Abstract:
A developer cartridge has: a first body having an opening; a memory unit that has a contact terminal, the memory unit is provided at the first body; and a second body that covers the first body, the second body having a exposure hole; wherein the second body and the first body are movable relative to each other, the second body is able to open and close the opening by a relative movement with regard to the first body, and wherein the contact terminal of the memory faces to outside of the developer cartridge through the exposure hole when the second body is positioned at a first position in which the opening is opened, and the contact terminal of the memory unit is covered with the second body when the second body is positioned at a second position and the opening is closed by the second body.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority from Japanese Patent Application No. 2007-061982, which was filed on Mar. 12, 2007, the disclosure of which is herein incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present invention relates to a developer cartridge having a memory chip. 
     BACKGROUND 
     In general, an image forming apparatus such as a laser printer includes a main body, a process cartridge having a developing roller, and a developer cartridge containing a toner. In the image forming apparatus, the developer cartridge can be attached to and detached from the process cartridge and the process cartridge can be attached to and detached from the main body of the apparatus. 
     A memory chip that stores a variety of information relating to the developer cartridge is disposed in the developer cartridge. When the developer cartridge is attached to the image forming apparatus through the process cartridge, the memory chip is electrically connected to a terminal disposed in the image forming apparatus body directly or through a conductive portion disposed in the process cartridge. In this way, the image forming apparatus acquires the variety of information stored in the memory chip. 
     As such a technology, a structure is known in which a panel-like cover covering a contact terminal of a memory chip is rotatably disposed in a developer cartridge (see Patent Document 1). When the developer cartridge is attached to a process cartridge, an end of the cover comes in contact with a part of the process cartridge and the other end of the cover pivots, whereby the contact terminal of the memory chip is exposed and is thus connected to a contact terminal of the process cartridge. According to this structure, since the contact terminal of the memory chip is covered with the cover in a state where the developer cartridge is not attached to the process cartridge, it is possible to prevent contamination or damage of the memory chip. 
     [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2006-221010 
     SUMMARY 
     However, the above-described apparatus disclosed in Patent Document 1 has a following problem. Since a cover should be independent of existing parts (for example, a shutter for opening and closing a toner supply port) in the developer cartridge, there is a problem that the cartridge is complicated. 
     An object of the invention is to provide a developer cartridge which can suppress contamination or damage of a memory chip (memory unit) and which can simplify a configuration thereof. 
     In order to accomplish the above-mentioned object, there is provided a developer cartridge that can be attached to and detached from an image forming apparatus and contains a developer, the developer cartridge comprising: a first body that has an opening for supplying the developer; a memory unit that has a contact terminal, the memory unit is provided at the first body; and a second body that covers the first body, the second body having a exposure hole in which the memory unit can face to outside of the developer cartridge; wherein the second body and the first body are movable relative to each other, the second body is able to open and close the opening by a relative movement with regard to the first body, and wherein the contact terminal of the memory faces to outside of the developer cartridge through the exposure hole when the second body is positioned at a first position in which the opening is opened, and the contact terminal of the memory unit is covered with the second body when the second body is positioned at a second position different from the first position and the opening is closed by the second body. 
     According to a first aspect of the invention, when the opening is closed, the contact terminal of the memory unit is covered with the second body, thereby preventing the contamination or damage thereof. When the opening is opened, the contact terminal of the memory unit is exposed and thus can be connected to a contact terminal disposed at an image forming apparatus. That is, the second body serves as a shutter for opening and closing the opening of the first body as a developer supply port and also serves as a cover for protecting the memory unit. Accordingly, since a cover for protecting the memory unit need not be provided independent of the shutter for opening and closing the developer supply port, it is possible to simplify the device configuration. 
