Abstract:
According to the invention there is provided a relockable cartridge for photosensitive media, comprising (a) photo-inert and optically opaque media-receiving tray having a media access opening; (b) flexible, photo-inert and optically opaque cover for the media access opening; the cartridge including an openable and relockable magnetic seal between at least portions of the cover and tray, characterized in that one part of the magnetic seal is located on upperlips or projective guides of said tray and the other part of the magnetic seal consists of or is fixed to said cover.

Description:
This application claims benefit of Provisional Application 60/112,065 filed Dec. 14, 1998. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a solution for a method for packaging photographic films. More specifically the invention is related to a relockable casette or cartridge for medical imaging film. 
     BACKGROUND OF THE INVENTION 
     X-ray and other types of medical imaging photographic film are typically packaged in optically opaque (i.e. light-tight) and photo-inert containers such as cassettes, magazines, cartridges and bags. The film must be removed from these packages and loaded into the x-ray machine, camera or other imaging device under darkroom conditions, an inconvenient procedure. 
     U.S. Pat. No. 1,098,844 discloses a film package which can be loaded directly into a camera, thereby alleviating the need for a darkroom. However this package is relatively inefficient in design and requires manual manipulation to bring the film into exposure position. Said package is therefore incompatible with the automatic film handling mechanism of modern imaging systems. 
     U.S. Pat. No. 4,727,391 discloses a package for sheet film and a loading device for the package. The package includes a tray and a flexible cover peelably attached to the tray by an adhesive. After the package is loaded into a loading device of an image recorder, the cover is peeled off, enabling a delivery equipment to access the film. The adhesive layer has an edge portion inclined to the longitudinal direction of the tray so the cover can be peeled off easily. 
     Packages of the type shown in said patent contain many sheets of one specific type of film. However, depending on the nature of the image being exposed, it is often necessary to load different sizes and/or types of film into the photographic system. Any unexposed film remaining within a cartridge is therefore wasted if the cartridge must be removed from the photographic system so a new cartridge bearing a different type or size of film can be inserted. 
     “PCT/EP88/00166 discloses an automatic film loading device for sheet film cassettes. After a cassette is inserted into an unloading and reloading station in the device, the cassette is opened and the exposed sheet of film is seized, removed and transported to a developing apparatus. The cassette is then reloaded with a sheet of film from one of a plurality of supply magazines, each containing different sizes of film. The freshly loaded cartridge is then dispensed from the device for subsequent use. Although this automatic film loading device reduces the waste associated with the removal of unused film from an photographic system, it is a complicated and relatively expensive accessory for the photographic system.” 
     PCT/US92/00890 discloses a resealable cartridge for photosensitive media, comprising: (a) photo-inert and optically opaque media-receiving tray having a media access opening; (b) flexible, photo-inert and optically opaque cover for the media access opening; and (c)photo-inert and optically opaque seal between the tray and the cover, the seal including an openable and resealable adhesive seal between at least portions of the cover and tray. 
     It is evident that there is a continuing need for improved film handling systems for photographic photographic systems. In particular, there is a need for a device which conveniently enables different sizes and/or types of film to be inserted into and removed from a medical photographic system without resulting waste. The device must be relatively inexpensive to be commercially viable. 
     OBJECTS OF THE INVENTION 
     It is an object of the present invention to provide a material for a relockable cartridge for photosensitive material, which permits the use of different sizes and/or kinds of photographic film in an photographic system without waste. 
     Further objects of the present invention will be clear from the description hereafter. 
     SUMMARY OF THE INVENTION 
     According to the invention there is provided a relockable cartridge for photosensitive media, comprising (a) photo-inert and optically opaque media-receiving tray having a media access opening; (b) flexible, photo-inert and optically opaque cover for the media access opening; the cartridge including an openable and relockable magnetic seal between at least portions of the cover and tray, characterized in that one part of the magnetic seal is located on upperlips or projective guides of said tray and the other part of the magnetic seal consists of or is fixed to said cover. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a photographic system configured for use with a relockable film cartridge of the present invention. 
