DE2750559A1 - SHEET FILM CASSETTE - Google Patents

Description

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Patent attorneys

Dr.-lng. Walter Abitz _{11β November lg77}

Dr. Dieter F. M ο rf PD-1635

Dipl.-Phys. M. GrUschncder
8 MOncben 86, Pienzenauerstr. 28

EGG. DU PONT DE NEMORS AND COMPANY 10th and Market Streets, Wilmington, Del. 19898, V.StJl.

Sheet film cassette

ORIGINAL INSPECTED

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The present invention relates to a sheet film cartridge and, more particularly, to a sheet film cartridge for handling sheet films in daylight and to facilitate your image processing.

It is already from US Pat. No. 3,784,835 (Gunter Schmidt) Sheet film cassette known especially for X-rays is suitable and the processing of the sheet films is permitted in daylight. This sheet film cassette has a housing with a front and rear plate spaced parallel to each other are arranged. A pressure plate lies between the front and rear plates and becomes resilient and light-tight against the front plate pressed. The cassette is formed with channels running along the opposing edges of the cassette extend to slidably receive rod-shaped cam members. The pressure plate is pegged along its edges equipped that slide on cam surfaces of the cam members. Actuating pins are provided on the sheet film cassette, which, when pushed down, engage the cam members and thus slide them within of the channels cause the cam surfaces to lift the pegs and the pressure plate spaced from the front plate keep. Thereby, the sheet films are set in the sheet film cassette or removal of the same from the sheet film cassette is possible.

Although the sheet film cassette has a wide field of application, however, it was particularly designed for use with X-ray films. The front plate and the pressure plate were with coated a fluorescent material which had to be kept in close contact with the sheet films in order to obtain the to transfer X-ray images formed on them onto the sheet film. Lately it would be particularly desirable to take advantage of these daylight cassettes in other film systems, especially in medical applications such as for example axial tomography. In axial tomography, a computer analyzes several X-ray scans and creates an image that is displayed on a television tube-like screen. The image generated on the screen

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is then using a commercially available photo camera imaged on a film cassette located in the photo camera. The film is then removed from the cassette and developed. It is very desirable to use a cassette in connection with such a photo camera that can be handled in daylight.

It is therefore an object of the invention to provide a sheet film cassette that can use photographic films in daylight.

Another object of the invention is to provide an improved sheet film cartridge.

According to the invention, a sheet film cassette is created, which has a flat frame defining an inlet for the sheet film and an exposure aperture around the edges of the sheet of film in a fixed focal plane, as well as a pressure plate that presses resiliently against the frame to keep the To hold edges of the sheet film between the exposure opening and the printing plate, the printing plate at least one Has cam follower element, rod-shaped cam elements at least form a cam surface, a fastening device, the rod-shaped cam elements on the frame for linear movement mounted with respect to the frame between first and second positions with the cam surface in abutment with the Cam follower is standing, the cam surface has a shape to the cam follower and thus the pressure plate away from the exposure aperture while the rod-shaped cam elements move from the first to the second position move a light shield next to the sheet film inlet to allow light to enter through the inlet to the exposure aperture and to prevent the pressure plate when the rod-shaped cam elements are in their first position, the frame having elongated guide tracks along the exposure opening and an entry slot and a sliding plate through the entry slot can be pushed into the guide tracks in order to allow light to enter through the exposure opening

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To block.

According to a preferred embodiment, a lock is provided on the frame in order to close the sliding plate in one position hold in which it blocks the exposure aperture. Furthermore, a light shield is provided in the inlet opening, to prevent light from entering the area adjacent to the printing plate. The light shield consists of one flexible sheet that attaches to the frame at the inlet opening is and bears resiliently on the sliding plate. The flexible blade is equipped with a number of individual fingers, each of which covers part of the sliding plate.

The invention will then be explained using an exemplary embodiment described in connection with the drawings. Show it:

1 shows a plan view of the frame of the sheet film cassette with the exposure opening directed downwards according to a preferred embodiment of the invention,

FIG. 2 is a section along line 2-2 of that shown in FIG Sheet film cassette,

FIG. 3 shows a partial section along the line 3-3 in FIG. 1 sheet film cassette shown,

FIG. 4 shows a partial section along the line 4-4 in FIG. 1 sheet film cassette shown,

Fig. 5 is an exploded perspective view a sheet film cassette according to the invention using the frame according to FIG. 1,

FIG. 6 is a partial side view from which the mode of operation of a rod-shaped one used in the cassette according to FIG. 5 Cam element is apparent, and

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Fig. 7 is an illustration of the cassette with partially withdrawn Sliding plate.

