JP2010186187A - Cassette for radiograph - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cassette that has a cassette structure optimal for columnar crystal grown by a vapor phase growth method, reduces an external influence acting on the cassette, and suppresses generation of refuse or the like causing an image defect. <P>SOLUTION: This cassette includes a front member 10 and a back member 20, stores a sheet-like recording medium 28 that is formed by the vapor phase growth method and is made of the columnar crystal of a thickness of the range of 20 μm to 2 mm. The front member can be attached/detached from the back member in a substantially the same direction as the growing direction of the columnar crystal. A always non-contact buffer member 29 is arranged between the front member and the recording medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cassette containing a stimulable phosphor suitable for radiography.

  2. Description of the Related Art Conventionally, a cassette in which a radiographic image is taken with respect to a cassette in which a stimulable phosphor is accommodated and a radiographic image is read from the stimulable phosphor after photographing has been used for medical purposes (Patent Documents 1 to 5 below). 6). In such a conventional cassette, a coating type, for example, BaFI phosphor has been used as the stimulable phosphor.

  As a cassette structure using a coating type (BaFI) phosphor, various methods have been put into practical use as shown below. In the following Patent Document 1, a method is adopted in which a part of the cassette tip is opened and a flexible recording medium is taken out with a suction cup. In the following Patent Document 2, a cassette structure similar to that in the above Patent Document 1 is adopted, and a recording medium that is considered to be higher in rigidity than that is conveyed by a roller. In Patent Document 3 below, a method of fully opening the front plate around the hinge is adopted.

  Patent Document 4 below employs a configuration in which a detachable cap and a relatively rigid recording medium are integrated and the recording medium is taken in and out of the cassette body. In the following Patent Document 5, the front plate and the back plate are completely separated, and the connection between them is performed by opening and closing the mechanical locking means. In the following Patent Document 5, a configuration is adopted in which the front plate and the back plate are completely separated, the coupling between the two is performed by the attractive force of the magnet, and the separation is performed by bending.

  The coating type (BaFI) phosphor does not pose a major problem from the viewpoint of image quality maintenance and durability (image deterioration), regardless of which of the various cassette structures described above is adopted.

  Also, in the cassette of Patent Document 2 below, a nonwoven fabric is pasted as a cushioning material on the flat plate portion facing the image recording layer of the radiation image recording medium, and the nonwoven fabric is not frayed, so there is no waste as an image. However, when the recording medium is inserted into the cassette, the nonwoven fabric may be cut off at the edge of the recording medium, and dust may be generated. Depending on repeated use, there is a problem of generating dust and causing image defects. It was.

On the other hand, in recent years, a phosphor obtained by growing a columnar crystal to a predetermined thickness by a vapor phase growth method has attracted attention from the viewpoint of obtaining high sensitivity with respect to a coating type phosphor. If the columnar crystals obtained by vapor phase growth are thin films at the nanometer (nm) level, the phosphor has the same strength as the coating type, but a phosphor having advantages such as high sensitivity is put to practical use in the CR system. The present inventors have found that a certain degree of film thickness is required, and that columnar crystals formed by vapor phase growth tend to be brittle and easily damaged by external force or the like. Therefore, it is not preferable that the recording medium be deformed or subjected to an impact force when it is transported or handled during shooting, and it is not preferable to take the recording medium after it has been shot and the image information has been read. Further, it is not preferable that an impact force acts on the recording medium when it is inserted again (returned to the cassette).
JP 2000-257663 A JP 05-313267 A Japanese Patent Laid-Open No. 07-120854 Japanese Patent Laid-Open No. 11-271895 JP 2002-156716 A U.S. Patent Specification 4,961,000

  The present invention is a cassette structure that is optimal for columnar crystals grown by a vapor phase growth method in view of the above-described problems of the prior art, such as dust that can mitigate the effects of external forces acting on the cassette and cause image defects. An object is to provide a cassette capable of suppressing the occurrence.

  In order to achieve the above object, the present inventors have conducted extensive research and examinations, and in order to put a phosphor composed of columnar crystals by a vapor phase growth method into practical use as a recording medium, the film thickness is about 20 μm to 2 mm. On the other hand, if the columnar crystal formed by the vapor phase growth method has a thickness in the range of 20 μm to 2 mm, it is fragile to external forces such as bending and impact, and the growth direction is substantially shorter than the growth direction of the columnar crystal. Obtaining knowledge that external force is applied in the direction perpendicular to each other, it is easy to break, and generally the distance between the recording medium and the front member should be small, but the CR system by the present inventors etc. In the examination, the knowledge that the image quality deteriorates at 2 mm or more was obtained, and the present invention has been made based on this knowledge.

  That is, the cassette according to the present invention is composed of a front member and a back member, accommodates a sheet-like recording medium made of a columnar crystal having a thickness in the range of 20 μm to 2 mm formed by a vapor phase growth method, and the columnar crystal The front member and the back member are configured to be relatively detachable in substantially the same direction as the growth direction, and a non-contact buffer member is always disposed between the front member and the recording medium. It is characterized by.

  According to this cassette, the front member and the back member, for example, read image information in substantially the same direction as the growth direction of the columnar crystals by the vapor phase growth method in the thickness range of 20 μm to 2 mm constituting the sheet-like recording medium. For example, even if an external force is applied to the sheet-shaped recording medium due to such desorption, it is applied in substantially the same direction as the growth direction of the columnar crystals and between the front member and the recording medium. Since the shock absorbing member is arranged on the surface to absorb and relieve the impact caused by the external force, the columnar crystal becomes difficult to break. Further, since the buffer member is not in contact with the recording medium at all times, peeling electrification hardly occurs when the recording medium is taken out, and there is no suction of dust due to static electricity, and no dust is generated from the buffer member itself. It is possible to prevent problems such as breakage or scratching of the recording medium without applying stress to the recording medium. In this way, it is possible to realize a cassette having an optimum cassette structure that suppresses suction / generation of dust or the like that causes image defects and that is least stressed on a recording medium using columnar crystals grown by a vapor phase growth method.

