Patent Publication Number: US-7215901-B2

Title: Process cartridge and electrophotographic image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application is a Divisional Application of U.S. application Ser. No. 11/007,214 filed Dec. 9, 2004, now U.S. Pat. No. 7,130,557. 

   FIELD OF THE INVENTION AND RELATED ART 
   The present invention relates to a cartridge and an electrophotographic image forming apparatus usable with the process cartridge. 
   Here, the electrophotographic image forming apparatus is an apparatus for forming the image on a recording material (recording sheet, OHP sheet or the like) through an electrophotographic image forming process. It includes an electrophotographic copying machine, an electrophotographic printer or the like. 
   The process cartridge is a cartridge containing as a unit an electrophotographic photosensitive member and process means including at least one of charging member and developing member, which cartridge is detachably mountable to a main assembly of the electrophotographic image forming apparatus. 
   With the electrophotographic image forming apparatus of the process cartridge type, the process cartridge can be mounted to or demounted from the main assembly of the image forming apparatus by the user without an expert serviceman. Therefore, the operationality of the image forming apparatus is remarkably-improved. 
   In such an electrophotographic image forming apparatus, it is necessary to supply electric voltages to a charging member for electrically charging the electrophotographic photosensitive member (photosensitive drum), a developing member for developing an electrostatic latent image formed on the photosensitive drum, and the like, which are contained in the process cartridge. 
   Heretofore, the cartridge is provided with an input electrical contact for electrical connection between the cartridge and the main assembly of the apparatus when the cartridge is mounted in place in the main assembly of the image forming apparatus. On the other hand, the main assembly of the apparatus is provided with an output contact. With this structure, when the cartridge is mounted to the main assembly of the apparatus, the input electrical contact is connected with the output contact. By doing so, the voltage can be supplied from the main assembly of the apparatus to the cartridge. 
   More particularly, the following structure is known. 
   A movable protection plate covering the contact member (the output contact) is provided in the main assembly of the apparatus. When the printer (image forming apparatus) is subjected to a maintenance operation, the operator and/or a tool is prevented from touching the contact member. By inserting motion of the cartridge into the main assembly of the apparatus, the protection plate is retracted to a retracted position. By doing so, the electrical connection is permitted between the contact member in the main assembly of the apparatus and the contact member on the cartridge (input electrical contact) (paragraphs ([0012 ]–[0015], FIG. 1-FIG. 3 of Japanese Laid-open Patent Application Hei 7-77921). 
   When the unit is dismounted from the main assembly of the apparatus, a connector pin (output contact) is hidden inside a partition wall. By doing so, the serviceman or user is prevented from touching the connector pin. By the insertion of the unit into the main assembly of the apparatus, the connector pin enters the unit insertion space. Thus, the connector pin and connector portion of the unit (input electrical contact) are electrically connected (Japanese Laid-open Patent Application Sho 62-215278). 
   In addition, the drum shutter is provided with a regulating portion. The regulating portion is effective to cover the electrical contact (input electrical contact). By doing so, the contact defect which may be caused by deposition of foreign matter on the electrical contact, can be prevented. By the entering of the cartridge into the main assembly of the apparatus, the electrical contact of the cartridge and the electrical contact of the main assembly of the apparatus (output contact) are electrically connected. (Japanese Laid-open Patent Application Hei 10-74030). 
   A contact member (output contact) is provided and is movable between a retracted position and a regular position. By doing so, the contact portion of the cartridge (input electrical contact) and the contact member of the main assembly of the apparatus are contacted with each other in order. Before the cartridge is inserted into the main assembly of the apparatus, the contact member (output contact) is in the retracted position. When the cartridge is mounted to the main assembly of the apparatus, the contact member is moved to the regular position. By this, the contact portion and the contact portion are electrically connected with each other. (Japanese Laid-open Patent Application Hei 9-68833). 
   The present invention provides a further improvements in such structures. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is a principal object of the present invention to provide a process cartridge, an electrical connection mechanism and an electrophotographic image forming apparatus wherein reliability in an electrical connection between an electrical input contact of the process cartridge and an electrical output contact of the main assembly of the electrophotographic image forming apparatus is improved, when the process cartridge is mounted to the electrophotographic image forming apparatus. 
   It is another object of the present invention to provide a process cartridge, an electrical connection mechanism and an electrophotographic image forming apparatus wherein damage of electric circuit provided in the main assembly of the electrophotographic image forming apparatus can be effectively prevented. 
   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 view of the process cartridge according to an embodiment of the present invention. 
       FIG. 2  is a schematic side view of the structure of an image forming apparatus according to an embodiment of the present invention. 
       FIG. 3  is a perspective view of an image forming apparatus according to an embodiment of the present invention. 
       FIG. 4  is a perspective view of a mounting portion of the main assembly of the apparatus to accept the process cartridge according to the embodiment of the present invention. 
       FIG. 5  is a perspective view of a mounting portion of the main assembly of the apparatus to accept the process cartridge according to the embodiment of the present invention. 
       FIG. 6  is a perspective view of a process cartridge according to the embodiment of the present invention. 
       FIG. 7  a perspective view of a process cartridge according to the embodiment of the present invention. 
       FIG. 8  is a perspective view wherein the developing unit and the drum unit are separated from each other to illustrate the structure of the process cartridge according to an embodiment of the present invention. 
       FIG. 9  is a perspective view wherein the developing unit and the drum unit are shown as being separated to illustrate the structures of the process cartridge of the embodiment of the present invention. 
       FIG. 10  is a perspective view of the structure of a drum unit of a process cartridge according to an embodiment of the present invention. 
       FIG. 11  is a perspective view of the structure of a drum unit of a process cartridge according to an embodiment of the present invention. 
       FIGS. 12(   a )– 12 ( c ) are perspective views of the structure of a movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIGS. 13(   a ) and  13 ( b ) are perspective views of the structure of a movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIGS. 14(   a ) and  14 ( b ) are perspective views of the structure of an electrical contact portion provided in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 15  illustrates a schematic front view of the structure of a mounting portion provided in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIGS. 16(   a ) and  16 ( b ) are schematic side and top views respectively, of the structures of the movable operation member and the electrical contact of the image forming apparatus according to the embodiment of the present invention. 
       FIGS. 17(   a ) and  17 ( b ) are schematic side and top views, respectively, of the structures of the movable operation member and the electrical contact of the image forming apparatus according to the embodiment of the present invention. 
       FIGS. 18(   a ) and  18 ( b ) are schematic side and top views, respectively, of the structures of the movable operation member and the electrical contact of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 19  illustrates a schematic block diagram of the structure of a circuit board in the image forming apparatus according to the embodiment of the present invention. 
       FIG. 20  is a perspective view of the structure of the drum unit in the embodiment of the present invention. 
       FIG. 21  is a perspective view of the structure of the drum unit in the embodiment of the present invention. 
       FIG. 22  illustrates a schematic side view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 23  illustrates a schematic side view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 24  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 25  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 26  illustrates a schematic side view of the structures of the movable operation member and the electrical contact of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 27  illustrates a schematic side view of the structures of the movable operation member and the electrical contact of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 28  illustrates a schematic side view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 29  illustrates a schematic side view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 30  is perspective views of an image forming apparatus and a process cartridge according to a further embodiment of the present invention. 
       FIG. 31  is a schematic side view of structures of the movable operation member and the electrical contact of the image forming apparatus. 
       FIG. 32  is a perspective view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 33  is a perspective view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIG. 34  is a perspective view of the structure of the movable operation member of the process cartridge according to the embodiment of the present invention. 
       FIGS. 35(   a ) and  35 ( b ) are side views of a structure of a movable operation member according to a further embodiment of the present invention. 
       FIGS. 36(   a ) and  36 ( b ) are perspective views of an electrical contact of a process cartridge according to a further embodiment of the present invention. 
       FIG. 37  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 38  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 39  is a schematic side view of the structures of the moveable operation member and the electrical contact of the image forming apparatus. 
       FIG. 40  is a schematic side view of the structures of the movable operation member and the electrical contact of the image forming apparatus. 
       FIG. 41  is a perspective view showing a structure of a movable operation member of a process cartridge according to a further embodiment of the present invention. 
       FIG. 42  is a perspective view showing a structure of a movable operation member of a process cartridge according to a further embodiment of the present invention. 
       FIG. 43  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 44  is a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 45  is a schematic side view of the structures of the movable operation member and the electrical contact of the image forming apparatus. 
       FIG. 46  is a schematic side view of the structures of the movable operation member and the electrical contact of the image forming apparatus. 
       FIG. 47  is a perspective view showing a structure of a movable operation member of a process cartridge according to a further embodiment of the present invention. 
       FIG. 48  is a perspective view showing a structure of a movable operation member of a process cartridge according to a further embodiment of the present invention. 
       FIG. 49  illustrates a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
       FIG. 50  illustrates a perspective view of the structure of an electrical contact portion in the main assembly of the image forming apparatus according to the embodiment of the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A description will be provided as to a process cartridge, an electrical connection mechanism and an electrophotographic image forming apparatus according to an embodiment of the present invention. 
