Abstract:
An image forming member includes: an electrostatic latent image holding member that holds an electrostatic latent image; a developing unit that develops a toner image formed by a toner on a surface of the electrostatic latent image holding member; a toner removing member that removes a residual toner remaining on a surface of the electrostatic latent image holding member; a conveying path including a conveying member that is internally provided in the conveying path and that returns the residual toner removed from the surface of the electrostatic latent image holding member to the developing unit; and a trapping portion that traps a foreign matter conveyed by the conveying member, the electrostatic latent image holding member, the developing unit, the toner removing member, the conveying path, and the trapping portion of the image forming member being integrally and detachably attached to an image forming apparatus body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based on and claims priority under 35 U.S.C. 119 from Japanese Patent Application No. 2006-236698 filed Aug. 31, 2006. 
   BACKGROUND 
   1. Technical Field 
   The present invention relates to an image forming member, to a toner removing apparatus, to a developing apparatus, and to an image forming apparatus. 
   2. Related Art 
   There is an art such as a recycled developer classification apparatus that collects, after performing an image forming process, residual developers, that classifies the collected developers into those to be reused, and those to be discarded, and that has a classification portion including filter means which classifies the collected developers into those to be reused, and those to be discarded. 
   The classification apparatus serves as a filtering means configured so that a cylindrical mesh of a toner classification unit fitted into a pipe communicating with a path used to convey toner, which is not transferred to transfer paper, to the toner classification unit is rotationally driven to rotate thereby to separate foreign matters from developers. 
   There is an art such as an electrophotographic apparatus which comprises a developing unit configured to accommodate a two-component developer including toner and carrier and to develop an electrostatic latent image with a developer, and also comprises a toner recycling mechanism to thereby form images and recycle the toner. The developing unit of this electrophotographic apparatus has a mesh member provided in a developer flow path, and also has a rubbing member configured to rub against the mesh member. Thus, paper powder in recycled toner is positively rubbed against the mesh member to thereby crush the paper powder into small particles. Simultaneously, the meshes of the mesh member are prevented from being clogged. 
   SUMMARY 
   According to an aspect of the present invention, an image forming member comprising: an electrostatic latent image holding member that holds an electrostatic latent image; a developing unit that develops a toner image formed by a toner on a surface of the electrostatic latent image holding member; a toner removing member that removes a residual toner remaining on a surface of the electrostatic latent image holding member; a conveying path including a conveying member that is internally provided in the conveying path and that returns the residual toner removed from the surface of the electrostatic latent image holding member to the developing unit; and a trapping portion that traps a foreign matter conveyed by the conveying member, the electrostatic latent image holding member, the developing unit, the toner removing member, the conveying path, and the trapping portion of the image forming member being integrally and detachably attached to an image forming apparatus body. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
       FIG. 1A  is an explanatory view illustrating an outline of a mode for implementing an image forming apparatus according to the invention.  FIG. 1B  is a cross-sectional view taken along line B-B shown in  FIG. 1A ; 
       FIG. 2  is an explanatory view illustrating the entire configuration of a first embodiment of the image forming apparatus to which the invention is applied; 
       FIG. 3  is an explanatory view illustrating an outline of a process cartridge used in the first embodiment, which is taken from the front of the apparatus; 
       FIG. 4  is an explanatory view illustrating an outline of a process cartridge used in the first embodiment, which is taken from the rear of the apparatus; 
       FIG. 5  is a view taken in the direction of an arrow V shown in  FIG. 4 ; 
       FIG. 6  is an explanatory cross-sectional view taken along line VI-VI shown in  FIG. 5 ; 
       FIG. 7A  is a cross-sectional view taken along line VII-VII shown in  FIG. 3 .  FIG. 7B  is a cross-sectional view taken along line B-B shown in  FIG. 7A ; 
       FIG. 8  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in the first embodiment; 
       FIG. 9A  is an explanatory view illustrating an outline of a trapping member used in the first embodiment.  FIG. 9B  is an explanatory view illustrating a state in which a trapping sheet is attached; 
       FIG. 10  is an explanatory view illustrating a toner return mechanism used in the first embodiment in detail; 
       FIG. 11  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a second embodiment; 
       FIG. 12A  is an explanatory view illustrating a trapping member used in the second embodiment.  FIG. 12B  is an explanatory view illustrating a state in which the trapping member is attached; 
       FIG. 13A  is an explanatory view illustrating a modification of the trapping member used in the second embodiment.  FIG. 13B  is an explanatory view illustrating a state in which the trapping member shown in  FIG. 13A  is attached; 
       FIG. 14  is an explanatory view illustrating a collected toner conveying member of a toner removing unit used in a third embodiment; 
       FIG. 15  is an explanatory view illustrating a collected toner conveying member of a toner removing unit used in a fourth embodiment and also illustrating the configuration of the periphery of this collected toner conveying member; 
       FIG. 16  is an explanatory view illustrating a collected toner conveying member of a toner removing unit used in a fifth embodiment and also illustrating the configuration of the periphery of this collected toner conveying member; 
       FIG. 17A  is an explanatory view illustrating a collected toner conveying member of a toner removing unit used in a sixth embodiment and also illustrating the configuration of the periphery of this collected toner conveying member.  FIG. 17B  is an explanatory view illustrating a manufacturing method for a trapping member shown in  FIG. 17A ; 
       FIG. 18A  is an explanatory view illustrating a collected toner conveying member of a toner removing unit used in a seventh embodiment and also illustrating the configuration of the periphery of this collected toner conveying member.  FIG. 18B  is an explanatory view detailedly illustrating a trapping member shown in  FIG. 18A ; 
       FIG. 19A  is an explanatory view illustrating a primary part of the configuration of a developing unit used in an eighth embodiment.  FIG. 19B  is an explanatory view detailedly illustrating a trapping member used in the developing unit shown in  FIG. 19A ; and 
       FIG. 20A  is an explanatory view illustrating a primary part of the configuration of a developing unit used in a ninth embodiment.  FIG. 20B  is an explanatory view detailedly illustrating a trapping member used in the developing unit shown in  FIG. 20A . 
