Abstract:
A toner cartridge having toner agitating and mixing properties. The structure insures image quality without increasing in complexity of the structure as well as capable of being compacted. A used toner recycling opening for dropping used toner by gravity is formed in an upper wall of a cartridge main body storing fresh toner. A toner agitator and a toner supply device with an opening for supplying mixed toner to a developing apparatus are arranged within the cartridge main body. The toner can be sufficiently mixed and agitated on a cartridge main body side without depending on a developing apparatus side, and the toner cartridge is prevented from being large-sized. In particular, since the used toner drops by gravity, a taking-in structure of this used toner is simplified, and a mixing work of the used toner with fresh toner is made irrespective of a moving direction of the toner agitator. Also, there are two film sealing members for sealing the used toner recycling and toner supply openings.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a toner cartridge in relation to an image forming apparatus using an electrophotographic process such as a digital copying machine, a printer and a facsimile apparatus, and more particularly a toner cartridge detachably connected to a developing apparatus. 
     2. Description of the Related Art 
     In a generally-used image forming apparatus, for the purpose of simplifying an operation of replenishing toner, a toner cartridge which is filled with toner in advance and is detachably mounted to a developing apparatus, is used, and which toner cartridge can be replaced with a new one when all the toner stored in the toner cartridge is used up. 
     However, recycling of resources has been drawing more attention than ever. An increasing number of image forming apparatuses using an electrophotographic process have been equipped with a so-called toner recycling function in which left-over toner on a photoconductor drum after an image transfer process is removed by a cleaner and collected as used toner to be reused in the developing apparatus. By using such a function, it is possible to extend a replacement cycle of toner cartridges. 
     In a conventional image forming apparatus having the toner recycling function shown in FIG. 5, fresh toner is supplied from a toner cartridge  101  detachably mounted to a developing apparatus  100 . Further, used toner in the developing apparatus  100  is collected in a process unit  102 , and is released to a releasing portion  103  of the process unit  102 . The used toner released at the releasing portion  103  is conveyed to the developing apparatus  100  through a conveying path  104 . 
     Further, as shown in FIG. 6, there is another prior art providing a structure that a downstream end of a toner supplying path  105  extended from the toner cartridge  101 , in which fresh toner passes through, is connected to a downstream end of a conveying path  104  extended from the process unit  102 , so that the fresh toner is joined with the used toner and the joined toner is then supplied to the developing apparatus  100 . 
     In the former prior art, the collected used toner is supplied to the developing apparatus  100  without any treatment. In this case, it is difficult to sufficiently mix the fresh toner with the used toner within the developing apparatus  100 . In the latter prior art, the collected used toner and fresh toner are joined together to be supplied to the developing apparatus  100 . However, in this case, too, the mixing process of the joined toners depends on an agitating operation within the developing apparatus  100 . Accordingly, it is also not easy to obtain a preferable mixing state. 
     Japanese Unexamined Patent Publication JP-A 9-212055 (1997) discloses a construction for actively mixing both toners as shown in FIG.  7 . In this construction, a toner mixer  106  is provided to mix the used toner t released from the process unit  102  with the fresh toner T supplied from a toner cartridge main body  101 A. In this case, toners T, t mixed inside the toner mixer  106  are supplied to the developing apparatus  100 . 
     However, in the construction of the above publicly known example, the toner mixer  106  is provided separately from the toner cartridge main body  101 A so that an additional accommodation space must be created, and thus the entire structure becomes large. As such, it is not likely to willingly adopt such a construction. 
     In consideration of such a situation, Japanese Unexamined Patent Publication JP-A 9-251230 (1997) discloses a construction as shown in FIG.  8 . In this construction, a used toner collecting port  110  is formed in a lower portion of a side wall  101   a  of the cartridge main body  101 A, and a toner replenishing port  111  is formed in a bottom wall  101   b  of the cartridge main body  101 A. A toner agitator  112  and a rotating body  113  for conveying toner are arranged within the cartridge main body  101 A. The used toner t conveyed from the used toner collecting port  110  by a toner taking-in mechanism  114  is mixed with the fresh toner T by the toner agitator  112 . The mixed toner is supplied to the developing apparatus  100  through the toner replenishing port  111  by the rotating body  113  to replenish the toner. 