The sheet film cassette according to the invention is suitable for receiving and maintaining photographic actinic radiation (light) responsive sheet films that are self-acting Film output device can be removed, which preferably forms part of a daylight handling system, such as it is sold by E. I. du Pont de Nemours & Co. (Inc.), Wilmington, Delaware, USA. Such an output device is, for example, in US Pat. No. 3,790,160 (Gunter Schmidt) described. The sheet films used in connection with such a system are according to the American patent 28438 (Reissue Patent) notched and stacked, to facilitate delivery from the light-tight dispenser. The output device can be operated in such a way that it opens an envelope containing the stack of sheets of film and dispenses the sheets of films one by one into the cassette. The output device works with the cassette to open the cassette so that a sheet of film can be loaded into it can, whereupon when the cassette is removed from the output device, the cassette is again closed light-tight to the Allow handling of the sheet film in daylight. The sheet film is then in the rear part of a commercially available Photo camera is arranged, a shielding plate blocking the exposure opening is removed, the sheet film is exposed, the shielding plate put back in place and the cassette out of the camera for further processing of the Taken from sheet film. The cassette can then be inserted into a sheet film storage magazine, such as, for example in U.S. Patent 3,715,087 issued to Gunter Schmidt. The sheet film is developed in the sheet film storage magazine or otherwise treated. The advantage of the daylight system is of course that no darkroom is required to place the sheet film in the cassette to be entered and taken from this. This leads to a considerable saving of time and a considerable reduction in workload.

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The sheet film cassette according to the invention has a light-tight one Housing provided with an open exposure opening 12 through which the film can be exposed, as well as with a removable slide plate 14 which blocks the exposure aperture light-tight and with a rear plate 16. The housing has an inlet opening 18 through which the sheet film can be fed in from the dispenser, and a slot-like one Entry opening 20 through which the slide plate 14 can be withdrawn to allow exposure of the sheet film to allow.

The housing 10 consists of a flat frame with a U-shape Channels 22 on each side of the frame. A beveled entry port member 24 and a cross member 26 connect the channels 22. The transverse element 26 and the inlet opening element 24 are connected with an epoxy resin serving as an adhesive. A rectangular window frame 30 is attached to the inner section of the edge of the frame lying at the bottom in the drawing, which tracks 31 for light-tight reception of the sliding plate forms. The bottom part of the transverse element 26 is dimensioned in such a way that it can be fitted with a detachable plate 32 (after removal of screws) an extension of the tracks 34 and entry slot 20 to build. A stationary platen 36 is adjacent to the detachable plate 32 arranged and fixed by resin to the frame tied together. These two plates 32 and 36 enclose a cavity 38 in the transverse element 26, in which a light shield is attached.

The light shield 40 expediently consists of an elastic, spring-like element, which is made, for example, of stainless steel and which is attached to the transverse element 26 by means of screws 42 is attached. The resilient element 40 is preferably formed with flexible fingers 44 which are particularly desirable since they allow the light shield to rest on the sliding plate 14 over its entire width at all points and the light shield is not curved to allow incidence of light to the cassette. The fingers are preferably with a layer made of opaque velvet or plush-like material

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known type covered to facilitate light shielding. The frame is at the entry slot 20 with a beak 46 provided that works as a barrier. The beak 46 can bear against a widened handle 48 on one edge of the Step sliding plate 14 to facilitate their removal. This system holds the sliding plate securely in place so that it does not accidentally fall out.

At the end of the description of the framework, it should be noted that that rod-like cam elements 50, which are made of sheet metal can have an L-shaped cross-section and are displaceable within the channels 22. The cam surfaces 54 »the, as will be described, come into contact with the cam follower elements 56 on the pressure plate 58, are made in a similar manner Sheet metal produced and on the rod-shaped cam elements welded or otherwise attached. The ends of the rod-shaped cam members 50 adjacent the inlet opening 18-18 receive pins 60 in a U-shaped container formed in the cam members to accommodate the rod-shaped squat members can be actuated by associated pins, not shown, on the film sheet dispenser or magazine. The inner ones Walls of the channels 22 are cut out accordingly to provide a sliding reception of the existing on the pressure plate 58, as To permit protrusions formed cam followers 56 to and to form pivot pins 61 about which the resilient strips 40 can pivot as they pass through the cam surfaces 54 can be operated. Compression springs 62 are arranged in the rod-shaped cam elements 50 and are attached to a The end is held by a projection, not shown, of the cam elements 50. Pins 64 can pass through channels 22 and inserted through slots in the rod-shaped cam members 50 to close the other end of the compression springs 62 attach. Thus, when the rod-shaped cam elements 50 are actuated, the compression springs are pressed together.

