PATENT ABSTRACT
An embodiment of the present invention may include a cassette for accommodating a stimulable phosphor sheet, comprising a back base with a plurality of adhesive parts which protrude from an inner surface of the back base; a support plate on which the stimulable phosphor sheet is attached, the support plate being adhered exchangably onto the adhesive parts; and a front cover placed so as to cover the inner surface of the back base and to form the cassette.

PATENT DESCRIPTION
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application is a divisional application of U.S. application Ser. No. 10/638,780 filed Aug. 11, 2003. Priority under 35 U.S.C. §119(a) and 35 U.S.C. §365(b) is claimed from Japanese Application No. 2002-237700 filed 16 Aug. 2002, the disclosure of which is also incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to a radiographic image reading apparatus for reading radiographic image information stored in a storage phosphor sheet.  
         [0004]     2. Description of Related Art  
         [0005]     A radiographic image reading apparatus outputting image information as digital data has been frequently used for digitizing radiographic image information generated at hospitals to store and to telephotograph the digitized radiographic image information. As a radiographic image reading apparatus for outputting such digital data, a radiographic image reading apparatus using a storage phosphor sheet is well known.  
         [0006]     In a radiographic image reading apparatus for reading the radiographic image information from the storage phosphor sheet as described above, a mechanism for taking out the storage phosphor sheet from the cassette and for conveying only the storage phosphor sheet in the apparatus, is ordinarily used. In such a conveyance mechanism, a one side reference conveying system in which the storage phosphor sheet is conveyed by shifting it to one side along the conveying direction thereof, is generally used. However, in a system in which the cassette is conveyed in the apparatus like the present invention, a conveying method in which the weight of the cassette is considered, is required. Further, because the weight difference between a small cassette having 18×24 cm size and a large cassette having 14″×17″ size is large, a technique that the both cassettes are stably conveyed and the image information is accurately read is required. On the other hand, in an operation in which the cassette is inserted into the apparatus, it is required that the information attached to the cassettes having various sizes is inexpensively and securely read. Further, a simple inserting method is required. As described above, in a system in which the cassette is conveyed in the apparatus, there are various problems to be solved as compared with a case in which only the storage phosphor sheet is conveyed in an apparatus.  
       SUMMARY OF THE INVENTION  
       [0007]     The present invention was made in consideration of such a situation. Thus, the present invention may provide a radiographic image reading apparatus which can stably read cassette code information without a sensor which can read the information in a wide area, and which can steadily read image information stored in a phosphor sheet.  
         [0008]     In accordance with a first aspect of the invention, a radiographic image reading apparatus for reading image information stored in a storage phosphor sheet from a cassette in which the storage phosphor sheet is incorporated and on which code information is recorded at a predetermined position, comprises:  
         [0009]     an insertion opening into which the cassette is inserted along to an end side of a width direction of the insertion opening;  
         [0010]     a code information read mechanism for reading the code information of the inserted cassette positioned along the end side of the width direction of the insertion opening;  
         [0011]     a width shifting mechanism for shifting the cassette in which the code information is read by the code information read mechanism, to a center of a width direction of a conveyance mechanism for conveying the cassette;  
         [0012]     a separation mechanism for separating a front panel of the cassette from a back panel of the cassette in which the storage phosphor sheet is incorporated, after the cassette is shifted by the width shifting mechanism in order to read the image information stored in the storage phosphor sheet; and  
         [0013]     an image information read mechanism for reading the image information stored in the storage phosphor sheet of the back panel separated by the separation mechanism so as to read the image information.  
         [0014]     Because the code information of the cassette inserted into the insertion opening along to one end side of the width direction of the insertion opening is read, the code information which is positioned within a predetermined range can be read, and thereby the code information of the cassette can be stably read even if no expensive read sensor which can read the information in a wide area is provided. Furthermore, because a cassette in which the code information is read is shifted to the center of a width direction of the conveyance mechanism and the front panel of the shifted cassette is separated from the back panel, the front panel can be stably separated from the back panel by a simple mechanism.  
         [0015]     The code information of the cassette may include information for specifying a size of the cassette, and  
         [0016]     the width shifting mechanism may shift the cassette on the basis of the code information.  
         [0017]     The code information including the information for specifying the size of the cassette is stably read, and the cassette is shifted by using the code information. Consequently, the cassette can be shifted easily and correctly.  
         [0018]     The image information read mechanism may read the image information while the storage phosphor sheet is sub-scanned on a center reference.  
         [0019]     The sub-scanning which requires precise conveyance, can be easily balanced. When the image is read, the nonuniformity of speeds can be suppressed to increase reliability and stability. Moreover, the collecting balance of a collecting system for reading the image can be also adjusted by a center reference, and the image quality of the central part of a screen, at which the image quality is required, can be aligned against any size of a cassette.  
         [0020]     The radiographic image reading apparatus may further comprise:  
         [0021]     a carrying mechanism for carrying the cassette in which the code information is read by the code information read mechanism, from the insertion opening to an inside of the apparatus; and  
         [0022]     an insertion shutter for closing the insertion opening after the cassette is carried in the inside of the apparatus from the insertion opening by the carrying mechanism;  
         [0023]     wherein the width shifting mechanism shifts the cassette after the insertion opening is closed by the insertion shutter.  
         [0024]     Because the cassette is shifted after the insertion opening is closed, an operator does not have bad feeling caused by the movement of a cassette in the state in which a hand of the operator is touched to the cassette.  
         [0025]     The radiographic image reading apparatus may further comprise:  
         [0026]     an erase mechanism for easing image information remaining in the storage phosphor sheet after the image information of the storage phosphor sheet is read by the image information read mechanism;  
         [0027]     a uniting mechanism for uniting the back panel with the front panel after the image information remained in the storage phosphor sheet on the back panel is erased by the erase mechanism; and  
         [0028]     an ejection mechanism for conveying the cassette with the storage phosphor sheet is united by the uniting mechanism, on a center reference to eject the cassette.  
         [0029]     Because the cassette is ejected by the center reference, the ejection control of the cassette can be easily executed.  
         [0030]     The image information may be read from a plurality of cassettes having different sizes from each other.  
         [0031]     The radiographic image reading apparatus may further comprise:  
         [0032]     at least two modes of a read mode for reading the image information stored in the storage phosphor sheet with the image information read mechanism, and an erase mode for erasing the image information stored in the storage phosphor sheet with the erase mechanism; and  
         [0033]     a switching mechanism for switching the two modes.  
         [0034]     Because the radiographic image reading apparatus is configured to include at least two modes of the read mode and the erase mode, and to includes the switching mechanism for switching the at least two modes in a radiographic image reading apparatus body, a user can select a necessary mode for a short time. Then, the work efficiency is improved.  
         [0035]     The read mode may perform at least two operations of a read operation for reading the image information from the storage phosphor sheet with the image information read mechanism, and an erase operation for erasing image information remaining in the storage phosphor sheet after the read operation is carried by the erase mechanism.  
         [0036]     Because the read mode is configured to perform at least two operations of the read operation and the erase operation, there in no necessity to perform the erase mode after the read mode. Then, the work efficiency of a user is improved.  
         [0037]     The erase mode may perform the erase operation without performing the read operation for reading the image information with the image information read mechanism.  
         [0038]     Because the erase mode is configured to perform the erase operation without performing the read operation, the radiographic image which has been erroneously photographed can be erased without being read. Then, the work efficiency of a user is improved.  
         [0039]     The read mode may be automatically selected at starting of the radiographic image reading apparatus, and the erase mode and the read mode are alternately selected by operating the switching mechanism.  
         [0040]     Because the read mode which is used most frequently at the starting, is automatically selected, a user can ordinarily use the apparatus without being conscious of the erase mode. Moreover, because the switching mechanism for being able to switch the erase mode and the read mode alternately is provided, the two modes can be selected with a simple operation. Then, the work efficiency of the user is improved.  
         [0041]     In a case that the erase mode is selected, when the cassette is supplied to the radiographic image reading apparatus within a predetermined time, the erase operation may be executed; and when the cassette is not supplied to the radiographic image reading apparatus within the predetermined time, the erase mode may be automatically finished and the radiographic image reading apparatus may return to the read mode.  
         [0042]     The radiographic image reading apparatus is configured so that, in case of the selection of the erase mode, when a cassette is supplied to the apparatus within a predetermined time, the erase operation is executed, and that, when the cassette is not supplied to the apparatus within the predetermined time, the erase mode is automatically finished and the apparatus returns to the read mode. Consequently, the danger of the erroneous erase of the storage phosphor sheet in which a user wants to read the image, is eliminated.  
         [0043]     In the erase mode, when the cassette is supplied to the radiographic image reading apparatus within a predetermined time after the erase operation is finished, the erase mode may be continuously carried out, and when the cassette is not supplied to the radiographic image reading apparatus within the predetermined time, the erase mode may be automatically finished and the radiographic image reading apparatus may return to the read mode.  
         [0044]     The radiographic image reading apparatus is configured so that, in the erase mode, when a cassette is supplied to the apparatus within a predetermined time after the erase operation is finished, the erase operation is continuously executed, and that, when the cassette is not supplied to the apparatus within a predetermined time, the erase mode is automatically finished and the apparatus returns to the read mode. Consequently, the trouble of re-switching to the erase mode at every chance of erasing the image is saved in such a case where a user wants to erase a plurality of sheets continuously, and then the work efficiency of the user is improved. Moreover, because the apparatus automatically return to the read mode after the erase work is finished, the danger of the erroneous erase of the storage phosphor sheet in which the user wants to read the image, is eliminated.  
         [0045]     The radiographic image reading apparatus may further comprise a display for displaying the predetermined time.  
         [0046]     Because the display for displaying a predetermined time is provided, a waiting time for continuously easing the image can be confirmed. Consequently, a user can perform erase work without anxiety.  
         [0047]     A residual time of the predetermined time displayed on the display is displayed by count down.  
         [0048]     Because the predetermined residual time is displayed by count down, the necessity of caring about the residual time is eliminated, and a user can perform erase work without anxiety.  
         [0049]     The erase mode may include a plurality of erase operations in which erase speeds are different from each other, and the plurality of erase operations may be selected by operating the switching mechanism.  
         [0050]     Because the radiographic image reading apparatus is configure so that the erase mode includes a plurality of erase operations in which erase speeds are different from each other, and that the plurality of erase operations can be switched by the switching mechanism for switching the read mode and the erase mode, a user can select a desired erase speed with a few operations easily. Then, the work efficiency of the user is improved.  
         [0051]     An operation of switching from the read mode to the erase mode may require a long pressing operation of a button or a switch of the switching mechanism.  
         [0052]     Because the radiographic image reading apparatus is configure so that the operation for switching the read mode to the erase mode requires to perform a long pressing operation of a button or a switch, the accident of loosing image information by entering the erase mode erroneously during the reading of the image can be prevented.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0053]     Embodiments will now be described, by way of example only, with reference to the accompanying drawings which are meant to be exemplary, not limiting, and wherein like elements are numbered alike in several Figures, in which:  
         [0054]      FIGS. 1A and 1B  are perspective views showing a cassette when the front panel and the back panel are separated;  
         [0055]      FIG. 2  is a sectional view showing the cassette when the front panel and the back panel are united;  
         [0056]      FIGS. 3A, 3B ,  3 C,  3 D,  3 E,  3 F,  3 G and  3 H are views showing the back panel and the front panel when they are in a locked state;  
         [0057]      FIGS. 4A and 4B  are views showing a lock mechanism of the back panel and the front panel;  
         [0058]      FIGS. 5A and 5B  are views showing the back panel of the cassette when the back panel is looked at from the back side thereof;  
         [0059]      FIG. 6  is a view showing a configuration example of a radiographic image reading apparatus;  
         [0060]      FIG. 7  is a view showing a relation between a conveyance mechanism and a sub-scanning mechanism;  
         [0061]      FIG. 8  is a view showing a cassette insertion and ejection section when the section is looked at from above;  
         [0062]      FIG. 9  is a view showing a display and operation section when it is looked at from the front;  
         [0063]      FIGS. 10A and 10B  are vies showing a relation between the conveyance mechanism and the sub-scanning mechanism at the delivery of the back panel;  
         [0064]      FIG. 11  is a view showing a positional relation of the cassette in case of an upper side reference and a center reference; and  
         [0065]      FIG. 12  is a transition diagram showing changes of the display contents of a display. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0066]     Hereinafter, the attached drawings are referred while the preferred embodiments of the present invention are described in detail.  FIGS. 1A  to  5 B are views showing a cassette  1  to be used in a radiographic image reading apparatus of the present invention.  
         [0067]     The cassette  1  is composed of a front panel  10  and a back panel  20  which can be separated from each other.  FIGS. 1A and 1B  are perspective views showing the cassette  1  when the front panel  10  and the back panel  20  are separated.  FIG. 2  is a sectional view showing the cassette  1  when the front panel  10  and the back panel  20  are united.  FIGS. 3A, 3B ,  3 C,  3 D,  3 E,  3 F,  3 G and  3 H are sectional views of the cassette  1  which show the states of the lock mechanism.  FIGS. 4A  and  4 B are views showing the lock mechanism of the cassette  1 .  FIGS. 5A and 5B  are views showing the back panel  20  when it is looked at from the back side thereof (opposite side of the front panel  10 ).  
         [0068]     The front panel  10  is composed of a frame  11  and a front face plate  13 . A non-woven fabric  17  is stuck on the inner face of the front face plate  13 . The frame  11  is composed of a frame side face  110 , a frame bottom face  111 , an inclined face  112  and an inward face  113  forming a predetermined angle inclination, a frame inner surface  114 , a shielding projection  115 , an insertion opening  14 , notches  15   a  and  15   b , and locking recesses  16   a ,  16   b ,  16   c  and  16   d . The inclined face  112  and the shielding projection  115  form a recess  12  in the inner part of the frame  11 .  
