Patent Publication Number: US-8543035-B2

Title: Cleaning device, cartridge and image forming apparatus

Description:
FIELD OF THE INVENTION AND RELATED ART 
     The present invention relates to a cleaning device for removing a developer from an image bearing member for use in an image forming apparatus. As the image forming apparatus, there is an electrophotographic image forming apparatus of an electrophotographic type such as a copying machine, a laser printer or a facsimile machine. Further, the present invention relates to a cartridge including such a cleaning device and relates to an image forming apparatus including the cartridge. 
     Here, in the present invention, the electrophotographic image forming apparatus forms an image on a recording material (e.g., paper, OHP sheet, etc.) by using an electrophotographic process. Examples of the electrophotographic image forming apparatus may include an electrophotographic copying machine, an electrophotographic printer (e.g., a laser beam printer, an LED printer, etc.), a facsimile machine, a word processor, and the like. 
     Further, the cartridge refers to a member constituted by integrally assembling members used for the image forming apparatus and is provided detachably mountable to the image forming apparatus. A process cartridge is a cartridge prepared by integrally assembling a charging means, a developing means or a cleaning means which are process means, and an electrophotographic photosensitive drum, and is detachably mountable to an electrophotographic image forming apparatus main assembly. The process cartridge is also a cartridge prepared by integrally assembling at least one of the charging means, the developing means and the cleaning means which are as the process means, and the electrophotographic photosensitive drum, and is detachably mountable to the electrophotographic image forming apparatus main assembly. 
     In the conventional electrophotographic image forming apparatus as described above, the electrophotographic photosensitive drum uniformly charged by the charging means is subjected to selective exposure to form an electrostatic latent image. Then, the electrostatic latent image is developed by the developing means into a visible image (developer image). Thereafter, the developer image is transferred onto recording paper (recording material) to be formed on the recording paper as an image. The electrophotographic photosensitive drum after being subjected to the developer image transfer is subjected to removal of developer remaining on a surface thereof by the cleaning means, and then goes to a subsequent image formation. Incidentally, the developer removed from the electrophotographic photosensitive drum surface by the cleaning means is accommodated in a removed developer accommodating container. 
     As a cleaning device constituting the cleaning means, a blade-like cleaning blade constituted by a supporting member formed with a metal plate or the like containing iron as a main component and by an elastic blade formed of an urethane rubber or the like has be generally used. The cleaning blade is positioned and mounted on a cleaning container, with high accuracy, formed with a resin member of PS (polystyrene), ABS (acrylonitrile-butadiene-styrene) or the like. As a result, the cleaning blade is contacted to the electrophotographic photosensitive drum with a predetermined penetration depth and a set angle, thus removing the developer remaining on the electrophotographic photosensitive drum. 
     As described above, in order that the cleaning blade achieves a sufficient cleaning effect, an edge portion of the elastic blade is required to be contacted to the electrophotographic photosensitive drum with high positional accuracy. However, when a temperature is fluctuated by a change in environment or an operation of the image forming apparatus, parts for constituting the cleaning device are constituted by different materials and thermal expansion coefficient is different depending on the parts. Therefore, there arises a difference in amount of thermal expansion and contraction, so that there is a possibility of an occurrence of deformation. 
     In order to suppress these deformations, a thickness of the metal plate has been conventionally increased. Further, as another means for enhancing a strength of the metal plate, the metal plate has been conventionally subjected to a plurality of bending processes. 
     Further, according to a conventional technique, as described in Japanese Laid-Open Patent Application 2000-19930, a constitution in which a reinforcing member having the thermal expansion coefficient equivalent to that of the supporting member for the cleaning blade is provided on an opposite side to the cleaning blade via the cleaning device has been proposed. As a result, the deformation, such as curvature, of the cleaning blade caused by a difference in thermal expansion coefficient (bimetal) can be restricted and suppressed by the members (the supporting member and the reinforcing member) provided on both sides while sandwiching the cleaning device. 
     However, these means are disadvantageous in terms of cost, and weight reduction and downsizing of the cleaning device. 
     SUMMARY OF THE INVENTION 
     A principal object of the present invention is to provide a cleaning device which has solved the problems of the conventional technique and has improved on the conventional technique. 
     That is, an object of the present invention is to provide a cleaning device having realized a reduction in a fluctuation itself of a cleaning blade (elastic blade) due to a temperature change. Further to say, another object of the present invention is to provide a cleaning device capable of stably maintaining a cleaning performance while suppressing fluctuations in penetration amount and set angle of the elastic blade with respect to an image bearing member, due to the temperature change, at the minimum. 
     A further object of the present invention is to provide a cartridge and an image forming apparatus which include the above-improved cleaning device. 
     According to an aspect of the present invention, there is provided a cleaning device for removing a developer remaining on an image bearing member from the image bearing member, the cleaning device comprising: 
     cleaning means, including an elastic blade elastically contacted to the image bearing member and a supporting member for supporting the elastic blade, for removing the developer remaining on the image bearing member from the image bearing member; 
     an image bearing member bearing member including a supporting portion for rotatably supporting the image bearing member; and 
     a removed developer accommodating container formed of a material having a thermal expansion coefficient different from that of a material for the supporting member, the removed developer accommodating container including an accommodating portion for accommodating the developer removed by the cleaning means, 
     wherein the image bearing member bearing member is fixed to the supporting member, 
     wherein the removed developer accommodating container is fixed to the supporting member, and 
     wherein the image bearing member bearing member and the removed developer accommodating container are provided with a gap therebetween with respect to a longitudinal direction of the supporting member. 
     According to another aspect of the present invention, there is provided a cleaning device for removing a developer remaining on an image bearing member from the image bearing member, the cleaning device comprising: 
     cleaning means, including an elastic blade elastically contacted to the image bearing member and a supporting member for supporting the elastic blade, for removing the developer remaining on the image bearing member from the image bearing member; 
     an image bearing member bearing member including a supporting portion for rotatably supporting the image bearing member; and 
     a removed developer accommodating container formed of a material having a thermal expansion coefficient different from that of a material for the supporting member, the removed developer accommodating container including an accommodating portion for accommodating the developer removed by the cleaning means, 
     wherein the image bearing member bearing member is fixed at longitudinal ends of the supporting member, 
     wherein the removed developer accommodating container is fixed to the image bearing member bearing member fixed at one longitudinal end of the supporting member, and 
     wherein the image bearing member bearing member fixed at the other longitudinal end of the supporting member and the removed developer accommodating container are provided with a gap therebetween with respect to a longitudinal direction of the supporting member. 
     These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional side view showing a general structure of an electrophotographic image forming apparatus according to an embodiment of the present invention. 
