Patent Publication Number: US-6990302-B2

Title: Process cartridge and electrophotographic image forming apparatus regulating the positions of creases on a flexible member in accordance with pivotal movement of a support member

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a process cartridge detachably attachable to an electrophotographic image forming apparatus body, and an electrophotographic image forming apparatus to and from which the process cartridge can be attached and detached. 
   The electrophotographic image forming apparatus referred to above is an apparatus for forming an image on a recording medium by using an electrophotographic image forming system. Such electrophotographic image forming apparatuses include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer and a LED printer), facsimile machine, and a word processor. 
   The process cartridge mentioned above is formed by combining at least one of a charging means, a developing means and a cleaning means as a process means with an electrophotographic photosensitive member in one body into a cartridge. This cartridge is formed so that the cartridge can be attached to and detached from an image forming apparatus body. 
   2. Description of the Related Art 
   A process cartridge system has heretofore been employed which is formed by putting together an electrophotographic photosensitive member and a charging means, a developing means and a cleaning means in one body into a cartridge, and fixing this cartridge to an image forming apparatus body so that the cartridge be detachably attachable to the apparatus body. This cartridge system enables the operability of the apparatus to be further improved, and a user to carry out the maintenance of the above-mentioned process means easily. Therefore, this cartridge system is used widely in an image forming apparatus body. 
   When the process cartridge in such a cartridge system is provided on an outer side of the image forming apparatus body, it is necessary that the electrophotographic photosensitive member (which will hereinafter be referred to as a photosensitive drum) be not exposed to the light. It is also necessary to prevent a user from directly contacting the photosensitive drum to cause an imperfect image to be formed. Therefore, light shielding shutters for covering the photosensitive drum therewith are used. These shutters are made of rigid parts formed out of mainly a resin in many cases. 
   However, since the shutters are made of rigid members, a space for providing a path along which the shutters are opened and closed, and for storing the shutters is needed. 
   Under the circumstances, shutters made of a flexible film sheet so as to reduce the space for storing the shutters therein have been devised (refer to, for example, JP-A-2001-282078). 
   Also, shutters formed by providing a plurality of reinforcement members on flexible sheet members so that the resultant products can be folded like bellows in the longitudinal direction and stored in such a space have been devised (refer to, for example, JP-A-62-278575). 
   Shutter structures formed out of a flexible material so as to reduce a shutter storage space, and wound up during the use of the shutters to cause a photosensitive drum to be exposed have also been devised (refer to, for example, U.S. Pat. No. 5,231,453). 
   Shutter structures formed by joining thin, narrow plates together by hinges are drawn into a predetermined storage portion of a process cartridge have also been devised (refer to, for example, U.S. Pat. No. 6,091,916). 
   The present invention has been attained on the basis of the above-described related techniques by making further improvements thereon. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to provide a process cartridge capable of protecting an electrophotographic photosensitive member by a simple structure, and an electrophotographic image forming apparatus using the same cartridge. 
   Another object of the invention is to provide a space-saving process cartridge, and an electrophotographic image forming apparatus using the same cartridge. 
   Another object of the invention is to provide a simply constructed process cartridge, and an electrophotographic image forming apparatus using the same cartridge. 
   Another object of the invention is to provide a process cartridge adapted to prevent a large deflection of a flexible member and move the flexible member smoothly to a retraction position, and an electrophotographic image forming apparatus using the same cartridge. 
   Another object of the invention is to provide a process cartridge having a regulating member on the flexible member for the purpose of regulating positions of creases which occur on the flexible member in accordance with a pivotal movement of a support member, and which extend in parallel with the longitudinal direction (or the axis of rotation) of an electrophotographic photosensitive member; and capable of having the flexible members being able to be folded on the creases and moved to positions of retraction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a first embodiment of the process cartridge according to the present invention; 
       FIG. 2  is a schematic sectional view of the first embodiment of an image forming apparatus according to the present invention; 
       FIG. 3  is a sectional view showing the condition of attaching and detaching the first embodiment of the process cartridge according to the present invention to an apparatus body; 
       FIG. 4A  is a perspective view showing the condition in which the first embodiment of the process cartridge according to the present invention is fixed to a cartridge storage guide; 
       FIG. 4B  is a schematic view for describing a mechanism of opening a shutter of a photosensitive drum when the cartridge storage guide is inserted into the image forming apparatus; 
       FIG. 5  is a schematic sectional view showing the condition of the storing of the drum shutter in the first embodiment of the present invention; 
       FIG. 6  is a perspective view of a second embodiment of the process cartridge according to the present invention; 
       FIG. 7  is a schematic sectional view showing the condition of the storing of the drum shutter in the second embodiment of the present invention; 
       FIG. 8  is a schematic sectional view showing the condition of the storing of the drum shutter on the assumption that a regulating member is not provided, so as to describe the effect of the embodiment of the present invention; 
       FIG. 9  is a schematic sectional view showing the condition of the storing of the drum shutter on the assumption that a rigid drum shutter is provided, so as to describe the effect of the embodiment of the present invention; and 
       FIG. 10  is a schematic sectional view showing the condition of the storing of the drum shutter on the assumption that a regulating member is not provided, so as to describe the effect of the second embodiment of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred modes of embodiments of the present invention will now be described illustratively with reference to the drawings. The size, material, shape and the relative arrangement of the constituent parts described in these modes of embodiments do not signify that the scope of the invention is limited thereto unless any specific description thereof is given. The material and shape, which will once be described in the following statement, of members are identical with those of the same members as are described first unless any special description thereof will be newly given. 
