Patent Publication Number: US-2022229394-A1

Title: Drum cartridge including electrical contact surface positioned at outer surface of drum frame

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation application of U.S. Ser. No. 17/105,723, filed Nov. 27, 2020, which is a continuation of U.S. application Ser. No. 16/560,333, filed Sep. 4, 2019, which is a continuation of International Application No. PCT/JP2017/023028 filed Jun. 22, 2017, which claims priority from Japanese Patent Application No. 2017-042646 filed Mar. 7, 2017. The entire contents of the earlier applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a drum cartridge and a process cartridge. 
     BACKGROUND 
     Conventionally, there has been known a process cartridge detachably attachable to an electro-photographic image-forming apparatus, such as an LED printer. Suh a process cartridge includes a developing cartridge and a drum cartridge. The developing cartridge includes a developing roller, while the drum cartridge includes a photosensitive drum. Upon attachment of the developing cartridge to the drum cartridge, a peripheral surface of the developing roller faces a peripheral surface of the photosensitive drum. 
     For example, Japanese Patent Application Publication No. 2008-249802 discloses a process cartridge configured of a developing cartridge and a drum cartridge. 
     SUMMARY 
     Further, conventionally, there is also known a developing cartridge including a storage medium. The storage medium may be an IC chip, for example. In the storage medium, various kinds of information relating to the developing cartridge may be stored. In recent years, image-forming apparatuses may deal with a lot of information not only relating to developing cartridges, but also relating to drum cartridges. Hence, there is an increasing demand that a storage medium be mounted in a drum cartridge. However, upon attachment of a developing cartridge to a frame (drum frame) of a drum cartridge, part of an outer surface of the drum frame may be covered by the attached developing cartridge. 
     In view of the foregoing, it is an object of the disclosure to provide a structure that allows an electrical contact surface of a storage medium can contact a terminal of an image-forming apparatus even in a state where the storage medium is disposed on an outer surface of a drum frame and a developing cartridge is attached to the drum frame. 
     In order to attain the above and other objects, according to a first aspect of the present disclosure, there is provided a drum cartridge including a drum frame, a photosensitive drum, and a first storage medium. A developing cartridge is detachably attachable to the drum frame. The drum frame has one end portion and another end portion spaced apart from the one end portion in a first direction. The photosensitive drum is rotatable about a first axis extending in a second direction. The photosensitive drum is positioned at the one end portion. The first storage medium has a first electrical contact surface. The first storage medium is positioned at an outer surface of the drum frame, the outer surface being exposed in a state where the developing cartridge is attached to the drum frame. 
     According to a second aspect of the present disclosure, there is provided a process cartridge including: the above drum cartridge according to the first aspect; and a developing cartridge. The developing cartridge includes: a casing configured to store toner, the casing having one end portion and another end portion spaced apart from the one end portion in the first direction; a developing roller rotatable about a second axis extending in the second direction and positioned at the one end portion of the casing in the first direction; and a second storage medium having a second electrical contact surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1  is a perspective view of a process cartridge according to one embodiment; 
         FIG. 2  is a perspective view of a drum cartridge of the process cartridge according to the embodiment; 
         FIG. 3  is another perspective view of the drum cartridge of the process cartridge according to the embodiment; 
         FIG. 4  is an exploded perspective view of the drum cartridge of the process cartridge according to the embodiment; 
         FIG. 5  is an external view of an IC chip of the drum cartridge of the process cartridge according to the embodiment; 
         FIG. 6  is a plan view of the drum cartridge according to the embodiment as viewed from a side of a drum bottom wall; 
         FIG. 7  is a plan view of the drum cartridge according to the embodiment as viewed from a side opposite the side of the drum bottom wall; 
         FIG. 8  is a plan view of the process cartridge according to the embodiment as viewed from a side of a first connecting plate (one side in a first direction); 
         FIG. 9  is a plan view of the process cartridge according to the embodiment as viewed from a side of a second connecting plate (another side in the first direction); 
         FIG. 10  is a plan view of the process cartridge according to the embodiment as viewed from a side of a first drum side plate (one side in a second direction); 
         FIG. 11  is a plan view of the process cartridge according to the embodiment as viewed from a side of a second drum side plate (another side in the second direction); 
         FIG. 12  is a perspective view of a developing cartridge of the process cartridge according to the embodiment according to the embodiment; and 
         FIG. 13  is another perspective view of the developing cartridge of the process cartridge according to the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, one embodiment of the present disclosure will be described with reference to the accompanying drawings. 
     In the following description, a direction connecting a handle and a photosensitive drum of a drum cartridge will be referred to as “first direction.” Further, a direction in which a rotational axis of the photosensitive drum extends will be referred to as a “second direction.” Further, a direction crossing a drum bottom plate will be referred to as “third direction.” In the embodiment described below, the first direction and the second direction cross each other (preferably, orthogonal to each other); the second direction and the third direction cross each other (preferably, orthogonal to each other); and the third direction and the first direction cross each other (preferably, orthogonal to each other). 
     1. Process Cartridge 
       FIG. 1  is a perspective view illustrating a state where a developing cartridge  1  is attached to a drum cartridge  2 . Hereinafter, a cartridge in which the developing cartridge  1  is attached to the drum cartridge  2  will be referred to as a process cartridge  100 . The process cartridge  100  is a replaceable unit configured to be used in an electrophotographic-type image-forming apparatus. A later printer or an LED printer is an example of such an electrophotographic-type image-forming apparatus. The image-forming apparatus includes a frame for retaining the process cartridge  100 . The process cartridge  100  is attachable to and detachable from the frame of the image-forming apparatus. Incidentally, the process cartridge  100  is prepared for toner of each color. For example, in case of an image-forming apparatus using four colors of toner, four of the process cartridges  100  are attached individually. 
     As illustrated in  FIG. 1 , the process cartridge  100  includes the developing cartridge  1  and the drum cartridge  2 . The developing cartridge  1  is attachable to and detachable from the drum cartridge  2 . Hence, only one of the developing cartridge  1  and drum cartridge  2  can be replaced with a new one. With this structure, a user of the image-forming apparatus can effectively consume a service life of the developing cartridge  1  and a service life of the drum cartridge  2 , individually. 