     In the case of JP-A 9-251230, it may be possible to downsize the construction, however, the used toner collecting port  110  arranged in the lower portion of the side wall  101   a  of the cartridge main body  101 A requires an additional structure of taking-in mechanism  114  in order to convey the used toner t in a horizontal direction from the used toner collecting port  110 . Further, as a result of such a structure, it is also required to provide additional structures such as a sealing mechanism, resulting in complication of the entire structure. Further, since the used toner t is conveyed horizontally, there is such a problem that reliable agitating and mixing states cannot be obtained easily unless a moving direction of the toner agitator  112  and so on are adequately set. 
     Further, as shown in FIG. 9, Japanese Unexamined Patent Publication JP-A 5-80653 (1993) discloses a seal member  204  provided in a toner hopper  201 , wherein one end of the seal member  204  blocks a toner supply port  202  and the other end thereof is secured to a rotary shaft  203   a  of an agitating member  203 . When the invention is used, the seal member  204  is rolled up by rotating of the agitating member  203 . 
     However, in the construction of JP-A 5-80653, the seal member  204  rolled up by the agitating member  203  is collected inside the toner hopper  201 . In this case, there is a possibility that the sealing member is subject to sag or peel off during rotation of the agitating member  203 , which will result in a deficiency in toner agitating and conveying properties. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to solve the above problems and to provide a toner cartridge having excellent toner agitating and mixing properties. The toner cartridge results in improved image quality without increasing in complexity of the structure as well as being compact. 
     In order to solve the above-mentioned problem, the invention has the following construction. 
     The invention provides a toner cartridge detachably mounted to a developing apparatus, comprising: 
     a cartridge main body for containing toner, having a used toner recycling opening formed in an upper portion thereof via which conveyed used toner is dropped by gravity and is received into the cartridge main body, the toner cartridge being mounted to the developing apparatus in a state where the cartridge main body is filled with toner; 
     toner agitating means arranged within the cartridge main body, for agitating and mixing used toner and fresh toner; and 
     toner supply means arranged within the cartridge main body, for supplying agitated toner to the developing apparatus via a toner supply opening formed in the cartridge main body. 
     According to the invention, the conveyed used toner drops by gravity into the cartridge main body from the used toner recycling opening in the upper portion of the cartridge main body. Accordingly, the fresh toner and the used toner are efficiently agitated and mixed by the toner agitating means arranged within the cartridge main body. The agitated and mixed toner is supplied to the developing apparatus through the toner supply opening by the toner supply means arranged within the cartridge main body. Thus, a sufficient toner mixing state is obtained on a toner cartridge side without entrusting the agitation and mixture of the toners onto a developing apparatus side. 
     According to the invention, the used toner drops by gravity from the used toner recycling opening in the upper portion of the cartridge main body storing the fresh toner. Further, the toner agitating means and the toner supply means for supplying the mixed toner to the developing apparatus are arranged within the cartridge main body. Thus, the toner can be sufficiently mixed and agitated on the cartridge main body side without entrusting the mixture and the agitation onto the developing apparatus side. Further, it is possible to prevent an image forming apparatus from being large-sized. In particular, since the used toner drops by gravity, its taking-in structure is simplified, and the used toner can be efficiently mixed with the fresh toner irrespective of a moving direction of the toner agitating means. 
     In the invention it is preferable that the toner cartridge has a first film sealing member separably joined to the cartridge main body, for sealing the used toner recycling opening, and a second film sealing member separably joined to the cartridge main body, for sealing the toner supply opening, and each of free ends of the first and second film sealing members extending from their respective joining ends to an unsealing operation position by turning-up is set to an unsealing operation end, and the unsealing operation ends of the first and second film sealing members may be connected to each other either as an integral piece or by a connecting member. 
     According to the invention, the unsealing operation ends of the first and second film sealing members are connected to each other as described, for example, above. Accordingly, when an unsealing operation, which is an operation of pulling the connected operation ends to remove the sealing members, is performed once in replacement of the toner cartridge, both the sealing members are simultaneously separated from the cartridge main body, and the used toner recycling opening and the toner supply opening are reliably opened. Namely, with this structure it is prevented that only one of the opening portions is still in a sealing state. Further, it is sufficient to connect both the film sealing members at their unsealing operation ends after both the opening portions are sealed by the separate film sealing members at their sealing ends. Accordingly, the work of sealing the openings is easily made. 