   (First Embodiment) 
   [Description of the Electrophotographic Image Forming Apparatus As a Whole] 
   First, the general construction of the electrophotographic image forming apparatus (which will hereinafter be referred to as an “image forming apparatus”) will be described with reference to  FIG. 2 .  FIG. 2  is a schematic sectional view of a first embodiment of the image forming apparatus according to the present invention. To be more concrete, the drawing is an explanatory drawing of the general construction of a color laser beam printer constituting a mode of a color image forming apparatus. 
   As shown in  FIG. 2 , an image forming apparatus  300  (color laser beam printer) has a process cartridge  2  ( 2 Y,  2 M,  2 C, and  2 Bk) fixed thereto. The cartridge  2  has an electrophotographic sensitive member (which will hereinafter be referred to as a “photosensitive drum”)  21  ( 21 Y,  21 M,  21 C, and  21 Bk) rotated at a predetermined speed for each of various colors Y, M, C and Bk. The image forming apparatus also has an intermediate transfer member  35 . The intermediate transfer member  35  is a part for retaining a color image thereon which is developed in the cartridge  2  and multiplexly-transferred to the intermediate transfer member, and further transferring the same image to a recording medium P sent from a feed unit. The image forming apparatus  300  further has a fixing unit  50  for fixing the color image on a color image-transferred recording medium P, and discharge roller pairs  53 ,  54 , and  55  for discharging the recording medium P onto a discharge tray  56  provided on an upper surface of the apparatus. The above-mentioned cartridges  2 Y,  2 M,  2 C, and  2 Bk for images of four colors are formed so that the cartridges can be separately attached to and detached from the main body of an image forming apparatus. 
   The construction of each unit of the image forming apparatus  300  will now be described. 
   [Electrophotographic Photosensitive Member] 
   The photosensitive drum  21  ( 21 Y,  21 M,  21 C, and  21 Bk) constituting an electrophotographic photosensitive member is formed by applying a layer of an organic photo conductor to an outer circumferential surface of an aluminum cylinder. The photosensitive drum  21  is supported rotatably in a container  24  ( 24 Y,  24 M,  24 C, and  24 Bk). A driving force of a driving motor (not shown) is transmitted to one end of the photosensitive drum  21 . This causes photosensitive drum  21  to be rotated in accordance with an image forming operation. 
   [Charging Means] 
   The charging means uses a contact charging system, in which a conductive charging roller  23  ( 23 Y,  23 M,  23 C, and  23 Bk) formed in the shape of a roller is brought into contact with a surface of the photosensitive drum  21 . Simultaneously with the charging roller engaging operation, the surface of the photosensitive drum  21  is charged uniformly by applying a voltage to the charging roller  23  ( 23 Y,  23 M,  23 C, and  23 Bk). 
   [Exposure Means] 
   A scanner unit  1  exposes the photosensitive drum  21 . An image signal is given to a laser diode. This laser diode applies image forming light ( 10 Y,  10 M,  10 C, and  10 Bk) corresponding to the image signal to a polygon mirror ( 11 Y,  11 M,  11 C, and  11 Bk). This polygon mirror is rotated at a high speed by a scanner motor. The image light reflected on the polygon mirror exposes the surface of the photosensitive drum  21  selectively which is rotated at a predetermined speed via an image forming lens ( 13 Y,  13 M,  13 C, and  13 Bk). As a result, an electrostatic latent image is formed on the photosensitive drum  21 . 
   [Developing Means] 
   A developing means develops the electrostatic latent image into a visible image. For this purpose, the developing means is formed by four development units capable of developing images of each of the colors including yellow, magenta, cyan, and black. Each development unit ( 222 Y,  222 M,  222 C, and  222 Bk) for images of four colors is opposed to the photosensitive drum  21  and disposed in a position in which a developing roller  22  ( 22 Y,  22 M,  22 C, and  22 Bk) contacts the photosensitive drum  21  as the roller is rotated. A visible image made of a toner of each color is then formed on the photosensitive drum  21 . 