         FIG. 2  is a sectional side view showing a general structure of a process cartridge according to the embodiment of the present invention. 
         FIGS. 3 and 4  are perspective views showing a general structure of the process cartridge. 
         FIG. 5  is a sectional side view showing setting of a cleaning blade. 
         FIG. 6  includes an exploded view and an assembling view which show a general structure of a cleaning device in Embodiment 1. 
         FIGS. 7 to 10  are schematic sectional views showing a procedure of assembling of the cleaning device in Embodiment 1. 
         FIG. 11  is a schematic sectional view showing an end portion structure of a removed developer accommodating container in Embodiment 1. 
         FIG. 12  includes an exploded view and an assembling view which show a general structure of a cleaning device in Comparative Embodiment. 
         FIG. 13  is a schematic sectional view showing a structure of the cleaning device in Comparative Embodiment. 
         FIGS. 14 to 21  are schematic sectional views showing structures of cleaning devices in Embodiments 2 to 9, respectively. 
         FIG. 22  is a perspective view showing an end lo portion of a supporting member in the cleaning device in Embodiment 9. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Next, a cleaning device, a process cartridge and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable according to an embodiment of the present invention will be described with reference to the drawing. Incidentally, in this embodiment, the electrophotographic image forming apparatus configured to form an image on an electrophotographic photosensitive drum using an electrophotographic image forming process and a process cartridge detachably mounted to the electrophotographic image forming apparatus are described as an example. 
     (General Structure of Electrophotographic Image Forming Apparatus) 
     First, a general structure of an electrophotographic image forming apparatus A will be described with reference to  FIGS. 1 and 2 . 
     Incidentally,  FIG. 1  is a sectional side view, of the image forming apparatus, showing a state in which a process cartridge B is mounted thereto.  FIG. 2  is a sectional side view of the process cartridge B. 
     Image formation by the electrophotographic image forming apparatus A in this embodiment will be described. 
     First, as illustrated in  FIG. 1 , a laser light image formed based on image information is irradiated from an optical system  1  onto an electrophotographic photosensitive member (image bearing member), i.e., an electrophotographic photosensitive drum (hereinafter referred to as a “photosensitive drum”)  7 , which is shaped in a drum-like shape having a photosensitive layer. Thus, an electrostatic latent image is formed on the photosensitive drum  7 . Voltage is applied to a developing roller  10   d , which constitutes a developing device as a developing means and which is a developer carrying member for carrying thereon a developer t, and thus the developer t is transferred onto the photosensitive drum  7  from the developing roller  10   d . Thus, an image of the developer t is formed on the photosensitive drum  7 . 
     A recording material  2 , which is a recording medium (a recording sheet, an overhead projector (OHP) sheet, or the like), is conveyed from a cassette  3   a  by a conveying means  3   b  in a direction indicated by an arrow E in synchronization with the forming of the developer image, and is guided by a first guide plate  3   f   1  to be conveyed to an image forming portion. Then, the developer image, which is formed on the photosensitive drum  7  by the image forming portion provided as a process cartridge (hereinafter simply referred to as a “cartridge”) B, is transferred onto the recording material  2  by application of a voltage to a transfer roller  4 , which is a transfer means. The recording material  2  is then guided by a second guide plate  3   f   2  to be conveyed to a fixing means  5 . The fixing means  5  includes a driving roller  5   a  and a fixing roller  5   c  containing a heater  5   b . The recording material  2 , which has passed through the fixing roller  5   c , is conveyed by a discharging roller pair  3   d  and then is discharged to a discharge portion  6 . Incidentally, in the electrophotographic image forming apparatus A, the recording material  2  can be manually fed via a manual feed tray (not shown) and a roller (not shown). 
     (Structure of Cartridge) 
     In this embodiment, the cartridge B includes the photosensitive drum  7  and a process means, which includes at least a cleaning device  11  as a cleaning means provided with a cleaning blade  15  for removing a developer remaining on the photosensitive drum  7  from the photosensitive drum  7 . 
     As illustrated in  FIG. 2 , when the image is formed by using the cartridge B, the photosensitive drum  7  rotates in a direction indicated by an arrow R. The surface of the photosensitive drum  7  is evenly charged by a charging roller  8  as a charging means. 
     Then, light emitted from the optical system  1  passes through an exposure opening portion  9   b  included in the cleaning device  11  as a photosensitive member frame member, so as to expose the circumferential surface of the photosensitive drum  7 . An electrostatic latent image is thus formed on the photosensitive drum  7 . 
     A developing container  10  includes a developer regulating member (developing blade)  10   e  and the developing roller  10   d . Further, the developing container  10  includes a developer storing portion  10   f  for storing the developer t to be supplied to the developing roller  10   d . The developer t on the developing roller  10   d  is regulated by the developing blade  10   e , and thus an even developer layer is formed on the developing roller  10   d . By applying a developing bias (voltage) to the developing roller  10   d , the developer t is transferred onto the photosensitive drum  7  depending on the formed latent image. Thus, a developer image depending on the latent image is formed on the photosensitive drum  7 . The formed developer image is transferred onto the recording material  2  by applying a transfer bias (voltage) to the transfer roller  4  ( FIG. 1 ). 
     As shown in  FIG. 2 , the developer remaining on the surface of the photosensitive drum  7  after the developer image is transferred onto the recording material  2  is removed by a cleaning blade  15  of the cleaning device  11 . The removed developer is collected into a removed developer accommodating portion (e.g., container)  21 . The removed developer accommodating container  21  is provided with a sheet member  51 , for collecting the removed developer, at an upstream position of the photosensitive drum  7  with respect to the rotational direction R. Further, a seal member  11   d  is provided between the removed developer accommodating container  21  and the cleaning blade  15  so that the removed developer accommodated in the removed developer accommodating container  21  is not leaked. 
     A protective shutter  12  is attached to the cleaning device  11  for the purpose of protecting the photosensitive drum  7 . The protective shutter  12  is located at a protective position (not shown) in which the photosensitive drum  7  is covered when the cartridge B is not in use. The protective shutter  12  is provided rotatable between the protective position and an exposure position in which the photosensitive drum  7  is exposed from the surface of the cartridge B when the cartridge B is in use (when the cartridge B is mounted in the image forming apparatus main assembly) as illustrated in  FIG. 2 . 
       FIG. 3  is a perspective view showing a general structure of the process cartridge in this embodiment. 
     As illustrated in  FIG. 3 , the cartridge B includes a cleaning unit v as a first unit, a developing unit u as a second unit, and a drum holder  13 . 