   

   DETAILED DESCRIPTION 
   First, an outline of an embodiment model, to which the invention is applied, is described below. 
   Outline of Embodiment Model 
     FIG. 1A  is an explanatory view schematically an image forming apparatus according to an embodiment model implementing the invention.  FIG. 1B  is an explanatory cross-sectional view taken on line B-B shown in  FIG. 1A . 
   The image forming apparatus shown in these figures visualizes an electrostatic latent image, using toner. The image forming apparatus includes an electrostatic latent image holding member  1 , for example, a photoreceptor drum capable of holding an electrostatic latent image, and also includes a developing unit  2  that has a developing member  2   a , for example, a magnetic roll facing the electrostatic latent image holding member  1  and that uses toner supplied to the developing member  2   a  to visualize an electrostatic latent image. The image forming apparatus also includes a toner removing unit  3  that has a toner removing member  3   a , for example, a cleaning blade adapted to remove toner remaining on the electrostatic latent image holding member  1 , and that collects toner removed by the toner removing member  3   a , and a conveying path  4  used to return the toner collected by the toner removing unit  3  to the developing unit  2 . 
   In this embodiment model, a rotary conveying member having a rotating shaft and a spiral blade formed around the rotating shaft, which is an example of a conveying member  5  for conveying toner, is disposed in all or a part of the conveying path  4 . A trapping portion  8  configured to trap a foreign matter by simultaneously suppressing the foreign matter from moving in a toner conveying direction, in which toner is conveyed by the conveying member  5 , and also simultaneously allowing the toner to pass therethrough, is provided between the conveying member  5  and the conveying path  4 . 
   In such a technical means, the developing method employed by the developing unit  2  includes not only a two-component developing method but a single-component developing method. The layout of the developing unit  2  and the toner removing unit  3  is optional. However, from the viewpoint of returning toner to an upper position and then effectively utilizing the free fall of the toner due to the force of gravity, preferably, the toner removing unit  3  is disposed above the developing unit  2 . It is optional to provide the conveying path  4 , through which toner is conveyed between the toner removing unit  3  and the developing unit  2 , and to also provide the conveying member  5 , which conveys toner, in the conveying path  4 . Although a path simply utilizing the free fall due to the force of gravity may be employed as the conveying path  4  between the toner removing unit  3  and the developing unit  2 , preferably, the conveying member  5  is provided in a mode, in which the conveying path  4  has, for example, a first component, to assure toner conveyability. For instance, a conveying member having a plate-like blade is used as an example of such a kind of the conveying member  5 . 
   Additionally, the electrostatic latent image holding member  1 , the developing unit  2 , the toner removing unit  3 , and the conveying path  4  between the developing unit  2  and the toner removing unit  3  may be separated from and independent of one another. However, in consideration of the replacement workability of components and a toner spill in an image forming apparatus, the present embodiment model employs a process cartridge integrally including these elements. In consideration of the maintenance of the members, the exchange time thereof, the cleaning of foreign matters trapped by the trapping member, and the replacement of the trapping member, the process cartridge may be set in a mode in which the process cartridge can be divided into the members after detached from the image forming apparatus. Alternatively, the process cartridge may be set in a mode in which both of the detachment of each of the members and the integral detachment of the members are possible. 
   A rotary conveying member having a rotating shaft and a spiral blade formed therearound and a conveying member equipped with a plate-like-blade are described in the description of the present embodiment model as the conveying member  5 . However, the conveying member according to the invention is not limited thereto. As long as conveying toner in a predetermined direction, any conveying member may be included. For example, a conveying member may be employed, which conveys toner by forming and rotating spiral wire-like members around a rotating shaft. 
   It is sufficient that the trapping portion  8  traps foreign matters, for example, fibrous dusts between the inner wall surface of the conveying path  4  and the conveying member  5  provided in the conveying path  4 . For example, it is sufficient that the trapping portion  8  suppresses foreign matters from moving in a direction in which toner is conveyed by the conveying member  5 . 
   In the description of the present embodiment model, the trapping portion  8 , which extends from the inner wall surface of the conveying path  4  toward the conveying member  5  and is formed of a flexible member, is described as an example. However, the trapping portion according to the invention is not limited thereto. A trapping member extending from the conveying member  5  to the inner wall surface of the conveying path  4  may be used. In a case where the conveying member  5  has a rotating shaft and a conveying portion disposed around the rotating shaft, the trapping portion  8  may be provided either on the rotating shaft or in the conveying portion. Additionally, foreign matters may be trapped by providing the trapping portion either on the rotating shaft or in the conveying portion. 