The cam surfaces 54 include actuation surfaces 70 for actuation the pressure plate and pivoting the resilient strip in contact with the pressure plate and on the other hand for the plant

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Printing plate on the exposure window. The elastic springs designed as strips 4-0 have to make every one to _t end openings 90 which fit over the pivot pins 61, which are present in the channels 22 about a pivot point for the elastic strips. Similarly, cam follower fingers 94 are located at each end of the resilient strips and are capable of engaging the platen actuation surface 70 and pivoting the pliable fingers 44 to abut the platen.

A retrieval cam 72 for moving the pressure plate 58 away from the exposure window upon actuation of the rod-shaped cams, for example by depressing the pins 60, is arranged on the rod-shaped cam elements. In addition, a strip 7 ¹ J serving as a light shield has end projections or pegs 76 which engage in notches or slots 78 in the channels 22 in such a way that the strip can be pivoted between an open position and a closed position, whereby the inlet opening 18 with regard to the entry of Light is opened or closed.

The strip 74- forming the light shield is through the Movement of the pressure plate actuated and is provided with resilient projections 79, which serve as a light shield Bring strip 74- to a closed position where it is against the end of the printing plate pushes if it is not opened by moving the printing plate into an open position (away from the exposure window). The pressure plate 58 allows it the projection 56 of the rod-shaped cam follower element, itself to move within the confines of the slots 80 in the channels 22. The pressure plate 52 is with a surface 59 on the Film bearing side covered, which forms a layer of air between the film and the cam surface. The area 59 should also be non-electrostatic so that the film can slide freely over the surface of the platen and when using the cassette is pivoted at one end, can fall freely out of the cassette or can be removed from it when the pressure plate is opened.

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Such a surface can be made by using a polyester film is adhesively connected to the film support surface of the printing plate and the polyester film is coated with a suspension which forms a surface made up of points. The surface can be obtained by placing silicone beads with a diameter of about 0.025 mm in a Cellulose acetate solution are suspended. A black dye is added to the cellulose acetate solution to reduce the To reduce the tendency to conduct light between the film surface and the grid surface. The pearls take about 1 to 2 vol.% A. The suspension is applied to the front of the printing plate applied and allowed to dry; the polyester film base protrudes slightly beyond the printing plate and is bent back at 61 to create a beveled opening for the frame with the lower section 63 (FIG. 3) of the frame To form sheet film.

The rear of the frame slidably receives a rear panel 16 to terminate the cassette. For this purpose, the Plate 16 slide in grooves 84 provided in channels 22. The handle 41 forming the cavity 38 is at 43 provided with a recess so that the slide plate 14 can be removed by grasping its handle 48.

In operation, the pressure plate 58 normally detects the edges of the window frame 30 »by a sheet of film, not shown to grasp at its edges. The pressure plate rests against the edges due to the action of the compression springs 62, the rod-shaped cam elements 50 against the inlet opening 18 of the housing 10 are pressed. This ensures that the Cam surfaces 72 from those working as cam follower elements Projections 56 (Fig. 6) are released and at the same time the pressure-exerting cam surfaces 72 are caused, the cam followers forming finger 94 and the fingers 44 of the elastic strip 40 against the back of the pressure plate 58 to pivot. At the same time, when the pressure plate is depressed, the light shield 74 can pivot because the leaf springs 78 the inlet opening 18 against incidence of light

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to lock. The spring strips 40 now grip the sliding plate 14 to prevent light from entering the interior of the cassette in the area between the printing plate and the exposure window via this entry path.

The cassette is now in the rear part of a commercially available Photo camera entered for exposure and the sliding plate 14 is attached to the beak 46 acting as a lock taken over. After the sliding plate has been removed, the elastic strip 40 closes the opening to allow light to enter to prevent in the cassette. The effect of each finger ensures that there is no light around the edges and across can enter the surface of the slide plate while it is being removed.