  In the cassette, the sheet-like recording medium has a sheet-like image recording unit in which a crystal is grown in a direction substantially perpendicular to the sheet surface by the vapor phase growth method on one side of a rectangular sheet, It is preferable that it is integrated with the back member side on the opposite surface of the recording unit, and the front member is configured to be detachable from the back member and the sheet-like recording medium. Thereby, since the sheet-like recording medium is integrated with the back member side on the opposite surface of the columnar crystal by the vapor phase growth method, the sheet-like image recording portion is hardly affected by the integration.

  Further, it is preferable that the back member and the sheet-like recording medium are joined so as to be relatively movable. Thereby, even if the cassette or the back plate is deformed by an external force, the sheet-like recording medium moves relative to the back member, so that the transmission of the external force is relaxed. For this reason, the recording medium using the columnar crystal grown by the vapor phase growth method is hardly broken.

  Further, it is preferable that a gap between the recording medium and the front member is in a range of 0.5 to 2 mm, and the buffer member is thinner than the gap. If the gap between the recording medium and the front member is 0.5 mm or more, the non-contact of the buffer member can be maintained relatively easily, and if it is 2 mm or less, the image quality does not deteriorate. Moreover, it is preferable that the said buffer member consists of a nonwoven fabric.

  According to the cassette of the present invention, the cassette structure is optimal for the columnar crystal grown by the vapor phase growth method, the influence of external force acting on the cassette can be mitigated, and generation of dust or the like that causes image defects can be suppressed.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a state where a front member (A) and a back member (B) of a radiographic imaging cassette according to the present embodiment are separated. FIG. 2 is a cross-sectional view (A) schematically showing a cross-section of the cassette in which the front member and the back member of FIG. 1 are combined, and an enlarged cross-sectional view (B) of the main part of the cassette. FIG. 3 is an internal view (A) of the back member and a side view (B) showing a cross section of the main part for explaining the locking mechanism of the cassette of FIG. 4 is a cross-sectional view of the cassette showing the states (A) to (H) of the locking mechanism of FIG. FIG. 5 is a schematic cross-sectional view (A) of the stimulable phosphor sheet housed in the radiographic imaging cassette of FIG. 1 and an enlarged cross-sectional view (B) near the surface of the sheet-like image recording unit.

  As shown in FIGS. 1A and 1B, a radiographic imaging cassette (hereinafter also simply referred to as “cassette”) 1 is a front member 10 and a back disposed so as to face the front member 10. The member 20 is formed in a thin rectangular shape as a whole, and is configured so that the stimulable phosphor sheet 28 can be accommodated in the internal space while being fixed to the support plate 27 on the back member 20 side. . The front member 10 and the back member 20 are detachable.

  The cassette 1 is irradiated with radiation from the front member 10 side to perform radiography, and can accumulate and record a radiographic image on the stored stimulable phosphor sheet 28. That is, as shown in FIG. 5A, the stimulable phosphor sheet 28 has a stimulable phosphor layer 28a made of a stimulable phosphor having CsBr as a base and formed on a support plate 27, for example. The phosphor layer 28a constitutes a sheet-like image recording unit.

  The stimulable phosphor layer 28a is formed by vapor deposition by vapor deposition, and is formed of columnar crystals by vapor deposition as shown in FIG. 5B. The growth direction V of the columnar crystals is the stimulable phosphor. The sheet 28 extends toward the surface 28b in the thickness direction. The average diameter of the columnar crystals is about 3 μm. The thickness t of the stimulable phosphor layer 28a is in the range of 20 μm to 2 mm.

  It should be noted that the size of the columnar crystal of the stimulable phosphor, for example, the size of the columnar crystal of CsBr can be controlled by more precisely controlling the formation of the columnar crystal by the vapor phase growth method, and the modulation transfer function ( MTF) can be improved, both high sensitivity and high sharpness can be achieved, and radiation images with better image quality can be stored and recorded.

  As shown in FIG. 1A, the front member 10 has a frame member 11 having an outer frame having a frame 17 on the short side and a frame 18 on the long side, and the front member 10 inscribed in front of the inner surface of the frame member 11. A face plate 13. As shown in FIG. 2A, the frame member 11 includes a frame front surface portion 114 facing the front surface side, a frame side surface portion 110 bent from the end portion of the frame front surface portion 114 substantially at a right angle toward the rear surface side, and a frame side surface. A frame rear surface portion 111 bent further inward in the width direction substantially perpendicularly from the end portion of the portion 110, and an inclined surface portion 112 bent toward the frame front surface portion 114 at a predetermined angle from the end portion of the frame rear surface portion 111, Have Further, a light-shielding protrusion 115 that protrudes in the same direction as the frame side surface portion 110 is provided on the back surface of the frame front surface portion 114.

  Further, as shown in FIG. 2A, a recess 12 is formed inside the frame member 11 by a space surrounded by the frame front surface portion 114, the frame side surface portion 110, the inclined surface portion 112, and the light shielding protrusion 115. The

  Further, as shown in FIGS. 2A and 2B, a planar cushioning material 29 made of, for example, a nonwoven fabric is disposed on the inner surface side (back member 20 side) of the front plate 13 of the frame member 11.

  Further, the frame rear surface portion 111 and the inclined surface portion 112 of the long side frame 18 have a plurality of cuts 15 corresponding to the plurality of lock claws on the back member 20 side as shown in FIGS. Is formed. Further, as shown in FIGS. 1 (A), 4 (B), and 4 (D), a notch portion 14 is provided at the approximate center in the longitudinal direction of the frame side surface 110 of the frame 17 on one short side. The grip concave portions 16a are respectively formed on the end portions in the width direction of the side surface portions 110 of both frames.

  As shown in FIGS. 1B and 2A, the back member 20 includes a back member main body 21, a stimulable phosphor sheet 28, and a support plate 27 that supports the stimulable phosphor sheet 28. . The back member main body 21 has a back member rear surface portion 210 and a back member side surface portion 211 bent from the back member rear surface portion 210 to the front surface side at a substantially right angle. In addition, an inner wall 213 and a rib 214 projecting in the same direction as the back member side surface portion 211 are provided on the front surface of the back member rear surface portion 210. Further, as shown in FIG. 2A, the recess 22 is formed in a space surrounded by the back member rear surface portion 210, the back member side surface portion 211, and the inner wall 213.

