Abstract:
An imaging cartridge includes an image carrier, a developing device, a cleaning device, a waste toner box, a communication section and transporter means. A communication section formed by positioning a first joint section of the cleaning device and a second joint section of the waste toner box in overlapping positions. Opposed faces of the first joint section and the second joint section are formed such that the first extended regions are gradually extended toward the image carrier and the second extended regions are gradually extended toward the opposed side of the image carrier.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an imaging cartridge and an image forming apparatus. 
     Conventionally, as image forming apparatuses equipped with imaging cartridges, the apparatuses structured so that component members having similar lifetime are packed into a process cartridge are known (see, e.g., JP 2006-267922 A, JP 2005-140898 A). 
     However, in the conventional structure, downsizing of the imaging cartridge has not been taken into consideration. Accordingly, image forming apparatuses which are loaded with a number of imaging cartridges have a problem that the entire apparatus grows in size. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an imaging cartridge and an image forming apparatus which can be downsized even with simple structure. 
     As a means to accomplish the above object, there is provided, in the present invention, an imaging cartridge which can be loaded into and unloaded from an image forming apparatus body, including an image carrier, a developing device for developing an electrostatic latent image on the image carrier to form a toner image, a cleaning device for collecting toner which remains on the image carrier even after transfer of the toner image, a new toner box for storing toner fed to the developing device, and a waste toner box for storing the toner collected by the cleaning device, in which the image carrier, the developing device and the cleaning device are juxtaposed with the new toner box and the waste toner box, the cleaning device and the waste toner box are placed adjacent to each other, a first joint section of the cleaning device and a second joint section of the waste toner box are positioned so as to overlap each other in a direction perpendicular to an adjoining direction and are communicated through a communication section, opposed faces of the first joint section and the second joint section are formed in a state of being inclined with respect to the adjoining direction, and transportation means for transporting waste toner is housed in respective extended regions formed by inclining the opposed faces. 
     This structure makes it possible to secure the space which can house the transportation means without increasing the occupancy space in the overlapping direction of each joint section. 
     It is preferable that the transportation means is constituted of a conveying screw which is made of a spiral screw formed around a shank and which serves to transport waste toner from one end side of the shank toward the other end side, and the communication section is formed downstream in a transportation direction of the waste toner by the conveying screw. 
     This structure makes it possible to keep an opening area in the communication section small and to secure desired sealing property in the communication section easily at low costs. 
     It is preferable that a drum unit including the image carrier and the cleaning device is formed, a process unit including the new toner box, the waste toner box and the developing device is used, and the drum unit and the process unit are placed adjacent to each other and are detachably loaded. 
     This structure makes it possible to pack the components having similar lifetime into one unit. Since the new toner box and the waste toner box are integrated with each other, they can be handled conveniently. 
     It is preferable that a process unit including the image carrier, the developing device and the cleaning device is formed, a toner box unit including the new toner box and the waste toner box is formed, and the toner box unit and the process unit are placed adjacent to each other and are detachably loaded. 
     Since this structure makes it possible to load and unload only those members which serve to store toner as separate units, toner can be replaced easily. 
     It is preferable that the new toner box and the developing device are placed adjacent to each other and are also placed to overlap the cleaning device and the waste toner box, a third joint section of the new toner box and a fourth joint section of the developing device are positioned so as to overlap each other in a direction perpendicular to an adjoining direction, opposed faces of the third joint section and the fourth joint section are formed in parallel with opposed faces of the first joint section and the second joint section, and transportation means for transporting waste toner is housed in respective internal extended regions formed by inclining the opposed faces. 
     With this structure, it becomes possible to keep the occupancy space in the overlapping direction small not only in the joint section between the waste toner box and the cleaning device but also in the joint section between the new toner box and the developing device. 
     Also as a means to accomplish the above object in the present invention, an image forming apparatus includes any one of the imaging cartridges described above. 
     It is preferable that the image forming apparatus body, which the imaging cartridge can be loaded into and unloaded from, includes a cartridge receiving section having a mounting surface which is inclined with respect to a floor, and the communication section of the imaging cartridge is formed so as to extend in a perpendicular direction in a state of being attached to the cartridge receiving section. 
     With this structure, it becomes possible to move the toner with ease through a coupled section. That is, in the coupled section formed along with the perpendicular direction, the toner can smoothly be moved by its own weight almost without receiving frictional resistance. Therefore, problems such as clogging will not arise. 
