Patent Publication Number: US-9409420-B2

Title: Recirculate and filter air to form air barrier in image forming apparatus

Description:
This application is a continuation of U.S. patent application Ser. No. 14/371,344, filed Jul. 9, 2014, currently allowed, which is a 371 of International Application PCT/US2012/031700, filed on Mar. 30, 2012, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Image forming apparatuses may include fluid applicator units to eject fluid such as ink in the form of drops on substrates. The image forming apparatuses may form an air barrier to reduce an amount of aerosol, particulates, and the like, from being deposited on the substrate, fluid applicator unit, and/or other components of the image forming apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting examples are described in the following description, read with reference to the figures attached hereto and do not limit the scope of the claims. Dimensions of components and features illustrated in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. Referring to the attached figures: 
         FIG. 1  is a block diagram of an image forming apparatus according to an example. 
         FIG. 2A  is a schematic side view of an image forming apparatus in a print mode according to an example. 
         FIG. 2B  is a schematic side view of an image forming apparatus in a maintenance mode according to an example. 
         FIG. 3  is a top view of a substrate receiving member of the image forming apparatus of  FIG. 2B  according to an example. 
         FIG. 4  is a flowchart illustrating a method of recirculating air in an image forming apparatus according to an example. 
         FIG. 5  is a block diagram illustrating a computing device such as an image forming apparatus including a processor and a non-transitory, computer-readable storage medium to store instructions to operate the computing device to recirculate air according to an example. 
     
    
    
     DETAILED DESCRIPTION 
     Image forming apparatuses may include fluid applicator units to eject fluid such as ink in the form of drops on substrates. The image forming apparatuses may form an air barrier to reduce an amount of aerosols, particulates, and the like, from being deposited on the substrate, fluid applicator unit, and/or other components of the image forming apparatuses. The image forming apparatuses may also periodically perform maintenance procedures to maintain flow paths within the fluid applicator units in order to properly eject drops there from. That is, in a maintenance mode, the fluid applicator unit may periodically perform spitting procedures in which fluid is ejected from the fluid applicator unit in the form of drops there from. The drops ejected from the fluid application units, however, may form aerosol which, if not properly removed, may contaminate the substrate and/or components of the image forming apparatuses. Further, aerosol can cloud optical sensors causing premature failure, increase friction in rotating members, deposit on media path surfaces increasing friction and potentially causing a leak out of the image forming apparatus dirtying both the interior and surroundings. In addition, the combination of aerosol with other particulates can interact to increase these issues by forming sticky, globular masses. Further, particulates such as dust, paper debris, and the like, may also contaminate the substrate. Thus, the aerosol and/or particulates may cause image defects, component malfunctions, and/or reduce the lifespan of the image forming apparatuses. 
     In examples, an image forming apparatus includes, amongst other things, a substrate receiving member, a fluid applicator unit, and an air recirculator assembly. The fluid applicator unit may selectively eject a first set of drops to the substrate received by the substrate receiving member in a print mode and a second set of drops in a maintenance mode. The air recirculater assembly may direct air to form an air barrier across the print zone to redirect at least one of aerosol and particulates from crossing through the air barrier and onto the substrate, to filter the at least one of the aerosol and particulates to form filtered air, and to form the air barrier with the filtered air. Accordingly, adequate redirection and extraction of aerosol and/or particulates may be effectively performed. Additionally, the substrate may be prevented from contacting a surface of the fluid applicator unit. Thus, image forming defects, component malfunctions, and the reduction in the lifespan of the image forming apparatus may be reduced. 
       FIG. 1  is block diagram of an image forming apparatus according to an example. Referring to  FIG. 1 , in some examples, an image forming apparatus  100  includes a substrate receiving member  12 , a fluid applicator unit  14 , and an air recirculater assembly  16 . The substrate receiving member  12  may selectively receive a substrate. That is, the substrate may be transported along a substrate transport path to be placed on the substrate receiving member  12 . The substrate may include media such as paper, vinyl, plastic, cloth, and the like. In some examples, different-sized substrate may be received by the substrate receiving member  12 . The substrate receiving member  12  may be a platen, and the like. 
     Referring to  FIG. 1 , in some examples, the fluid applicator unit  14  may selectively eject a first set of drops to the substrate disposed on the substrate receiving member  12  in a print mode. The fluid applicator unit  14  may also selectively eject a second set of drops in a maintenance mode. That is, the print mode is a mode in which a first set of drops of fluid are ejected by the fluid applicator unit  14  onto the substrate. For example, the first set of drops may form images on the substrate. Alternatively, the maintenance mode is a mode in which a second set of drops of fluid are ejected by the fluid applicator unit  14  to maintain flow paths in the fluid applicator unit  12  for proper ejection of subsequent first set of drops there from. 