   Additionally, the trapping portion  8  may be disposed at a place, at which the conveying member  5  is disposed, in the conveying path  4  which may be any of that  4  provided in the toner removing unit  3 , that  4  provided in the developing unit  2 , and that  4  provided between the toner removing unit  3  and the developing unit  2 . Alternatively, the trapping portion  8  may be provided at each of a plurality of components. 
   Regarding the relation between the trapping portion  8  and the conveying member  5 , the trapping portion  8  may be disposed to be either contacted with the conveying member  5  or not contacted with the conveying member  5 . 
   Concerning a structure into which the trapping portion  8  is incorporated, a trapping member having the trapping portion  8  may be attached to an inner wall surface of the conveying path  4 . Alternatively, a trapping member having the trapping portion  8  may be attached to the side of the conveying member  5 . Alternatively, the trapping portion  8  may be formed integrally with all or a part of the conveying member  5 . 
   Additionally, it is sufficient to place the trapping portion  8  at least at one place. However, from the viewpoint of enhancing the ability to trap foreign matters, preferably, the trapping portions  8  are disposed at a plurality of places along the conveying path  4  in a toner conveying direction. 
   A preferable layout of the trapping portion  8  and the conveying member  5  is such that the conveying member  5  rotatably extends in the toner conveying direction and is disposed to penetrate through the trapping portion  8 . 
   It is important to ensure the ability to trap foreign matters by simultaneously circumventing the interference between the contact type trapping portion  8  and the conveying member  5 . A preferred example of the configuration of the contact type trapping portion  8  is such that the trapping portion  8  is fixed to the outside of the conveying member  5  and is disposed to be contacted with the conveying member  5 , and that at least a part of the trapping portion  8  is contacted with the conveying member  5  and includes an elastically deformable resilient member. 
   On the other hand, an example of the configuration of the non-contact type trapping portion  8  is such that the non-contact type trapping portion  8  is disposed in a space region provided above the conveying member  5  in the conveying path  4  so as to trap floating foreign matters. 
   Another example of the trapping portion  8  has a hook part at which a foreign matter conveyed by the conveying member  5  is hooked. Examples of the configuration of such a trapping portion  8  are such that the trapping portion is suspended from an upper part of a path partitioning member of the conveying path  4  and has a hook part at an end thereof, and that the trapping portion provided in the conveying member  5  has a hook part. 
   Hereinafter, the invention is described in more detail with reference to embodiments shown in the accompanying drawings. 
   First Embodiment 
     FIG. 2  illustrates the entire configuration of a first embodiment of an image forming apparatus to which the invention is applied.  FIG. 2  is a view illustrating the inside of the apparatus, which is taken from the front side (or near side). 
   (Entire Configuration of Image Forming Apparatus) 
   As shown in  FIG. 2 , the image forming apparatus is configured so that for example, an electrographic image forming engine  21  is mounted in an apparatus housing  20 , that a predetermined number (for example, 4) of supply trays  22  ( 22   a  to  22   d ) capable of supplying sheets of paper as recording media are disposed below the image forming engine  21  in the apparatus housing  20 . A discharge tray  27  capable of accommodating sheets of recorded paper is provided at the top portion of the apparatus housing  20 . A paper conveying path  23  adapted to guide sheets of paper S sent from each of the supply trays  22  to the image forming engine  21  and the discharge tray  27  is provided at a side surface side (the left side, as viewed in  FIG. 2 ) in the apparatus housing  20  to extend substantially vertically. 
   According to the present embodiment, the image forming engine  21  includes a photoreceptor drum  31  capable of holding an electrostatic latent image, an electrification unit  32 , for example, an electrification roll, configured to perform electrification of the photoreceptor drum  31 , an exposure unit  33 , for example, a laser scanning unit configured to write the electrostatic latent image formed on the photoreceptor drum  31 , a developing unit  34  configured to perform the toner development of the electrostatic latent image formed on the photoreceptor drum  31 , a transfer unit  35  using, for example, a transfer roll configured to transfer the electrostatic latent image formed on the photoreceptor drum  31  onto a sheet of paper S, and a toner removing unit  36  configured to remove residual toner remaining on the photoreceptor drum  31 . 
   Incidentally, in the present embodiment, the developing unit  34  employs the two-component developing method. Toner can be supplied from a toner box  37 , which accommodates a supplement toner, thereto through a supply path  38 . 
   A positioning roll  24  configured to position and convey a sheet of paper S is provided at the upstream side of the photoreceptor drum  31  in the paper conveying path  23 . A fixing unit  25  is disposed at the downstream side of the photoreceptor drum  31  in the paper conveying path  23 . A discharge roll  26  is provided just in front of the discharge tray  27 . 
   According to the present embodiment, a two-sided printing unit  28  enabled to perform two-sided printing on a sheet of paper is provided in the apparatus housing  20 . 
   According to the present embodiment, the image forming engine  21  serving as an example of an image forming member is configured so that a process cartridge is formed by integrating the photoreceptor drum  31 , the electrification unit  32 , the developing unit  34 , and the toner removing unit  36  as shown in  FIGS. 3 to 5 . 
     FIG. 3  illustrates a primary part of the process cartridge  30  shown in  FIG. 2 .  FIG. 4  is a perspective view of the process cartridge  30 , which is taken from the rear side thereof.  FIG. 5  is a view of the process cartridge  30  taken in the direction of an arrow V shown in  FIG. 4 . 