     The cleaning unit v includes the removed developer accommodating container  21 , an electrophotographic photosensitive drum bearing member (hereinafter referred to as a “drum bearing member”) (driving side)  22  and an electrophotographic photosensitive drum bearing member (hereinafter referred to as a “drum bearing member”) (non-driving side)  23 . The electrophotographic photosensitive drum bearing members  22  and  23  are image bearing member bearing members. Further, the cleaning unit v includes the photosensitive drum  7 , the charging roller  8 , and the cleaning blade  15 . 
     The developing unit u includes a development frame member and the developing roller  10   d  ( FIG. 2 ). The development frame member includes the developing container  10  and end portion members  81  and  82 . The end portion members  81  and  82  are fixed at both ends of the developing container  10  in the longitudinal direction thereof, and the development frame member (the positioning container  10  and the end portion members  81  and  82 ) rotatably supports both ends of the developing roller  10   d  ( FIG. 2 ) in the longitudinal direction. Further, the drum holder  13  is fixed to the cleaning device  11  and rotatably supports the photosensitive drum  7  and the developing unit u. 
     Next, a constitution for supporting the developing unit u with the cleaning unit v will be described. 
     As illustrated in  FIG. 3 , the developing unit u includes the developing container  10  and the end portion members  81  and  82 . As described above, the end portion members  81  and  82  are attached to the developing container  10  in the longitudinal direction of the developing container  10 , respectively. Further, the end portion members  81  and  82  include an arm portion  81   a  and an arm portion  82   a , respectively. Here, the arm portions  81   a  and  82   a  protrude towards the cleaning unit v (in a direction crossing the longitudinal direction of the developing container  10 ). At front edges of the arm portions  81   a  and  82   a , a one-end rocking (fulcrum) shaft  81   b  as a one-end portion to be supported (one-end supported portion), and another-end rocking (fulcrum) shaft  82   b  as an another-end portion to be supported are respectively provided. In this embodiment, the rocking shafts  81   b  and  82   b  are cylindrically shaped. 
     At the other end, the photosensitive drum  7  is rotatably supported by a drum shaft  14  as a photosensitive member supporting portion provided on the cleaning device  11 . 
     The drum shaft  14  is press-fit in a hole (not shown) provided on a first portion to be guided (first guided portion)  11   f . The first guided portion  11   f  is disposed at the other end of the cleaning device  11 . Further, at the one end, the photosensitive drum  7  is rotatably supported by a drum supporting portion  13   h  as a second supporting portion. Here, the drum holder  13  attached to the cleaning device  11  at the one end includes the drum supporting portion  13   h . The cleaning device  11  rotatably supports the photosensitive drum  7  via the drum holder  13  at the one end and rotatably supports the photosensitive drum  7  by the drum shaft  14  at the other end. 
     Further, at the other end, the cleaning device  11  has a fitting (engaging) hole  11   e  as another end supporting portion. Further, the drum holder  13  has a fitting hole  13   c  as a first supporting portion. The fulcrum shafts  81   b  and  82   b  are fitted in the fitting holes  13   c  and  11   e , respectively. Thus, at the one end, the fitting hole  13   c  swingably supports the fulcrum shaft  81   b  (i.e., the drum holder  13  swingably supports the development frame member at the one end), and at the other end, the fitting hole  11   e  rotatably supports the fulcrum shaft  82   b . That is, the developing unit u is rotatably (swingably) supported by the cleaning unit v. 
     As this time, the position of the arm portion  81   a  as a portion to be restricted (restricted portion) in the longitudinal direction is restricted between a longitudinal direction restriction portion (not shown), which is provided on the cleaning frame member  11  at the one end, and an arm abutting portion (not shown), which is a restriction portion provided on the drum holder  13 . Thus, the position of the developing unit u in the longitudinal direction with respect to the cleaning unit v is restricted. 
       FIG. 4  is a perspective view showing a general structure of the process cartridge B in this embodiment. 
     As illustrated in  FIG. 4 , compression coil springs  85  and  86  as a biasing member are fit around spring holders  83  and  84  ( FIG. 3 ), which are provided on the end portion members  81  and  82 , respectively. The springs  85  and  86  are disposed (compressed) between each of the end portion members  81  and  82  and the cleaning device  11 . Thus, the developing unit u is urged towards the photosensitive drum  7 , and a ring-like gap maintaining member  10   c  ( FIG. 2 ), which is provided on both ends of the developing roller  10   d , contacts the photosensitive drum  7 . Thus, the developing roller  10   d  and the photosensitive drum  7  oppose each other with a predetermined gap. 
     By employing the above-described constitution, according to this embodiment, the cleaning unit v can swingably support the developing unit u without the need to use a connection pin or the like. In addition, at the above-described other end, the drum holder  13  supports both the photosensitive drum  7  and the developing unit u (the fulcrum shaft  81   b ). Accordingly, the relative position of the photosensitive drum  7  to the developing roller  10   d , which is supported by the developing unit u, can be accurately determined. 
     Furthermore, as shown in  FIG. 3 , to transfer (input) a driving force from an electrophotographic image forming apparatus (hereinafter referred to as an “apparatus main assembly”) Aa to the photosensitive drum  7 , a drum gear  7   a  is provided on the photosensitive drum  7  at the one end. In addition, to transfer the driving force from the apparatus main assembly Aa to the developing roller  10   d  ( FIG. 2 ), a developing roller gear (not shown) is attached to the one end of the developing roller  10   d  in the longitudinal direction. In addition, an idler gear (not shown) for transferring the driving force from the developing roller gear to a conveyance gear (not shown) connected to a developer conveyance member  39  ( FIG. 2 ) is provided at the one end. The end portion member  81  covers a gear train (not shown) including the developing roller gear, the conveyance gear, and the idler gear. 
     (Detail Structure of Cleaning Device) 
     Next, a detail structure of the cleaning device  11  will be described. 
       FIG. 5  is a sectional side view of the cleaning portion only which is enlarged in the sectional side view of  FIG. 2  showing the general structure of the cartridge B. 
     First, with reference to  FIG. 5 , cleaning setting will be described. 
     The cleaning blade  15  is constituted by an elastic blade  15   a  elastically contacted to the photosensitive drum  7  and a supporting member  15   b  for supporting the elastic blade  15  in order to remove the developer remaining on the photosensitive drum  7 . The elastic blade  15   a  is formed with a polyurethane rubber and is integrally held at a front end portion of the supporting member  15   b  formed with a metal plate containing metal as a main component, thus being contacted to the surface of the photosensitive drum  7  from a direction opposite from the rotational direction R (i.e., in a counter direction) with a predetermined penetration amount (depth) δ and a predetermined set angle θ. 