  As shown in FIGS. 1B and 3A, an insertion hole 34 is formed in the back member side surface portion 211 on one end side in the short side direction of the cassette 1 so as to correspond to the notch portion 14 on the front member 10 side. Has been. Further, openings 31 a, 31 b, 31 c, and 31 d are formed on the end side in the longitudinal direction of the back member side surface portion 211, and openings 33 a and 33 b are formed on the width direction end portion side of the back member side surface portion 211. Yes.

For example, a back plate 23 having a configuration in which a lead foil is coated with a PET film is fixed to the rib 214 of the back member 20. A support plate 27 is bonded to the back plate 23 at a surface 27a opposite to the stimulable phosphor layer 28a shown in FIG. On the side, the stimulable phosphor layer 28a formed by the vapor phase growth method (evaporation) as described above is located.
Thus, the stimulable phosphor sheet 28 is accommodated on the back member 20 side.

In the cassette 1 described above, when the back member 20 and the front member 10 are combined as shown in FIG. 2A, the light shielding protrusion 115 of the front member 10 enters the recess 22 of the back member 20 and the recess 12 of the front member 10. The back member side surface portion 211 of the back member 20 enters. With such a structure, the back member 20 and the front member 10 are integrally combined to form the cassette 1, and light is blocked so that external light does not reach the stimulable phosphor sheet 28.
Further, if the concave portion 12 of the front member 10 or the concave portion 22 of the back member 20 is provided with, for example, velvet or sponge so that the back member 20 and the front member 10 are more closely attached, the light shielding property can be further improved.

  Further, as shown in FIG. 2B, when the front member 10 and the back member 20 are combined, the distance between the front plate 13 on the front member 10 side and the stimulable phosphor layer 28a on the back member 20 side is 0. A gap g in the range of 5 to 2 mm is formed. The flat cushioning material 29 made of a nonwoven fabric or the like is positioned on the front member 10 side in the gap g, and a gap 29a is formed with respect to the stimulable phosphor layer 28a of the stimulable phosphor sheet 28. . Therefore, the buffer material 29 is not in contact with the stimulable phosphor layer 28a at all times. In addition, the nonwoven fabric as the buffer material 29 can use various types, for example, a suede type, a velor type, and a velor type (raised).

  Further, since the back member main body 21 is attracted and held by the magnetic force of the magnet in a radiographic image reading apparatus to be described later, the back member main body 21 itself is used as a magnetic part so that it can be attracted to the magnet by the magnetic force. It is preferable to form by such as. Alternatively, the back member main body 21 may be formed of a normal plastic, and a magnetic sheet (not shown) such as iron foil may be provided on the back surface 24 of the back member 20 as a magnetic part. Further, a magnetic part may be applied to the back surface 24 of the back member 20 by applying a magnetic substance.

  As described above, the front member 10 and the back member 20 are combined and detachable, but usually radiography is performed in the combined state as shown in FIG. When the front member 10 and the back member 20 are separated and united, the front member 10 and the back member are aligned in substantially the same direction as the growth direction of the columnar crystals of the stimulable phosphor sheet 28 as shown in FIGS. The member 20 is separated and united so that the planes are relatively apart from each other and approach each other. Accordingly, when the front member 10 and the back member 20 are detached, even if an external force is applied to the stimulable phosphor sheet 28, it is not in the direction substantially perpendicular to the columnar crystal growth direction but in the column crystal growth direction. Since they are applied in the same direction, the columnar crystals are difficult to break.

  Further, a buffer material 29 made of a nonwoven fabric or the like is not in contact with the stimulable phosphor layer 28a at all times in the gap g between the front plate 13 on the front member 10 side and the stimulable phosphor layer 28a on the back member 20 side. Therefore, even if an impact or the like is applied to the cassette 1 by an external force, the impact can be absorbed and relaxed, the columnar crystals are difficult to break, and peeling electrification occurs when the stimulable phosphor sheet 28 is taken out. It is difficult to attract dust due to static electricity, no dust is generated from the buffer member 29 itself, and it is possible to prevent problems such as damage or damage to the stimulable phosphor sheet 28 without applying stress to the stimulable phosphor sheet 28. . When the recording medium is taken out, the recording medium can be prevented from being damaged or damaged without being stressed.

  As described above, there is provided a cassette having an optimum cassette structure that suppresses suction / generation of dust and the like that causes image defects and has the least stress on the stimulable phosphor sheet using the columnar crystal grown by the vapor phase growth method. realizable.

Next, the locking mechanism of the cassette 1 will be described with reference to FIGS. In order to keep the front member 10 and the back member 20 in a combined state, the cassette 1 includes a lock mechanism.
As a locking mechanism of the cassette 1, the front member 10 is formed with a plurality of notches 15 for locking claws (FIGS. 4F and 4H), and the back member 20 is used as a locked portion. A first connecting member 35, a second connecting member 36 and a pinion 37 having a plurality of lock claws are provided.

  As shown in FIG. 3A, the first connecting member 35 includes a first horizontal member 35a and a first middle member that protrudes inward in the longitudinal direction of the back member 20 from the middle right side of the first horizontal member 35a. 35b, and a first left member 35c that protrudes inward in the longitudinal direction of the back member 20 from the left end portion of the first horizontal member 35a.

  The second connecting member 36 includes a second horizontal member 36a, a second middle member 36b projecting from the middle left side of the second horizontal member 36a to the side opposite to the first middle member 35b, and a second horizontal member 35a. And a second left member 36c that protrudes inward in the longitudinal direction of the back member 20 from the right end portion thereof.

  The front end portion of the first middle member 35b and the front end portion of the second middle member 36b are opposed to each other with the pinion 37 provided substantially at the center of the back member 20, and a rack portion 35B provided on each front end side surface. 36B are engaged with the pinion 37, whereby the first connecting member 35 and the second connecting member 36 are connected via the pinion 37.

  In addition, lock claws 30 a and 30 b as locked portions are provided in the vicinity of the end portions of the first lateral member 35 a of the first connecting member 35 so as to protrude from the back member side surface portion 211. Further, a lock claw 32a as a slide member is provided on the outer side surface of the first left member 35c.

  Further, as shown in FIG. 3A, two coil springs 38a each having one end fixed to the first connecting member 35 and the other end fixed to the inner surface side of the back member side surface portion 211 are provided. Due to this coil spring 38a, the first connecting member 35 is always subjected to an urging force to move in the direction of the arrow Q1.

  Further, a push latch portion 39 is provided between the first connecting member 35 and the back member side surface portion 211 in which the insertion hole 34 is formed. The push latch portion 39 has a slide plate 50 protruding from the back member side surface portion 211 as shown in FIGS. 1B and 3A, and is always biased in the direction of the arrow Q1 by a spring (not shown). Is receiving.

  In addition, lock claws 30c and 30d serving as locked portions are provided near the end portion of the second lateral member 36a of the second connecting member 36 so as to protrude from the back member side surface portion 211. Yes. Further, a lock claw 32b as a slide member is provided on the outer side surface of the second right member 36c.

  In the present embodiment, the lock claws 30a, 30b, 32a provided on the first connecting member 35 are interlocked, while the lock claws 30c, 30d, 32b provided on the second connecting member 36 are interlocked. Further, since the first connecting member 35 and the second connecting member 36 are interlocked by the operation of the rack portions 35B and 36B and the pinion 37 provided respectively, all the lock claws 30a, 30b, 30c, 30d, 32a, and 32b are interlocked.

  In the cassette 1 according to the present embodiment, the notch portion 14 of the front member 10 is in a positional relationship corresponding to the insertion hole 34 of the back member 20 when the front member 10 and the back member 20 are combined, and is inserted at the notch portion 14. A method (push latch method) in which the state of the lock mechanism (lock on state / lock off state) is switched each time the member is inserted and the slide plate 50 is slid to push the push latch portion 39 is employed. The push latch method is well known as a mechanism used when a ballpoint pen core is taken in and out of the ballpoint pen exterior.

  Next, the lock on / off operation by the above-described lock mechanism will be described with reference to FIGS.

  In the lock-on state, the front ends of the locking claws 30a, 30b, 30c, and 30d that are locked portions protrude outward from the openings 31a, 31b, 31c, and 31d of the back member side surface 211, FIG. 4A shows a state in which it has entered between the portion 114 and the inward surface 113 of the inclined surface portion 112. At this time, the push latch portion 39 is in the state of FIG. 4B in contact with the back member side surface portion 211 and away from the first connecting member 35. Further, the lock claws 32a and 32b which are the slide portions are in the state of FIGS. 4E and 4F which have entered between the frame front surface portion 114 of the front member 10 and the inward surface 113 of the inclined surface portion 112.

  In such a lock-on state, when the insertion member is inserted only once in the arrow direction P from the notch portion 14 and the slide plate 50 of the push latch portion 39 is pressed, the push latch portion 39 becomes the first connecting member. 35 is pushed in the arrow direction Q2. Then, the first connecting member 35 moves by a predetermined distance in the arrow direction Q2, and the push latch portion 39 stops, and the state shown in FIG. At this time, the lock claws 30a and 30b of the first connecting member 35 are in the state of FIG. The states of FIGS. 4C and 4D are the lock-off state of the lock mechanism.

  When the first connecting member 35 moves in the direction of the arrow Q2, the second connecting member 36 also moves and stops in the direction of the arrow R2 by the same distance, so that the lock claws 30c of the second connecting member 36, The leading end of 30d enters the inside of the back member side surface portion 211, and the lock-off state of FIG.

  At this time, the locking claw 32a of the connecting member 35 and the locking claw 32b of the connecting member 36 are also moved in the direction of the arrow Q2 by the same distance in the direction of the arrow Q2 and stopped. The state (H) is obtained. In this state, the lock claws 32a and 32b are aligned with the notches 15 (openings provided in the frame rear surface portion 111 and the frame inclined surface portion 112), so that the lock claws 32a and 32b may come out of the notches 15. it can. That is, the back member 20 can be separated from the front member 10. The states of FIGS. 4G and 4H are the lock-off state of the lock mechanism.

  The front member 10 and the back member 20 can be separated in the lock-off state of the lock mechanism as shown in FIGS. 4C, 4D, 4G, and 4H, and the push latch portion 39 is not pressed. As long as this lock-off state continues.

  4C and 4D, when the insertion member presses the slide plate 50 of the push latch portion 39 through the notch portion 14, the push latch portion 39 returns to the arrow Q1 direction. The first connecting member 35 moves by a predetermined distance in the direction of the arrow Q1 and stops, and the state shown in FIG. At this time, the tips of the lock claws 30a and 30b protrude outward from the openings 31a and 31b, and enter between the frame front surface portion 114 of the front member 10 and the inward surface 113 of the inclined surface portion 112, and the lock shown in FIG. Turns on. At this time, the lock claws 32a and 32b are also interlocked and moved in the direction of the arrow Q1 by the same distance through the openings 33a and 33b and stopped, and the lock-on state as shown in FIGS. Become.

  When the first connecting member 35 moves in the direction of the arrow Q1, the second connecting member 36 also stops by moving the same distance in the direction of the arrow R1, and the tips of the lock claws 30c, 30d are opened to the opening 31c, It protrudes outside 31d and enters between the frame front surface portion 114 of the front member 10 and the inward surface 113 of the inclined surface portion 112, and the lock-on state of FIG. Thus, unless the back member 20 is locked and fixed to the front member 10 and the push latch portion 39 is not pressed, this lock-on state is continued and maintained.