     2. Drum Cartridge 
     2-1. Structure of the Drum Cartridge 
       FIGS. 2 and 3  are perspective views of the drum cartridge  2 .  FIG. 4  is a exploded perspective view of the drum cartridge  2 . The drum cartridge  2  is configured to transfer the toner supplied from the developing cartridge  1  onto printing sheets via a photosensitive drum  22 . As illustrated in  FIGS. 2-4 , the drum cartridge  2  of the present embodiment includes a drum frame  21 , the photosensitive drum  22 , a transfer roller  23 , a conveying roller  24 , a gear portion  25 , a charging device  26 , a first pressing member  27  and a second pressing member  28 . 
     The drum frame  21  is a frame to which the developing cartridge  1  is attachable. As illustrated in  FIG. 4 , the drum frame  21  of the present embodiment is configured of two members, i.e., a frame main body  31 , and a frame cover  32 . The frame cover  32  is fixed to the frame main body  31 . The photosensitive drum  22  and transfer roller  23  are positioned between the frame main body  31  and frame cover  32 . Incidentally, the drum frame  21  may be configured of a single member, or three or more different members. 
     As illustrated in  FIGS. 2 and 3 , the drum frame  21  has one end portion  211  in the first direction, and another end portion  212  spaced away from the one end portion  211  in the first direction. The one end portion  211  is closer to the photosensitive drum  22  than the another end portion  212  is to the photosensitive drum  22 . The drum frame  21  has a recessed portion  210  for receiving the developing cartridge  1  between the one end portion  211  and another end portion  212 . 
     The drum frame  21  includes a first drum side plate  41 , a second drum side plate  42 , a first connecting plate  43 , a second connecting plate  44 , and a drum bottom plate  45 . 
     The first drum side plate  41  is positioned at one end of the drum frame  21  in the second direction. The first drum side plate  41  extends in the first direction and third direction. In a state where the developing cartridge  1  is attached to the drum frame  21 , the first drum side plate  41  covers part of a gear cover  152  (described later) of the developing cartridge  1 . Also, in the state where the developing cartridge  1  is attached to the drum frame  21 , the first drum side plate  41  faces a first developing side plate  111  (described later) of the developing cartridge  1  in the second direction. The first drum side plate  41  has a first guide groove  411 . In a state where the developing cartridge  1  is attached to the drum cartridge  2 , one end of a developing-roller shaft  132  (described later) in the second direction is fitted in the first guide groove  411 . 
     The second drum side plate  42  is positioned at another end of the drum frame  21  in the second direction. The second drum side plate  42  extends in the first direction and third direction. The first drum side plate  41  and second drum side plate  42  are spaced apart from each other in the second direction. The photosensitive drum  22  and transfer roller  23  are positioned between the first drum side plate  41  and second drum side plate  42 . In the state where the developing cartridge  1  is attached to the drum cartridge  2 , the second drum side plate  42  covers part of an outer surface of a second developing side plate  112  of a casing  11  (described later). Further, in the state where the developing cartridge  1  is attached to the drum frame  21 , the second drum side plate  42  faces the second developing side plate  112  of the developing cartridge  1  in the second direction. The second drum side plate  42  has a second guide groove  421 . In the state where the developing cartridge  1  is attached to the drum cartridge  2 , another end of the developing-roller shaft  132  in the second direction is fitted in the second guide groove  421 . 
     The first connecting plate  43  is positioned at the one end portion  211  of the drum frame  21  in the first direction. The first connecting plate  43  extends in the second direction between one end portion of the first drum side plate  41  in the first direction and one end portion of the second drum side plate  42  in the first direction. The one end portion of the first drum side plate  41  in the first direction and the one end portion of the second drum side plate  42  in the first direction are connected to each other by the first connecting plate  43 . Part of an outer peripheral surface of the photosensitive drum  22  is covered by the first connecting plate  43 . In the present embodiment, part of the frame main body  31  and part of the frame cover  32  constitute the first connecting plate  43 . Incidentally, the first connecting plate  43  may be configured of a single member. 
     The second connecting plate  44  is positioned at the another end portion  212  of the drum frame  21  in the first direction. The second connecting plate  44  extends in the second direction between another end portion of the first drum side plate  41  in the first direction and another end portion of the second drum side plate  42  in the first direction. The another end portion of the first drum side plate  41  in the first direction and the another end portion of the second drum side plate  42  in the first direction are connected to each other by the second connecting plate  44 . The photosensitive drum  22  and transfer roller  23  are positioned between the first connecting plate  43  and second connecting plate  44 . 
     The second connecting plate  44  includes a handle  441 . That is, the drum frame  21  includes the handle  441  on an outer surface of the another end portion  212  in the first direction. The user of the image-forming apparatus grasps this handle  441  at the time of attachment and detachment of the process cartridge  100  relative to the image-forming apparatus. 
     The drum bottom plate  45  extends in the first direction and the second direction between the first drum side plate  41  and the second drum side plate  42  and between the first connecting plate  43  and second connecting plate  44 . The first drum side plate  41  and second drum side plate  42  are connected to each other by the drum bottom plate  45 . The drum bottom plate  45  has a conveyor opening  451  and a first opening  452 . 
     The conveyor opening  451  is an opening that penetrates the drum bottom plate  45  in the third direction. The conveyor opening  451  is positioned between the transfer roller  23  and conveying roller  24  in the first direction. The drum bottom plate  45  also includes a plurality of guide ribs  453  protruding toward the inside of the conveyor opening  451 . A printing sheet conveyed by the conveying roller  24  is configured to be guided to the conveyor opening  451 , while being in contact with the guide ribs  453 . After passing through the conveyor opening  451 , the printing sheet is inserted into a position between the photosensitive drum  22  and transfer roller  23 . 
