Abstract:
A method of manufacturing an inkjet printer component and an inkjet printer component electropolishing device are provided. The method includes positioning an electrode in a fluid passageway of an inkjet printer component, the electrode including a conductive face and a nonconductive face; polishing a side of the fluid passageway by: biasing the nonconductive face of the electrode toward a side of the fluid passageway such that the conductive face of the electrode does not contact any portion of the fluid passageway; providing an electrolytic fluid to the fluid passageway of the inkjet printer component; and applying a voltage between the electrode and the inkjet printer component.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to inkjet printing and, in particular to a method of manufacturing inkjet printer components. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electropolishing of inkjet printer components is known, see, for example, European Patent Application Publication EP 0 854 040 A2, published on Jul. 22, 1998, and is used to remove burrs, EDM splatter, flakes, etc. produced during the manufacturing processes used to fabricate these components. 
         [0003]    Referring to  FIG. 1 , EP 0 854 040 A2 discloses an electropolishing process in which an electrode  10  are positioned inside a fluid cavity  12 , commonly referred to as a bore, of a drop generator body  14 . Typically, electrode  10  is a wire or small diameter rod and is secured in place with a fixture (not shown) at both ends of drop generator body  14 . Drop generator body  14  along with electrode  10  is then immersed in an electropolishing solution and an appropriate voltage applied between drop generator body  14  and electrode  10  to affect electropolishing of the inkjet printer component. 
         [0004]    While positioning internal electrode  10  within fluid cavity  12  of drop generator body  14  can be accomplished relatively easily, placement of an electrode in fluid passageway  16 , commonly referred to as a slot, has been problematic. Fluid passageway  16  is sufficiently narrow, for example, approximately 0.015 inches wide in some drop generator bodies, that the risk of accidental contact between electrode  10  and drop generator body  14  becomes significant. Any such contact occurring during the electropolishing process can produce an electrical short and arcing that will destroy the drop generator. 
         [0005]    Additionally, a gap between electrode  10  and the walls of the slot must be sufficiently large to allow electrolytic fluid to flow through the gap between the walls of fluid passageway  16  and electrode  10 . It is difficult to accomplish this without significantly increasing the risk of electrode  10  contacting drop generator body  14 . Also, fluid passageway  16  does not extent to the ends of the drop generator body  14 . As such, fixtures located at the ends of fluid passageway  14  can not be used to retain electrode  10  in position within fluid passageway  16 . 
         [0006]    Accordingly, EP 0 854 040 A2 discloses a pulsing technique in which the electropolishing solution is pulsed in order to electropolish regions of the inkjet printer component, like fluid passageway  16 , that can not accommodate electrode  10 . However, it has been found that using the pulsing technique can produce inconsistent results depending on the characteristics and dimensions of fluid passageway  16 . 
         [0007]    Accordingly, a need exists to be able to electropolish inkjet printer components that traditionally are unable to accommodate positioning of an electrode within the component. 
       SUMMARY OF THE INVENTION 
       [0008]    According to a feature of the present invention, a method of manufacturing an inkjet printer component, the inkjet printer component including a fluid passageway, the method including positioning an electrode in the fluid passageway of the inkjet printer component, the electrode including a conductive face and a nonconductive face; polishing a side of the fluid passageway by: biasing the nonconductive face of the electrode toward a side of the fluid passageway such that the conductive face of the electrode does not contact any portion of the fluid passageway; providing an electrolytic fluid to the fluid passageway of the inkjet printer component; and applying a voltage between the electrode and the inkjet printer component. 
