Abstract:
An image forming apparatus includes a heating drum image forming material supply device that feeds the image forming material in the form of a roll and winds the image forming material to the heating drum, a photosensitive material supply device that feeds the photosensitive material in the form of a roll and conveys the photosensitive material to an exposure section, and a laminating section which laminates the photosensitive film and image forming film onto the heating drum, and a take up device for the used photosensitive material.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming apparatus that thermally transfers an image that has been formed by exposing a photosensitive material, from the photosensitive material to an image-receiving material. 
     2. Description of the Related Art 
     A thermal transfer-type image forming apparatus transfers an image on a photosensitive material, which image was formed through imagewise exposure, to an image-receiving material. This type of image forming apparatus is ordinarily structured such that the photosensitive material is pulled out a predetermined length from a magazine, cut into the form of a sheet, and then sent to an exposure section. 
     After applying water to the photosensitive material that has been exposed at the exposure section, the photosensitive material is laminated with the image-receiving material and wound at a heating drum to be pressed against the heating drum for a predetermined period of time with an endless belt, thereby thermally transferring an image from the photosensitive material to the image-receiving material. 
     However, with such a structure, there is the necessity of making the diameter of the heating drum large in accordance with the size of the image to be transferred, and in conjunction, the length of the endless belt must be long. Therefore, the apparatus cannot be made compact. 
     Further, with such a structure, after the image has been transferred, disposing of the sheet-form photosensitive material in a bundled state is difficult. 
     SUMMARY OF THE INVENTION 
     The present invention was achieved in light of the above-described circumstances, and an object thereof is to make processing of used photosensitive material easy and to allow the size of an image forming apparatus to be reduced. 
     In the present invention, a photosensitive material supplying device pulls out a photosensitive material, which is in the form of a roll, and feeds it to an exposure section. The photosensitive material is exposed at the exposure section. Thereafter, a solvent is applied to the photosensitive material by an application device, and the photosensitive material is conveyed to a heating drum. 
     An image-receiving material supplying device pulls out an image-receiving material, which is in the form of a roll, cuts it to a desired size, and winds it at a heating drum. Simultaneously, at the heating drum, a laminating device laminates the image-receiving material and the photosensitive material, to which a solvent has been applied. 
     The heating drum, at which the photosensitive material and the image-receiving material have been wound, is rotated without being stopped, and while the photosensitive material and the image-receiving material are conveyed, an image on the photosensitive material is thermally transferred to the image-receiving material. Accordingly, the time taken for the image-receiving material, which has had the image thermally transferred thereto, to be discharged from the image forming apparatus is reduced. 
     Increasing the radius of the heating drum in accordance with the size of the image to be thermally transferred is not necessary as it is in conventional image forming apparatuses. An endless belt is also not necessary. Accordingly, the apparatus can be made compact. 
     Further, since the photosensitive material is conveyed from the photosensitive material-supplying device to a take-up device without being cut, the photosensitive material itself functions as an endless belt that applies a fixed pressure. 
     Since the photosensitive material that has been laminated with the image-receiving material is taken up by the take-up device without being cut into sheet-forms, processing of the used photosensitive material is made easy. 
     In the present invention, the laminating device preferably comprises: laminating rollers that rotate around the heating drum in a state where the photosensitive material and the image-receiving material are interposed between the laminating rollers and the heating drum; and a stripping device that strips a trailing-end side of the photosensitive material off from the heating drum, in conjunction with rotation of the laminating roller. 
     Taking as an example a case where image processing is carried out for a single sheet, the image-receiving material is conveyed to the heating drum after being cut into a sheet-form, which does not cause problems. The photosensitive material, however, continuously extends until the photosensitive material supplying device, since it is taken up by the take-up device. 
     When the photosensitive material is conveyed without being cut, after the image is transferred to the image-receiving material, regions of the photosensitive material that have not been exposed imagewise may contact the heating drum as the heating drum rotates. These regions of the photosensitive material can not be used for the subsequent image processing. 
