Patent Publication Number: US-2016246242-A1

Title: Printhead including an assembly for cleaning a lens and a displaceable light-emitting diode assembly and methods thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional patent application under 35 U.S.C. 121 of application Ser. No. 14/571,849, filed on Dec. 16, 2014, which application is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a displaceable assembly for a printbar including LEDs for the printbar and methods thereof. 
     BACKGROUND 
     For a printbar including light-emitting diodes (LEDs), dust and debris can coat and obscure a lens used to focus light from the LEDs during operation of the printhead. In particular, during operation of the printhead, media passing through the printhead can generate particulate which coats the lens. Coating the lens undesirably decreases the intensity of the light from the LEDs, adversely affecting printing quality. Known methods of cleaning a lens for an LED printbar entail removal of components to reach and clean the lens, which can be time intensive and may require expertise not available to most users of a device including the printbar. 
     SUMMARY 
     According to aspects illustrated herein, there is provided a printhead for a device capable of printing, including: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs on the housing and extending in a first transverse direction, and at least one lens parallel to the plurality of LEDs in the first traverse direction and arranged to focus light from the LEDs; and a lens cleaning assembly engaged with the frame and including an arm portion extending across the frame in the first traverse direction and a cleaner portion including a cleaning element. The lens cleaning assembly is displaceable, with respect to the frame, in the first transverse direction to slide the cleaning element across the at least one lens. 
     According to aspects illustrated herein, there is provided a printhead for a device capable of printing, including: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs one the housing and extending in a first transverse direction, and at least one lens parallel to the plurality of LEDs in the first traverse direction and arranged to focus light from the LEDs; and a displacement assembly connected to the frame and engaged with the LED assembly and arranged to displace the LED assembly, with respect to the frame to a first position for an operating mode for the printhead, in which light from the plurality of LEDs illuminates media passing through the printbar in first or second process directions orthogonal to the first transverse direction and to a second position for a cleaning mode for the printhead, in which a cleaning operation for the at least one lens is enabled. 
     According to aspects illustrated herein, there is provided a lens cleaning assembly, including: an arm portion arranged to engage with a frame for a printhead and extending in a first traverse direction; and a cleaner portion arranged to engage with the frame and a housing for a light-emitting diode (LED) assembly for the printhead, the LED assembly including a plurality of LEDs and at least one lens for focusing light from the plurality of LEDs, and including a cleaning element, wherein the lens cleaning assembly is arranged to displace in the first transverse direction, with respect to the frame, to slide the cleaning element across the at least one lens for the LED assembly. 
     According to aspects illustrated herein, there is provided a method of cleaning a lens for printhead for a device capable of printing, the print head including: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs, and at least one lens arranged to focus light from the LED, the method including: engaging a lens cleaning assembly with the frame; and for a cleaning mode for the printhead: displacing the lens cleaning assembly in the first transverse direction with respect to the frame; contacting the at least one lens with a cleaning element for the lens cleaning assembly; and sliding the lens cleaning element across the at least one lens. 
     According to aspects illustrated herein, there is provided a method of operating a printhead for a device capable of printing, the printhead including: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs, and at least one lens arranged to focus light from the LED, the method including: for an operating mode for the printhead, displacing, using a displacement assembly connected to the frame and engaged with the LED assembly, the LED assembly in a first direction and, illuminating media, passing through the printbar in a first or second process direction orthogonal to the first direction, with light focused by the at least one lens; and, for a cleaning mode for the printhead, displacing, using the displacement assembly, the LED assembly in a second direction opposite the first direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: 
         FIG. 1  is a schematic block diagram of a device capable of printing and including a printhead with a cleaning assembly; 
         FIG. 2  is a perspective view of a printhead, with a lens cleaning assembly, in a cleaning mode; 
         FIG. 3  is a perspective view of the printhead in  FIG. 2 , with the lens cleaning assembly, in an operating mode; 
         FIG. 4  is a detail of area  4  of  FIG. 3 ; 
         FIG. 5  is a perspective view of the lens cleaning assembly shown in  FIG. 2 ; 
         FIG. 6  is an end view of the lens cleaning assembly shown in  FIG. 3 ; 
         FIG. 7  is a front view of area  7  in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION 
     Regarding the term “device useful for digital printing”, it should be understood that digital printing broadly encompasses creating a printed output using a processor, software, and digital-based image files. It should be further understood that xerography, for example using light-emitting diodes (LEDs), is a form of digital printing. 
