Patent Publication Number: US-6711366-B2

Title: Residual toner management in an electrophotographic device

Description:
BACKGROUND 
     It is generally known that electrophotographic devices (e.g., printers, copiers utilize toner to generate text and/or images on a print medium (e.g., paper, transparency media). In this regard, a toner cartridge typically stores the toner and an optical photoreceptor (“OPR”) is utilized to collect toner from the toner cartridge. As described in greater detail below, In a class of electrophotographic devices the toner is transferred from the OPR to an intermediate transfer device (“ITD”) and then transferred to the print medium. 
     In one class of electrophotographic device, an ITD, such as, an intermediate transfer cylinder (“ITC”), an Intermediate transfer belt (“ITB”) or the like, is utilized to collect toner from the OPR. Following the transfer to the OPR, a scraping device is generally utilized to remove any remaining toner from the OPR. This “residual toner” generally accumulates on the leading edge of the scraping device. As additional residual toner is accumulated on the leading edge of the scraping device, this newly collected residual toner may push the previously collected residual toner into a slot. The slot generally serves as an opening for a receptacle (e.g., hopper, container, bin) where the residual toner is stored. The receptacle is typically about as wide as the toner cartridge. 
     Furthermore, the ITD may be configured to apply the toner to the print medium. While a majority of the toner may be transferred to the print medium, some toner may remain on the ITO. To substantially prevent the remaining toner from adversely affecting the image quality of subsequent printed content (e.g., text, images), a scraping or brushing mechanism is typically employed to essentially clean the ITD following the transfer of the toner to the print medium. 
     This remaining (i.e., residual) toner is typically deposited in a bin. The bin is typically either a user serviceable component or of sufficient capacity to collect residual toner for the expected life of the electrophotographic device. In this regard, a user serviceable bin may represent yet another component the user may have to purchase and/or attend to. This may increase user frustration particularly if the bin servicing procedure is messy. Alternatively, if the bin is large enough to collect residual toner over the expected life of the electrophotographic device, the size of the electrophotographic device may be inconveniently large. 
     SUMMARY 
     In accordance with an embodiment, the invention pertains to a component for an electrophotographic device having an intermediate transfer device. This component includes a hopper configured for association with a toner cartridge. The hopper is configured to store residual toner collected from the intermediate transfer device. The hopper includes an opening configured to receive the residual toner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention are illustrated by way of example and not limitation in the accompanying figures in which like reference numerals refer to like elements, and wherein: 
     FIG. 1 is a simplified perspective view of an electrophotographic printing device according to an embodiment of the invention; 
     FIGS. 2A-2C are cross sectional views of toner cartridges according to various embodiments of the invention; 
     FIGS. 3A-3E are illustrations of various views of a shutter according to an embodiment of the invention; 
     FIG. 4 is a simplified perspective view of an electrophotographic printing device according to another embodiment of the invention; and 
     FIG. 5 is a simplified perspective view of an electrophotographic printing device according to yet another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     For simplicity and illustrative purposes, principles of the invention are described by referring mainly to embodiments thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent however, to one of ordinary skill in the art, that the invention may be practiced without limitation to these specific details. In other instances, well known methods and structures have not been described in detail so as not to unnecessarily obscure the invention. In addition, although FIG. 1 depicts four toner cartridges, it is to be understood that the invention is not limited to four toner cartridges, but rather, the invention may include any reasonable number of toner cartridges. In one respect, the number of toner cartridges may correspond to the number of toner colors within the electrophotographic printing device. Accordingly, the four toner cartridges depicted in FIG. 1 are for illustrative purposes only and thus is not meant to limit the invention in any respect. 
     FIG. 1 is a simplified perspective view of an electrophotographic printing (“EP”) device  100  according to an embodiment of the invention. The EP device  100  includes an intermediate transfer belt (ITB)  102 , toner cartridges  104 ,  106 ,  108 ,  110 , paper path  120 , scraper  122 , catch  124 , auger  126  and manifold  128 . The cross sectional views of several toner cartridges are shown in FIGS. 2A-2C. Additionally, each toner cartridge  104 ,  106 ,  108 ,  110  includes a respective optical photoreceptor (OPR)  112 ,  114 ,  116 ,  118  and the manifold  128  includes chutes  134 ,  136 ,  138 ,  140 . Each chute  134 ,  1336 ,  138 ,  140  is configured to attach to an opening (see FIGS. 2A-2C) in a respective toner cartridge  104 ,  106 ,  108 ,  110 . 
     The EP device  100  may be configured to print content (e.g., text, image) on to paper or other such print media. For example, the ITB  102  is driven by a motor (not shown) in direction A. As an area of the ITB  102  moves past the toner cartridge  104 , a portion of print content may be transferred from the OPR  112  to the ITB  102  in a manner similar to known EP devices. As this area of the ITB  102  moves past successive toner cartridges  106 ,  108 ,  110 , a remaining portion of the print content may be transferred from the OPR  114 ,  116 ,  118  as appropriate. In this manner, the print content may be transferred to the ITB  102 . The print content may subsequently be transferred to the print media (not shown) as the print media travels through the paper path  120 . 