     The first opening  452  is an opening penetrating the drum bottom plate  45  in the third direction. The first opening  452  is positioned between the conveyor opening  451  and the first drum side plate  41 . The conveyor opening  451  and first opening  452  are positioned adjacent to each other in the second direction. In the state where the developing cartridge  1  is attached to the drum frame  21 , an electrical contact surface  181  of an IC chip  18  (described later) mounted on the developing cartridge  1  is exposed through the first opening  452 . Accordingly, the electrical contact surface  181  can make contact with an electrical terminal (not shown) of the image-forming apparatus without being interrupted by the drum bottom plate  45 . 
     The drum bottom plate  45  also includes a notch  454  connected to the first opening  452 . The notch  454  is depressed in the first direction from the first opening  452  toward the gear portion  25  (described later). In the state where the developing cartridge  1  is attached to the drum cartridge  2 , a protrusion  153  of the gear cover  152  (described later) of the developing cartridge  1  is fitted in the notch  454 . With this structure, the electrical contact surface  181  can be fixed in position relative to the first opening  452 . 
     The photosensitive drum  22  is rotatable about a rotational axis (first axis) extending in the second direction. The photosensitive drum  22  is positioned at the one end portion  211  of the drum frame  21  in the first direction. The photosensitive drum  22  is disposed along the first connecting plate  43 . Upon attachment of the developing cartridge  1  to the drum cartridge  2 , an outer peripheral surface of a developing roller  13  (described later) and the outer peripheral surface of the photosensitive drum  22  contact each other. 
     The photosensitive drum  22  of the present embodiment includes a drum main body  221  and a drum shaft  222 . The drum main body  221  is a cylindrical-shaped member extending in the second direction. The drum main body  221  has an outer peripheral surface covered with a photosensitive material. The drum shaft  222  is a columnar-shaped member extending in the second direction along the rotational axis of the photosensitive drum  22 . The drum shaft  222  is inserted in a through-hole formed in a center of the drum main body  221 . The drum main body  221  is fixed to the drum shaft  222  so as not to rotate relative to the drum shaft  222 . 
     The drum shaft  222  has one end in the second direction fixed to a drum gear  251 . The drum gear  251  belongs to the gear portion  25  (described later). The drum gear  251  is rotatable about the first axis. The drum shaft  222  and drum main body  221  are thus rotatable when driven by the gear portion  25 . Incidentally, the drum shaft  222  may not penetrate the drum main body  221  in the second direction. For example, a pair of drum shafts  222  may be provided each at each end of the drum main body  221  in the second direction to extend outward therefrom in the second direction. 
     As a material for the drum shaft  222 , an electrically conductive member, such as metal, may be employed. The drum shaft  222  is connectable to a ground terminal of the image-forming apparatus. With this configuration, the drum shaft  222  can be maintained at a reference voltage. 
     The transfer roller  23  is a roller rotatable about a rotational axis (transfer-roller axis) extending in the second direction. The transfer roller  23  is positioned at the one end portion  211  of the drum frame  21  in the first direction. The transfer roller  23  is disposed along the first connecting plate  43 . An outer peripheral surface of the transfer roller  23  is in contact with the outer peripheral surface of the photosensitive drum  22 . While a printing sheet passes between the photosensitive drum  22  and transfer roller  23 , the transfer roller  23  presses the printing sheet against the outer peripheral surface of the photosensitive drum  22 . Through this operation, toner adhered to the peripheral surface of the photosensitive drum  22  is transferred onto the printing sheet. 
     As described above, the drum cartridge  2  of the present embodiment includes the transfer roller  23 . Hence, replacement of the transfer roller  23  can be accomplished along with replacement of the drum cartridge  2 . 
     The conveying roller  24  is a roller rotatable about a rotational axis (conveying-roller axis) extending in the second direction. The conveying roller  24  is disposed along the conveyor opening  451 . The photosensitive drum  22  and the conveying roller  24  are disposed to be spaced apart from each other in the first direction and to be in parallel to each other. The transfer roller  23  and the conveying roller  24  are also disposed to be spaced apart from each other in the first direction and to be in parallel to each other. The conveying roller  24  are rotatable upon contact with a printing sheet. The printing sheet is conveyed toward a position between the photosensitive drum  22  and transfer roller  23  while being in contact with the conveying roller  24  and a plurality of ribs  116  of the developing cartridge  1 . 
     In this way, the drum cartridge  2  of the present embodiment includes the conveying roller  24 . Hence, replacement of the conveying roller  24  can be realized concurrently with replacement of the drum cartridge  2 . 
     The gear portion  25  is positioned at the first drum side plate  41 . The gear portion  25  includes: a plurality of gears including the drum gear  251  described above; and a coupling  252 . The plurality of gears is accommodated in a space formed between the frame main body  31  and the frame cover  32 . The coupling  252  is exposed outside through the frame cover  32 . In a state where the process cartridge  100  is mounted in the image-forming apparatus, a drive shaft of the image-forming apparatus is connected to the coupling  252 . Rotation of the drive shaft is configured to be transmitted to the plurality of gears through the coupling  252 . 
     Incidentally, the plurality of gears included in the gear portion  25  may be configured to transmit rotational force by meshing engagement with one another, or friction against one another. 
     The charging device  26  is positioned at the one end portion  211  of the drum frame  21  in the first direction. The charging device  26  is disposed along the photosensitive drum  22 . The charging device  26  is configured to uniformly charge the peripheral surface of the photosensitive drum  22 . In the present embodiment, a Scorotron charger is employed as the charging device  26 . Employing a non-contact charger, such as a Scorotron charger, can charge the peripheral surface of the photosensitive drum  22  without any pressure thereto. Hence, the photosensitive drum  22  can be suppressed from getting distorted or damaged. Incidentally, a contact-type charger, such as a charging roller, may be employed, instead of the non-contact charger. 
     The drum cartridge  2  also includes a charging electrode  261 . The charging electrode  261  is an electrode for supplying power to the charging device  26 . The charging electrode  261  is positioned at an outer surface of the second drum side plate  42 . The charging electrode  261  is electrically in contact with the charging electrode  261 . The charging electrode  261  has a charging contact surface  262 . Upon attachment of the process cartridge  100  to the image-forming apparatus, the charging contact surface  262  is made in contact with an electrode provided in the image-forming apparatus. Power is therefore supplied to the charging device  26  from the image-forming apparatus. 