   Embodiment 1 
   (1) General Structure of Process Cartridge: 
   Referring to  FIG. 1 , a process cartridge B (cartridge) according to a first embodiment of the present invention will be described.  FIG. 1  is a sectional view of the cartridge B. 
   In  FIG. 1 , the cartridge B comprises an electrophotographic photosensitive drum (photosensitive drum)  107 . As shown in  FIG. 2 , when the cartridge B is mounted to the main assembly A of the electrophotographic image forming apparatus (main assembly of the apparatus), the photosensitive drum  107  is rotatable by receiving a driving force from the main assembly A. 
   Disposed opposed to an outer surface of the photosensitive drum  107  is a charging roller  108  functioning as a charging member. The charging roller  108  is supplied with a voltage from the main assembly A (also denoted by reference numeral  100 ) of the apparatus and electrically charges the photosensitive drum  107 . The charging roller  108  is contacted to the photosensitive drum  107  and is rotated by the photosensitive drum  107 . 
   When the cartridge B is mounted to the main assembly A of the apparatus, the charging roller  108  is supplied with a voltage from the main assembly  100  of the apparatus through a charging output contact  144   a  ( FIG. 4 ) functioning as an output contact and a charging input electrical contact  141   a  ( FIG. 10 ) functioning as an input electrical contact. The charging roller  108  functions by receiving the voltage to electrically charge the photosensitive drum  107 . 
   The cartridge B includes a developing roller  110  functioning as a developing member. The developing roller  110  supplies the developer t into a developing zone adjacent a photosensitive drum  107 . The developing roller  110  develops an electrostatic latent image formed on the photosensitive drum  107  with the developer t. The developing roller  110  contains a magnet roller (stationary magnet)  111 . 
   When the cartridge B is mounted to the main assembly A of the apparatus, the developing roller  110  is supplied with a voltage from the main assembly  100  of the apparatus through a development output contact (unshown) functioning as an output contact and a development input electrical contact (unshown) functioning as an input electrical contact. The developing roller  110  functions by the thus applied voltage to develop the electrostatic latent image. 
   To the peripheral surface of the developing roller  110 , a developing blade  112  is contacted. The developing blade  112  functions to regulate an amount of the developer t deposited on the peripheral surface of the developing roller  110 . The developing blade  112  also functions to triboelectrically charge the developer t. 
   The developer t accommodated in the developer accommodating container  114  is supplied out into the developer chamber  113   a  by rotation of the stirring members  115 ,  116 . The developing roller  110  supplied with the voltage through the electrical contact  160   a  is rotated. By doing so, a layer of the developer having the triboelectric charge applied by the developing blade  112  is formed on the surface of the developing roller  110 . The developer t is transferred onto the photosensitive drum  107  in accordance with the pattern of the latent image. Thus, the latent image developed. 
   The developed image on the photosensitive drum  107  is transferred onto a recording material  102  by a transfer roller  104 . 
   Disposed opposed to the outer surface of the photosensitive drum  107  is an elastic cleaning blade  117   a . The cleaning blade  117   a  has an edge which is contacted to the photosensitive drum  107 . The blade  117   a  functions to remove the developer t remaining on the photosensitive drum  107  after transfer of the developed image onto the recording material  102 . The developer t removed from the surface of the photosensitive drum  107  by the blade  117   a  is accommodated in a removed developer container  117   b.    
   The cartridge B is constituted by the developing unit  119  and the drum unit  120 . 
   The developing unit  119  is constituted by the developing device frame  113  which is a part of the cartridge frame B 1 . The developing unit  119  contains the developing roller  110 , the developing blade  112 , the developer chamber  113   a , the developer accommodating container  114  and stirring members  115 ,  116 . A development input electrical contact (unshown) is provided exposed from the developing device frame  113 . 
   A drum unit  120  is constituted by a drum frame  118  which is a part of the cartridge frame B 1 . The drum unit  120  contains the photosensitive drum  107 , the cleaning blade  117   a , the removed developer container  117   b  and the charging roller  108 . The charging input electrical contact  141   a  is provided exposed from the drum frame  118 . 
   One end of the photosensitive drum  107  is supported by the drum frame  118 . An outer end of the drum shaft  139  functions as a cartridge guide  140 L 1  which will be described hereinafter referring to  FIG. 7 . 
   As will be understood from  FIG. 6 , cartridge guides  140 R 1 ,  140 R 2  are provided at one longitudinal end  120   a  of the drum unit  120 . As shown in  FIG. 7 , a cartridge guide  140 L 1  and another cartridge guide  140 L 2  are provided at the other longitudinal end  120   b.    
   The developing unit  119  and the drum unit  120  are rotatably coupled with each other by pins P ( FIG. 1 ). The developing roller  110  is urged to the photosensitive drum  107  by elastic members in the form of compression coil springs  121 ,  122  ( FIG. 8 ) which are provided between the units  119 ,  120 . Designated by  119   a  is an arm which is provided in the developing unit  119 . The arm  119   a  is engaged with the drum unit  120 , too. A pin P is penetrated through holes formed in the units  119 ,  120 . 
   Referring to  FIGS. 8 and 9 , a more detailed description will be provided. Free ends of arm portions  119   a ,  119   b  are provided adjacent longitudinally opposite end portions of the developing device frame  113 , and are provided with circular rotation holes  119   c , 119   d  extending parallel with developing roller  110 . At two positions of the longitudinal ends of the drum frame  118 , recesses  118   a ,  118   b  are provided to receive the arm portion  119   a ,  119   b . The arm portions  119   a ,  119   b  are inserted into recesses  118   a ,  118   b . Then, coupling members, namely, pins P are inserted into mounting holes  118   c ,  118   d  of the drum frame  118 . In addition, pins P are engaged into the rotation holes  119   c , 119   d  of the arm portions  119   a ,  119   b . Then, the pins P are press-fitted into holes (unshown) formed inside of the drum frame  118 . In this manner, the pins P are mounted. By doing so, the drum unit  120  and the developing unit  119  are rotatably coupled by the pins (coupling members) and therefore, they are rotatable about the pins. In this case, compression coil springs  121 ,  122  mounted to the base portions of the arm portion  119   a  and  119   b  abut to upper walls of the recesses  118   a ,  118   b  of the drum frame  118 . By this, the developing unit  119  is urged downwardly by the elastic force provided by the springs  121 ,  122 . In such a manner, the developing roller  110  is assuredly urged to toward the photosensitive drum  107 . 
   (2) Electrophotographic Image Forming Apparatus: 
   Referring to  FIG. 2 , a description will be provided as to the electrophotographic image forming apparatus  100  with which the cartridge B is usable.  FIG. 2  shows a general arrangement of an electrophotographic image forming apparatus (image forming apparatus)  100 . 
   A description will be provided as to a laser beam printer which is an exemplary image forming apparatus  100 . 
   In the image forming operation, a surface of the photosensitive drum  107  is uniformly charged by the charging roller  108 . A laser beam is emitted from a laser diode and is projected onto the photosensitive drum  107  in accordance with image information with optical means  101  including a polygonal mirror, lenses and deflection mirrors (unshown). By doing so, an electrostatic latent image is formed on the photosensitive drum  107  corresponding to the image information. The latent image is developed by the developing roller  110  which has been described hereinbefore. 
   On the other hand, in synchronism with the formation of the developed image, a recording material  102  in a cassette  103   a  is fed out by pick-up roller  103   b  and is fed to a transfer position by feeding rollers  103   c ,  103   d ,  103   e . At the transfer position, a transfer roller  104  (transferring means) is provided. The transfer roller  104  is supplied with a voltage. By this, the developed image formed on the photosensitive drum  107  is transferred onto the recording material  102 . 
   The recording material  102  now having the developed image transferred thereto is fed to fixing means  105  through a guide  103   f . The fixing means  105  includes a driving roller  105   c  and a fixing roller  105   b  containing a heater  105   a  therein. The fixing means  105  applies heat and pressure to the recording material  102  passing therethrough to fix the developed image on the recording material  102 . The recording material  102  is fed by a pair of rollers  103   g  and  103   h  onto a tray  106 . The roller  103   b , the pair of feeding rollers  103   c ,  103   d ,  103   e , the guide  103   f , the pair of rollers  103   g  and  103   h  and so on constitute feeding means  103  for the recording material  102 . 
   The cartridge B is mounted into or demounted from the main assembly A of the apparatus in the following manner. 
   As shown in  FIG. 3 , the operator or user opens a door  109  provided in the main assembly A of the apparatus. The cartridge B is demountably mounted to cartridge mounting means  130  provided in the main assembly A of the apparatus. 
   As shown in  FIGS. 4 and 5 , the mounting means  130  of this embodiment includes main assembly guides  130 R 1 ,  130 R 2 ,  130 L 1 ,  130 L 2  in the main assembly A of the apparatus. When the cartridge B is mounted to the main assembly A of the apparatus, it is inserted toward the cartridge mounting portion  130   a  such that cartridge guides  140 R 1 ,  140 R 2  ( FIG. 6 ) are guided by the main assembly guides  130 R 1 ,  130 R 2 , and the cartridge guides  140 L 1 ,  140 L 2  ( FIG. 7 ) are guided by the main assembly guides  130 L 1 ,  130 L 2 . 
