Patent Publication Number: US-7899371-B2

Title: Image forming and toner supply apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of application Ser. No. 11/435,515 filed May 17, 2006, the entire contents of which is hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an image forming apparatus to detachably support a toner supply container to supply toner to a developing device in an image forming apparatus using an electro-photographic process such as copying machine, printer, etc. 
     DESCRIPTION OF THE BACKGROUND 
     In an image forming apparatus using an electro-photographic process such as copying machine, printer, etc., toner is supplied to a developing device. There is a toner bottle of which top is inserted directly into a toner supply mechanism at the main body side of an image forming apparatus to supply toner by rotating with the driving of the supply mechanism. The toner bottle emptied after supplying toner is pulled out from the main body of an image forming apparatus and exchanged with a new toner bottle. The inserting portion of such a toner bottle is formed thinner than the toner containing portion. That is, there is a step produced between its toner containing portion and the inserting portion. 
     To exchange such a toner bottle with a new one, the emptied bottle is pulled out from the main body of an image forming apparatus by sliding it along a stay supporting a toner bottle in the main body of the image forming apparatus. And in order to prevent toner from spilled out from a toner bottle when exchanging it with a new bottle, a shutter is provided at a toner discharging port of the toner bottle. 
     However, in case of a conventional image forming apparatus, as there is a step between the toner containing portion and the inserting portion of a toner bottle, the inserting portion of a toner bottle is struck against the inserting portion of the stay when a toner bottle is pulled out from the main body of an image forming apparatus. As a result, there was such a trouble caused to contaminate the inside of the main body of the image forming apparatus at the near portion of the inserting port of the stay by the toner adhered to the inserting portion dropped by the shock even if there is a shutter provided at the toner discharging port. 
     So, an image forming apparatus capable of preventing its inside from being contaminated by toner by preventing toner adhered to a toner bottle from dropping by the shock when pulling out a toner bottle by sliding it along the stay is desired. 
     SUMMARY OF THE INVENTION 
     Accordingly, an advantage of the present invention is to provide an image forming apparatus without causing the drop of toner adhered to a toner bottle even when pulling out a toner bottle by sliding it along the stay when exchanging it with a new toner. 
     To achieve the above advantage, one aspect of the present invention is to provide an image forming apparatus, comprising a toner supply mechanism to supply toner to a developing device; a supporting member to support a detachable toner supply container to the toner supply mechanism detachably; and a buffering member swingably projected from the bottom surface of the inserting port side of the supporting member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic construction diagram showing a copying machine in a first embodiment of this invention; 
         FIG. 2  is a side view showing a toner bottle in the first embodiment of this invention; 
         FIG. 3  is a schematic perspective view showing the attaching/detaching to/from a toner bottle of a copying machine in the first embodiment of this invention; 
         FIG. 4  is a schematic perspective view showing the inserting side frame in the first embodiment of this invention; 
         FIG. 5  is a schematic perspective view showing the inserting side frame in a second embodiment of this invention: 
         FIG. 6  is a schematic perspective view showing the inserting side frame in a third embodiment of this invention; 
         FIG. 7  is a schematic perspective view showing the inserting side frame, a the bottle stay and a toner supply device in a fourth embodiment of this invention; 
         FIG. 8  is a schematic explanatory diagram showing the state of a cap portion installed to a cap guide in the fourth embodiment of this invention. 
         FIG. 9  is a schematic perspective view showing the inserting side frame in a fifth embodiment of this invention; 
         FIG. 10  is a schematic perspective view showing the inserting side frame in a sixth embodiment of this invention; and 
         FIG. 11  is a schematic explanatory diagram showing the cap portion in a seventh embodiment of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Hereinafter, the first embodiment of this invention will be explained in detail referring to the attached drawings.  FIG. 1  is a schematic construction diagram showing a copying machine  10  that is an image forming apparatus in the first embodiment of this invention. A scanner  11  is provided on a document reading glass  11   a  above copying machine  10  to read documents placed on document reading glass  11   a  or documents conveyed by an automatic document feeder  12 . 
     Below scanner  11  and separated from copying machine  10  by a paper discharging portion  13  in the main body, there are a photosensitive drum  1 , a main charger  2  which uniformly charges photosensitive drum  1  sequentially according to the rotating direction of an arrow mark q of photosensitive drum  1 , a laser exposing unit  7  to form a latent image by irradiating laser light  7   a  to charged photosensitive drum based on image data from scanner unit  11 , a developing unit  3 , a transfer/separating charger  4 , a cleaner  5 , and a charge eliminating LED  6  provided. Developing unit  3  is a magnetic brush type developing unit well-known so far to make the development using two-component developing agents comprising toner and carrier. Developing unit  3  is supplied with toner by a toner bottle  26  that is a toner supply container installed above the unit according to toner density in the developing agent. At the rear side of copying machine  10 , a toner supply unit  27  is provided. Toner supply unit  27  conveys toner supplied from toner bottle  26  and supplies it to developing unit  3 . 
