STORAGE FILM FEED

Description

[0001] The present invention relates to a storage plate feeder for feeding a storage plate from a flexible sleeve open on one side at one end into a storage plate scanner - in short a drum scanner, as is known for example from DE 199 42 211, as well as to a storage plate scanner provided with such a storage plate feeder.

[0002] Such image plate scanners are used in the dental field to scan intraoral image plates in formats ranging from 24x30mm to 56x75mm after X-ray exposure in the patient's mouth, as well as extraoral image plates in formats ranging from 127x300mm to 240x300mm. In the medical field, image plate sizes can reach up to 350x430mm, and in non-destructive material testing, up to 100x400mm. Since the image plates lose their stored information when exposed to light after X-ray exposure, they must be enclosed, at least on the functional side, in light-tight covers (light-protective covers) or cassettes until the information is scanned in the image plate scanner.To prevent the sleeve from being drawn into the image plate scanner along with the image plate, DE 199 42 211, for example, proposes using special insertion devices in the form of cassettes, specific to the respective plate format, from which the image plate can be advanced into the image plate scanner. Alternatively, it is known in the prior art to provide flexible light-shielding sleeves with form-fitting elements so that they lock into the feed area of ​​the image plate scanner and cannot be drawn in. Furthermore, it is expedient to thicken the cassettes and flexible light-shielding sleeves at the feed gap of the image plate scanner so that this is shielded from ambient light.The disadvantage of the first solution is that it requires significantly more handling, as the image plate must first be pushed out of the sleeve into the insertion aid, then the insertion aid must be locked to the image plate feed area of ​​the image plate scanner, and then the image plate must be pushed into the image plate scanner using a lever on the insertion aid. The disadvantage of the second solution is that the flexible light protection sleeve, equipped with form-fitting elements, no longer fits easily into conventional X-ray cassettes.

[0003] JP 2006 091126 A discloses an image plate feeder for feeding an image plate from a cassette whose front end can be closed with a flap. While the cassette is inserted into an image plate scanner, a movable cover rests against the flat side of the cassette to prevent dirt particles from entering the image plate scanner. As soon as the front end of the cassette reaches and actuates a locking or release mechanism inside the image plate scanner, the flap opens, allowing the image plate to exit the cassette and be scanned in the image plate scanner.

[0004] US 2008 / 042083 A1 and US 5 315 632 A also disclose image plate feeders for feeding image plates from fixed cassettes.

[0005] JP 4 073734 A describes a cassette having at least a partial opening and accommodating the stimulable phosphor sheet, a lid movable in sliding contact with a part of the cassette to open and close the opening, and a mechanism provided in a part of the lid to engage with a member provided in the loading section of a recording and reading apparatus to open the lid when the cassette is loaded into the apparatus.

[0006] JP 2006 195072 A describes an X-ray image reading apparatus for reading an X-ray image from a photostimulable phosphor sheet stored in a cassette in a housing, wherein an insertion opening is formed in the housing and rotates about an axis perpendicular to the insertion direction of the cassette.

[0007] US 6 046 458 A describes a protective cover for a storage plate, which covers at least the radiation- and light-sensitive surface of a storage plate and consists of a material which is transparent to the radiation used in imaging but essentially impermeable to light.

[0008] JP 58 004135 A describes a cassette holder that moves between a preparation position and a photo position and has right and left stops for clamping the cassettes.

[0009] US 6255 667 B1 describes a device for reading a phosphor film while it is positioned in a curved shape.

[0010] US 2006 / 113500 A describes an X-ray reading device for reading X-ray information stored in a phosphor plate contained in a cassette. The device comprises an insertion device into which the cassette is inserted, an elongated insertion opening through which the phosphor plate contained in the inserted cassette is conveyed into an internal cavity of the X-ray reading device, and at least one closure mechanism that is moved in a longitudinal direction relative to the insertion opening to close at least a second portion of the insertion opening.

[0011] The invention described below aims to feed the image plate to an image plate scanner without aids such as cassettes made of simple sleeves that may not necessarily have form-fitting elements, while protecting it from extraneous light, and to significantly reduce the number of handling steps. Furthermore, the image plate is to be automatically clamped cylindrically in a cylindrical scanning arrangement as in DE 199 42 211, thus eliminating the corresponding handling effort.

[0012] This object is achieved by an image plate feeder integrated into the image plate scanner according to the main claim. Further embodiments of the invention are set out in the subclaims and will be illustrated in more detail with reference to the figures. Fig. 1shows a section through an exemplary imaging plate feeder after the imaging plate has been placed in the sleeve, which is not part of the present invention, Fig. 2 shows the same with the image plate partially removed from the cover, Fig. 3 shows another exemplary image plate feeder with integrated adhesive coating, which is not part of the present invention, Fig. 4 shows another exemplary image plate feeder with integrated light protection and form fit for holding the sleeve, which is not part of the present invention, Fig. 5 and Fig. 6 an exemplary image plate feeder with a partially tilted support surface, which is not part of the present invention, Fig. 7 and Fig. 8 two possibilities, which represent the arrangement of the image plate feeder on the housing of the image plate scanner, while Fig. 9 and Fig. 10 show a tangential feeding or removal of the image plate. Fig. 11 and Fig. 12represent an inventive image plate feeder with a fixed passage gap for the image plate.

[0013] In Fig. 1 A cross-sectional view of an image plate feeder is shown. It is attached to a housing 5 of an image plate scanner and comprises a slider 4, which can be moved back and forth below an insertion opening 18 of the image plate feeder relative to a stop piece 6 fixed to the housing 5 in the direction of the arrow using a drive M. For this purpose, a motor-driven push rod, a motor-driven spindle, or a lifting magnet can be used. These elements are shown in Fig. 1Only shown schematically for the sake of clarity. The slider 4 is guided either on the housing 5 or on the stop piece 6. The underside of the slider 4 forms a flat support surface 10, onto which a flexible sleeve 2 equipped with a storage plate 1 and open on one side at one end, can be easily placed manually from above with its open, likewise flat end. This vertically aligns the sleeve 2 and thus the storage plate 1. The support surface 10 is designed such that it engages the stop piece 6 and is also guided linearly therein. In the example, a groove 60 is arranged in the stop piece 6 as a guide element for the slider 4, in which groove a web of the slider 4 forming the support surface 10 is guided. In the lower part of the slider 4 there is a passage gap 9, the width of which is slightly greater than the thickness of the storage plate 1.This gap 9 forms a passage opening for the image plate 1 into the interior of the housing 5, where it is gripped by a feed 8 for further transport.

[0014] The inner surfaces of the passage gap 9 are provided with a soft, low-friction coating or layer, such as PTFE (Teflon) or LDPE (Low Density Polyethylene), in order to reduce possible friction between the scratch-sensitive front side of the image plate 1, i.e. the flat side facing the X-ray source during exposure, and the slider 4 in the event of a fault. On the front side of the slider 4 facing the image plate 1 or the stop piece 6, a compression piece 7, e.g. made of soft rubber foam, is arranged, which covers the passage gap 9. Suction air channels 3 can be arranged opposite in the stop piece 6, which have the function of holding the sleeve 2 when the slider 4 is pressed against the stop piece 6. Since it is unfavorable if ambient light falls into the image plate scanner, it is important to ensure the connections between the parts of the image plate feed, i.e.The connection between the slider 4 and the stop piece 6 and the housing 5 should be as gap-free and light-tight as possible to prevent light from entering the interior of the scanning device. It may be necessary to suppress the light penetration by using tongue and groove elements on the connecting surfaces and blackening the abutting edges.

[0015] In order to detect whether a storage plate 1 has been placed in the insertion opening 18 on the support surface 10, a sensor, for example a reflex light barrier, is installed in the slide 4 or the stop piece 6. According to the invention, a photodiode 17 ( Fig. 7 ) and a light-emitting diode 16 ( Fig. 7 ) in these two parts form a forked light barrier to detect the image plate.