   The cartridge guide  140 R 1  is engaged with the positioning portion  130 R 1   a  of the main assembly guide  130 R 1 , and the cartridge guide  140 R 2  is seated on the positioning portion  130 R 2   a  of the main assembly guide  130 R 2 . The cartridge guide  140 L 1  is engaged with the positioning portion  130 L 1   a  of the main assembly guide  130 L 1 , and the cartridge guide  140 L 2  is seated on the positioning portion  130 L 2   a  of the main assembly guide  130 L 2 . At this time, the cartridge B is demountably mounted to the cartridge mounting portion  130   a  by the mounting means  130 . By the cartridge B mounted in place in the cartridge mounting portion  130   a , the image forming operation is enabled. Here, the cartridge mounting portion  130   a  is the space occupied by the cartridge B which is mounted in place to the main assembly A of the apparatus by the mounting means  130 . 
   When the cartridge B is mounted, a coupling  134  ( FIG. 5 ) functioning as a driving force transmitting portion is at a retracted position, so that it does not interfere with the cartridge B which is being inserted for mounting. When the cover  109  is closed, the coupling  134  provided in the main assembly A of the apparatus is brought into engagement with a coupling  107   a  ( FIG. 6 ) of the cartridge B functioning as a driving force receiving portion. 
   (3) Charging Contact Member: 
   As shown in  FIG. 10 , the drum unit  120  is provided with an input contact member, i.e., a cartridge movable charging contact member  141  for receiving a charging bias voltage to be applied to the charging roller  108  from main assembly of the apparatus A. The charging contact member  141  is mounted on a cartridge operation member  142  (movable operation member) provided on the cartridge B. The charging contact member  141  includes an electrical contact  141   a , which is a part of the charging contact member  141 , provided on a side surface of the operation member  142  to electrically connect to an output contact member, i.e., main assembly charging contact  144   a , provided in the main assembly of the apparatus A. The structures of the operation member  142  and the main assembly charging electrical contact  144   a  will be described. 
   The other end portion  141   b  (( c ) of  FIG. 12 ) of the contact member  141  is contacted to an electrical contact  150   a  of the cartridge fixed charging contact member  150  provided on a drum frame  118  by operation of the operation member  142  (( b ) of  FIG. 13 ), which will be described hereinafter in detail. By doing so, the contact member  141  is electrically connected with the charging roller  108  in the drum unit  120 . 
     FIG. 11  is a perspective view wherein a side of the drum frame  118  has been removed so that inside of the drum frame  118  can be seen. As shown in this figure, the charging roller  108  has a metal shaft  108   a  which is rotatably supported by charging roller bearings  132  molded from electroconductive resin material. The charging roller  108  is mounted in the drum frame  118 . Between the bearing  132  and the drum frame  118 , there is provided a charging roller pressing spring (metal spring)  133 . By the elastic force of the spring  133 , the charging roller  108  is urged to the photosensitive drum  107  (unshown in  FIG. 11 ) with a predetermined force. The cartridge fixed charging contact member  150  is provided in the drum frame  118 . The contact member  150  includes an electrical contact  150   a  for electrical contact with the electrical contact  141   b  provided on the operation member  142 , and an electrical contact  150   b  for electrical contact with the spring  133 . The contact member  150  is made of an integral metal plate. The contact member  150  is fixed on the drum frame  118 . 
   (4) Cartridge Operation Member: 
   Referring to  FIGS. 12 , ( a ), ( b ) and ( c ), a description will be provided as to the structure of a movable operation member, i.e. cartridge operation member  142 , mounted on the cartridge B. 
   As shown in the figures, the operation member  142  is rotatably provided on a side opposite from a side where the coupling  107   a  ( FIG. 6 ) (driving force receiving portion) is provided, with respect to the longitudinal direction of the cartridge B which is also the longitudinal direction of the photosensitive drum  107  in this embodiment. The coupling  107   a  functions to receive a driving force from main assembly of the apparatus A when the cartridge B is mounted to the main assembly of the apparatus A. 
   The operation member  142  rotatably supported on the side surface of the drum frame  118  coaxially with the axis of the photosensitive drum  107 . The operation member  142  has a twisting coil spring  143  (elastic function member) in a cylindrical portion  142   a . One arm portion  143   a  thereof is hooked on a locking portion  142   e . The other arm portion  143   b  is mounted in a groove  118   n  formed in a side surface of the drum frame  118 . By doing so, the operation member  142  is normally urged in a direction of an arrow a by the elastic force of the spring  143 . The operation member  142  thus urged by the spring  143 , abuts the abutting portion  118   e  at the abutting portion  142   b . By this, the operation member  142  is positioned in the rotational direction. When the operation member  142  rotates in the direction indicated by an arrow b, it is rotatable to an extent that abutting portion  142   c  abuts to the abutting portion  118   f . The operation member  142  is provided with the contact member  141 . The contact member  141  has an electrical contact  141   a  and an electrical contact  141   b . The contact member  141  is operable integrally with the operation member  142 . The abutting portion  142   b  and the abutting portion  142   c  are provided on the operation member  142 . The abutting portion  118   e  and the abutting portion  118   f  are provided on the drum frame  118 . The electrical contact  141   a  is contacted to the electrical contact  144   a , and the electrical contact  141   b  is contacted to the electrical contact  150   a.    
   In  FIGS. 13 , ( a ) and ( b ), the operation member  142  is shown only in the outer shape thereof to show the positional relation between the contact member  141  and the contact member  150 . 
   The operation member  142  is provided with the contact member  141 . The contact member  141  is integrally fixed so that at least the electrical contact  141   a  is exposed. In other words, the contact member  141  is mounted on the operation member  142  in the manner that at least the electrical contact  141   a  is outwardly exposed to permit contact with the electrical contact  144   a . The contact member  150  is fixed on the drum frame  118 . The contact member  141  has an electrical contact  141   b . The contact member  150  has an electrical contact  150   a.    
   As shown in (a) of  FIG. 13 , when the operation member  142  rotates in the direction indicated by arrow a, the electrical contact  150   a  is spaced from the electrical contact  141   b , and therefore, the contact member  141  and the contact member  150  are not electrically connected to each other. As shown in (b) of  FIG. 13 , when the operation member  142  rotates in the direction of an arrow b, the contact member  141  rotates with the operation member  142 . By doing so, the electrical contact  150   a  and the electrical contact  141   b  are brought into contact with each other. Thus, an electrical connection is established between the contact member  141  and the contact member  150 . The position in which the contact member  141  is electrically connectable which is the contact member  150  is also the position in which the electrical contact  141   a  is contactable with the electrical contact  144   a . In other words, at the position with which the electrical contact  150   a  and the electrical contact  141   b  are contacted with each other, the electrical contact  141   a  and the electrical contact  144   a  are also contacted with each other. 
   The rotating operation of the operation member  142  will be described in detail hereinafter. 
   (5) Charging Contact Member of Main Assembly of Apparatus A: 
   A description will be provided as to the main assembly charging electrical contact member which is the output contact member provided in the main assembly of the apparatus A. 
   As shown in  FIGS. 14 , ( a ) and ( b ), the electrical contact  144   a  is provided on an inner side surface of the main assembly of the apparatus A. The electrical contact  144   a  is contactable with the electrical contact  141   a  to apply the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A. The electrical contact  141   a  is a part of the cartridge movable charging electrical contact member  141  (input electrical contact member) provided in the cartridge B. The electrical contact  144   a  is a part of the main assembly charging electrical contact member  144 . When the cartridge B is not mounted in the main assembly of the apparatus A, the contact  144   a  is retracted to a retracted position so as not to project beyond the inner side plate  145  of the main assembly of the apparatus A. The contact member  144  is connected with a high voltage electric circuit (voltage source circuit E) provided in the main assembly of the apparatus A through a lead wire or the like. 
   In the main assembly of the apparatus A, there is provided a fixed engageable member (fixed member)  146  functioning an abutting portion so as to project beyond the inner side plate  145 . The engageable member  146  functions to rotate the operation member  142  in interrelation with insertion of the cartridge B into the main assembly of the apparatus A. The engageable member  146  is fixed on the inner side plate  145 . Downstream of the engageable member  146  with respect to the inserting direction of the cartridge B, one end portion  147   c  of the displaceable member  147  ( FIG. 16 ) is projected. The engaging portion  147   c  is movable in the directions of arrows c, d in interrelation with mounting and demounting of the cartridge B. As shown in (b) of  FIG. 14 , when the cartridge B is mounted to the main assembly of the apparatus A, the engaging portion  147   c  is pushed by the operation member  142  in the direction of an arrow (c). In interrelation with the operation of the displaceable member  147 , the contact  144   a  projects through the opening  145   a   2  formed in the inner side plate  145 . More particularly, the contact  144   a  projects to the mounting portion  130   a . By doing so, the contact  144   a  is contacted to the contact  141   a . Thus, the contact  144   a  disposed at the retracted position outside the inner side plate  145  rotationally comes to the electrical connection position inside the inner side plate  145 . 