   Especially, according to the present embodiment, the process cartridge  30  reuses toner by returning toner, which is collected by the toner removing unit  36 , to the developing unit  34 . As shown in  FIGS. 4 and 5 , the conveying path is provided between the toner removing unit  36  and the developing unit  34 . 
   (Developing Unit) 
   As shown in  FIGS. 3 to 6 , the developing unit  34  is provided below the toner removing unit  36 . The developing unit  34  includes a developer accommodating container  41  which accommodates a two-component developer including toner and carrier and which is opened at the side of the photoreceptor drum  31 . A developing roll  42  is rotatably disposed at a part facing the opening formed in the developer accommodating container  41 . Paired agitation conveying members  43  and  44  are disposed along the direction of an axis of the developing roll  42  in the developer accommodating container  41 . A partitioning plate  45  is provided between the paired agitation conveying members  43  and  44 . Each of communication holes  46  and  47  is provided in the vicinity of an associated one of both ends in the longitudinal direction of the partitioning plate  45 . Thus, a developer circulation path  48 , in which the circulation conveyance of the developer can be performed, is constituted. Incidentally, reference numeral  49  is a layer regulating member adapted to regulate a developer layer formed on the developing roll  42 . 
   The agitation conveying member  43  placed at the side of the developing roll  42  functions mainly as a supply member used to supply the developer from the developing roll  42 . On the other hand, the agitation conveying member  44  provided at a far side from the developing roll  42  functions mainly as an agitation member used to agitate the developer. A driving force is transmitted from a drive motor (not shown) to the agitation conveying members  43  and  44  through a driving force transmitting mechanism (not shown) including gear trains. 
   A toner supply port  39  is opened in the vicinity of the upstream end of the agitation conveying member  44  in the developer accommodating container  41 . A supply path  38  connected to the toner box  37  is connected to the toner supply port  39 . A reuse toner supply port  50  is opened in the vicinity of the downstream end of the agitation conveying member  43  in the developer accommodating container  41 . 
   (Toner Removing Unit) 
   As shown in  FIGS. 3 ,  4 ,  7 A and  7 B, the toner removing unit  36  has a case  51  that is provided at a place located in an obliquely upward direction of the photoreceptor  31  and that is opened at the side of the photoreceptor drum  31 . A blade  52  serving as a cleaning member for removing the residual toner, which abuts against the photoreceptor drum  31 , is provided at an opening edge of the case  51 . A collected toner conveying member  53  adapted to rotate to collect the toner removed by the blade  52  toward an end in the longitudinal direction of the case  51  is also disposed in the case  51 . 
   The collected toner conveying member  53  has a spiral blade member  55  provided around a rotating shaft  54  for conveying the collected toner, as shown in  FIGS. 7A and 7B . An upstream end part of the rotating shaft  54  for conveying the collected toner is rotatably supported on an end wall of the case  51  through a bearing  56 . A downstream end part of the rotating shaft  54  for conveying the collected toner is disposed to rotatably penetrate through, for example, a circular collected toner discharge port  57  formed in the other end wall of the case  51 . A support portion  58  adapted to support a conveying member  91  is provided at a place which is eccentric from the center of rotation. 
   A drive system for the collected toner conveying member  53  is configured so that a driving force transmitting gear  61  is securely fixed to the upstream end part of the rotating shaft  54  for conveying the collected toner, and that, for example, a drive gear  62  of the photoreceptor drum  31  is meshed with the driving force transmitting gear  61 , and that a driving force outputted from a drive motor (not shown) is transmitted to the drive gear  62  and the driving force transmitting gear  61  through, for example, a driving force transmitting mechanism (not shown) of the developing unit  34 . 
   Also, according to the present embodiment, a coagulated toner pulverizing member  65  fixed to the downstream side end part of the rotating shaft  54  for conveying the collected toner is disposed in the collected toner discharge port  57 . The coagulated toner pulverizing member  65  includes, for example, an elastic film one end of which is attached by melting to the circumferential surface of the downstream end part of the rotating shaft  54  for conveying the collected toner. The elastic film  65  abuts against the inner circumferential surface of the collected toner discharge port  57 . When rotationally driving the collected toner conveying member  53 , the elastic film  65  rotates to pulverize the coagulated toner while sliding on the inner circumferential surface of the collected toner discharge port  57 . 
   As shown in  FIGS. 7A to 9B , according to the present embodiment, the collected toner conveying path  59  is provided in the case  51  of the toner removing unit  36  so that the collected toner is conveyed by the collected toner conveying member  53 . A plurality (two in the present embodiment) of trapping sheets  70  serving as the trapping member adapted to trap foreign matters, such as fibrous dusts, are provided in the collected toner conveying path  59 . 
   The trapping sheet  70  has a sheet substrate made of a flexible or elastic material, for example, polyimide. A fixing attachment piece  72 , such as a double-sided tape is provided at one end of the sheet substrate  71 . On the other hand, a through hole  73 , through which the collected toner conveying member  53  can pass, is opened in the sheet substrate  71 . A plurality of sharp-tipped projection portions  74 , for example, triangular projection portions  74  are formed along the opening edge of the through hole  73 . 
   The shape of the opening of the through hole  73 , which is other than the projection portions  74 , is substantially circular. The opening of the through hole  73  is formed so that the diameter of the opening is slightly larger than an outside diameter d 1  of the spiral blade  55  of the collected toner conveying member  53 . A virtual circle obtained by connecting the end positions of the projection portions  74  may appropriately be selected. In consideration of the shape maintainability of the projection portions  74 , preferably, the diameter of the virtual circle is set to be larger than the outside diameter d 2  of the rotating shaft  54  of the collected toner conveying member  53 . 