     Here, the penetration amount δ is entering length of a front end surface of the elastic blade  15   a  when the front end surface of the elastic blade  15   a  is assumed to enter the photosensitive drum  7  as it is without being deformed. Further, the set angle θ is an angle formed between an axial line of the elastic blade  15   a  and a tangent line at a point of intersection of the photosensitive drum  7  and the front end surface of the elastic blade  15   a.    
     The penetration amount δ and the set angle θ which are two parameters for determining the setting of the cleaning blade  15  are required to be maintained with high precision. This is because when the penetration amount δ and the set angle θ are largely fluctuated by external factors, the removed developer passes through the elastic blade  15   a , so that there is a possibility of an occurrence of defective cleaning by which a print image is contaminated. Further, this is also because the elastic blade  15   a  is turned up by the rotation of the photosensitive drum  7  and thus there is a possibility that the defective cleaning occurs. 
     The present invention will be described more specifically based on Embodiments. 
     Before Embodiments of the present invention is specifically described, in order to clarify a structural feature in Embodiments of the present invention, first, a cleaning device according to Comparative Embodiment will be described. 
     (Comparative Embodiment) 
       FIG. 12  illustrates a structure of a cleaning device  11  in Comparative Embodiment. In  FIG. 12 , an exploded view of the cleaning device  11  before assembling is shown as an upper view, and a final view of the cleaning device  11  after the assembling is shown as a lower view. 
       FIG. 13  is a schematic sectional front view of the cleaning device  11 , after the assembling in  FIG. 12 , cut along a plane which passes through a center of axis of the photosensitive drum  7  and is perpendicular to the supporting member  17   b  of the cleaning blade.  FIG. 13  schematically illustrates only a portion relating to the present invention. 
     As shown in the upper view (before the assembling), the cleaning device  11  is principally constituted by a cleaning container  31  and a cleaning blade  17  which is constituted by an elastic blade  17   a  and a supporting member  17   b.    
     Here, the cleaning container  31  is provided with a seal member  11   d  so that the removed developer is leaked. 
     The supporting member  17   b  is screwed and fixed with tap tight screws  18   a  and  18   b  on bearing surfaces  31   a  and  31   b  located at both end portions in the longitudinal direction (longitudinal end portions) of the cleaning container  31 , at one end in the longitudinal direction (longitudinal one end) and at another end in the longitudinal direction (longitudinal another end). At that time, the screws  18   a  and  18   b  are inserted into holes  17   e  and  17   f  provided in the supporting member  17   b  and then are screwed into holes  31   c  and  31   d  provided in the bearing surfaces  31   a  and  31   b.    
     In  FIG. 12 , the position of the cleaning blade  17  in the cleaning container  31  with respect to the longitudinal direction (a direction indicated by an arrow X) is determined by engaging a positioning pin  31   e , provided on the bearing surface  31   a , with an elongated circular hole  17   g  provided in the supporting member  17   b . Further, the position of the cleaning container  31  with respect to a widthwise direction (a direction indicated by an arrow Y) is determined by engaging rectangular basses  31   f  and  31   g  ( FIG. 13 ), provided on the bearing surfaces  31   a  and  31   b , with cuts  17   h  and  17   i  provided in the supporting member  17   b . Further, the position of the cleaning blade  17  in the cleaning container  17  with respect to a height direction (a direction indicated by an arrow Z) is determined by the height of the bearing surfaces  31   a  and  31   b . Thus, the cleaning blade  17  is contacted to the photosensitive drum  7  with high accuracy. 
     The assembling of the photosensitive drum  7 , the drum shaft  14  and the drum holder  13  is similar to that in the method as described above in (Structure of cartridge) in the embodiment of the present invention. The lower view of  FIG. 12  illustrates the cleaning device  11  after these parts are assembled. However, from  FIG. 12 , the assembling of the developing unit performed simultaneously by the assembling of the charging roller and the drum holder  13  is omitted. 
     In order to achieve a sufficient cleaning effect of the cleaning blade, an edge portion of the elastic blade is required to contact the electrophotographic photosensitive drum with high positional accuracy. However, when a temperature is fluctuated by a change in environment or an operation of the electrophotographic image forming apparatus, the parts constituting the cleaning device are constituted by different materials and thus are different in thermal expansion coefficient depending on the materials. For this reason, there arises a difference in thermal expansion and contraction amount, so that deformation occurs. 
     Particularly, the cleaning container  31  (resin) and the supporting member  17   b  (metal plate) of the cleaning blade  17  are, as shown in  FIG. 12 , screwed and fixed at two points which are remote from each other. For that reason, due to the difference in thermal expansion coefficient, bimetal (phenomenon) occurs, so that the cleaning blade  17  is curved or bent to cause fluctuations in penetration amount and set angle in some cases. The bimetal (phenomenon) is bending of a connecting member due to a change in temperature when members different in thermal expansion coefficient are connected with each other. 
     The supporting member  17   b  used in the cleaning device in Comparative Embodiment is formed with a zinc-coated steel having the thermal expansion coefficient of 1.2×10 −5 /° C., and the cleaning container  31  is formed of a PS (polystyrene) resin material having the thermal expansion coefficient of 8.7×10 −5 /° C. 
     (Embodiment 1) 
     The cleaning device  11  to which the present invention is applicable will be descried more specifically with reference to  FIG. 6  and  FIGS. 7 to 10 . 
       FIG. 6  illustrates the cleaning device  11  to which the present invention is applicable in this embodiment, wherein an exploded view of the cleaning device  11  before assembling is shown as an upper view, and a final view of the cleaning device  11  after the assembling is shown as a lower view. However, from 
       FIG. 6 , the assembling of the developing unit performed simultaneously by the assembling of the charging roller and the drum holder  13  is omitted. 
       FIGS. 7 to 10  shows the structure of the cleaning device  11  to which the present invention is applicable in the order of assembling steps. In each of  FIGS. 7 to 10 , only the portions relating to the present invention are schematically illustrated in a left view showing a cross section taken along A-A line in  FIG. 6  and in a right view showing a cross section taken along B-B line in the A-A cross section. 
     As shown in the upper view (before the assembling) of  FIG. 6 , the cleaning device  11  includes the cleaning blade  15  principally constituted by the elastic blade  15   a  and the supporting member  15   b . Further, the cleaning device  11  is constituted by including the drum bearing members  22  and  23  to be attached to both end portions in the longitudinal direction (longitudinal end portions) of the supporting member  15   b  and including the removed developer accommodating container  21  which is an accommodating portion for accommodating the removed developer. Here, the removed developer accommodating container  21  is provided with the seal member  11   d  (which is shown in  FIG. 6  but is not shown in  FIGS. 7 to 10 ) so that the removed developer is not leaked. 