   By this, supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, the foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   (6) Inner Structure of Main Assembly of Apparatus A: 
   Referring to  FIG. 16 , a description will be provided as to the internal structure of the main assembly A of the apparatus.  FIG. 15  is a front view of the inside of the main assembly A of the apparatus as seen from the front side D, that is, in the direction of mounting the cartridge B ( FIG. 3 ). 
   At the bottom surface of the main assembly of the apparatus A, that is, below the cartridge mounting portion  130   a  there is provided an apparatus controller circuit board EC ( FIG. 19 ). At one lateral side of the mounting portion  130   a  with respect to the mounting direction, there is disposed a motor M and a driving gear train (driving force transmitting means) M 1  for transmitting the driving force from the motor M to the coupling  134  or the like, outside the inside side surface  145   e  of the inner side plate  145 . 
   At the opposite lateral side of the mounting portion  130   a , the displaceable engaging portion  147   c  is disposed downstream of the engageable member (fixed member)  146  with respect to the inserting direction X of the cartridge B relative to the main assembly A of the apparatus. In addition, at least a part of the engaging portion  147   c  is overlapped with the fixed engageable member  146  as seen in the inserting direction X. In other words, a part of the engaging portion  147   c  is behind the fixed engageable member  146  as seen in the inserting direction X. More particularly, the displaceable member  147  is provided with the displaceable engaging portion  147   c . An engageable member  146  (fixed member) is fixed in the main assembly of the apparatus A, and the engaging portion  147   c  is disposed downstream of the engageable member (fixed member) with respect to the inserting direction X of the cartridge B. In addition, at least a part of the engaging portion  147   c  is overlaid with respect to the inserting direction X. 
   For this reason, even if the operator inserts his or her hand from the front side D into the main assembly A of the apparatus for the purpose of maintenance (jam clearance operation or the like) after the cartridge B is dismounted, the hand is blocked by the engageable member  146 . Therefore, the engaging portion  147   c  is effectively protected from inadvertently being accessed by the operator. The output contact  144   a  (not shown in  FIG. 15 ) placed in the retracted position is prevented from moving unintentionally to the electrical connection position. 
   (7) Operations of Movable Member and Charging Contact Member: 
   A description will be provided as to the operations of the operation member (movable member operation member)  142  and the main assembly charging contact member  144 . 
     FIGS. 16(   a ),  17 ( a ), and  18 ( a ) are views of the inner side plate  145  of the main assembly of the apparatus A as seen from an inside of the main assembly of the apparatus (in the direction of the arrow Y in  FIG. 14) .  FIGS. 16(   b ),  17 ( b ), and  18 ( b ) are the views as seen in the direction of arrow Z in  FIG. 16(   a ),  FIG. 17(   a ) and  FIG. 18(   a ). 
   As shown in these figures, a displaceable member  147  is mounted on an outside of an inner side plate  145  for rotation about a shaft portion  147   a . The contact member  144  is mounted on the contact supporting member  148 . The supporting member  148  is mounted on the inner side plate  145  for rotation about the shaft portion  148   a . The supporting member  148  is urged in the direction of an arrow e by the elastic force of the compression spring  149  (elastic function member). The displaceable member  147  and the supporting member  148  are abutted to each other at the abutting portion  147   b  and the abutting portion  148   b . Therefore, the displaceable member  147  and the supporting member  148  are interrelated with each other. 
   When the supporting member  148  is urged in the direction of an arrow e, the displaceable member  147  rotates in the direction of an arrow f. The abutting portion (unshown) of the displaceable member  147  abuts to an edge of an opening  145   a   1  of the inner side plate  145 . By this, the displaceable member  147  is correctly positioned. At this time, the contact  144   a  is positioned at the retracted position which is retracted from the electrical connection position relative to the cartridge B and at which the contact  144   a  is not projected beyond the main assembly of the apparatus A of the inner side plate  145 . 
     FIGS. 16(   a ) and ( b ) illustrate the states in the process of inserting the cartridge B into the main assembly A of the apparatus. The cartridge B is inserted in the direction of an arrow X along the main assembly guides  130 L 1 ,  130 L 2 .  FIGS. 16(   a ) and  16 ( b ) show a state in which the cartridge B is inserted to the position immediately before the operation member  142  is contacted to the engageable member  146 . 
   As described hereinbefore, at the position of  FIGS. 16(   a ) and  16 ( b ), the operation member  142  is urged in the direction of an arrow a by the elastic force of the spring  143 . The operation member  142  is at rest at a position with which the abutting portion  142   b  and the abutting portion  118   e  are abutted to each other. The contact  144   a , as described hereinbefore, is at the retracted position in which it does not project beyond the inner side plate  145 . 
     FIGS. 17(   a ) and  17 ( b ) show a state in which the cartridge B is inserted further from the position of  FIGS. 16(   a ) and  16 ( b ). In the position shown in  FIGS. 17(   a ) and  17 ( b ), a first engaging portion  142   f  provided on the operation member  142  is abutted to the contact portion  146   a  provided in the engageable member  146 . By this, the operation member  142  rotates in the direction of an arrow b. And, the abutting portion  142   b  and the abutting portion  118   e  are separated from each other. A second engaging portion  142   d  provided on the operation member  142  pushes the displaceable member  147 . Therefore, the displaceable member  147  rotates in the direction of an arrow g. This rotates the supporting member  148  in the direction of an arrow u. The contact member  144  moves toward inside of the main assembly of the apparatus A out of the inner side plate  145 . 
     FIGS. 18(   a ) and  18 ( b ) show a state in which the cartridge B is further inserted until the cartridge B is completely mounted to the main assembly of the apparatus A (mounting portion  130   a ). The second engaging portion  142   d  of the operation member  142  rotates the displaceable member  147  in the direction of an arrow g. In interrelation therewith, the contact  144   a  is projected beyond the inner side plate  145 . The contact  144   a  is contacted to the contact  141   a . At this time, the operation member  142  is away from the engageable member  146 . The operation member  142  receives a reaction force from the displaceable member  147  in the direction of an arrow i. The operation member  142  is set at the position where the abutting portion  142   c  and the abutting portion  118   f  are abuted to each other. At this time, the positional relation between the contact member  141  and the electrode member  150  is such that the electrical contact  141   b  and the electrical contact  150   a  are contacted to each other. 
   As described hereinbefore, the operation member  142  is movable relative to the drum frame  118  (cartridge frame). When the cartridge B is inserted into the main assembly of the apparatus A, the operation member  142  is engaged with the fixed engageable member  146  fixed in the main assembly of the apparatus A to move relative to the drum frame  118 . After the operation member  142  is engaged with the fixed engageable member  146 , the operation member  142  is engaged with the displaceable engaging portion  147 C of the displaceable member  147  to move the displaceable member  147 . In interrelation with the movement of the displaceable member  147 , the main assembly charging electrical contact  144   a  (output contact) is moved against the elastic force of the compression spring  149  (elastic function member). The main assembly of the apparatus A has the electrical contact (output contact)  144   a  which is movable between an electrical connection position and a retracted position retracted from the electrical connection position. The main assembly of the apparatus A further includes a displaceable member  147  for moving the electrical contact  144   a  and a compression spring  149  for elastically urging the displaceable member  147  to move the electrical  144   a  from the electrical connection position to the retracted position. 
   As described in the foregoing, in this embodiment, when the cartridge B is inserted into the main assembly of the apparatus A, the electrical contact  144   a  is projected into the inside of the main assembly of the apparatus A by the operations of the operation member  142 , the displaceable member  147  and the supporting member  148 . And, it is contacted to the electrical contact  141   a  provided on the operation member  142 . A voltage is supplied from the voltage source S to the charging roller  108  through the electrical contact  144   a , the electrical contact  141   a , the electrical contact  141   b  and the electrical contact  150   a  by a control operation of the CPU  200  ( FIG. 19 ). 
   Thus, the contact  141   a  is contacted to the contact  144   a  now placed at the electrical connection position to receive the voltage for operating the charging roller  108  (process means). 
   By this, the charging roller  108  can receive the charging bias from the main assembly of the apparatus A. 
   By this, supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   In this embodiment, a contact member  141  is provided on a part of the operation member  142  to constitute the contact portion. However, most of or the entirety of the operation member  142  may be made of an electroconductive material. 
   (8) Apparatus Controller Circuit Board (Voltage Source Circuit). 
   Referring to  FIG. 19 , a description will be provided as to the engine controller circuit board EC provided in the main assembly of the apparatus A, usable with the present invention. The circuit board EC is disposed below the cartridge mounting portion  130   a . The circuit board EC comprises the CPU  200  and the electric circuit E. 
   The circuit board EC comprises the CPU  200  and the electric circuit E (voltage source circuit). The electric circuit E is constituted by a charging bias circuit E 1 , a developing bias circuit E 2  and a transfer/charging bias circuit E 3 . 