   [Intermediate Transfer Member] 
   An intermediate transfer member  35  multiplexly transfers thereto during a color image forming operation a toner image made visible by each cartridge  2  ( 2 Y,  2 M,  2 C, and  2 Bk) and formed on the photosensitive drum  21 . For this purpose, the intermediate transfer member is rotated clockwise on the drawing and synchronously with a peripheral speed of the drum  21  of a photosensitive material  21 . The toner image formed on the photosensitive drum  21  is multiplexly transferred onto the intermediate transfer member  35  in a primary transfer section, which constitutes a contact point with respect to a voltage-applied primary transfer roller ( 34 Y,  34 M,  34 C, and  34 Bk) disposed in a position opposed to the photosensitive drum  21  with the intermediate transfer member  35  held therebetween. 
   The intermediate transfer member  35  to which the toner image was multiplexly transferred is sent forward in a secondary transfer area T 2  with the recording medium P held between a voltage-applied transfer roller  51  and drum  21  of photosensitive member, and thereby simultaneously and multiplexly transfers the toner images of various colors on the intermediate transfer member  35  onto the recording medium P. 
   [Feed Unit] 
   A feed unit feeds a recording medium (for example, recording paper and OHP sheet) P to the image forming unit. The feed unit has mainly a feed cassette  7  in which a plurality of sheets of recording media P are stored, a feed roller  41 , a separating pad  42 , a feed guide  43  and a resist roller pair  44 . During an image forming operation, the feed roller  41  is driven and rotated in accordance with an image forming action, and feeds the recording media P in the feed cassette  7  while separating the recording media P sheet by sheet. At the same time, the recording media are guided by the feed guide  43  and reach the resist roller pair  44  via transfer rollers. 
   During the image forming operation, the resist roller pair  44  carry out in a predetermined sequence a non-rotational operation for stopping on standby the recording medium P and a rotational operation for transferring the recording medium P toward the intermediate transfer member  35 . The aligning of the image used in a transfer step, a subsequent step with the recording medium P is then done. 
   [Transfer Unit] 
   A transfer unit includes a transfer roller  51 . In this stage of the image forming operation, the intermediate transfer member  35  and transfer roller  51  are driven respectively. Therefore, the recording medium P held between these rollers is subjected to a transfer step, and, at the same time, transferred (in the leftward direction of the drawing) at a predetermined speed. The recording medium P is then transferred toward a fixing unit  50  in which a subsequent step is carried out. 
   [Fixing Unit] 
   The fixing unit  50  is a unit for fixing the toner image formed on the recording medium P by the developing unit via the intermediate transfer member  35 . The fixing unit  50  has a film guide unit  61  in which a ceramic heater  63  for applying heat to the recording medium P is contained, and a pressure roller  62  for bringing the recording medium P into pressure contact with the film guide unit  61 . That is, the toner image-retaining recording medium P is transferred by the film guide unit  61  and pressure roller  62 , and the toner image is fixed on the recording medium P owing to the heat and pressure applied to the recording medium P. 
   [Image Forming Operation] 
   An operation in a case where the formation of an image is carried out by the apparatus constructed as described above will now be described. 
   First, the feed roller  41  shown in  FIG. 2  is rotated, and one piece of recording medium P in the feed cassette  7  is separated and transferred to the resist roller pair  44 . 
   On the hand, the photosensitive drum  21  and intermediate transfer member  35  are rotated at respective predetermined peripheral speeds V (which will hereinafter be referred to as process speeds) in the direction of an arrow in the drawing. 
   The photosensitive drum  21  the surface of which was charged uniformly by the charging unit  23  receives the image forming light  10 , and carries out the formation of an image. 
   Since the operations for forming images of various colors are identical, the formation of a yellow image will be described in the following paragraphs. 
   The irradiation of the yellow image forming light is conducted by the scanner unit to form a yellow latent image on the photosensitive drum  21 Y. Simultaneously with the formation of this latent image, the yellow image developing roller  22 Y is driven, and the developing of the yellow image is done by applying to the photosensitive drum  21 Y a voltage the polarity and potential of which are substantially identical with those of the photosensitive drum  21 Y so that the yellow toner is deposited on the latent image on the same drum. At the same time, the yellow toner image on the photosensitive drum  21 Y is primarily transferred to an outer circumference of the intermediate transfer member  35  in a primary transfer area T 1 Y provided on the downstream side of the developing area. During this time, the primary transfer of the toner image is carried out with a voltage the characteristics of which are contrary to those of the yellow toner applied to the intermediate transfer member  35 . 