     Further, the photosensitive drum  7  includes the drum-like photosensitive layer  7   d  into which the developer  7   a  and a drum flange  7   b  are press-fitted and fixed at both end opening portions of the photosensitive drum  7 . The drum gear  7   a  includes a drive transmitting portion (coupling)  7   c  to which the driving force is inputted from a main assembly drive input portion (not shown). Hereinafter, one end at which the drive transmitting portion  7   c  is provided is referred to as a driving side, and the other end is referred to as a non-driving side. In accordance with this, the drum bearing member  22  is a drum bearing member (driving side), and the drum bearing member  23  is a drum bearing member (non-driving side). 
     With reference to  FIGS. 7 to 10 , the structure of the cleaning device  11  to which the present invention is applicable will be described in the order of assembling. 
     In step  1  ( FIG. 7 ), on the driving side at the one end in the longitudinal direction of the supporting member  15   b  and on the non-driving side at the other end in the longitudinal direction of the supporting member  15   b , the drum bearing member (driving side)  22  and the drum bearing member (non-driving side)  3  are fixed to the supporting member  15   b .  FIG. 7  corresponds to the exploded view of the cleaning device  11  before the assembling shown in the upper view of  FIG. 6 . 
     As an example of a fixing method, the bearing surfaces  22   a  and  23   a  of the respective drum bearing members are aligned with the supporting member  15   b  and then are screwed and fixed with the tap tight screws  16   a  and  16   b . The screws  16   a  and  16   b  are inserted into holes  15   e  and  15   f  provided in the supporting member  15   b  and then are screwed into the holes  22   b  and  23   b  provided in the bearing surfaces  22   a  and  23   a . Here, a head shape of the screws  16   a  and  16   b  is not particularly limited. 
     At that time, a positioning method of each of the drum bearing members  22  and  23  relative to the supporting member  15   b  in each of the directions (indicated by the arrows X, Y and Z) is the same as that performed with respect to the cleaning blade  17  in the cleaning container  31  in Comparative Embodiment described above. 
     The position of each of the drum bearing members  22  and  23  to the supporting member  15   b  with respect to the longitudinal direction (the arrow X direction) is determined by engaging a positioning pin (not shown), which is an engaging portion provided on each of the bearing surfaces  22   a  and  23   a , with an elongated circular hole which is a portion to be engaged provided in the supporting member  15   b . Further, the position of each of the drum bearing members  22  and  23  to the supporting member  15   b  with respect to the widthwise direction (the arrow Y direction) is determined by engaging a rectangular boss (not shown), which the engaging portion provided on each of the bearing surfaces  22   a  and  23   a , with a cut (not shown) which is the portion to be engaged provided in the supporting member  15   b . Further, the position of each of the drum bearing members  22  and  23  to the supporting member with respect to the height direction (the arrow Z direction) is determined by the height of each of the bearing surfaces  22   a  and  23   a . Thus, the cleaning blade  15  is contacted to the photosensitive drum  7  with high accuracy. 
     As another method, the positioning of each of the drum bearing members  22  and  23  with respect to a planar direction (the arrow XY direction) of the supporting member  15   b  may also be performed by effecting alignment of mutual parts with unshown positioning jigs and then may be fixed with screws. As a result, there is no need to ensure a space in a positioning shape, so that it is possible to downsize the parts. 
     Further, an adhesive may also be used without using fastening parts such as screws. As a result, it is possible to eliminate the fastening parts to realize a reduction in the number of parts. Next, in Step s ( FIG. 8 ), the removed developer accommodating container  21  is assembled to the supporting member  15   b.    
     The position of the removed developer accommodating container  21  to the supporting member  15   b  with respect to the longitudinal direction (the arrow X direction) is determined by engaging a positioning pin (engaging portion)  21   c , provided on the bearing surface  21   a , with an elongated circular hole (portion to be engaged) provided in the supporting member  15   b.    
     Here, the cleaning device  11  includes positioning pins (engaging portion)  21   d  and  21   e  at end portions of the removed developer accommodating container  21  and corresponding positioning guides (portion to be engaged)  22   c  and  23   c  provided on the drum bearing members  22  and  23 . This is because positioning stability at the end portions of the removed developer accommodating container  21  is improved. 
     The positioning guides (portions to be engaged)  22   c  and  23   c  have abutment surfaces against which the positioning pins (engaging portions)  21   d  and  21   e  are to be abutted with respect to the widthwise and height directions (the arrow YZ directions) of the supporting member  15   b . By the abutment of the positioning pins (engaging portions)  21   d  and  21   e  against the abutment surfaces, the removed developer accommodating container  21  is positioned to the drum bearing members  22  and  23  with respect to the widthwise and height directions (the arrow YZ directions) of the supporting member  15   b . Further, in order to further improve the positioning stability at the end portions of the removed developer accommodating container  21 , the following constitution is employed. That is, in this embodiment, separately from the combination for the above-described positioning, positioning pins (engaging portion)  21   f  and  21   g  are provided at the end portions of the removed developer accommodating container  21  and corresponding positioning guides (portions to be engaged)  22   d  and  23   d  are provided on the drum bearing members  22  and  23 . The positioning guides  22   d  and  23   d  have abutment surfaces against which the positioning pins  21   f  and  21   g  are to be abutted with respect to the height directions (the arrow Z direction) of the supporting member  15   b . By the abutment of the positioning pins  21   f  and  21   g  against the abutment surfaces, the removed developer accommodating container  21  is positioned to the drum bearing members  22  and  23  with respect to the widthwise and height directions (the arrow Z direction) of the supporting member  15   b . By the above constitution, it is possible to suppress positional deviation due to warpage, bending or the like of the removed developer accommodating container  21 . 
     Since the above constitution is employed, as indicated by an arrow K shown in the B-B cross section of  FIG. 8  (Step  2 ), the removed developer accommodating container  21  is slid and assembled to the supporting member  15   b.    
     After the above-described assembling and positioning are completed, the bearing surface  21   a  of the removed developer accommodating container  21  is, at a longitudinal central portion of the supporting member  15   b , screwed and fixed with a tap tight screw  16   c . At that time, the screw  16   c  is inserted into a hole  15   g  provided in the supporting member  15   b  and then is screwed into a hole  21   b  provided in the bearing surface  21   a . Also in this case, a head shape of the screw  16   c  is not particularly limited. 
     By the above constitution, the removed developer accommodating container  21  can be assembled to the cleaning blade  15  or the photosensitive drum  7  with high accuracy. 