         [0009]    According to another feature of the present invention, an inkjet printer component electropolishing device includes an electrode including a nonconductive face and a conductive face. The conductive face of the electrode is at least partially bounded by a nonconductive material such that a conductive window is located on the conductive face of the electrode. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    In the detailed description of the preferred embodiments of the invention presented below, reference is made to the accompanying drawings, in which: 
           [0011]      FIG. 1  is a schematic illustration of a prior art method of manufacturing an inkjet printer component; 
           [0012]      FIG. 2  is a schematic illustration of an example embodiment of an electrode component of the present invention; 
           [0013]      FIG. 3  is a schematic illustration of another example embodiment of an electrode component of the present invention; 
           [0014]      FIG. 4  is a schematic illustration of the electrode component of  FIG. 3  shown in an electrode fixture; 
           [0015]      FIG. 5  is a schematic illustration of the electrode fixture of  FIG. 3  positioned in an inkjet printer component; 
           [0016]      FIG. 6  is a schematic illustration of an example embodiment of the present invention; and 
           [0017]      FIG. 7  is a schematic illustration of another example embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. It is to be understood that elements not specifically shown or described may take various forms well known to those skilled in the art. 
         [0019]    EP 0 854 040 A2 also discusses electrochemical polishing (commonly referred to as electropolishing) and electrochemical deburring as two electrochemical methods for removing burrs, splatter, flakes, etc. from machined inkjet printer components. Typically, these processes differ in the types of electrolytic fluids used. Appropriate electrolytic fluids for use in these processes are well known in the electropolishing and electrochemical deburring industries. These methods and associated electrolytic fluids are interchangeable within the context of the present invention. 
         [0020]    Referring to  FIG. 2 , a schematic illustration of an example embodiment of an electrode  20  component of the present invention is shown. Electrode  20  is a single sided electrode. As electrode  20  is electrically conductive on only one side, the likelihood of electrode  20  contacting the inkjet printer component and causing arcing during the polishing process is reduced. As shown in  FIG. 2 , single sided electrode  20  includes a thin nonconductive ceramic plate  22  with a thin conductive coating or layer  24  over one face  26  of the two faces  26 ,  28  of electrode  20 . Conductive layer  24  can include a metal coating, such as gold, that is deposited on ceramic plate  22  using conventional methods such as sputtering or other types of vacuum deposition. When other materials are used, the material selected for conductive layer  24  should be sufficiently conductive to ensure uniform electropolishing across a width of electrode  20 . Electrode  20  can also include a non-conductive region  32  on face  26  by not coating all of face  26  with conductive layer  24 . 
         [0021]    Electrode  20  includes a plurality of dielectric shields  30  positioned on face  26  to cover portions of conductive layer. Dielectric shields  30  can be in the form of narrow non-conductive tape strips, fine polymeric or glass fibers, or a photoresist material. Dielectric shields  30  serve as spacers to prevent accidental contact between conductive layer  24  of face  26  and one or more of the sides of the fluid passageway side of the inkjet printer component. 
         [0022]    During electropolishing of the inkjet printer component, single sided electrode  20  can be positioned in the fluid passageway of the component with non-conductive face  28  in contact with one of the sides of the fluid passageway without risk of electrode  20  making electrical contact with that side of the fluid passageway. A biasing or retaining fixture can be used to locate single sided electrode  20  in the fluid passageway with non-conductive face  28  in contact with a side of the fluid passageway. With single sided electrode  20  biased or retained in position with non-conductive face  28  in contact with the side of the fluid passageway, the gap between conductive face  26  of electrode  20  and the side of the fluid passageway to be electropolished is wide enough to allow electrolytic fluid to flow through the gap thus allowing electropolishing to occur when a voltage is applied to electrode  20  and an inkjet printer component  52 , for example, drop generator body  54  (shown in  FIG. 5 ). 
         [0023]    The specific voltage applied to electrode  20  and inkjet printer component  52  can be any voltage that is sufficient to cause electropolishing of inkjet printer component  52  but does not cause pitting of inkjet printer component  52 . Typically, the specific applied voltage will depend on the composition of the electrolytic fluid used in the electropolishing process. The electrolytic fluids used in the electropolishing process can be, for example, the electrolytic fluids discussed above with reference to EP 0 854 040 A2. However, other types of electrolytic fluids can be used. 