     Accordingly, in a preferred embodiment of the present invention a structure has been adopted wherein the laminating rollers rotate about the heating drum with the photosensitive material and the image-receiving material interposed between the heating drum and the laminating rollers. The stripping device strips the trailing-end side of the photosensitive material off from the heating drum, in conjunction with movement of the laminating roller. 
     Namely, while maintaining a state in which the trailing end portion of the sheet-form image-receiving material and the photosensitive material are laminated together with the laminating rollers, the stripping device strips away from the heating drum the side of the photosensitive material towards the photosensitive material supplying device. Accordingly, the photosensitive material that has not yet been exposed does not contact the heating drum, and can be used in the next image formation processing. 
     In the present invention, a swinging device preferably supports an application unit provided with an application portion for applying a solvent, such that the application unit can be swung. A driving device rotates the application unit while causing the application portion to contact the photosensitive material at an angle such that the entire surface of the application portion is gradually brought into contact with the photosensitive material. Air is removed from between the surface of the photosensitive material and the application portion, thereby preventing uneven application. 
     According to another aspect of the present invention, the take-up device comprises: a core; a holding member swingably attached to the core, for holding an end portion of the photosensitive material against the core; an engaging pawl protruding from the core for penetrating the photosensitive material and passing therethrough; a flange provided at two ends of the core, at least one of the flanges being detachable; and a releasing device for collapsing the engaging pawl when the photosensitive material has been wound around the core, and is to be pulled therefrom in an axial direction of the core. 
     According to this structure, the holding member is collapsed toward the core, and an end portion of the photosensitive material is thereby held down by the holding member. The engaging pawl that is provided at the core so as to protrude therefrom is made to pass through the photosensitive material. Accordingly, the photosensitive material does not become removed from between the core and the holding member. 
     The flange that is provided at each of the two ends of the core prevents the photosensitive material from shifting sideways when the photosensitive material that has been used is taken up. At least one of the flanges is attached such that detachment is possible. After all of the used photosensitive material is taken up, the flange can be removed, and the photosensitive material, which is in the form of a roll, can be pulled out in the shaft direction of the core. 
     At this time, the releasing device functions to collapse the engaging pawl, which has been passed through the photosensitive material. Accordingly, the photosensitive material, which is in the form of a roll, can be removed without using much force. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view showing an entire structure of an image forming apparatus according to an embodiment of the present invention, and an operating procedure thereof. 
     FIG. 2 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 3 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 4 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 5 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 6 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 7 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 8 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 9 is a side view showing the entire structure of the image forming apparatus according to the present embodiment, and an operating procedure thereof. 
     FIG. 10 is a side view showing a water application section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 11 is a side view showing the water application section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 12 is a side view showing the water application section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 13 is a view showing the water application section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 14 is a side view showing the water application section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 15 is a side view showing a thermal development section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 16 is a side showing the thermal development section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 17 is a side view showing the thermal development section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 18 is a side view showing the thermal development section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 19 is a side view showing the thermal development section of the image forming apparatus according to the present embodiment, and movement thereof. 
     FIG. 20 is a perspective view showing a disposal reel of the image forming apparatus according to the present embodiment. 
     FIG. 21 is a perspective view showing the disposal reel of the image forming apparatus according to the present embodiment. 
     FIG. 22 is a cross-sectional view showing the disposal reel of the image forming apparatus according to the present embodiment. 
     FIG. 23 is a perspective view showing the disposal reel of the image forming apparatus according to the present embodiment. 
     FIG. 24 is a perspective view showing the disposal reel of the image forming apparatus according to the present embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An image forming apparatus  10  according to the present embodiment is shown in FIG.  1 . 
     A supply reel  16  around which a photosensitive material  18  is wound is set in a photosensitive material magazine  14  disposed at a lower side of a housing  12  of the image forming apparatus  10 . 