   The charging bias circuit E 1  generates a negative DC voltage and an AC voltage. It applies a voltage in the form of a sum of these voltages to the charging roller  108 . The charging roller  108  which receives the voltage and charges the photosensitive drum  107 . 
   The charging bias circuit E 1  applies the negative DC voltage also to the fixing roller  105   b  through a driving roller  105   c . The developing bias circuit E 2  generates a negative DC voltage and an AC voltage. The developing roller  110  is supplied with a voltage in the form of a sum of these voltages. The developing roller  110  receives the voltage to develop the electrostatic latent image with the developer. The transfer bias circuit E 3  generates a positive or negative DC voltage. It applies the positive or negative DC voltage to the transfer roller  104 . 
   Thus, the charging roller  108  is supplied with the voltage from the voltage source S through the charging bias circuit E 1 . The fixing roller  105   b  and the driving roller  105   c  are supplied with the voltage from the voltage source S through the charging bias circuit E 1 . The developing roller  110  is supplied with the voltage from the voltage source S through the developing bias circuit E 2 . The transfer roller  104  is supplied with the voltage from the voltage source S through the transfer/charging bias circuit E 3 . 
   These circuits E 1 , E 2 , E 3  are on-off-controlled or subjected to the controls in response to instructions from the CPU  200  provided on the circuit board EC. 
   As described in the foregoing, this embodiment provides the following advantageous effects. 
   (1) Even when the operator inserts his hand into the main assembly of the apparatus A for the purpose of jam clearance or the like with the process cartridge being out of the main assembly of the image forming apparatus, the main assembly charging contact does not project beyond the side surface. Therefore, the operator is prevented from easily touching the contact  144   a . At least a part of the displaceable member  147  for projecting the contact  144   a  is disposed behind the engageable member. Therefore, the operator is effectively prevented from touching the displaceable member. By this, the contact member  144  of the main assembly of the apparatus is protected from the application of electrostatic noise. Thus, the elements of the electric circuit in the main assembly of the apparatus are protected from damage. In addition, the contact is protected from sweat of the user or grease, so that a conduction defect can be prevented beforehand. 
   (2) The movement of the cartridge operation member is interrelated with the mounting and demounting operation of the cartridge. Therefore, there is no need for a special operation to contact the contacts with each other. 
   (3) The contact member is disposed opposite the driving side. Therefore, the space in the main assembly of the image forming apparatus can be efficiently used. Accordingly, the apparatus can be downsized. 
   (4) The electrical contact of the cartridge B is disposed below the cartridge B. This improves the assembling property. In such a case, the operation member  142  can be moved upwardly. With this structure, the operation member  142  does not project toward the main assembly side of the apparatus. By this, the main assembly of the apparatus can be downsized. 
   (5) The operation member  142  is urged by an elastic force of the elastic function member. Therefore, when the cartridge B is inserted into the main assembly of the apparatus A, the operation member is moved against the elastic force. This is effective to suppress any impact upon insertion of the cartridge B into the main assembly of the apparatus A. Thus, the generation of large vibration of the main assembly of the apparatus or of the cartridge can be avoided. In addition, the toner leakage can be prevented. Furthermore, the impact upon the abutment of the electrical contact of the cartridge to the electrical contact of the main assembly can be suppressed. 
   (6) The operation member is rotatable about an axis which is coaxial with the rotational axis of the photosensitive drum. By doing so, it is not necessary to use an additional rotation shaft, and therefore, the cartridge can be downsized. Since the operation member is provided on the side surface of the cartridge, the assembling property is improved. 
   (7) By this, the supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   In the foregoing embodiments, when the cartridge B is mounted to the main assembly of the apparatus A, the charging member, more particularly, the charging roller  107  (process means) receives the voltage from the main assembly of the apparatus  100  through the charging output contact  144   a  as the output contact and the charging input electrical contact  141   a  as the input electrical contact. 
   However, the present invention is not limited to such a structure. In an alternative, using structures similar to those described in the foregoing, when the cartridge B is mounted to the main assembly of the apparatus A, the developing roller  110  receives the voltage from the main assembly of the apparatus  100 . In such a case, the developing roller  110  receives the voltage from the main assembly of the apparatus  100  through a development output contact (unshown) as the development output contact and the development input electrical contact (unshown) as the input electrical contact. In a further alternative, voltages may be supplied to the charging roller  108  and to the developing roller  110 . Thus, the process means is enabled. By such a voltage supply system, the process means is enabled. 
   Therefore, the following embodiments will be described with respect to the charging roller  108  and/or developing roller  110 , but the present invention is not limited to such examples. The present invention is applicable to voltage supply from the main assembly of the apparatus  100  to another process means such as the developing roller  110 . 
   Embodiment 2 
   Referring to  FIG. 20-FIG .  27 , the second embodiment will be described. 
   The cartridge B and the image forming apparatus  100  have substantially the same structures as Embodiment 1. The same reference numerals as in Embodiments 1 and 2 are assigned to the elements having the corresponding functions in this embodiment, and the detailed description thereof is omitted for simplicity. 
   (1) Movable Operation Member of Cartridge B. 
     FIGS. 20 and 21  are perspective views of a front portion of the cartridge B according to this embodiment of the present invention, with respect to a mounting direction in which the cartridge B is mounted to the main assembly of the apparatus A. They also illustrate a drum unit  120  of the cartridge B. 
   In this embodiment, the cartridge B comprises a drum unit  120  and a developing unit  119 , which are rotatably coupled with each other. 
   As shown in  FIG. 20 , a side surface of the operation member  142  is provided a contact member  141  which is fixed to the side surface and which is exposed. The contact member  141  is fixed on the operation member  142 , and the contact  141   a  thereof is exposed. 
   As shown in  FIG. 21 , the drum frame (cartridge frame)  118  is provided with a cartridge fixed charging contact member  150 . Similarly to Embodiment 1, when the operation member  142  rotates in the direction of arrow a, the contact  141   b  and the contact  150   a  of the contact member  150  are not electrically connected. On the other hand, when the operation member  142  rotates in the direction of an arrow b, the contact member  141  and the contact member  150  are electrically connected. 
   Referring to  FIG. 22 , the structure of the operation member  142  will be described. 
   As shown in this figure, a side surface of the cartridge B is provided with the operation member  142  which is rotatably mounted to the drum frame  118 . 
   To the developing unit  119 , a cartridge arm  270  is rotatably provided for rotation about a cartridge shaft portion  271 . 
   The operation member  142  is rotatably connected with one end of a first link  274  by a first cartridge connecting portion  272 . The other end of the link  274  is rotatably connected with a second cartridge connecting portion  273 . To the other end of the link  274 , one end of the arm  270  is rotatably connected by a second cartridge connecting portion  273 . 
   To the other end of the arm  270 , a second link  275  (operating member) is rotatably mounted at a third cartridge connecting portion  276 . The link  275  is slidably mounted on a mounting portion  277  at the side surface of the developing unit  119 , for sliding motion in the directions of arrows  1  and m. 
   Between the link  274  and the connecting portion  273 , an end of a tension spring  278  is hooked. The other end of the tension spring  278  is mounted on a shaft portion  279 . 
   With the structure of this embodiment, the operation member  142  is rotatable by manual operation of the link  275  by the operator. 
     FIG. 22  shows a state in which the operator manually moves the link  275  in the direction of the arrow m (pulling toward the operator). When the second link  275  is moved in the direction of m, the arm  270  rotates in the couterclockwise direction in this figure. This rotates the operation member  142  in the direction of an arrow k. 
   Here, similarly to Embodiment 1, the operation member  142  is rotatable until the abutting portion  142   b  of the operation member  142  ( FIG. 12 ) abuts to the operation member abutting portion  118   e . The arrangement is such that when the operation member  142  abuts to the operation member abutting portion  118   e , the second connecting portion  273  is disposed in a left side of a line connecting the center of rotation of the arm  270  (the center of the shaft  271 ) and the center of the shaft portion  279 . One end of the tension spring  278  is mounted on the shaft portion  279 . Therefore, the elastic force of the spring  278  tends to rotate the arm  270  in the couterclockwise direction. Therefore, the operation member  142  is placed of the position where it abuts to the abutting portion  118   e.    
     FIG. 23  shows a state in which the operator manipulates the second link  275  in the direction of the arrow w (pushing direction). By the operation of the link  275 , the arm  270  rotates in the clockwise direction. This rotates the operation member  142  in the direction of an arrow k. 
   At this time, the operation member  142  is rotatable until the operation member  142  abuts to the abutting portion  118   f  ( FIG. 12 ), similarly to Embodiment 1. The arrangement is such that when the operation member  142  abuts to the operation member abutting portion  118   f , the second connecting portion  273  is disposed in a right side of a line connecting the center of rotation of the arm  270  (the center of the shaft  271 ) and the center of the shaft portion  279 . Therefore, the elastic force of the spring  278  tends to rotate the arm  270  in the clockwise direction. Therefore, the operation member  142  is placed of the position where it abuts to the abutting portion  118   f.    
   When the operation member  142  is in such a state, the contact  141   a  is in the position of electrical connection with the contact  144   a.    