     Following the transfer of the content to the print media, substantially all of the remaining toner (i.e., residual toner) may be removed from the ITB  102  by the scraper  122  or various other cleaning devices (e,g., a brush). The catch  124  Is positioned to catch the residual toner as it falls off the scraper  122  and an end of the catch  124  is configured for attachment to the manifold  128 . The auger  126  may be a helical wire, positioned at or near the bottom of the inside of the catch  124 . The auger  126  may be rotated by a motor (not shown) to convey the residual toner towards the manifold  128 . Attentively, the auger  126  may be a screw and in various other embodiments, the auger  126  may be replaced with a variety of residual toner conveyance devices (e.g., a belt, air flow, vibrating a downward sloping surface etc,). 
     Residual toner Is conveyed by the auger  126  towards the manifold  128  and is deposited within the manifold  128 . A conveyer belt  130  or other conveyance device may be positioned within the manifold  128  and configured to move residual toner. For example, the conveyer belt  130  may be driven by a motor (not shown) connected to a drive wheel  132 . The drive wheel  132  is rotated in direction B and thus, the conveyer belt  130  is driven about within the manifold  128 . As the conveyer belt  130  moves within the manifold  128 , it picks up the residual toner deposited by the auger  126 . The conveyer belt  130  moves the residual toner within the manifold  128  and, as the residual toner passes over the chutes  134 ,  136 ,  138 ,  140 , residual toner may fall down the chutes  134 ,  136 ,  138 ,  140 . For example, as residual toner passes over the chute  134 , some portion of the residual toner may fall down the chute  134  and through an opening  220  (shown in FIG. 2A) and into a hopper  210  (shown in FIG. 2A) associated with the toner cartridge  104 . In operation, if a hopper  210  (see FIGS. 2A-2C) becomes full, the respective chute  134 ,  136 ,  138 ,  140  may fill to a point in which little or no additional residual toner may accumulate. At which point the conveyer belt  130  may continue to move the residual toner within the manifold  128  until the residual toner passes over a chute  134 ,  136 ,  138 ,  140  and/or its respective hopper  210  (see FIGS. 2A-2C) that has additional capacity to receive residual toner. 
     FIGS. 2A-2C are cross sectional views of the toner cartridge  104  according to various embodiments of the invention. As shown in FIG. 1, the toner cartridge  104  is a component of the EP device  100 . Alternatively, the toner cartridge  104  may be configured to be implemented in any reasonably suitable EP device. As shown in FIG. 2A, the toner cartridge  104  includes a hopper  210 . The volume occupied by the hopper  210  may be formed by essentially replacing some portion of the volume of a conventional toner cartridge. In this manner, the toner cartridge  104  having the hopper  210  may have essentially the same dimensions as a conventional toner cartridge. 
     Additionally, the toner cartridge  104  includes an opening  220  configured to mate with a chute  134 ,  136 ,  138 ,  140  when the toner cartridge  104  is installed in a suitable EP device, such as EP devices  100  (FIG.  1 ),  400  (FIG. 4) and  500  (FIG.  6 ). Furthermore, the toner cartridge  104  includes a shutter  230  or other closure device configured to substantially seal residual toner within the hopper  210 . The operation of the shutter  230  is shown in FIGS. 3A-3E. However, in general, the shutter  230  is configured to open as the toner cartridge  104  is Installed in the EP device  100 ,  400  or  500  and dose as the toner cartridge  104  Is removed. 
     The toner cartridge  104  further includes a receptacle  240  configured to store residual toner collected from the OPR  112 . 
     FIG. 2B is a cross sectional view of the toner cartridge  104  according to another embodiment of the invention. The toner cartridge  104  of this embodiment is similar to the toner cartridge  104  described hereinabove and thus only those features which are reasonably necessary for a complete understanding of this embodiment are described hereinbelow. A difference from the toner cartridge  104  of FIG. 2A is that the volume of the hopper  210  is substantially added to the volume of a conventional toner cartridge. 
     FIG. 2C is a cross sectional view of the toner cartridge  104  according to another embodiment of the invention. The toner cartridge  104  of this embodiment is similar to the toner cartridge  104  described in FIG.  2 B and thus only those features which are reasonably necessary for a complete understanding of this embodiment are described hereinbelow. A difference from the toner cartridge  104  of FIG. 2B is that the hopper  210  of this embodiment is configured to be added to an existing toner cartridge. For example, the hopper  210  may be initially constructed as a distinct device. In this manner, during or subsequent to construction, the hopper  210  may be fastened to the toner cartridge  104  in any reasonably suitable fastening manner (e.g., adhesive, mating connectors, mechanical fasteners). 
     FIGS. 3A-3E are illustrations of various views of the shutter  230  according to an embodiment of the invention. As shown in FIG. 3A, the toner cartridge  104  includes the shutter  230 . The shutter  230  is depicted in a closed position. In this closed position, the shutter  230  is configured to substantially prevent residual toner, which may be present in the hopper  210 , from spilling out of the opening  220  (opening  220  shown in FIG.  3 B). 