     Furthermore, as used herein, the words “printer,” “printer system”, “printing system”, “printer device” and “printing device” as used herein encompasses any apparatus, such as a digital copier, bookmaking machine, facsimile machine, multi-function machine, etc. which performs a print outputting function for any purpose, while “multi-function device” and “MFD” as used herein is intended to mean a device which includes a plurality of different imaging devices, including but not limited to, a printer, a copier, a fax machine and/or a scanner, and may further provide a connection to a local area network, a wide area network, an Ethernet based network or the internet, either via a wired connection or a wireless connection. An MFD can further refer to any hardware that combines several functions in one unit. For example, MFDs may include but are not limited to a standalone printer, a server, one or more personal computers, a standalone scanner, a mobile phone, an MP3 player, audio electronics, video electronics, GPS systems, televisions, recording and/or reproducing media or any other type of consumer or non-consumer analog and/or digital electronics. 
     Moreover, although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of these embodiments, some embodiments of methods, devices, and materials are now described. 
       FIG. 1  is a schematic block diagram of device D capable of printing and including printhead  100  with cleaning assembly  102 . 
       FIG. 2  is a perspective view of printhead  100 , with lens cleaning assembly  102 , in a cleaning mode. 
       FIG. 3  is a perspective view of printhead  100  in  FIG. 2 , with lens cleaning assembly  102 , in an operating mode. 
       FIG. 4  is a detail of area  4  of  FIG. 3 . 
       FIG. 5  is a perspective view of lens cleaning assembly  102  shown in  FIG. 2 . The following should be viewed in light of  FIGS. 1 through 5 . Printhead  100  includes frame  104  and light-emitting diode (LED) assembly  106 . Assembly  106  includes: housing  108  engaged with frame  104 ; LEDs  110  on housing  108  and extending in transverse direction TD 1 ; and at least one lens  112  (hereinafter referred to as “lens  112 ”) arranged to focus light from the LEDs. Assembly  102  includes: arm portion  114  engaged with the frame and extending across the frame in direction TD 1 ; and cleaner portion  116  engaged with the frame, and including cleaning element  118 . Assembly  102  is displaceable, with respect to frame  104 , in directions TD 1  and TD 2  to slide cleaning element  118  across lens  112  to clean lens  112 . 
     In an operating mode for the printhead, for example as shown in  FIG. 3 , lens cleaning assembly  102  is displaced in direction TD 2  so that cleaning element  118  is not aligned with housing  108  in directions D 1  or D 2 , for example, at least a portion of assembly  106  is beyond element  118  in direction D 1 . In the operating mode, light L focused by lens  112  illuminates media M passing through the printhead in process direction PD 1  or PD 2 . 
     In a cleaning mode for the printhead, lens cleaning assembly  102  is displaceable in direction TD 1  (from the position for the operating mode) to contact an entirety of lens  112  with cleaning element  118 . In the cleaning mode, lens cleaning assembly  102  is displaceable in directions TD 1  and TD 2  to clean lens  112 . 
     In an example embodiment, cleaner portion  116  includes substantially “U” shaped portion  120  and frame  104  includes slot  122  and rail  124  extending in direction TD 1  and partially disposed within substantially “U” shaped portion  120 . The arm portion is arranged to slide through slot  122  in directions TD 1  and TD 2 , and portion  120  is arranged to slide along rail  124  in directions TD 1  and TD 2 , for example during the cleaning mode. The engagement of portion  120  and rail  124  blocks movement of portion  120  in at least three directions orthogonal to direction TD 1 , for example, in directions PD 1 , PD 2 , and D 2 , due to contact of portions  120 A,  120 B, and  120 C, respectively with rail  124 . In an example embodiment, the engagement of portion  120  and rail  124  blocks movement of portion  120  in any directions except TD 1  and TD 2 , for example, portion  120 D blocks movement in direction D 1  as well. 