     The drum cartridge  2  of the present embodiment includes the charging device  26 , as described above. Hence, at the time of replacement of the drum cartridge  2 , the charging device  26  can also be replaced. 
     The first pressing member  27  and second pressing member  28  are positioned at the another end portion  212  of the drum frame  21  in the first direction. The first pressing member  27  protrudes toward the photosensitive drum  22  in the first direction from one end of the second connecting plate  44  in the second direction. The second pressing member  28  protrudes toward the photosensitive drum  22  in the first direction from another end of the second connecting plate  44  in the second direction. The first pressing member  27  and second pressing member  28  may be integral with the second connecting plate  44 , or may be separate members from the second connecting plate  44 . 
     Upon attachment of the developing cartridge  1  to the drum frame  21 , the casing  11  of the developing cartridge  1  is in contact with the first pressing member  27  and second pressing member  28 . With this structure, the developing cartridge  1  is pressed toward the one end portion  211  of the drum frame  21  in the first direction, thereby pressing the developing roller  13  toward the photosensitive drum  22 . 
     2-2. IC Chip 
     The drum cartridge  2  further includes an IC chip  29 . The IC chip  29  is a plate-shaped storage medium (first storage medium). The IC chip  29  stores various information relating to the drum cartridge  2  (for example, information regarding service life of components such as the photosensitive drum  22  and the charging device  26 ). 
       FIG. 5  is an external view of the IC chip  29 . As illustrated in  FIG. 5 , the IC chip  29  includes a plurality of electrical contact surfaces  291  (first electrical contact surfaces). The plurality of electrical contact surfaces  291  is arranged in line in the second direction or in the third direction. Incidentally, the IC chip  29  may have only one electrical contact surface  291 . The electrical contact surfaces  291  are made of metal which is an electrical conductor. Upon attachment of the process cartridge  100  to the image-forming apparatus, the electrical contact surfaces  291  are made in contact with electrical terminals provided in the image-forming apparatus, thereby establishing electrical connection between the electrical terminals and the electrical contact surfaces  291 . As a result, the image-forming apparatus can perform at least one of: reading out information from the IC chip  29 ; and writing information into the IC chip  29 . 
     In the state where the developing cartridge  1  is attached to the drum frame  21 , the IC chip  29  is positioned at an exposed outer surface of the drum frame  21 . Specifically, the IC chip  29  is fixed to the exposed outer surface of the drum frame  21 . This structure enables the electrical contact surfaces  291  of the IC chip  29  to contact the electrical terminals of the image-forming apparatus even in the state where the developing cartridge  1  is attached to the drum frame  21 . Incidentally, the IC chip  29  may be fixed to the drum frame  21  by bonding or screwing, for example. 
     More specifically, the electrical contact surfaces  291  are configured of: an SIO (data) terminal  291 A, a GND (ground) terminal  291 B, an SCK (serial clock) terminal  291 C, and a PWR (power) terminal  291 D. The electrical contact surfaces  291  are arranged in line, in the second direction or in third direction, sequentially in an order of: the SIO terminal  291 A, the GND terminal  291 B, the SCK terminal  291 C, and the PWR terminal  291 D. 
     Incidentally, the order of arrangement among the SIO terminal  291 A, GND terminal  291 B, SCK terminal  291 C and PWR terminal  291 D may not be limited to that of the embodiment described above. 
     For example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SIO terminal  291 A, GND terminal  291 B, PWR terminal  291 D, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SIO terminal  291 A, SCK terminal  291 C, GND terminal  291 B and PWR terminal  291 D. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SIO terminal  291 A, SCK terminal  291 C, PWR terminal  291 D, and GND terminal  291 B. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SIO terminal  291 A, PWR terminal  291 D, GND terminal  291 B, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SIO terminal  291 A, PWR terminal  291 D, SCK terminal  291 C, and GND terminal  291 B. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, SIO terminal  291 A, SCK terminal  291 C and PWR terminal  291 D. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, SIO terminal  291 A, PWR terminal  291 D, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, SCK terminal  291 C, SIO terminal  291 A, and PWR terminal  291 D. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, SCK terminal  291 C, PWR terminal  291 D, and SIO terminal  291 A. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, PWR terminal  291 D. SIO terminal  291 A, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the GND terminal  291 B, PWR terminal  291 D, SCK terminal  291 C, and SIO terminal  291 A. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, SIO terminal  291 A, GND terminal  291 B, and PWR terminal  291 D. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, SIO terminal  291 A, PWR terminal  291 D, and GND terminal  291 B. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, GND terminal  291 B, SIO terminal  291 A, and PWR terminal  291 D. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, GND terminal  291 B, PWR terminal  291 D, and SIO terminal  291 A. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, PWR terminal  291 D, SIO terminal  291 A, and GND terminal  291 B. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the SCK terminal  291 C, PWR terminal  291 D, GND terminal  291 B, and SIO terminal  291 A. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, SIO terminal  291 A, GND terminal  291 B, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, SIO terminal  291 A, SCK terminal  291 C, and GND terminal  291 B. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, GND terminal  291 B, SIO terminal  291 A, and SCK terminal  291 C. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, GND terminal  291 B, SCK terminal  291 C, and SIO terminal  291 A. 
     Alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, SCK terminal  291 C, SIO terminal  291 A, and GND terminal  291 B. 
     Still alternatively, for example, the electrical contact surfaces  291  may be arranged, in the second direction or in third direction, in an order of: the PWR terminal  291 D, SCK terminal  291 C, GND terminal  291 B, and SIO terminal  291 A. 
     Hereinafter, locations at which the IC chip  29  is possibly disposed on the outer surface of the drum frame  21  will be described. 
     (a) Possible Locations on the Drum Bottom Plate 
       FIG. 6  is a plan view of the process cartridge  100  when viewed from the side of the drum bottom plate  45 . In  FIG. 6 , locations  29 (A)- 29 (F) are indicated by broken lines as possible positions for arranging the IC chip  29 . Further, in  FIG. 6 , two-dot chain lines indicate a conveying path  9  along which printing sheets are to be conveyed. 