   (2) Charging Contact Member of Main Assembly of Apparatus A: 
   A description will be provided as to the main assembly charging electrical contact member  144  (input electrical contact member) and an electrical contact (input electrical contact)  144   a.    
   As shown in  FIG. 24 , the main assembly charging contact member  144  is provided on an inside surface of the main assembly of the apparatus A. With no cartridge B mounted in the main assembly of the apparatus A, the electrical contact  144   a  of the electrical contact member  144  is at a retracted position where the electrical contact  144   a  is not projected beyond the inner side plate  145  of the main assembly of the apparatus A. The contact member  144  is effective to supply the charging bias voltage to the charging roller  108  when it is contacted to the cartridge movable charging contact member  141  of the cartridge B. 
   Into an inside the main assembly of the apparatus A, one end portion of the operation member displaceable member  147  (displaceable engaging portion) is projected. The displaceable member  147  is interrelated with the operation of the operation member  142  to operate the contact member  144 . 
   A fixed member  300  is disposed upstream of the displaceable member  147  with respect to the mounting direction X of the cartridge B. The fixed member is fixed on the main assembly of the apparatus A. 
   The one end portion  147   c  moves in the directions of arrows c, d in interrelation with the operation member  142 . After the cartridge B is mounted to the main assembly of the apparatus A (after the cartridge B is mounted to the mounting portion  130   a ), the operator manually operates the second link  275 . As shown in  FIG. 25 , by such an operation, the displaceable member  147  is pushed by the operation member  142  ( FIG. 23 ) in the direction of an arrow c. Then, the contact  144   a  is projected by rotational motion from the inner side plate  145  toward the mounting portion  130   a  side in interrelation with the operation of the displaceable member  147 . By doing so, the contact  144   a  is contacted to the contact  141   a . In other words, the contact  144   a  is moved relative to the contact  141   a  and is contacted to the contact  141   a , which is stationary. 
   By this, supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   (3) Operations of Movable Member and Charging Contact Member: 
   A description will be provided as to the cartridge operation member  142  (movable operation member) provided on the cartridge B and the main assembly charging contact member  144  (output contact member) provided in the main assembly of the apparatus A.  FIG. 26  is a schematic view illustrating an operation when the cartridge B is mounted to the main assembly of the apparatus A. 
   In this embodiment, the structure or the like of the displaceable member  147  and the supporting structure of the contact member  144  are the same as in Embodiment 1, and therefore, the detailed description thereof is omitted for simplicity. 
     FIG. 26  is a view of an inner side plate  145  provided in the main assembly of the apparatus A as seen from an inside of the main assembly of the apparatus (in the direction of arrow Y in  FIG. 24 ). 
     FIG. 26  shows a position wherein the cartridge B is mounting is set in the main assembly of the apparatus A. In  FIG. 26 , the operation member  142  is disposed at a lower position. Namely, the cartridge B is in the state shown in  FIG. 22 . 
   In the state of  FIG. 26 , the operator manually moves the second link  275  in the direction of arrow  1  (pushing direction). By this operation, as described hereinbefore, the operation member  142  rotates in the direction of an arrow b through the cartridge arm  270  and the first link  274 . At this time, the second engaging portion  142   d  of the cartridge operation member  142  is contacted to an inclined surface  147   d  of the displaceable member  147 . By doing so, the displaceable member  147  moves in the direction of an arrow d ( FIG. 27 ). This causes the electrical contact  144   a  to project into the main assembly of the apparatus in interrelation with the displaceable member  147 . Therefore, the contact  144   a  is contacted with the contact  141   a  to enable charging bias application to the charging roller  108 . 
   In this embodiment, the advantageous effects (1)–(7) described above with respect to said Embodiment 1 are provided, except for (2) and (5). 
   Furthermore, according to this embodiment, the electrical connection is established between the cartridge B and the main assembly of the image forming apparatus B by the operation of the operator per se after the cartridge B is set in the main assembly of the image forming apparatus A. By this, the operator can confirm the connection between the electrical contacts  141   a ,  144   a  by himself. 
   Embodiment 3 
   Referring to  FIG. 28-FIG .  31 , the third embodiment will be described. 
   The structures of the cartridge B and the image forming apparatus  100  of this embodiment are similar to those of Embodiment 1 and Embodiment 2. The same reference numerals as those used to describe Embodiments 1 and 2 are assigned to elements having corresponding functions, and the detailed descriptions for such elements are omitted for simplicity. 
   In this embodiment, the operation of the second link  275  in Embodiment 1 and Embodiment 2, is interrelated with the operation of closing the cartridge door  109  (main assembly openable member) provided in the main assembly of the image forming apparatus  100 . The same reference numerals as those used to describe Embodiment 2 are assigned to elements having corresponding functions, and the detailed descriptions for such elements are omitted for simplicity. 
   Referring to  FIG. 28 , a description will be provided as to the structure of the operation member  142  mounted to the cartridge B of this embodiment. 
   As shown in this figure, a side surface of the cartridge B is provided with the operation member  142 , which is rotatably mounted to the drum frame  118 . The contact member  141  is provided on a side surface of the operation member  142  and is exposed to the outside. The operation member  142 , similarly to Embodiment 2, is connected with the second link  275  through the first link  274  and the cartridge arm  270 . The structure of the link and the arm are similar to those of Embodiment 2, and therefore, the detailed description thereof is omitted for simplicity. 
   In this embodiment, the tension spring  278  is stretched between the connecting portion  273  and the shaft portion  279 , too. The shaft portion  279  is disposed at a position different from that in Embodiment 2. 
   More particularly, as shown in  FIGS. 28 and 29 , the tension spring  278  is disposed at such a position that the cartridge arm  270  normally receives a force in the counterclockwise direction in the figure. Therefore, the operation member  142  is always subjected to the rotational force in the counterclockwise direction. The second link  275  receives normally an elastic force in the direction of an arrow m. 
     FIG. 28  shows a state in which the operation member  142  is rotated in the couterclockwise direction and positioned there.  FIG. 29  shows a state in which the operation member  142  is rotated in the clockwise direction and positioned there. 
     FIG. 30  shows a state in which the cartridge B is set in the main assembly of the apparatus A. The structure of the contact member  144  and the displaceable member  142  for moving it are similar to those of Embodiment 2. Therefore, the detailed description thereof is omitted for simplicity. 
   An end of a second link  275  for rotating the movable member  142  is projected from the cartridge B. Inside the cartridge door  109 , there is provided a rib  109   a  for pushing the second link  275 . The door  109  can be opened or closed relative to the main assembly of the apparatus. The door  109  opens relative to the main assembly of the apparatus ( FIG. 33 ), and enables mounting and demounting of the cartridge B relative to the main assembly of the apparatus. 
   As shown in  FIG. 31 , after the cartridge B is mounted to the main assembly of the apparatus A, the operator manually closes the door  109  in the direction of an arrow f. Then, the rib  109   a  pushes the end of the second link  275  (operation member) in the direction of the arrow C. By doing so, similarly to Embodiment 2, the operation member  142  rotates in the direction of an arrow g through the cartridge arm  270  and the first link  274 . This brings the second engaging portion  142   d  of the operation member  142  into contact to the inclined surface  147   d  of the displaceable member  147 . Therefore, the displaceable member  147  is moved. The rib  109   a  is disposed inside the door  109 . 
   In this manner, the electrical contact  144   a  ( FIG. 24-FIG .  27 ) is contacted to the electrical contact  141   a  by interrelation with the displaceable member  147 . By this, the charging roller  108  can receive the charging bias from the main assembly of the apparatus A. 
   By this, supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   As described in the foregoing, the operation member  142  has an engaging portion  142   d  for engagement with the displaceable member  147 . The operation member  142  operates the second link  275  (operating member) by the operator manually closing the door  109  after the cartridge B is mounted in the main assembly of the apparatus A. The operation member  142  is rotated by such an action, and the engaging portion  142   d  is engaged with the displaceable member  147 . When the cartridge B is removed from the main assembly of the apparatus A, the operator opens the door  109 . The operation member  142  is rotated in the direction of an arrow a by the elastic force of the tension spring  278 , as described hereinbefore. By this, the operation member  142  returns to the initial state (retracted state), namely, the operation member  142  takes a lower position ( FIG. 28 ). 
   This embodiment also provides the advantageous effects similar to Embodiment 2. 
   Moreover, according to this embodiment, the movement of the second link  275  is interrelated with the movement of the door  109 . By doing so, the operator is not required to make an additional operation to bring the contact  144   a  and the contact  141   a  to contact to each other. 
   Embodiment 4 
   Referring to  FIG. 32-FIG .  40 , a fourth embodiment will be described. 
   The cartridge B and the image forming apparatus  100  have substantially the same structures as with Embodiment 1. A description will be provided as to the structures of the portions which are different from those of Embodiment 1, Embodiment 2 and Embodiment 3. The same reference numerals as those used to describe the earlier embodiments are assigned to elements having corresponding functions, and the detailed descriptions for such elements are omitted for simplicity. 
   (1) Operation Member and Charging Contact Member of Cartridge: 
     FIG. 32-FIG .  34  show the cartridge B of this embodiment. In this embodiment, the cartridge B comprises a drum unit  120  and a developing unit  119  which are rotatably coupled with each other. 