     According to the invention, the toner cartridge has the first film sealing member separably joined to the cartridge main body and sealing the used toner recycling opening, and the second film sealing member separably joined to the cartridge main body and sealing the toner supply opening, and free ends of the first and second film sealing members extending from their respective joining ends to unsealing operation positions by turning-up are respectively set to unsealing operation ends, and these unsealing operation ends are connected to each other. Accordingly, when one unsealing operation using tensile force is performed, both the sealing members are simultaneously separated from the cartridge main body, and it is possible to dissolve a fear that one of the used toner recycling opening and the toner supply opening is used in error in a sealing state. Further, it is sufficient to connect both the film sealing members after both the opening portions are sealed by the separate film sealing members. Accordingly, the work of sealing the opening portions can be easily made. 
     In the invention it is preferable that the unsealing operation ends of the first and second film sealing members are integrally constructed for example, as a continuous piece. 
     According to the invention, the unsealing operation ends of the first and second film sealing members are integrally formed. Accordingly, it is not necessary to connect both the unsealing operation ends so that a manufacturing process can be simplified. 
     According to the invention, since the unsealing operation ends of both the first and second film sealing members are integrally formed, it is possible to omit the work of connecting the unsealing operation ends of both the film sealing members so that the manufacturing process can be simplified. 
     In the invention it is preferable that a contact portion is formed in a connecting portion of the unsealing operation ends of the first and second film sealing members which contact portion contacts with a portion of an outer covering member of an image forming apparatus provided with the developing apparatus, in a state where the cartridge main body is mounted to the developing apparatus to inhibit closure of the outer covering member. 
     According to the invention, in the mounting state of the cartridge main body to the developing apparatus, the contact portion formed in the connecting portion of the unsealing operation ends of the first and second film sealing members unseparated from the cartridge main body contacts with one portion of the outer covering member of the image forming apparatus, and cannot close the outer covering member. Accordingly, it is necessary to separate the first and second film sealing members from the cartridge main body and remove the contact portion to close the outer covering member and perform an image forming operation of the image forming apparatus. Thus, no image forming operation is executed in a sealing state of each of the used toner recycling opening and the toner supply opening. Further, no worker forgets the work of separating the first and second film sealing members from the cartridge main body. 
     According to the invention, in the mounting state of the cartridge main body to the developing apparatus, the contact portion formed in the connecting portion of the unsealing operation ends of the first and second film sealing members unseparated from the cartridge main body contact with one portion of the outer covering member of the image forming apparatus, and cannot close the outer covering member. Accordingly, it is possible to prevent the image forming operation from being executed in the sealing state of each of the used toner recycling opening and the toner supply opening. Further, it is possible to reliably prevent a worker from forgetting the work of removing the first and second film sealing members from the cartridge main body. 
     In the invention it is preferable that the cartridge main body has a winding rotating body for separating the first and second film sealing members from the cartridge main body by winding the unsealing operation ends of the first and second film sealing members. 
     According to the invention, when the winding rotating body is rotated, both the film sealing members are wound together so that the used toner recycling opening and the toner supply opening are easily unsealed. 
     According to the invention, the cartridge main body has the winding rotating body for winding the respective unsealing operation ends of both the film sealing members together. Accordingly, both the film sealing members can be wound around the winding rotating body together by rotating the winding rotating body. Therefore, it is possible to reduce an unsealing labor of the used toner recycling opening and the toner supply opening. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein: 
     FIG. 1A is a cross-sectional view of an image forming apparatus including a toner cartridge of a first embodiment of the invention; 
     FIG. 1B is a cross-sectional view of an image forming apparatus to which a toner cartridge of a second embodiment of the invention is applied; 
     FIG. 1C is a cross-sectional view of an image forming apparatus to which a toner cartridge of a third embodiment of the invention is applied; 
     FIG. 2 is a cross-sectional view of a sealing structure with respect to the opening portions of the toner cartridge of the first embodiment of the invention, in a state where the toner cartridge is mounted to the developing apparatus; 
     FIG. 3A is a perspective view showing arrangement of a part of an image forming apparatus to which a toner cartridge of the invention is mounted; 
     FIG. 3B is a view showing a physical relationship between a connecting part and an outer covering member; 
     FIG. 3C is a plan view with respect to the members in FIG. 3B; 
     FIG. 4 is a cross-sectional view showing another example of the sealing members; 
     FIG. 5 is a perspective view showing a used toner collecting structure of a conventional image forming apparatus; 
     FIG. 6 is a perspective view showing another used toner collecting structure in a conventional image forming apparatus; 
     FIG. 7 is a perspective view showing still another used toner collecting structure in a conventional image forming apparatus; 
     FIG. 8 is a cross-sectional view showing a toner cartridge having conventional collecting and mixing functions of used toner; and 
     FIG. 9 is a cross sectional view showing a toner cartridge having a conventional sealing member collecting mechanism. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Now referring to the drawings, preferred embodiments of the invention are described below. 