     The IC chip  29  is possibly disposed at the locations  29 (A)- 29 (F) on the outer surface of the drum bottom plate  45 . With such arrangements, the electrical contact surface  181  (described later) of the IC chip  18  of the developing cartridge  1  faces in the same direction as the electrical contact surfaces  291  of the IC chip  29  of the drum cartridge  2  faces. Accordingly, both the electrical contact surface  181  and electrical contact surfaces  291  can be moved in the same direction, in the same posture, at the time of insertion of the process cartridge  100  into the image-forming apparatus. Such arrangements thus facilitate establishing compatibility between reliably contact of the electrical contact surface  181  with the electrical terminal of the image-forming apparatus and reliably contact of the electrical contact surfaces  291  with other electrical terminals of the image-forming apparatus. 
     Further, a direction of force which the electrical contact surface  181  receives from the corresponding electrical terminal of the image-forming apparatus can be coincident with a direction of force which the electrical contact surfaces  291  receive from the corresponding electrical terminals of the image-forming apparatus. Hence, positioning of the process cartridge  100  relative to the image-forming apparatus can be easily realized. 
     In case of the locations  29 (A)- 29 (C),  29 (E) and  29 (F), the electrical contact surfaces  291  are positioned outward relative to the conveyor opening  451  with respect to the second direction. Specifically, in case of the locations  29 (A)- 29 (C), with respect to the second direction, the electrical contact surfaces  291  are positioned between the conveyor opening  451  and another end in the second direction of the drum frame  21 . In case of the locations  29 (E) and  29 (F), with respect to the second direction, the electrical contact surfaces  291  are positioned between the conveyor opening  451  and one end in the second direction of the drum frame  21 . That is, on the outer surface of the drum bottom plate  45 , the electrical contact surfaces  291  are positioned to be offset from the conveying path  9  for the printing sheet. This arrangement can prevent printing sheets from making contact with the electrical contact surfaces  291  while the printing sheets are being conveyed. 
     In particular, in case of the location  29 (B), the electrical contact surfaces  291  are positioned opposite the first opening  452  with respect to the conveyor opening  451 . That is, in the state where the developing cartridge  1  (described later) is attached to the drum frame  21 , at least part of the electrical contact surfaces  291  is positioned opposite the electrical contact surface  181  exposed through the first opening  452  with respect to the conveyor opening  451 . This structure enables the electrical contact surfaces ( 291  and  181 ) to contact the corresponding electrical terminals of the image-forming apparatus on both sides of the conveyor opening  451  in the second direction. The electrical contact surface  181  and electrical contact surfaces  291  are therefore suppressed from getting inclined relative to the image-forming apparatus. 
     In case of the location  29 (D), the electrical contact surfaces  291  is positioned between the conveyor opening  451  and the one end portion  211  of the drum frame  21  in the first direction. In this case as well, the electrical contact surfaces  291  can be positioned to be offset from the conveying path  9 . Accordingly, the conveyed printing sheets can be prevented from getting in contact with the electrical contact surfaces  291 . Further, the user holds the handle  441  provided at the another end portion  212  in the first direction of the drum frame  21 . Arranging the electrical contact surfaces  291  on the location  29 (D) can thus restrain the user from contacting with the electrical contact surfaces  291 . 
     In case of the location  29 (D), at least part of the electrical contact surfaces  291  may be positioned opposite the photosensitive drum  22  with respect to the transfer roller  23 . Alternatively, in case of the location  29 (D), the electrical contact surfaces  291  and photosensitive drum  22  may overlap with each other with respect to the third direction. Further, in case of the location  29 (D), it is preferable that the electrical contact surfaces  291  be positioned at a center of the drum bottom plate  45  with respect to the second direction. Specifically, at least one of the electrical contact surfaces  291  of the IC chip  29  be preferably positioned to overlap, with respect to the first direction, with a center in the second direction of the conveyor opening  451 . Incidentally, the electrical contact surfaces  291  may be positioned to be offset from the center of the conveyor opening  451  in the second direction. 
     The drum bottom plate  45  has a first end portion  455  and a second end portion  456 . The first end portion  455  is positioned at the one end of the drum frame  21  in the second direction. The second end portion  456  is positioned at the another end of the drum frame  21  in the second direction. That is, the first end portion  455  is positioned closer to the drum gear  251  than the second end portion  456  is to the drum gear  251 . The first end portion  455  and second end portion  456  are spaced apart from each other in the second direction. The electrical contact surfaces  291  may be positioned on an outer surface of the first end portion  455 , such as at the locations  29 (A),  29 (B) and  29 (C). Alternatively, the electrical contact surfaces  291  may be positioned on an outer surface of the second end portion  456 , such as at the locations  29 (E) and  29 (F). In case of the locations  29 (E) and  29 (F), vibrations originating from the drum gear  251  can be suppressed from being transmitted to the electrical contact surfaces  291 . 
     (b) Possible Locations on a Side Opposite the Drum Bottom Plate 
       FIG. 7  is a plan view of the process cartridge  100  when viewed from a side opposite the drum bottom plate  45 . In  FIG. 7 , locations  29 (G)- 29 (J) are indicated by broken lines as possible positions for arranging the IC chip  29 . 
     The electrical contact surfaces  291  may be positioned on an end face of the first drum side plate  41 , the second drum side plate  42 , the first connecting plate  43 , or the second connecting plate  44 , the end face opposite the drum bottom plate  45  with respect to the third direction. 
     Like the locations  29 (G) and  29 (I), the electrical contact surfaces  291  may be positioned on an outer surface of the one end portion  211  in the first direction of the drum frame  21 . Since the user holds the handle  441  provided at the another end portion  212  of the drum frame  21 , arranging the electrical contact surfaces  291  on the outer surface of the one end portion  211  of the drum frame  21  can reduce a likelihood that the user touches the electrical contact surfaces  291 . 
     Alternatively, the electrical contact surfaces  291  may be positioned on an outer surface of the another end portion  212  in the first direction of the drum frame  21 , just like the locations  29 (H) and  29 (J). This structure can restrict contact of the electrical contact surfaces  291  with part of the image-forming apparatus during attachment of the process cartridge  100  to the image-forming apparatus. 