   The cartridge B is provided on the drum frame  118  with a drum shutter  170  for protecting the photosensitive drum  107 . The shutter  170  has a shutter portion  170   a  for covering the photosensitive drum  107  and supporting arm  170   b  at each of the opposite ends (one end portion only is shown in the figure). The shutter  170  is rotatably mounted for rotation about the shaft portion  170   c.    
   The shutter  170  rotates in the direction of the arrows in interrelation with the mounting operation of the cartridge B to the main assembly of the apparatus A. It moves from the position ( FIG. 38 ) for protecting the photosensitive drum  107  to the position ( FIG. 39 ) for exposing the photosensitive drum  107 . 
   The operation member  142  is mounted on the drum frame  118  for rotation about the shaft  118   h  ( FIG. 34 ). The operation member  142  is provided outside a passing path of the supporting arm  170   b  when it rotates. 
   The contact member  141  is fixed on the operation member  142  and is exposed there. The cartridge operation member  142  rotates in the direction of an arrow b in interrelation with an operation of mounting the cartridge B to the main assembly of the apparatus A, similarly to the shutter  170 . By this, the electrical contact  141   a  is moved from a retracted position ( FIG. 32 ) 
   where it is out of contact from the electrical contact  144   a  to a contact position ( FIG. 33 ) where it is contactable to the electrical contact  144   a.    
   In  FIG. 34 , the operation member  142  is provided in the cylindrical portion  142   a  with a twisted coil spring  143 . The elastic force of the spring  143  urges the operation member  142  to rotate in the direction of an arrow a. The abutting portion  142   b  of the operation member  142  urged by the elastic force of the spring  143  abuts the abutting portion  118   e . By doing so, the operation member  142  is set at a position with respect to the rotational direction. 
   When the operation member  142  rotates in the direction of an arrow b, it rotates until the abutting portion  142   c  abuts to the abutting portion  118   f  ( FIG. 35(   b )). 
     FIGS. 36(   a ) and  36 ( b ) are perspective views wherein a side of the drum frame  118  has been removed so that inside of the drum frame  118  can be seen. The charging roller  108  is rotatably supported by a charging roller bearing  132  which is molded from an electroconductive resin material and which supports the metal shaft  108   a  of the charging roller  108 . The charging roller  108  is mounted in the drum frame  118 . The bearing  132  is provided with a pressing spring  133 . The cartridge fixed charging contact member  150  includes an electrical contact  150   a  for contacting to an arm portion  143   b  of the twisted coil spring  143  and an electrical contact  150   b  for contacting to the spring  133 . 
   The contact member  141  is mounted on the operation member  142  and is exposed there. The contact member  141  includes an electrical contact  141   a  for contacting to the electrical contact  144   a  and an electrical contact  141   b  for contacting to the arm portion  143   a  of the spring  143 . In other words, one of the arm portions  143   b  of the spring  143  is hooked and locked by the contact  150   a , and the other arm portion  143   a  is hooked on the contact  141   b . By doing so, the spring  143  urges the operation member  142  to rotate in the direction of an arrow a, and effects establishment of the electrical connection between the associated contacts. 
   More particularly, an electrical path is established from the contact  141   a  of the contact member  141  to the contact  150   b  through the contact  141   b , the arm portion  143   a , the arm portion  143   b  and the contact  150   a . Then, the electric connection is established from the contact  150   b  to the charging roller  108  through the spring  133 , the bearing  132  and the metal shaft  108   a.    
   (2) Charging Contact Member of Main Assembly of Apparatus A: 
   A description will be provided as to the main assembly A of the apparatus to which the cartridge B is mountable. 
   As seen in  FIG. 38 , a contact member  144  is provided on an inner side surface of the main assembly of the apparatus A. 
   When the cartridge B is not yet mounted to the main assembly of the apparatus A, the contact member  144  is at a retracted position where it does not project beyond a cover  171 , which is provided on an inner side surface of the main assembly of the apparatus A. The contact member  144  is electrically connected to a high voltage electric circuit (voltage source circuit E) disposed inside the main assembly of the apparatus A by lead lines or the like. 
   Inside the main assembly of the apparatus A, a fixed engageable member (fixed member)  146  for rotating the operation member  142  is provided projected from the inner side surface. The displaceable member  147  is disposed downstream of the fixed engageable member  146  with respect to the mounting direction X of the cartridge B. 
   The displaceable member  147  is mounted rotatably about the shaft portion  147   a . The displaceable member  147  rotates in interrelation with mounting and demounting operation of the cartridge B. When the cartridge B is mounted to the main assembly of the apparatus A, the displaceable member  147  is pushed by the cartridge operation member  142  of the cartridge B in the direction of an arrow c, as shown in  FIG. 38 . By this, the contact  144   a  is uncovered and projected to contact to the electrical contact  141   a.    
   (3) Operations of Movable Member and Charging Contact Member: 
   A description will be provided as to the operations of the operation member  142  and the contact member  144 .  FIGS. 39 and 40  are schematic view illustrating the operation of mounting the cartridge B into the main assembly of the apparatus A. 
     FIGS. 39 and 40  are the views of the inner side plate  145  as seen from an inside of the main assembly of the apparatus A (as seen in the direction of arrow Y in  FIG. 37 ).  FIG. 39  shows a state in which the cartridge B is in the process of insertion into the main assembly of the apparatus A, and  FIG. 40  shows a state in which the cartridge is set in the main assembly of the apparatus A. 
   As shown in  FIG. 39 , the displaceable member  147  is mounted on the inner side plate  145  rotatably about the shaft portion  147   a . The contact member  144  is mounted on the displaceable member  147 . The displaceable member  147  is urged by a compression spring (unshown) in the direction of an arrow d. The abutting portion  147   d  of the displaceable member  147  is abutted to the abutting portion  145   d  of the inner side plate  145  to be positioned. At this time, the contact  144   a  is at a position where it does not project into the main assembly of the apparatus A beyond the cover  171 . 
   The cartridge B is inserted in the direction of arrow X along the guide portions  130 L 1 ,  130 L 2 . 
   In the position shown in  FIG. 39 , as described hereinbefore, the operation member  142  is urged by the elastic force of the spring  143  in the direction of an arrow a. The operation member  142  is at rest at the position where the abutting portion  142   b  abuts to the abutting portion  118   e . The contact member  144  is at the position not projecting beyond the cover  171 . The contact  141   a  is also at the retracted position. 
   When the cartridge B is further inserted into the main assembly from the position of  FIG. 39 , the first engaging portion  142   f  of the operation member  142  abuts the contact portion  146   a  of the fixed engageable member  146 . By this, it is rotated in the direction of an arrow b. By doing so, the second engaging portion  142   d  of the operation member  142  pushes one end portion  147   c  of the displaceable member  147  upwardly. Therefore, the displaceable member  147  rotates in the direction of an arrow g. And, the electrical contact  144   a  projects beyond the cover  171 . 
   As shown in  FIG. 40 , when the cartridge B is completely mounted to the main assembly of the apparatus A, the contact  141   a  moves to the contact position. And, the contact member  144  projects beyond the cover  171 . As a result, the contact  144   a  and the contact  141   a  are contacted to each other. This enables the supply of the charging bias to the charging roller  108  of the cartridge B from the main assembly A of the apparatus. 
   By this, supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   This embodiment also provides the advantageous effects similar to Embodiment 2. 
   Furthermore, according to this embodiment, the cartridge operation member  142  is disposed outside the passing path of the supporting arm  170   b  with respect to the rotation axis of the drum shutter  170 , so that there is no need to consider the effect of the opening and closing timing of the drum shutter  170  and the cartridge operation member  142  upon the mounting and demounting of the cartridge B, so that image forming apparatus can be downsized. 
   Embodiment 5 
   Referring to  FIG. 41-FIG .  46 , a fifth embodiment of the present invention will be described. 
   The structures of the cartridge B and the image forming apparatus  100  of this embodiment are similar to those of Embodiment 1-Embodiment 4. The same reference numerals as with the Embodiments 1–4 are assigned to the elements having the corresponding functions, and the detailed descriptions for such elements are omitted for simplicity. 
   (1) Cartridge Operation Member: 
     FIG. 41-FIG .  46  show a cartridge B of this embodiment of the present invention. In this embodiment, the cartridge B comprises a drum unit  120  and a developing unit  119  which are rotatably coupled with each other. 
   The drum frame  118  is provided with a drum shutter  170  and an operation member  142  which are rotatable relative thereto. 
   As shown in  FIG. 41 , a cam member  251  and a link arm member  252  are provided between the cartridge operation member  142  and a grip portion  300  at the same side as the side having the cartridge operation member  142  with respect to the longitudinal direction of the cartridge B. The cam member  251  is connected so as to interrelate with the operation of the operation member  142  by a link arm member  252 . The grip portion  300  functions to facilitate mounting and demounting of the cartridge B into and out of the main assembly of the apparatus. 
