then, the cassette is taken to a reader where the cassette is opened and the photographic element extracted by suitable feeders, such as a suction feeding device. The photographic element separates from the cassette, and is transported through the reader where it is stimulated to emit a radiation pattern which is captured for storage and use. The radiation pattern is subsequently erased from the photographic element before being returned to the cassette for re-use.

While such cassettes may have achieved certain degrees of success in their particular applications, cassettes are susceptible to various types of damage when dropped or roughly handled. Accordingly, it is desirable to increase the durability of the cassette while minimizing cost and weight, and preserving the same basic nature of design.

Accordingly, a need continues to exist for a cassette which is durable and reduces its susceptibility to damage when dropped or roughly handled, and the same basic nature of design is preserved.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a cassette which has increased durability, and is resistant to damage when dropped or roughly handled.

This object is given only by way of illustrative example. Thus, other desirable objectives and advantages inherently achieved by the disclosed invention may occur or become apparent to those skilled in the art. The invention is defined by the appended claims.

According to one aspect of the invention, there is provided a x-ray cassette comprising a shell and a storage phosphor assembly. The shell comprises an upper and lower panel, a first and second side member, and a front end member, with the first and second side members and front end member joining the upper and lower panels to define a cavity having an open end. The storage phosphor assembly comprises an insert plate having a first and second side, a back end member having two ends, and a first and second edge insert. The storage phosphor assembly is adapted to be removably contained within the shell such that the back end member closes off the open end of the shell. The first and second edge inserts are affixed to the first and second sides, respectively. The back end member has at each end an extension extending in a direction parallel to the length of the back end member to interlock the back end member with the first and second edge inserts such that the force of an impact to the cassette is transferred to the back end member rather than to the insert plate to avoid buckling thereof.

The present invention provides a cassette which has increased durability and reduced susceptibility to damage when dropped or roughly handled.

DETAILED DESCRIPTION OF THE INVENTION

The following is a detailed description of the preferred embodiments of the invention, reference being made to the drawings in which the same reference numerals identify the same elements of structure in each of the several figures.

FIGS. 1-4 show a storage phosphor cassette 10 in accordance with the present invention. Cassette 10 includes a shell 12 comprising an upper panel 14 , a lower panel 16 , a first side member 18 , a second side member 20 , and a front end member 22 . Upper and lower panels 14 , 16 are preferably rectangular in shape. First side member 18 , second side member 20 , and front end member 22 join upper and lower panels 14 , 16 to form a five-sided cavity having an open end 24 .

Cassette 10 further includes a storage phosphor assembly 26 having a front edge 27 , a back end member 28 , an insert plate 30 having an upper face and being cantilevered from back end member 28 , and a storage phosphor 32 disposed on the upper face of insert plate 30 . A front edge of insert plate 30 includes corners 68 , 70 , which are preferably rounded. Back end member 28 includes apertures 29 , 31 for access to the interior of back end member 28 to latch and unlatch a latch bar 50 slidably mounted therein.

Storage phosphor assembly 26 is removably contained within the cavity of shell 12 such that back end member 28 of storage phosphor assembly 26 closes off open end 24 of shell 12 , thereby providing a light-tight enclosure for storage phosphor 32 .

Back end member 28 of storage phosphor assembly 26 includes end portions 64 , 66 . First and second side members 18 , 20 include a corner structure 60 , 62 , respectively, which respectively engage end portions 64 , 66 . Corner structures 60 , 62 can be integral with first and second side members 18 , 20 , or as illustrated, can be separate corner pieces which are secured to first and second side members 18 , 20 . End portions 64 , 66 and respective corner structures 60 , 62 have complimentary, interlocking configurations, such that, should cassette 10 be dropped and a force exerted on either corner structure 60 , 62 , the force is transferred to storage phosphor assembly 26 , forcing assembly 26 into shell 12 . Corner structure 62 engaged with end portion 66 is further illustrated in FIGS. 5-6 .

Referring now to FIGS. 7-10 , to minimize damage to insert plate 30 should cassette 10 be dropped, insert plate 30 is comprised of a lightweight rigid structure including an aluminum honeycomb core 71 and outer aluminum skins 72 , 74 . The edge of honeycomb core 71 is milled out (recessed) around the entire perimeter to create a cavity. As best illustrated in FIG. 7 , edge inserts 76 , 78 , 80 are each glued into a side of the cavity formed in the honeycomb structure. Back end member 28 is inserted to a fourth side of the cavity formed in the honeycomb structure. One end of edge insert 76 interlocks with back end member 28 by means of a connector 90 which can be, for example, a key or leg. Similarly, one end of edge insert 80 interlocks with back end member 28 by means of a connector 92 which can be, for example, key or leg. As illustrated in FIG. 7 , connectors 90 , 92 are each shown as a leg of back end member 28 extending into edge inserts 76 , 80 in a direction parallel to the length of back end member 28 , which is transverse to the length of edge inserts 76 , 80 , respectively. Edge inserts 76 , 80 comprise a complimentary recess to mate with connectors 90 , 92 . The interlocking arrangement of edge inserts 76 , 80 with back end member 28 transfers a force from a side impact to cassette 10 to back end member 28 rather than buckling outer aluminum skins 72 , 74 . This interlocking arrangement of edge inserts 76 , 80 also serves to capture back end member 28 so as to prevent it from being separated or loosened from honeycomb core 71 during rough handling, or from a force which attempts to dislocate it.

Referring now to FIGS. 11-12 , edge inserts 76 , 80 may optionally comprise a plurality of shallow slots or channels 93 disposed on at least one of its surfaces. Such channels 93 promote adhesion of the edge inserts with insert plate 30 since they provide additional surface area for the glue to migrate and adhere rather than being directed to the cells of the honeycomb. As illustrated, channels 93 form an angle relative to an edge of edge inserts 76 , 80 . A cross-hatch pattern might also be employed.

As illustrated in FIGS. 11-13 , back end member 28 may also optionally comprise channels 93 , with channels 93 being angled relative to an edge of back end member 28 .

Preferably, edge inserts 76 , 80 extend slightly beyond the perimeter of outer aluminum skins 72 , 74 (as shown in FIG. 3 at 94 , 96 , respectively) thereby creating a shock absorption system to absorb and distribute forces on insert plate 30 . If edge inserts 76 , 80 extend beyond the perimeter of outer aluminum skins 72 , 74 , then preferably channels 93 are disposed on that portion of edge inserts 76 , 80 which do not extend beyond the perimeter, but rather, are disposed on that portion of edge inserts 76 , 80 internal to honeycomb core 71 .

Preferably, edge inserts 76 , 80 are of aluminum, edge insert 78 is of a polymeric material, and back end member 28 is of an aluminum material.