   (Toner Return Mechanism) 
   A toner return mechanism  80  according to the present embodiment, which is configured to return the toner discharged from the collected toner discharge port  57  of the toner removing unit  36  to a reuse toner supply port  50  of the developing unit  34  is described below. 
   As shown in  FIGS. 4 ,  5 , and  10 , the toner return mechanism  80  is configured so that the collected toner discharge port  57  of the toner removing unit  36  and the reuse toner supply port  50  of the developing unit  34  are connected by a connecting tube  81  for conveying reuse toner, that a reuse toner conveying path  82  for conveying the toner collected by the toner removing unit  36  is formed in the connecting tube  81 , and that a conveying member  91  is disposed in the reuse toner conveying path  82 . 
   Hereinafter, the reuse toner conveying path  82  is described in detail. The reuse toner conveying path  82  is formed by connecting a first conveying path  82   a , which is downwardly inclined from the position of the collected toner discharge port  57  of the toner removing unit  36  at, for example, an angle that is equal to or less than a toner rest angle, through a bending portion  82   c  to a second conveying path  82   b  upwardly extending from the reuse toner supply port  50  of the developing unit  34 . The bottom surface of the first conveying path  82   a , and a side surface of the second conveying path  82   b , which is connected to the bottom surface of the first conveying path  82   a  and substantially vertically extends, are used as a toner conveying surface  82   d.    
   The conveying member  91  moves along the reuse toner conveying path  82 . The conveying member  91  includes a first conveying member  91   a , which reciprocates along the first conveying path  82   a  of the reuse toner conveying path  82 , and also includes a second conveying member  91   b  that is formed integrally with the first conveying member  91   a  to extend substantially vertically at the downstream side thereof in the toner conveying direction and is disposed in the second conveying path  82   b.    
   Now, the shape of the conveying member  91  is described below. 
   First, the first conveying member  91   a  has a plate-like substrate  92 , which is molded using a resin material, for example, PP. ABS, or POM, and which extends along the toner conveying direction of the first conveying path  82   a . A catching portion  93 , which has a circular catching hole  94  and serves as a driving force input portion, is provided at the upstream end in the toner conveying direction of the plate-like substrate  92 . Also, a plurality of plate-like blades  95  protruding toward the toner conveying surface  82   d  of the first conveying path  82   a  are arranged at predetermined intervals under the plate-like substrate  92 . 
   Also, a plurality of plate-like blades  95  protrude around the catching portion  93  and the plate-like substrate  92  of the first conveying member  91   a.    
   Also, the second conveying member  91   b  is formed integrally with the first conveying member  91   a  so that an obtuse angle is formed therebetween. The second conveying member  91   b  has an elongated plate-like substrate  101  whose bottom portion extends into the reuse toner supply port  50  of the developing unit  34 . A projection portion  102  protruding toward the toner conveying surface  82   d  of the second conveying path  82   b  is provided on a side surface of the plate-like substrate  101 . A toner scraping-down portion  103  is formed, for example, integrally with a part disposed in the reuse toner supply port  50  in the vicinity of the bottom end of the plate-like substrate  101 . 
   Additionally, according to the present embodiment, the catching portion  93  of the first conveying member  91   a  is driven by and connected to the collected toner conveying member  53 . The mounting of the catching portion  93  is performed by catching the support portion  58  in the catching hole  94  thereof. The catching portion  93  of the first conveying member  91   a  is turned through the support portion  58  to have a substantially circular locus or an elliptic orbit that is flattened in an up-down direction. 
   (Operation of Apparatus) 
   Next, an operation of the image forming apparatus according to the present embodiment is described below. 
   Upon completion of electrification of a surface of the photoreceptor drum  31  by the electrification unit  32 , the photoreceptor drum  31  is exposed according to input image data by the exposure unit  33  to thereby form an electrostatic latent image. On the other hand, the developing unit  34  is supplied with toner from the toner box  37 . A developer is agitated and conveyed in the developing unit  34 . The electrostatic latent image formed on the photoreceptor drum  31  is developed through the developing roll  42  of the developing unit  34 . Thus, a toner image is formed on the photoreceptor drum  31 . The formed toner image is transferred onto a sheet of paper S at a transfer part at which the transfer unit  35  abuts against the photoreceptor drum  31 . The toner image is outputted from the fixing unit  25  by being thermally fixed. On the other hand, after the transfer, the toner remaining on the photoreceptor drum  31  is peeled off the photoreceptor drum  31  and is collected by the blade  52  of the toner removing unit  36 . 
   Subsequently, the toner collected in the toner removing unit  36  is conveyed by the collected toner conveying member  53  along the collected toner conveying path  59  to the collected toner discharge port  57  of the case  51  of the toner removing unit  36 . 
   At that time, the collected toner conveying member  53  conveys foreign matters, for example, fibrous dusts together with the toner. The trapping sheet  70  is disposed on the middle portion of the collected toner conveying member  53 . Thus, when the spiral blade  55  of the collected toner conveying member  53  passes through the through hole  73  of the trapping sheet  70 , the projection portion  74  of the trapping sheet  70  touches the surface of the blade member  55  while causing flexible deformation (or elastic deformation) as the projection portion  74  of the trapping sheet  70  moves. 