     A top cover  19  of the photosensitive material magazine  14  is structured so that opening and closing thereof is possible. A nip roller  20  is attached to a portion at the free end of the top cover  19 . When the top cover  19  is closed, the nip roller  20 , together with a nip roller  22  attached to the main body of the photosensitive material magazine  14 , nips the photosensitive material  18 , and conveys the photosensitive material  18  to a platen roll  26  (to be described later) via a guide plate  24 . 
     Further, in a vicinity of a pull out opening of the guide plate  24 , a light-shielding member  28  is provided, to prevent the photosensitive material  18  from fogging. Further, between the nip rollers  20 ,  22  and the light-shielding member  28 , a sensor  30  is disposed, which detects the presence or absence of a buffer B 2  and measures the timing at which the photosensitive material  18  is conveyed out. The speed at which the photosensitive material  18  is conveyed does not vary due to forming the buffer. 
     After the photosensitive material  18  is conveyed past the guide plate  24 , the photosensitive material  18  is wound at the platen roll  26 , which rotates, and imagewise exposure is carried out with a scanning head  32 . 
     Three LED chips of R (red), G (green), B (blue) (these may be light sources such as an LED or the like), which are lit in accordance with signals from a control section in which image signals are recorded, are disposed on the scanning head  32 . Light from the LED chips is condensed with a condenser lens structured by a plurality of lenses and an aperture stop, and is focused on the photosensitive material  18  to form an image. By winding the photosensitive material  18  at the platen roll  26  and exposing the photosensitive material  18  in this way, creases are prevented from forming on the photosensitive material  18  in the transverse direction thereof, and planarity of the exposure surface can be ensured. 
     Driving of the scanning head  32  is synchronized with step-driving (driving the platen roll  26  and conveying rollers) of the photosensitive material  18 . Namely, after the photosensitive material  18  undergoes step movement and is then brought to a standstill, the scanning head  32  moves along shafts  34 ,  36  in the transverse direction of the photosensitive material  18  (main scanning direction). After the photosensitive material  18  undergoes further step movement and is then brought to a standstill, main scanning in the reverse direction is carried out. 
     Next, the photosensitive material  18 , which has been exposed to form an image, is conveyed out to a water application section by a nip roller  38 . At this water application section, a casing  40 , which is supported so as to be swingable, is disposed. This casing  40 , as illustrated in FIG. 10, is structured so as to be able to rise and rotate 180° C., and an application unit  42  can be easily disconnected from an aperture portion thereof. 
     A sponge  44  is attached at an application surface of the application unit  42 . The sponge  44  squeezes out a fixed amount of water, regardless of the amount of water in a water tank (not illustrated). Accordingly, water droplets do not fall upon the photosensitive material  18 , and excess water is not applied to the photosensitive material  18 . 
     Further, an upper portion of the application unit  42  is supported at the casing  40  such that the application unit  42  can swing. As illustrated in FIG. 11, when the sponge  44  is lowered, a corner portion thereof initially presses against the photosensitive material  18 . As illustrated in FIG. 12, operation is carried out so that the entire surface of the sponge  44  is gradually made to press against the photosensitive material  18 . Consequently, air can be prevented from becoming entrained between the sponge  44  and the photosensitive material  18 . 
     At a lower side of the application unit, a surface heater  46 , which faces the sponge  44 , is provided horizontally. Water is applied to the photosensitive material  18  with the sponge  44  as the photosensitive material  18  is conveyed across the top of the surface heater  46 . Further, a distal end portion of the surface heater  46  is bent diagonally downward toward the platen roll  26 , so that a corner portion of the surface heater  46  does not scratch the photosensitive material  18 . At an upstream side of the surface heater  46 , a flocked friction pad  48  is provided. The photosensitive material  18  is interposed between the flocked friction pad  48  and the surface heater  46 . The function of forming buffers B 3 , B 4  between the flocked friction pad  48  and the nip roller  38  is thereby carried out by the flocked friction pad  48 . 
