Abstract:
An image forming apparatus including: an image forming apparatus main unit; an image carrier provided in the image forming apparatus main unit; at least one developing device supported retractable from the image carrier; and a developer supply portion adapted to supply developer to the developing device, wherein: a developer inlet port provided in the developing device is slidably joined with a developer supply port provided in the developer supply portion; a seal portion is provided between the developer inlet port and the developer supply port; the seal portion includes a seal portion body made of an elastic material, a sliding portion provided on at least one of surfaces of the seal portion body, and a drawing-out portion connected to the seal portion body and to the sliding portion; and the seal portion is enabled to be drawn out by using the drawing-out portion.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an image forming apparatus, such as a printer, a facsimile, and a copying machine, and to a seal portion for use in the image forming apparatus.  
         [0003]     2. Background Art  
         [0004]     An image forming apparatus has, within an image forming apparatus main unit thereof, an image carrier constituted by, for example, a photoreceptor, an optical writing device adapted to form a latent image on this image carrier, and a developing device adapted to visualize the latent image formed on the image carrier by this optical writing device. A developer supply portion supplies developer to the developing device. There has been known one such a developing device which is disposed retractable from the image carrier and which is adapted to be retracted, for instance, in a case where the image carrier is exchanged, thereby to prevent the image carrier from being damaged, for example, being scratched. In the case where the developing device is retracted, a developer inlet port provided in the developing device is slidably joined with a developer supply port provided in the developer supply portion.  
         [0005]     Incidentally, JP-A-2002-341650 discloses technology of applying a film member to an elastic member fixed to the periphery of at least one of openings, which are respectively provided in two casings so that developer is transferred therebetween, thereby to enhance slidability at opening/closing of the opening portions of the two casings and also enhance ability to seal the leakage of toner. Also, Japanese Patent No. 3054323 discloses technology of pasting an elastic member onto a sliding portion, which slides through a guide portion of an openable and closable shutter of a refill toner container, and also coating a film member, which is applied to a sliding surface of the sliding portion, with a coating layer made of a silicon based material so that the container has good slidability at opening/closing of the shutter and excels in ability to seal the leakage of toner.  
         [0006]     At shipping inspection of an image forming apparatus, developer is supplied into a developing device. Then, an image is printed on test paper by using the developer stored in the developing device. However, there has been caused a problem that the developer stored in the developing device leaks from the developer inlet port, the developer supply port, and the sliding portion during the image forming apparatus is transported after the shipping inspection. Neither JP-A-02-341650 nor Japanese Patent No. 3054323 discloses how to assure sealability against the leakage of developer from the developer inlet port, the developer supply port, and the sliding portion.  
       SUMMARY OF THE INVENTION  
       [0007]     An object of the invention is to provide an image forming apparatus, which is enabled to assure sealability against the leakage of developer from the developer inlet port, the developer supply port, and the sliding portion and also enabled to facilitate the shipping inspection thereof, and is to provide a seal portion for use in the image forming apparatus.  
         [0008]     According to a first aspect of the invention, there is provided an image forming apparatus, which includes an image forming apparatus main unit, an image carrier provided in the image forming apparatus main unit, at least one developing device supported retractable from the image carrier, and a developer supply portion adapted to supply developer to the developing device. This image forming apparatus features that a developer inlet port provided in the developing device is slidably joined with a developer supply port provided in the developer supply portion, that a seal portion is provided between the developer inlet port and the developer supply port, that the seal portion includes a seal portion body made of an elastic material, a sliding portion provided on at least one of surfaces of the seal portion body, and a drawing-out portion connected to the seal portion body and to the sliding portion, and that the seal portion is enabled to be drawn out by using the drawing-out portion. Thus, the sealability can be assured by providing the seal portion between the developer inlet port and the developer supply port, which slide with respect to each other. Additionally, this seal portion has the sliding portion and the drawing-out portion. Thus, the shipping inspection of the image forming apparatus can be performed by leaving the seal portion untouched. Also, the seal portion can easily be drawn out by holding the drawing-out portion and using the sliding portion. Consequently, the shipping inspection can easily be completed.  