         [0069]     By the formation of the inclined face  112  on the frame  11  in such a way, the alignment accuracy when the back panel  20  is united with the front panel  10  can be designed roughly. That is, by the formation of the inclined face  112  on the frame  11 , the inclined face  112  automatically guides the back panel  20  to the uniting position even when the position at which the back panel  20  is united with the front panel  10  is shifted a little. Consequently, the requirements for parts accuracy and assembly accuracy on an apparatus side can be relaxed. Moreover, when fine deformations are produced in the framework and the mechanism of an apparatus at the transportation of the apparatus, the probability of causing a defect can be reduced very much by the uniting work of the front panel  10  and the back panel  20 .  
         [0070]     It is preferable that the frame  11  is made of a material bearable with large weight at full weighting photographing such as aluminum, rigid plastic or the like. It is preferable that the front face plate  13  is made of a member which has large strength and a relatively small radiation absorption rate such as aluminum, carbon fiber reinforced plastic or the like.  
         [0071]     Because a cassette of the type of opening and closing the side face side of the cassette or the type of drawing out a side face plate of the cassette cannot be configured to have the structure having no rift of the outer periphery of the side face of the cassette, the structure is weak at a load from the front side. On the contrary, because the present embodiment has the structure in which the frame  11  of the front panel  10  covers the outer periphery of the front face plate  13  without any rift, the embodiment can receive the load imposed from the front panel  10  side of the cassette  1  during photographing on the whole frame  11  equally. Consequently, the structure of the embodiment has the strong durability to the load imposed from the front panel  10  side.  
         [0072]     The back panel  20  is formed by means of a back panel body  21 , a radiation absorbing sheet  25 , a support plate  27  and a storage phosphor sheet  28 .  
         [0073]     The storage phosphor sheet  28  is bonded to the support plate  27  with the radiation absorbing sheet  25  between them. The radiation absorbing sheet  25  is, for example, a lead sheet, and absorbs a radiation transmitted through the storage phosphor sheet  28 . Thereby, it is prevented that a back-scatter transmitted from the compositions, such as the support plate  27  and the back panel body  21 , of the cassette  1 , which are positioned behind the storage phosphor sheet  28 , and a back-scatter transmitted from the other compositions which would exist behind the cassette  1  reach the storage phosphor sheet  28 . The support plate  27  is bonded on the surface of bonded parts  214  with a double-faced adhesive tape or a bonding agent at the strength capable of being reference-bonded. The bonded parts  214  and ribs  215  form air phases  23  to contribute to the weight saving of the cassette. As described above, the storage phosphor sheet  28  having the support plate  27  form an integral structure with the back panel body  21  in the form capable of being peeled from each other.  
         [0074]     When the storage phosphor sheet  28  is wanted to be exchanged, the storage phosphor sheet  28  is peeled off from the bonded parts  214  together with the support plate  27 . After that, a support plate  27  to which a new storage phosphor sheet  28  is attached may be bonded to the bonded parts  214  with double-faced adhesive tapes, a bonding agent or the like. When the double-faced adhesive tapes are used for the boding of the support plate  27  to the bonded parts  214 , it is preferable that the double-faced adhesive tapes are previously bonded on the bonding parts of the support substance  27  with the bonded parts  214 . In the case where the double-faced adhesive taps are previously bonded on the support substance  27  side, the double-faced adhesive tapes do not remain on the bonded parts  214  side of the back panel  21  when the support plate  27  is peeled off from the back panel  21 , and the double-faced adhesive tapes are peeled off together with the support plate  27  of the storage phosphor sheet  28 . Consequently, the cleaning processing of the bonded surfaces of the bonded parts  214  (the processing of cleaning the residuals of the previous double-faced adhesive tapes) becomes easy when the next storage phosphor sheet  28  is stuck.  
         [0075]     Moreover, the back panel  20  may be configured to attract the support plate  27  by means of magnetic force without bonding the support plate  27  to the bonded parts  214  by means of the double-faced adhesive tapes, the bonding agent or the like for making the exchange of the storage phosphor sheet  28  easy. For example, magnets are bonded on parts (bonded surfaces to the bonded parts  214 ) of the back surface (the surface on which the storage phosphor sheet  28  is not stuck) of the support plate  27 . On the other hand, the bonded parts  214  or the surfaces of the bonded parts  214  are made of a magnetic substance material. When such a configuration is adopted, it is possible to take off support plate  27  to which the storage phosphor sheet  28  is bonded from the back panel  20  easily. Moreover, it is needless to say that the similar effects can be obtained also by arranging a magnetic substance to parts of the back surface of the support plate  27  (bonded surfaces to the bonded parts  214 ) and by forming the bonded parts  214  or the surface parts of the bonded parts  214  by the use of magnets.  
         [0076]     As the support plate  27 , a light resin plate in thickness of about 0.7 mm to 1.2 mm which is uneasily deformed by changes of temperature and humidity and has a good planarity, such as a glass epoxy resin plate, a paper phenol resin plate and the like can be used. Moreover, as the support plate  27 , a light metal plate made of aluminum or magnesium alloy may be used.  
         [0077]     When a metal is used for the support plate  27 , it is desirable to form small holes on the whole surfaces of the metal plate for weight saving.  
         [0078]     The back panel body  21  is composed of a back panel back surface  210 , a back panel side face  211 , a rim  212 , the ribs  215  and a magnetic substance sheet  29 , such as iron foil. On the inside of the rim  212 , a recess  22  is formed for receiving the shielding projection  115 .  
         [0079]     When the back panel  20  and the front panel  10  are united as shown in  FIG. 2 , the recess  22  of the back panel  20 , and the shielding projection  115  and the rim  212  of the front panel  10  operate so that the shielding projection  115  enters into the recess  22  and rim  212  enters into the recess  12 . By such a method, light shielding is performed lest outside light should arrive at the storage phosphor sheet  28 . In the case where, for example, velvet, a sponge or the like is stuck in the recess  12  of the front panel  10 , the light shielding performance can be further improved.  
         [0080]     Moreover, as shown in  FIG. 2 , the front panel  10  and the back panel  20  are designed so that a gap having a certain degree of an interval is formed between the tip of the inclined face  112  of the front panel  10  and the inward face  113  of the frame  11 , and the back panel side face  211  in the state in which the front panel  10  and the back panel  20  are united. This gap is one necessary for performing the uniting of the front panel  10  and the back panel  20  smoothly. As long as the interval of the gap is within a range of about 0.2 mm to 2 mm, the uniting of the front panel  10  and the back panel  20  can be performed sufficiently smoothly. Moreover, the gap is important for absorbing the manufacturing errors of the front panel  10  and the back panel  20  and for absorbing the thermal expansion of the back panel  20 . Consequently, the gap improves the reliability and the stability of the uniting operation of the front panel  10  and the back panel  20 .  
         [0081]     Because this embodiment adopts the light shielding method based on the combination the recess and the projections as described above, there is no possibility that the outside light which has entered though the gap arrives at the storage phosphor sheet  28  to fog the storage phosphor.  
         [0082]     The back panel body  21  is, as shown in  FIG. 2 , configured to form the back panel body  21  with an ordinary plastic and to stick the magnetic substance sheet  29  such as the iron foil to the back panel back surface  210  so as to be able to be attracted to a magnet  58  shown in  FIG. 6  by magnetic force. The surface of the magnetic substance sheet  29  is in the state of being covered by a not shown laminate plastic, or in the state of being coated by paint, and is thereby configured so that the magnetic substance sheet  29  is not exposed. For example, without sticking the magnetic substance sheet  29 , the back panel body  21  itself may be formed by means of a magnetic substance plastic or the like. Moreover, the method to coat a magnetic substance material on the back panel back surface  210  or the like may be used.  
         [0083]     Moreover, the back panel back surface  210  is designed so that the back panel back surface  210  follows the plane formed by the magnet  58  when the back panel back surface  210  is attracted by the magnet  58 . That is, the back panel  20  has rigidity to a certain degree and flexibility to the degree of making it possible to follow the plane formed by the magnet  58 . By giving the flexibility to some degree to the back panel  20  as described above, even when the back panel  20  is deformed or warped by, for example, a secular change or a busy condition, the deformation or the warp of the back panel  20  is absorbed by following the plane on the magnet  58  side. Consequently, the surface of the storage phosphor sheet  28  can be always held as a plane at the reading of image information.  
         [0084]     When the photographing at which a load is imposed on the front panel  10  side (bed photographing, full load photographing or the like) is performed, the front face plate  13  of the front panel  10  produces a great deal of warp to the back panel  20  side. When the rigidity of the back panel  20  is too high in this case, the back panel  20  keeps its planarity. Consequently the storage phosphor sheet  28  is pressed from both of the front panel  10  and the back panel  20  in a great deal, and thereby the storage phosphor is damaged. As described above, when the back panel  20  has both of a certain degree of the rigidity and a certain degree of the flexibility, the back panel  20  can bend to some extent to the direction to escape from the pressing of the front panel  10 . Consequently, there is no chance of damaging the storage phosphor.  
         [0085]     Of course, the back panel  20  should not have the flexibility to the extent more than that being necessary. When the back panel  20  has the flexibility to the extent more than that being necessary, the durability of the cassette  1  decreases. Moreover, when the back panel  20  has the flexibility to the extent more than that being necessary, the quantity of the looseness of the back panel  20  owing to the self weight of the back panel  20  becomes large to produce a problem in its light shielding performance, and to produce a problem in the planarity of the storage phosphor surface at photographing.  
         [0086]     Moreover, the ribs  215  are formed on the back panel  21  with the object of completing to be light and of increasing its flexural strength, and with the object of braking the deformation quantity when the storage phosphor sheet  28  is pressed from the front panel  10  side. Moreover, lest the front face plate  13  should be contacted with the storage phosphor sheet  28  to damage the surface of the storage phosphor sheet  28  when the font face plate  13  is pressed from the front panel  10  side, the non-woven fabric  17  is arranged on the surface on the storage phosphor sheet  28  side of the front face plate  13 . The non-woven fabric  17  is preferably in a size smaller than the front face plate  13  and larger than the phosphor coating surface of the storage phosphor sheet  28  (the size capable of covering the whole phosphor coating surface). When the non-woven fabric  17  is smaller than the phosphor coating surface, such a case is not preferable because the difference of X-ray absorption in the non-woven fabric  17  is recorded in the storage phosphor sheet  28  as image information. Moreover, when the non-woven fabric  17  has a weave texture, the X-ray absorption difference owing to the weave texture is recorded on the storage phosphor sheet  28  as image information. Accordingly, it is preferable to use a non-woven fabric having a weave texture as little as possible. Moreover, in the case where the non-woven fabric becomes nappy and fibers of the non-woven fabric float in an apparatus inner part to attach to a laser optical system, the laser strength at reading becomes uniform to cause an image to generate image defects such as vertical lines on the image. It is preferable to use the non-woven fabric  17  to be nappy as little as possible. Moreover, it is preferable to use a non-woven fabric which has received fuzz preventive processing such as the permeation of resin or the like into the non-woven fabric  17  and the performance of the surface treatment processing of the non-woven fabric  17 .  
         [0087]     Although the front panel  10  and the back panel  20  can be separated, ordinarily photographing using radiations is performed in the state in which the front panel  10  and the back panel  20  are uniting as shown in  FIG. 2 .  
         [0088]     Next, by means of  FIGS. 3A  to  3 H and  FIGS. 4A and 4B , a lock mechanism of a cassette will be described.  
         [0089]     A lock mechanism is prepared in the cassette  1  for keeping the front panel  10  and the back panel  20  in their uniting state. Reference numerals  30   a ,  30   b ,  30   c  and  30   d  designate lock claws of the back panel  20 . The lock mechanism is configured so that the tip of each lock claw moves to the arrow Q 1  direction or the arrow Q 2  direction from opening parts  31   a ,  31   b ,  31   c  and  31   d  with lock ON/OFF operations.  
         [0090]     Reference numerals  32   a  and  32   b  of the back panel  20  designate lock claws different from the lock claws  30   a ,  30   b ,  30   c  and  30   d . The lock claws  32   a  and  32   b  are configured to slide into the arrow Q 1  direction or arrow Q 2  direction in opening parts  33   a  and  33   b  with lock ON/OFF operations.  
         [0091]     The lock ON state indicates the state in which the tips of the lock claws  30   a ,  30   b ,  30   c  and  30   d  protrude to the outside of the back panel side face  211 . At this time, the tip of each of the lock claws  30   a ,  30   b ,  30   c  and  30   d  is in the state of rushing into the locking recesses  16   a ,  16   b ,  16   c  and  16   d  of the front panel  10 , respectively.  
         [0092]     Sectional views of the cassette  1  on dotted lines U 1  and U 2  in  FIG. 4A  in time of the lock ON state are shown as  FIGS. 3A and 3B , respectively.  
         [0093]     In the lock ON state, the tips of the lock claws  32   a  and  32   b  are in the state in which they have moved into the arrow Q 1  direction. In this time, the phases of the notches  15   a  and  15   b  (openings formed in the frame inward face  113  and the inclined face  112 ) of the front panel  10  and the phases of the lock claws  32   a  and  32   b  are in the state of not coinciding with each other. That is, the back panel  20  is in the state of being impossible to be separated from the front panel  10 . Sectional views of the cassette  1  on dotted lines U 3  and U 4  in  FIGS. 4A and 4B  at this time are shown as  FIGS. 3E and 3F , respectively.  