   Magenta, cyan and black images are formed in the same manner as mentioned above. The formation of latent images, the development thereof and the transfer of toner to the intermediate transfer member  35  of the yellow, magenta, cyan and black images are carried out in the mentioned order of colors in the respective primary transfer positions. As a result, a full-color image made of four kinds of toners including yellow, magenta, cyan and black toners is formed on the surface of the intermediate transfer member  35 . 
   Before a front end of the full-color image, which was formed on the intermediate transfer member  35  after the primary transfer of the black toner, a fourth color toner had finished, the recording medium P stopped on standby at the previously-mentioned resist roller pair  44  is sent out at suitable timing. 
   When the images of the four colors are formed on the intermediate transfer member  35 , the transfer roller  51  stopped on standby in a lower position and not in contact with the intermediate transfer member  35  is moved up at the same time by a cam (not shown), and the recording medium P is brought into pressure contact with the intermediate transfer member  35  in a secondary transfer area T 2 . Simultaneously with this operation, a bias voltage the characteristics of which are contrary to those of the toner is applied to the transfer roller  35 . 
   Thus, a full-color image having four colors on the intermediate transfer member  35  is transferred at a time onto the recording medium P. 
   The recording medium P passing through the secondary transfer area T 2  is peeled off from the intermediate transfer member  35 , transferred to the fixing unit and subjected to a toner fixing operation. The recording medium P is then discharged with an image surface directed downward onto the discharge tray  56  via the discharge rollers  53 ,  54 , and  55  to finish the image forming operation. 
   [Attaching and Detaching of the Process Cartridge] 
   A method of attaching and detaching the cartridge  2  to and from the main body of the apparatus will now be described with reference to  FIG. 3 .  FIG. 3  is a sectional view showing the condition of attaching and detaching the cartridge  2  of the second embodiment of the present invention to and from the main body of the image forming apparatus. 
   A front cover  14 , which is fixed to a unit in one body which unit includes the intermediate transfer member  35 , for the apparatus body is opened rightward (in the frontward direction of the apparatus body). As a result, a cartridge storage guide  101  holding four cartridges  2  therein is exposed. As a result, the cartridge storage guide is inclined at an angle of about 35° around a center  101   a  of a pivotal movement thereof. This enables the operations for attaching and detaching the cartridge  2  to and from the main body of the apparatus to be carried out. 
     FIG. 4A  is a perspective view showing the condition of the cartridge  2  fixed to the cartridge storage guide. 
   The cartridge  2  is inserted with the cartridge retained in the cartridge storage guide  101  into the main body of the image forming apparatus with the center  101   a  of a pivotal movement of the guide  101  positioned in the center of the main body of the apparatus. The cartridge is finally fixed to a mount  200 . The position of the cartridge is determined by a cartridge support member  102 , which is combined with a left side plate  100  of the apparatus body, and a photosensitive drum coupling (not shown). 
   [Construction of Protective Member for Electrophotographic Photosensitive Member] 
   The construction of a protective member (drum shutter) for the photosensitive drum in the first embodiment will now be described with reference to  FIG. 1 .  FIG. 1  is a perspective view of the first embodiment of the process cartridge according to the present invention. 
   A drum shutter  29  provided on this embodiment of the cartridge  2  has a pivotable rod type support member  25  on a flexible member  26 . A regulating member  27  for regulating a crease of the flexible member  26  is fixed to the same member  26 . 
   In this embodiment, a flexible member  26  of a thickness of up to around 20 μm to 500 μm can be used. The thickness may be selected from levels in the range which does not spoil the storing ability, which will be described later, of the flexible member. In short, a flexible material may be used for this member even when the thickness thereof is large, and, when fiber (cloth) having a flexibility is used, the thickness thereof can be set to even not smaller than 1 mm. 
   The flexible member  26  in the first embodiment uses a PE (polyethylene) film of around 100 μm in thickness. 
   In this embodiment, other materials, such as PP (polypropylene) and an elastomer-based film can also be suitably selected. 
   In order to shield the photosensitive drum  21  from the light, the flexible member  26  in the first embodiment is colored black. Besides such a colored flexible member  26 , a carbon-containing conductive film (having, for example, a surface resistance value of not higher than 10 10  Ω/square) can also be used. The aforementioned structure improves light shielding ability, so that damage to the photosensitive drum  21  can be prevented, and, moreover, the flexible member  26  turns into a conductive film owing to the carbon contained therein. This enables the charging of a memory with static electricity to be prevented. 
   The regulating member  27  in this embodiment is made of a plate type reinforcing member the material of which is more rigid than that of the flexible member  26 , and fixed on the flexible member  26 . The fixing method for the regulating member may be any one of the methods using an adhesive double-coated tape, a bonding agent and heat sealing techniques. In the first embodiment, a PET (polyethylene terephthalate) sheet of around 100 μm in thickness is pasted on the flexible member  26 . 