     FIG. 3B is an illustration of the shutter  230  in an open position. In this open position, the shutter  230  is configured to allow residual toner to enter the hopper  210  through the opening  220 . 
     FIG. 3C is an illustration of the shutter  230  in the closed position from within the hopper  210 . As shown by this view, a spring  310  is configured to provide sufficient force to substantially prevent the casual opening of the shutter  230 . 
     FIG. 3D is an illustration of the shutter  230  in the open position from within the hopper  210 . 
     FIG. 3E is an illustration of the shutter  230 . As shown in FIG. 3E, the shutter  230  includes a lip  320 . The lip  320  may be configured to provide a bearing surface with which the shutter  230  may be opened as the toner cartridge  104  is installed within the EP device  100 ,  400  or  500 . Additionally, the shutter  230  includes holes  330  and  340 . The hole  330  may be configured to accept one end of the spring  310 . The hole  340  may be configured for attachment to a post (not shown) on the toner cartridge  104 . In this manner, the hole  340  may provide a pivot point for the shutter  230 . 
     It is to be understood that the shutter  230  depicted above is for illustrative purposes only and not meant to limit the scope of the invention. In this regard, any reasonable device operable to substantially seal residual toner within the hopper  210  when the toner cartridge  104  is removed from the EP device  100 ,  400  or  500  and operable to allow residual toner to enter the hopper  210  when the toner cartridge  104  is installed in the EP device  100 ,  400  or  500  may be substituted for the shutter  230 . 
     FIG. 4 is a simplified perspective view of an EP device  400  according to another embodiment of the invention. The EP device  400  of this embodiment is similar to the EP device  100  described hereinabove and thus only those features which are reasonably necessary for a complete understanding of this embodiment are described hereinbelow. Two differences from the EP device  100  are that the EP device  400  is configured in a relatively upright position relative to the EP device  100  and that a single chute  402  may be configured to convey residual toner to the toner cartridges  104 ,  106 ,  108 ,  110 . 
     With regard to the chute  402 , in operation, a conveyer belt  404  may be configured to transport the residual toner up a manifold  406  and deposit the residual toner at or near the top of the chute  402 . As the residual toner falls down the chute  402 , some portion of the residual toner may be deflected by an indent  408 . The indent  408  is configured to direct the falling residual toner into the opening  220  (not shown in FIG. 4) in the toner cartridge  104 . In an embodiment, the indent  408  may be configured such that a majority of the falling residual toner is directed through the opening  220  of the toner cartridge  104  and into the hopper  210  (not shown in FIG.  4 ). At such time that the hopper  210  becomes full, residual toner may block the opening  220  to the extent that little or no additional residual toner may enter the hopper  210 . 
     Accordingly, residual toner may fill the indent  408  and allow substantially all of any additional residual toner to continue falling down the chute  402 . As the residual toner continues to fall down the chute  402 , some portion of the residual toner may be deflected by an indent  410 . In a manner similar to the indent  408 , the indent  410  is configured to direct at least some of the falling residual toner into the hopper  210  associated with the toner cartridge  106 . Additionally, an indent  412  may function similarly to direct falling toner into the hopper  210  associated with the toner cartridge  108 . 
     If the volume of residual toner exceeds the capacity of the hoppers  210  associated with the toner cartridges  104 ,  106 ,  108 , residual toner may continue to fall down the chute  402  until it is directed into the hopper  210  associated with the toner cartridge  110 . In this regard, the combined capacity of the hoppers associated with the toner cartridges  104 - 110  may be designed to hold at least as much residual toner as may reasonably be expected to be generated during the life of the toner cartridges  104 ,  106 ,  108 ,  110 . The actual volume of the hopper  210  is determined based upon system design and the efficiency of toner transfer to the print medium. 
     In general, the volume of the hopper  210  may depend upon the following factors: system application, amount of toner per toner cartridge, transfer efficiency of toner from the ITB  102  to the print medium, optimization of the system, type of print job being performed, and the like. In one respect the volume of each hopper  210  may be designed to hold at least as much residual toner as may reasonably be expected to be generated based on the amount of toner originally placed in the respective toner cartridge  104 ,  106 ,  108 ,  110 . Furthermore, in the event a user replaces a toner cartridge  104 ,  106 ,  108 ,  110  (e.g., toner is exhausted, toner cartridge malfunction, etc.), installation of a replacement for the toner cartridge  104 ,  106 ,  108 ,  110 , may add to available hopper capacity. 
     FIG. 5 is a simplified perspective view of an EP device  500  according to yet another embodiment of the invention. The EP device  500  of this embodiment is similar to the EP device  100  described hereinabove and thus only those features which are reasonably necessary for a complete understanding of this embodiment are described hereinbelow. One difference from the EP device  100  is that the EP device  500  is configured with an intermediate transfer drum (“ITD”)  502 . In a manner similar to the ITB  102 , the ITD  510  may be utilized to collect toner from the one or more toner cartridges  104 ,  106 ,  108 ,  110  and transfer the toner to print media (not shown). 
     What has been described and illustrated herein are embodiments of the invention along with some of their variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated.