Abstract:
A powder container of the present invention is made up of a deformable bag for storing desired powder and a box more rigid than the bag for accommodating the bag. The bag includes an outlet portion for discharging the power. Despite that the bag is flexible, the powder container does not fall down when mounted to an image forming apparatus. Further, the powder container is easy to assemble and easy to transport at the time of collection. A method of assembling the toner container and an image forming apparatus using the same are also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a powder container, a method of assembling the same and an image forming apparatus. More particularly, the present invention relates to a toner container for storing toner applicable to an electrophotographic image forming apparatus, a method of assembling the same, and a printer, copier, facsimile apparatus or similar image forming apparatus. 
     It has been customary with an image forming apparatus to use a toner container implemented as a cartridge, bottle or similar hard case. The kind of toner container, however, has a problem in the replacement aspect. Specifically, a manufacturer shipped the hard toner container to a user&#39;s station collects the container run out of toner and then recycles, reuses or burns it. The hard toner container needs high distribution costs up to the time of collection. 
     In light of the above, a toner container whose volume can be reduced has been proposed in the past. Such a toner, however, cannot stably replenish toner via a toner replenishing device. While a toner container whose volume can be reduced only during transport has also been proposed, it causes toner to fly about and contaminate surroundings when transferred to a hard bottle or a toner hopper. 
     Further, a toner replenishing device has been proposed that can stably replenish toner even from a toner container implemented by a resin, paper or similar flexible sheet and can replenish it to a developing unit remote from the container. The toner container includes a flexible bag storing toner and is used in an upright position with a toner outlet facing downward. A problem with this configuration is that the flexible bag is apt to fall down due to its own weight to thereby stop up the toner outlet. Further, when the bag collapses due to the consumption of the toner, the resulting creases of the bag catch the toner and cause much toner to be left in the toner container. Moreover, the flexible toner container is difficult to handle at the time of replacement. 
     Technologies relating to the present invention are disclosed in, e.g., Japanese Patent Laid-Open Publication Nos. 7-134484, 9-22175, and 11-119536. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a powder container easy to transport and assemble and falling down little despite the use of a flexible bag, a method of assembling the same, and an image forming apparatus. 
     In accordance with the present invention, a powder container includes a deformable bag for storing powder, and a box more rigid than the bag for accommodating the bag. The box includes an open portion for allowing the bag to be inserted into the bag. 
     Also, in accordance with the present invention, a powder container includes a deformable bag for storing powder, and a box more rigid than the bag for accommodating said the. The box is polyhedral and includes walls having linear sides. Nearby walls include contiguous sides and separate sides. The box is capable of being developed in the form of a flat sheet. 
     Further, in accordance with the present invention, a method of assembling a toner container including a deformable bag for storing powder and a box more rigid than said the for accommodating the bag includes the steps of positioning the bag such that the outlet portion of the bag faces upward, framing the box with only the wall thereof corresponding to one side of the bag left open, inserting the bag into the box via the one side, connecting the bag and box via a connecting device, and closing the open wall to thereby complete the box. 
     Moreover, in accordance with the present invention, an image forming apparatus includes a powder container including a deformable bag for storing powder and a box more rigid than the bag for accommodating the bag. A powder distinguishing devices distinguishes the powder stored in the bag from another powder. 
     In addition, in accordance with the present invention, an image forming apparatus includes a powder container including a deformable bag for storing powder and a box more rigid than the bag for accommodating the bag. A model distinguishing device distinguishes a model of the image forming apparatus to which the box is applicable from another model. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which: 
     FIG. 1 is a view showing a toner replenishing mechanism included in an image forming apparatus embodying the present invention; 
     FIG. 2 is an isometric view showing a specific configuration of a toner container included in the illustrative embodiment; 
     FIG. 3 is a section showing a mouth portion forming part of the toner container; 
     FIG. 4 is an isometric view of the mouth portion; 
     FIG. 5 is a developed view showing the inner periphery of a box forming another part of the toner container; 
     FIG. 6 is a developed view showing the outer periphery of the box; 
     FIG. 7 is a fragmentary section of the box; 
     FIG. 8 is a fragmentary isometric view showing part of the box different from the part shown in FIG. 7; 
     FIG. 9 is a view showing the box in the initial flat position before framing; 
     FIG. 10 is a view showing the box in a medium stage of framing; 
     FIG. 11 is a view showing the box in the final stage of framing; 
     FIG. 12 is a fragmentary section showing part of the box different from the part shown in FIGS. 7 or  8 ; 
     FIG. 13 is a section showing the box and mouth portion; 
     FIG. 14 is an isometric view showing the toner container in a specific complete condition; 
     FIG. 15 is an isometric view showing the toner container in another specific complete condition; 
     FIG. 16 is an isometric view showing an alternative embodiment of the present invention; 
     FIG. 17 is an isometric view showing another alternative embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 and 2, a toner replenishing device included in an image forming apparatus embodying the present invention is shown. As shown, the image forming apparatus includes a developing unit  1  and a toner container  2 . The toner container  2  is a specific form of a powder container and stores powdery toner. In the illustrative embodiment, the toner container  2  is implemented as a bag-in-box type container made up of a deformable bag  20  and a box  50  accommodating the bag  20 . The box  50  is more rigid than the bag  20 . 