     According to the present invention, the first joint section of the cleaning device and the second joint section of the waste toner box are structured to be connected to each other at their inclined opposed faces through the communication section, so that the extended region capable of housing the transportation means can be secured, making it possible to suppress increases in the occupancy space in the overlapping direction. In other words, it becomes possible to achieve downsizing of the imaging cartridge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross sectional view showing an image forming apparatus having an imaging cartridge in a first embodiment of the present invention; 
         FIG. 2  is a schematic cross sectional view showing the image forming apparatus of  FIG. 1  with a door opened; 
         FIG. 3  is a schematic cross sectional view showing the imaging cartridge of  FIG. 1 ; 
         FIG. 4  is a schematic cross sectional view showing the imaging cartridge of  FIG. 3  in the state of being attached to a cartridge receiving section of the apparatus body; 
         FIG. 5  is a schematic cross sectional view showing a coupled section and the vicinity thereof in assembling the imaging cartridge of  FIG. 3 ; 
         FIG. 6  is a schematic cross sectional view showing the imaging cartridge of  FIG. 3  in comparison with an imaging cartridge different in structure; 
         FIG. 7  is a schematic cross sectional view showing an imaging cartridge in a second embodiment of the present invention; 
         FIG. 8  is a schematic cross sectional view showing the imaging cartridge of  FIG. 7  in the state of being attached to a cartridge receiving section of the apparatus body; and 
         FIG. 9  is a schematic cross sectional view showing an imaging cartridge in a third embodiment of the present invention. 
     
    
    
     DESCRIPTION OF REFERENCE NUMERAL 
     
         
           1 . Apparatus body 
           1   a . Door 
           2 . Transfer belt 
           3 . Cartridge receiving section 
           4 . Imaging cartridge 
           5 . Laser exposure device 
           6 . Electric power unit 
           7 . Control device 
           8 . Fixing device 
           9 . Paper ejecting roller 
           10 . Paper ejection tray 
           11 . Paper ejection device 
           12 . Paper cassette 
           13 . Feed roller 
           14 . Sheet feeding device 
           15 . Photoconductor drum (image carrier) 
           16 . Charging device 
           17 . Developing device 
           18 . Cleaning device 
           19 . New toner box 
           20 . Waste toner box 
           21 . Transfer device 
           22 . Timing roller 
           23 . Drum unit 
           24 . Process unit 
           25 . Charging roller 
           26 . Casing 
           27 . First transportation member 
           28 . Second transportation member 
           29 . Collection port 
           30 . Cleaner blade 
           31 . First joint section 
           31   a . Opposed face 
           32 . First extended region 
           33 . Delivery opening 
           34 . Communication section 
           35 . Feed roller 
           36 . Developing roller 
           37 . Second joint section 
           37   a . Opposed face 
           38 . Third transportation member 
           39 . Second extended region 
           40 . Reception opening 
           41 . Third joint section 
           42 . Fourth joint section 
           43 . Fourth transportation member 
           44 . Fifth transportation member 
           44 . Sixth transportation member 
           50 . Process unit 
           51 . Toner bottle 
           52 . Coupled section 
       
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the present invention will be described hereinbelow with reference to the drawings. 
       FIG. 1  shows an image forming apparatus (tandem-type color laser printer) having an imaging cartridge  4  according to the first embodiment of the present invention. 
     Inside an apparatus body  1  of the image forming apparatus, a transfer belt  2  stretched over a plurality of rollers is placed. Also inside the apparatus body  1 , in a cartridge receiving section  3  (see  FIG. 4 ) formed at the rear face side (left-hand side in  FIG. 1 ) of the apparatus body  1  from the transfer belt  2 , four imaging cartridges  4 Y,  4 C,  4 M and  4 K of yellow, magenta, cyan and black are detachably placed in the longitudinal direction. The cartridge receiving section  3  has a mounting surface  3   a  which is inclined with respect to the floor (level surface), i.e., inclined downward with respect to the loading direction of the imaging cartridge  4 . Further, the apparatus body  1  accommodates a laser exposure device  5 , an electric power unit  6  for supplying electric power to the entire apparatus, and a control device  7  for controlling operation of each section on the side further closer to the rear face side than the imaging cartridges  4 Y- 4 K. A fixing device  8  and a paper ejection device  11  composed of a paper ejecting roller  9  and a paper ejection tray  10  are placed on the upper side of the apparatus body  1 . A sheet feeding device  14  composed of a paper cassette  12  and a feed roller  13  is placed on the lower side in the apparatus body  1 . The paper cassette  12  can be attached to and detached from the front-face side (right-hand side in  FIG. 1 ) of the apparatus body  1 . A door  1   a  which can be rotated around an unshown pivot so as to be opened and closed is provided on the front-face side of the apparatus body  1 , and the transfer belt  2  is placed in the door  1   a . As shown in  FIG. 2 , as the door  1   a  is opened, the transfer belt  2  is put in a retreating position, where the imaging cartridges  4 Y- 4 K can be loaded onto and unloaded from the front-face side of the apparatus body  1 . 
     Each of the imaging cartridges  4 Y- 4 K are composed of, as shown in  FIG. 3 , a charging device  16 , a developing device  17  and a cleaning device  18  which are placed around a cylindrical photoconductor drum  15  (image carrier) provided in a rotatable manner, as well as a new toner box  19  for storing unused toner (new toner), and a waste toner box  20  for storing used toner (waste toner). Toner of one corresponding kind among yellow, magenta, cyan, and black is stored in the new toner box  19  in each one of the imaging cartridges  4 Y- 4 K. The transfer roller  21  is each placed so as to face the photoconductor drum  15  of each of the imaging cartridges  4 Y- 4 K across the transfer belt  2 . 
     Brief description is now given of the process in each of the imaging cartridges  4 Y- 4 K. First, the photoconductor drum  15  is charged by the charging device  16 , and then is irradiated with a laser beam from the laser exposure device  5  to form an electrostatic latent image on the photoconductor drum  15  based on an image signal. With the toner fed from the new toner box  19 , the developing device  17  develops the electrostatic latent image on the photoconductor drum  15  to form a toner image. The tone that remains on the photoconductor  21  even after transfer of the toner image to a paper sheet or a recording medium P is collected by the cleaning device  18  and stored in the waste toner box  20 . 
     The image forming apparatus is a type of the apparatus which feeds the recording medium P from the paper sheet cassette  12  to the front-face side and transports it upward while forming an image thereon, before discharging it to the rear face side. More specifically, the recording medium P sent out from the paper sheet cassette  12  to the front-face side sheet by sheet by the feed roller  13  passes through a timing roller  22  before being electrostatically held by the transfer belt  2 , and is transported upward. Whenever the recording medium P passes through between the photoconductor drum  15  in each imaging cartridges  4 Y- 4 K and the corresponding transfer rollers  21 , a toner image of one color is transferred onto the recording medium P. The recording medium P with toner images transferred thereon in superimposition one on another by the imaging cartridges  4 Y- 4 K is transported to the fixing device  8 , where toner images are fixed by heating and pressurization, and then the recording medium P is discharged by the paper ejecting roller  9  to the paper ejection tray  10 . 
     Description is now given of the imaging cartridges  4 Y- 4 K in detail. Hereinafter, when it is not necessary to distinguish four imaging cartridges  4 Y- 4 K, reference numeral “ 4 ” is used to denote the imaging cartridge  4 . 
     The imaging cartridge  4  is composed of a drum unit  23  and a process unit  24  which are provided in a detachable manner. 
     The drum unit  23  is composed of a photoconductor drum  15 , a charging device  16  and a cleaning device  18 . The charging device  16  incorporates a charging roller  25  for charging the photoconductor drum  15 . The cleaning device  18  houses a first transportation member  27  and a second transportation member  28  in a casing  26 . A collection port  29  is formed in one end side of the casing  26 , where a cleaner blade  30  is provided. The cleaner blade  30  can slide on the peripheral face of the photoconductor drum  1  as the photoconductor drum  1  rotates, and collects the waste toner which remains on the photoconductor drum  15 . The first transportation member  27  has a plurality of blades formed around its shank along its axial center. The first conveyance member  27  is placed in the vicinity of the collection port  29  with its axial center extending in the width direction of the casing  26 . As the first conveyance member  27  rotates, the waste toner collected from the collection port  29  is transported to a delivery opening  33  side of the casing  26 . The second transportation member  28  has a spiral blade (screw) around its shank. The second transportation member  28  is placed in the vicinity of the delivery opening  33  so that its axial center extends in the width direction of the casing  26 . As the second transportation member  28  rotates, the waste toner transported by the first conveyance member  27  is transported from one end side of the shank to the other end side. 
     The other end side of the casing  26  constitutes a first joint section  31 . In the first joint section  31 , the lower surface forms an opposed face  31   a  which is gradually inclined upward. Thereby, a first extended region  32  which is gradually extended toward a base section is formed in the internal space of the first joint section  31 . The first extended region  32  secures a space which can accommodate the second transportation member  28 . The opposed face  31   a  has a delivery opening  33  formed downstream in the transportation direction of the waste toner by the second transportation member  28 . As shown in  FIG. 5 , a PET film stuck on the surface of a sealing member  33   a  which is made of elastically deformable resin (e.g., urethane foam material) and which is in a rectangular frame shape is stuck on the opening edge at the delivery opening  33 . The opening formed by the sealing member  33   a  is openable and closable by a shutter  33   b . Moreover, the sealing member  33   a  constitutes a communication section  34  together with a later-described sealing member  40   a  of the waste toner box  20 . 
     The process unit  24  is composed of a new toner box  19  and a waste toner box  20 , which are coupled to each other by an unshown support member in a manner allowing elastic relative displacement. The new toner box  19  has an internal space for storing uncharged new toner. Moreover, a feed roller  35  and a developing roller  36  are incorporated in one end side of the new toner box  19 . The developing roller  36 , which is placed at the diagonally lower side of the photoconductor drum  15 , feeds toner onto the photoconductor drum  15  so as to develop an electrostatic latent image to form a toner image. The waste toner box  20  is so structured that one end side is constituted of a second joint section  37  and the other end side incorporates a third transportation member  38 . In the second joint section  37 , the upper surface forms as opposed face  37   a  which is gradually inclined upward. Thereby, a second extended region  39  which gradually extended toward a base section is formed in the internal space of the second joint section  37  as with the case of the first joint section  31 . The second extended region  39  secures a space which can accommodate the third transportation member  38 . Moreover, the opposed face  37   a  faces the opposed face of the first joint section  31  at a prescribed interval, where a reception opening  40  which faces the delivery opening  33  is formed. As shown in  FIG. 5 , a sealing member  40   a  having the same structure as the delivery opening  33  is also stuck on the opening edge of the reception opening  40 . The opening formed by the sealing member  33   a  is openable and closable by a shutter  40   b . The waste toner which has entered via the reception opening  40  is transported to the opposite side of the reception opening  40  while being diffused by rotation of the third transportation member  38 . 
     The above-structured imaging cartridge  4  is formed by assembling the drum unit  23  which is made up of the photoconductor drum  15 , the charging device  16  and the cleaning device  18 , and the process unit  24  which is made up of the new toner box  19  and the waste toner box  20 . In this case, the developing roller  36  of the new toner box  19  is positioned in the vicinity of the diagonally lower side of the photoconductor drum  15 , while the waste toner box  20  is adjacent to the lateral side of the casing  26  of the cleaning device  18 . An inclined opposed face is formed in the first joint section  31  of the casing  26 , while a similar opposed face is also formed in the second joint section  37  of the waste toner box  20 , and these opposed faces are placed so as to face each other as shown in  FIG. 5A . Then, as shown in  FIG. 5B , the sealing member  33   a  of the first joint section  31  and the sealing member  40   a  of the second joint section  37  come into pressure contact with each other, by which successful sealed condition is established. At this point, when the shutters  33   b  and  40   b  are opened, a communication section  34  for communicating the delivery opening  33  and the reception opening  40  is formed by the sealing members  33   a  and  40   a  as shown in  FIG. 5C . 
     The imaging cartridge  4  assembled in this way has the vertical size limited by the opposed faces  31   a  and  37   a  formed in the first joint section  31  and the second joint section  37  as shown in  FIG. 6A . Therefore, as shown in  FIG. 6B , it becomes possible to form the imaging cartridge  4  smaller by a prescribed size β than an imaging cartridge without such structure. 
     The imaging cartridge  4  having the above structure is used in the state of being attached to a cartridge receiving section  3  of the apparatus body  1 . A mounting surface  3   a  of the cartridge receiving section  3  is formed in the state of being inclined by a predetermined angle α with respect to the level surface. The angle of inclination α is preferably 18-45 degrees. It is to be noted that the effect of decreasing the height size can be maximized with only the imaging cartridge  4  by setting the angle of inclination a to 45 degrees. Also, loading of imaging cartridge  4  into the apparatus body  1  can be facilitated by setting the angle of inclination α to 18-30 degrees. In the state where the imaging cartridge  4  is loaded into the apparatus body  1 , the imaging cartridge  4  is also inclined so that the communication section  34  extends in the perpendicular direction. In other words, the communication section  34  enables the waste toner to smoothly move from the first joint section  31  to the second joint section  37  even if the waste toner has fluidity poorer than normal toner. It is to be noted that it becomes possible to achieve smooth free fall of the toner by setting the direction of the communication section  34  in the range of ±15 degrees from the perpendicular direction. 
     Description is now given of the operation of the image forming apparatus with the above structure. In the following section, description is mainly given of the collection method of the waste toner which characterizes the present invention, and therefore description of other aspects will be omitted. 