     The cleaning device  11  enclosed by a broken-line portion shown in  FIG. 9  (Step  3 ) has a constitution which best reflects the feature of the present invention. 
     The cleaning device  11  assembled via Steps  1  and  2  includes, as shown in  FIG. 9  (Step  3 ), the drum bearing member (driving side)  22 , the drum bearing member (non-driving side)  23  and gaps a 1 , a 2 , b 1  and b 2  created between the parts of the removed developer accommodating container  21 . As a result, mutual parts are movable with respect to the longitudinal direction (the arrow X direction) of the supporting member  15   b . Thus, the creation of the gaps a 1 , a 2 , b 1  and b 2  is the most characteristic feature of the present invention. 
     By the above constitution, in the cleaning device  11  constituted by the members different in thermal expansion coefficient, even when the change in temperature due to the change in environment occurs and the thermal expansion and contraction amounts of the parts are different from each other, it is possible to absorb the difference in thermal expansion and contraction amount by the gaps a 1 , a 2 , b 1  and b 2 . As a result, stretching stress is not generated between a plurality of parts and therefore it is possible to minimize the fluctuations in penetration amount δ and set angle θ of the cleaning blade  15 , due to the bimetal, which have occurred in the conventional constitution. 
     The supporting member  15   b  to which the present invention is applicable is the zinc-coated steel plate containing iron as the main component and has the thermal expansion coefficient of 1.2×10 −5 /° C. Further, the removed developer accommodating container  21 , the drum bearing member (driving side)  22 , the drum bearing member (non-driving side)  23  and the drum holder  13  which are used in this embodiment to which the present invention is applicable are formed with the PS (polystyrene) resin material having the thermal expansion coefficient of 8.7×10 −5 /° C. 
     Here, the gaps a 1 , a 2 , b 1  and b 2  are, in view of an estimated temperature change in an operational environment, required so that they can sufficiently absorb the differences in contraction amount and expansion amount of the mutual parts. 
     Further,  FIG. 11  shows the driving side of the cleaning device  11  shown in  FIG. 9  (Step  3 ). As shown in  FIG. 11 , an elastic member can be interposed in each of the gaps a 1  and b 1  (a 2  and b 2 ), so that a shock-absorbing effect with respect to the longitudinal direction of the removed developer accommodating container  21  is improved. However, the elastic member  40  is required to have followability such that the elastic member  40  can quickly absorb the difference in thermal expansion and contraction amount generated by the change in environment. For example, it can be considered that rubber is used as the material for the elastic member  40 . The elastic member  40  may preferably be softer than the removed developer accommodating container  21 , the drum bearing member (driving side)  22  and the drum bearing member (non-driving side)  23 . 
     Continuously, in Step  3  ( FIG. 9 ), the assembling of the photosensitive drum  7  is performed. The photosensitive drum  7  is moved downward into the cleaning device  11  and then the drum shaft  14  and the drum holder  13  are engaged with the photosensitive drum  7  and the cleaning device  11  on the driving side and the non-driving side, respectively. 
       FIG. 10  (Step  4 ) shows a state in which the photosensitive drum  7  is assembled to the cleaning device  11  and corresponds to the lower view of  FIG. 6  showing the cleaning device  11  after the assembling. 
     Through the above-described steps, the cleaning blade  15  is accurately contacted to the photosensitive drum  7  with a predetermined penetration amount δ and a set angle θ. Further, as described in Step  3 , the fluctuation in penetration amount due to the bimetal can be minimized. Incidentally, the assembling of the developing unit u is also performed simultaneously with the assembling of the drum holder  13  but is omitted from the description in this embodiment for simplification. 
     Further, the order of Steps  2  and  3  can also be changed (reversed). 
     Further, by forming the removed developer accommodating container  21  and the drum bearing members  22  and  23  of the same material, the expansion and contraction amounts of these parts depending on the temperature change are equal to each other with respect to a widthwise cross-sectional direction (arrow YZ direction) of the supporting member  15   b  of the cleaning blade  15 . As a result, even when the ambient temperature is changed, a positional relationship between the positioning pins (engaging portion)  21   d  and  21   e  ( 21   f  and  21   g ) and the corresponding positioning guides (portion to be engaged)  22   c  and  23   c  ( 22   d  and  23   d ) is maintained in an initially assembled state. For that reason, the bending does not occur, so that it is possible to realize that the positions of the supporting member  15   b  and an elastic blade edge  15   c  ( FIG. 5 ) are not fluctuated and influenced. 
     As described above, according to this embodiment, with respect to the widthwise cross-sectional direction of the supporting member of the cleaning blade, the removed developer accommodating container is provided with the engaging portions and the drum bearing members are provided with the portions to be engaged in order to position the end portions of the removed developer accommodating container to the drum bearing members. As a result, positional stability at the end portions of the removed developer accommodating container in the cleaning device is improved. Further, a degree of the bending occurring when a load or the like is externally exerted on the removed developer accommodating container can be reduced. As described above, the removed developer accommodating container includes the seal member and the sheet member which are configured to collect the removed developer and thus the removed developer accommodating container is stably positioned and supported in the cleaning device to reduce the influence of the bending, so that the leakage of the developer can be prevented. 
     Further, as described above, the drum bearing members are not fixed completely among the mutual parts, so that the mutual parts can move in the longitudinal direction of the supporting member. As a result, even when the cleaning device is constituted by the plurality of parts different in thermal expansion coefficient, the expansion and contraction difference with respect to the longitudinal direction of the supporting member due to the temperature change of the respective parts is absorbed and thus deformation such as warpage of the cleaning blade caused by the bimetal can be minimized. That is, the fluctuations in penetration amount and set angle of the cleaning blade with respect to the photosensitive drum due to the bimetal can be minimized, thus leading to stabilization of a cleaning performance. 
     Further, according to this embodiment, the drum bearing members are separately fixed, as separate members, to the longitudinal end portions of the supporting member of the cleaning blade, so that there is no need to dispose a part of the drum bearing members at a central portion of the supporting member, thus leading to the reduction in use amount of the material to realize cost reduction. 
     Further, when the drum bearing members at the both ends of the supporting member are integrally connected with the supporting member, different from the bimetal between the supporting member and the removed developer accommodating container, new bimetal occurs between the supporting member and the drum bearing members, so that the new bimetal can constitute a fluctuation factor of the cleaning blade. Therefore, the drum bearing members can realize a smaller degree of the fluctuation when they are separately fixed, as separate members, at the both ends of the supporting member, thus leading to the stabilization of the cleaning performance. 
     Further, also with respect to the temperature change in the electrophotographic image forming apparatus, a similar effect can be obtained when the constitution of the present invention is employed. 