       FIG. 7  is a front view of area  7  in  FIG. 5 . The following should be viewed in light of  FIGS. 1 through 7 . Lens cleaning assembly  102  includes bridge portion  126  connecting portions  114  and  116  and extending from the arm portion to the cleaning portion in a direction D 1 . Portion  120  extends from bridge portion  126  in direction TD 1 . Portion  116  includes holder portion  128  extending from portion  120  in a process direction PD 1 . Element  118  is removeably connected to portion  128  (to enable replacement of element  118 ) and extends from portion  128  in direction D 2  to engage lens  112  during the cleaning mode. 
     In an example embodiment, frame  104  includes rail  130  and portion  114  includes slot  132 . Rail  130  and slot  132  extend in direction TD 1 . Slot  132  opens in direction PD 1  and partially encloses rail  130 . The engagement of rail  130  and slot  132  blocks movement of portion  114  in directions D 1 , D 2 , and PD 1 . 
     Printhead  100  includes displacement assembly  134  connected to frame  104  and engaged with assembly  106 , in particular, housing  108 . For the operating mode, displacement assembly  134  is arranged to displace LED assembly  106 , with respect to frame  104 , so that light L illuminates media M passing through printbar  100  in directions PD 1  or PD 2 . For the cleaning mode, displacement assembly  134  is arranged to displace LED assembly  106 , with respect to frame  104 , so that assembly  102  is displaceable in direction TD 1 . 
     In an example embodiment, assembly  134  includes shaft  136  with an axis of rotation AR parallel to direction TD 1 . Shaft  136  is rotatable in rotational direction RD 1  to displace the LED assembly in direction D 1  to shift the printhead from the cleaning mode to the operating mode. Shaft  136  is rotatable in rotational direction RD 2 , opposite direction RD 1 , to displace the LED assembly in direction D 2 , to shift the printhead from the operating mode to the cleaning mode. 
     In an example embodiment, assembly  134  includes a blocking element blocking displacement of lens cleaning assembly  102  in direction TD 1  while printhead  100  is in the operating position. For example, handle  138  for assembly  134  includes portion  138 A that engages with handle  140  for assembly  102  (used by a user to displace assembly  102  in directions TD 1  and TD 2 ) as shown in  FIG. 3 . The engagement of portion  138 A and lips  142  of handle  140  prevents movement of assembly  102  in direction TD 1 . 
     In an example embodiment, assembly  134  includes springs  144  urging LED assembly  106  in direction D 1 . 
     In an example embodiment, printhead  100  includes assembly  102 , but not assembly  134 . That is, assembly  106  is not displaceable. In an example embodiment, printhead  100  includes assembly  134 , but not assembly  106 . That is, assembly  106  is displaceable. 
     The following should be viewed in light of  FIGS. 1 through 7 . The following describes a method of cleaning a lens for printhead for a device capable of printing. Although the method is presented as a sequence of steps for clarity, no order should be inferred from the sequence unless explicitly stated. The print head includes: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs, and at least one lens arranged to focus light from the LED. A first step engages a lens cleaning assembly with the frame. For a cleaning mode for the printhead: a second step displaces the lens cleaning assembly in the first transverse direction with respect to the frame; a third step contacts the at least one lens with a cleaning element for the lens cleaning assembly; and a fourth step slides the lens cleaning element across the at least one lens. 
     In an example embodiment, engaging the lens cleaning assembly with the frame includes: engaging an arm portion of the lens cleaning assembly with a first portion of the frame so that the arm portion extends across the frame in the first traverse direction; and engaging a cleaner portion of the lens cleaning assembly, including the cleaning element, with a second portion of the frame. In an example embodiment, engaging an arm portion of the lens cleaning assembly with a first portion of the frame includes: positioning the arm portion in a first slot in the frame; and positioning a second slot in the arm portion, extending in the first transverse direction partially about a first rail for the frame. In an example embodiment, engaging a cleaner portion of the lens cleaning assembly with a second portion of the frame includes positioning a substantially “U” shaped portion for the cleaner portion about a second rail for the frame. In an example embodiment, displacing the lens cleaning assembly in the first transverse direction with respect to the frame includes sliding the arm portion through the first slot, sliding the arm portion along the first rail, and sliding the substantially “U” shaped portion along the second rail. 