     According to the present invention, since the memory unit is protected by the second body serving as a shutter for opening and closing the opening of the first body, it is possible to prevent the contamination or damage of the memory unit and to simplify the device configuration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Illustrative aspects of the invention will be described in detail with reference to the following figures wherein: 
         FIG. 1  is a side sectional view illustrating a laser printer according to an exemplary embodiment of the invention; 
         FIG. 2  is an exploded perspective view illustrating a developing cartridge and a toner cartridge; 
         FIG. 3  is a cross-sectional view illustrating the developing cartridge and the toner cartridge; 
         FIG. 4A  is a perspective view illustrating the toner cartridge when an inner opening and an outer opening are closed and  FIG. 4B  is a perspective view illustrating the toner cartridge when the inner opening and the outer opening communicate with each other; 
         FIG. 5  is a side view illustrating a relation between an arc-shaped protrusion and an operation lever; 
         FIG. 6A  is an enlarged sectional view illustrating a fixing lever and a locking member before the toner cartridge is fitted to the developing cartridge, and  FIG. 6B  is an enlarged sectional view illustrating the fixing lever and the locking member after the toner cartridge is fitted to the developing cartridge; 
         FIG. 7  is a front view of the toner cartridge; 
         FIG. 8A  is a cross-sectional view illustrating a state where a memory chip is covered with an outer body, and  FIG. 8B  is a cross-sectional view illustrating a state where the memory chip is exposed from an exposure hole; and 
         FIG. 9A  and  FIG. 9B  are perspective views illustrating a toner cartridge and a developing cartridge according to another exemplary embodiment of the invention, where  FIG. 9A  is a perspective view illustrating a state before the toner cartridge is fitted to the developing cartridge and  FIG. 9B  is a perspective view illustrating a state after the toner cartridge is fitted to the developing cartridge. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an exemplary embodiment of the invention will be described in detail with reference to the attached drawings.  FIG. 1  is a side sectional view illustrating a laser printer according to an exemplary embodiment of the invention. In the following description, the entire configuration of a laser printer is first explained in brief and then detailed features of the invention will be explained. In the following description, directions are based on a user using a laser printer  1 . That is, in  FIG. 1 , the right side is defined as a “near side”, the left side is defined as a “far side”, the far side in the direction perpendicular to the sheet surface is defined as a “right side”, and the near side in the direction perpendicular to the surface or the fig sheet is defined as a “left side.” Since the vertical direction shown in the figures is equal to the vertical direction at the time when the user uses the apparatus, the vertical direction is defined as a “vertical direction.” 
     &lt;Entire Configuration of Laser Printer&gt; 
     As shown in  FIG. 1 , a laser printer  1  as an example of the image forming apparatus includes a feeder unit  4  that feeds a sheet  3  into a main casing  2  as an example of a main body of the apparatus and an image forming unit  5  that forms an image on the fed sheet  3 . 
     &lt;Configuration of Feeder Unit&gt; 
     The feeder unit  4  includes a sheet feeding tray  6  that is detachably attached to the bottom of the main casing  2  and a sheet pressing plate  7  that is disposed in the sheet feeding tray  6 . The feeder unit  4  further includes various rollers  11  that conveys the sheet  3  or removes sheet powders. 
     In the feeder unit  4  having the above-mentioned configuration, the sheet  3  in the sheet feeding tray  6  is sent to the upper side of the sheet pressing plate  7  and is conveyed to the image forming unit  5  by the various rollers  11 . 
     &lt;Configuration of Image Forming Unit&gt; 
     The image forming unit  5  includes a scanner unit  16 , a process cartridge  17 , and a fixing unit  18 . 
     &lt;Configuration of Scanner Unit&gt; 
     The scanner unit  16  is disposed in the upper portion of the main casing  2  and includes a laser-emitting portion (not shown), a polygon mirror  19  that is rotationally driven, lenses  20  and  21 , and reflecting mirrors  22 ,  23 , and  24 . A laser beam based on image data and emitted from the laser-emitting portion is transmitted or reflected by the polygon mirror  19 , the lens  20 , the reflecting mirror  22 , the reflecting mirror  23 , the lens  21 , and the reflecting mirror  24  in this order as indicated by a dotted line and then is applied to the surface of a photosensitive drum  27  of the process cartridge  17  at a high speed. 
     &lt;Configuration of Process Cartridge&gt; 
     The process cartridge  17  is detachably attached to the main casing  2  when a front cover  2   a , which is disposed in the front of the main casing  2 , opens. The process cartridge  17  includes a developing cartridge  28  and a drum unit  51 . 
     The developing cartridge  28  can be attached to and detached from the main casing  2  in a state where it is fitted to the drum unit  51 . The developing cartridge  28  may be freely attached to and detached from the drum unit  51  fixed to the main casing  2 . 