         [0094]     The lock OFF state indicates the state in which the tips of the lock claws  30   a ,  30   b ,  30   c  and  30   d  enter into the inside of the back panel side face  211 . Sectional views of the cassette  1  on dotted lines U 1  and U 2  in  FIG. 4A  at this time are shown in  FIGS. 3C and 3D , respectively. Because the phases of the lock claws  32   a  and  32   b  and the phases of the notches  15   a  and  15   b  are in the state of coinciding with each other at this time, the back panel  20  can be separated from the front panel  10 . Sectional views of the cassette  1  on dotted lines U 3  and U 4  in  FIGS. 4A and 4B  at this time are shown in  FIGS. 3G and 3H , respectively.  
         [0095]     The lock claws  30   a ,  30   b ,  32   a  and  32   b  are configured to interlock with a connecting member  35 . On the other hand, the lock claws  30   c  and  30   d  are configured to interlock with a connecting member  36 . One end of each of springs  38   a  is connected with the connecting member  35 , and the other ends of the springs  38   a  are connect with the back panel body  21 . The connecting member  35  always receives the force to urge to move in the arrow Q 1  direction from the springs  38   a . The insertion opening  14  of the front panel  10  is located in a positional relation corresponding to an insertion opening  34  of the back panel  20  at the uniting.  
         [0096]     When a bar member is pushed only one time into an arrow P direction from the insertion opening  14  (insertion opening  34 ) in time of the lock ON state, the connecting member  35  moves into the arrow Q 2  direction by a predetermined distance and stops in the state to stay in the lock OFF state shown in  FIGS. 3C and 3D .  
         [0097]     When the connecting member  35  has moved into the arrow Q 2  direction, a rack-and-pinion operation is caused by the rack forms of the tips of the connecting member  35  and the connecting member  36  and a pinion  37 , and the connecting member  36  also moves into an arrow R 2  direction by the same distance and stops. At this time, the lock claws  32   a  and  32   b  move by the same distance into the arrow Q 2  direction by interlocking with the connect member  35  and stops in the lock OFF state shown in  FIGS. 3G and 3H .  
         [0098]     That is, when the bar member is pushed only one time from the insertion opening  14  (insertion opening  34 ) into the arrow P direction in the lock ON state, the lock is shifted to the lock OFF state, and the front panel  10  and the back panel  20  become in the state capable of being separated. When the bar member is not operated next through the insertion opening  14  (insertion opening  34 ), the lock OFF state is continuously kept.  
         [0099]     In time of lock OFF state, when the bar member is pushed only one time into the arrow P direction from the insertion opening  14  (insertion opening  34 ), the connecting member  35  moves into the arrow Q 1  direction by the predetermined distance and stops in the state to shift to the lock ON state shown in  FIGS. 3A and 3B .  
         [0100]     When the connecting member  35  has moved into the arrow Q 1  direction, the above-mentioned rack-and-pinion operation is caused, and the connecting member  36  also moves into the arrow R 1  direction by the same distance and then stops. In this time, the lock claws  32   a  and  32   b  move into the arrow Q 1  direction by the same distance, and become in the lock ON state shown in  FIGS. 3E and 3F .  
         [0101]     That is, in time of the lock OFF state, when the bar member is pushed only one time from the insertion opening  14  (insertion opening  34 ) into the arrow P direction, the lock state shifts to the lock ON state, and the front panel  10  and the back panel  20  become in the state of being impossible to be separated. When the bar member is not operated next from insertion opening  14  (insertion opening  34 ), the lock ON state is continuously kept.  
         [0102]     As described above, the cassette  1  of this embodiment adopts the system (push and latch system) in which the lock ON state and the lock OFF state are switched every time when the bar member is inserted from the insertion opening  14  (insertion opening  34 ) and pushed. The push and latch system is well known as the mechanism of being used for putting in and out a core of a ball-point pen from the sleeve of the ball-point pen. The push and latch mechanism is involved in a push and latch section  39  of  FIG. 4A . One ends of the springs  38   b  are connected to the push and latch section  39 , and the other ends of the springs  38   b  are connected to the back panel body  21 . The springs  38   b  always urges the push and the latch section  39  to move into the arrow Q 1  direction.  
         [0103]     The notches  15   a  and  15   b  of the front panel  10  and the lock claws  32   a  and  32   b  are arranged at positions distant from the central position C (the position indicated by an arrow C) on the side face side of the cassette  1  by predetermined distances. By the arrangement of the notches  15   a  and  15   b  and the lock claws  32   a  and  32   b  to be shifted from the central position C on the side face side of the cassette  1  (incidentally, if any one of the pairs of the lock claw  32   a  and the notch  15   a  and of the lock claw  32   b  and the notch  15   b  is shifted from the central position C of the side face side of the cassette  1 , the other pair may be arranged on the central position C on the side face side of the cassette  1 ), the back panel  20  and the front panel  10  do not unite when their directions are not correct ones. Thereby, for example, it is possible to evade the risk of user&#39;s erroneous uniting of the back panel  20  and the front panel  10  in their directions when the user separates the cassette  1  for the cleaning of the inner part of the cassette  1 , the replacement of the storage phosphor sheet  28 , or the like, and tries to perform the uniting of the back panel  20  and the front panel  10  again after the termination of the work.  
         [0104]     The mechanism for evading the risk of erroneous uniting of the back panel  20  and the front panel  10  in their directions is called as a reversal insertion prevention mechanism.  
         [0105]     Moreover, at least one projection is formed on any one of the frame  11  of the front panel  10  (for example, on the inner surface of the frame side face  110 , or on the inclined face  112  or the like) and the outer periphery section of the back panel (for example, on the outside face of the back panel side face  211 ), and at least one recess is formed on the other one, and further the projection and the recess are arranged to coincide with each other only when the front panel  10  and the back panel  20  are opposed at the correct directions. Thereby, it is possible to construct the reversal insertion prevention mechanism easily.  
         [0106]     For example, a projection shaped in a similar form to those of the lock claws  32   a  and  32   b  is formed on the outside face of the back panel side face  211 , and a recess shaped in a similar form to those of the notches  15   a  and  15   b  is formed on the frame  11  of the front panel  10 . Then, the projection and the recess are arranged in the same positional relation as those of the lock claws  32   a  and  32   b  and the notches  15   a  and  15   b  in the lock OFF state. Thereby, the reverse insertion prevention mechanism can be constructed.  
         [0107]     Moreover, when the lock mechanism is configured only by the lock claws  30   a ,  30   b ,  30   c  and  30   d  (in the state in which the lock claws  32   a  and  32   b  are not included), the side of the back panel  20  on which no lock claws reside loosens to vertically downward owing to the own weight of the back panel  20  when the cassette  1  is held so that the front panel  10  is directed to vertically upward. In such a way, the lock mechanism using the lock claws  32   a  and  32   b  can function also as a mechanism (loosening prevention mechanism) for preventing the loosening of the back panel  20  owing to its own weight.  
         [0108]     Incidentally, the loosening prevention mechanism is not always necessary for the cassette  1  having a relatively small size in which the loosening of the back panel  20  owing to its own weight is rarely produced.  
         [0109]     Moreover, in this embodiment, the insertion opening  14  and the insertion opening  34  are exhibited as rectangle forms. However, this exhibition does not mean that the insertion opening  14  and the insertion opening  34  are limited to the rectangle forms. For example, they may be shaped to be circular forms or the like.  
         [0110]      FIGS. 5A and 5B  are views showing the back panel  20  of the cassette  1  when it is looked at from the back side thereof (from the opposite side to the front panel  10 ).  FIG. 5A  indicates the lock ON state, and  FIG. 5B  indicates the lock OFF state.  
         [0111]     A code storage element  200  is stuck on the back panel back surface  210  on the same side as that of the insertion opening  34 . A clip  201  is arranged on the back panel back surface  210  on the opposite side to the code storage element  200 .  
         [0112]     In this embodiment, the code storage element  200  is a bar code label on which an optically readable pattern is printed. The code storage element  200  (bar code label) is bonded at a position distant from a corner of a cassette  1  by a predetermined distance X independent of the size of the cassette  1 .  
         [0113]     Moreover, an element capable of reading a code written in the code storage element  200  by means of radio techniques of electromagnetic waves, microwaves and the like may be used as the code storage element  200 . When the element capable of reading a code by means of the radio techniques of electromagnetic waves, microwaves and the like, the code recorded in the code storage element  200  can be accurately read even when the positional relation between the code storage element  200  and a reading apparatus of the code storage element  200  is a little shifted. Consequently, such an element is convenient. As such an element, for example, an element called as a noncontact ID label (for example, S label) can be used.  
         [0114]     When a code written in the code storage element  200  is read by means of the radio techniques of electromagnetic waves, microwaves and the like, the code storage element  200  may be arranged at the inner part of the back panel  20  in place of the back panel back surface  210 . Because reading and writing are performed by the radio techniques, it is needless that the code storage element  200  resides on the back panel back surface  210 . In this case, when a label on which the identification number (ID number) of the storage phosphor sheet  28  or the like is stuck on the back panel back surface  210 , the ID number can be visually recognized. Consequently, it can be easily known.  
         [0115]     When both of a bar code reading system and a reading system using the radio techniques are used together, it is more convenient. In this case, it is important that the contents of the bar code label and the contents recorded in the element read by means of the radio techniques correspond to each other.  
         [0116]     In the code storage element  200 , a number indicating the identification number (ID number), the date of manufacture and the lot number of a storage phosphor sheet  28 , the version number of the storage phosphor, the size information of a cassette  1 , the sensitivity correction information (or the sensitivity information) of the storage phosphor sheet  28 , and the like is recorded as a code. When the sensitivity correction information (or the sensitivity information) of the storage phosphor sheet  28  is recorded, it is possible to read the information to correct the sensitivity of the storage phosphor. For example, by changing an voltage supplied to an photoelectric conversion element such as a photomultiplier tube and the like to change the reading sensitivity of the photoelectric conversion element, the dispersion of the sensitivity of the storage phosphor sheet  28  can be corrected to make it possible to read image information always at the fixed sensitivity. Such a sensitivity correction can be also achieved by, for example, performing the shift processing of digital data generated by performing the AD conversion of an output of a logarithmic amplifier in accordance with sensitivity information. In this case, it is needless to change the voltage to be applied to the photoelectric conversion element such as the photomultiplier tube and the like.  
         [0117]      FIG. 6  is a view showing an embodiment of a radiographic image reading apparatus of the present invention.  
         [0118]     In an apparatus body  2 , a cassette insertion opening  3 , a cassette ejection opening  4 , a maintenance door  5  and casters  6  are prepared. Moreover, the apparatus body  2  is composed of a conveyance mechanism  40 , a sub-scanning mechanism  50 , a read mechanism  60 , a cassette insertion and ejection section  70 , a display and operation mechanism  80  and a body framework section  90 . The cassette insertion and ejection section  70  is configured to be able to be removed from the apparatus body  2  easily.  
         [0119]     Moreover, the sub-scanning mechanism  50  and the conveyance mechanism  40  are constructed on the same substrate  92  as that of the body framework section  90 . By arranging a rubber vibration isolator  93  between the substrate  92  and a base plate  91 , a vibro-isolating structure for preventing the propagation of the vibrations of the cassette insertion and ejection section  70  to the sub-scanning mechanism  50  is realized.  
         [0120]     Moreover, a rubber vibration isolator  94  is arranged between the upper end of the sub-scanning mechanism  50  and a not shown apparatus frame. The rubber vibration isolator  94  is for strengthen the vibro-isolating structure to the sub-scanning mechanism  50 .  
         [0121]     By means of the vibro-isolating structure like this, it can be prevented that noises are generated in read image information owing to vibrations even when a cassette is inserted into the insertion opening  3 , or when a cassette is taken out from the ejection opening  4 , or further when the apparatus body  2  is vibrated while the image information is being read from the storage phosphor sheet  28  with the read mechanism  60 .  
         [0122]     Moreover, because the sub-scanning mechanism  50  and the conveyance mechanism  40  are constructed on the same substrate  92 , a delivery position does not move when the back panel  20  is delivered from the conveyance mechanism  40  to the sub-scanning mechanism  50  as described later. Thereby, the work of the separation and the uniting of the front panel  10  and the back panel  20  can be performed stably and accurately.  
         [0123]     Moreover, lest the mechanism on the conveyance mechanism  40  and the substrate  92  should interfere with each other when the conveyance mechanism  40  inclines, an opening part capable of making the mechanism on the conveyance mechanism  40  escape to the under surface side of the substrate  92  is formed in the substrate  92 . Moreover, the base plate  91  also includes an opening part on the basis of the same reason. As described above, by the formation of the opening parts for making the mechanism on the conveyance mechanism  40  escape in the substrate  92  and in the base plate  91 , it becomes possible to construct the apparatus body  2  having a low height.  
         [0124]     However, the formation of the opening part in the base plate  91  causes a problem of the entering of outside light into the apparatus body  2 . Accordingly, a removable light shielding plate  95  having a depression of a V letter form for covering the opening part in the base plate  91  is prepared, and is attached to the base plate  91  in the state of being projected downward as shown by a reference numeral  95   a  in  FIG. 6 . Thereby, the mechanism on the conveyance mechanism  40  is escaped to the under surface side of the base plate  91  while it can be prevented that the outside light enters into the apparatus body  2 .  
         [0125]     However, when the light shielding plate  95  is attached in the state of being projected downward as designated by the reference numeral  95   a  of  FIG. 6 , the projecting section of the light shielding plate  95  hinders when the apparatus body  2  is conveyed. Accordingly, when the apparatus body  2  is conveyed, the light shielding plate  95  is attached in the state of projecting upward as designated by a reference numeral  95   b  in  FIG. 6 . Thereby, the projection section of the light shielding plate  95  is not any hindrance when the apparatus body  2  is conveyed.  
         [0126]     As described above, an opening part is formed in the base plate  91 . The V letter formed light shielding plate  95  for shielding the opening part from light is configured to be able to be attached both in the states of being projected upward and of being projected downward. The light shielding plate  95  is attached to the base plate  91  to be projected upward at the conveyance of the apparatus body  2  and to be projected downward at an operation of the apparatus body  2 . Consequently, the rotation and the movement of the conveyance mechanism  40  are allowed while the height of the apparatus body  2  can be lowered.  
         [0127]     Next, the operations of a radiographic image reading apparatus of the present invention will be described by means of  FIG. 6  to  FIG. 12 .  
         [0128]      FIG. 7  is a view showing a relation between the conveyance mechanism  40  and the sub-scanning mechanism  50  of the radiographic image reading apparatus of the present invention.  FIG. 8  is a view showing the cassette insertion and ejection section  70  of the radiographic image reading apparatus of the present invention when it is looked at from above.  FIG. 9  is a view showing the display and operation section  80  of the radiographic image reading apparatus of the present invention when it is looked at from the front.  FIGS. 10A and 10B  are views showing a relation between the conveyance mechanism  40  and the sub-scanning mechanism  50  at the delivery of the back panel of the radiographic image reading apparatus of the present invention.  FIG. 11  is a view showing a positional relation of the cassette  1  in case of an upper side reference and a center reference of the radiographic image reading apparatus of the present invention.  FIG. 12  is a transition diagram showing changes of the display contents of a display  81  of the radiographic image reading apparatus of the present invention.  
         [0129]     Fist, a not shown circuit breaker is tuned on for initiating the apparatus. Next, when an operation switch  82  shown in  FIG. 9  is pushed (operation  1 ), a power source is supplied to a not shown control section of the apparatus body  2 . An operation lamp  84  is lighted. At the same time, display indicating while initializing on the display  81  (an LCD panel in this embodiment) as shown in  FIG. 9  or as designated by a reference numeral  811  in  FIG. 12 . At the same time, the initializing of the apparatus body  2  and of the not shown control section begin. For making the user know the lapse of time until the termination of initialization sufficiently, bar display using marks ▪ and □ as shown in  FIG. 9  or as designated by a reference numeral  811  in  FIG. 12  is performed. Count down display by replacing a mark ▪ with a mark □ one by one with the lapse of time from the state in which all marks are ▪ to the state in which all marks are □ is performed. Alternatively, the lapse of time until the termination of the initialization may be displayed by means of the numbers of seconds. When the initialization terminates, the display of the display  81  changes to “READY” display as designated by a reference numeral  812  in  FIG. 12 , and it becomes possible to insert the cassette  1  into the apparatus body  2 .  
         [0130]     The radiographic image reading apparatus of the present invention includes at least two modes as its operation mode. One of them is a reading mode for reading image information from the storage phosphor sheet  28 , the other one is an erase mode for erasing image information from the storage phosphor sheet  28 . When an apparatus is initiated, the reading mode is automatically selected. Two kinds of erase modes are prepared as a MODE  1  (high speed erasing) and a MODE  2  (low speed erasing). The MODE  1  (high speed erasing) is the erase mode which is performed before radiation photographing or after the lapse of a fixed time after the reading of the image information at the last time. The MODE  1  is the erase mode to be used, for example, at the use of the radiographic image reading apparatus after erasing all of the storage phosphor sheets  28  at every morning. On the other hand, the MODE  2  (low speed erasing) is the erase mode to be used in the case where image information is not necessary, for example, when radiation photographing was mistaken.  
         [0131]     Next, the erase modes and the transition of the contents displayed on the display  81  will be described by means of  FIG. 12 .  
         [0132]     For shifting to the erase mode, an erase switch  83  of  FIG. 9  is pushed for 3 to 5 seconds (operation  2 ). By the operation  2 , the display of the display  81  changes from “READY” display to “ERASE MODE 1/▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ QUICK” display as designated by a reference numeral  813  in  FIG. 12 . Then, the radiographic image reading apparatus has shifted to the MODE  1  (high speed erasing) of the erase mode, and begins the countdown for 10 seconds in the display similar to that at the initializing (count down display by replacing a mark ▪ with a mark □ one by one with the lapse of time from the state in which all marks are ▪ to the state in which all marks are □ is performed). When the radiographic image reading apparatus is left for 10 seconds in the state, the apparatus automatically returns to the reading mode. When the erase switch  83  is pushed before 10 seconds have passed from “ERASE MODE 1/▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪” display (operation  3 ), the display of the display  81  changes to “ERASE MODE 2/▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ SLOW” display. Then, the erase mode shifts to the MODE  2  (low speed erasing), and the countdown for 10 seconds begins. When the radiographic image reading apparatus is left for 10 seconds in the state, the apparatus automatically returns to the reading mode.  
         [0133]     When the cassette  1  is inserted into the insertion opening  3  during the countdown (within 10 seconds after a mode transition) in both of the cases where the erase mode is the MODE  1  (high speed erasing) and where the erase mode is MODE  2  (low speed erasing) (operation  5  or operation  6 ), the cassette  1  is taken into the inner part of the apparatus body  2 , and erasing is performed. When the erasing completed and the next erasing becomes possible, the display  81  again displays countdown. After that, by the insertion of the next cassette  1  into the insertion opening  3  by the termination of the countdown similarly, erasing work can be continuously performed.  
         [0134]     As described above, because the radiographic image reading apparatus is configured to perform countdown for  10  seconds when the apparatus enters into the erase mode and to perform the erasing continuously when the cassette  1  is inserted into the insertion opening  3  before the termination of the countdown, it is possible to save the trouble of reentering into the erase mode at every erasing when a user wants to erase a plurality of sheets continuously. Moreover, because the radiographic image reading apparatus is configured to return to the reading mode automatically when the cassette  1  is not inserted into the insertion opening  3  before the termination of the countdown for 10 seconds, the risk of erroneously erasing the storage phosphor sheet  28  which is wanted to be read after the termination of erasing work is removed.  
         [0135]     When a user wants to terminate the work of the radiographic image reading apparatus (wants to turn off the power), the user push the operation switch  82  for 5 seconds (operation  7 ). By the operation, the display  81  displays “5 seconds until power OFF”, and the display section of the number of seconds changes to 5, 4, 3, 2 and 1 sequentially. After the lapse of 5 seconds, “ready to power OFF” display appears. At the appearance of the display, countdown begins. When the preparation of the power OFF has been completed, the display  81  enters in its light-out state, and the power source which has been supplied to the control section of the apparatus body  2  is cut off.  
         [0136]     When an error is once produce in any states or any modes, the operation of the radiation image reading apparatus stops, and the error message designated by a reference numeral  815  shown in  FIG. 12  is displayed by the display  81 . Hereupon, “XXXXX” indicates a part to which an error code is displayed, and “YYYYYYYYYY” indicates a part showing an operation which a user should do or a part where work contents are displayed. Because the display  81  of the apparatus body  2  displays an operation which the user should do or the work contents together with an error code, the user can instantaneously perform the return from the error.  
         [0137]     Next,  FIG. 6  is used while the reading operation in the reading mode of the radiographic image reading apparatus is described. Incidentally, the erasing operation in the erase mode is similar to the contents which will be described in the following as to the insertion operation and the ejection operation of the cassette  1  and the movement of the cassette  1  in the inner part of the apparatus.  
         [0138]     As shown in  FIG. 6 , a cassette  1  to which radiation image photographing has been performed is inserted into the insertion opening  3  along an arrow Al direction. At this time, the insertion is performed so that the insertion opening  14  is located on the lower side and the front face plate  13  of the front panel  10  faces to the obliquely lower side. That is, the insertion is performed so that the reading surface of the storage phosphor sheet  28  faces to the obliquely lower side. Moreover, the cassette  1  is inserted along the wall on the left side of the insertion opening  3  to be flush against the left in this embodiment.  
         [0139]     A cassette detection sensor  701  in which a light emission section  701   a  and a light reception section  701   b  operate as a pair is arranged in an insertion guide section  71   a  of the cassette insertion and ejection section  70 . The reference numeral  701   a  designates the light emission section for emitting infrared light, and the reference numeral  701   b  designates the light reception section for receiving the infrared light emitted from the light emission section  701   a . When the cassette  1  is inserted into the insertion opening  3 , the infrared light emitted from the light emission section  701   a  of the cassette detection sensor  701  is intercepted by the cassette  1 , and the light does not arrive at the light reception section  701   b  of the cassette detection sensor  701 . The apparatus body  2  detects the insertion of the cassette  1  by means of the interception of the infrared light as a cassette detection signal.  
         [0140]     At least two pairs of the cassette detection sensors  701  are prepared as shown in  FIG. 7 . That is, a pair of a light emission section  701   a - 1  and a light reception section  701   b - 1  is arranged on the left side of the insertion opening  3 . A pair of a light emission section  701   a - 2  and a light reception section  701   b - 2  is arranged at the center of the insertion opening  3 . Only in the case where all of the at least two pairs of the cassette detection sensors  701  output the detection signal, an insertion roller  72   a  is actuated by a not shown insertion motor. The actuating of the insertion roller  72   a  in turn conveys the cassette  1  into the arrow A 1  direction, and then the tip of the cassette  1  arrives at an insertion opening shutter  74 . By actuating the insertion roller  72   a  for a while after the tip of the cassette  1  has arrived at the insertion opening shutter  74 , it is possible to align the cassette  1  to be horizontal against the insertion opening shutter  74  even if the cassette  1  is inserted in the state of being inclined. An insertion roller  72   b  is a driven roller, and the cassette  1  is nipped by the insertion rollers  72   a  and  72   b  with the force sufficient for the conveyance.  
         [0141]     When at least one pair of the cassette detection sensor  701  of the at least two pairs of the cassette detection sensors  701  does not output the detection signal, the radiographic image reading apparatus recognizes that the cassette  1  was not inserted to be flush against the left side, and displays a warning message indicating the insertion of the cassette  1  to be flush against the left side on the display  81  (a liquid crystal panel capable of displaying letters and signs in this embodiment). As in this embodiment, by the arrangement of the pair of the cassette detection sensors  701   a - 2  and  701   b - 2  by the insertion opening  3 , even when the cassette  1  having any size is inserted from any direction, the cassette detection sensors  701   a - 2  and  701   b - 2  output a detection signal without fail. Consequently, even when the cassette  1  is not inserted in the state of being flush against the left side, the warning message indicating the insertion of the cassette  1  in the state of being flush against the left side can be displayed without fail.  
         [0142]     Moreover, because an insertion opening indicator  76  turns on and off and a warning beep sound simultaneously to the display of the warning message, the user never overlooks the occurrence of the abnormal insertion of the cassette  1 .  
         [0143]     As described above, because the abnormal insertion of the cassette  1  is informed immediately after the insertion of the cassette  1  (before a part of the cassette  1  is wholly taken into the apparatus body), the user can immediately perform a correction measure such as the reinsertion of the cassette  1 , the making of the cassette  1  to be flush against the left side, or the like without losing time.  
         [0144]     When the rotation of the not shown insertion motor, which begins at the detection of the cassette  1 , stops, a code read member  702  reads the above-mentioned various kinds of information including the size information of the cassette  1  from the code storage element  200  of the cassette  1 . In this embodiment, the code storage element  200  is the bar code label, and the code read member  702  is a bar code reader. However, the code storage element  200  and the code read member  702  are not limited to the above-mentioned ones.  
         [0145]      FIG. 8  is a view showing the cassette insertion and ejection section  70  looked at from above. This embodiment is configured as follows. That is, because the code read member  702  is arranged on the left side of the insertion opening  3 , by inserting the cassette  1  in the state of being flush against the left side of the insertion opening  3 , the position of the code storage element  200  (bar code label) faces to the code read member  702  (bar code reader), and the code storage element  200  (bar code label) enters into the range where the code read member  702  (bar code reader) can read the code storage element  200 . Because the width of the code of the code storage element  200  (the width of the bar code label) is configured to be a size smaller than the range where the code read member  702  (bar code reader) can read the code storage element  200 , even if the insertion position of the cassette  1  is shifted a little, namely if the cassette  1  is separated from the left side wall of the insertion opening  3  a little, the information of the code storage element  200  (bar code label) on the cassette  1  can be accurately read by the code read member  702  (bar code reader). Owing to the configuration described above, the user is not necessary for paying attention to the insertion of the cassette  1 , and the stress for inserting the cassette  1  can be reduced.  
         [0146]     In this embodiment, the cassette  1  is inserted into the insertion opening  3  in the state of being flush against the left side, but it is needless to say that the cassette  1  may be inserted into the insertion opening  3  in the state of being flush against the right side. In this case, the code read member  702  is arranged on the right side of the insertion opening  3 .  
         [0147]     The insertion opening indicator  76  is arranged in the cassette insertion and ejection section  70 . In the state in which the cassette  1  can be inserted into the insertion opening  3 , i.e. in the state in which no cassette  1  resides in the insertion opening  3  and the insertion opening shutter  74  is closed, the insertion opening indicator  76  lights, and the display  81  performs the display indicating the state in which the cassette  1  can be inserted, for example, the display of READY.  
         [0148]     In case of the state in which the insertion of the cassette  1  into the insertion opening  3  is prohibited, i.e. in case of the state in which the cassette  1  resides in the insertion opening  3 , or in the midst of taking the cassette  1  into the inner part of the apparatus body  2 , or in the state in which the insertion opening shutter  74  is opened immediately after the cassette  1  is taken into the inner part of the apparatus body  2 , then the insertion opening indicator  76  performs light-out, and the display  81  performs the display indicating the state in which the insertion of the cassette  1  is prohibited, for example, the display of BUSY.  
         [0149]     Moreover, in case of the abnormal insertion of the cassette  1 , or in case of the abnormal insertion of something other than the cassette  1 , the insertion opening indicator  76  turns on and off, and the display  81  displays a warning error message indicating the occurrence of the abnormal insertion, and further a warning beep is sounded. Thereby, the user is informed of the occurrence of the abnormal insertion. In such a way, in case of the detection of the abnormal insertion of the cassette  1 , the cassette  1  is not taken in the inner part of the apparatus body  2 .  