     (c) Possible Locations on the First Connecting Plate 
       FIG. 8  is a plan view of the process cartridge  100  when viewed from a side of the first connecting plate  43  (one side in the first direction). In  FIG. 8 , locations  29 (K) and  29 (L) are indicated by broken lines as possible positions for arranging the IC chip  29 . 
     The electrical contact surfaces  291  may be disposed on an outer surface of the first connecting plate  43 , just like the locations  29 (K) and  29 (L). That is, the electrical contact surfaces  291  may be positioned on the outer surface of the one end portion  211  in the first direction of the drum frame  21 . Since the user holds the handle  441  provided at the another end portion  212  of the drum frame  21 , arranging the electrical contact surfaces  291  on the outer surface of the one end portion  211  of the drum frame  21  can reduce a likelihood that the user touches the electrical contact surfaces  291 . 
     In case of the locations  29 (K) and  29 (L), the electrical contact surfaces  291  and the handle  441  to be held by the user are positioned at opposite ends of the drum cartridge  2  with respect to the first direction. Further, a distance in the first direction between the first connecting plate  43  and photosensitive drum  22  is shorter than a distance in the first direction between the first connecting plate  43  and the handle  441 . Arranging the electrical contact surfaces  291  away from the handle  441  in this way can help restricting the user from touching the electrical contact surfaces  291 . 
     The first connecting plate  43  has a first end portion  431  and a second end portion  432 . The first end portion  431  is positioned at the one end of the drum frame  21  in the second direction. The second end portion  432  is positioned at the another end of the drum frame  21  in the second direction. That is, the first end portion  431  is positioned closer to the drum gear  251  than the second end portion  432  is to the drum gear  251 . Part of an outer surface of the drum gear  251  is covered with the first end portion  431 . The first end portion  431  and second end portion  432  are spaced apart from each other in the second direction. The electrical contact surfaces  291  may be positioned on an outer surface of the first end portion  431 , like the location  29 (K). Alternatively, the electrical contact surfaces  291  may be positioned at an outer surface of the second end portion  432 , like the location  29 (L). In case of the location  29 (L), vibrations originating from the drum gear  251  is less likely to be transmitted to the electrical contact surfaces  291 . 
     (d) Possible Locations on the Second Connecting Plate 
       FIG. 9  is a plan view of the process cartridge  100  when viewed from a side of the second connecting plate  44  (another side in the first direction). In  FIG. 9 , locations  29 (M)- 29 (Q) are indicated by broken lines as possible positions for arranging the IC chip  29 . 
     The electrical contact surfaces  291  may be disposed on an outer surface of the second connecting plate  44 , just as the locations  29 (M)- 29 (Q). That is, the electrical contact surfaces  291  may be positioned on the outer surface of the another end portion  212  in the first direction of the drum frame  21 . This structure can restrict contact of the electrical contact surfaces  291  against part of the image-forming apparatus during attachment of the process cartridge  100  to the image-forming apparatus. 
     In particular, in case of the locations  29 (M),  29 (N),  29 (P) and  29 (Q), the electrical contact surfaces  291  are positioned to be spaced apart from the handle  441  in the second direction. That is, the electrical contact surfaces  291  are arranged at different positions from the handle  441  with respect to the second direction. This arrangement can therefore suppress the user from touching the electrical contact surfaces  291 . 
     The second connecting plate  44  has a first end portion  442  and a second end portion  443 . The first end portion  442  is positioned at the one end of the drum frame  21  in the second direction. The second end portion  443  is positioned at the another end pf the drum frame  21  in the second direction. In other words, the first end portion  442  is positioned closer to the drum gear  251  than the second end portion  443  is to the drum gear  251 . The first end portion  442  and the second end portion  443  are spaced apart from each other in the second direction. The electrical contact surfaces  291  may be positioned at an outer surface of the first end portion  442 , just like the location  29 (M). Alternatively, the electrical contact surfaces  291  may be positioned an outer surface of the second end portion  443 , like the location  29 (Q). In case of the location  29 (Q), vibrations originating from the drum gear  251  is less likely to be transmitted to the electrical contact surfaces  291 . 
     (e) Possible Locations on the First Drum Side Plate 
       FIG. 10  is a plan view of the process cartridge  100  when viewed from a side of the first drum side plate  41  (one side in the second direction). In  FIG. 10 , locations  29 (R) and  29 (S) are indicated by broken lines as possible positions for arranging the IC chip  29 . 
     The electrical contact surfaces  291  may be positioned on an outer surface of the first drum side plate  41 , like the locations  29 (R) and  29 (S). With such arrangements, the electrical contact surfaces  291  and the charging contact surface  262  are positioned opposite each other with respect to the second direction. Hence, the electrical contact surfaces  291  are pressed toward the corresponding electrical terminals of the image-forming apparatus by force applied to the charging contact surface  262  as a result of contact thereof with the corresponding electrical terminal upon attachment of the process cartridge  100  to the image-forming apparatus. This structure allows the electrical contact surfaces  291  to stably contact the corresponding electrical terminals of the image-forming apparatus. 
     (f) Possible Locations on the Second Drum Side Plate 
       FIG. 11  is a plan view of the process cartridge  100  when viewed from a side of the second drum side plate  42  (another side in the second direction). In  FIG. 11 , locations  29 (T)- 29 (V) are indicated by broken lines as possible positions for arranging the IC chip  29 . 
     The electrical contact surfaces  291  may be positioned on an outer surface of the second drum side plate  42 , like the locations  29 (T)- 29 (V). With such arrangements, the electrical contact surfaces  291  and the charging contact surface  262  are positioned at the same side as each other with respect to the second direction. The electrical contact surfaces  291  and charging contact surface  262  can be moved in the same direction, in the same posture, during insertion of the process cartridge  100  into the image-forming apparatus. This structure can easily achieve a balance between reliably contact of the electrical contact surfaces  291  with the electrical terminals of the image-forming apparatus and reliably contact of the charging contact surface  262  with the corresponding electrical terminal of the image-forming apparatus. 