  As described above, in the cassette 1 according to the present embodiment, the state in which the back member 20 is locked to the front member 10 by the push latch mechanism that switches each time the lock-on state / lock-off state is pressed can be separated from the state. Can be easily switched. Further, the lock mechanism of the cassette 1 is brought into the lock-off state by the push latch mechanism, the front member 10 and the back member 20 are separated in a later-described radiographic image reading apparatus, the stimulable phosphor sheet 28 is exposed, and the stimulable fluorescence is exposed. The radiation image information stored and recorded in the body sheet 28 can be read.

  Next, a modification of the support structure of the stimulable phosphor sheet 28 in the cassette will be described with reference to FIG. FIG. 6 is a cross-sectional view (A) showing a modification of the cassette of FIG. 2, a cross-sectional view (B) showing a state in which an external force is applied to the front member, and a cross-sectional view showing a state in which the back member is deformed by applying an external force ( C), FIG. 6D schematically showing the deformation of the double-sided tape as the joining means in FIG. 6C, and FIG. 6C schematically showing the deformation of the elastic adhesive as the joining means in FIG. (E) shown in FIG.

  As shown in FIG. 6A, the back member 20 and the stimulable phosphor sheet 28 are joined in such a manner that they can be moved relative to each other. Examples of the joining means include a magnet, an elastic adhesive, and a double-sided tape. For example, a magnet 20a is provided on the back member 20 side, and an iron foil 20f that adsorbs the magnet 20a is provided on the storage phosphor sheet 28 side. The joint 20c on the pedestal 20b formed integrally with the back member 20 is made of an elastic adhesive or a double-sided tape having an adhesive on both sides, so that the back member 20 and the stimulable phosphor sheet 28 are connected to each other. Relative movement is possible.

  When the deflection direction (deformation direction) when the housing receives an external force is specified by the shape of the cassette housing, a combination of different joining means such as the magnet 20a and the joining portion 20c as described above is used. Of course, the same joining means (for example, all elastic adhesives) may be used.

  As shown in FIG. 6A, a planar cushioning material 29 made of a nonwoven fabric or the like is attached to the inner surface of the front member 10 of the cassette. The buffer material 29 is always in a non-contact state with respect to the surface of the stimulable phosphor sheet 28.

When the cassette of FIG. 6A is deformed by applying an external force to the cassette on the front member 10 side as shown in FIG. 6B, the front member 10 and the stimulable phosphor sheet 28 are relatively close to each other. Since there is a buffer material 29 between the two, the two do not come into contact with each other, the external force is absorbed and relaxed, and stress is hardly transmitted to the stimulable phosphor sheet 28, and the influence of the external force does not occur.
On the other hand, since the back member 20 is not deformed, the stimulable phosphor sheet 28 is not affected by the external force from the back member 20 side.

  Further, as shown in FIG. 6C, even if the front member 10 and the back member 20 of the cassette are deformed by applying an external force, the external force is applied by the buffer material 29 between the front member 10 and the stimulable phosphor sheet 28. Is absorbed and relaxed, so that no stress is applied to the stimulable phosphor sheet 28 and the influence of external force does not occur. On the other hand, the back member 20 and the stimulable phosphor sheet 28 move relative to each other by the magnet 20a and the joint portion 20c, so that the transmission of external force to the stimulable phosphor sheet 28 is alleviated, and external force is applied to the stimulable phosphor sheet 28. The effect is less likely to occur. In this way, the stimulable phosphor sheet 28 is difficult to break.

  When the cassette is deformed as shown in FIG. 6 (C), when the joining means is compared in terms of deformation followability, the elastic adhesive is most preferable among the magnet, the double-sided tape, and the elastic adhesive, and then the double-sided. Tape is preferred.

  That is, when the joint portion 20c in FIG. 6C is the double-sided tape 20d as shown in FIG. 6D, the double-sided tape 20d is deformed mainly in the direction X as shown by the broken line in the figure, and the back member 20 Follow the deformation. On the other hand, when the joint portion 20c is an elastic adhesive 20e as shown in FIG. 6E, the elastic adhesive 20e is deformed while changing its volume in the direction X and the direction Y as shown by the broken line in the figure. Follow the deformation. Further, in the case of a magnet, only the stimulable phosphor sheet 28 is slid in the direction X and there is no function for the direction Y.

  From the above, the elastic adhesive 20e can follow and deform in both the direction X and the direction Y, and the follow-up range becomes wider than the double-sided tape 20d that is deformed in the direction X and hardly deformed in the direction Y. FIG. Even if the back member is deformed so as to have the radius R1, the stimulable phosphor sheet 28 is not deformed so much and the elastic deformation is absorbed by the elastic adhesive 20e. Therefore, the radius R2 larger than the radius R1 is absorbed. Preferably, the storage phosphor sheet 28 is deformed so that (R2> R1) is not deformed.

  Further, the double-sided tape 20d has a wider follow-up range than the magnet, and the deformation radius R2 of the stimulable phosphor sheet 28 is larger than that of the magnet when the deformation radius R1 of the back member 20 is constant. The sheet 28 is difficult to deform.

  Of the adhesives, relatively hard ones such as instantaneous adhesives are not preferable because the follow-up range is very narrow, the deformation radius R2≈the deformation radius R1, and the stimulable phosphor sheet 28 is easily deformed.

  Next, another modification of the support structure of the stimulable phosphor sheet 28 in the cassette will be described with reference to FIG. FIG. 10 is a cross-sectional view (A) showing another modification of the cassette of FIG. 2, and a cross-sectional view (B) showing a state where the back member is deformed by applying an external force.

  The joining means of the cassette back member 20 and the stimulable phosphor sheet 28 in FIG. 6 is configured to keep the joining area constant when the cassette is subjected to external force and the back member is deformed. The means is configured such that when the back member 20 and the stimulable phosphor sheet 28 move relative to each other, the bonding area is reduced.

  That is, as shown in FIG. 10A, the back member 20 and the stimulable phosphor sheet 28 are composed of a magnet 20g provided on the back member 20 side and an iron foil 20f provided on the stimulable phosphor sheet 28 side. Joined by adsorption. Further, the back member 20 is integrally formed with the back member 20 so that a rib 20 h as a position restricting portion of the stimulable phosphor sheet 28 is close to the end of the stimulable phosphor sheet 28.

  As shown in FIG. 10B, when the back member 20 is deformed, the attracting force (magnetic force) of the magnet 20g to the iron foil 20f is separated so that the magnet 20g and the iron foil 20f are in a substantially point contact state at the end 20i. ) Is set.

  When the cassette receives an external force and the back member 20 is deformed, as shown in FIG. 10B, the magnet 20g moves relative to the iron foil 20f of the stimulable phosphor sheet 28 and moves away from the iron foil 20f. The part 20i is almost in point contact with the iron foil 20f. For this reason, even if the back member 20 is deformed, the deformation is not transmitted to the stimulable phosphor sheet 28 side. Therefore, the stimulable phosphor sheet 28 can maintain a flat surface and is not deformed.

  Further, as shown in FIG. 10B, even when the front member 10 and the stimulable phosphor sheet 28 are relatively close to each other, the cushioning material 29 such as a nonwoven fabric between them does not come into contact with each other and external force is applied. Is absorbed and relaxed, and almost no external force is applied to the stimulable phosphor sheet 28, and the influence of the external force does not occur.

  Further, when the deformation of the back member 20 is repeated, the position of the stimulable phosphor sheet 28 is regulated by the rib 20 h in the vicinity of the end portion thereof, so that the position of the stimulable phosphor sheet 28 is predetermined with respect to the back member 20. Can be kept within range.

  As described above, the configuration of FIG. 10 can maintain the flat surface of the stimulable phosphor sheet 28 and is preferable to FIG. 6. However, the attractive force (magnetic force) of the magnet 20g to the iron foil 20f is reduced, and the back member 20 Since the relative position of the storage phosphor sheet 28 may change, the position is regulated by the rib 20 h provided on the back member 20 side as shown in FIG. 10 to prevent the relative position from changing.

  Next, a radiographic image reading apparatus which takes in the above-described radiographic imaging cassette 1 and separates the front member 10 and the back member 20 and reads the radiographic image stored and recorded in the stimulable phosphor sheet 28 by radiography. This will be described with reference to FIGS.

  7 is a side view showing a schematic configuration of the radiographic image reading apparatus, FIG. 8 is a schematic plan view of the radiographic image reading apparatus of FIG. 7, and FIG. 9 is an explanatory view of the cassette separating operation of the radiographic image reading apparatus of FIG. It is a principal part side view for doing.

  As shown in FIG. 7, the apparatus main body 2 includes an insertion port 3 for the cassette 1, a discharge port 4 for the cassette 1, and two units, a cassette insertion / discharge unit 2a and a conveyance reading unit 2b. The cassette insertion / ejection unit 2a has a structure that can be easily detached from the conveyance reading unit 2b. Further, an anti-vibration rubber 73 is disposed between the conveyance reading unit 2b and the cassette insertion / ejection unit 2a, so that vibration when inserting or ejecting the cassette is not easily transmitted to the conveyance reading unit 2b.

  Further, the sub-scanning unit 500 and the cassette transport mechanism 40 in the transport reading unit 2 b are constructed on the same substrate 710. By disposing the vibration isolating rubber 720 between the substrate 710 and the bottom plate 700, a vibration isolating structure that does not propagate the vibration of the cassette insertion / ejection unit 2b to the sub-scanning unit 500 is realized. Further, an anti-vibration rubber 74 is disposed between the upper end of the sub-scanning unit 500 and an apparatus frame (not shown), and the anti-vibration structure for the sub-scanning unit 500 is reinforced.

  With such an anti-vibration structure, a cassette is inserted into the insertion port 3 and a cassette is removed from the discharge port 4 while the image information is being read from the stimulable phosphor sheet 28 by the transport reading unit 2b. Even if the main body 2 is vibrated, noise due to vibration can be prevented from occurring in the read image information. In addition, since the sub-scanning unit 500 and the transport mechanism 40 are constructed on the same substrate 710, when the back member 20 is delivered from the transport mechanism 40 to the sub-scanning unit 500, the delivery position is not blurred. Thereby, the separation / merging work of the front member 10 and the back member 20 can be stably and accurately performed.

  Next, the operation of the radiation image reading apparatus will be described. The cassette 1 is assumed to be a half-cut cassette, but is not limited to this.

  The cassette 1 containing the stimulable phosphor sheet 28 on which the radiographic image has been taken is inserted into the insertion port 3 in the direction of the arrow A1 as shown in FIG. At this time, the cassette 1 is inserted so that the notch portion 14 and the insertion hole 34 of FIG. 1 are on the lower side, and the front plate 13 of the front member 10 faces obliquely downward. That is, the storage phosphor sheet 28 is inserted so that the reading surface faces obliquely downward. When the cassette 1 is inserted into the insertion port 3, the presence of the cassette 1 is recognized by a cassette detection sensor (not shown), and the cassette is moved to the center of the insertion port 3 by the width adjusting portion 47 arranged in the insertion port 3. It is justified.

  When the cassette 1 is brought close to the center of the insertion slot 3, the code storage element on the outer surface of the back member 20 and the position of the code reading unit 45 match, and the code recorded in the code storage element 200 is the code. It is read by the reading unit 45.

  When the code reading unit 45 reads the code correctly, the cassette size is detected from the read code, and adjustment is started according to the width of the transport mechanism 40 according to the cassette size. That is, the width adjusting portions 401a and 401b in FIG. 8 start moving in the direction of the arrow M in accordance with the size of the cassette 1.

  Next, the insertion roller 42 is operated to take the cassette 1 into the apparatus main body 2 in the direction of the arrow A2 along the dotted line a. The transport mechanism 40 is already waiting at the position of the dotted line a when the insertion roller 42 is operated, and receives the cassette 1 carried by the insertion roller 42 from the insertion port 3. When the cassette grips 402a, 402b on the lifting platform 402 (operating along the transport mechanism 40) catch the lower end of the cassette 1, the lifting platform 402 transports the cassette 1 along the transport mechanism 40 in the direction of arrow A2, Control is performed so that the upper end of the cassette 1 stops at a position indicated by an arrow Z as shown in FIG.

  When the cassette 1 stops at the position indicated by the arrow Z, the tips of the grip claws 403 a and 403 b are inserted into the recesses of the grip recess 16 a existing on the side surfaces 110 of both front members, and the front member 10 is moved relative to the transport mechanism 40. To a fixed state.

  The transport mechanism 40 has a rotation shaft 404, and can freely rotate and move at least within a range from a dotted line a to a dotted line c with the rotation shaft 404 as a rotation center. When the cassette 1 is taken into the apparatus main body 2 by the transport mechanism 40, the transport mechanism 40 rotates from the position of the dotted line a to the position of the dotted line c in the direction of the arrow A3 with the rotation shaft 404 as the rotation center. When the transport mechanism 40 rotates to the position of the dotted line c, the outer surface of the back member of the cassette 1 having a magnetic material is attracted to the magnet 540 by a magnetic force. At this time, since the back member 20 has appropriate flexibility, the flatness of the back member 20 follows that of the magnet 540 when adsorbed on the flat surface of the magnet 540.

  A lock pin (bar-shaped member) 402c for turning on / off the lock mechanism of the cassette 1 is disposed on the lifting platform 402, and the lock mechanism of the cassette 1 is turned on / off by the vertical movement of the lock pin 402c. can do. Further, the upper end (upper reference position Z) of the cassette 1 projects upward from the sub-scanning moving plate 530 of the sub-scanning unit 500 for the purpose of detecting the upper end or the side end of the cassette 1 during sub-scanning. Is configured to do.

When the back member 20 is attracted to the magnet 540, the lock pin 402c housed in the lifting platform 402 rises, and the lock pin is inserted into the insertion hole 34 of the back member 20 through the notch portion 14 of the front member 10 in FIG. The tip of 402c is inserted (see FIG. 8). With this operation, the lock of the cassette 1 in the lock-on state is released, and the state shifts to the lock-off state.
That is, the back member 20 and the front member 10 are separable. When the cassette 1 shifts to the lock-off state, the lock pin 402c is lowered and stored in the lifting platform 402 again.

  When the cassette 1 is unlocked and shifts to the lock-off state, the transport mechanism 40 rotates in the direction of the arrow A6 and stops at the retracted position (for example, the position of the dotted line b). By this operation, the back member 20 and the front member 10 are completely separated.

  As shown in FIG. 9, the back member 20 and the front member 10 are completely separated, the transport mechanism 40 stops at the retracted position, and the front member 10 is retracted from the back member 20 at a sufficient angle, so that the back member 20 is When the sub-scanning operation is performed, the back member 20 and the front member 10 can be prevented from interfering with each other.

  As described above, when the back member 20 is completely separated from the front member 10, the drive unit (not shown) is operated, and the back member 20 is conveyed (sub-scanned) in the direction of arrow A4 (upward). . During this sub-scanning operation, the stimulable phosphor sheet 28 is main-scanned in the direction perpendicular to the sub-scanning direction by the laser beam B emitted from the laser scanning unit 121.

  When laser light acts on the stimulable phosphor sheet 28, stimulating light (image information) proportional to the radiation energy accumulated in the stimulable phosphor sheet 28 is emitted, and this stimulating light passes through the light guide 122. After being collected in the condenser tube 123, the stimulated light is converted into an electrical signal by a photoelectric conversion element (not shown) such as a photomultiplier. The stimulated light converted into the electrical signal is subjected to predetermined signal processing as image data, and then output to another image output device (not shown).

  As described above, when the reading of the image information from the stimulable phosphor sheet 28 is completed, the drive unit (not shown) conveys the back member 20 in the direction of arrow A5 (downward) as shown in FIG. Start. While the back member 20 is conveyed in the direction of the arrow A5, the erasing light E is emitted from the erasing means 124, and the image information remaining on the stimulable phosphor sheet 28 is erased.

  Next, when the back member 20 is lowered to the position delivered to the magnet 540, the drive unit (not shown) stops the movement of the back member 20 by the sub-scanning unit 500. When the back member 20 stops at the position delivered to the magnet 540, the transport mechanism 40 that has been retracted to the retracted position rotates again to the position of the dotted line c, and the back member 20 and the front member 10 are united. When the back member 20 and the front member 10 are combined, the lock pin 402c housed in the lifting platform 402 is raised, and the tip of the lock pin 402c is inserted into the insertion hole 34 from the notch portion 14 of the front member 10. By this operation, the cassette 1 that has been in the lock-off state is locked and shifts to the lock-on state. That is, the back member 20 and the front member 10 cannot be separated. When the cassette 1 shifts to the lock-on state, the lock pin 402c is lowered and stored in the lifting platform 402 again.

  As described above, when the uniting operation of the back member 20 and the front member 10 is completed, the transport mechanism 40 again rotates in the direction of the arrow A6 to the position of the dotted line b and stops. When the transport mechanism 40 stops at the position of the dotted line b, the fixed state of the front member 10 by the grip claws 403a and 403b is released, and the cassette 1 becomes transportable on the transport mechanism 40.

  When the fixed state of the front member 10 is released, the lifting platform 402 transports the cassette 1 to the discharge port 4 along the transport mechanism 40 in the direction of arrow A7, and delivers the cassette 1 to the discharge roller 43. Upon receiving the cassette 1, the discharge roller 43 performs a discharge operation until the cassette 1 is completely discharged to the discharge port 4. When the cassette 1 is completely discharged to the discharge port 4, the transport mechanism 40 rotates and moves to the position of the dotted line a in the direction of the arrow A6, and shifts to a state where the next cassette 1 can be received.