     Under copying machine  10 , a paper supply cassette  14  is provided to supply sheet paper P in the direction of transfer position of photosensitive drum  1 . Further, copying machine  10  is equipped with a paper supply tray  14  to manually supply sheet paper P and a reverse conveying mechanism  17  to reverse sheet paper P in the both side image forming.  18  is an aligning roller to align the leading edges of sheet paper P supplied from paper supply cassette  14 , paper supply tray  16  or reverse conveying mechanism  17  and conveys sheet paper P in the direction of photosensitive drum  1  in synchronous with a toner image. At the downstream of the transfer position of photosensitive drum  1 , a fixing device  22  that is a fixing unit is provided to heat, pressurize and fix a toner image by conveying sheet paper P while clamping paper with a heat roller  20  and pressure roller  21 . At the downstream of fixing device  22 , a paper discharging roller  24  is provided to discharge sheet paper P after fixing to a paper discharging unit  13 . 
     Next, a toner bottle  26  and its supporting member will be explained in detail. Toner bottle  26  has a nearly cylindrical shape toner containing portion  26   a  and a cap portion  26   b  that is attached to a toner supply unit  27  as shown in  FIG. 2 . Around toner containing portion  26   a , a spiral shape conveying groove  26   c  is formed. When toner bottle  26  is rotated by the driving of toner supply unit  27 , toner in toner containing portion  16   b  is guided to conveying groove  26   c  and conveyed in the direction of cap portion  26   b.    
     Cap portion  26   b  is thinner than toner containing portion  26   a  and produces a step α between it and toner containing portion  26   a . Between toner containing portion  26   a  and cap portion  26   b  becomes a step-like inclined portion  26   d . Cap portion  26   b  is provided with a shutter  32  that opens/closes a toner discharging port  33 . Shutter  32  closes toner discharge port  33  when toner bottle  26  is removed from toner supply unit  27  in order to prevent toner from dropping from toner discharge port  33  at the time when toner bottle  26  is exchanged. 
     There are a bottle stay  28  that is a supporting member and an inserting side frame  30  provided between a front frame  10   a  and a rear side toner supply unit  27  as shown in  FIG. 3 . Bottle stay  28  is made of, for example, a mold member that has a good sliding property. A toner bottle  26  passes through an inserting port  30   a  of inserting side frame  30 , slides along bottle stay  28  and installed/removed to/from toner supply unit  27 . Inserting side frame  30  has a cover  30   b  to fix the rear end of toner bottle  26  after installing toner bottle  26  to toner supply unit  27 . 
     On the bottom surface of inserting port  30   a  of inserting side frame  30 , a buffering block  34  that is a buffering member is provided as shown in  FIG. 4 . Buffering block  34  has a Mylar (Trade Mark)  34   b , that is a sliding member bonded on the upper surface of an urethane rubber made base material  34   a  that is a foaming material. Buffering block  34  is projecting from the bottom surface of inserting port  30   a . Thus, an inclined portion  26   d  and cap portion  26   b  of toner bottle  26  are brought in contact with buffering block  34  when passing inserting port  30  so as to relief the shock of being stricken to the bottom surface of inserting port  30   a.    
     Next, the operations will be described. When the image forming process starts, photosensitive drum  1  is uniformly changed by main charger  2  according to the rotation in the direction of arrow mark q and an electrostatic latent image is formed by laser exposing unit  7  according to an image signal. Thereafter, photosensitive drum  1  reaches developing unit  3  and a toner image is formed thereon. The toner image formed on photosensitive drum  1  is transferred on a sheet paper, etc. by transfer/separation charger  4 . After completing the transfer of a toner image, photosensitive drum  1  becomes ready to forming of next image after processed by cleaner  5  and electric charge eliminator  6 . Further, a sheet paper with a toner image transferred is discharged in paper discharging portion  13  in the main body after fixed by fixing unit  22 . 
     When the drop of toner density in developing unit  3  is detected while such the image forming process is carried out, toner is supplied from toner bottle  26 . Toner bottle  26  is rotated by the rotating drive of toner supply unit  27 . Toner in toner containing portion  26   a  is conveyed in the direction of toner discharging port  33  sequentially along conveying groove  26   c  to toner supply unit  27  and further, to developing unit  3 . When toner density in developing unit  3  reaches required density, toner supply unit  27  is stopped to drive. 