     Further, a direction of force which the electrical contact surfaces  291  receives from the electrical terminals of the image-forming apparatus can be coincident with a direction of force that the charging contact surface  262  receives from the corresponding electrical terminal of the image-forming apparatus. Accordingly, positioning of the process cartridge  100  relative to the image-forming apparatus can be easily obtained. 
     Further, in case of the location  29 (U), at least part of the electrical contact surfaces  291  is positioned between the charging contact surface  262  and the drum shaft  222 . In case of the location  29 (T), at least part of the electrical contact surfaces  291  is positioned opposite the charging contact surface  262  with respect to the drum shaft  222 . 
     3. Developing Cartridge 
       FIGS. 12 and 13  are perspective views of the developing cartridge  1 . Hereinafter, the developing cartridge  1  in its attached state to the drum cartridge  2  will be described using the above-described first direction, second direction and third direction. The developing cartridge  1  is configured to supply toner, a developing agent, to the photosensitive drum  22  of the drum cartridge  2 . As illustrated in  FIGS. 12 and 13 , the developing cartridge  1  of the present embodiment includes the casing  11 , an agitator  12 , the developing roller  13 , a supply roller  14 , a gear portion  15 , a developing electrode  16 , a supply electrode  17 , and the IC chip  18 . 
     The casing  11  is a casing for accommodating toner therein. The casing  11  includes the first developing side plate  111  and the second developing side plate  112 . The first developing side plate  111  is positioned at one end of the casing  11  in the second direction. The second developing side plate  112  is positioned at another end of the casing  11  in the second direction. The first developing side plate  111  and second developing side plate  112  are spaced apart from each other in the second direction. The gear portion  15  is positioned at an outer surface of the first developing side plate  111 . The developing electrode  16  and supply electrode  17  are positioned at an outer surface of the second developing side plate  112 . An accommodation chamber  113  is provided inside the casing  11 . Toner is accommodated within the accommodation chamber  113 . The casing  11  also has an open section  114 . The open section  114  is positioned at one end portion of the casing  11  in the first direction. The accommodation chamber  113  is in communication with the outside through the open section  114 . 
     The casing  11  further includes a handle  115 . Of one end portion and another end portion of the casing  11  in the first direction, the handle  115  is positioned at the another end portion of the casing  11 , the another end portion being farther away from the developing roller  13  than the one end portion is from the developing roller  13 . The user of the image-forming apparatus holds the handle  115  when attaching and detaching the developing cartridge  1  relative to the drum cartridge  2 . Further, the casing  11  includes the plurality of ribs  116 . Of outer surfaces of both end portions of the casing  11  in the third direction, the plurality of ribs  116  is positioned on the outer surface that is farther away from the developing roller  13  than the other outer surface is from the developing roller  13 . The plurality of ribs  116  is arranged in line in the second direction at intervals. Each rib  116  protrudes outward in the third direction from the outer surface of the casing  11 . 
     The agitator  12  includes an agitator shaft  121  and an agitating blade  122 . The agitator shaft  121  is rotatable about a rotational axis extending in the second direction. The agitating blade  122  extends radially outward from the agitator shaft  121 . At least part of the agitator shaft  121  and the agitating blade  122  are positioned within the accommodation chamber  113 . An agitator gear, which is included in the gear portion  15 , is fixed to one end of the agitator shaft  121  in the second direction. The agitator shaft  121  and agitating blade  122  are thus rotatable by driving force from the gear portion  15 . In accordance with rotation of the agitating blade  122 , the toner within the accommodation chamber  113  is agitated. 
     The developing roller  13  is a roller rotatable about a rotational axis (second axis) extending in the second direction. The developing roller  13  is positioned at the open section  114  of the casing  11 . That is, the developing roller  13  is positioned at the one end portion of the casing  11  in the first direction. Upon attachment of the developing cartridge  1  to the drum cartridge  2 , an outer peripheral surface of the developing roller  13  is in contact with the outer peripheral surface of the photosensitive drum  22 . 
     The developing roller  13  includes a developing-roller body  131  and the developing-roller shaft  132 . The developing-roller body  131  is a cylindrical-shaped member extending in the second direction. As a material for the developing-roller body  131 , rubber having elasticity may be used, for example. The developing-roller shaft  132  is a columnar-shaped member penetrating the developing-roller body  131  in the second direction. As a material for the developing-roller shaft  132 , metal or an electrically conductive resin is available, for example. The developing-roller body  131  is fixed to the developing-roller shaft  132  so as not to rotate relative to the developing-roller shaft  132 . 
     A developing-roller gear, which is included in the gear portion  15 , is fixed to the one end of the developing-roller shaft  132  in the second direction. With this structure, the developing-roller shaft  132  and developing-roller body  131  are rotatable by driving force from the gear portion  15 . Incidentally, the developing-roller shaft  132  may not penetrate the developing-roller body  131  in the second direction. For example, a pair of developing-roller shafts  132  may be provided each at each end in the second direction of the developing-roller body  131  to extend outward therefrom in the second direction. 
     The supply roller  14  is positioned between the developing roller  13  and the accommodation chamber  113 . The supply roller  14  is a roller rotatable about a rotational axis (supply roller axis) extending in the second direction. The supply roller  14  includes a supply-roller body  141  and a supply-roller shaft  142 . The supply-roller body  141  is a cylindrical-shaped member extending in the second direction. The supply-roller body  141  has an outer peripheral surface in contact with the outer peripheral surface of the developing-roller body  131 . As a material for the supply-roller body  141 , a rubber with elasticity may be used, for example. The supply-roller shaft  142  is a columnar-shaped member penetrating the supply-roller body  141  in the second direction. As a material for the supply-roller shaft  142 , metal or an electrically conductive resin may be used, for example. The supply-roller body  141  is fixed to the supply-roller shaft  142  so as not to rotate relative to the supply-roller shaft  142 . 
     A supply-roller gear, which is included in the gear portion  15 , is fixed to one end of the supply-roller shaft  142  in the second direction. With this structure, the supply-roller shaft  142  and supply-roller body  141  are rotatable by driving force of the gear portion  15 . Incidentally, the supply-roller shaft  142  may not penetrate the supply-roller body  141  in the second direction. For example, a pair of supply-roller shafts  142  may be provided each at each end in the second direction of the supply-roller body  141  to extend outward therefrom in the second direction. 