     FIG. 2 is a top view of a relockable film cartridge in accordance with the present invention, with a portion of the cover broken away. 
     FIG. 3 is a side view of the cartridge shown in FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is an illustration of a photographic system  10  which is configured to operate with a relockable photographic film cartridge in accordance with the present invention. In the embodiment shown, photographic system  10  includes a drawer  14  which is opened to provide access to a cartridge-receiving base  16  into which film cartridge  12  is loaded. A cartridge opening/closing mechanism  18  is also mounted to drawer  14 . After a film cartridge  12  has been loaded into base  16 , drawer  14  is closed to lock the cartridge within a light-tight compartment. Opening/closing mechanism  18  then opens cartridge  12  to permit access to sheets of film (not visible in FIG. 1) in the cartridge. Sheets of film are removed from the opened cartridge  12  and imaged by other subsystems (not shown) of photographic system  10 . The imaged film is temporary stored in a magazine (not shown) before being removed from photographic system  10  for subsequent processing. Alternatively, the imaged film can be automatically fed to a docked or attached film developer (not shown) for processing. 
     Opening/closing mechanism  18  is also actuated to close cartridge  12  before the cartridge can be removed from photographic system  10 . Since cartridge  12  is relockable, it can be removed from photographic system  10  before all the film within the cartridge has been exposed. Cartridges  12  with different sizes or types of film media can therefore be conveniently loaded into and removed from photographic system  10  as needed, without wasting any unused film remaining in the cartridge. 
     Relockable cartridge  12  can be described in greater detail with reference to FIGS. 2 and 3. As shown, cartridge  12  includes an optically opaque polymer film-receiving tray  20  and a flexible, optically opaque cover  22 . Cover  22  is relockable attached to tray  20  by magnetic sealing strips or segments  29 A, C-D. Tray  20  is preferably molded in one piece from a relatively inexpensive and photo-inert polyolefin material so that it is economically feasible to dispose of the cartridge following a single use. In one embodiment tray  20  is molded from  555 -ABS material which is commercially available from the Dow Chemical Company. Polystyrene materials having appropriate characteristics can also be used. 
     “Tray  20  is a relatively shallow member and includes a generally planar bottom wall  26 , front wall  28 A, rear wall  28 B and side walls  28 C and D. Lips  30 A- 30 D extend outwardly from the upper edges of respective walls  28 A- 28 D, and circumscribe a film access opening of tray  20 . Inwardly projecting guides  32  are formed on walls  28 A- 28 D to properly position sheets of film (not shown) within tray  20 . Feet  34 A- 34 D are formed into and extend downwardly from bottom wall  26  to support cartridge  12  within base  16  of photographic system  10 . Bottom wall  26  also includes positioning recesses  36  which can be tapered. Positioning recesses  36  are configured to receive positioning lugs extending from base  16 . The position lugs secure and properly orient cartridge  12  within photographic system  10 . In the embodiment shown, position recesses  36  are molded into feet  34 A and  34 B adjacent to front wall  28 A. A media presence monitoring well  35  is also formed in bottom wall  26 . Media presence monitoring sensors of photographic system  10  (not shown) extend into well  35  below the surface of bottom wall  26  when all film has been removed from tray  20 .” 
     Feet  34 A and  34 B (i.e. those adjacent to front wall  28 A) also includes ramp surfaces  38  which slope downwardly from the lower edge of the front wall to the bottom of the feet. Ramp surface  38  guide feet  34 A and  34 B over the position lugs in photographic system base  16  as cartridge  12  is being loaded into the base. The embodiment of tray  20  illustrated in FIGS. 2 and 3 also includes a recess  40  in bottom wall  26  which forms a platform on the bottom exterior of tray  20 . The platform formed by recess  40  is configured to receive an information bearing medium such as a bar code which includes recorded information pertaining to the characteristics of film within cartridge  12 . A pair of feet  41  are formed as recesses in bottom wall  26  adjacent recess  40  to insure proper positioning of the information bearing medium with respect to a reading device (not shown) of photographic system  10 . Reinforcing ribs (not shown in FIGS. 2 and 3) can also be molded into bottom wall  26  and/or side walls  28 A- 28 D to increase the rigidity of tray  20 . 