[0016] If a storage plate 1 located in a casing 2 that is open at one end is placed with this open end in the insertion opening 18 on the support surface 10, the sensor sends a signal S to a control unit P, which either immediately or after a short delay moves the slide 4 perpendicular to a flat side of the casing 2 to the left (closing direction) with the drive M. Alternatively, the signal S1 can be triggered by a button 19 (see Fig. 8) are generated on the housing 5. By moving the slider 4 to the left, the sleeve 2 with the image plate 1 contained therein is pushed towards the stop piece 6 until its flat side rests against it. The compression piece 7 is compressed and clamps the sleeve 2 from the outside with a certain spring force. When the image plate 1 with its sleeve 2 rests against the stop piece 6, its front side is aligned with the passage gap 9. It is important that the static friction between the stop surfaces of the stop piece 6, the compression piece 7 and the sleeve 2 is significantly greater than the static friction between the sleeve 2 and the image plate 1 located inside. In other words: the static friction coefficients between the image plate 1 and the inner surfaces of the sleeve 2 are lower than the static friction coefficients between the outer surfaces of the sleeve 2 and the stop surface of the stop piece 6 or the compression piece 7 of the slider 4.For this purpose, the inside of the sleeve 2 is made of a soft, low-friction material to reduce wear on the image plate 1. The image plate 1 can additionally be provided with at least one low-wear cover layer, which preferably has a higher surface hardness than the material on the corresponding inner side(s) of the sleeve 2. The image plate 1 can also bear inscription that is less wear-resistant than the sleeve 2 and has a higher surface hardness than the material on the corresponding inner side(s) of the sleeve 2.

[0017] Both the end face of the compression piece 7 facing the stop piece 6 and the stop surface of the stop piece 6 can be provided with an adhesive layer to increase the static friction.

[0018] In this way, the image plate feeder and the image plate 1 with the sleeve 2 form a system in which the individual components - image plate feeder, image plate, and sleeve - are coordinated with one another. In practice, when using a sleeve 2 made of LDPE and a silicone coating on the compression piece 7, it has been shown that with a pressure force of 1.6 N exerted laterally by the slider, the adhesive force of the sleeve 2 on the compression piece 7 of the slider 4 is approximately 1.1 N and the adhesive force of the image plate 1 in the sleeve 2 is approximately 0.4 N. In this way, it is guaranteed with a safety factor of almost 3 that the image plate 1 can be pushed out of the sleeve 2 with a finger, while the sleeve 2 itself remains fixed in the insertion opening 18 on the slider 4 or on the compression piece 7.

[0019] In order to guide the sleeve 2 and thus the image plate 1 contained therein laterally along its narrow sides running perpendicular to the front face, a lateral support element can also be arranged on the stop piece 6 or the housing 5, resting against a narrow side of the sleeve 2. To enable different image plate and feed widths, the support element can also be positioned in different positions, e.g., by means of a snap-in connection.

[0020] Fig. 2shows the state when pressure is subsequently applied to the closed end of the sleeve 2, and thus to the image plate 1, which is facing away from the open end, said sleeve being pushed downwards through the passage gap 9. This can be done, for example, manually or motor-controlled by another slider or lever acting from above. Below the passage gap 9, the image plate 1 meets the feed 8, for example in the form of a belt transport. This continuously pulls the image plate 1 further downwards while the sleeve 2 remains clamped between the stop piece 6 and the compression piece 7. The compression piece 7, which is made of opaque material, seals off a separation gap remaining between the stop piece 6 and the slider 4.In this position, the distance between the stop piece 6 and the slider 4 is slightly greater than the thickness of the image plate 1 including the sleeve 2, so that no significant pressure is exerted on the sleeve 2 by the slider 4 itself but only by the compression piece 7.

[0021] The clear width of the passage gap 9 is slightly larger than the thickness of the image plate 1 so that its inner surfaces do not touch the image plate 1 in this position and, for example, each have a minimum distance of 0.3 mm from the image plate 1.

[0022] On the underside of the stop piece 6 facing away from the insertion opening 18, there is a sensor 11, for example a light barrier, which generates a signal S2 indicating that the image plate 1 has been advanced through the passage gap 9. The signal S2 of the sensor 11 can be used to start the feed 8, here schematically indicated in the form of a belt transport. The sensor 11 also detects when the image plate 1 leaves the passage gap 9 again, i.e. has completely passed through it. With the signal S2 generated by the sensor 11, the slide 4 is returned to the starting position according to Fig. 1 pushed so that another image plate 1 with its cover 2 can be applied. Alternatively, the opening of the slider 4 can also be controlled by a button 19 ( Fig. 8), which is attached to the housing 5, can be triggered by the user. During this process, the compression piece 7 closes the passage gap 9 again in a light-tight manner. In a further variant, a delay circuit can also be implemented in the control unit P, so that the slider 4 is only moved to the starting position after the image plate 1 has been completely scanned. This always ensures that no external light can enter during the scanning process due to the movement of the slider 4 and thus the scanned image does not contain any interference.

[0023] Fig. 3shows an image plate feeder in which the stop surface of the stop piece 6 is provided with an adhesive coating 12, e.g., made of silicone rubber. Furthermore, a light protection element 13, such as a brush, is arranged below the passage gap 9, covering the passage gap 9 and providing additional light protection. When the image plate 1 is inserted, this light protection element is bent downward and thus pivots away from the passage gap 9.

[0024] As an alternative to the adhesive coating 12, a positive fit of the sleeve 2 with the insertion opening 18 can be used when closing the slider 1, as shown in Fig. 4For this purpose, for example, a narrow, wedge-shaped web 14 can be applied to the sleeve 2 as a positive connection, which engages in a corresponding recess 15 in the slide 4 when the slide 4 is actuated in the closing direction and prevents the sleeve 2 from being pulled through the passage gap 9 when the slide 4 is closed. The opaque compression piece 7 is still attached to the slide 4 to seal against ambient light. Such a positive connection 14, 15 can also be provided between the sleeve 2 and the stop piece 6 as an alternative or in addition.

[0025] The Fig. 5 and Fig. 6 show a variant in which the flat support surface 10 is aligned with the underside of the stop piece 6 (image plate 1 in the starting position Fig.5) is arranged on the slide 4 by means of a hinge and can be pivoted by 90 degrees about an axis oriented parallel to the support surface 10 of the image plate 1, which corresponds to the position with the image plate 1 extended ( Fig. 6 ).

[0026] Fig. 7 shows a schematic of a cylindrically curved image plate feeder. This design can be used particularly advantageously in conjunction with the scanning device described in DE 199 42 211, since the image plate acquires a cylindrical shape due to the action of the feeder. The central arrangement of LED 16 and photodiode 17 relative to the insertion opening 18 can be seen. In principle, with the appropriate shape of the slider 4 and the stop piece 6, the feeder can bend the image plate into other shapes, e.g., into a parabolic or elliptical shape.

[0027] Fig. 8shows a further perspective view of the image plate feed, which can also be used for the scanning device known from DE 199 42 211. Here, too, it is possible to arrange the light-emitting diode and photodiode centrally to the insertion opening 18. The advantage of this arrangement is that the sleeve 2 equipped with the image plate 1 can be inserted into the insertion opening 18 in a very simple manner, which is necessary for fully automatic operation. Furthermore, an additional feed slide 20 can be provided, which can be actuated parallel to the flat side of the inserted image plate 1 or sleeve 2, in the example in the vertical direction, and with which the image plate 1 is pushed forward into the transport area after the slide 4, which is horizontal in the example, has been closed. The slide 20 engages the upper side, i.e. the end side of the sleeve 2 equipped with the image plate 1 which is facing away from the open end side.The feed slide 20 is preferably flat on its underside facing the end of the sleeve 2, so that tilting of the image plate 1 when pushed out of the sleeve 2 is avoided. If the feed slide 20 is motor-driven, the feed is fully automatic and the user's handling is limited to placing the image plate 1 with the sleeve 2 open on one side onto the support surface 10 of the insertion opening. The feed slide 20 then pushes the image plate 1 through the passage gap 9 by means of a motor drive after the slide 4 rests against the sleeve 2 and clamps it in place. The feed slide 20 is moved back to its starting position by the motor drive once the image plate 1 has left the passage gap 9.It should be noted at this point that the feed also works with fixed cassettes whose lower contour corresponds to the shape of the feed slot 18 and which have an opening on the underside which is aligned with the passage gap 9. Furthermore, with the aid of the feed slide 20, the image plate 1 can be pushed downwards out of such a cassette if the cassette, for example, has openings through which the feed slide 20 can act directly on the image plate, or for example has a further coupling piece which protrudes from the cassette and connects the feed slide 20 to the upper edge of the image plate.

[0028] In conjunction with a readout unit, as already described in DE 199 42 211 and there in Fig. 11 As shown, the image plate feeder according to the invention can be used to Figs. 9 and 10 The particularly compact image plate scanner shown here can be realized. Fig. 9Illustrated is a storage plate scanning device in which the storage plate is drawn in and ejected tangentially to a drum 25 rotating about a rotational axis, in which a laser is arranged that rotates with the drum 25. In this case, the insertion opening 18 and the outlet opening 24 have the shape of a slot oriented parallel to the rotational axis.

[0029] The cross-sectional image according to Fig.102 shows the casing, in which the image plate 1 is still partially located, which, by means of a roller drive 8, is just entering a quarter-circular carriage 22. The carriage is provided with perforations for better adhesion of the image plate 1, which are activated by actuating a vacuum pump 21 as soon as the image plate 1 has reached a stop 23. The image plate 1 is then scanned by the laser beam L, indicated by dashed lines and extending in a plane, while the carriage is simultaneously moved forward, for example by means of a rack and pinion drive (not shown). After this process is completed, the stop 23 releases the image plate 1, the vacuum pump 21 is deactivated, and the image plate 1 appears at the outlet opening 24.Additionally, another pair of driven rollers (not shown) may be provided if gravity is not sufficient to move the image plate 1 sufficiently far out of the outlet slot 24. The same applies if the carriage, or the image plate 1, is larger than a quarter circle.

[0030] In Fig. 11 A storage plate feeder according to the invention is shown. Here, the compression piece 7 is modified from Fig. 1attached to the stop piece 6 and projects beyond the stop surface. Furthermore, the support surface 10 and the passage gap 9 are firmly connected to the stop piece 6. The suction air channels 3 penetrate the stop piece 6 and the compression piece 7. In the rest position of the slide 4, the compression piece 7 preferably covers the entire passage gap 9 so that no extraneous light can get into the scanning device. The compression piece 7 can for this purpose be made, for example, of soft, easily compressible rubber material which has a high adhesion coefficient compared to the sleeve 2. Furthermore, the compression piece 7 can also be slidably mounted in the stop piece 6 so that it is pressed out of the stop piece 6 towards the slide 4 by a spring. The spring constant of this spring determines the pressure force with which the image plate sleeve 2 is clamped and held when the slide 4 is closed.Furthermore, this displaceably mounted compression piece (not shown) is preferably equipped with stops in the stop piece 6 so that it can be pushed to the left as far as necessary until the passage gap 9 is completely clear, and to the right as far as necessary for the entire passage gap 9 to be covered by the compression piece. Furthermore, the displaceable compression piece (not shown) can consist of several sub-segments that correspond to the feed width of different image plate formats. This ensures that the gap 9 is covered in a light-tight manner by segments of the displaceable compression piece, even in positions where no sleeve 2 is present. Furthermore, the displaceable compression piece 7, as well as the slider 4, is preferably provided with a coating that has a high adhesion coefficient compared to the sleeve 2.If the image plate 1 is placed on the support surface 10, the slider 4 is then advanced to the right side of the passage gap 9, so that the sleeve 2 is clamped between the slider 4 and the clamping piece 7 or the stop piece 6. Fig. 12 shows the image plate 1 after it has been partially pushed through the passage gap 9.

[0031] A further advantage of the feed compared to a design in which the image plates are fed in cassettes is the lower overall height, because both the support elements for the cassette are omitted and the cassette with its actuating means for pushing out the image plate itself takes up more space than the image plate contained therein.

[0032] Another advantage is that, with a centrally positioned sensor in the feeder, the transport only starts when the image plate 1 covers the center of the feed gap. This ensures that the image plate is securely drawn in and transported further by the belt transport located centrally below.

Claims

1. Storage film feed for feeding storage film (1) from a flexible casing (2) which is open on one side on a front side into an storage film scanning device, having an insertion opening (18) having a passage gap (9) for the storage film (1), having a stop piece (6) arranged on one side of the insertion opening (18), having a flat support surface (10) for the application of the casing (2) with its open front side, having a slider (4), which is arranged on the side of the insertion opening (18) facing the stop piece (6) and works relative to the stop piece (6) and perpendicularly to a flat side of the casing (2), for fixing the casing (2) in the insertion opening (18), the slider (4) being configured to place the flat side of the casing (2) against the stop piece (6) when the slider (4) is actuated, characterised in that an elastic compression piece (7) which is configured to be compressed by actuation of the slider (4) and to clamp the casing (2) with a spring force exerted on the cover (2) from the outside, wherein the elastic compression piece (7) is arranged at the stop piece (6) and the flat support surface (10) and the passage gap (9) are firmly connected to the stop piece, wherein the elastic compression piece (7) is configured in such a way that the elastic compression piece (7) completely covers the passage gap (9) in a position in which the slider (4) is not actuated, and that the elastic compression piece (7) is pressed by the slider (4) and the casing (2) in the closing direction by actuation of the slider (4) at most until the passage gap (9) is completely uncovered by the elastic compression piece (7).

2. Storage film feed according to claim 1, wherein the compression piece (7) and the slider (4) have an adhesive coating (12) to increase the static friction coefficients of the casing (2) with respect to the stop piece (6) and the slider (4), and / or wherein suction air channels (3) are arranged in the stop piece (6) and / or in the compression piece (7) to hold the casing (2) in place when the slider (4) is actuated.

3. Storage film feed according to one of claims 1 to 2, having a sensor (16, 17) which is installed in the stop piece (6) and / or in the slider (4) for detecting the application of the storage film (1) located in the casing (2) onto the support surface (10) and / or having a sensor (11) on the inner of the stop piece (6) and / or of the slider (4) for detecting whether the storage film (1) has completely passed through the passage gap (9) and / or having a drive (M) which presses the slider (4) against the casing (2) when the storage film (1) in the casing (2) is applied onto the support surface (10) of the slider (4) and moves the slider (4) back when the storage film (1) has completely passed through the passage gap (9).

4. Storage film feed according to one of claims 1 to 3, having an additional slider (20) which can be moved in the direction of the insertion opening (18) and by means of which the storage film (1) can be inserted from the casing (2) into the storage film scanning device.

5. Storage film feed according to claim 4, the additional slider (20) of which has a flat lower side and / or the additional slider (20) of which slides the storage film (1) into the passage gap (9) by means of a motor drive once the slider (4) is resting on the stop piece (6) and / or in which the additional slider (20) is moved back into a starting position by means of a motor drive when the storage film (1) is collected by a draw-in (8).

6. Storage film feed according to one of claims 1 to 5, wherein the slider (4) and the stop piece (6) are connected to a housing (5) of the storage film scanning device in a light proof manner and / or wherein a lateral contact element is fastened to the stop piece (6) or the housing (5) for laterally guiding the ecasing (2).

7. Storage film feed according to one of claims 1 to 6, wherein the inner surfaces of the passage gap (9) are provided with a soft, low-friction coating and / or wherein the clear width of the passage gap (9) is greater than the thickness of the storage film (1) and the inner surfaces with respect to the storage film (1) preferably have a minimum distance of 0.3 mm during insertion of the storage film (1).

8. Storage film scanning device having a storage film feed according to one of the preceding claims.

9. Use of an storage film (1) having a flexible casing (2) open on one front side in a storage film scanning device according to claim 8, wherein the storing plate (1) has at least one wear-resistant cover layer and / or wherein the static friction coefficients of the storage film (1) in the casing (2) are lower than the static friction coefficients of the casing (2) with respect to the stop piece (6) and the slider (4).