     The toner container  2  is a unit separate from the developing unit  1  and removably mounted to a mount portion included in the body of the apparatus from above the apparatus. The mount portion may be positioned within the apparatus such that it is accessible when, e.g., a door or a cover mounted on the apparatus body is opened. Alternatively, the mount portion may be arranged on the outside of the apparatus body. 
     The mount portion includes an upright nozzle  30  capable of penetrating into the toner container  2  when the container is set. The nozzle  30  has a conical tip member  31  molded integrally with, adhered to or otherwise mounted on its top. The nozzle has a double-tube structure defining an air inlet passage  32  and a toner outlet passage  33 , which are contiguous with the tip member  31 . The toner outlet passage  33  is bent to the left, as viewed in FIG. 1, at the bottom of the nozzle  30  and formed with an opening  35  at its end. The air inlet passage  32  is bent to the right, as viewed in FIG. 1, at a level higher than the toner outlet passage  33  and formed with an opening  34  at its end. 
     In the illustrative embodiment, the opening  34  of the air inlet passage  32  is communicated to an air pump or air feeding means  40  by a pipe  41 . The air pump  40  delivers air under pressure into the toner container  2  via the pipe  41  and air inlet passage  32 . Air jetted into the toner container  2  passes through a toner layer and fluidizes the toner layer by scattering it. 
     A suction type powder pump  3  is located in the vicinity of or constructed integrally with the developing unit  1 . The powder pump  3  is a single axis, eccentric screw pump and made up of a rotor  4 , a stator  5  and a holder  6 . The rotor  4  is made of metal or similar rigid material and provided with an eccentric, screw-like configuration. The stator  5  is formed of rubber or similar elastic material and provided with a double-screw configuration. The holder  6  accommodates the rotor  4  and stator  5  therein in such a manner as to form a toner passage and is formed of, e.g., resin. A toner outlet  7  is formed at the left end of the holder  6 , as viewed in FIG. 1. A pipe  8  provides fluid communication between the toner outlet  7  and a toner inlet, not shown, formed in the developing unit  1 . 
     A buffer or toner storing means  10  is connected to the inlet side of the powder pump  3  in order to store an adequate amount of toner. A screw or toner conveying means  11  is disposed in the buffer  10  and protrudes to the outside of the buffer  10  at one end. A drive source, not shown, is drivably connected to the protruding end of the screw  11 . The other end of the screw  11  is connected to the rotor  4 . In this configuration, the powder pump  3  and screw  11  are caused to operate at the same time as each other. 
     A toner inlet  12  is formed in the buffer  10 . A flexible tube  15  communicates the toner inlet  12  to the opening  35  of the nozzle  30 . The tube  15  has a diameter of, e.g., 4 mm to 10 mm and is formed of polyurethane, nitril, EPDM, silicone or similar rubber highly resistant to toner. The tube  15  with flexibility can be easily laid in any desired direction, i.e., upward, downward, rightward or leftward. 
     In the toner replenishing device having the above configuration, the powder pump or screw pump  3  can continuously deliver toner with a high solid-to-gas ratio by an accurate, constant amount, which is proportional to the rotation speed of the rotor  4 , as well known in the art. In response to a replenishment command derived from, e.g., sensed image density, the powder pump  3  is operated to replenish a required amount of toner to the developing unit  1 . The powder pump  3  may not include the buffer  10  or may be replaced with a discharge type powder pump, if desired. 
     The toner container  2  will be described more specifically with reference to FIG.  2 . As shown, the bag  20  is made up of a mouth portion  21  and a bag portion  22  affixed to the mouth portion  21 . The mouth portion  21  is formed of, e.g., resin by blow molding or similar technology and includes a toner outlet. The bag portion  22  is implemented by a flexible sheet or a laminate of flexible sheets formed of polyethylene, nylon or similar resin and 80 μm to 200 μm thick each. 
     As shown in FIGS. 3 and 4, the mouth portion  21  includes a through hole  24  extending in the up-and-down direction and forming the toner outlet. A flat slider  25  is affixed to or formed integrally with the outer periphery of the wall that forms the through hole  24 . The slider  25  is generally rectangular and constitutes projections forming part of connecting means. The bag portion  22  is affixed to a boat-shaped protuberance  26 , which is also included in the mouth portion  21  above the slider  25 . An outlet portion  27  is positioned below the slider  25  and forms the through hole  24 . A seal valve or self-closing valve  23  is fitted in the outlet portion  27  and formed of an elastic material, preferably foam sponge. A cap  28  is formed integrally with the mouth portion  21  via a connecting portion  29  in order to close the outlet portion  27 . A circular recess  28   a  is formed in the cap  28  and capable of mating with the outlet portion  27 . 
     FIGS. 5 and 6 respectively show the inner periphery and outer periphery of the box  50  in developed views. As shown, the box  50  has eight walls  50   a  through  50   h.  The walls  50   a  through  50   h  have straight sides contiguous with each other and straight sides separate from each other, and each has at least one side contiguous with the side of the adjoining wall. Therefore, by suitably selecting the contiguous sides and separate sides of the walls  50   a  through  50   h,  it is possible to develop the box  50  in the form of a single sheet having any one of various shapes. The contiguous sides prevent the walls  50   a  through  50   h  from fully parting from each other at the time of development. 
     As shown in FIG. 7, a V-shaped groove  51  is formed in each of the contiguous sides of the walls  50   a  through  50   h  in order to limit a foldable angle. The angle of the letter V is selected in accordance with the angle by which each contiguous side is to be folded. For example, when the angle of the letter V is 90 degrees, nearby walls contiguous with each other via the groove  51  can be folded by substantially 90 degrees in the direction in which the surfaces forming the letter V contact each other. On the other hand, the nearby walls can be folded up to contact each other when folded in the other direction in which the surfaces forming the letter V move away from each other. 
     As shown in FIG. 8, tongues  52  (only one is shown) protrude from one of the adjoining separate edges of the walls  50   a  through  50   h.  Recesses  53  (only one is shown) are formed in the other of the adjoining separate edges of the walls  50   a  through  50   h.  The tongues  52  and recesses  53  constitute fastening means for fastening nearby walls  50   a  through  50   h.  To frame the box  50 , the walls  50   a  through  50   h  in the form of a flat sheet are folded inward in a suitable sequence with the tongues  52  mating with the recesses  53 . The box  50  can therefore be framed without resorting to any tool. 
     FIG. 9 shows the box  50  in a developed position with the outer surfaces of the box  50  facing upward. As shown in FIG. 10, the box  50  in the position shown in FIG. 9 is folded in two such that the wall  50   c  lies on the wall  50   f.  As a result, the widthwise dimension of the box  50  is halved. Subsequently, as shown in FIG. 11, the wall  50   g  protruding downward from the box  50  is folded. The box  50  so folded up is small and thin enough to be put in an envelope  59  having a suitable size. As for the wall  50   g  folded last, a margin available with the V-shaped groove  51  at the time of folding is short. For this reason, as shown in FIG. 12, a groove  54  in the form of a letter W is formed in the contiguous side of the wall  50   g.    
     The mouth portion  21  of the bag  20  is fitted to the wall  50   d  of the box  50 . As shown in FIG. 3, guide portions  58  are formed integrally with the wall  50   d  in order to receive the slider  25  of the mouth portion  21  while guiding the slider  25 . 
     The bag  20  is fitted to the box  50  by the following procedure. As shown in FIG. 2, the walls  50   c  through  50   h  are folded in the form of a box while the walls  50   a  and  50   b  are left flat. The bag  20  has its outlet portion  27  closed by the cap  28  in order to prevent the toner from leaking, as indicated by a dash-and-dots line in FIG.  13 . Subsequently, the slider  25  of the mouth portion  21  is slid into the guide portions  58 . In this manner, the bag  20  is easily received in the box  50 . Thereafter, the walls  50   a  and  50   b  are folded to fully frame the box  50 . At this instant, the tongues  52  and recesses  53  are caused to mate with each other between the walls  50   a  and  50   b  and the wall  50   h.    
     As shown in FIG. 14, to prevent the walls  50   a  and  50   b  from easily unfolding, a seal  60  may be wrapped around all the side surfaces of the toner container  2 . The seal  60  may be implemented by a thermally shrinkable seal by way of example. Further, the seal  60  may be provided with a shrink wrap  61  in order to allow the box  50  to be easily unfolded by hand. As shown in FIG. 15, the seal  60  may be replaced with an adhesive seal  62  adhered to the walls  50   a  and  50   b  folded last and the wall  50   h.    