     (Embodiment 2) 
       FIG. 14  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to the supporting member  15   b  of the cleaning blade  15  is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     As shown in  FIG. 14 , even in a constitution in which the positioning pins and the positioning guides are eliminated, it is possible to assemble a removed developer accommodating container  30  to the supporting member  15   b  with sufficient supporting strength and the gaps a 1  and a 2  are provided. For that reason, the principal object of the present invention such that the fluctuation of the cleaning blade  15  due to the bimetal is minimized can be accomplished. 
     In Embodiment 1, the principal object of the present invention such that the fluctuation in penetration amount due to the bimetal was minimized was accomplished and in addition, the constitution for further improving the positioning stability at the end portions of the removed developer accommodating container  21  was employed. That is, in Embodiment 1, the constitution in which the removed developer accommodating container  21  was provided with the positioning pins at its end portions and the drum bearing members  22  and  23  were provided with the corresponding positioning guides was proposed. 
     Also in this embodiment, the drum bearing members are fixed at the longitudinal ends of the cleaning blade supporting member and the removed developer accommodating container is fixed at the longitudinal central portion of the cleaning blade supporting member. By fixing the removed developer accommodating container to the supporting member at the longitudinal central portion of the supporting member, supporting stability of the removed developer accommodating container in the cleaning device is improved. The removed developer accommodating container includes the seal member and the sheet member which are configured to collect the removed developer, so that the leakage of the developer can be prevented by the improvement of the supporting stability of the removed developer accommodating container in the cleaning device. 
     (Embodiment 3) 
       FIG. 15  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to the supporting member  15   b  of the cleaning blade  15  is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     In the cleaning device  11  in Embodiment 1 ( FIG. 9 ), the drum bearing member (driving side)  22  and the drum bearing member (non-driving side)  23  are separately constituted. However, as shown in  FIG. 15 , the drum bearing member (driving side)  22  and the drum bearing member (non-driving side)  23  are connected by a connecting portion  28  which is liable to be sufficiently bent and which has low rigidity, and these members  22 ,  23  and  28  may be integrally constituted as a drum bearing member  29 . That is, even when the temperature change occurs in the supporting member  15   b  and the drum bearing member  29  which are members different in thermal expansion coefficient and the mutual parts have different thermal expansion and contract amounts, the connecting portion  28  may only be required to have the low rigidity such that the connecting portion  28  can be bent by absorbing the difference in thermal expansion and contraction amount. 
     Further, also in such a constitution, the gaps a 1 , a 2 , b 1  and b 2  are provided, so that the fluctuations in penetration amount δ and set angle θ due to the bimetal which have been generated in the conventional constitution can be minimized. 
     (Embodiment 4) 
       FIG. 16  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to a supporting member  19   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     In Embodiment 1 ( FIG. 9 ), in order to improve the positioning stability at the end portions of the removed developer accommodating container  21 , the removed developer accommodating container  21  is provided with the positioning pins at its end portions and the drum bearing members  22  and  23  are provided with the corresponding positioning guides. As another constitution for achieving the same effect as that of this constitution, as shown in  FIG. 16 , the supporting member  19   b  is partly bent at its longitudinal end portions to form a bent portion (driving side)  19   c  and a bent portion (non-driving side)  19   d  and then the positioning guides may be provided at the bent portions  19   c  and  19   d.    
     Further, when the constitution in this embodiment is employed, the gaps a 1 , a 2 , b 1  and b 2  are provided and therefore it is possible to accomplish the principal object of the present invention such that the fluctuation in penetration amount of the cleaning blade due to the bimetal is minimized. 
     (Embodiment 5) 
       FIG. 17  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to a supporting member  20   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
       FIG. 17  shows a constitution which is a combination of the constitution in Comparative Embodiment ( FIG. 13 ) and the constitution in Embodiment 1 ( FIG. 9 ). The cleaning blade supporting member  20   b , a removed developer accommodating container  43  and the drum bearing member (driving side)  22  which is used in Embodiment 1 are shown. 
     The fixation between the supporting member  20   b  and the removed developer accommodating container  43  is effected at another end (non-driving side) of the supporting member  20   b  by using the screw  18   b  similarly as in the constitution in Comparative Embodiment. A positioning method of the removed developer accommodating container  43  to the supporting member  20   b  is similar to that in the constitution in Comparative Embodiment. 
     The fixation between the supporting member  20   b  and the drum bearing member (driving side)  22  is effected at one end (driving side) of the supporting member  20   b  by using the screw  16   a  similarly as in Embodiment 1 ( FIG. 9 ). The positioning method of the drum bearing member (driving side)  22  to the supporting member  20   b  is also similar to that in Embodiment 1 ( FIG. 9 ). 
     Further, similarly as in Embodiment 1 ( FIG. 9 ), the removed developer accommodating container  43  is provided with the positioning pin  21   d  ( 21   f ) at its end portion and the drum bearing member (driving side)  22  is provided with the corresponding positioning guide  22   c  ( 22   d ). This is because the positioning stability at the end portions of the removed developer accommodating container  43  in the cleaning device  11  is improved. 
     Further, at the other end (non-driving side), a drum bearing member (non-driving side)  71  is fastened to a side surface of the removed developer accommodating container  43  by using a screw  91 . 
     By the above constitution, in the cleaning device  11  constituted by the members different in thermal expansion coefficient, even when the temperature change occurs due to the change in environment and the mutual parts have different expansion and contraction amounts, the difference in expansion and contraction amount can be absorbed by the gaps a 1  and b 1 . As a result, the fluctuation of the cleaning blade due to the bimetal which has occurred in the conventional constitution can be minimized. Further, at least one of the drum bearing members is fixed at one longitudinal end of the cleaning blade supporting member, and the removed developer accommodating container is fixed at the other longitudinal end of the cleaning blade supporting member. As a result, the fixing portion which was provided at the longitudinal central portion of the supporting member in order to fix the removed developer accommodating container in Embodiment 1 is eliminated, so that the constitution can be simplified. 
     (Embodiment 6) 
       FIG. 18  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to a supporting member  62   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     In  FIG. 18 , the cleaning blade supporting member  62   b , a removed developer accommodating container  44 , the drum bearing member (non-driving side)  23  used in Embodiment 1 ( FIG. 9 ) and a drum bearing member (driving side)  72  are shown. 
     The difference of this embodiment from Embodiment 1 ( FIG. 9 ) is that the removed developer accommodating container  44  is not fixed to the supporting member  62   b  but is fixed to the drum bearing member (driving side)  72  by using the screw  91 . As a result, the gaps a 1  and b 1  at the one end (driving side) are absent but the gaps a 2  and b 2  at the other end (non-driving side) are provided. For that reason, similarly as in Embodiment 1 ( FIG. 9 ), the cleaning blade fluctuation due to the bimetal which has occurred in the constitution in Comparative Embodiment can be minimized. Further, the fixing portion which has been provided at the longitudinal central portion of the supporting member in Embodiment 1 in order to fix the removed developer accommodating container is eliminated, so that the constitution can be simplified. 
     As described above, in the cleaning device constituted by the cleaning blade supporting member and the removed developer accommodating container different in thermal expansion coefficient, in the case where the temperature in the operational environment is changed, the expansion and contraction of the supporting member with respect to the longitudinal direction occurs with a different amount every part. 
     In this embodiment, the removed developer accommodating container and the drum bearing member fixed at the other longitudinal end of the supporting member are not fixed completely among the mutual parts, so that the mutual parts can move in the longitudinal direction of the supporting member. As a result, even when the cleaning device is constituted by the plurality of parts different in thermal expansion coefficient, the expansion and contraction difference with respect to the longitudinal direction of the supporting member due to the temperature change of the respective parts is absorbed and thus deformation such as warpage of the cleaning blade caused by the bimetal can be minimized. That is, the fluctuations in penetration amount and set angle of the cleaning blade with respect to the photosensitive drum due to the bimetal can be minimized, thus leading to stabilization of the cleaning performance. 
     Further, also with respect to the temperature change in the electrophotographic image forming apparatus, a similar effect can be obtained when the constitution of the present invention is employed. 
     (Embodiment 7) 
       FIG. 19  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to the supporting member  20   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     In the cleaning device  11  shown in  FIG. 19 , the removed developer accommodating container  43  and the drum bearing member (non-driving side)  71  in Embodiment 5 ( FIG. 17 ) are integrated with each other and are newly improved and constituted as a removed developer accommodating container  42  also functioning as the drum bearing member (non-driving side). Also in the above constitution, the gaps a 1  and b 1  are provided and thus there is no change in that the cleaning blade fluctuation due to the bimetal which has occurred in the conventional constitution can be minimized. 
     Further, the removed developer accommodating container  42  integrally includes the drum bearing member rotatably supporting the one end of the photosensitive drum  7 , so that the number of parts can be reduced and thus a reduction in cost can be realized. 
     (Embodiment 8) 
       FIG. 20  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to a supporting member  28   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     As in the cleaning device  11  shown in  FIG. 20 , even when the constitution at the one end (driving side) and the constitution at the other end (non-driving side) in Embodiment 7 ( FIG. 19 ) are interchanged, a similar effect can be obtained. Further, also with respect to Embodiment 5 ( FIG. 17 ) and Embodiment 6 ( FIG. 18 ), similarly as with respect to Embodiment 7 and Embodiment 8, it is possible to achieve the similar effect even when the constitution at the one end (driving side) and the constitution at the other end (non-driving side) are interchanged. 
     (Embodiment 9) 
       FIG. 21  shows another cleaning device  11  to which the present invention is applicable in another embodiment and is a sectional view showing the same position as that of the cleaning device  11 , to which the present invention is applicable, shown in  FIG. 9 . An A-A sectional front view obtained by cutting the cleaning device  11  in a plane which passes through the center of the axis of the photosensitive drum  7  and is perpendicular to a supporting member  61   b  of the cleaning blade is illustrated. Only a portion different from Embodiment 1 will be described and a portion which is not particularly described is identical to the corresponding portion in Embodiment 1. 
     In the constitution of Embodiment 1 ( FIG. 9 ), the fixing means for fixing the drum bearing members  22  and  23  to the cleaning blade supporting member  15   b  were the screws. In this embodiment shown in  FIG. 21 , drum bearing members  24  and  25  are not fixed with the screws but are subjected to outsert molding on the supporting member  61   b , thus being formed and fixed at the same time. Further,  FIG. 22  is a perspective view showing an end portion structure of the supporting member  61   b , wherein the supporting member  61   b  is provided with holes  61   e  and  61   f , with respect to the longitudinal direction thereof, in which a molding resin material flows and is positioned so that the molded drum bearing members  24  and  25  are not disconnected. 
     In this embodiment, at the longitudinal end portions of the supporting member  61   b , the drum bearing members  24  and  25  are molded by the outsert molding. Thus, the fastening member such as the screw necessary to connect the drum bearing members  24  and  25  with the supporting member  61   b  is not requires, so that the reduction in the number of parts can be realized. As a result, an assembling property is improved to lead to cost reduction. 
     Further, as shown in  FIG. 5 , the cleaning edge  61   c  of the elastic blade  61   a  or an edge  61   d  of the supporting member  61   b  is used as a positioning reference for the cleaning blade  61  in a metal mold, and the supporting member  61   b  is set in the metal mold for molding the drum bearing members  24  and  25 . Then, the drum bearing members  24  and  25  are subjected to the outsert molding at the both end puritans of the supporting member  61   b . If the latter positioning method of the cleaning blade  61  is used, it is also possible to connect the elastic blade  61   a  with the supporting member  61   b  after the molding of the drum bearing members  24  and  25 . 
     According to these methods, with respect to dimensional accuracy from the cleaning edge  61   c  which is a cleaning function portion (or the reference edge  61   d  of the supporting member  61   b ) to the center of the photosensitive drum  7  disposed between the drum bearing members  24  and  25 , only molding accuracy may be taken into consideration. Thus, the cleaning device can be manufactured in a stable dimension with high precision. As a result, stabilization of the cleaning performance is realized. 
     On the other hand, in the constitution of Comparative Embodiment, the supporting member  17   b  is fixed to the cleaning container  31  with the fastening member such as the screws  18   a  and  18   b  and therefore there is a need to take into consideration dimensional accuracy of each of parts for the cleaning container  31  and the supporting member  17   b  and variation at the time of the assembling ( FIG. 12 ). 
     Further, when the drum bearing members  24  and  25  are subjected to the outsert molding at the both end portions of the supporting member  61   b , the resin material is flowed into the holes of the supporting member  61   b  so as to follow a diesinking shape (shape of the drum bearing members  24  and  25 ) formed at the longitudinal end portions of the supporting member  61   b  in the metal mold. The flowed resin material is contactable to many surfaces of the supporting member  61   b  with a sufficient contact area and thus connecting stability of mutual parts is improved. As a result, the stability of the cleaning performance can be realized. 
     While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth and this application is intended to cover such modifications or changes as may come within the purpose of the improvements or the scope of the following claims. 
     This application claims priority from Japanese Patent Application No. 058416/2010 filed Mar. 15, 2010, which is hereby incorporated by reference.