     FIG. 1A is a cross-sectional view of an image forming apparatus including a toner cartridge of a first embodiment of the invention. This image forming apparatus includes a toner cartridge  1 , a developing apparatus  2 , a photoconductor drum  3  and so on. The toner cartridge  1  is detachably mounted with a projecting portion  1   c  of the toner cartridge  1  being fitted to a joint  2 A formed on a side portion of the developing apparatus  2 . The toner cartridge  1  includes a cartridge main body  1 A, an agitating blade  12  and a toner replenishing roller  13 . 
     A charger  4 , an exposure device  5 , a developing roller  22  of the developing apparatus  2 , a transfer device (not shown) and a cleaner  6  are arranged in the order as mentioned, around the photoconductor drum  3  along its rotating direction. 
     A part of the surface of the photoconductor drum  3  is opposed to an opening face of the charger  4 , and the entire surface of the photoconductor drum  3  is uniformly charged by discharge from the charger  4 . The surface of the photoconductor drum  3  is subject to irradiation of light in accordance with printing information so that an electrostatic latent image is formed thereon in accordance with the applied electric charge pattern. 
     The developing apparatus  2  includes a developing portion housing  21 , the developing roller  22  arranged in a position opposed to the photoconductor drum  3 , a first agitating roller  23  and a second agitating roller  24 . Respective rotating shafts  23   a ,  24   a  of the agitating rollers  23 ,  24  are supported with respect to the developing portion housing  21 . 
     Toner supplied from the cartridge  1  and toner within the developing portion housing  21  are agitated by the first agitating roller  23 , and the agitated toner is further agitated by the second agitating roller  24 , and is then brought to the developing roller  22 . 
     The developing roller  22  is provided with a plurality of magnetizing portions  22   a  polarized alternatively in a circumferential direction thereof, and a developing sleeve  22   b  having a magnetization and disposed on an outer circumferential side of the magnetizing portions. A predetermined developing bias voltage is applied to the developing sleeve  22   b , and the developing sleeve  22   b  holds toner and carrier charged to polarities opposite to each other in an outer circumferential portion. The electrostatic latent image formed on the surface of the photoconductor drum  3  is developed with the toner brought thereon during contact with the developing roller  22  of the developing apparatus  2  as the roller rotates, and is visualized as a toner image. Next, the toner image formed on the photoconductor drum  3  is transferred to a surface of a transfer material by the transfer device (not shown), and is then fixed on the surface of the transfer material with a fixing device such as a heat roller. The cleaner  6  sweeps off the used toner t left on the surface of the photoconductor drum  3  with a blade  6   a  formed of urethane resin or the like, after the transfer process. 
     Between the cleaner  6  and the cartridge main body  1 A, a toner collecting duct  7  is provided. The used toner t removed by the cleaner  6  is collected to the toner collecting duct  7 , through which the used toner t is brought to the side of the cartridge main body  1 A by a rotatable conveying blade provided therein. 
     The cartridge main body  1 A stores fresh toner T and the used toner t, and includes a top wall portion  1   a , the projecting portion  1   c , a developing apparatus side wall portion  1   e , an opposite side wall portion  1   f , a bottom wall portion  1   g  and a pair of side wall portions  1   h ,  1   i . The top wall portion  1   a  is placed as a top portion of the cartridge main body  1 A. The developing apparatus side wall portion  1   e  is placed on the side closer to the developing apparatus  2  as a lower portion of the cartridge main body  1 A. 
     The projecting portion  1   c  is located near the upper portion of the cartridge main body  1 A, and includes a wall portion  1   b  and a projecting side wall portion  1   d . The wall portion  1   b  is projected outward from the developing apparatus side wall portion  1   e . The projecting side wall portion  1   d  is arranged between the edges of the top wall portion  1   a  and the wall portion  1   b . As shown in FIG. 1A, the projecting portion  1   c  is projected outward from the developing apparatus side wall portion  1   e , and is fitted and supported to the joint  2 A of the developing apparatus  2 . 