     In some examples, the fluid applicator unit  14  may include at least one inkjet print head to eject ink in the form of drops. For example, the fluid applicator unit  14  may be a page wide inkjet print head array that includes a plurality of inkjet print heads that extend across a width of a substrate transport path. That is, the plurality of inkjet print heads may extend across a width of a substrate passing into a print zone and disposed on the substrate receiving member  12 . The fluid applicator unit  14  and the substrate receiving member  12  may form a print zone there between. The air recirculater assembly  16  may direct air to form an air barrier across the print zone to redirect at least one of aerosol and particulates from crossing through the air barrier and onto the substrate. The air recirculater assembly  16  may also filter the at least one of the aerosol and particulates to form filtered air. The air recirculater assembly  16  may also form the air barrier with the filtered air. Additionally, the substrate may be prevented from contacting a surface of the fluid applicator unit  14 . 
       FIG. 2A  is a schematic side view of an image forming apparatus in a print mode according to an example.  FIG. 2B  is a schematic side view of an image forming apparatus in a maintenance mode according to an example. Referring to  FIGS. 2A and 2B , in some examples, an image forming apparatus  200  may include a substrate receiving member  12 , a fluid applicator unit  14 , and an air recirculater assembly  16  as previously disclosed with respect to the image forming apparatus  100  of  FIG. 1 . In some examples, the image forming apparatus  200  may also include a service unit  25 . The service unit  25  may receive at least one of the second set of drops  21   b  and the at least one of the aerosol  21   c  and particulates  21   d . In some examples, the service unit  25  may include a maintenance member  25   a  to collect at least one of the second set of drops  21   b  and the at least one of the aerosol  21   c  and particulates  21   d . For example, the maintenance member  25   a  may be in a form of a spit roller, and the like. 
     Referring to  FIGS. 2A and 2B , in some examples, in the maintenance mode, the substrate m does not cover the at least one maintenance opening  23   b  (e.g., the substrate m moved from or not yet received on the substrate receiving area  22 ) and the second set of drops  21   b  ejected from the fluid applicator unit  14  pass through the maintenance opening  23   b  and onto the maintenance member  25   a  as illustrated in  FIG. 2B . In some examples, the air recirculater assembly  16  may include a filter unit  29  and an airflow unit  27 ,  28   a  and  28   b . The filter unit  29  may filter the at least one of the aerosol  21   c  and particulates  21   d  from the air. That is, the filter unit  29  is able to remove a large percentage of aerosol and particulates before the air flow moves to the first duct member  28   a . In some examples, the filter unit  29  may include an aerosol filter, and the like. For example, the filter unit  29  may include at least one of needlefelt, polyester, open cell, closed cell, pleated, charged, and the like. 
     Referring to  FIGS. 2A and 2B , in some examples, the airflow unit  27 ,  28   a  and  28   b  may direct the air to pass through the filter unit  29  to form the filtered air and direct the filtered air to form the air barrier  24   a . In some examples, the air may be directed by the fan  27  in multiple paths to subsequently meet to form the air barrier  24   a . The airflow unit  27 ,  28   a  and  28   b  may include a fan  27 , a first duct member  28   a  and a second duct member  28   b . The fan  27  may suck the air forming the air barrier  24   a  including the at least one of the aerosol  21   c  and particulates  21   d  through the filter unit  29  to form the filtered air. The fan  27  may also push the filtered air across the print zone  24  to form the air barrier  24   a . The first duct member  28   a  may be disposed between the fan  27  and the print zone  24 . The first duct member  28   a  may form a first channel to guide the filtered air from the fan  27  to the print zone  24 . The second duct member  28   b  may be disposed between the fan  27  and the substrate receiving member  12  to form a second channel to guide the air to the fan  27 . In some examples, the filter unit  29  may be disposed in the second duct member  28   b.    
       FIG. 3  is a top view of a substrate receiving member of the image forming apparatus of  FIG. 2B  according to an example. Referring to  FIGS. 2B and 3 , in some examples, a substrate receiving member  12  may also include a substrate receiving area  22  to receive the substrate m and at least one recirculation opening  23   c  for the air to pass through the substrate receiving member  12  to the second duct member  28   b . For example, the recirculation opening  23   c  may allow a continuous path of air to and from the fan  27  to filter the air to remove the aerosol and/or particulates there from and for the filtered air to form the air barrier  24   a . Recirculation of the air flow provides additional filtering of the air as it makes air flow in the system closed-loop to a large extent. Even if the aerosol makes it through the filter unit  29  during an initial pass, it is likely that it will be impacted onto maintenance member  25 A. In some examples, this process will repeat continuously as long as the fan  27  is running. In some examples, the substrate receiving area  22  may also include a plurality of positioning holes  23   a  and at least one maintenance hole  23   b . The plurality of positioning holes  23   a  may enable the fan  27  to suck the air to selectively hold the substrate m against the substrate receiving area  22  in the print mode. 
     Referring to  FIGS. 2A, 2B and 3 , in some examples, the at least one maintenance hole  23   b  may allow the second set of drops  21   b  selectively ejected from the fluid applicator unit  14  to pass through the substrate receiving member  12  to the maintenance member  25   a  of the service unit  25 . In some examples, the substrate m may uncover the at least one maintenance hole  23   b  to enable the second set of drops  21   b  to be received by the service unit  25  and/or contact the maintenance member  25   a . That is, the second set of drops  21   b  may be selectively ejected in the maintenance mode before the substrate m is received by or after the substrate m is moved from the substrate receiving area  22  of the substrate receiving member  12 . 