   In this state, the foreign matters, such as the fibrous dusts, are caught and trapped by the projection portions  74  of the trapping sheet  70 . On the other hand, fine toner particles pass through between the projections  74  of the trapping sheet  70  without being trapped, and go to the collected toner discharge port  57 . The foreign matters trapped by the trapping sheet  70  are entwined with the projection portions  74 . Thus, the trapped foreign matters are hardly disengaged from the trapping sheet  70  and maintain the trapped state during the life of the process cartridge  30 . 
   Especially, according to the present embodiment, the trapping sheets  70  are provided at a plurality of places, so that foreign matters are effectively trapped at a plurality of places. 
   Thereafter, when the collected toner reaches the collected toner discharge port  57  of the toner removing unit  36 , the coagulated toner pulverizing member  65  pulverizes coagulated toner. Thus, the collected toner is discharged from the collected toner discharge port  84  to the toner return mechanism  80  without being coagulated. Incidentally, although the coagulated toner pulverizing member  65  is provided in the present embodiment, the present embodiment may be modified by omitting the coagulated toner pulverizing member  65 . 
   Especially, according to the present embodiment, the trapping sheet  70  allows the collected toner to pass therethrough by being uniformized, in addition to the trapping of foreign matters such as fibrous dusts. Thus, the present embodiment is preferable in that coagulated toner is pulverized to some extent when the toner passes through the trapping sheet  70 . 
   Subsequently, the collected toner is returned to the developing unit  34  through the toner return mechanism  80 . 
   At that time, as the support portion  58  turns, the conveying member  91  performs circulation movement in the toner return mechanism  80 . However, the first conveying member  91   a  performs linear movement along the toner conveying direction. Also, the first conveying member  91   a  moves in a direction opposite to the toner conveying direction so as not to follow the toner conveying surface  82   d . Thus, good toner conveyability is maintained in the first conveying path  82   a.    
   Additionally, the second conveying member  91   b  can be approached to and separated from the toner conveying surface  82   d  of the second conveying path  92   b . When contacted with the toner conveying surface  82   d , the second conveying member  91   b  rectilinearly moves. During the toner is conveyed by the first conveying member  91   a , it is advisable to make the second conveying member  91   b  away from the toner conveying surface  82   d . Thus, the toner adhering to the toner conveying surface  82   d  is effectively scraped down. Also, the free fall of the toner from the first conveying path  82   a  to the second conveying path  82   b  is not prevented. Consequently, good toner conveyability is also maintained in the second conveying path  82   b.    
   Thus, according to the present embodiment, good toner conveyability is maintained in both the first conveying path  82   a  and the second conveying path  82   b.    
   Additionally, the collected toner having been returned to the reuse toner supply port  50  of the developing unit  34  is agitated and mixed with carrier together with existing toner and supplement toner by the agitation conveying members  43  and  44 . Then, the collected toner in a sufficiently electrified state is supplied to the developing roll  42 . 
   Second Embodiment 
     FIG. 11  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a second embodiment. 
   As shown in  FIG. 11 , the basic configuration of the toner removing unit of the second embodiment is substantially the same as that of the first embodiment. However, the toner removing unit of the second embodiment uses a trapping mat  110  as the trapping member, differently from the first embodiment. 
   As shown in  FIGS. 11 and 12A , the trapping mat  110  shown according to the present embodiment is produced by forming a plurality of projection portions  112 , each of which is constituted by a sharp-tipped triangular member made of a flexible material, on a side edge of a flexible fixing attachment piece  111  (in the present embodiment, the piece  111  has a length longer than the outside circumference of the rotating shaft  54  for conveying the collected toner) such as a double-side tape. Incidentally, although the dimension of the projected part of each of the projection portions  112  may appropriately be set, this dimension is set to be longer than the length of a projected part in the radial direction of the blade member  55  according to the present embodiment. 
   Also, it is advisable for forming the trapping mat  110  to wind the flexible fixing attachment piece  111  around the collected toner conveyance rotating shaft  54  of the collected toner conveying member  53  along the spiral locus of the spiral blade  55 . The trapping mat  110  is attached around the rotating shaft  54  in a state in which the plurality of projection portions  112  are protruded in the radial direction of the rotating shaft  54 . 
   Consequently, according to the present embodiment, foreign matters such as fibrous dusts are conveyed together with toner by the collected toner conveying member  53  and are trapped by being entwined with the projection portions  112  of the trapping mat  110 . 
   Incidentally, the trapping mat according to the invention is not limited to the trapping mat  110  fixed to the collected toner conveying member  53  in the present embodiment. For example, a modification of a trapping mat is formed by implanting or fixing hook wire-like members  113  such as a plurality of bristles of a brush, which are constituted by nylon fibers, polypropylene fibers, polyester fibers, animal fibers, or plant fibers, on or to a flexible fixing attachment piece  111  and additionally forming a hook part  114  at each of end portion of the hook wire-like members  113 , as shown in  FIG. 13A . 
   It is advisable for forming the trapping mat  110  to wind the flexible fixing attachment piece  111  around the collected toner conveyance rotating shaft  54  of the collected toner conveying member  53  along the spiral locus of the spiral blade  55 , as shown in  FIG. 13B . The trapping mat  110  is attached around the rotating shaft  54  in a state in which the plurality of hook wire-like members  113  are protruded in the radial direction of the rotating shaft  54 . 