     The buffers B 3 , B 4  are detected by a buffer detecting device. This buffer detecting device is structured by a lever portion  52  which is axially supported by a pin  50 , and an arm portion  56 , which bends from the distal end of the lever portion  52  and extends so as to pass through a photo-sensor  54 . 
     A torsion coil spring (not illustrated) is attached at the pin  50 , and energizes the lever portion  52  in the clockwise direction. As shown in FIG. 12, when the buffer is formed, an end portion of the arm portion  56  is separate from the photo-sensor  54 . A structure has been adopted wherein as the buffer becomes smaller, the lever portion  52  is pressed by a reverse surface of the photosensitive material  18  to rotate in the counter-clockwise direction, and the arm portion  56  passes through the photo-sensor  54 , as shown in FIG.  14 . 
     With this kind of structure, during standby (the time when image forming is not being carried out) the buffer B 3 , B 4  is not formed, and the end portion of the arm portion  56  is in a position shown in FIG.  14 . Then, in order to position the leading end portion of the photosensitive material to be exposed next, the photosensitive material is conveyed by the platen roll  26 , the buffer B 3  shown in FIG. 12 is formed, and conveyance is stopped when the end portion of the arm portion  56  is separate from the photo-sensor  54 . 
     Next, the photosensitive material is conveyed, the buffer B 3  is made smaller and the buffer B 4  is formed, as shown in FIG.  13 . Conveyance is stopped when the end portion of the arm portion  56  passes through the photo-sensor  54 . As a result, the length of the photosensitive material  18  between a laminating roller  58  (to be described later, see FIG. 1) and the nip roller  38  is fixed, and the portion of the photosensitive material  18  to be exposed next can be positioned. 
     Further, although the surface heater  46  is heated to approximately 40° C., there are no problems in terms of quality even if the photosensitive material  18  comes into contact therewith. Image quality is not affected even if the photosensitive material  18  is pulled back and then exposed. 
     As shown in FIG. 1, the photosensitive material  18  is guided by a turn roller  60  that is axially supported so as to be rotatable, and is wound with a fixed pressure about a heating drum  64 , by the laminating roller  58  and a stripping turn roller  62 . The heating drum  64  has built therein a halogen lamp, an infrared ray heater, or the like. Here, an image-receiving paper  66 , which will be described later, is laminated onto the top surface of the photosensitive material  18 . The photosensitive material  18  and the image-receiving paper  66  are then wound at the heating drum  64  and conveyed while being heated, so that an image is thermally transferred. In this way, tension is imparted to the photosensitive material  18  with the laminating roller  58  and the stripping turn roller  62 . As a result, an endless belt, which is used conventionally, is unnecessary. Further, since thermal transfer is carried out during conveyance with the rotating heating drum  64 , there is no need to change the radius of the heating drum in accordance with the image size. 
     The image receiving paper  66  that has been wound around a supply reel  70  is set in an image-receiving material magazine  68 . The image receiving paper  66  is then pulled out with nip rollers  72 , and after being cut into a predetermined length with a cutter  74 , is guided to conveying rollers  76  and a guide plate  78 . The leading end portion of the image receiving paper  66  is made to standby at positioning rollers  80 , is aligned with the laminating roller  58 , and thereafter, is laminated onto the photosensitive material  18 . 
     Next, details of a thermal transfer developing section will be given. 
     As shown in FIG. 15, a fan-shaped rotating arm  82  extends in the radial direction at each of two end portions of the heating drum  64 . A center portion of the rotating arm  82  is supported at a shaft portion of the heating drum  64  so as to be rotatable. This rotating arm  82  is structured so as to rotate with a timing that will be described later, due to a driving mechanism (not illustrated). 
     Pulling rollers  84 ,  86 ,  88  are rotatably supported at the rotating arm  82 , along an arc that is concentric with the heating drum  64 . As shown in FIG. 15, when the rotating arm is in a standby position, the image receiving paper  66  passes between the pulling roller  84 ,  86  to be wound at the heating drum  64 . 