After exposure, the sequence of the individual steps is reversed. The slide plate is reinserted past the beak 46 into the entrance opening 20 to the exposure window complete and protect the exposed sheet film from incidence of light. The fact that during the exposure of the Sheet film can rest against the pressure plate and is held at all edges, contributes to the sheet film - even if it may be relatively thin - to be kept in the focal plane of the camera optics. The focal plane is maintained, itself when the cassette is turned film side down, d. H. the cassette can be used in any warehouse and still works in an advantageous manner.

After exposure, after inserting the sliding plate, the cassette can be removed from the camera and placed in a film magazine of the type described in the aforementioned patents. When inserted into this magazine Release pins (not shown) engage the pins 60 so that they are depressed in the cassette. This will compresses the compression spring 62 and moves the cam surfaces 54 such that the pressure of the spring strips 40 against the pressure plate released and the printing plate is brought out of contact with the edges of the exposure window. The removal of the printing

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plate causes the light shield to pivot upwards 74 under tension setting its leaf springs and opens through Pivot the shield 74- at the inlet opening 18. When the cassette is in a vertical position with the inlet opening pointing downwards, the sheet film slides freely out of the cassette out and over the layer of air present on the surface of the printing plate.

The pressure plate itself is released, in particular by the cam surface 70 out of contact with the resilient, as Cam followers trained fingers 94- is brought, as is indicated by dashed lines in FIG. 6, the cam surfaces 72 serving for lifting capture the projections 56 and they in the position shown in phantom in Fig. 6, whereby the printing plate is raised out of contact with the exposure window will. This means that there is a double effect consisting of release and form-fluid actuation of the cam surface, which retracts the platen and opens the cassette. If the cassette is to be reloaded, it goes up with directed inlet opening according to the aforesaid U.S. Patents brought into a sheet film dispenser. the Pins are depressed again to open and enter the entry port in the manner previously described Sheet film is fed into the sheet film cassette through the dispenser, all of which is done in daylight. Upon removal from the dispenser, the pins are released, the sheet film cassette is closed, and the cassette is closed is ready for operation in the light-tight state.

The cassette according to the invention forms an inexpensive one in terms of cost Unit that can be easily manufactured and yet provides a light-tight seal for the contents of the cassette Provides. The individual elastic fingers on the light shield allow the sliding plate to be easily removed 14 for taking pictures. The point-like, non-electrostatic surface of the printing plate represents a Air layer available and allows free gliding

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of the Blattfiltas when removing the same. The Blattfilra will releasably and firmly held at its edges in the desired focal plane.

End of description

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Claims (1)

27SBb9 PD 1635 11 November 1977 Claims 1.) Sheet film cassette with a flat frame that has a forms side entry for a sheet of film, a pressure plate that presses elastically against the frame defining at least a portion of a sheet of film between the frame and the printing plate, the printing plate has at least one cam follower element and rod-shaped cam elements at least one cam surface form a fastening device · the rod-shaped Cam elements on the frame for performing a linear movement with respect to the frame between a first and second position attached, the cam surface to the Cam follower element is applied, the cam surface is designed such that the cam follower element and thus the Pressure plate is moved away from the frame when the rod-shaped cam followers move from the first position move to the second position and a light shield is placed next to the inlet for the sheet film to prevent the entrance to prevent light through the inlet when the rod-shaped cam elements are in the first position, characterized, that the frame (1O) forms an exposure opening (30), which holds the edges of a sheet of film in a fixed focal plane, that the frame has elongated guideways (3Ό, which lie along the exposure opening (30) soxvie an entry slot (20), and that a sliding plate (14) can be pushed through the entry slot (20) into the guide tracks (31) in order to avoid the passage of light through the exposure aperture (30). 2. sheet film cassette according to claim 1, characterized in that the frame (10) has a lock (46) to the 2 V b U b b d PD-1635 1 To hold the sliding plate (14) in a position in which the exposure opening (30) is blocked. 3 · sheet film cassette according to claim 2, characterized by a light shield (7 ^) to prevent passage of light through the entrance slit into the area adjacent to the printing plate. 4. sheet film cassette according to claim 3 _5, characterized in that the light shield (7 ^) consists of a flexible film which is attached to the entry slot (20) on the frame (10) in order to resiliently grasp the sliding plate (14). 5. sheet film cassette according to claim 4, characterized in that the flexible sheet has a number of individual fingers (44) which bear against the sliding plate (14). 6. sheet film cassette according to one of the preceding claims, characterized in that the pressure plate (14) has a surface formation that is at least partial Air layer between a sheet film and the pressure plate (14) allows the sliding movement of the sheet film in to allow the cassette and out of the cassette. B 0 9 8 ? Π / 0 9 L