   Thus, even in the case of this modification of the first embodiment, foreign matters such as fibrous dusts are conveyed together with the toner by the collected toner conveying member  53  and are trapped by being entwined with the hook wire-like members  113  of the trapping mat  110 . 
   Third Embodiment 
     FIG. 14  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a third embodiment. 
   As shown in  FIG. 14 , the basic configuration of the toner removing unit of the third embodiment is substantially the same as that of the first embodiment. However, the third embodiment employs a trapping member different in structure from those of the first and second embodiments. 
   According to the third embodiment, the collected toner conveying member  53  is provided with spiral blades  55  around the rotating shaft  54  for conveying the collected toner. However, for example, substantially rectangular cutouts  120  are integrally formed at appropriate intervals around each of the spiral blades  55 . 
   According to the present embodiment, the cutouts  120  of the collected toner conveying member  53  also have the function of the trapping portion. Foreign matters such as fibrous dusts are conveyed together with the toner by the collected toner conveying member  53  and are trapped by being entwined with the cutouts  120 . 
   Fourth Embodiment 
     FIG. 15  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a fourth embodiment. 
   As shown in  FIG. 15 , the basic configuration of the toner removing unit of the third embodiment is substantially the same as that of the first embodiment. However, according to the fourth embodiment, both the trapping sheet  70  of the first embodiment and each of the cutouts  120  of the collected toner conveying member  53  of the third embodiment are used. 
   According to the present embodiment, the ability to trap foreign matters such as fibrous dusts are further enhanced, as compared with the first and third embodiments. 
   Fifth Embodiment 
     FIG. 16  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a fifth embodiment. 
   As shown in  FIG. 16 , the basic configuration of the toner removing unit of the fifth embodiment is substantially the same as that of the fourth embodiment. However, a collected toner conveying member  53  according to the fifth embodiment differs in configuration from that of the fourth embodiment. 
   According to the fifth embodiment, the collected toner conveying member  53  is configured so that flanges  132  and  133  having a predetermined configuration are provided at both end portions of the rotating shaft  131  for conveying the collected toner, respectively, and that a coil-like conveying member  134  having wire-like members formed around the rotating shaft is provided between the flanges  132  and  133 . Incidentally, a support portion  58  is provided at one  132  of the flanges. 
   According to the fifth embodiment, both the trapping sheet  70  according to the first embodiment and the coil-like conveying member  134  itself are utilized as the trapping members. That is, because the coil-like conveying member  134  has the spiral coil member, foreign matters such as fibrous dusts are easily entwined with the coil-like conveying member  134 . 
   Consequently, according to the fifth embodiment, foreign matters such as fibrous dusts are entwined with and are trapped by the trapping sheet  70  and the coil-like conveying member  134 . 
   Incidentally, according to the present embodiment, a mode also using the trapping sheet  70  has been described. It is apparent that the apparatus may be modified so that only the collected toner conveying member  53  having the coil-like conveying member  134  also serves as the trapping member. 
   Sixth Embodiment 
     FIG. 17  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a sixth embodiment. 
   As shown in  FIG. 17 , the basic configuration of the toner removing unit of the sixth embodiment is substantially the same as that of the first embodiment. However, the sixth embodiment employs a trapping net  140  as the trapping member, which differs from that of the first embodiment. 
   According to the sixth embodiment, the trapping net  140  has a mesh member  141  formed by causing, for example, wire-like members to intersect with one another like a lattice. A through hole  142 , through which the collected toner conveying member  53  passes, is formed in the mesh member  141 . Also, hook-like parts  143  are formed at each end portion of the mesh member  141 , which is located on an edge portion of the through hole  124 . Incidentally, according to the sixth embodiment, the diameter of the through hole  142  is set to be slightly less than the outside diameter of the spiral blade  55  of the collected toner conveying member  53 . The hook-like part  143  formed at each end portion of the mesh member  141  is contacted with the spiral blade  55  of the collected toner conveying member  53  to be able to be elastically deformable. 
   Consequently, according to the sixth embodiment, foreign matters such as fibrous dusts are entwined with and are trapped by the hook-like parts  143  of the trapping net  140 . 
   Seventh Embodiment 
     FIG. 18A  is an explanatory view illustrating the configuration of the periphery of a collected toner conveying member of a toner removing unit used in a seventh embodiment. 
   As shown in  FIG. 18A , the basic configuration of the toner removing unit  36  of the seventh embodiment is substantially the same as that of the first embodiment. However, the seventh embodiment employs a trapping mat  150  as the trapping member, which differs from that of the first embodiment. 
   According to the seventh embodiment, the trapping mat  150  is provided to extend along the longitudinal direction of an entrance-side wall surface (for example, a wall surface extending in an up-down direction) of the collected toner conveying member  53  in the case  51  of the toner removing unit  36 , as shown in  FIG. 18A . Although a blade  52  is attached to the case  51  through a bracket  155  in the seventh embodiment, the bracket  155  substantially constitutes a part of the case  51 . 
   Incidentally, as shown in  FIG. 18B , the trapping mat  150  is formed by implanting or fixing hook wire-like members  153  such as a plurality of bristles of a brush, which are constituted by nylon fibers, polypropylene fibers, polyester fibers, animal fibers, or plant fibers, on or to a flexible fixing attachment piece  151  and additionally forming a hook-like part  154  at each of end portion of the hook wire-like members  153 . 