         [0009]     Preferably, the sliding portion of the seal portion is disposed to face a sliding part of each of the developer inlet port and the developer supply port. Consequently, the slidability between the developer inlet port and the developer supply port can be enhanced.  
         [0010]     Preferably, the developing device has an auger adapted to convey developer inputted from the developer inlet port. Also, the sliding portion of the seal portion is disposed to face the auger. Consequently, the slidability between the sliding portion of the seal portion and the auger can be enhanced.  
         [0011]     Preferably, the image forming apparatus has a plurality of the developing devices. Also, the seal portions are disposed in the plurality of the developing devices, respectively, and are collectively drawn out therefrom by using one jig. Thus, the plural seal portions can be drawn out by using one jig. Consequently, workability can be improved.  
         [0012]     Preferably, the sliding portion and the drawing-out portion are formed of flexible film integrally with each other. Thus, the sliding portion and the drawing-out portion are formed integrally with each other. Consequently, as compared with a case that the sliding portion and the drawing-out portion are formed separately from each other, the number of components can be reduced.  
         [0013]     According to a second aspect of the invention, there is provided a seal portion for use in an image forming apparatus, which is adapted to seal a developer inlet port, which is provided in a developing device, and a developer supply port provided in a developer supply portion. The seal portion includes a seal portion body made of an elastic material, and also includes a sliding portion, which is provided on at least one of side surfaces of the seal portion body, and a drawing-out portion connected to the seal portion body and to the sliding portion. The seal portion can be drawn out therefrom by using this drawing-out portion. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     These and other objects and advantages of this invention will become more fully apparent from the following detailed description taken with the accompanying drawings in which:  
         [0015]      FIG. 1  is a side view illustrating an image forming apparatus according to an embodiment of the invention;  
         [0016]      FIG. 2  is a cross-sectional view illustrating a developing device used in the image forming apparatus according to the embodiment of the invention;  
         [0017]      FIG. 3  is a cross-sectional view illustrating the developing device and a developer supply portion, which are used in the image forming apparatus according to the embodiment of the invention;  
         [0018]      FIG. 4  is a side view illustrating the developing device and the developer supply portion, which are used in the image forming apparatus according to the embodiment of the invention;  
         [0019]      FIG. 5  is a side view illustrating the developing device used in the image forming apparatus according to the embodiment of the invention;  
         [0020]      FIG. 6  is a side view illustrating the developer supply portion used in the image forming apparatus according to the embodiment of the invention;  
         [0021]      FIG. 7  is a cross-sectional view illustrating the developing device and a part of the developer supply portion, which are used in the image forming apparatus according to the embodiment of the invention;  
         [0022]      FIG. 8  is a side view illustrating a seal portion used in the image forming apparatus according to the invention;  
         [0023]      FIG. 9  is a perspective view illustrating the seal portion used in the image forming apparatus according to the invention; and  
         [0024]      FIG. 10  is an enlarged cross-sectional view illustrating the developing device, the seal portion, and the developer supply portion, which are used in the image forming apparatus according to the embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     An embodiment of the invention is described hereinbelow with reference to the accompanying drawings.  
         [0026]      FIG. 1  shows an outline of an image forming apparatus  10  according to an embodiment of the invention. The image forming apparatus  10  has an image forming apparatus main unit  12 . A paper supply unit  14  is provided in a lower portion of this image forming apparatus main unit  12 . Also, a first ejection tray  16  is provided on the top surface of the image forming apparatus main unit  12 . A second ejection tray  18  is provided on the left side surface of the image forming apparatus main unit  12  and faces this first ejection tray  16 . Also, a manual feed tray  20  is provided on the left-side lower portion of the image forming apparatus main unit  12 .  
         [0027]     The paper supply unit  14  has a paper tray  22 , on which sheets of paper are stacked, and a paper supply roll  24  adapted to feed out sheets of paper from this paper tray  22 . The sheet of paper fed out of this paper supply roll  24  is transported on a paper supply path  30  through conveying rolls  26  and  28  to a transfer roll  74  (to be described later). A toner image is transferred by this transfer roll  74 . The toner image is fixed by a fixing roll  32 . The first ejection tray  16  or the second ejection tray  18  is selected according to the position of a switch claw  34 . The sheet of paper is ejected by an ejection roller  36  or  38 . The sheet of paper is ejected to the first tray  16  with the sheet&#39;s side on which the toner image is fixed as the back face thereof. The sheet of paper is ejected to the second tray  18  with the sheet&#39;s side, on which the toner image is fixed, as the front face thereof.  