         [0150]     Hereupon, the abnormal insertion indicates the following cases.  
         [0151]     1) The case where at least one pair of sensor in the at least two pairs of the cassette detection sensors  701  did not output the detection signal (the case where the insertion of the cassette  1  in the state of being flush against the left side was not performed, or the like). In this case, the display  81  displays a warning error message indicating the insertion of the cassette  1  in the state of being flush against the left side.  
         [0152]     2) The case where the code read member  702  could not read any codes, or read an indistinguishable code. In this case, the display  81  displays a warning error message indicating the occurrence of a read error of the code storage element  200  (the bar code in this embodiment).  
         [0153]     The following cases can be considered as the case in which the code read member  702  cannot read a code, or the case where the code read member  702  reads an indistinguishable code.  
         [0154]     1) The case where the cassette  1  was inversely inserted.  
         [0155]     2) The case where the cassette  1  was inserted upside down.  
         [0156]     3) The case where a different cassette or something heterogeneous was inserted.  
         [0157]     4) The case where the code recorded in the code storage element  200  (bar code label) became dirty or was broken.  
         [0158]     5) The case where the code storage element  200  (bar code label) is not stuck, or is not located at a correct position.  
         [0159]     When the code read member  702  read a code correctly, the insertion opening shutter  74  is opened, and the not shown insertion motor actuates the insertion roller  72   a  to take the cassette  1  into the apparatus body  2  along the dotted line “a” in an arrow A 2  direction.  
         [0160]     When the cassette  1  has been taken in the inner part of the apparatus body  2 , the insertion opening shutter  74  is closed, and the insertion opening indicator  76  in  FIG. 8  is lighted (the insertion opening indicator  76  is lighted in the state in which the cassette  1  can be inserted, and puts out light in the state in which the insertion of the cassette  1  is prohibited). Then, the cassette insertion and ejection section  70  becomes the state in which the next cassette  1  can be inserted. When the next cassette  1  is inserted at this point of time (the insertion opening indicator  76  puts out light at this point of time), and when abnormal insertion of the cassette  1  does not happen, the insertion rollers  72   a  and  72   b  operate, and thereby the cassette  1  proceeds to a read position of the code storage element  200  by the code read member  702  to stop in the state being nipped by the insertion rollers  72   a  and  72   b . At this point of time, the code storage element  200  is read by the code read member  702 . When normal reading has been confirmed, the cassette  1  inserted after the first one continues to waiting at the insertion opening  3  until the apparatus body  2  enters in the state capable of receiving the second cassette  1  (until a rotation movement body  41  returns to the position of the dotted line “a” in  FIG. 6  to enter in its waiting state after the reading of the cassette  1  taken in the inner part of the apparatus body  2  first has been completed and the cassette  1  has been ejected through the ejection opening  4 ). When the apparatus body  2  enters in its state capable of receiving the second cassette  1 , the second cassette  1  is taken in the inner part of the apparatus body  2 . Because two cassettes  1  can be accepted almost continuously in such a way, the working efficiency is improved. Moreover, when an ejection switch  78  is pushed in the state in which the cassette  1  stops in the state of being nipped by the insertion rollers  72   a  and  72   b , the insertion rollers  72   a  and  72   b  reversely rotate to eject the cassette  1  to the insertion opening  3 . Consequently, the ejection function of the cassette  1  by the ejection switch  78  is useful for the case where it is found that the cassette  1  was erroneously inserted.  
         [0161]     The rotation movement body  41  of the conveyance mechanism  40  has been already waiting at the position of the dotted line “a” at the point of time when the insertion roller  72   a  starts, and the cassette  1  to be carried in through the insertion opening  3  with the insertion rollers  72   a  and  72   b  is received by an elevating platform  43  which moves up and down along the rotation movement body  41 . An elevating platform sensor  430  is arranged on the elevating platform  43 . When the elevating platform sensor  430  detects the tip of the cassette  1 , the elevating platform  43  operates at almost the same speed as the taking speed of the cassette  1 , and descends on the rotation movement body  41  together with the cassette  1 . The elevating platform  43  is controlled so that the upper end of the cassette  1  stops at the position designated by a reference letter Z in  FIGS. 10A and 11  in accordance with the cassette size information read from the code storage element  200 .  
         [0162]     When the upper end of the cassette  1  stops at the position indicated by the reference letter Z in  FIGS. 10A and 11 , width shifting members  42   a  and  42   b  operate according to the cassette size information read from the code storage element  200 . That is, the width shifting members  42   a  and  42   b  staying at sheltering positions S 1  in  FIGS. 10A and 10B  move into arrow M 1  directions, and stop at positions S 2  where the cassette  1  is held. At this time, width shift sensors  420   a  and  420   b  are turned on from their OFF states. When the width shift sensors  420   a  and  420   b  are not turned on, the display  81  displays the error information and the radiographic image reading apparatus stops its operation.  
         [0163]     When the width shifting members  42   a  and  42   b  is staying at the positions S 2  where the cassette  1  is held, the width shifting members  42   a  and  42   b  hold the cassette  1  in the form of holding only the frame  11  of the front panel  10  with projection sections  421   a  and  421   b  on a T 1  surface side shown in  FIG. 10B . In this time, because the width shifting members  42   a  and  42   b  do not hold the back panel  20 , by releasing the lock of the cassette  1 , the back panel  20  can be taken off without being interfered by the projection sections  421   a  and  421   b  of the width shifting members  42   a  and  42   b . As described above, because the width shifting members  42   a  and  42   b  are configured to hold only the front panel  10  and not to hold the back panel  20 , the width shifting mechanism and the holding mechanism of the cassette  1  can be made to be commonly used, and then the number of the parts of the apparatus can be curtailed and the control of the apparatus can be simplified.  
         [0164]      FIG. 11  is a view showing how positional relations of different cassette sizes are on the rotation movement body  41 . A reference numeral  1 A designates a 14×17 inch size cassette. A reference numeral  1 B designates a 14×14 inch size cassette. A reference numeral  1 C designates an 11×14 inch size cassette. A reference numeral  1 D designates a 10×12 inch size cassette. A reference numeral  1 E designates an 8×10 inch size cassette. A reference numeral  1 Fa designates a 24×30 cm size cassette. A reference numeral  1 Fb designates a 24×30 cm size cassette for mammography. A reference numeral  1 Ga designates an 18×24 cm size cassette. A reference numeral  1 Gb designates an 18×24 cm size cassette for mammography. A reference numeral  1 H designates a 15×30 cm size cassette for dental use. The position of the elevating platform  43  is controlled so that the upper ends of all of the cassettes are located at the position of an arrow z independent of their sizes. It is supposed that the control method for controlling the upper ends of the cassettes  1  always stop at the same place of the rotation movement body  41  as described above is called as upper side reference control.  
         [0165]     The advantages of the upper side reference control are the following two.  
         [0166]     1) Because the time during which the sub-scanning mechanism  50  conveys the back panel  20  to a read position B can be minimized independent of cassette sizes, the processing ability (throughput) of the apparatus can be improved.  
         [0167]     2) Because the upper ends of the back panels  20  can be projected from a sub-scanning movement plate  57  by the same distance U independent of cassette sizes (see  FIGS. 7, 10A ,  10 B and  11 ), the T 1  faces of the tips of the width shifting members  42   a  and  42   b  (see  FIGS. 7 and 10 B) can be made to escape to the interior side of the apparatus more than the positions of the sub-scanning movement plate  57  and the magnet  58  without being interfered by the sub-scanning movement plate  57  and the magnet  58 . Moreover, the width shifting members  42   a  and  42   b  can hold the cassette  1  in the form of holding the frame  11  of the front panel  10  of the cassette  1  with the projection sections  421   a  and  421   b  without being interfered by the sub-scanning movement plate  57  and the magnet  58 .  
         [0168]     Of course, a lower side reference control method, i.e. a control method for controlling the position of the elevating platform  43  so that the lower ends of the cassettes  1  always stop at the same place of the rotation movement body  41  may be adopted. In this case, because the elevating platform  43  can be descended to the lower end of the apparatus independent of the size of the cassette  1 , the control of the mechanism can be simplified. Incidentally, the two advantages described above cannot be obtained.  
         [0169]     A dotted line V shown in  FIGS. 10A and 11  is the center line of the sub-scanning movement plate  57 . The width shifting members  42   a  and  42   b  are controlled so that the centers of all of the cassettes  1  coincide with the center line of the sub-scanning movement plate  57 . That is, when the taking of the cassette  1  into the inner part of the apparatus body  2  is terminated, as shown in  FIGS. 10A and 10B , the width shifting members  42   a  and  42   b  move from the sheltering positions S 1  to the directions designated by the arrows M 1 , and stop at the positions S 2  where the cassette  1  is held (the cassette  1  shown in  FIG. 10A  is supposed to the one of 8×10 inch size). The cassette  1  positioned on the left side on the elevating platform  43  during the time moves to the central position on the elevating platform  43 . After this, all of a series of processing of the conveyance of the cassette  1  on the conveyance mechanism  40 , the sub-scanning of the back panel  20  by the sub-scanning mechanism  50 , and then ejection of the cassette  1  is performed at the central position. This is called as center reference control. As described above, when the cassette  1  is inserted into the insertion opening  3 , the cassette  1  is inserted in the state of being flush against to the left side (this insertion is called as one side reference control). The one side reference control is changed to the center reference control at the point of time when the cassette  1  is taken into the inner part of the apparatus body  2 .  
         [0170]     Ordinarily, when a film is conveyed, or when a storage phosphor sheet is conveyed, the one side reference control by which the film or the storage phosphor sheet is conveyed in the state of being flush to one side is performed. In this embodiment, because the conveyance mechanism  40  (rotation movement body  41 ) and the sub-scanning mechanism  50  should treat various sizes of the cassette  1  and the back panel  20 , the positions of the centers of gravity of the cassette  1  and the back panel  20  in the horizontal direction and the center of the sub-scanning movement plate  57  do not coincide with each other by the one side reference control. Consequently, there is the possibility that the balance of the sub-scanning which requires precise conveyance is lost to generate nonuniformity of speed at reading. Moreover, because the back panel  20  to which the storage phosphor sheet  28  is attached weights fairly heavily in comparison with a film or a simple substance of the storage phosphor sheet, the bad balance of the one side reference control is not preferable in points of the reliability and the stability. Consequently, in this embodiment, the center reference control is preferable.  
         [0171]     However, as to the insertion of the cassette  1 , as described above, it is preferable to perform the one side reference control. That is, by the one side reference control (the control in which the cassette  1  is inserted into the insertion opening  3  in the state of being flush against the left side or the right side), the code storage element  200  (bar code label) can be configured so that the position of the code storage element  200  faces to the code read member  702  (bar code reader) and the code storage element  200  is located in the range where the code storage element  200  can be read by the code read member  702 . When the insertion of the cassette  1  is performed by the center reference control, at the step of the insertion of the cassette  1  into the insertion opening  3 , the positions of the code storage element  200  and the code read member  702  shift to each other to increase the occasions at which the code of the code storage element  200  cannot be read. Accordingly, a certain cassette position adjusting mechanism becomes necessary before the read of the code storage element  200 , which makes the apparatus complicated to decrease the reliability.  
         [0172]     However, in the view of easiness of the user&#39;s insertion of the cassette  1 , it is preferable that no reference is set for the insertion of the cassette  1  and the cassette  1  can be inserted at an arbitrary position of the insertion opening  3 . As a mechanism for realizing this, it is considerable that a noncontact ID label (for example, S label) is used to the code storage element  200 . In this case, because the code read member  702  reads the information recorded in the code storage element  200  by the use of the radio techniques of the electromagnetic waves, the microwaves or the like, there is no problem even if the positional relation between the code read member  702  and the code storage element  200  is shifted a little.  
         [0173]     When an element requiring optical reading such as a bar code is selected as the code storage element  200 , the radiographic image read apparatus may be configured to read the information of the code storage element  200  after the cassette  1  has been aligned in the insertion opening  3  or in the inner part of the apparatus body  2  by the center reference or the one side reference.  
         [0174]     Moreover, when the back panel  20  is delivered between the conveyance mechanism  40  (rotation movement body  41 ) and the sub-scanning mechanism  50 , a T 2  surface of the elevating platform  43  and the sub-scanning movement plate  57  (or the magnet  58 ) interfere the deliverance of the back panel  20 . Accordingly, an interference evading opening  570  is formed in the sub-scanning movement plate  57  (see  FIG. 10A ) for a measure to evade this. Because the position of the interference evading opening  570  cannot be specified by the one side reference control and more complicated mechanism becomes necessary, the center reference control is preferable in this embodiment in this sense also.  
         [0175]     This embodiment adopts the center reference control. However, even when the one side reference control which evades the above-mentioned problems is performed, the essence of the present invention is not lost.  
         [0176]     The rotation movement body  41  of the conveyance mechanism  40  includes a rotation shaft  45 . The rotation movement body  41  can freely rotate to move at least in the range from the dotted line “a” to a dotted line “c” (the range of angle θ) around the rotation shaft  45  as the rotation center by being actuated by a conveyance motor unit  46 . The rotation to move the rotation movement body  41  is implemented by the operation in which the conveyance motor unit  46  actuates a pinion gear  47  and the pinion gear  47  in turn rotate to move on rugged form rack teeth  480  formed on the circular arc of a rotation support plate  48 .  