       FIG. 4  is a flowchart illustrating a method of recirculating air in an image forming apparatus according to an example. Referring to  FIG. 4 , in block S 410 , a substrate is selectively transported to and from a substrate receiving member. In block S 412 , air is directed by an airflow unit of an air recirculater assembly to form an air barrier across a print zone formed between a fluid applicator unit and the substrate receiving member to redirect at least one of aerosol and particulates from crossing through the air barrier and onto the substrate. For example, filtered air may be pushed across the print zone by a fan to form the air barrier. In block S 414 , a first set of drops is selectively ejected by the fluid applicator unit through the air barrier to the substrate received by the substrate receiving member in a print mode. 
     Referring to  FIG. 4 , in block S 416 , the at least one of the aerosol and particulates is filtered from the air by a filter unit of the air recirculater assembly to form filtered air. For example, the air forming the air barrier including the at least one of the aerosol and particulates may be sucked through the filter unit by a fan to form the filtered air. That is, the air forming the air barrier may be passed through at least one recirculation opening disposed through the substrate receiving member and through the filter unit. In some examples, the filtered air may be used by the airflow unit to form the air barrier. In block S 418 , a second set of drops is selectively ejected by the fluid applicator unit in a maintenance mode to a service unit. For example, the second set of drops ejected from the fluid applicator unit may be ejected through at least one maintenance hole disposed through the substrate receiving member to a maintenance member of the service unit. In some examples, operations S 410  to S 418  may be continuously repeated, for example, while the image forming apparatus is turned on, in a printing mode, and/or in a maintenance mode. 
       FIG. 5  is a block diagram illustrating a computing device such as an image forming apparatus including a processor and a non-transitory, computer-readable storage medium to store instructions to operate the computing device to recirculate air according to an example. Referring to  FIG. 5 , in some examples, the non-transitory, computer-readable storage medium  55  may be included in a computing device  50  such as an image forming apparatus  100  and  200 . In some examples, the non-transitory, computer-readable storage medium  55  may be implemented in whole or in part as computer-implemented instructions stored in the image forming apparatus  100  and  200  locally or remotely, for example, in a server or a host computing device considered herein to be part of the image forming apparatus  100  and  200 . 
     Referring to  FIG. 5 , in some examples, the non-transitory, computer-readable storage medium  55  may correspond to a storage device that stores computer-implemented instructions, such as programming code, and the like. For example, the non-transitory, computer-readable storage medium  55  may include a non-volatile memory, a volatile memory, and/or a storage device. Examples of non-volatile memory include, but are not limited to, electrically erasable programmable read only memory (EEPROM) and read only memory (ROM). Examples of volatile memory include, but are not limited to, static random access memory (SRAM), and dynamic random access memory (DRAM). 
     Referring to  FIG. 5 , examples of storage devices include, but are not limited to, hard disk drives, compact disc drives, digital versatile disc drives, optical drives, and flash memory devices. In some examples, the non-transitory, computer-readable storage medium  55  may even be paper or another suitable medium upon which the instructions  57  are printed, as the instructions  57  can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a single manner, if necessary, and then stored therein. A processor  59  generally retrieves and executes the instructions  57  stored in the non-transitory, computer-readable storage medium  55 , for example, to operate a computing device  50  such as an image forming apparatus  100  and  200  to recirculate air in accordance with an example. In an example, the non-transitory, computer-readable storage medium  55  can be accessed by the processor  59 . 
     It is to be understood that the flowchart of  FIG. 4  illustrates architecture, functionality, and/or operation of examples of the present disclosure. If embodied in software, each block may represent a module, segment, or portion of code that includes one or more executable instructions to implement the specified logical function(s). If embodied in hardware, each block may represent a circuit or a number of interconnected circuits to implement the specified logical function(s). Although the flowchart of  FIG. 4  illustrates a specific order of execution, the order of execution may differ from that which is depicted. For example, the order of execution of two or more blocks may be scrambled relative to the order illustrated. Also, two or more blocks illustrated in succession in  FIG. 4  may be executed concurrently or with partial concurrence. All such variations are within the scope of the present disclosure. 
     The present disclosure has been described using non-limiting detailed descriptions of examples thereof that are not intended to limit the scope of the general inventive concept. It should be understood that features and/or operations described with respect to one example may be used with other examples and that not all examples have all of the features and/or operations illustrated in a particular figure or described with respect to one of the examples. Variations of examples described will occur to persons of the art. Furthermore, the terms “comprise,” “include,” “have” and their conjugates, shall mean, when used in the disclosure and/or claims, “including but not necessarily limited to.” 
     It is noted that some of the above described examples may include structure, acts or details of structures and acts that may not be essential to the general inventive concept and which are described for illustrative purposes. Structure and acts described herein are replaceable by equivalents, which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the general inventive concept is limited only by the elements and limitations as used in the claims.