     The waste toner which remains on the photoconductor drum  15  without being transferred onto a recording medium P is scraped by the cleaner blade  30 , and is collected into the casing  26  of the cleaning device  18  via the collection port  29 . The waste toner collected in the casing  26  is transported by rotation of the first transportation member  27  to the first joint section  31  on the other end side. In the first joint section  31 , the transported waste toner is collected from the one end side to the other end side, i.e., to the delivery opening side, by rotation of the second transportation member  28 . 
     Since the communication section  34  extends vertically downward, the waste toner collected at the delivery opening side moves to the reception opening  40  smoothly, and flows into the second joint section  37  of the waste toner box  20 . In the second joint section  37 , the waste toner inflow is transported so as to be diffused in an axial direction (to the side opposite to the second transportation member  28 ) and to the other end side of the waste toner box  20  (to the side opposite to the second joint section  37 ) by rotation of the third transportation member  38 . Thus, it becomes possible to put the waste toner into a uniform state within the waste toner box  20  and to transport it to the other end side. 
     Second Embodiment 
       FIG. 7  shows an imaging cartridge  4  in the second embodiment of the present invention. The imaging cartridge  4  is structured so that a process unit  50  made up of a developing device  17 , a photoconductor drum  15 , a charging device  16  and a cleaning device  18  is detachably juxtaposed with a toner bottle  51  made up of a new toner box  19  and a waste toner box  20 . 
     The new toner box  19  and the developing device  17  are placed adjacent to each other, while a third joint section  41  constituting one end side of the new toner box  19  and a fourth joint section  42  constituting one end side of a casing  26  of the developing device  17  are placed so as to overlap each other in a vertical direction. 
     In the third joint section  41 , the lower surface forms an opposed face which is gradually inclined downward toward the top end. Therefore, an extended region is formed not in the base section side as seen in the first joint section but in the top end side of the third joint section  41 . A fourth transportation member  43  is placed in the extended region. The fourth transportation member  43 , like the second transportation member  28 , transports new toner from one end side toward the other end side within the third joint section  41 , and moves the toner to the fourth joint section  42  via a coupled section  52  provided on the other end side. 
     Also in the fourth joint section  42 , the upper surface forms an opposed face which is gradually inclined upward toward the top end. Also in the fourth joint section  42 , as in the third joint section  41 , an extended region is formed in the top end side, where a fifth transportation member  44  is placed. The fifth transportation member  44 , like the third transportation member  38 , transports the new toner which flowed therein via the communication section  34  in the axial direction and to the side of a sixth transportation member provided in the vicinity thereof. 
     According to the imaging cartridge  4  having the above structure, the overlapped state of the third joint section  41  and the fourth joint section  42  is almost identical to the overlapped state of the first joint section  31  and the second joint section  37 , and as shown in  FIG. 8 , upon attachment of the imaging cartridge  4  to the cartridge receiving section  3  of the apparatus body  1 , it becomes possible to orient both the coupled sections in the respective joint sections in a perpendicular direction. In addition, in both the new toner and the waste toner, the coupled sections  34  and  52  are formed vertically downward from the upstream side to the downstream side in the transportation direction, so that transportation is carried out smoothly in either position. 
     Third Embodiment 
       FIG. 9  shows an imaging cartridge in the third embodiment of the present invention. The imaging cartridge  4  is identical to that of the second embodiment in the point that they are composed of the process unit  50  and the toner bottle  51  and their only difference is the structure of the third joint section  41  and the fourth joint section  42 . That is, the lower surface of the third joint section  41  and the upper surface of the fourth joint section  42  form opposed faces which gradually incline upward toward the top end (right-hand side in  FIG. 9 ), their inclination direction being reverse of the inclination direction of the first joint section  31  and the second joint section  37 . 
     According to this structure, the vertical occupancy space of one end side of the toner bottle, which is constituted of the first joint section  31  and the fourth joint section  42 , is gradually decreased toward the top end, so that easy loading and unloading of the process unit  24  and the toner bottle can be achieved. 
     The present invention is not limited to the embodiments disclosed but accommodates various modifications. Although the present invention has been explained by taking the printer of the direct transfer method as an example, the present invention can also be applied to image forming apparatuses of the indirect transfer method in which a toner image is primarily transferred onto an intermediate transfer belt from each imaging cartridge  4  and the toner image on the intermediate transfer belt is secondarily transferred onto a recording medium. The present invention is also applicable to image forming apparatuses other than printers, such as copying machines, facsimile transceivers and multi-functional machines.