         [0028]     Incidentally, in the case of double-sided printing, when the sheet of paper is about to be ejected to the first ejection tray  16 , the ejection roll  36  is reversely rotated to thereby supply the sheet of paper to a reverse path  40 . Thereafter, the sheet of paper is returned to the paper supply path  30  by using conveying rolls  42 ,  44 ,  46 , and  48 . Then, the back face of the sheet of paper is printed. The sheets of paper stacked on the manual feed tray  20  are supplied by a manual feed roll  49  and are transported to the paper supply path  30  through the conveying roll  48 .  
         [0029]     A photoreceptor unit  50  has four photoreceptors  52  that are used corresponding to, for example, yellow, magenta, black, and cyan light, respectively, and that are longitudinally arranged from the top, as viewed in this figure. This photoreceptor unit  50  is provided with sets of a refresh roll  54  and a charging roll  56 , which rotate in contact with a corresponding one of the photoreceptors  52 .  
         [0030]     A developing device unit  58  is disposed at the right side of the photoreceptor unit  50 , as viewed in this figure. The developing devices  60  of the developing device unit  58  are longitudinally arranged corresponding to the photoreceptors  52 , respectively. The developing device  60  employs what is called a trickle developing system, so that excessive developer is collected into a collection container. An exposure unit  62  is disposed at the right side of this developing device unit  58 . Four laser light beams according to an image signal are emitted from this exposure unit  62 , so that a latent image is formed on the photoreceptors  52 . Four developer cartridges  64  are disposed at the right side of this exposure unit  62 , as viewed in this figure. The developer cartridges  64  and the developing devices  60  are connected through developer supply portions (to be described later) so that developer is supplied from the developer cartridges  64  to the developing devices  60 .  
         [0031]     An intermediate transfer unit  66  is disposed at the left side of the photoreceptor unit  50 , and has three drum-like intermediate transfer bodies  68 ,  70 , and  72 . The two first transfer bodies  68  and  70  are longitudinally arranged. An upper one of the first intermediate transfer bodies  68  rotates in contact with the two upper photoreceptors  52  and  52 . A lower one of the first intermediate transfer bodies  70  rotates in contact with the two lower photoreceptors  52  and  52 . The second intermediate transfer body  72  rotates in contact with both the first intermediate transfer bodies  68  and  70 . The transfer roll  74  rotates in contact with this second intermediate transfer body  72 . Thus, toner images respectively having two colors are transferred from the two sets of the two photoreceptors  52  and  52  to the first intermediate transfer bodies  68  and  70 , respectively. The toner images of two colors transferred to each of the first intermediate transfer bodies  68  and  70  are then transferred to the second intermediate transfer body  72 , so that a toner image of four colors is obtained. This toner image of four colors is transferred by this transfer roll  74  onto a sheet of paper. A cleaning roll  76  and a cleaning brush  78  are disposed at each of the intermediate transfer bodies  68 ,  70 , and  72 . Toner caught by the cleaning roll  76  is scraped off by, for instance, a blade. The scraped-off toner is collected into a collection container (not shown).  
         [0032]      FIG. 2  shows a practical example of the aforementioned developing device  60 . As described above, the developing device  60  employs what is called the trickle developing system. A magnet roll  82  and two spiral augers  84  are rotatably supported in a developing device main unit  80 . The two augers  84  rotate in opposite directions, respectively, and are partitioned by a wall  86  formed n the developing device main unit  80 . The augers  84  are connected to each other through circulating ports  88  and  88  respectively formed in the vicinities of both end portions thereof. Developer put into the developing device main unit  80  from a developer inlet port  90  is circulated in the developing device main unit  80  and is supplied to the magnet roll  82 . A step-like portion  92  constituting a collection developer generating portion is formed at one end portion of the developing device main unit  80 . A part of the circulated developer is taken into this step-like portion  92 . Then, the taken-in developer is sent to a discharge portion  94  that is connected to a collection port of a collection container (not shown). Also, an input gear  96  for driving the developing device  60  is provided at the other end portion of the developing device main unit  80 . The magnet roll  80  and the augers  84  are rotated by being driven by the input gear  96 .  