     Further, a guiding groove  90  is formed in an arc-form that is concentric with the heating drum  64 , at a periphery of the heating drum  64 . A shaft portion of the laminating roller  58  is guided by the guiding groove  90 , and the laminating roller  58  moves about the heating drum  64  while pressing the photosensitive material  18  and the image receiving paper  66  onto the heating drum  64 . 
     Further, the laminating roller  58  is connected with the rotating arm  82  by a connecting member (not illustrated), and is structured so as to move along the guiding groove  90  integrally with the rotating arm  82 . 
     Next, operation of the thermal transfer developing section will be explained. 
     As shown in FIG. 15, during continuous printing, the leading end portion of the sheet-form image receiving paper is brought to a temporary standstill by the positioning rollers  80  and is positioned, and is then aligned at a nipping position between the laminating roller  58  and the heating drum  64 . 
     Next, the image receiving paper  66  and the photosensitive material  18  is laminated at the heating drum  64  with the laminating roller  58  and the stripping turn roller  62 . As the image receiving paper  66  and the photosensitive material  18  are conveyed while being heated, the image on the photosensitive material  18  is thermally transferred to the image receiving paper  66 . 
     In this way, in the case of continuous printing, thermal transfer processing is carried out in a state in which the laminating roller  58  and the rotating arm  82  are kept at a standstill without being moved. 
     After continuous printing is ended, or in a case in which only one sheet was printed, if the photosensitive material  18  is conveyed out as is the following occurs. When thermal transfer to the image receiving paper  66  is effected, regions of the photosensitive material  18  on which an image has not been formed through imagewise exposure contacts the heating drum  64  as the heating drum rotates, and these regions can not be used in the subsequent image processing. 
     Therefore, after a trailing end portion of the image receiving paper  66  contacts the heating drum  64  as shown in FIG. 16, the rotating arm  82  and the laminating roller  58  move about the heating drum  64  along the guiding groove  90  at the same rotating speed as the heating drum  64 , with the photosensitive material  18  and the image receiving paper  66  interposed between the laminating roller  58  and the heating drum  64 , as shown in FIG.  17 . 
     As a result, as shown in FIG. 18, the pulling rollers  84 ,  86 ,  88  pull the trailing end side of the photosensitive material  18  apart from the heating drum  64 , in conjunction with movement of the laminating roller  58 . 
     Accordingly, the photosensitive material  18  that has not yet been exposed does not contact the heating drum  64 , and can be used in the next image formation. 
     As shown in FIG. 19, after the laminating roller  58  moves until it reaches an end portion of the guiding groove  90 , the image receiving paper  66  and the photosensitive material  18  which has been laminated together are separated at the location of the stripping turn roller  62 , and the image receiving paper  66 , which is towards the heating drum  64 , is stripped from the heating drum  64  with a stripping pawl (not illustrated). Then, the image receiving paper  66  which has been stripped from the heating drum  64  is guided to conveying rollers  94  and a guide plate  96 , and is conveyed to a pan  98  (see FIG.  1 ). 
     At this time, nipping action of the laminating roller  58  is released, the nip rollers  20 ,  22  rotate in the reverse direction, and the photosensitive material  18  that has not yet been used is pulled back. Thereafter, the rotating arm  82  and the laminating roller  58  returns to the state shown in FIG. 15, and waits for the next thermal transfer instruction. 
     The photosensitive material  18  from which an image has been transferred and which has been used is conveyed by nip rollers  102 ,  104 , and is wound about a disposal reel  100 . In this way, since the photosensitive material  18  is conveyed to the disposal reel  100  from the supply reel  16  without being cut, the photosensitive material  18  itself functions as an endless belt that applies fixed pressure to the image receiving paper  66 . Further, since the photosensitive material  18  is wound without being cut into the form of sheets, processing of the photosensitive material  18  that has been used is simplified. 