         [0177]     When the cassette  1  is taken in the inner part of the apparatus body  2  by the conveyance mechanism  40 , the conveyance motor unit  46  is actuated to rotate the pinion gear  47 . The rotation movement body  41  rotates to move from the position of the dotted line “a” in  FIG. 6  to the position of the dotted line “c” in an arrow A 3  direction around the rotation shaft  45  as the rotation center. When the rotation movement body  41  has rotated to move to the position of the dotted line “c”, the back panel back surface  210  of the cassette  1  including a magnetic substance is attracted by the magnetic force of the magnet  58 .  
         [0178]     In this time, by the mechanism (not shown) in which the front panel  10  of the cassette  1  is pressed to the magnet  58  side by the spring pressure for controlling the pressing quantity of the cassette  1  to the magnet  58 , the cassette  1  is pressed to the magnet  58  side.  
         [0179]     A lock opening and closing mechanism  44  and a lock pin  440  for turning on or off the lock mechanism of the cassette  1  are arranged on the elevating platform  43 . By the up and down movement of the lock pin  440 , the lock mechanism of the cassette  1  can be turned on or off.  
         [0180]     The sub-scanning mechanism  50  is composed of a support pole  51 , sub-scanning rails  52   a  and  52   b , sub-scanning movable sections  53   a  and  53   b , pulleys  55 , a steel band  54 , a sub-scanning movement plate fixing member  56 , the sub-scanning movement plate  57 , the magnet  58 , a balancing weight  59 , and an actuating section (not shown) composed of a sub-scanning motor and a speed reducer. The sub-scanning movement plate  57  is fixed to the sub-scanning movable sections  53   a  with the sub-scanning movement plate fixing member  56  put between them. Both of the ends of the steel band  54  are fixed to the sub-scanning movement plate fixing member  56  and the balancing weight  59 . The pulleys  55  are connected to the not shown actuating section, and the pulleys  55  transmit the power of the not shown actuating section to the steel band  54 . The sub-scanning movement plate  57  and the balancing weight  59  severally move up and down on the sub-scanning rails  52   a  and  52   b  by receiving the power of the not shown actuating section. A linear guide and a linear bearing guide which have high conveyance performance can be used as the sub-scanning rails  52   a  and  52   b . A planetary roller speed reducer, a pulley speed reducer and the like can be used as the not shown speed reducer.  
         [0181]     In this embodiment, the magnet  58  is a rubber magnet (permanent magnet) having a predetermined area. A sheet of the rubber magnet including the interference evading opening  570  as shown in  FIG. 10A  may be stuck to the whole surface of the sub-scanning movement plate  57 , or a predetermined sheets of divided rubber magnet may be stuck to the sub-scanning movement plate  57 . Moreover, the rubber magnet can take an arbitrary form. Moreover, a permanent magnet or an electromagnet may be used in place of the rubber magnet.  
         [0182]     The surface section of the magnet  58  which attracts the back panel back surface  210  has high planarity. When the magnet  58  attracts the back panel back surface  210 , the magnetic substance surface of the back panel back surface  210  is conformed to the plane of the magnet  58 . By utilizing the phenomenon, the reading surface of the storage phosphor sheet  28  is taken into consideration so as to be a plane as perfect as possible. Consequently, even when the back panel  20  is deformed or warped, the deformation or the warp is corrected at the point of time when the back panel back surface  210  is attracted by the magnet  58 , and then the read surface of the storage phosphor sheet  28  can secure its planarity.  
         [0183]     When the back panel  20  is attracted by the magnet  58 , the lock pin  440  housed in the lock opening and closing mechanism  44  attached to the elevating platform  43  ascends, and the tip of the lock pin  440  is inserted into the insertion opening  14  of the front panel  10 . By this operation, the lock of the cassette  1  being in the lock ON state is released to shift to be in the lock OFF state. That is, the back panel  20  and the front panel  10  become in the state capable of being separated. When the cassette  1  has shifted to the lock OFF state, the lock pin  440  descends to be housed in the lock opening and closing mechanism  44  again.  
         [0184]     When the lock of the cassette  1  has been released and the cassette  1  has shifted to be in the lock OFF state, the rotation movement body  41  rotates to move into an arrow A 6  direction, and stops at a sheltering position (for example, the position of a dotted line “b”). By this operation, it becomes possible to separate the back panel  20  and the front panel  10  completely.  
         [0185]      FIG. 7  is a view showing the state in which the back panel  20  and the front panel  10  are perfectly separated and the rotation movement body  41  is stopping at the sheltering position. By making the front panel  10  shelter from the back panel  20  at a sufficient angle, it becomes possible to prevent the interference of the back panel  20  with the front panel  10  when the back panel  20  performs its sub-scanning operation. A mechanism for performing a series of work for separating the back panel  20  and the front panel  10  in such a manner is given a general name of separation mechanism.  
         [0186]     A reference numeral  502  in  FIG. 6  designates a back panel attraction sensor. The back panel attraction sensor  502  is turned on when the back panel  20  is attracted by the magnet  58 , and is turned off when the back panel  20  is separated from the magnet  58 . When the back panel attraction sensor  502  outputs its OFF state in a time zone during which the back panel attraction sensor  502  should be in its ON state originally, the radiographic image reading apparatus regards the output signal as the indication of the peeling off of the back panel  20  from the magnet  58  or as the indication of the dropping of the back panel  20  from the magnet  58 . And then, the radiographic image reading apparatus judges the situation to be an error.  
         [0187]     When the back panel  20  has been perfectly separated from the front panel  10  by means of the separation mechanism, the not shown actuating section operates to convey (sub-scan) the back panel  20  into the arrow A 4  direction (upward direction). During the sub-scanning operation, the storage phosphor sheet  28  is subjected to main scanning in the perpendicular direction to the sub-scanning direction with a laser beam B emitted from a laser scanning unit  61 .  
         [0188]     When the laser beam acts on the storage phosphor sheet  28 , the photo-stimulable luminescence (image information) proportional to the radiation energy accumulated in the storage phosphor sheet  28  is released. The photo-stimulable luminescence is collected by a light collection mirror  64  and an end face of an optical guide  62  to be collected to a light collection tube  63  through the optical guide  62 . It is preferable to use a light collection tube having a structure like one disclosed in, for example, the specification of Japanese Patent Application No. 2000-103904 as the light collection tube  63 . A not shown photoelectric conversion element such as a photomultiplier or the like is arranged on an end face of the light collection tube  63 . The photoelectric conversion element converts the collected photo-stimulable luminescence to an electric signal. The photo-stimulable luminescence converted to the electric signal is processed by predetermined signal processing as image data. After that, the processed electric signal is output from the apparatus body  2  to image output apparatus such as an operation terminal, an image storage apparatus, an image display apparatus, a dry imager and the like (any of them are not shown) through not shown communication cables. The image information read mechanism composed of the laser scanning unit  61 , the optical guide  62 , the light collection tube  63 , the photoelectric conversion element and the like in such a manner is called as the read mechanism  60 . It is needless to say that the read mechanism  60  may be achieved by configurations other than the embodiment as long as the configuration can be a read mechanism for reading image information from the storage phosphor sheet  28 .  
         [0189]     Hereupon, several kinds of control pertaining to reading operation will be described by means of  FIG. 6 . A reference numeral  503  designates a read starting sensor. When the sub-scanning movement plate  57  ascends, the sensor  503  is turned on from its OFF state. By utilizing the timing, the not shown control section calculates a read start time or a laser light start time.  
         [0190]     A reference numeral  540  designates a pealing detection mechanism. By means of the pealing detection mechanism  540 , it is detected whether the storage phosphor sheet  28  and the support plate  27  which are stuck to the back panel  20  are floating or begin to peel from the back panel  20  or not. In the case where the storage phosphor sheet  28  and the support plate  27  are floating or begin to peel from the back panel  20 , it is apprehended that the storage phosphor sheet  28  and the support plate  27  interfere with the light collection mirror  64  and the end face of the optical guide  62  to destroy the light collection mirror  64  and the optical guide  62  or to damage the surface of the storage phosphor sheet  28 . Accordingly, the floating or the pealing of the storage phosphor sheet  28  and the support plate  27  are detected by the pealing detection mechanism  540 . Then, when the floating or the pealing of the storage phosphor sheet  28  and the support plate  27  are detected, the sub-scanning operation is stopped, and the sub-scanning movement plate  57  is made to descend to the uniting position with the front panel  10 .  
         [0191]     The pealing detection mechanism  540  is realized by, for example, the combination of a roller and a sensor. A peeling detection roller  541  having the length almost the same as that of the short size direction of the 14×17 inch size is held in the horizontal direction. A presser bar  542  used for fixing the axis of the peeling detection roller  541  is extended to the front surface side of the apparatus through supporting shaft  544 , and a peeling detection  543  is disposed on the rear end of the presser bar  542 . When the storage phosphor sheet  28  or the support plate  27  contacts with the peeling detection roller  541  on ascending, the presser bar  542  inclines around the supporting shaft  544  as a fulcrum. Then, the peeling detection sensor  543  detects the inclination to inform a peeling detection signal to the not shown control section.  
         [0192]     When the reading of image information from the storage phosphor sheet  28  is completed, the not shown actuating section begins to convey the back panel  20  into an arrow A 5  direction (lower direction). During the back panel  20  is being conveyed into the arrow A 5  direction, an erasing mechanism  65  emits erasing light C to erase the image information remaining in the storage phosphor sheet  28 . A halogen lamp, a high intensity fluorescent tube, an LED array and the like can be used as an erasing lamp to be used in the erasing mechanism  65 .  
         [0193]     In this embodiment, n (n&gt;1) erasing lamps are prepared. Moreover, a not shown lamp burning detection member watches whether lump burning of the erasing lamp has occurred or not. When the lamp burning detection member detects m (m&lt;n) erasing lamps among the n erasing lamps has generated the lamp burning, the erasing speed is controlled to be almost (n−m)/n of the erasing speed in time of no lamp burning resides, and the erasing is controlled to be performed at the same light quantity as that in time of no lamp burning resides. By such control, even when lamp burning occurred, it is prevented that the apparatus cannot be used, and reading work and erasing work can be continued in the state of the lamp burning.  
         [0194]     Moreover, because there is no chance of performing erasing in the state in which the erasing light quantity has decreased owing to the lamp burning, there is no risks of damaging diagnosis information by executing the next photographing in the state of insufficient erasing so that the remainder of the erasing of the previous image works as noises to the next image information.  
         [0195]     Moreover, when the lamp burning detection member detects all of the n erasing lamps has burned, the error display informing the occurrence of the lamp burning of all of the erasing lamps is displayed on the display  81 , and both of the read operation and the erasing operation are controlled not to be performed after that. By the control in such a way, the read work and the erasing work in the state in which erasing cannot be performed are prohibited, and the accident of performing radiation photographing by the use of a cassette  1  the erasing of which has not been performed is prevented.  
         [0196]     This embodiment is configured so that, when the reading mode is selected, the reading of image information is performed on an outward journey of the sub-scanning mechanism  50  (conveyance to the upper direction), and that the erasing of remaining image information is performed on a return journey of the sub-scanning mechanism  50  (conveyance to the lower direction). Consequently, this embodiment can effectively utilize the time necessary for the reciprocating motion of the sub-scanning mechanism  50  without consumes the time in vain. Thereby, the processing ability (throughput) of the radiographic image reading apparatus can be improved.  
         [0197]     Moreover, when the erase mode is selected, erasing is performed on an outward journey of the sub-scanning mechanism  50  (conveyance to the upper direction), and erasing is also performed on a return journey of the sub-scanning mechanism  50  (conveyance to the lower direction). The cycle time in the erase mode can be improved in comparison with the cycle time in the reading mode.  
         [0198]     Moreover, when the erase mode is selected, erasing may not be performed on an outward journey of the sub-scanning mechanism  50  (conveyance to the upper direction), and erasing may performed only on a return journey of the sub-scanning mechanism  50  (conveyance to the lower direction). In this case, the improvement of the cycle time in the erase mode cannot be expected, but it is possible to perform the control of the erase mode equally to the control of the reading mode, and thereby the control can be simplified.  
         [0199]     Moreover, in this embodiment, the erasing mechanism  65  is arranged at the lowest step of the read mechanism  60  in the vertical direction. Consequently, when the read work of image information by means of the read mechanism  60  is terminated, it is possible to switch the moving direction of the sub-scanning mechanism  50  to the return journey direction (the lower direction) immediately after the termination. Thereby, because erasing work can be started during the reciprocating motion of the sub-scanning mechanism  50  without any loss of time, the processing ability (throughput) of the radiographic image reading apparatus can be further improved.  
         [0200]     Moreover, because the arrangement of the erasing mechanism  65  to the lowest step of the read mechanism  60  in the vertical direction removes the chance of passing of the lower end of the back panel  20  at the read position B in the read mechanism  60 , accidents of interference of the lower end of the back panel  20  with a collecting mechanism such as the optical guide  62  or the like to make the descending of the back panel  20  impossible can be previously prevented. Consequently, the reliability and the stability of the apparatus can be improved.  
         [0201]     At the point of time when the back panel  20  has descended, the origin position of the sub-scanning direction is confirmed by means of a sub-scanning origin sensor  501 , and then the back panel  20  ascends to the position at which the back panel  20  is delivered to the magnet  58  with the origin position as the reference to stop the movement of the back panel  20 .  
         [0202]     When the back panel  20  stops at the position where the back panel  20  is delivered to the magnet  58 , the rotation movement body  41  which has been sheltering at the sheltering position again rotates to move to the position of the dotted line “c” to make the back panel  20  and the front panel  10  unite with each other. When the back panel  20  and the front panel  10  unite with each other, the lock pin  440 , which has been hosed in the lock opening and closing mechanism  44 , ascends, and the tip of the lock pin  440  is inserted into the insertion opening  14  of the front panel  10 . By the operation, the cassette  1 , which has been in the lock OFF state, is locked, and shifts to the lock ON state. That is, the back panel  20  and the front panel  10  are in the state of being impossible to be separated from each other. When the cassette  1  shifts to the lock ON state, the lock pin  440  descends to be housed in the lock opening and closing mechanism  44  again. The mechanism for performing the series of work for shifting the locked state of the cassette  1  from the lock OFF state to the lock ON state in such a manner is generally called as a uniting mechanism.  
         [0203]     When the uniting work of the back panel  20  and the front panel  10  has been completed by the uniting mechanism, the rotation movement body  41  again rotate to move to the position of the dotted line “b” into the arrow A 6  direction to stop there. Because the operation of peeling the back panel  20  (cassette  1 ) from the magnet  58  is performed together with the rotation movement, the back panel  20  (cassette  1 ) can be peeled from the magnet  58  with smaller force in comparison with the force in case of peeling the back panel  20  from the magnet  58  in a parallel movement. When the rotation movement body  41  stops at the position of the dotted line “b”, the width shifting members  42   a  and  42   b  move from the holding positions S 2  shown in  FIGS. 10A and 10B  into arrow M 2  directions, and stops at the sheltering positions S 1 . Thereby, the holding state of the front panel  10  is released, and the cassette  1  takes the state of capable of ascending on the rotation movement body  41 .  
         [0204]     When the holding state of the front panel  10  is released, the elevating platform  43  conveys the cassette  1  along the rotation movement body  41  into the direction of the ejection opening  4 , and to deliver the cassette  1  to ejection rollers  73   a ,  73   b . When the ejection rollers  73   a ,  73   b  receive the cassette  1 , the ejection roller  73   a ,  73   b  perform ejection operation of the cassette  1  until the cassette  1  has been completely ejected to the ejection opening  4 . When the cassette  1  has been completely ejected to the ejection opening  4 , the rotation movement body  41  rotation to move to the position of the dotted line “a” into the arrow A 6  direction and stops there. Then, the rotation movement body  41  there shifts to the state capable of receiving the next cassette  1 .  
         [0205]     This embodiment is provided with a stacker section in which about 2 to 5 cassettes  1  can be stacked at the ejection opening  4 . If the position of the cassette  1  immediately after the completion of the ejection to the ejection opening  4  is designated by a reference numeral  1   a  in  FIG. 6 , the cassette  1  ejected to the position  1   a  flops into an arrow A 8  direction from the upper end of the cassette  1  owing to the own weight of the cassette  1 , and finally moves to the position designated by a reference numeral  1   b . In order that the operation should be performed only by the own weight of the cassette  1 , a base plate section  71   c  of the ejection opening  4  is previously inclined from the position  1   a  side to the position  1   b  side. The base plate section  71   c  is formed of resin parts, and the surface of the base plate section  71   c  includes a rib form for decreasing the frictional resistance with the cassette  1 . Moreover, Teflon coating is formed lest the rib form should be scraped owing to the friction with the cassette  1  to decrease the sliding performance.  
         [0206]     Moreover, for conveying the cassette  1  surely from the position  1   a  side to the position  1   b  side, the radiographic image reading apparatus is configured to provide, for example, an ejection cassette conveyance mechanism for conveying the lower part of the cassette  1  into the arrow A 8  direction for moving the whole cassette  1  surely from the position  1   a  to the position  1   b . The ejection cassette conveyance mechanism can be realized by adopting a belt conveyance system, a roller conveyance system, or the like. Moreover, the mechanism in which the cassette  1  is pushed out from the position  1   a  side to the position  1   b  side by a not shown mechanism may be adopted. As long as the cassette  1  ejected from the ejection opening  4  is basically considered not to obturate the exit of the ejection rollers  73   a ,  73   b , the cassette  1  ejected from the ejection rollers  73   a ,  73   b  may take any form or any positional relation in the stacker section of the ejection opening  4 .  
         [0207]     Because the ejection opening  4  is configured to be able to stack about 2 to 5 ejection cassettes  1  (hereinafter, the cassette  1  ejected from the ejection opening  4  will be suitably called as ejection cassette  1 ), a user can insert the cassettes  1  which have been used for photographing into the insertion opening  3  in order until the ejection opening  4  is filled with the ejection cassettes  1  without withdrawing the ejection cassettes  1 . Generally a test using radiation photographing uses one to five cassettes  1 , averaging about 1.8 cassettes  1  per test. Consequently, if the ejection opening  4  is configured to be able to stack about two to five ejection cassettes  1 , it becomes rare that the user is troubled by the withdrawal of the ejection cassettes  1  during a test, and then the work can be effectively performed.  
         [0208]     When the next cassette  1  is ejected in the case where the stacker section of the ejection opening  4  is filled with the ejection cassettes  1 , defects such that the ejection cassettes  1  stacked in the ejection opening  4  already fall by being pushed out by the newly ejected cassette  1 , or such that the cassette  1  is tried to be compulsorily ejected to cause a breakdown, are generated. Accordingly, a not shown sensor or a mechanism is provided for detecting whether the stacker section of the ejection opening  4  is filled with the ejection cassettes  1  or not, and thereby whether the stacker section of the ejection opening  4  is filled with the ejection cassettes  1  or not is detected.  
         [0209]     In this embodiment, whether the stacker section is filled with the ejection cassettes  1  or not is detected by means of an ejection shutter  75  which is located at the upper part of ejection rollers  73   a  and  73   b  and is used for shielding the leaking light from a gap between the ejection rollers  73   a  and  73   b . That is, the radiographic image reading apparatus is also provided with a ejection shutter opening and closing detection mechanism (not shown) which judges that the stacker section is not filled when the ejection shutter  75  is closed after the ejection of a cassette  1 , and judges that the stacker section is filled when the ejection shutter  75  is not closed after the ejection of a cassette  1 . Then, the not shown control section detects the filled state of the stacker section on the basis of a detection signal from the ejection shutter opening and closing detection mechanisms. For performing the control, the radiographic image reading apparatus is configured not to close the ejection shutter  75  lastingly when a cassette  1  by which the stacker section is filled is ejected. As described above, because it is detected only by the opening and closing of the ejection shutter  75  whether the stacker section is filled or not, the apparatus can be constructed to be in a simple structure.  
         [0210]     It is preferable that, when the stacker section of the ejection opening  4  is filled with the ejection cassettes  1 , the defect is evaded by means of the following mechanisms.  
         [0211]     1) A mechanism for preventing the insertion of the cassette  1  into the insertion opening  3 .  
         [0212]     2) A mechanism for preventing to take in the cassette  1  into the inner part of the apparatus body  2  while allowing the insertion of the cassette  1  into the insertion opening  3 .  
         [0213]     3) A mechanism for stopping the cassette  1  before the reading of image information while allowing to take the cassette  1  inserted into the insertion opening  3  into the inner part of the apparatus body  2 .  
         [0214]     4) A mechanism for stopping the cassette  1  before the ejection to the ejection opening  4  after taking the cassette  1  inserted into the insertion opening  3  into the inner part of the apparatus body  2  to read image information of the cassette  1 .  
         [0215]     Moreover, it is preferable to inform a user of the state of the stacker section of the ejection opening  4  which is filled with the ejection cassettes  1  by means of the following mechanisms in addition to the adoption of the above-mentioned mechanisms.  
         [0216]     1) A mechanism for informing the user of the state by displaying a warning error message on the display  81 , by turning on and off an ejection indicator  77 , or by sounding a warning beep.  
         [0217]     2) A mechanism for informing the user of the state by displaying a message on the monitor of the not shown operation terminal connected to the display  80  or to the apparatus body  2 .  
         [0218]     3) A mechanism for informing the user of the state by providing a lid (not shown) to the insertion opening  3  to make it impossible to insert the cassette  1  by closing the lid.  
         [0219]     It is preferable that, when the stacker section of the ejection opening  4  becomes in the state in which the stacker section is not filled by the removal of a part of or all of the ejection cassettes  1  by the user, the processing of the cassettes  1  stopping in the inner part of the apparatus body  2  or at the insertion opening  3  is automatically resumed.  
         [0220]     Moreover, it is considerable that the following operation cannot be continued owing to the generation of any defect from one cause or another during the operation of taking the cassette  1  into the apparatus body  2 , during the conveyance operation after the taking of the cassette  1  into the apparatus body  2 , during the reading operation, during the operation of ejecting the cassette  1  from the apparatus body  2 , or the like. For example, a defect is produced in the conveyance mechanism  40  during the conveyance operation of the cassette  1  to make it impossible to continue the conveyance operation; the back panel  20  and the front panel  10  fall at the delivery of the back panel  20  to the sub-scanning mechanism  50 ; the front panel  10  and the back panel  20  cannot be separated; the front panel  10  and the back panel  20  cannot unite with each other; and the like. As described above, various defects can be produced.  
         [0221]     When such defects are produced, it is preferable to inform the user of the production of the defects by means of the similar mechanisms to that of informing the user of the filling of the stacker section of the ejection opening  4  with the ejection cassettes  1 .  
         [0222]     Moreover, when an error is produced in the state capable of ejecting the cassette  1  after the conveyance of the cassette  1  to the inner part of the apparatus body  2 , it is preferable not to eject the cassette  1  to the insertion opening  3 , but to eject the cassette  1  to the ejection opening  4 . The reason is that the user may be trying to insert the next cassette  1  into the insertion opening  3  after the cassette  1  have been conveyed to the inner part of the apparatus body  2 .  
         [0223]     Moreover, the radiographic image reading apparatus may be configured to examine whether the next cassette  1  has been inserted into the insertion opening  3  or not with a not shown cassette detection sensor, and to eject the cassette  1  into the insertion opening  3  when the cassette  1  is not detected in the insertion opening  3 .  
         [0224]     Moreover, the radiographic image reading apparatus also may be configured to change the destination of the ejection of the cassette  1  according to the progress of the processing, for example, to eject the cassette  1  to the insertion opening  3  when an error has been produced before the read of image information, to eject the cassette  1  to the ejection opening  4  when an error has been produced during or after the reading of image information, or the like. Moreover, the radiographic image reading apparatus may be configured not to eject the cassette  1 , but to stay the cassette  1  in the inner part of the apparatus and to stop the operation of the apparatus.  
         [0225]     Moreover, when an error is produced, it is preferable to display the information for specifying the cassette  1  in which the error has been produced, for example, the identification number (ID number) or the like of the storage phosphor sheet  28  which is stored in the code storage element  200  together with an error message on the display  81 , the monitor of the not shown operation terminal connected to the apparatus body  2  to make it possible that the user can distinguish the cassette  1  in which the error has been produced.  
         [0226]     In particular, when the cassette  1  in which an error has been produced is ejected to the insertion opening  3  or the ejection opening  4 , it is preferable to inform the user of the information for specifying the cassette  1  in which the error has been produced or an error message indicating the contents of the error.  
         [0227]     Moreover, in the case where the cassette  1  is not ejected but is stopped in the inner part of the apparatus and the operation of the apparatus is stopped when an error has been produced, if which position in the inner part of the apparatus the cassette  1  (the back panel  20 , the front panel  10  or the like) is staying at is diagrammatically displayed by means of a cartoon on the display  81 , the not shown operation terminal or the lie, or if an instruction message pertaining to what an operation procedure makes it possible to take out the cassette  1  (the back panel  20 , the front panel  10  or the like) which is staying at the inner part of the apparatus is displayed, then the cassette  1  (the back panel  20 , the front panel  10  or the like) staying at the inner part of the apparatus can be taken out for a short time.  
         [0228]     Moreover, when an error is produced in the state in which the cassette  1  cannot be ejected to the outside, or when the cassette  1  is controlled to be stopped in the inner part of the apparatus when an error is produced, the operation of the apparatus is stopped, and the occurrence of the error is informed to the user in the state in which the cassette  1  is left in the inner part of the apparatus. In this time, it is preferable that the staying of the cassette  1  in the inner part of the apparatus and the necessity of the removal of the cassette  1  are informed together with an error message. In this time, it is preferable to display an action which the user should take to the error as an message together with the error information.  
         [0229]     As errors which can be produced other than the errors pertaining to the cassette  1  and the apparatus mechanism, an electrical error, an error related to software, a communication error, an optical error and the like can be considered. Even when these errors are produced, it is preferable to inform the user of the contents of the errors as an error message.  
         [0230]     In case of the apparatus to be used in a medical spot, when the apparatus has stopped owing to a defect, it is preferable not only to inform the user of the occurrence of the defect, but also to eliminate the defect immediately, and to restore the apparatus to be able to be used again.  
         [0231]     However, such the restoring work of the defect of the prior art radiographic image reading apparatus using a storage phosphor has been limited to the work of a service man. Consequently, when an defect is produced, the user is obliged to call a service man and to stop the radiation photographing service until the service man arrives.  
         [0232]     In a copy machine, a printer or the like, it has become common knowledge to install a user maintenance mechanism for enabling a user to release a jam when output paper causes the jam. As the reasons why such a user maintenance mechanism has not been realized in the radiographic image reading apparatus using a storage phosphor, the following causes can be considered.  
         [0233]     1) In case of the copy machine or a printer, because output paper are very cheap, the presupposition that the output paper which has caused a jam may be spoilt (maybe output again) can be concluded. However, in case of the radiographic image reading apparatus using a storage phosphor, a storage phosphor sheet is very expensive. Consequently, the presupposition that the storage phosphor sheet may be spoilt is not concluded. Because of such a restriction, the construction of the mechanism of the user maintenance is difficult.  
         [0234]     2) In a copy machine or a printer, even when the output paper which has caused a jam is spoilt, a copy or a print out can be performed again. On the contrary, the storage phosphor sheet used for a radiographic image reading apparatus stores image information of a patient. When the storage phosphor sheet is spoilt, it is necessary to perform re-photographing of the patient. However, the re-photographing makes the patient be exposed by superfluous radiation, which is very undesirable.  
         [0235]     Accordingly, in this embodiment, the user maintenance mechanism of a radiographic image reading apparatus, mainly a cassette jam releasing mechanism, is realized in the following configuration.  
         [0236]     As shown in  FIG. 6 , the apparatus body  2  is provided with the maintenance door  5 . By opening the maintenance door  5 , the user can access the inner part of the apparatus body  2 . Moreover, the rotation movement body  41  can be rotated to move to the position of a dotted line “d” with a hand operation. Thereby, the user can access a part more inside (on the sub-scanning mechanism  50  side) than the position of the rotation movement body  41 . The mechanism will be described by means of  FIGS. 6 and 7 . The-user opens a maintenance door lock  510  with a manual operation, and makes the maintenance door  5  an open state. When the maintenance door  5  is in its close state, an interlock killer  530  fixed on the maintenance door  5  acts on an interlock switch  96  fixed to the apparatus body  2 , and then the apparatus body  2  is in the state in which the apparatus body  2  can operate. However, when the maintenance door  5  becomes its open state, the interlock killer  530  comes out from the interlock switch  96 , and the interlock works to intercept the power source supply mainly to a mechanism actuating system of the motor, the sensors and the like, a laser actuating system, a high voltage power source system to the photomultiplier tube.  
         [0237]     In the inside of the maintenance door  5 , a rotation knob  49  is housed in a housing box  521 . The user takes out the rotation knob  49  from the housing box  521  to fit fitting holes  493  of a disk  492  of the rotation knob  49  to projections  463  of a cylinder member  462  fixed to a motor shaft  461  of the conveyance motor unit  46 .  
         [0238]     Next, when a rotation handle  490  of the rotation knob  49  is pinched and the rotation knob  47  is rotated clockwise, the pinion gear  47  rotates on the rack teeth  480  on the rugged form formed on the circular arc of the rotation support plate  48 . Then, the rotation movement body  41  rotates to move into the direction of the dotted line “d”. When the rotation movement body  41  has rotated to move to the position of the dotted line “d”, a space through which accessing to the inner part of the apparatus body  2  can be done is generated. Then, the user can take out the cassette  1  staying in the inner part of the apparatus body  2 .  
         [0239]     There are many cassettes  1  staying in the inner part of the apparatus body  2  in the form in which the front panels  10  and the back panels  20  unite with each other on the elevating platforms  43  chiefly. In this case, it is possible to taken out the cassettes  1  along the rotation movement body  41  immediately. In this case, because the storage phosphor sheets  28  are protected in the inner part of the cassettes  1 , it is possible that a cassette jam can be released without damaging the storage phosphor sheets  28 .  
         [0240]     As another case, there is a case where the back panel  20  resides on the magnet  58  and the front panel  10  resides on the rotation movement body  41 . In this case, after the back panel  20  has been peeled from the magnet  58  and has been superposed on the front panel  10  on the rotation movement body  41  at a normal position, both of the front panel  10  and the back panel  20  can be drawn out along the rotation movement body  41 . Because the back panel  20  is attracted to the magnet  58  only by the magnetic force, the back panel  20  can be easily peeled from the magnet  58  without performing superfluous operation. Moreover, because the apparatus is configured to be able to move up and down the sub-scanning movement plate  57  of the sub-scanning mechanism  50  with manual operations, the sub-scanning movement plate  57  can be manually operated to a position where the back panel  20  can be easily peeled from the magnet  58 . This case is characterized by the capability of keeping the state in which any mechanisms do not contact with the surface of the storage phosphor sheet  28  on the back panel  20 . Consequently, cassette jams can be released without injuring the surface of the storage phosphor sheet  28 .  
         [0241]     As the other case, there is the case where the front panel  10  is ejected to the ejection opening  4  and only the back panel  10  is remaining on the magnet  58 . In this case, the back panel  20  is peeled from the magnet  58 , and the peeled back panel  20  is taken out to the outside of the apparatus carefully. This case is also characterized by the capability of keeping the state in which no mechanisms contact wit the surface of the storage phosphor sheet  28  on the back panel  20 . Cassette jams can be released without injuring the surface of the storage phosphor sheet  28 .  
         [0242]     Moreover, even when the cassette  1 , the front panel  10  or the back panel  20  falls in the inner part of the apparatus body  2 , the fallen cassette  1 , the front panel  10  or the back panel  20  can be pick out by rotating and moving the rotation movement body  41  into the direction of the dotted line “d”.  
         [0243]     Because the positions of the elevating platform  43  and the width shifting member  42  can be changed with manual operations, the elevating platform  43  can be manually moved into the arrow A 2  direction (downward), or the width shifting members  42   a  and  42   b  can be moved into the arrow M 2  directions shown in  FIGS. 10A and 10B  when the upper section of the cassette  1  interferes with the insertion rollers  72   a  and  72   b , the ejection rollers  73   a  and  73   b , or the mechanism in the inner part of the apparatus to make it impossible that the rotation movement body  41  rotates to mover into the direction of the dotted line “d”. Consequently, the user can take out the cassette  1  in which a defect has been caused to the outside of the apparatus without using specific jig.  
         [0244]     Moreover, a feature of the apparatus is that the apparatus mechanism has no sections in which the cassette  1 , the front panel  10  or the back panel  20  is gripped or is held with strong force to the degree of making it impossible to take out one of them with manual operations. Although the insertion rollers  72   a  and  72   b  and the ejection rollers  73   a  and  73   b  grip the cassette  1 , the cassette  1  can be easily taken out because the insertion rollers  72   a  and  72   b  and the ejection rollers  73   a  and  73   b  rotate in a free state. Moreover, even in the state in which the cassette  1  is held by the width shifting members  42   a  and  42   b  in the inner part of the apparatus body  2 , the cassette  1  can be easily taken out because there are no parts where the width shifting members  42   a  and  42   b  and the cassette  1  are fitted to each other (because the cassette  1  is in the state in which the width shifting members  42   a  and  42   b  are only pressing from both sides of the cassette  1 ). Moreover, because the width shifting members  42   a  and  42   b  can be manually moved into the arrow M 2  directions shown in  FIGS. 10A and 10B , the cassette  1  can be taken out after being made to be in a free state on the elevating platform  43 .  
         [0245]     Moreover, when the cassette  1  is made to stay to be stopping in the inner part of the apparatus body  2  at the occurrence of an error, the apparatus is stopped after the rotation movement body  41  has been moved to the position of the dotted line “a” and the width shifting members  42   a  and  42   b  are moved to the positions of the waiting positions S 1 . Then, the display  81  performs error display. Thereby, the time necessary for user&#39;s taking out the cassette  1  can be minimized.  
         [0246]     Moreover, also when the back panel  20  resides on the magnet  58 , by making the sub-scanning movement plate  57  descend to the delivery position to the front panel  10  to stop the apparatus, the time necessary for a user to take out the cassette  1  can be minimized.  
         [0247]     Moreover, when the radiographic image reading apparatus is configured so that the position of the cassette insertion and ejection section  70  can be easily changed with manual operations (for example, the apparatus is configured so that the position of the cassette insertion and ejection section  70  can be manually slid or rotated to move into the upper direction, or configured so that the position of the cassette insertion and ejection section  70  can be manually rotated to move in the horizontal direction like a maintenance door, or configured so that the cassette insertion and ejection section  70  can easily removed with manual operations), the accessing space to the inner part of the apparatus is widened, and the maintenance work becomes easy to perform.  
         [0248]     One of the important errors which can be caused in this embodiment is an error of leaving the back panel  20  in the inner part of the apparatus body  2  and of ejecting only the front panel  10  (falling error of the back panel  20 ). This error is an defect produced by dropping the back panel  20  erroneously at the uniting work of the front panel  10  and the back panel  20 . Because there is no measure for confirming the result of uniting after the uniting work of the front panel  10  with the back panel  20  even if the defect has been produced, only the front pane  110  is ejected with the back panel  20  being left in the inner part of the apparatus body  2 . After that, when the next cassette  1  has been taken in the inner part of the apparatus and a series of operation has begun, not only the back panel  20  dropped in the inner part of the apparatus is broken, but also the apparatus mechanism is damaged. Accordingly, this embodiment settled the problem by the following measure.  
         [0249]     First, as shown in  FIG. 7 , the ejection roller  73   b  is formed to be a dumpling roller so as to form a space at the center section of the ejection roller  73   b , and a back panel falling detection mechanism is formed in the space. The back panel falling detection mechanism is composed of a back panel tracing rod  73   b   1  and a back panel falling detection sensor  73   b   2 . In the state in which the cassette  1  does not pass the ejection roller  73   b , the back panel falling detection sensor  73   b   2  outputs an ON signal. When the front panel  10  passes the ejection roller  73   b  with the back panel  20 , the tip of the back panel tracing rod  73   b   1  on the ejection opening  4  side inclines to the upper side, and the back panel falling detection sensor  73   b   2  outputs an OFF signal. When the cassette  1  has passed the ejection roller  73   b , the back panel falling detection sensor  73   b   2  again outputs the ON signal. That is, when the front panel  10  passes the ejection roller  73   b  with the back panel  20 , the back panel falling detection sensor  73   b   2  continues to output the OFF signal always during the front panel  10  is passing.  
         [0250]     However, when the front panel  10  has passed the ejection roller  73   b  without the back panel  20 , the tip of the back panel tracing rod  73   b   1  on the ejection opening  4  side once inclines to the upper side when the frame  11  part of the front panel  10  passes there. At this time, the back panel falling detection sensor  73   b   2  outputs the OFF signal. However, because the back panel  20  does not exist after that, the back panel falling detection sensor  73   b   2  again outputs the ON signal. That is, the back panel falling detection sensor  73   b   2  always continues to output the ON signal during the front panel  10  passes except for a short time when the frame  11  part of the front panel  10  passes. By catching the ON signal, the not shown control section can recognize that the back panel  20  is left in the inner part of the apparatus body  2 , and the control section can control the apparatus not to operate even when the next cassette  1  is inserted.  
         [0251]     The conveyance mechanism  40  in the embodiment shown in  FIG. 6  includes at least two kinds of conveyance mechanism of a linear conveyance mechanism (a mechanism for linearly conveying the cassette  1  into up and down directions along the rotation movement body  41  of the conveyance mechanism  40 ) by the elevating platform  43 , and a rotation conveyance mechanism for rotating and moving the cassette  1  around the rotation shaft  45  as the rotation center.  
         [0252]      FIG. 6  shows an example realizing the two conveyance mechanisms of the linear conveyance mechanism and the rotation conveyance mechanism on the rotation movement body  41 . However, for example, the two conveyance mechanisms of the linear conveyance mechanism and the rotation conveyance mechanism may be realized by individual mechanisms. For example, the radiographic image reading apparatus may be configured so that the rotation conveyance mechanism rotates to move independent of the linear conveyance mechanism.  
         [0253]     Moreover, the rotation conveyance mechanism may be configured so that a part of the conveyance mechanism  40  (rotation movement body  41 ) rotates to move.  
         [0254]     Moreover, the rotation conveyance mechanism may be configure by being divided into a plurality of rotation conveyance mechanisms.  
         [0255]     Similarly, a linear conveyance mechanism may be configured by being divided into a plurality of linear conveyance mechanisms.  
         [0256]     Moreover, the embodiment shown in  FIG. 6  is configured to separate the front panel  10  and the back panel  20  after the back panel back surface  210  of the back panel  20  has been attracted to the magnet  58 . However, the embodiment may be configured to make the back panel back surface  210  of the back panel  20  be attracted to the magnet  58  after the front panel  10  and the back panel  20  have been separated from each other.  
         [0257]     Moreover, the embodiment of  FIG. 6  is configured to separate the front panel  10  and the back panel  20  from each other after rotating and moving the cassette  1 . However, the embodiment may be configured to rotate to mover only the back panel  20  after separating the front panel  10  and the back panel  20  from each other.  
         [0258]     Moreover, the embodiment of  FIG. 6  is configured to deliver the back panel  20  to the sub-scanning mechanism  50  by means of the rotation and movement of the rotation movement body  41 . However, the embodiment may be configured to deliver the back panel  20  to the sub-scanning mechanism  50  by the rotation and the movement of a part or the whole of the sub-scanning movement plate  57 .  
         [0259]     Moreover, in the embodiment of  FIG. 6 , the conveyance mechanism  40  and the sub-scanning function  50  are constructed on the same substrate  92 , and the substrate  92  is fixed to the base plate  91  with the rubber vibration isolator  93  between them. However, the embodiment may be configured so that the convey mechanism  40  and the sub-scanning function  50  are constructed on different substrates and the respective substrates are fixed to the base plate  91  with the rubber vibration isolator  93  put between them, or that the conveyance mechanism  40  is directly constructed on the base plate  91 . Thereby, it can be prevented that vibrations generated by the operation of the conveyance mechanism  40  are propagated to the sub-scanning mechanism  50 .  
         [0260]     Moreover, the embodiment of  FIG. 6  may be configured so that the back panel  20  is absorbed to the sub-scanning movement plate  57  equipped with an absorption member such as vacuum. In this case, the back surface of the back panel back surface  210  is unnecessary to be a magnetic substance, an the magnet  58  on the sub-scanning movement plate  57  is also unnecessary.  
         [0261]     Moreover, the embodiment of  FIG. 6  may be configured so that only one of the insertion opening  3  and the ejection opening  4  of the cassette insertion and ejection section  70  can be demounted from a conveyance read section  2   a , or that the position can be changed with manual operations. Moreover, the embodiment may be configured so that the insertion opening  3  and the ejection opening  4  of the cassette insertion and ejection section  70  can be individually removed, or the positions can be individually changed with manual operations.  
         [0262]     The entire disclosure of Japanese Patent Application No. Tokugan 2002-237700 filed on Aug. 16, 2002 including specification, claims drawings and summary are incorporated herein by reference in its entirety.