     The opposite side wall portion  1   f  is placed opposite to the projecting side wall portion  1   d  and the developing apparatus side wall portion  1   e . The bottom wall portion  1   g  extends to the developing apparatus side wall portion  1   e  and the opposite side wall portion  1   f , defining a bottom portion of the cartridge main body  1 A. The pair of side wall portions  1   h ,  1   i  are placed to connect the edges of the respective side wall portions  1   b ,  1   d  to  1   g  (edges are located in a direction perpendicular to a paper face on FIG.  1 A). The top wall portion  1   a  is provided to connect the upper portions of the side wall portions  1   d ,  1   f ,  1   h ,  1   i . Thus, an internal space of the cartridge main body  1 A is defined by these respective wall portions  1   a ,  1   b ,  1   d  to  1   i.    
     A used toner recycling opening  11  is formed in the upper wall  1   a  of the cartridge main body  1 A in order to let the used toner t pass through from the toner collecting duct  7  towards the cartridge main body  1 A by gravity. Further, a toner supply opening  14  is formed in the wall portion  1   b  of the projecting portion  1   c  in accordance with the location of a toner receiving hole  25  on a side of the developing apparatus  2 . The toner supply opening  14  is formed as a long slit shape extending along the axial direction of the toner replenishing roller  13  described later. 
     The agitating blade  12  is located inside the cartridge main body  1 A approximately at its center, and is provided as agitating means for agitating and mixing the fresh toner T and the used toner t. The agitating blade  12  is provided with a flexible scoop piece  12   a , extending in a direction opposite to a rotating direction (a direction opposite to an arrow in FIG. 1A) of the agitating blade  12 . The flexible scoop piece  12   a  scoops up the fresh toner T being agitated towards a toner replenishing roller  13  described below. A toner replenishing means, for example the toner replenishing roller  13 , is provided within the cartridge main body  1 A. A rotating shaft  13   a  of this toner replenishing roller  13  is rotatably supported by side wall portions  1   h ,  1   i  of the cartridge main body  1 A. The toner replenishing roller  13  is formed of a porous elastic body such as a urethane sponge so that the toner replenishing roller  13  can be rotated in close contact with an inner face of the cartridge main body  1 A. 
     The toner replenishing roller  13  drops mixed toner of fresh toner T and used toner t towards the position close to the first agitating roller  23  through the toner supply opening  14  when the toner replenishing roller  13  receives a toner replenishing signal generated in accordance with a toner density detecting signal from a toner sensor (not shown) provided inside the developing apparatus  2 . 
     When the toner cartridge  1  is used, the used toner t falls into the cartridge main body  1 A by gravity through the used toner recycling opening  11 , and is agitated and mixed with the fresh toner T by the agitating blade  12 . The agitated and mixed toners T, t are scooped upward by rotation movement of the scoop piece  12   a  of the agitating blade  12  to the position of the toner replenishing roller  13 . Then, the mixed toner is replenished from the toner supply opening  14  to the developing apparatus  2  as the toner replenishing roller  13  rotates. 
     The physical relationship between the toner replenishing roller  13  and the used toner recycling opening  11  may be set as desired, and the toner replenishing roller  13  may also be positioned near the used toner recycling opening  11 . In this case, it is also possible to mix the used toner t dropping by gravity with the fresh toner T scooped up at the toner replenishing roller  13 . 
     Further, the fresh toner T and the used toner t are mixed together inside the cartridge main body  1 A and then supplied to the developing apparatus  2 . Accordingly, the fresh toner T and the used toner t are well-mixed compared to the case where the mixing and agitation operations of the fresh toner T and the used toner t are performed at the developing apparatus  2 . Therefore, burden on the developing apparatus  2  can be reduced, and a stable image quality can be obtained. 
     The agitating blade  12  as a mixing portion for mixing and agitating the used toner t and the fresh toner T, and the toner replenishing roller  13  as a toner supply portion are arranged inside the cartridge main body  1 A. Accordingly, the toner cartridge is easily made compact in comparison with the case where the mixing portion is mounted outside the cartridge main body  1 A. 
     In particular, the used toner recycling opening  11  is formed in the upper wall  1   a  of the cartridge main body  1 A, and the used toner t is dropped by gravity. Accordingly, it is possible to perform preferable agitating and mixing operations irrespective of a rotating direction of the agitating blade  12 . Further, a taking-in mechanism and special blocking structure which performs forced conveying of the used toner t from a lower side of the cartridge main body  1 A to the interior, are not required, thereby making a simplified structure possible. 
     FIG. 1B is a cross-sectional view of an image forming apparatus to which a toner cartridge of a second embodiment of the invention is applied. In the second embodiment, parts corresponding to those in the first embodiment are given the same reference numerals, accordingly repetition of the same explanation is avoided. The toner cartridge  51  shown in FIG. 1B has a construction similar to the toner cartridge  1  shown in FIG.  1 A. However, in the second embodiment, the used toner t is brought to a toner cartridge main body  51 A through an opening provided to an upper side portion of the closer side to the developing apparatus  2  of the toner cartridge  51 . 
     The toner cartridge  51  includes the toner cartridge main body  51 A, an agitating blade  12  and a toner replenishing roller  13 . The toner cartridge main body  51 A stores the fresh toner T and the used toner t, and includes a wall portion  51   b , a projecting portion  51   c , a projecting side wall portion  51   d , a developing apparatus side wall portion  51   e , an opposite side wall portion  51   f , a bottom wall portion  51   g  and a pair of side wall portions  51   h ,  51   i  which are respectively similar in construction to the wall portion  1   b , the projecting portion  1   c  the projecting side wall portion  1   d , the developing apparatus side wall portion  1   e , the opposite side wall portion  1   f , the bottom wall portion  1   g  and the pair of side wall portions  1   h ,  1   i  in the toner cartridge  1 . Further, the toner cartridge main body  51 A includes a first top wall portion  51   a , a second top wall portion  51   j  and an upper side wall portion  51   k  in an upper portion of the toner cartridge main body  51 A. The wall portions  51   a ,  51   j ,  51   k  close upper portions of the respective side wall portions  51   d ,  51   f ,  51   h ,  51   i.    
     The first top wall portion  51   a  is placed in an area of the upper portion of the toner cartridge main body  51 A on a side closer to the developing apparatus  2 . The second top wall portion  51   j  is placed in a relatively outward position from a position of the first top wall portion  51   a  and an area of an upper portion of the toner cartridge main body  51 A on a side farther from the developing apparatus  2  compared to the first top wall portion  51   a . The upper side wall portion  51   k  is placed between the first top wall portion  51   a  and the second top wall portion  51   j  so as to bypass an edge of the first top wall portion  51   a  on a side farther from the developing apparatus  2  and an edge of the second top wall portion  51   j  on a side closer to the developing apparatus  2 . 
     A used toner recycling opening  52  for dropping the used toner t by gravity from the toner collecting duct  7  into the cartridge main body  51 A is formed in the upper side wall portion  51   k . Similar to the toner cartridge  1  in the first embodiment, an agitating blade  12  and a toner replenishing roller  13  are provided inside the cartridge main body  51 A. 
     Effects similar to those in the second embodiment are also obtained in such a construction. 
     FIG. 1C is a cross-sectional view of an image forming apparatus to which a toner cartridge of a third embodiment of the invention is applied. In the third embodiment, parts corresponding to those in the above embodiments are given the same reference numerals, where repetition of the same explanation is avoided. The toner cartridge  61  shown in FIG. 1C has a construction similar to the toner cartridges  1 ,  51  shown in FIGS. 1A and 1B, and it should be noticed that the used toner t is supplied into a toner cartridge main body  61 A from a side opposed to a side of the developing apparatus  2  on an upper portion side of the toner cartridge  61 . 
     The toner cartridge  61  includes the toner cartridge main body  61 A, an agitating blade  12  and a toner replenishing roller  13 . The toner cartridge main body  61 A stores the fresh toner T and the used toner t, and includes a wall portion  61   b , a projecting portion  61   c  a projecting side wall portion  61   d , a developing apparatus side wall portion  61   e , an opposite side wall portion  61   f , a bottom wall portion  61   g  and a pair of side wall portions  61   h ,  61   i  which are respectively similar in construction to the wall portions  1   b ; 51   b ,the projecting portion  1   c ; 51   c  the projecting side wall portions  1   d ; 51   d , the developing apparatus side wall portions  1   e ; 51   e , the opposite side wall portions  1   f ; 51   f , the bottom wall portions  1   g ; 51   g , and the pair of side wall portions  1   h ,  1   i ; 51   h ,  51   i  in the toner cartridges  1 ; 51 . Further, the toner cartridge main body  61 A includes a top wall portion  61   a  for closing upper portions of the respective side wall portions  61   d ,  61   f ,  61   h ,  61   i.    