     Here, a structure of the disposal reel  100  will be explained. 
     As shown in FIGS. 20 to  22 , a substantially cylindrical core  106  is provided, a portion of the peripheral surface of which being cut in a flat plane along the shaft direction, as an interposing face  108 . A shaft portion  112  having a small diameter is formed at an end portion of this core  106 . This shaft portion  112  is fit into a fitting hole  118  formed in a cylindrical flange  116 . 
     A wide relief groove  120  is formed at an inner side of the flange  116 , from an intermediate portion thereof toward a radial direction (direction moving away from the interposing face  108 ). A pin  122  is provided in a protruding condition at a groove wall of the relief groove  120 . An end of a crescent-shaped holding member  124  is rotatably connected to this pin  122 . 
     A pressing face  126  is formed at the holding member  124 , which holds the photosensitive material  18  against the interposing face  108  when the holding member  124  is collapsed towards the core  106 . Further, as shown in FIG. 20, the holding member  124 , when stood upright, is made to fit into the relief groove  120  in an upright position, so as not to be an obstruction when the photosensitive material  18  is set on the interposing face  108 . 
     At an intermediate portion of the pressing face  126 , a long aperture  128  is formed. As shown in FIG. 22, when the holding member  124  is collapsed toward the core  106 , an engaging pawl  130  that pierces through the photosensitive material  18  engages with the long aperture  128 . 
     The engaging pawl  130  is supported with a pin  132  provided at an internal portion of the core  106 , such that the engaging pawl  130  can swing in the shaft direction of the core  106  (within the long aperture  128 ). An extension spring  136 , one end of which is fixed by a pin  134 , is connected to a lower end side of the engaging pawl  130 . The extension spring  136  energizes the engaging pawl  130  such that the engaging pawl  130  rotates in the counterclockwise direction with the pin  132  as the center of rotation. 
     Due to this structure, the engaging pawl  130  is ordinarily maintained in an upright condition. When the photosensitive material  18  is pulled in the left/right direction, the engaging pawl collapses toward the long aperture  128  and is separated from the photosensitive material  18 . 
     A free end side viewing from the long aperture  128  of the holding member  124  is slightly thinner, and when the photosensitive material  18  is held between the holding member  124  and the interposing face  108 , space is left therebetween. An engaging body  138  is provided at a free end portion of the holding member  124  so as to protrude therefrom. When the holding member  124  is inclined toward the core  106  side, this engaging body  138  enters a guiding hole  140  (to be described later) formed in the flange  114 , passes over a partition portion  142 , and enters a locking hole  144 , and the holding member  124  is thereby locked. 
     A substantially triangular-pole-shaped boss  146  is provided at the flange  114  so as to protrude towards an outer side thereof. A cone-shaped shaft portion  110 , which is provided so as to protrude from the other end portion of the core  106 , is inserted from an inner side of the boss  146 . 
     Cam grooves  148  are formed in a spiral form at an outer peripheral surface of the shaft portion  110 . When the shaft portion  110  is inserted into the boss  146 , a lock pin  150 , which is provided at the boss  146  so as to protrude from an inner side thereof, enters the cam groove  148 . In conjunction with rotation of the boss  146 , the flange  114  is guided to a locked position. 
     Further, the fan-shaped locking hole  144  is formed at a periphery of the boss  146 . When the boss  146  is rotated, a wall forming the locking hole  144  locks the engaging body  138  of the holding member  124 . 
     Next, a method of handling the disposal reel  100  will be explained. 
     As shown in FIG. 20, the holding member  124  is placed in an upright position, and a leading end portion of the photosensitive material  18 , which has been unwound from the supply reel  16 , is pressed against the engaging pawl  130  so that the engaging pawl  130  passes therethrough. The photosensitive material  18  is thus prevented from inadvertently coming apart from the core  106 . 
     Next, as shown in FIG. 21, the holding member  124  is collapsed toward the core  106 . When the photosensitive material  18  is held between the interposing face  108  and the pressing face  108 , a distal end portion of the engaging pawl  130  enters the long aperture  128 . 
     Here, the flange  114  is attached to the shaft portion  110 , by matching the respective positions of the lock pin  150  and the cam groove  148 , and then turning the boss  146  clockwise. Accordingly, the wall forming the locking hole  144  moves to a position where it presses down the engaging pawl  138  of the holding member  124 , and the flange  114  is fastened at the shaft portion  110 . 
     As shown in FIG. 23, in order to remove the photosensitive material  18 , which has been used and is wound around the disposal reel  100 , from the core  106  and the holding member  124 , the boss  146  is first rotated counter-clockwise (the direction of arrow A). As a result, the lock pin  150  becomes disengaged by being slid along the cam groove  148 . As shown in FIG. 24, the flange  114  can then be removed from the shaft portion  110 . 
     When the photosensitive material  18 , which has been used and is in the form of a roll, is pulled out in the direction of the shaft (i.e., the direction of arrow B), the engaging pawl  130  is collapsed in the direction of arrow C in FIG.  22  and is separated from the photosensitive material  18 . Thus, the photosensitive material  18  can be easily removed, i.e., substantial removal force is not required. 
     Next, a procedure of exchanging the photosensitive material  18  will be explained, with reference to FIGS. 3 to  9 . 
     After the photosensitive material  18  is completely taken up by the disposal reel  100  from the supply reel  16  as shown in FIG. 3, an upper body section  10 A of the image forming apparatus  10  is opened, by pivoting the upper body section  10 A with a hinge portion  152  as a center. At this time, an air damper  154  operates to push upwards the upper body section  10 A. Therefore, excessive force is not necessary to maintain the released state of the upper body section  10 A. A disposal magazine  156  is then opened, and the disposal reel  100  is removed. 
     Next, as shown in FIG. 5, the photosensitive material  18 , which has been wound into the form of a roll, is removed from the disposal reel  100 . Since details of this procedure have been already explained, further explanation will be omitted. 
     As shown in FIG. 6, the disposal reel  100  from which the used photosensitive material  18  has been removed is loaded into the disposal magazine  156 . The top cover  19  of the photosensitive material magazine  14  is opened, and the empty supply reel  16  is removed. 
     Next, as shown in FIG. 7, the new supply reel  16  having the photosensitive material  18  wound around it is loaded into the photosensitive material magazine  14 , and the top cover  19  is closed. In conjunction with the photosensitive material  18  being nipped by the nip rollers  20 ,  22 , the photosensitive material  18  is shielded from light by the light-shielding member  28 . At this time, a leading end portion of the photosensitive material  18  is pulled out to a degree where it emerges from the photosensitive material magazine  14 . 
     Next, as shown in FIG. 8, the photosensitive material  18  is wound at the platen roll  26 , and the leading end portion of the photosensitive material  18  is fastened between the core  106  and the holding member  124  of the disposal reel  100 . 
     Thereafter, as shown in FIG. 9, the disposal magazine  156  is closed, and the photosensitive material  18  is taken up a predetermined amount by the disposal reel  100 . As a result, the photosensitive material  18  is made to hang across the platen roll  26 , the surface heater  46 , the turn roller  60 , the stripping turn roller  62 , and the nip roller  104 . 
     Thereafter, as shown in FIGS. 1 and 2, when the upper body section  10 A is closed, the photosensitive material  18  is interposed between the nip roller  38  and the platen roll  26 , and is wound at a portion of the heating drum  64 . After a buffer is formed, image formation becomes possible. 
     In the present embodiment, the supply reel was directly replaced. However, a photosensitive material roll may be removed from its outer packaging material and placed into the magazine. Thereafter, the cover is locked, the photosensitive material is pulled out until the leading end portion emerges, and the magazine is loaded into the image forming apparatus.