     When toner bottle  26  is emptied by the toner supply operation, toner bottle  26  is slid in the arrow direction r and cap portion  26   b  is taken out from toner supply unit  27 . In conjunction with this operation, shutter  32  closes toner discharging port  33 . Thereafter, toner bottle  26  is further slide in the arrow direction r in the state supported by bottle stay  28  and taken out from copying machine  10 . While being slid, toner bottle  26  is in contact with buffering block  34 . However, the toner bottle is smoothly slid without receiving a frictional resistance by buffering block  34  because Mylar  34   b  is bonded on the upper surface of buffering block  34 . 
     Further, when inclined portion  26   d  and cap portion  26   b  of toner bottle  26  reach inserting side frame  30 , the bottle cannot pass through inserting port  30   a  for the step with toner containing portion  26   a . However, inclined portion  26   d  and cap portion  26   b  of toner bottle run against elastic buffering block  34  at an inserting side frame  830 . Thus, the shock generated to toner bottle  26  when inclined portion  26   d  and cap portion  26   b  pass through inserting side frame  30  is absorbed by buffering block  34 . As a result, toner adhered around cap portion  26   b  is prevented to drop around inserting side framed  30 . Then, a new toner bottle  26  is inserted into copying machine  10  through inserting side frame  30 . A new toner bottle  26  is slid in the arrow direction s along bottle stay  28  and cap portion  26   a  is installed to toner supply unit  27 . Further, even if toner adhered around cap portion  26   d  drops on buffering block  34  when toner bottle  26  is pulled out, as Mylar  34   b  is bonded on its upper surface, it becomes easy to wipe off dropped toner. 
     According to this first embodiment, buffering block  34  is provided on the bottom surface of inserting port  30   a  of inserting side frame  30  that supports toner bottle  26 . AS a result, even if toner bottle  26  is slid along bottle stay  28  and taken out from copying machine  10 , a shock generated when inclined portion  26   d  and cap portion  26   b  run against inserting side frame  30  can be relieved by the step produced with toner containing portion  26   a . Therefore, even when toner bottle  26  is taken out by sliding along bottle stay  28  in, for example, one hand, toner adhered to cap portion  26   b  is prevented from dropping when inclined portion  26   d  and cap portion  26   b  pass through inserting side frame  30 . As a result, it is possible to take out toner bottle  26  easily and the contamination around inserting side frame  30  by dropping toner can be prevented. Furthermore, as Mylar  34   b  is bonded on the upper surface of buffering block  34 , the sliding movement of toner bottle  26  is not impaired. In addition, when toner is adhered to buffering block  34 , it can be easily wiped off. 
     Next, a second embodiment of this invention will be explained. In this second embodiment, the buffering member is in a construction differing from that in the first embodiment described above but all other elements are the same as those in the first embodiment. Therefore, in this second embodiment, the same component elements as those in the first embodiment will be assigned with the same reference numerals and the detailed explanation thereof will be omitted. 
     As shown in  FIG. 5 , in the second embodiment, an elastic plate  36  that is a buffering member is provided on the bottom surface of inserting port  30   a  of inserting side frame  30 . Elastic plate  36  has a slider  36   a  made of a mold member that is a sliding member and a coil spring  36   b  that is an elastic matter. Coil spring  36   b  supports slider  36   a  so that it is able to swing. Slider  36   a  is able to slide a toner bottle smoothly without generating friction resistance to toner bottle  26 . Slider  36   a  is inclined to become high toward bottle stay  28  side. In the free state, slider  36   a  projects higher than the bottom surface of inserting port  30   a  at the bottle stay side, while almost the same height as the bottom surface of inserting port  30   a  at the inlet port side. 
     As a result, inclined portion  26   a  and cap portion  26   b  of toner bottle  26  are supported by slider  36  that is pushed up by coil spring  36   b  when toner bottle  26  is taken out from copying machine  10 , and irrespective of a step produced between toner containing portion  26   a  to cap portion  26   b , a shock applied to toner bottle  26  when struck against the bottom surface of inserting port  30   a  is relieved. AS a result, toner adhered around cap portion  26   b  is prevented from dropping to the surrounding area of inserting side frame  30 . On the other hand, when installing toner bottle  26  into copying machine  10 , the leading end of slider  36   a  does not interfere with inclined portion  26   d  of toner bottle  26  and toner bottle  26  is able to pass through the position of elastic plate  36  smoothly. 