   Accordingly, according to the present embodiment, when foreign matters such as fibrous dusts enter the case  51  from an opening thereof while residual toner is collected by the blade  52  of the toner removing unit  36 , the foreign matters are trapped by the trapping mat  150  provided just posterior to the opening of the case  51 . 
   Additionally, when the foreign matters such as fibrous dusts are floated while conveyed together with toner by the collected toner conveying member  53 , the foreign matters are trapped by the trapping mat  150 . 
   Although the trapping mat  150  is provided to continuously extend corresponding to the width of an opening of the case  51 , the trapping member according to the invention is not limited thereto. The trapping mat  150  may be discontinuously provided. 
   Eighth Embodiment 
     FIG. 19A  is an explanatory view illustrating the configuration of a developing unit used in an eighth embodiment. 
   As shown in  FIG. 19A , the basic configuration of the developing unit  34  of the eighth embodiment is substantially the same as that of the first embodiment. However, the eighth embodiment differs from the first embodiment in that a trapping sheet  160  is provided as the trapping member in the developing unit  34 . Incidentally, constituting elements similar to those of the first embodiment are designated by similar reference numerals used in the description of the first embodiment. Thus, the detailed description of such constituent elements is omitted herein. 
   As shown in  FIG. 19B , the trapping sheet  160  has a sheet substrate  161  made of a flexible or elastic material, for example, polyimide. A fixing attachment piece  162  such as a double-sided tape is provided at one end of the sheet substrate  161 . On the other hand, a substantially semicircular opening  163 , through which the collected toner conveying member  53  can pass, is opened in the sheet substrate  161 . A plurality of sharp-tipped projection portions  164 , for example, triangular projection portions  164  are formed along the opening edge of the opening  163 . 
   According to the eighth embodiment, the trapping sheet  160  is configured so that the fixing attachment piece  161  of the trapping sheet  160  is fixed to an upper wall inner surface of a developer accommodating container  41  of a developer circulation path  48  at the side at which, for example, one  44  of agitation conveying members of the developing unit  34 , and that the trapping sheet  160  is suspended therefrom. Incidentally, because the circulation conveyance of a predetermined amount of the developer G is performed in a developer circulation path  48  shown in  FIG. 19B , it is advisable to dispose the trapping sheet  160  in an upper space which is filled with at least the developer. 
   At that time, the agitation conveying member  44  passes through the opening  163  of the trapping sheet  160  and conveys the developer including the toner and the carrier while causing a trapping portion  164  to elastically deform. In such an operation process, it is frequent that foreign matters such as fibrous dusts move in a state in which the foreign matters are floated above the developer, and that the foreign matters are dammed and are trapped by the trapping sheet  160 . 
   Also, in a case where the eighth embodiment is modified so that, for example, the developer accommodating container  41  is divided into upper and lower housings, when the upper housing of the developer accommodating container  41  is removed, foreign matters trapped by the trapping sheet  160  can be cleaned. Additionally, the eight embodiment may be modified so that, for example, when the developer in the developing unit  34  is replaced, the upper housing of the developer accommodating container  41  is removed, and that simultaneously with replacement of the developer, the trapping sheet  160  provided in the housing is replaced with new one. 
   Ninth Embodiment 
     FIG. 20A  is an explanatory view illustrating the configuration of a developing unit used in a ninth embodiment. 
   As shown in  FIG. 20A , the basic configuration of the developing unit  34  of the ninth embodiment is substantially the same as that of the eighth embodiment. However, the ninth embodiment differs from the eighth embodiment in that a trapping sheet  170  is provided as the trapping member in the developing unit  34 . Incidentally, constituting elements similar to those of the eighth embodiment are designated by similar reference numerals used in the description of the eighth embodiment. Thus, the detailed description of such constituent elements is omitted herein. 
   As shown in  FIG. 20B , the trapping mat  170  is formed by implanting or fixing hook wire-like members  173  such as a plurality of bristles of a brush, which are constituted by nylon fibers, polypropylene fibers, polyester fibers, animal fibers, or plant fibers, on or to a flexible fixing attachment piece  171  and additionally forming a hook-like part  174  at each of end portion of the hook wire-like members  173 . 
   According to the ninth embodiment, the trapping sheet  170  is configured so that the fixing attachment piece  171  of the trapping sheet  170  is fixed to an upper wall inner surface of a developer accommodating container  41  of a developer circulation path  48  at the side at which, for example, one  44  of agitation conveying members of the developing unit  34 , and that the hook wire-like members  173  are disposed on the inner wall surface of the developer accommodating container  41  to protrude therefrom. 
   Although an amount of projection of each of the hook wire-like members  173  can be set so that the hook wire-like members  173  are contacted with the developer G in the developer circulation path  48 , preferably, to trap the floated foreign matters such as fibrous dusts, the hook wire-like members  173  are disposed so as not to be contacted with the developer G. 
   Accordingly, according to the ninth embodiment, the agitation conveying member  44  conveys the developer (including toner and carrier) in the developer circulation path  48 . In such an operation process, it is frequent that foreign matters such as fibrous dusts move in a state in which the foreign matters are floated above the developer, and that the foreign matters are dammed and are trapped by the hook wire-like members  173  of the trapping mat  170 . 
   Substantially similarly to the eighth embodiment, in the case of the ninth embodiment, the cleaning and the replacement of the trapping mat  170  can easily be performed, for example, by removing the upper housing of the developer accommodating container  41  of the type that is divided into upper and lower housings. 
   The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.