     A used toner recycling opening  62  for dropping the used toner t by gravity from the toner collecting duct  7  into the cartridge main body  61 A is formed in an upper portion of the opposite side wall portion  61   f  opposed to the projecting side wall portion  61   d  and the developing apparatus side wall portion  61   e . Similar to the toner cartridges  1 ,  51  in the first and second embodiments, the agitating blade  12  and the toner replenishing roller  13  are provided inside the cartridge main body  61 A. 
     Effects similar to those in the first and second embodiments are also obtained in such a construction. 
     In addition, the used toner recycling opening  62  is provided at a position considerably distant from the toner supply opening  14 , and thus the used toner t is not carried to the developing apparatus  2  through the toner supply opening  14  before being well-mixed with the fresh toner T. In this manner, a premature supply of the used toner t to the developing apparatus  2  is prevented. 
     FIG. 2 is a cross-sectional view of a sealing structure with respect to the openings  11 ,  14  of the toner cartridge  1  of the first embodiment of the invention in a state where the toner cartridge  1  is mounted to the developing apparatus  2 . In FIG. 2, a film first sealing member  31  is removably attached to the cartridge main body  1 A so as to seal the used toner recycling opening  11 . A second film sealing member  32  is removably attached to the cartridge main body  1 A so as to seal the toner supply opening  14 . 
     One end  31   a  of the film first sealing member  31 , which serves as a sealing end, is removably attached around the used toner recycling opening  11  on the outer surface of the cartridge main body  1 A by means of heat melting attachment or an adhesive or the like. The film first sealing member  31  is turned around for 180° at a turning position  31   c  such that the other end  31   b  as an unsealing operation end, which is defined as an operation end in removing the first sealing member  31  from the cartridge main body  1 A by pulling, is placed in an unsealing operation position with respect to the cartridge main body  1 A. 
     Similarly, one end  32   a  of the second film sealing member  32 , which serves as a sealing end, is removably attached around the toner supply opening  14  on the outer surface of the portion  1   b  of the cartridge main body  1 A by means of heat melting attachment or an adhesive or the like. The second film sealing member  32  is turned around for 180° at turning position  32   c  in a direction parallel to a rotating shaft  13   a  of the toner replenishing roller  13 , such that the other end  32   b  as an unsealing operation end, which is defined as an operation end in removing the second sealing member  32  from the cartridge main body  1 A by pulling, is placed in the unsealing operation position on the side of the cartridge main body  1 A. The unsealing operation ends  31   b ,  32   b  of both the film sealing members  31 ,  32  may be directly connected to each other or via a connecting member  33  as shown in the embodiment. 
     When the toner cartridge  1  is used in such a construction, the toner cartridge  1  is joined to the developing apparatus  2  at a predetermined portion. In this state, the unsealing operation is performed by pulling the connecting member  33  for connecting the respective unsealing operation ends  31   b ,  32   b  of the film sealing members  31 ,  32  in a direction of an arrow A of FIG. 2, so that the respective sealing ends  31   a ,  32   a  of the film sealing members  31 ,  32  are removed from the attached position on the outer surface of the cartridge main body  1 A, and the used toner recycling opening  11  and the toner supply opening  14  are opened. 