     According to the second embodiment, there is elastic plate  36  provided on the bottom surface of inserting port  30   a  of inserting side frame  30  that supports toner bottle  26 . As a result, likewise the first embodiment, the shock produced when inclined portion  25   d  and cap portion  26   b  run against inserting side frame  30  can be relieved. Accordingly, when exchanging toner bottle  26 , the drop of toner adhered to cap portion  26   b  can be prevented and the contamination around inserting side frame  30  can be prevented. Furthermore, as slider  36   a  is inclined, the leading end of slider  36   a  is not caught and toner bottle  26  can be inserted smoothly. 
     Next, the third embodiment of this invention will be explained. In this third embodiment, the construction of a buffering member is different from that in the first embodiment described above but all other elements are the same as those in the first embodiment. Therefore, in this third embodiment, the same structural elements as those explained in the first embodiment will be assigned with the same reference numerals and the detailed explanation thereof will be omitted. 
     In the third embodiment, elastic roller  37  that is a buffering member is provided on the bottom surface of inserting port  30   a  of inserting frame  30  as shown in  FIG. 6 . Elastic roller  37  is a sliding member and has a roller  37   a  freely rotating against a shaft  37   c  and a coil spring  37   b  that is an elastic matter. Coil spring  37   b  supports shaft  37   c  of roller  37   a  so as to swing. Since roller  37   a  is able to rotate freely, it is possible to smoothly slide a toner bottle without causing frictional resistance. In the free state, the upper portion roller  37   a  is projecting from the bottom surface of inserting port  30   a.    
     Thus, when toner bottle  26  is taken out from copying machine  10 , inclined portion  26   d  and cap portion  26   b  of toner bottle  26  are supported by roller  37   a  that is pushed up by coil spring  37 . Therefore, irrespective of a step extending to cap portion  26   b  from toner containing portion  26   a , a shock produced when stricken against the bottom surface of inserting port  30   a  is relieved. As a result, toner adhered around cap portion  26   b  is prevented from dropping around inserting side frame  30 . Further, as roller  37   a  freely rotates according to the sliding direction of toner bottle  26 , when inserting toner bottle  27  into copying machine  10 , roller  37   a  rotates in the inserting direction so as to pass toner bottle smoothly. 
     According to this third embodiment, there is elastic roller  37  is provided on the bottom surface of inserting port  30   a  of inserting side frame  39  that supports toner bottle  26 . By this construction, likewise the first embodiment, a shock produced when inclined portion  26   d  and cap portion  26  run against inserting side frame  30  can be relieved. Accordingly, toner adhered to cap portion  26   b  is prevented from dropping when toner bottle  26  is exchanged and the contamination around inserting side frame  30  can be prevented. Furthermore, since roller  37   a  freely rotates along the sliding direction of toner bottle  26 , roller  37   a  is able to insert toner bottle  26  smoothly without becoming a resistance. 
     Next, a fourth embodiment of this invention will be explained. In this fourth embodiment, a buffering member is also provided at a toner supply mechanism in the first embodiment and all other elements are the same as the first embodiment. Therefore, in this fourth embodiment, the construction elements as those in the first embodiment will be assigned with the same reference numerals as those in the first embodiment and the detailed explanation thereof will be omitted. 
     In the fourth embodiment, a second buffering block  38  that is a second buffering member is provided on the bottom surface of cap guide  27   a  of toner supply unit  27  as shown in  FIG. 7 . Second buffering block  38  has, for example, Mylar  38   b  bonded on the upper surface of urethane rubber made base material  38   a  likewise buffering block  34 . When toner bottle  26  is inserted in toner supply unit  27 , a step β is produced between cap guide  27   a  and cap portion  26   b  at the inserting side portion of cap guide  27   a  as shown in  FIG. 8 . Therefore, when cap portion  26   b  is taken out from cap guide  27   a  when exchanging toner bottle  26 , cap portion  26   b  drops for the step β. However, cap portion  26   b  is brought in contact with second elastic buffering block  38  and a shock resulting from dropping is absorbed. Thus, toner adhered around cap portion  26   b  is prevented from dropping to the periphery of cap guide  27   a.    
     According to this fourth embodiment, it is possible to prevent the contamination around inserting side frame  30  by toner dropping by buffering block  34  when exchanging toner bottle  26 . Further, the contamination around cap guide  27   a  caused by toner dropping can be prevented by second buffering block  38 . 
     Further, in this fourth embodiment, second buffering block  38  is used as a second buffering member but not restricting to this, any elastic member in the similar shape as an elastic plate to push up the slider in the second embodiment or elastic roller  37  to push up shaft  37   c  of roller  37   a  with coil spring  37   b  can be used as a second buffering member. 