     The forwardmost or leading edge of front lip  30 A also includes a series of evenly spaced cut-out sections  42 . Cut-out sections  42  form a series of spaced projections  44  on the leading edge of lip  30 A. Cut-out sections  42  and projections  44  cooperate with yet to be described aspects of cover  22  and opening/closing mechanism  18  to facilitate the opening and subsequent closing of cartridge  12 . 
     Cover  22  is a flexible, photo-inert, optically opaque sheet sized to extent over the excess opening of tray  20 . Cover  22  has edges  23 A- 23 D (only edges  23 A and  23 D are shown in FIG. 2) which extend between and mate with tray lips  30 A- 30 D, respectively. In one embodiment, cover  22  is a foil formed by a foil laminate formed by polyethylene bonded layers of one 25 μm thick polyethylene, 8.75 μm thick aluminium foil and 50 μm thick polypropylene. This foil laminate cover  22  is of a sufficiently stretchy nature to prevent the cover from popping off tray  20  when cartridge  12  is flexed, yet rigid enough to prevent detrimental amounts of stretch related buckling when the cover is rolled up. The foil laminate cover  22  also provides for the integrity of a vacuum within cartridge  12 . 
     “In another embodiment, cover  22  is a magnetic foil.” 
     A paper or polyester reinforcing strip (not separately shown) can be added to the leading or front edge  23 A of cover  22  to increase cover rigidity above projections  44  and facilitate the operation of opening/closing mechanism  18 . In one embodiment , the reinforcing strip is a 6 mm wide, 150 μm thick, strip of mylar. The front edge  23 A of cover  22  extends over the tray cut-out sections  42 , and includes elongated apertures  46  which are positioned over the cut-out sections when the cover is sealed onto tray  20 . Apertures  46  facilitate the engagement of opening/closing mechanism  18  with cover  22 . 
     “In one embodiment magnetic segments or strips can be applied on at least a part of the forward lip  30 A and optionally on projecting guide  32 A. Preferably said magnetic strips or segments are applied on at least a part of the forward and side lips  30  and/or on the forward lip  30 A and on the top of the side forwardly projecting guides  32 . More preferably said magnetic strips or segments are applied to the whole forward lip  30 A and on optionally projecting guide  32 A. Most preferably said magnetic strips or segments are applied to the whole forward lip  30 A and optionally to projecting guide  32 A and to a part of the side lips  30  and/or projecting guides  32  adjacent to the forward lip  30 A or projecting guide  32 A. Said magnetic strips or segments are preferably between 0.5 and 30 mm thick, more preferably between 1 and 5 mm thick. The cover then contains iron powder or comprises on the leading edges a metallic strip. Said metallic strips are preferably between 10 μm and 500 μm thick, more preferably between 25 and 100 μm thick.” 
     In another embodiment metallic strips or segments can be applied on at least a part of the forward lip  30 A and optionally on projecting guide  32 A. Preferably said metallic strips are applied on at least a part of the forward and side lips  30  and/or on the forward lip  30 A and on the top of the side forwardly projecting guides  32 . More preferably said metallic strips are applied to the whole forward lip  30 A and optionally projecting guide  32 A. Most preferably said metallic strips are applied to the whole forward lip  30 A and optionally to projecting guide  32 A and to a part of the side lips  30  and/or projecting guides  32  adjacent to the forward lip  30 A or projecting guide  32 A. 
     “Said metallic strip is preferably between 0.5 and 10 mm thick, more preferably between 1 and 5 mm thick. The cover is then made of a magnetic foil. Said foil has a thickness preferably between 0.2 and 2 mm, more preferably between 0.5 and 1 mm.”