   The regulating member  27  may be used not as a reinforcing member but as a member on which letters are printed, or on which colored letters are shown, for the purpose of having a user know a position in which each cartridge should be fixed. Owing to this structure, the user&#39;s visibility of the parts is heightened, and the controllability of the cartridge  2  during an operation for fixing the cartridge to the main body of the image forming apparatus  300  is improved. Moreover, fixing a cartridge of a different color erroneously to the main body of the apparatus can be prevented. 
   Although the regulating member  27  is provided on an outer surface of the flexible member  26  in the first embodiment, the regulating member may also be provided on both the outer and inner surfaces thereof. The regulating member  27  may also be provided on the inner surface (the surface facing the electrophotographic photosensitive member) only. In this case, however, a material which does not damage the surface of the electrophotographic photosensitive member, and a material which does not generate an electrostatic memory on the electrophotographic photosensitive member may be selected as the material used on the inner surface of the flexible member. 
   [Opening and Closing of the Protective Member for the Electrophotographic Photosensitive Member] 
   The drum shutter storing condition will now be described with comparative reference to  FIGS. 4B ,  5 ,  8  and  9 .  FIG. 4B  is a schematic sectional view showing a structure for opening the shutter for the photosensitive drum when the cartridge storage guide is inserted into the image forming apparatus.  FIG. 5  is a schematic sectional view showing the condition of the drum shutter provided in the first embodiment of the present invention.  FIG. 8  is a schematic sectional view showing the condition of the storing of the drum shutter on the assumption that the regulating member is not provided thereon, so as to describe the effect of the first embodiment of the present invention.  FIG. 9  is a schematic sectional view showing the condition of the storing of the drum shutter on the assumption that the drum shaft is made of a rigid member, so as to describe the effect of the first embodiment of the present invention. As described above, the embodiments shown in  FIGS. 8 and 9  are made assumptively so as to describe the effects of the embodiments of the present invention easily understandably, and were not known at the time of filing the patent application of the invention. 
   As shown in  FIG. 4B , the cartridge  2  is inserted into the main body of the image forming apparatus with the cartridge retained in the cartridge storage guide  101 . As a result, a support member  25  engages a projection  102   a  as a moving member extending from a cartridge support member  102 . When the cartridge storage guide  101  is further turned to cause the cartridge  2  to be moved to a deep portion of the main body of the image forming apparatus, the support member  25  is pushed in the direction of an arrow X in  FIG. 1 . As a result, the shutter  29  of the photosensitive drum  21  provided on the cartridge  2  is opened. 
   That is, the support member  25  engages the projection  102   a  in accordance with an operation for fixing the cartridge  2  to the mount  200 . As a result, the support member  25  is moved just as the flexible member  26  which moves from a protection position to a retraction position. 
   The action (opening action) of the shutter  29  in the first embodiment will now be described. 
   First, the support member  25  makes a rotational movement from the condition ( FIG. 5A ) in which the shutter  29  of the photosensitive drum  21  covers the same drum. The flexible member  26  is supported at one side  26   a  thereof on a support portion  25   a  of the support member  25 , and at the other side  26   b  thereof on a support portion  2   a  of the main body of the cartridge  2 . In the condition in which the flexible member  26  covers the photosensitive drum  21 , the flexible member  26  is bent to an outer side of the cartridge  2  so that the flexible member does not contact the photosensitive drum  21 . 
   When the rotational movement of the support member is started, a crease  26 Q occurs ( FIG. 5B ) first in a region between the regulating member  27  and the support portion  25   a  of the film support member  25  on which the first-mentioned side  26   a  of the flexible member  26  is supported. The reason resides in that the rigidity of a region made of the flexible member  26  only is lower than that of a region in which the regulating member  27  is provided. This causes a crease to occur selectively even when the same level of force is exerted on each region. Therefore, when the regulating member  27  is provided, the crease on the flexible member  26  is fixed, or the curvature of a crease on a film can be freely set. In addition, the operations for opening and closing the shutter  29  come to be carried out more certainly, and the reliability of such operations becomes high. 
   In the condition in which the flexible member  26  covers the photosensitive drum  21  as mentioned above, the flexible member  26  is bent to the outer side of the cartridge  2  so that the flexible member  26  does not contact the photosensitive drum  21 . Therefore, the crease  26 Q always occurs on the inner side of the flexible member  26 . Accordingly, when the support member  25  further continues to be turned, the support portion  25   a  thereof passes ( FIG. 5C ) through the region between the regulating member  27  and the photosensitive drum  21 . 