     As shown in FIG. 13, the wall  50   a  is formed with a fitting portion  55  for fitting the cap  28 . When the toner container  2  is to be used, the cap  28  is removed from the outlet portion  27  and then fitted in the fitting portion  55 , as indicated by a solid line in FIG.  13 . This prevents the cap  28  from obstructing the operation for mounting the toner container  2  to the apparatus body. 
     When the toner container  2  set on the apparatus body runs out of toner, it is picked up from the apparatus body. After the seal, if present, has been removed, the empty bag  20  is released from the box  50 . The box  50  can be folded up in a small size and is therefore easy to transport or store while occupying a minimum of space. This noticeably reduces the cost necessary for the box  50  to be distributed from the user&#39;s station to the manufacturer&#39;s station. Moreover, if the box  50  is formed of a material having certain durability, then it can be repeatedly used a plurality of times and therefore contributes a great deal to cost reduction. 
     The bag  20  is burned for reuse or similar purpose. The flexible bag portion  22  is empty and can therefore be transported or otherwise dealt with at an extremely low cost like the box  50 . 
     There are available toner of various colors and various properties. If inadequate toner is used, the entire developing unit must be replaced in the worst case. Particularly, it is a common practice with a full-color image forming apparatus to use toner of three different colors and black toner, which is consumed more than the other toner. A toner container storing the black toner is, in many cases, greater in size than toner containers storing the other toner. However, the toner containers storing the three color toner are identical in size, so that a person is apt to select a wrong toner container. 
     In light of the above, in the illustrative embodiment, mating means of a particular color is assigned to each mount portion of the apparatus body and corresponding one of the toner containers. This prevents each toner container from being set in an unexpected mount portion. As best shown in FIG. 2, the mating means, or toner distinguishing means, is implemented by arcuate recesses  57  formed in the box  50  and capable of mating with projections, not shown, positioned in a preselected mount portion included in the apparatus body. The position of the recesses  57  differs from one toner to another toner. 
     Alternatively, the recesses  57  may be formed in the slider  25  of the mouth portion  21 , although not shown specifically. The recesses  57  formed in the slider  25  are advantageous over the recesses  57  formed in the box  50  in that it is not necessary to fabricate a particular box  50 , which is repeatedly usable, for each color. 
     Generally, image forming apparatuses of the same model are used in various countries. While such apparatuses can share the same toner container  2 , the production cost of the toner container  2  is dependent on the economical circumstances of each country. Therefore, if toner produced at low cost is used in countries where the production cost is high, then the distribution system is disturbed. To solve this problem, the illustrative embodiment additionally includes recesses  56  formed in the box  50  and playing the role of model distinguishing means. The model distinguishing means limits the model of an image forming apparatus to which the toner container  2  is applicable. In this case, each apparatus body is provided with projections, not shown, capable of mating with the recesses  56  at a particular position. 
     FIG. 16 shows an alternative embodiment of the present invention. As shown, a box  50 ′ is openable in a right-and-left direction like a bivalve. The box  50 ′ should preferably be openable along a diagonal line, as seen from the above, so that it can be widely opened to further facilitate the attachment of the bag not shown. Although the box  50 ′ cannot be developed, it also saves space if a plurality of such boxes are stacked in the opened position. 
     FIG. 17 shows another alternative embodiment of the present invention. As shown, a box  50 ″ is constantly open at a portion corresponding to one wall, i.e., one side wall in the illustrative embodiment. The box  50 ″ allows even the operator of the apparatus to easily attach and detach the bag  20  from the box  50 ″. Specifically, the walls  50   a  and  50   b  of the previous embodiment are absent in the box  50 ″, so that the box  50 ″ can be developed or folded up in a small size. 
     As stated above, the bag  20  of the toner container  2  is flexible while the box  50  can be folded up in a small size or developed in the form of a flat sheet. The toner container  2  is therefore easy to handle at the time of transport or storage while saving space, compared to a hard case. The bag  20  is collected by the manufacturer and then recycled, reused or burned. The box  50  with the above advantages noticeably reduces the cost necessary for the collection and distribution thereof. The mouth portion  21 , bag portion  22  and seal valve  23  of the bag  20  should preferably be formed of the same material or materials belonging to the same series, so that they do not have to be classified at the time of recycling. 
     In summary, it will be seen that the present invention provides a toner container including a flexible bag accommodated in a box. The box prevents the flexible bag from falling down when set on an image forming apparatus. Further, the box is foldable and therefore reduces the collection and distribution costs of the toner container to a significant degree. Moreover, the box is easy to fold and unfold and can be repeatedly used. 
     Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.