     In an example embodiment, a fifth step blocks, with the first rail, movement of the arm portion in at least three directions orthogonal to the first transverse direction, and a sixth step blocks, with the second rail, movement of the substantially “U” shaped portion in any directions except the first and second transverse directions. 
     In an example embodiment, for an operating mode the printhead: a seventh step displaces, using a displacement assembly connected to the frame and engaged with the LED assembly, the LED assembly in a first direction, and an eighth step illuminates media, passing through the printbar in a first or second process direction orthogonal to the first direction, with light focused by the at least one lens; and for the cleaning mode of the printhead, a ninth step displaces, using the displacement assembly, the LED assembly in a second direction opposite the first direction. 
     The following should be viewed in light of  FIGS. 1 through 7 . The following describes a method of operating a printhead for a device capable of printing. Although the method is presented as a sequence of steps for clarity, no order should be inferred from the sequence unless explicitly stated. The printhead includes: a frame; a light-emitting diode (LED) assembly including a housing engaged with the frame, a plurality of LEDs, and at least one lens arranged to focus light from the LED. For an operating mode for the printhead: a first step displaces, using a displacement assembly connected to the frame and engaged with the LED assembly, the LED assembly in a first direction, and a second step illuminates media, passing through the printbar in a first or second process direction orthogonal to the first direction, with light focused by the at least one lens. For a cleaning mode for the printhead, a third step displaces, using the displacement assembly, the LED assembly in a second direction opposite the first direction. 
     In an example embodiment, a fourth step rotates a shaft for the displacement assembly in a first rotational direction to displace the LED assembly in the first direction, and a fifth step rotates the shaft in a second rotational direction, opposite first rotational direction, to displace the LED assembly in the second direction. In an example embodiment, a sixth step urges the LED assembly in the first direction with at least one spring. 
     In an example embodiment, for the cleaning mode: a seventh step engages a lens cleaning assembly with the frame; an eighth step displaces, with respect to the frame, the lens cleaning assembly in a first transverse direction orthogonal to the first process direction and the first direction; a ninth step contacts the at least one lens with a cleaning element for the lens cleaning assembly; and a tenth step slides the lens cleaning element across the at least one lens. 
     Advantageously, assembly  102  and methods using assembly  102  solve the problem noted above regarding coating of lens  112  without the requirement for component removal or technical expertise. To clean lens  112 , the user merely rotates handle  138  to the position shown in  FIG. 2 , grasps handle  140  for assembly  102  and pulls/pushes handle  140  in directions TD 1 /TD 2  as needed. When the cleaning is done, the user pushes handle all the way in direction TD 2  and rotates the handle to the position shown in  FIG. 3  to enable operation of the printhead. Further, the interlocking of portion  138 A of handle  138  and lips  142  of handle  140  in the operating mode shown in  FIG. 3  prevents accidently or unintentional displacement of element  118  across lens  112  during operation of the printhead. 
     Displacement assembly  134  enables clearances in printhead  100  for operation of assembly  102 , while ensuring optimal light intensity on media M. For example, it is desirable to minimize distance DIS, shown in  FIG. 1 , to enable maximum light intensity on media M to ensure optimal results for the printhead. However, an optimal distance DIS during operation of printhead  100  may not provide adequate clearance for operation of assembly  102 . Advantageously however; by displacing assembly  106  in direction D 2  for the cleaning mode, distance DIS is increased to enable the clearance required for displacing element  118  across lens  112 . Further, when operation of printhead  100  is required, assembly  102  is displaced in direction TD 2  and assembly  106  is displaced in direction D 1  to a desired value for DIS. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.