         [0033]     FIGS.  3  to  7  show a connection portion between the developing device  60  and the developer supply portion  98  in detail.  
         [0034]     The developer supply portion  98  has a developer supply portion main unit  100  made of, for instance, POM (polyacetal). This developer supply portion main unit  100  is fixed to the aforementioned image forming apparatus main unit  12 . For example, two pins  102  and  102  are formed on the back surface of this developer supply portion main unit  100  in such a way as to protrude therefrom, as shown in  FIG. 6 . For instance, two elongated holes  104  and  104  are formed in an end surface of the developing device main unit  80 , as shown in  FIG. 5 . The pins  102 ,  102  of the developer supply portion  98  are slidably engaged with the two elongated holes  104  and  104  of the developing device  60 , respectively. The developing device  60  is slidably supported by the developer supply portion  98 , as shown in  FIG. 7 .  
         [0035]     The developer supply portion  98  is configured so that the connection portion  106  is formed integrally with the developer supply portion main unit  100 . A connection port  108  is formed at an end of this connection portion  106 . An end of a connection hose  110  is connected to this connection port  108 . The other end of this connection hose  110  is connected to the aforementioned developer cartridge. Developer is supplied from the developer cartridge through this connection hose  110 . Also, a developer supply port  112  opened downwardly is formed in the connection portion  106 . This developer supply port  112  is joined with the developer inlet port  90  of the developing device  60  in such a manner as to be fitted to the port  90 . As described above, the developing device  60  slides with respect to the developer supply portion  98 . Thus, the developer inlet portion  90  is adapted to slide in a state in which the inlet portion  90  is fitted to the developer supply port  112 . As indicated by an arrow shown in  FIG. 7 , the developing device  60  is moved from a position, which is indicated by solid lines, to another position indicated by dashed lines, so that the aforementioned magnet roll is put into contact with or is made to come closer to the photoreceptor.  
         [0036]     An end of the aforementioned auger  84  faces the developer inlet port  90 . Developer inputted from the developer inlet port  90  is conveyed into the developing device  60  by rotation of the auger  84 .  
         [0037]     In the developing device  60  and the developer supply portion  98 , which are configured in this way, there is a fear that developer may leak from between the developer inlet port  90  and the developer supply port  112  during the image forming apparatus  1  is transported. Thus, in this embodiment, a seal portion  114  shown in  FIGS. 8 and 9  is provided as a seal member used during the image forming apparatus  1  is transported.  
         [0038]     The seal portion  114  has a seal portion body  116  and upper and lower sliding portions  118  and  120  provided in such a way as to cover this seal portion body  116 . The seal portion body  116  is made of an elastic material, for example, urethane foam, and is formed like a rectangular parallelepiped. The outer shape of the seal portion body  116  is formed in such a way as to be slightly larger than the inner shape of the developer inlet port  90 . The seal portion body  116  is fitted into the developer inlet port  90  by being compressed. The lower sliding portion  118  is made of a flexible material, for example, PET (Poly-Ethylene Terephthalate) film. This lower sliding portion  118  is substantially equal to the seal portion body  116  in width, and is bonded to the bottom surface of the seal portion body  116  by an adhesive. The lower sliding portion  118  extends upwardly from the bottom of the seal portion body  116  to a substantially central position of each of the front surface and the rear surface thereof, as viewed in the figures. Thus, the lower sliding portion  118  is bonded to the surface of the lower part of the seal portion body  116 , which extends downwardly from the substantially central position of each of the front surface and the rear surface. An end part of the lower sliding portion  118  extends more frontwardly from the substantially center of the front surface of the seal portion body  116  and is connected to a drawing-out portion  122  (to be described later). The other end part of the lower sliding portion  118  extends rearwardly from the substantially center of the rear surface of the seal portion body  116  and behaves as a free end. On the other hand, the upper sliding portion  120  is made of a flexible material, for example, PET (Poly-Ethylene Terephthalate) film, similarly to the lower sliding portion  118 . This upper sliding portion  120  is substantially equal to the seal portion body  116  in width, and has an end part connected to the drawing-out portion  122 , similarly to the lower sliding portion  118 . The other end part of the upper sliding portion  120  is placed above the seal portion body  116  and extends more rearwardly from the rear end of the seal portion body  116  and behaves as a free end.  