     When the gear portion  15  is driven, toner is supplied to the outer peripheral surface of the developing roller  13  from the accommodation chamber  113  through the supply roller  14 . At this time, the toner is tribo-charged between the supply roller  14  and the developing roller  13 . On the other hand, a bias voltage is applied to the developing-roller shaft  132  of the developing roller  13 . Accordingly, the toner is attracted to the outer peripheral surface of the developing-roller body  131  by static electricity between the developing-roller shaft  132  and the toner. 
     The developing cartridge  1  further includes a layer-thickness regulating blade not illustrated in the drawings. The layer-thickness regulating blade is configured to regulate the toner supplied over the outer peripheral surface of the developing-roller body  131  into a uniform thickness. Thereafter, the toner on the outer peripheral surface of the developing-roller body  131  is supplied to the photosensitive drum  22 . At this time, the toner is moved from the developing-roller body  131  to the photosensitive drum  22  according to electrostatic latent images formed on the outer peripheral surface of the photosensitive drum  22 . The electrostatic latent images are thus developed into visible images on the outer peripheral surface of the photosensitive drum  22 . 
     The gear portion  15  is positioned at the outer surface of the first developing side plate  111  of the casing  11 . The gear portion  15  includes: a plurality of gears including the above-described agitator gear, developing-roller gear, and supply-roller gear; a coupling  151 ; and the gear cover  152 . The gear cover  152  is fixed to the first developing side plate  111  of the casing  11 , for example, by screwing. At least part of the plurality of gears are positioned between the first developing side plate  111  and the gear cover  152 . The coupling  151  is exposed through the gear cover  152 . Upon attachment of the process cartridge  100  to the image-forming apparatus, a drive shaft of the image-forming apparatus is connected to the coupling  151 . Rotation of the drive shaft is configured to be transmitted, via the coupling  151 , to the plurality of gears including the agitator gear, the developing-roller gear, and the supply-roller gear. 
     Incidentally, the plurality of gears included in the gear portion  15  may be configured to transmit rotational force by meshing engagement between gear teeth, or by friction between each other. 
     The developing electrode  16  is an electrode for supplying power to the developing roller  13 . The developing electrode  16  is positioned at the outer surface of the second developing side plate  112  of the casing  11 . Metal or electrically conductive resin may be employed as the developing electrode  16 . The developing electrode  16  rotatably supports the another end of the developing-roller shaft  132  in the second direction, while being electrically in contact with the another end of the developing-roller shaft  132  in the second direction. The developing electrode  16  has a developing contact surface  161 . Upon attachment of the process cartridge  100  to the image-forming apparatus, the developing contact surface  161  makes contact with a corresponding electrical terminal provided in the image-forming apparatus, thereby supplying power to the developing-roller shaft  132  from the image-forming apparatus. 
     The supply electrode  17  is an electrode for supplying power to the supply roller  14 . The supply electrode  17  is positioned at the outer surface of the second developing side plate  112  of the casing  11 . Metal or electrically conductive resin may be employed as the supply electrode  17 . The supply electrode  17  rotatably supports another end of the supply-roller shaft  142  in the second direction, while being electrically in contact with the another end of the supply-roller shaft  142  in the second direction. The supply electrode  17  has a supply contact surface  171 . Upon attachment of the process cartridge  100  to the image-forming apparatus, the supply contact surface  171  makes contact with a corresponding electrical terminal provided in the image-forming apparatus. A bias voltage is thus suppled to the supply-roller shaft  142  from the image-forming apparatus. As a result, a bias voltage is generated between the developing roller  13  and the supply roller  14 . 
     The IC chip  18  is a plate-shaped storage medium (second storage medium). The IC chip  18  stores various information relating to the developing cartridge  1  (for example, information regarding service life of components such as the developing roller  13 ). As illustrated in  FIG. 13 , the IC chip  18  is positioned at one end portion of the casing  11  in the second direction. In the present embodiment, of outer surfaces of both end portions of the gear cover  152  in the third direction, the IC chip  18  is fixed to the outer surface that is positioned farther away from the developing roller  13  than the other outer surface is from the developing roller  13 . Incidentally, of outer surfaces of both end portions of the casing  11  in the third direction, the IC chip  18  may be fixed to the outer surface that is positioned farther away from the developing roller  13  than the other outer surface is from the developing roller  13 . 
     The IC chip  18  includes a plurality of the electrical contact surfaces  181  (second electrical contact surface). The electrical contact surfaces  181  are arranged in line with respect to the second direction. Each electrical contact surface  181  is a surface orthogonal to the third direction. Incidentally, the IC chip  18  may have one electrical contact surface  181 . The electrical contact surfaces  181  are made of metal which is an electrical conductor. Upon attachment of the process cartridge  100  to the image-forming apparatus, the electrical contact surfaces  181  make contact with corresponding electrical terminals provided in the image-forming apparatus. The electrical contact surfaces  181  and the electrical terminals are thus electrically connected to each other. As a result, the image-forming apparatus can perform at least one of: reading out information from the IC chip  18 ; and writing information into the IC chip  18 . 
     4. Modifications 
     While the present disclosure has been described with reference to one embodiment thereof, the present disclosure should not be limited to the depicted embodiment. 
     For example, in the above-described embodiment, an IC chip having electrical contact surfaces is fixed to an outer surface of a drum frame. However, only electrical contact surfaces may be fixed to an outer surface of a drum frame, while a remaining portion other than the electrical contact surfaces may be disposed at a different portion of a drum cartridge. 
     Further, the first direction and the second direction may not be orthogonal to each other. The second direction and the third direction may not be orthogonal to each other. The first direction and the third direction may not be orthogonal to each other. 
     Detailed shapes of a developing cartridge and a drum cartridge may be different from those illustrated in each drawing of the present application. Further, elements appeared in the above-described embodiment and modifications may be combined with one another, appropriately, as long as no contradiction is generated.