   At nearly this time, a new crease  26 R occurs ( FIG. 5D  in a region between the regulating member  27  and the support portion  2   a  at which the cartridge  2  supports the second-mentioned side  26   b  of the flexible member  26 . 
   When the support member  25  further continues to be turned, the regulating member  27  continues to retract leftward (to the rear side of the cartridge) in the drawing up to a final storage position ( FIG. 5E ). 
   During this time, the regulating member  27  is folded back owing to the upward movement in the drawing of the first-mentioned side  26   a  of the flexible member  26 , which is supported on the support member  25 , from the second-mentioned side  26   b  thereof supported on the cartridge  2 . As a result, the flexible member  26  is folded in the direction crossing the longitudinal direction (or the axis of rotation) of the photosensitive drum  21 . This enables the shutter  29  to be compactly folded. A space for storing the drum shutter does not need to be secured widely unlike the similar space in the related art apparatus, so that a high-degree space-saving can be attained. 
   The flexible member  26  has the first crease  26 Q occurring in such a region in accordance with the pivotal movement of the support member  25  that is between the regulating member  27  and support portion  25   a  at which the support member  25  supports the flexible member  26  thereon. Moreover, the flexible member  26  has the second crease  26 R occurring in such a region in accordance with the further pivotal movement of the support member  25  that is between the regulating member  27  and support portion  2   a  at which the cartridge  2  supports the flexible member  26 . This enables the shutter  29  to be folded more compactly as compared with the shutter having one crease. 
   When the regulating member  27  is used as described above, the shutter can be set so that the creases are generated in desired positions, by simply constructed, small number of parts, and the manufacturing cost can be advantageously reduced. 
   Furthermore, when the regulating member  27  is provided, a planar portion is formed, so that the slackening of the flexible member  26  is prevented. That is, the flexible member  26  does not contact the photosensitive drum  21 , so that the hurting of the photosensitive drum  21  can be prevented. Moreover, the protecting performance of the flexible member with respect to the photosensitive drum  21  is high as compared with a flexible member having a flexible film only thereon. 
   The order of generating the creases, the number of the creases and the size thereof can be changed by varying the position in which the regulating member is pasted on the flexible member, the number of the regulating member fixed to the flexible member, the material of which the flexible film is made, a path along which the film support member is moved. The first embodiment showed one example of these methods. 
   A drum shutter closing operation is substantially contrary to the above-described drum shutter opening operation. As described above, when, for example, the paths of the support member  25  for supporting the flexible member are set different in the shutter opening and closing operations, the same operations can be set separately. 
   According to the construction of the first embodiment, the flexible member can carry out a predetermined deformation operation repeatedly in accordance with the pivotal movement of the support member while attaining the saving of a space, in such a manner that the flexible member does not interfere with the electrophotographic photosensitive member. That is, a large deflection of the flexible member is prevented by regulating the positions of creases occurring on the flexible member by the regulating member provided thereon. At the same time, the flexible member can be folded in a retraction position thereof in a space-saving manner. 
   For example, a mode of embodiment in which a drum shutter  30  is stored with a regulating member  27  not provided as shown in  FIG. 8  is supposed. In this embodiment, a crease  150 Q having a large radius of curvature is formed in a flexible member  150  to occupy a useless space. In this case, the crease  150 Q occurring in accordance with the pivotal movement of a support member  151  necessarily contacts an intermediate transfer member  35  ( FIG. 8E ). The crease  150 Q is formed in the position shown in the drawing, and, in some other cases, at the opposite side thereof, in which case a space on the side of an upper surface of the cartridge  3  is wasted. 
   As shown in  FIG. 9 , a mode of embodiment in which a drum shutter  28  of a rigid material is stored is supposed. In such a case, the necessity of securing a sufficient space around a path along which the shutter  28  moves occurs in some cases when the shutter makes its opening action. For example, it is necessary to secure a space of a size H shown in the drawing, in the direction the height, and a space of a size W shown in the drawing, in the substantially horizontal direction. Therefore, the cartridge  4  cannot attain the saving of a space therefor, and the dimensions of an image forming apparatus to and from which the cartridge  4  can be attached and detached increase in some cases. 
   For these reasons, the previously-described effects of the first embodiment cannot be obtained in the structures described with reference to  FIGS. 8 and 9 . 
   (Second Embodiment) 
   A second embodiment of the present invention will be described with reference to  FIGS. 6 ,  7  and  10 . The structures in this embodiment which are identical with or corresponding to those in the first embodiment will be designated by the same reference numerals, and a detailed description thereof will be omitted. Since the construction of the second embodiment of the image forming apparatus and a principal portion of a process cartridge thereof is identical with that of those of the first embodiment, the characteristic portions only of the second embodiment of the process cartridge will be described. 