     The developing cartridge  28  includes a toner cartridge  100  that can be attached to and detached from the developing cartridge, a developing roller  31 , a thickness regulating blade  32 , and a supply roller  33 . A toner in the toner cartridge  100  is agitated by an agitator  100   a  and is then supplied to the developing roller  31  by the supply roller  33 . At this time, the toner is frictionally charged positive between the supply roller  33  and the developing roller  31 . The toner supplied to the developing roller  31  enters between the thickness regulating blade  32  and the developing roller  31  and is held as a thin layer having a constant thickness on the developing roller  31 , with the rotation of the developing roller  31 . 
     The drum unit  51  includes a photosensitive drum  27 , a scorotron charging unit  29 , and a transfer roller  30 . 
     The photosensitive drum  27  is rotatably supported in the body of the drum unit  51 . 
     The scorotron charging unit  29  is a positive scorotron charging unit for generating a corona discharge from a charging wire made of tungsten or the like and serves to charge the surface of the photosensitive drum  27  to be uniformly positive. 
     The transfer roller  30  is disposed below the photosensitive drum  27  so as to come in opposed contact with the photosensitive drum  27 . And the transfer roller  30  is rotatably supported in the body of the drum unit  51 . A transfer bias is applied to the transfer roller  30  based on the static current control at the time of transfer. 
     The surface of the photosensitive drum  27  is uniformly charged positive by the scorotron charging unit  29  and then is exposed to a laser beam from the scanner unit  16  at a high speed. Accordingly, the potential of the exposed portion is lowered to form an electrostatic latent image based on image data. Here, the “electrostatic latent image” means an exposed portion which is exposed to the laser beam and is lowered in potential on the surface of the photosensitive drum  27  uniformly charged positive. And, with the rotation of the developing roller  31 , the toner held on the developing roller  31  is supplied to the electrostatic latent image formed on the surface of the photosensitive drum  27  at the time of coming in contact with the photosensitive drum  27 . The toner is selectively held on the surface of the photosensitive drum  27  and is visualized, thereby forming a toner image by an inversion phenomenon. 
     Thereafter, the photosensitive drum  27  and the transfer roller  30  are rotationally driven to convey a sheet  3  therebetween. By conveying the sheet  3  between the photosensitive drum  27  and the transfer roller  30 , the toner image held on the surface of the photosensitive drum  27  is transferred to the sheet  3 . 
     &lt;Configuration of Fixing Unit&gt; 
     The Fixing unit  18  is disposed on the downstream side of the process cartridge  17  and includes a heating roller  41  and a pressing roller  42  that is opposed to the heating roller  41  so as to press the heating roller  41 . The fixing unit  18  thermally fixes the toner transferred to the sheet  3  while the sheet  3  passes between the heating roller  41  and the pressing roller  42 . The sheet  3  thermally fixed by the fixing unit  18  is conveyed to the discharge roller  45  disposed on the downstream side of the fixing unit  18  and is sent to a sheet discharging tray  46  by the discharge roller  45 . 
     &lt;Detailed Structure of Toner Cartridge&gt; 
     Next, the detailed structure of a toner cartridge  100  as an example of the developer cartridge according to the invention will be described. In the drawings,  FIG. 2  is an exploded perspective view illustrating the developing cartridge and the toner cartridge and  FIG. 3  is a sectional view illustrating the developing cartridge and the toner cartridge.  FIG. 4A  is a perspective view illustrating the toner cartridge when an inner opening and an outer opening are closed and  FIG. 4B  is a perspective view illustrating the toner cartridge when the inner opening and the outer opening communicate with each other.  FIG. 5  is a side view illustrating a relation between an arc-shaped protrusion and an operation lever.  FIG. 6A  is an enlarged sectional view illustrating a fixing lever and a locking member before the toner cartridge is fitted to the developing cartridge and  FIG. 8B  is an enlarged sectional view illustrating the fixing lever and the locking member after the toner cartridge is fitted to the developing cartridge.  FIG. 7  is a front view of the toner cartridge.  FIG. 8A  is a cross-sectional view illustrating a state where a memory chip is covered with an outer body and  FIG. 8B  is a cross-sectional view illustrating a state where the memory chip is exposed from an exposure hole. 
     As shown in  FIG. 2 , the toner cartridge  100  constitutes a process cartridge  17  along with the developing cartridge  28  and the drum unit  51  and is detachably attached to the main casing  2  in a state where it is attached to the developing cartridge  28 . Specifically, as shown in  FIG. 3 , the toner cartridge  100  includes an inner body  101  that contains a toner T, an outer body  102  that is movable relative to the inner body  101 , and a memory chip  103  as an example of memory means fixed to the outer circumferential surface of the inner body  101 . Here, the memory chip  103  stores a variety of information such as an amount of toner contained in the toner cartridge  100 . The variety of information is read by a reading device disposed in the main casing  2  and is used to perform various control operations for the laser printer  1 . 
     The inner body  101  is formed in a hollow cylinder shape and is rotatably supported by a cylindrical inner circumferential surface of the outer body  102 . An inner opening  101   a  for supplying the toner T to the developing cartridge  28  is formed at a far position on a cylindrical outer circumferential surface of the inner body  101 . As shown in  FIG. 4B , three inner openings  101   a  are disposed with a predetermined gap in the axis direction of the inner body  101  and the inner opening  101   a  located at the center thereof is longer in the axis direction than the inner openings  101   a  located at both sides. 
     A pair of shutter engaging protrusions  101   b  protruding externally in the diameter direction is formed at one end and the other end of the outer circumferential surface of the inner body  101 . As shown in  FIG. 3 , the shutter engaging protrusions  101   b  engage with engaging portions  28   c  so as to interpose a pair of engaging portions  28   c , which is formed in a shutter  28   b  for opening and closing a toner supply hole  28   a  of the developing cartridge  28 , therebetween in the rotation direction when the toner cartridge  100  is attached to the developing cartridge  28 . 
     A seat portion  101   c  for fixing the memory chip  103  is formed at a front-lower position on the cylindrical outer circumferential surface of the inner body  101 . That is, the memory chip  103  fixed to the seat portion  101   c  is disposed to be opposite to the inner opening  101   a  with a center axis CA of the inner body  101  interposed therebetween in a direction D connecting the center C of the inner opening  101   a  and the center axis CA of the inner body  101  among the diameter directions of the inner body  101 . The seat portion  101   a  is formed at the same position in the axis direction (width direction) of the inner body  101  as an exposure hole  102   c  (see  FIG. 2 ) formed in the outer body  102 . 
     As shown in  FIG. 2 , arc-shaped protrusions  101   d  (only one is shown) protruding externally in the axis direction are formed at both ends of the inner body  101 . The arc-shaped protrusions  101   d  are inserted into concave portions  28   e  of an operation lever  28   d  disposed pivotally in the developing cartridge  28  when the toner cartridge  100  is attached to the developing cartridge  28 . Accordingly, as shown in  FIG. 5 , by allowing the operation lever  28   d  engaging with the arc-shaped protrusions  101   d  to pivot in the circumferential direction, the inner body  101  rotates relative to the outer body  102 . 
     The outer body  102  is formed in a hollow cylinder shape and outer openings  102   a  that can communicate with the inner openings  101   a  of the inner body  101  are formed in far positions on a cylindrical outer circumferential wall, as shown in  FIG. 3 . As shown in  FIG. 4B , three outer openings  102   a  are disposed in parallel in the axis direction to correspond to three inner openings  101   a  disposed in parallel in the axis direction. 
     A pair of longitudinal grooves  102   b  engaging with the pair of shutter engaging protrusions  101   b  formed at both ends of the inner body  101  to be slidable in the circumferential direction is formed at both ends on the outer circumferential wall of the outer body  102 . Arc shaped longitudinal grooves  102   d  (only one is shown) engaging with the arc-shaped protrusions  101   d  of the inner body  101  so as to be slidable in the circumferential direction are formed at both ends of the outer body  102 . Since the longitudinal grooves  102   b  and the arc-shaped longitudinal grooves  102   d  are formed with a predetermined length, the inner body  101  is rotatable relative to the outer body  102  by the predetermined length. 
     A drive delivery portion  100   c , which is fixed to the left end of the rotation shaft  100   b  of the agitator  100   a  disposed to be rotatable relative to the inner body  101  and the outer body  102 , is disposed on the left end surface of the outer body  102 . When power is delivered to the drive delivery portion  100   c  from the main casing  2 , the agitator  100   a  rotates. 
     As shown in  FIG. 2 , a grip portion  102   e , a fixing lever  104 , and a memory receiving room  102   f  are disposed on the front side of the outer circumferential surface of the outer body  102 . The grip portion  102   e  is a portion gripped by a user and protrudes forward from the center in the axis direction of the outer body  102 . 
     As shown in  FIG. 5 , the fixing lever  104  is disposed below the grip portion  102   e  and the upper end thereof is rotatably supported by the grip portion  102   e , whereby the lower end of the fixing lever  104  can pivot forward and backward. An operation piece  104   a  extending to the front along the grip portion  102   e  is formed in the upper end of the fixing lever  104 . An engaging claw  104   b  protruding to the far side is formed at the lower end of the fixing lever  104 . The engaging claw  104   b  of the fixing lever  104  is always biased to the far side by a spring. Accordingly, when the toner cartridge  100  is attached to the developing cartridge  28 , the engaging claw  104   b  is hooked to an engaging portion  28   f  formed in the developing cartridge  28 , whereby the toner cartridge  100  is fixed to the developing cartridge  2 S. Specifically, the fixation of the toner cartridge  100  is realized, as shown in  FIG. 2 , by allowing a positioning pin  100   d  formed in the far-up side of the toner cartridge  100  to engage with a positioning concave portion  28   g  of the developing cartridge  28 , as well as by hooking the engaging claw  104   b  to the engaging portion  28   f.    
     As shown in  FIG. 6A , a locking member  105  that release or locks the relative movement between the inner body  101  and the outer body  102  is disposed inside the lower end of the fixing lever  104 . Specifically, an end of the locking member  105  is integrally formed with (or fixed to) the inner edge of a through hole  102   h  formed in the front-down side of the outer body  102  and thus the locking member can warp in the diameter direction of the outer body  102 . A locking piece  105   a  protruding inward in the diameter direction of the outer body  102  is formed at the other end of the locking member  105 . By allowing the locking piece  105   a  to engage with an engaging concave portion  101   e  formed at a corresponding position of the inner body  101 , the relative movement between the inner body  101  and the outer body  102  is locked. 
     A release piece  105   b  protruding outward (downward) in the diameter direction from the outer circumferential surface of the outer body  102  is formed at the other end of the locking member  105 . When the toner cartridge  100  is attached to the developing cartridge  28 , the release piece  105   b  comes in contact with a stopper  28   h  formed in the developing cartridge  28  and is pushed outward in the diameter direction of the outer body  102 . Accordingly, the locking piece  105   a  is pulled out of the engaging concave portion  101   e  of the inner body  101 . 
     As shown in  FIG. 7 , the memory receiving room  102   f  is disposed on the right side of the grip portion  102   e . As shown in  FIG. 3 , the memory receiving room  102   f  is defined by a swelling wall  102   g  of the outer body  102  swelling to the front side and the lower side and an outer circumferential wall of the inner body  101 . The exposure hole  102   c  for exposing externally the memory chip  103  is formed through the front wall of the swelling wall  102   g . As shown in  FIG. 7 , since the memory receiving room  102   f  is disposed on the right side of the grip portion  102   e , the exposure hole  102   c  is disposed at a position deviating in the axis direction of the outer body  102 , that is, in the width direction (lateral width direction) of the outer body  102 , from the grip portion  102   e.    
     The lateral width and the longitudinal width of the exposure hole  102   c  have magnitudes corresponding to the lateral width and the longitudinal width of two wire-shaped terminals  2   b  disposed in the main casing  2  shown in  FIG. 1 . Here, “magnitudes corresponding to the lateral width and the longitudinal width of two wire-shaped terminals  2   b ” means magnitudes in which clearance of about 2 mm is considered with respect to the lateral width and the longitudinal width of the terminals  2   b.    
     As shown in  FIG. 3 , a sponge-like sealing member $ for suppressing the movement of the toner from the inner opening  101   a  to the memory chip  103  is disposed below the memory receiving room  102   f , that is, between the lower wall of the swelling wall  102   g  and the inner body  101 . 
     The memory chip  103  is fixed to the seat portion  101   c  of the inner body  101  in a state where the contact  103   a  thereof. Races the outside in the diameter direction of the inner body  101 . Accordingly, the contact terminal  103   a  of the memory chip  103  is covered with the outer body  102 , as shown in  FIG. 8A , when the inner opening  101   a  and the outer opening  102   a  are closed. And, as shown in  FIG. 8B , the contact terminal  103   a  is exposed externally from the exposure hole  102   c , when the inner opening  101   a  and the outer opening  102   a  communicate with each other. As shown in  FIG. 7 , the memory chip  103  is disposed at the right end of the rotation shaft  100   b , while the drive delivery portion  100   c  is disposed at the left end of the rotation shaft  100   b  of the agitator  100   a . Accordingly, vibration of the drive delivery portion  100   c  is hardly transmitted to the memory chip  103 . 
     Next, a method of attaching the toner cartridge  100  to the developing cartridge  28  and a method of attaching the developing cartridge  28  to the main casing  2  will be described. 
     First, as shown in  FIG. 3 , the toner cartridge  100  is attached to the front portion of the developing cartridge  28  while the positioning pin  100   d  of the toner cartridge  100  is positioned to the positioning concave portion  28   g  of the developing cartridge  28 . At this time, as shown in  FIG. 6 , by hooking the engaging claw  104   b  of the fixing lever  104  to the engaging portion  28   f  of the developing cartridge  28 , the toner cartridge  100  is fixed to the developing cartridge  28 . 
     By allowing the release piece  105   b  of the locking member  105  to engage with the stopper  28   h  of the developing cartridge  28 , the locking piece  105   a  is pulled out of the engaging concave portion  101   e  of the inner body  101  and thus the inner body  101  can be rotatable relative to the outer body  102 . As shown in  FIG. 8A , the arc-shaped protrusions  101   d  formed at the ends of the inner body  101  enter the concave portions  28   e  of the operation lever  28   d  of the developing cartridge  28  and the shutter engaging protrusion  101   b  formed in the far upper portion on the outer circumferential surface of the inner body  101  engages with the shutter  28   b  of the developing cartridge  28 . 
     As shown in  FIG. 8B , when the operation lever  28   d  of the developing cartridge  28  is made to pivot upward after the toner cartridge  100  is attached to the developing cartridge  28  in the above-mentioned way, the inner body  101  and the shutter  28   b  rotate together relative to the outer body  102 . Accordingly, the inner opening  101   a , the outer opening  102   a , a shutter opening  28   j , and the toner supply hole  28   a  communicate with one another and the memory chip  103  is thus exposed externally from the exposure hole  102   c.    
     Thereafter, as shown in  FIG. 1 , the developing cartridge  28  mounted with the toner cartridge  100  is inserted into the main casing  2  and is attached to the drum unit  51  fitted to the main casing  2 . At this time, the developing cartridge  28  is guided by a guide portion of the main casing  2  so that it is maintained in a horizontal posture up to a predetermined position and then the front portion thereof goes down after the predetermined position. In this way, the developing cartridge is attached to the main casing  2 . When the developing cartridge  28  has been attached, the terminal  2   b  disposed in the main casing  2  enters the toner cartridge  100  through the exposure hole  102   c  (see  FIG. 3 ) and comes in contact with the memory chip  103 . 
     According to the above-mentioned embodiment, the following advantages can be obtained. 
     Since the memory chip  103  is protected by the outer body  102  serving as a shutter for opening and closing the inner opening  101   a  of the inner body  101 , it is possible to suppress the contamination or damage of the memory chip  103  and to further simplify the device configuration. 
     When the inner opening  101   a  and the outer opening  102   a  are closed, the contact  103   a  of the memory chip  103  is electrically disconnected from the terminal  2   b  of the main casing  2  and thus the laser printer  1  does not work, thereby urging a user to raise the operation lever  28   d . That is, since the information of the memory chip  103  can be read by the laser printer  1  after the inner opening  101   a  and the outer opening  102   a  have communicated with each other so as to supply the toner from the toner cartridge  100  to the developing cartridge  28 , it is possible to suppress an erroneous operation of the laser printer  1 . 
     The memory chip  103  is disposed to be opposite to the inner opening  101   a  with the center axis CA of the inner body  101  in the direction D shown in  FIG. 3 . Accordingly, even when the toner leaks between the inner body  101  and the outer body  102 , the toner hardly reaches the memory chip  103  apart from the inner opening  101   a , thereby preventing the contamination of the memory chip  103 . 
     Since the sealing member S is disposed between the inner body  101  and the outer body  102 , it is possible to further prevent the contamination of the memory chip  103  due to the toner. 
     The exposure hole  102   c  is disposed at a position deviating in the axis direction of the outer body  102  from the grip portion  102   e . Accordingly, even when the exposure hole  102   c  is greater than a user&#39;s finger, the user&#39;s finger is prevented from coming in contact with the memory chip  103  at the time of the user gripping the grip portion  102   e , thereby preventing the contamination of the memory chip  103 . 
     Since the locking member  105  for releasing or locking the relative rotation between the inner body  101  and the outer body  102  is disposed, the leakage of a toner is prevented due to the communication of the inner opening  101   a  and the outer opening portion  102   a  with each other in the toner cartridge  100  in a single product state. 
     Since the drive delivery portion  100   c  is disposed at the left end of the rotation shaft  100   b  of the agitator  100   a  and the memory chip  103  is disposed at the right end of the rotation shaft  100   b , the vibration of the drive delivery portion  100   c  is hardly transmitted to the memory chip  103 , thereby elongating the lifetime of the memory chip  103 . 
     Since the width of the exposure hole  102   c  corresponds to the width of the terminal  2   b  which is generally smaller than a human finger, the user&#39;s finger does not come in contact with the contact  103   a  of the memory chip  103  through the exposure hole  102   c , thereby preventing the contamination of the memory chip  103 . 
     The invention is not limited to the above-mentioned embodiment, but may be modified in various forms as described below. 
     Although it has been described in the embodiment that the toner cartridge  100  is attached to the main casing  2  in a state where the developing cartridge  28  and the drum unit  51  is incorporated into a bundle, the invention is not limited to the configuration. For example, when the parts of the developing cartridge  28  are fixed to the main casing  2 , the toner cartridge  100  may be attached directly to the main casing  2 . 
     Although it has been described in the embodiment that the developing cartridge  28  can be freely attached to and detached from the drum unit  51 , the developing cartridge  28  and the drum unit  51  may be formed in a bundle (not detachable). 
     Although it has been described in the embodiment that the attachment direction of the toner cartridge  100  is set to the diameter thereof, the invention is not limited to it. For example, as shown in  FIGS. 9A and 9B , the attachment direction of a toner cartridge  100 ′ may be set to the axis direction. In this case, a memory chip may be covered with an outer body  102 ′ or may be exposed from an exposure hole  102   c ′ of the outer body  102 ′. In this case, the grip portion  102   e  and the fixing lever  104  provided in the embodiment are not necessary. In the toner cartridge  100 ′, only by disposing a locking piece  110  locked to a part of a developing cartridge  28 ′ on a part of the outer circumferential surface of the cylinder shape thereof, the outer body  102 ′ can be made not to be movable relative to the developing cartridge  28 ′ In this case, an operating portion  120  for allowing an inner body to rotate relative to the outer body  102 ′ is disposed in an end surface of the outer body  102 ′. Accordingly, the structure for rotating the inner body can be more simplified than the above-mentioned embodiment, thereby reducing the manufacturing cost. 
     Although it has been described in the embodiment that the inner body  101  and the outer body  102  are formed in a hollow cylinder shape and the inner body  101  rotates relative to the outer body  102 , the invention is not limited to it. For example, the inner body and the outer body may be both in a hollow rectangular shape and the inner body and the outer body may be made to move relative to each other along a predetermined side thereof. 
     Although it has been described in the above-mentioned embodiment that the inner body  101  is made to rotate relative to the outer body  102  fixed to the developing cartridge  28 , the invention is not limited to it. On the contrary, the inner body  101  may be fixed to the developing cartridge  28  and the outer body  102  may be made to rotate relative to the inner body  101 . 
     Although the invention has been applied to the laser printer  1  in the above-mentioned embodiment, the invention is not limited to it, but the invention may be applied to other image forming apparatus such as copiers or multi-function device. 
     Although it has been described in the above-mentioned embodiment that the toner cartridge  100  contains a positively-charging developer, the toner cartridge may contain a negatively-charging developer.