     FIG. 3A is a perspective view showing arrangement of a part of the image forming apparatus, FIG. 3B is a view showing a physical relationship between a connecting part and an outer covering member, and FIG. 3C is a plan view with respect to the members in FIG.  3 B. The connecting member  33  includes a connecting portion  33   a  for connecting the respective sealing ends  31   a ,  32   a  of the film sealing members  31 ,  32  and the connecting member  33  projected from the connecting portion  33   a  toward an outer covering member  70  of the image forming apparatus on the operation side thereof. That is, the outer covering member  70  of the image forming apparatus on its operation side is provided so as to be freely opened and closed. In order to mount the cartridge main body  1 A to the developing apparatus  2 , the outer covering member  70  of the image forming apparatus on its operation side is opened, and then the developing apparatus  2  is exposed to the operation side of the image forming apparatus as shown in FIG.  3 A. Thereafter, the cartridge main body  1 A is mounted to the developing apparatus  2 , and the film sealing members  31 ,  32  are unsealed to remove. Thereby, the outer covering member  70  can be placed at the closed position P 1  as shown in FIGS. 3B and 3C. Thereafter, the image forming apparatus becomes a state where an image forming operation can be performed when the outer covering member  70  on the operation side is closed. In the case where the outer covering member  70  of the image forming apparatus on its operation side is attempted to close without removing the film sealing members  31 ,  32  from the cartridge main body  1 A mounted to the developing apparatus  2 , the contact portion  33   b  of the connecting member  33  comes into contact with a part of the outer covering member  70  as shown in FIGS. 3B and 3C, whereby the outer covering member  70  is placed at the position P 2  in order not to be closed. 
     When the toner cartridge  1  is used in a state where the used toner recycling opening  11  is sealed, there will be a possibility of problems such that the used toner t from the cleaner  6  is clogged within the collecting duct  7 , resulting in malfunction of replenishing operation. Further, when the toner cartridge  1  is used in a state where the toner supply opening.  14  is sealed, toner will not be adequately supplied even if toner density within the developing apparatus  2  is in decline. Accordingly, there will be such a problem that no image can be formed. 
     On the other hand, in the case where the film sealing members  31 ,  32  are directly connected to each other at the respective unsealing operation ends  31   b ,  32   b  as mentioned above, and are not separated and removed in the toner cartridge  1  mounted to the developing apparatus  2 , the contact portion  33   b  of the connecting member  33  comes into contact with one portion of the outer covering member  70 , whereby the outer covering member  70  cannot be tightly closed. Therefore, the outer covering member  70  on the operation side of the image forming apparatus cannot be closed unless the film sealing members  31 ,  32  are removed together with the connecting member  33  from the cartridge main body  1 A mounted to the developing apparatus  2 . Accordingly, no image forming operation can be started in this state. Thus, it is possible to reliably prevent a user from operating without removing the film sealing members  31 ,  32  from the cartridge main body  1 A. Accordingly, when an image forming operation is started, the used toner recycling opening  11  and the toner supply opening  14  can reliably be opened. Therefore, there will not be such a problem that malfunction of replenishing operation of the used toner t or absence of a formed image occurs. 
     The film sealing members  31 ,  32  are provided with the turning positions  31   c ,  32   c  respectively. As such, when both of the unsealing operation ends  31   b ,  32   b  are pulled out in the direction of the arrow A, outward separating force on the basis of tensile force is applied to the sealing ends  31   a ,  32   a  so that the sealing ends  31   a ,  32   a  can easily be removed. 
     Further, in the case where sealing processes on the used toner recycling opening  11  and the toner supply opening  14  are performed before a connecting process with respect to the unsealing operation ends  31   b ,  32   b  of both the film sealing members  31 ,  32 , both of the film sealing members  31 ,  32  will not be entangled during the sealing process for the openings  11 ,  14 , thereby realizing an efficient production process. 
     Further, the unsealing operation ends  31   b ,  32   b  of both the film sealing members  31 ,  32  may be continuously formed as a single sealing member. In this case, a process of connecting both the unsealing operation ends  31   b ,  32   b  after sealing can be omitted. 
     FIG. 4 shows a spool  41  for winding the respective unsealing operation ends  31   b ,  32   b  of the film sealing members  31 ,  32 , being rotatably supported at a predetermined position of the cartridge main body  1 A, such as in a bracket  42  projected on a side face of the cartridge main body  1 A. 
     In this construction, both the film sealing members  31 ,  32  are wound around the spool  41  arranged outside the cartridge main body  1 A by rotating the spool  41  by a handle  43  or the like. Accordingly, the unsealing operation by means of removing the film sealing members  31 ,  32  can easily be made. Therefore, it is possible to prevent the sealing members  31 ,  32  from causing a negative impact on toner mixing or conveying performance inside the toner cartridge  1 . 
     The sealing member positions shown in FIG.  2  and the winding construction of the sealing members shown in FIG. 4 can also be applied to the toner cartridges  51 A,  61 A shown in FIGS. 1B and 1C. Similar effects using these constructions are obtained. 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and the range of equivalency of the claims are therefore intended to be embraced therein.