     FIG. 6  is a perspective view of the second embodiment of the process cartridge according to the present invention.  FIG. 7  is a schematic sectional view showing the condition of a stored drum shutter in the second embodiment according to the present invention.  FIG. 10  is a schematic sectional view showing the condition of a stored drum shutter supposed with a regulating member not provided, so as to describe the effect of the second embodiment of the present invention. As mentioned previously, the embodiment shown in  FIG. 10  is supposed so as to describe the effect of the embodiment of the present invention easily understandably, and was not known at the time of filing of the patent application of the invention. 
   A cartridge  2  of the second embodiment shown in  FIG. 6  is provided with a flexible handle  20 . This handle  20  is provided so that a user attaches and detaches the cartridge  2  to and from the main body of the image forming apparatus with an improved controllability. The handle  20  is provided so as to project from the cartridge  2  toward the side of an intermediate transfer member  35  so that the cartridge can be held easily. 
   When the handle  20  is provided in the above-mentioned manner, the easiness of holding the cartridge is improved. However, when the handle is left as it is, the handle has a fear of interfering with the intermediate transfer member  35  when the cartridge  2  is fixed to the image forming apparatus. Therefore, when the handle  20  can retract in accordance with an opening action of a shutter  29 , an excessive operation does not need to be carried out, so that the cartridge fixing operation can be executed conveniently. 
   Therefore, the shutter  29  in the second embodiment is brought into contact with the handle  20  as shown in  FIG. 7 , to cause the handle  20  to be deformed in the upward direction and put in a retracted state. A structure capable of retracting the handle  20  in this manner without needing any excessive operation is employed. An action (opening action) of the shutter  29  in the second embodiment will now be concretely described. 
   First, a support member  25  starts being turned from the condition ( FIG. 7A ) in which a shutter  29  covers the photosensitive drum  21 . In this condition, a flexible member  26  is supported at its one side  26   a  on a support portion  25   a  of the support member  25 , and at the other side  26   b  thereof on a support portion  2   a  of a main body of a cartridge  2 . In the condition in which the flexible member  26  covers the photosensitive drum  21 , the flexible member  26  is bent to an outer side of the cartridge  2  so as not to contact the photosensitive drum  21 . 
   When the rotational movement of the support member  25  is started, a crease  26 Q occurs ( FIG. 7B ) first in a region between a regulating member  27  and the support portion  25   a  of a film support member on which the first-mentioned side  26   a  of the flexible member  26  is supported. The reason why the crease occurs reside in that the rigidity of the region in which the flexible member  26  only exists is lower than that of the region in which the regulating member  27  is provided. Therefore, the crease occurs selectively even when the same level of force is exerted on each region. 
   In the condition in which the flexible member  26  covers the photosensitive drum  21 , the flexible member  26  is bent in the outer side of the cartridge  2  so as not to contact the photosensitive drum  21  as mentioned above. Therefore, the crease  26 Q always occurs on the inner side of the flexible member  26 . As a result, when the support member  25  further continues to be turned, the support portion  25   a  of the support member  25  passes ( FIG. 7C ) through a region between the regulating member  27  and the photosensitive drum  21 . 
   At around this time, a new crease  26 R occurs ( FIG. 7D ) in a region between the regulating member  27  and a support portion  2   a  on which the cartridge  2  supports the second-mentioned side  26   b  of the flexible member  26 . 
   When the support member  25  further continues to be turned, the regulating member  27  continues to retract leftward (toward the rear-side of the cartridge) in the drawing up to a final storage position ( FIG. 7E ). 
   During this time, the pivotal movement of the support member  25  causes the first-mentioned side  26   a  of the flexible member  26  supported on the support member  25  to be moved to a position higher than that of the second-mentioned side  26   b  thereof supported on the cartridge  2 . As a result, the regulating member  27  is folded back, and raises the handle  20  in the upward direction in the drawing ( FIG. 7E ). 
   Consequently, the handle  20  retracts from the intermediate transfer member  35 . As a result, the interfering of the handle  20  and intermediate transfer member  35  with each other can be prevented simply without needing the user&#39;s special operation. 
   According to the second embodiment, the interfering of the handle  20  and intermediate transfer member  35  with each other can be prevented simply in addition to such an effect as is possessed by the above-described first embodiment. 
   As shown in  FIGS. 10A to 10E , a mode of embodiment in which a shutter  30  not provided with a regulating member  27  is stored in a process cartridge is now supposed. In this case, it is conceived that a crease  150 Q of a large radius of curvature is formed. As a result, the flexible member  150  does not contact the handle  20  and occupies a useless space, so that the flexible member  150  contacts ( FIG. 10E ) the intermediate transfer member  35 . It is conceived that the crease  150 Q is formed on the opposite side in some cases which is other than the position shown in the drawing. In this case, a useless space occurs on the side of an upper surface of a cartridge  5 . 
   For these reasons, the previously-described effects of the second embodiment cannot be obtained in the structures described with reference to  FIG. 10 . 
   The above-described embodiments of the present invention are as follows. 
   A process cartridge  2  detachably attachable to a main body of an electrophotographic image forming apparatus, provided with: 
   an electrophotographic photosensitive drum  21  on which an electrostatic latent image is formed, 
   process means (for example, a developing roller  22  and a charging roller  23 ) working on the electrophotographic photosensitive drum  21 , 
   a flexible member  26  for protecting the electrophotographic photosensitive drum  21  capable of taking a protection position in which the flexible member protects the same drum  21 , and a retraction position in which the flexible member retracts from the protection position, 
   a support member  25  which has a support portion  25   a  on which the flexible member  26  is supported, and which is provided pivotably on a frame of the cartridge  2 , which support member  25  is adapted to move the flexible member  26  from the protection position to the retraction position, and 
   a regulating member  27  provided on the flexible member  26  so as to regulate the positions of creases  26 Q,  26 R occurring on the flexible member  26  in accordance with a pivotal movement of the support member  25  and extending in parallel with the longitudinal direction (or the axis of rotation) of the electrophotographic photosensitive drum  21 , 
   the flexible member  26  being folded on the creases  26 Q,  26 R and moved to the retraction position. 
   In the condition in which the flexible member  26  is in the protection position, the flexible member  26  is bent to an outer side of the cartridge  2  so that the flexible member does not contact the electrophotographic photosensitive drum  21 , 
   the support portion  25   a  passing through a region between the regulating member  27  and electrophotographic photosensitive member  21  in accordance with the pivotal movement of the support member  25 . 
   The flexible member  26  has: 
   a first crease  26 Q occurring in a region between the regulating member  27  and support portion  25   a , at which the flexible member support member  25  supports the flexible member  26 , in accordance with the pivotal movement of the support member  25 , and 
   a second crease  26 R occurring in a region between the regulating member  27  and support portion  2   a , at which the process cartridge  2  supports the flexible member  26 , in accordance with a further pivotal movement of the support member  25 . 
   The cartridge  2  is provided with a handle  20  used when the cartridge  2  is attached to and detached from the main body of the apparatus, 
   the regulating member  27  contacting the handle  20  when the flexible member  26  is folded in accordance with the pivotal movement of the support member  25 , the handle  20  being thereby retracted to the retraction position. 
   The rigidity of the regulating member  27  is higher than that of the flexible member  26 . 
   The regulating member  27  is a plate type regulating member  27  fixed to the flexible member  26 . 
   The regulating member  27  is integrally molded with the same material as the flexible member, the thickness of the portion of the flexible member  26  which is not provided with the regulating member  27  being larger than that of the portion thereof which is provided with the regulating member  27 . 
   An electrophotographic image forming apparatus  300 , to and from which the process cartridge  2  can be attached and detached, adapted to be used to form an image on a recording medium P, provided with: 
   (i) an electrophotographic photosensitive drum  21  on which an electrostatic latent image is formed, 
   process means (for example, a developing roller  22  and a charging roller  23 ) working on the electrophotographic photosensitive drum  21 , 
   a flexible member  26  protecting the electrophotographic photosensitive drum  21 , and capable of taking a protection position in which the flexible member protects the electrophotographic photosensitive drum  21 , and a retraction position in which the flexible member retracts from the protection position, 
   a support member  25  having a support portion  25   a  on which the flexible member  26  is supported, provided pivotably on a frame of the cartridge  2 , and adapted to move the flexible member  26  from the protection position to the retraction position, and 
   a regulating member  27  provided on the flexible member  26  so as to regulate the positions of the creases  26 Q and  26 R which occur on the flexible member  26  in accordance with the pivotal movement of the support member  25 , and which extend in parallel with the longitudinal direction (or the axis of rotation) of the electrophotographic photosensitive drum  21 , 
   the apparatus  300  having a mount  200  for fixing thereto detachably the process cartridge  2  in which the flexible member  26  is folded on the creases  26 Q and  26 R and moved to the retraction position, 
   (ii) moving means (projection  102   a ) adapted to move the support member  25  so that the flexible member  26  is moved to the retraction position in accordance with an action of fixing the process cartridge  2  to the mount  200 , and 
   (iii) conveying means for conveying the recording medium P. 
   As described above, the present invention can provide a process cartridge of a simple construction in a space-saving manner, capable of protecting an electrophotographic photosensitive drum; and an electrophotographic image forming apparatus using the same process cartridge.