   The grip portion  300  is disposed on a top of the developing unit  119  of the cartridge B and is provided with an operation lever  253  (operation member) for operating the cam member  251 . The operation lever  253  is provided with a notch or a projected portion  253   a  for returning the lever  253  (manually operating member) to a stand-by position. The projected portion  253   a  is disposed on the grip portion  300 . 
   In this embodiment, as shown in  FIG. 42 , after the cartridge B is mounted to the main assembly of the apparatus A, the operator manually operates the projected portion  253   a , namely, the lever  253 . By this, the operation member  142  is rotated in interrelation with the lever  253 . The projected portion  253   a  is disposed on the grip portion  300 . However, the projected portion  253   a  is disposed at a position not touched by the operator when the operator grips the grip portion  300 . 
   (2) Charging Contact Member Provided in Main Assembly of Apparatus A: 
   A description will be provided as to the main assembly A of the apparatus to which the cartridge B is mountable. 
   As shown in  FIG. 44 , the inner side surface is provided with a main assembly charging contact member  144 . When the cartridge is not yet mounted in the main assembly of the apparatus A, the electrical contact  144   a  of the contact member  144  is at a retracted position where it does not project beyond the cover  171 . 
   The displaceable member  147  is mounted rotatably about the shaft portion  147   a . As shown in  FIG. 44 , the displaceable member  147  is pushed by the operation member  142  when the operator operates the lever  253 , and the displaceable member  147  rotates in the direction of an arrow c. Then, the contact  144   a  is uncovered. And, it is contacted to the contact  141   a  which is stationary. 
   Each of the mounting guide  130 L 1 ,  130 L 2  is provided with a cut-away portion  130 L 3 . Because of the provision of the cut-away portion  130 L 3 , the movement of the link arm member  152  is not interfered with. 
   (3) Operations of Operation Member and Charging Contact: 
   A description will be provided as to the cartridge operation member  142  of the cartridge B and the main assembly movable charging contact member  144  of the main assembly of the apparatus A.  FIGS. 45 and 46  are schematic view illustrating the operation of mounting the cartridge B into the main assembly of the apparatus A. 
     FIGS. 45 and 46  are the views of the inner side plate  145  as seen from an inside of the main assembly of the apparatus A (as seen in the direction of arrow Y in  FIG. 43 ).  FIG. 45  shows a state in which the cartridge B is set in the main assembly of the apparatus A, and before the lever  253  (operating member) is manipulated.  FIG. 46  shows a state in which the cartridge B is set in the main assembly of the apparatus A and the lever  253  has been operated. 
   As shown in  FIG. 45 , the displaceable member  147  is mounted on the inner side plate  145  rotatably about the shaft portion  147   a . The contact member  144  is mounted on the displaceable member  147 . The displaceable member  147  is urged in the direction of an arrow d by a compression spring (unshown). The contact  144   a  is at a position where it does not project into the main assembly of the apparatus (mounting portion  130   a  side) beyond the cover  171 . 
   The cartridge B is inserted in the direction of arrow X along the guide portions  130 L 1 ,  130 L 2 . 
   After the cartridge B is completely mounted in the main assembly of the apparatus A, the operation member  142  rotates in the direction of arrow b ( FIG. 46 ) upon the operator operating the lever  253 . By this, the engaging portion  142   d  pushes one end portion  147   c  of the displaceable member  147  (displaceable engaging portion). Therefore, the displaceable member  147  rotates in the direction of an arrow g. By this, the contact  141   a  moves to the contact position. The contact  144   a  is rotated and is projected into the inside of the apparatus beyond the cover  171 . As a result, the contact  144   a  and the contact  141   a  are contacted to each other. 
   By this, the supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   At this time, the operation member  142  is positioned by abutment between the abutting portion  142   c  and the abutting portion  1118   f.    
   This enables the device to supply the charging bias to the charging roller  108  of the cartridge B from the main assembly A of the apparatus. 
   This embodiment also provides the advantageous effects similar to Embodiment 2. 
   Embodiment 6 
   Referring to  FIG. 47-FIG .  50 , the sixth embodiment will be described. 
   The structures of the cartridge B and the image forming apparatus  100  of this embodiment are similar to those of Embodiment 1—Embodiment 5. The same reference numerals used to describe foregoing embodiments are assigned to elements having corresponding functions, and the detailed descriptions for such elements are omitted for simplicity. 
   In this embodiment, the operation of the cam member in said Embodiment 5 is interrelation with a closing operation of the cartridge door of the main assembly of the apparatus A. 
   Referring to  FIG. 47 , a description will be provided as to the structure of a cartridge operation member  142  mounted to the cartridge B in this embodiment. 
   Similarly to Embodiment 5, the operation member  142  is connected with the cam member  251  through the arm member  252 . Cam member  251  is provided with a projection  251   a  for rotating the cam member  251 . The operation member  142  is urged so as to rotate in the direction of the arrow a by a twisted coil spring. The structures of the arm member  252  and the cam member  251  are the same as with Embodiment 5, and therefore, the detailed description thereof is omitted for simplicity. 
     FIG. 49  shows a state in which the cartridge B is inserted into the main assembly of the apparatus A, and the cartridge door (openable member of the main assembly)  109  is not yet closed. The structures of the main assembly charging contact member  144  of the main assembly of the apparatus A and the displaceable member  147  are similar to those of said Embodiment 5, and therefore, the detailed description thereof is omitted for simplicity. 
   The door  109  is rotatable about the shaft  109   b .  FIG. 49  shows a state in which the door  109  is opened. An inside of the door  109  is provided with a rib  109   a  for pushing the projection  251   a  of the cam member  251  provided in the cartridge B. 
     FIG. 50  shows a state in which the cartridge B is set in the main assembly of the apparatus A, and the door  109  is closed. When the door  109  is closed in the direction of an arrow f, the rib  109   a  pushes the projection  251   a  of the cam member  251 . By doing so, similarly to Embodiment 5, the operation member  142  is rotated in the direction of an arrow b through the arm member  252 . And, the free end portion  142   d  is contacted to an inclined surface  147   c  of the displaceable member  147 . By this, the displaceable member  147  is moved. Then, the contact  144   a  is rotated and projected into the main assembly of the apparatus in interrelation with the displaceable member  147 . By this, the contact  144   a  is contacted to the contact  141   a . And, the application of the charging bias voltage to the charging roller  108  is enabled. 
   By this, the supply of the charging bias voltage to the charging roller  108  from the main assembly of the apparatus A is enabled. When the operation member  142  rotates, the contact  144   a  also rotates in a different direction. These contacts are brought into contact with each other while moving. The contacts make slight relative motion even after they are contacted. In this manner, the contact  141   a  rubs the surface of the contact  144   a . Therefore, the surface of the contact  141   a  and the surface of the contact  144   a  rub each other. By doing so, foreign matter, developer or the like deposited on the surfaces can be removed. Thus, the reliability of the electrical connection between the contact  141   a  and the contact  144   a  is improved. 
   When the cartridge B is removed from the main assembly of the apparatus A, the operator opens the door  109 . Then, as described hereinbefore, the elastic force of the twisted coil spring provided on the operation member  142  rotates the operation member  142  in the direction of an arrow a. By this, the operation member  142  returns to the initial state. 
   This embodiment also provides the advantageous effects similar to Embodiment 2. 
   The process cartridge B to which the present invention is applicable is not limited to a process cartridge for formation of the monochromatic image. But it may be a color cartridge for formation of a multicolor image (two-color images, three-color images, full-color images or the like) using a plurality of developing means. 
   The photosensitive member may be a photoconductor which may be an amorphous silicon, amorphous selenium, zinc oxide, titanium oxide, organic photoconductor (OPC) or the like. The photosensitive member may be in the form of a drum, a belt or another rotatable member, or a sheet, or the like. The photosensitive member may be in the form of a drum or a belt. In the case of a drum type photosensitive member, a cylinder of aluminum alloy or the like is coated with a photoconductor by evaporation or application or the like. 
   The present invention is preferably usable with various known developing methods, such as the magnetic brush developing method using two component toner, the cascade developing method, the touch-down developing method, and the cloud developing method. 
   The structure of the charging means described in the foregoing is of a so-called contact type charging method, but a known charging means comprising a tungsten wire, which is enclosed width metal shield of aluminum or the like at three sides. The positive or negative ions generated by the application of a high voltage to the tungsten wire are directed to the surface of the photosensitive drum to uniformly charged the surface, is usable. 
   The charging means may be a roller type as described in the foregoing, a blade type (charging blade), a pad type, a block type, a rod type, a wire type or the like. 
   As for a cleaning method for removing toner remaining on the photosensitive drum, a blade, a fur brush, a magnetic brush or the like is usable. 
   As described in the foregoing, according to the present invention, the reliability of the establishment of electrical connection is carried out between the output electrical contact of the main assembly of the electrophotographic image forming apparatus and the input electrical contact of the process cartridge when the process cartridge is mounted to the main assembly of the apparatus, is improved. 
   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 Applications Nos. 411034/2003 and 352533/2004 filed Dec. 9, 2003 and Dec. 6, 2004, which are hereby incorporated by reference.