         [0039]     The drawing-out portion  122  is made of PET film, which is a flexible material, and is formed integrally with the lower sliding portion  118  and the upper sliding portion  120 . An insertion hole  124  is formed in such a way as to penetrate through the drawing-out portion  122  in an up-down direction. As shown in  FIG. 10 , a jig  126  is inserted into this insertion hole  124 .  
         [0040]     As shown in  FIG. 10 , the seal portion  114  is disposed between the developer inlet port  90  of the developing device  60  and the developer supply port  112  of the developer supply portion  98 . That is, the seal portion body  116  is compressed and fitted into the developer inlet port  90 . The lower sliding portion  118  is brought into contact with the auger  84 . The upper sliding portion  120  is put into contact with the developer supply port  112 . The drawing-out portion  122  protrudes frontwardly from a joint portion between the developer inlet port  90  and the developer supply port  112 . In a case where the seal portion  114  is mounted, the seal portion body  116  and the lower sliding portion  118  are fitted into the developer inlet port  90  of the developing device  60  so that the seal portion body  116  of the seal portion  114  is compressed. At that time, the free ends of the upper and lower sliding portions  120  and  118  are lined up. Thus, it can be checked whether the seal portion  114  is properly mounted in the developer inlet port  112 . Subsequently, the pins  104  and  104  of the developer supply portion  98  are inserted into the elongated holes  102  and  102  of the developing device  60  are supported in such a way as to be able to slide with respect to the developer supply portion  98 . Consequently, the seal portion body  116  is further compressed between the developing device  60  and the developer supply portion  98 , so that the seal portion  114  can be mounted, as shown in  FIG. 10 , and that this seal portion  114  can seal between the developer inlet port  90  and the developer supply port  112 .  
         [0041]     Thus, even in a case where the image forming apparatus  10  undergoes vibrations due to the transportation thereof in a state in which this seal portion  114  is mounted, the seal portion  114  is disposed between the developer inlet port  90  of the developing device  60  and the developer supply port  112  of the developer supply portion  98 . The seal portion body  116  is compressed and is brought into close contact with the developer inlet port  90  and the developer supply port  112 . Consequently, the developer can be prevented from leaking from the joint portion between the developer inlet port  90  and the developer supply port  112 .  
         [0042]     Thus, even in a state in which the seal portion  114  is mounted, the auger  84  is in contact with the lower sliding portion  118  of the seal portion  114 . This can assure the rotation of the auger  84 . Therefore, in a state in which the seal portion  114  is mounted, a test image can be outputted by using a small amount of developer put into the developing device  60 . Because the upper sliding portion  120  is disposed between the developing device  60  and the developer supply portion  98 , the sliding motion of the developing device  60  can be assured, as shown in  FIG. 7 . Also, the retracting motion of the developing device  60  can be tested.  
         [0043]     Next, a method of drawing out the seal portion  114  is described hereinbelow.  
         [0044]     As shown in  FIG. 10 , in a state in which the seal portion  14  is mounted, the drawing-out portion  122  protrudes frontwardly from the developing device  60  and the developer supply portion  98 . In this embodiment, the drawing-out portion  122  of each of the four seal portions  114 , which respectively correspond to the four developing devices  60 , protrudes frontwardly from the corresponding developing device  60 . Thus, as indicated by double-dashed chain lines shown in  FIG. 2 , the jig  126  is inserted into the insertion hole  124  formed in the drawing-out portion  122 . Then, this jig  126  is frontwardly drawn. Thus, the seal portion body  116  of the seal portion  114  is compressed still more. Also, the upper and the lower sliding portions  120  and  118  enable the seal portion  114  to slide between the developing device  60  and the developer supply portion  98 . Consequently, the four seal portions  114  can collectively be drawn out from between the developing devices  60  and the developer supply portions  98 .  
         [0045]     As described above, the invention can be utilized in an image forming apparatus that undergoes vibrations during the transportation thereof.