  As described above, the storage phosphor sheet 28 in the cassette 1 is taken out in a non-contact manner by the image reading apparatus shown in FIGS. 7 to 9 to read the radiation image information, and is returned to the cassette and stored again. can do. According to the cassette 1 in the image reading apparatus, when the front member 10 and the back member 20 are separated, the front member is arranged in substantially the same direction as the thickness direction of the stimulable phosphor sheet 28 (columnar crystal growth direction). 10 and the back member 20 are separated from each other. For example, as shown in FIG. 7, the back member 20 of the cassette 1 moves from the position indicated by the dotted line a with respect to the front member 10 from the position of the dotted line a with the rotation axis 404 as the rotation center. When the front member 10 and the back member 20 are combined, they rotate in the same manner. Therefore, even if an external force is applied to the stimulable phosphor sheet 28, it is substantially in the columnar crystal growth direction. In addition to the orthogonal direction, it is added in the substantially same direction as the growth direction of the columnar crystals, so that the columnar crystals are difficult to break. In this manner, a cassette having a cassette structure optimum for a recording medium using columnar crystals grown by a vapor phase growth method can be used in the image reading apparatus shown in FIGS.

  Further, as shown in FIG. 2 (B), since the buffer material 29 is always arranged in a non-contact manner with respect to the stimulable phosphor layer 28a in the gap g in the cassette 1, the shock due to external force can be absorbed and reduced. The columnar crystals are not easily broken without applying stress to the fluorescent phosphor sheet 28, and the storage phosphor sheet 28 in the cassette 1 is taken out by the image reading device shown in FIGS. Next, even if it is operated so as to be returned to the cassette and re-stored, there is almost no generation of static electricity due to peeling electrification, dust is not sucked, dust is not generated from the buffer member 29, dust is sucked and generated, etc. It is possible to prevent image defects caused by the above.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, the number of the lock claws can be changed as appropriate. For example, in FIG. 3A, one lock claw may be added to the vertical side surface and a pair may be provided on the vertical side surface.

  Moreover, as the stimulable phosphor of the stimulable phosphor sheet 28, CsBr is used in the present embodiment, but the present invention is not limited to this, and other stimulable phosphors may be used. An accumulative phosphor based on an alkali halide represented by the following general formula (1) can be used. These stimulable phosphors can be formed into columnar crystals by vapor phase growth methods such as vapor deposition, sputtering, CVD, and ion plating.

The general ^{formula: M 1 X · aM 2 X} '2 · bM 3 X "3: eA (1)
In the above formula (1), M ¹ is at least one alkali metal atom selected from Na, K, Rb and Cs atoms, and M ² is Be, Mg, Ca, Sr, Ba, Zn, It is at least one divalent metal atom selected from Cd, Cu and Ni atoms, and M ³ is Sc, Y, La, Ce, Pr, Nd, Pm.
, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Al, Ga, and In, at least one trivalent metal atom, X, X ′, X ″ Is at least one halogen atom selected from F, C1, Br and 1 atoms, and A is Eu, Tb, In, Cs, Ce, Tm, Dy, Pr, Ho, Nd, Yb, Er , Gd, Lu, Sm, Y, Tl, Na, Ag, Cu and Mg are at least one metal atom, and a, b and e are 0 ≦ a <0. 5, 0 ≦ b <0.5, 0 ≦ b <0.5, 0 <e ≦ 0.2.

FIG. 1 is a perspective view showing a state where a front member (A) and a back member (B) of a radiographic imaging cassette according to the present embodiment are separated. It is sectional drawing (A) which shows typically the cross section of the cassette which the front member and back member of FIG. 1 united, and the expanded sectional view (B) of a cassette principal part. It is the inner side figure (A) of the back member for demonstrating the locking mechanism of the cassette of FIG. 1, and the side view (B) which shows the principal part cross section. It is sectional drawing of a cassette which shows each state (A) thru | or (H) of the locking mechanism of FIG. FIG. 2 is a schematic cross-sectional view (A) of a stimulable phosphor sheet accommodated in the radiographic imaging cassette of FIG. 1 and an enlarged cross-sectional view (B) near the surface of a sheet-like image recording unit. 2A is a cross-sectional view showing a modified example of the cassette of FIG. 2, a cross-sectional view showing a deformed state by applying an external force to the front member, a cross-sectional view showing a deformed state by applying an external force to the back member, FIG. FIG. 6D schematically shows the state of deformation of the double-sided tape as the joining means in FIG. 6C and FIG. 6C schematically shows the state of deformation of the elastic adhesive as the joining means in FIG. E). It is a side view which shows schematic structure of the radiographic image reading apparatus which can read a radiographic image from the cassette 1 for radiographic imaging of FIG. FIG. 8 is a schematic plan view of the radiation image reading apparatus of FIG. 7. It is a principal part side view for demonstrating the separation operation | movement of the cassette of the radiographic image reading apparatus of FIG. It is sectional drawing (A) which shows another modification of the cassette of FIG. 2, and sectional drawing (B) which shows the state which applied and applied the external force to the back member.

DESCRIPTION OF SYMBOLS 1 Radiographic imaging cassette, Cassette 2 Apparatus main body 10 Front member 20 Back member 20a Magnet 20b Base 20c Joint part 20d Double-sided tape 20e Elastic adhesive 20f Iron foil 20g Magnet 20h Rib 28 Storage phosphor sheet (sheet-like recording medium)
28a Storage phosphor layer 29 Buffer material 39 Push latch part (push latch mechanism)

Claims (5)

Containing a sheet-like recording medium composed of a front member and a back member, formed by a vapor phase growth method and made of columnar crystals having a thickness in the range of 20 μm to 2 mm,
The front member and the back member are configured to be relatively detachable in substantially the same direction as the growth direction of the columnar crystals,
A cassette in which a non-contact buffer member is always disposed between the front member and the recording medium. The sheet-like recording medium has a sheet-like image recording unit that is crystal-grown on one side of a rectangular sheet by the vapor phase growth method in a direction substantially perpendicular to the sheet surface, and is opposite to the sheet-like image recording unit Integrated with the back member side at the surface,
The cassette according to claim 1, wherein the front member is configured to be removable from the back member and the sheet-like recording medium. The cassette according to claim 1 or 2, wherein the back member and the sheet-like recording medium are joined so as to be relatively movable. The cassette according to claim 1, 2 or 3, wherein a gap between the recording medium and the front member is in a range of 0.5 to 2 mm, and the buffer member is thinner than the gap. The cassette according to claim 1, wherein the buffer member is made of a nonwoven fabric.

Images