     Next, a fifth embodiment of this invention will be explained. In this fifth embodiment, a detecting member to detect the swing of a buffering member is provided in the second embodiment and all other elements are the same as those in the second embodiment. Therefore, in this fifth embodiment, the same structural elements explained in the second embodiment will be assigned with the same reference numerals and the detailed explanation thereof will be omitted. 
     In the fifth embodiment, a micro-sensor  40  that is a detecting member is provided below slider  36   a  of elastic plate  36  as shown in  FIG. 9 . When there is toner bottle  26  at the position of inserting port  30   a , this micro-sensor  40  is pushed down to the lower surface of slider  36   a  that is pushed by toner bottle  26  and is turned ON. Where there is no toner bottle  26  at the position of inserting port  30   a , slider  36   a  is pushed up by coil spring  36   b , micros-sensor  40  is turned OFF. When, for example, the front cover is closed although micro-sensor  40  is in the OFF state without detecting toner bottle  26  at the time when exchanging toner bottle  26 , a warning is shown on a panel indicating that no toner bottle  26  is inserted. On the other hand, when micro-sensor  40  is pushed by slider  36   a  and turned ON when exchanging toner bottle  26  and it is detected that toner bottle  26  is inserted, toner supply unit  27  becomes rotatable and toner can be supplied. Thus, it is prevented that toner supply unit  27  is driven by forgetting to insert new toner bottle  26  into copying machine  10 . 
     According to this fifth embodiment, it is possible to prevent forgetting to insert new toner bottle  26  into copying machine  10  when exchanging toner bottle  26 . 
     Further, in this fifth embodiment, a micro-switch which is switched by contact with toner bottle  26  is used as a detecting member but not restricting to this micro-switch, for example, a transmission photo-sensor  41  that is switched with the swing of shaft  37   c  of elastic roller  37  may be used as a detecting member as in the sixth embodiment shown in  FIG. 10 . 
     Next, a seventh embodiment of this invention will be explained. In this seventh embodiment, a buffering member and a detecting member to detect a toner supply container are provided at the toner supply mechanism side in the fifth embodiment and all other component elements are same as those in the fifth embodiment. Therefore, in this seventh embodiment, the same structural components as those explained in the fifth embodiment will be assigned with the same reference numerals and the detailed explanation thereof will be omitted. 
     In the even embodiment, a second elastic plate  42  that is a second buffering member is provided on the bottom surface of cap guide  27   a  of toner supply unit  27  as shown in  FIG. 11 . Further, under second slider  42   a  of second elastic plate  42 , a micro-sensor  43  that is a second detecting member is provided. Thus, the shock by the drop of cap portion  26   b  produced when cap portion  26   b  is taken out from cap guide  27   a  is absorbed by elastic plate  42 . 
     Further, normally when cap portion  26   b  of toner bottle  26  is properly attached to toner supply unit  27 , second slider  42   a  is pushed up by coil spring  42   b  and second micro-sensor  43  is turned OFF as shown by the solid line in  FIG. 11 . Therefore, when second micro-sensor is OFF, for example, when the front cover is closed after completing the exchanging operation of toner bottle  26 , a controller of copying machine  10  recognizes that new toner bottle  26  is properly attached to toner supply unit  27 . 
     On the other hand, if second micro-sensor  43  is ON when the front cover is closed after completing the exchanging operation of toner bottle  26 , cap portion  26   b  may possibly be shifted from bottle guide  27   a  and push down second slider  42   a  as shown by the dotted line shown in  FIG. 11 . In such the case, a warning is displayed on the panel indicating that cap portion  26   b  is not surely attached to toner supply unit. Thus, it is prevented to drive toner supply unit  27  without cap portion  26   b  properly inserted when exchanging toner bottle  26 . 
     According to this seventh embodiment, toner supply unit is prevented to be driven without new toner bottle  26  inserted properly. 
     Further, the application of this invention is not restricted to the above embodiments but can be modified variously within the scope of the invention. For example, the number of toner supply mechanisms equipped to an image forming apparatus is optional depending on the number of toners used in the image forming. Further, the construction of buffering member and others are not restricted provided that shock generated in a toner supply container is absorbed while a toner supply container is slid and moved. 
     Further, a toner supply container contains not only toner but may contain developing agent mixed with toner and a small amount of carrier. In recent years, there is available a so-called overflow type developing device that discharges amount of developer increased to a certain level and overflow while a new toner is supplied into a developer container according to density of developer. In the case of this overflow type-developing device, when not only new toner but also new carrier is supplied sequentially, the maintenance-free system requiring no exchange of developer by the maintenance can be realized. A toner supply container containing toner with a small amount of carrier mixed can be used for the supply of developer to such the overflow-type developing device.