         [0024]    Using single sided electrode  20 , it is now possible to effectively electropolish a side of the fluid passageway. After a first side of the fluid passageway is completely electropolished, electrode  20  can be turned around and repositioned in the fluid passageway such that a second side of the fluid passageway can be electropolished. 
         [0025]    When dielectric shields  30  are included on electrode  20 , portions of the fluid passageway of the inkjet printer component can be masked leaving those portions un-electropolished. As such, the fluid passageway can be polished in one or more steps. In this situation, electropolishing takes place with electrode  20  in one positions within the fluid passageway. Then, electrode  20  is indexed along the length of fluid passageway such that dielectric shields  30  no longer mask the same portion of the fluid passageway when compared to the previous step. Electropolishing then takes place after electrode  20  has been repositioned or indexed along the length of the fluid passageway. Indexing of electrode  20  can be accomplished manually by an operator or automatically. Additionally, indexing of electrode  20  can be a discrete step or alternatively electrode  20  can be continuously moved back and forth along the length of fluid passageway. 
         [0026]    Referring to  FIG. 3 , a schematic illustration of another example embodiment of electrode  20  is shown. Single sided electrode  20  includes a conductive face  26  made from a conductive material  34 , for example, a copper or beryllium copper foil, and a nonconductive face  28  made from a non-conductive material  36 , for example, a polymeric sheet, laminated to one side of conductive material  34 . Polyimide materials such as Kapton or Upilex are suitable non-conductive polymeric sheet materials. As shown in  FIG. 3 , conductive face  26  is partially covered by a nonconductive material  38 , for example, a polymeric sheet like the one described above, such that a polishing or conductive window  40  is formed. The height  42  of polishing or conductive window can be designed to align with the height  43  of the wall or side of the fluid passageway to be electropolished. This further reduces the likelihood of electrical arcing when voltage is applied to electrode  20  and helps to concentrate or direct electropolishing to the side wall of the fluid passageway. 
         [0027]    Referring to  FIG. 4 , a schematic illustration of electrode  20  is shown mounted to an electrode fixture. Electrode  20  is positioned within the fluid passageway using fixture  44 . Fixture  44  helps to locate and bias electrode  20  in the fluid passageway so that the insulated or nonconductive face  28  of electrode  20  is closer to a wall or side of the fluid passageway than the un-insulated or conductive face  26  of electrode  20 . A plate  46 , for example, a Macor® ceramic material plate, of fixture  44  secures at least one end of single sided electrode  20  to a conventional electrode mounting block  48  of fixture  44 . 
         [0028]    Referring to  FIG. 5 , a schematic illustration of electrode  20  positioned in a fluid passageway  50  of an inkjet printer component  52 , for example, a drop generator body  54 , is shown. Plate  46  rests on a surface  56  of drop generator body  54  so as to control the depth of insertion of electrode  20  into fluid passageway  50  of drop generator body  54 . 
         [0029]    Electrode guides  58  can be used to bias or stabilize another end of electrode  20  within drop generator body  54 . Electrode guides  58  can be at least one nonconductive, for example, plastic, rod  60  positioned in a fluid cavity  62  of drop generator body  54  and located on the each side of electrode  20  such that the inserted end of electrode  20  is stabilized and appropriately positioned within inkjet printer component  52 . Drop generator body  54  can be, for example, of the type disclosed in U.S. Pat. No. 4,999,644, issued to Katerberg et al. on Mar. 12, 1991, or in European Patent No. EP 1 013 422 B1, published on Aug. 23, 2006. 
         [0030]    Referring to  FIG. 6 , a schematic illustration of an example embodiment of the present invention is shown. In this embodiment, electrolytic fluid is actively flowed between electrode  20  and the side of fluid passageway being polished. A pump  64  pumps electrolytic fluid  65  from a reservoir  66  through supply lines  67  into drop generator body  54 . Electrolytic fluid  65  enters drop generator body though inlet ports  68  located at each end  70  of drop generator body  54 . Inlet ports  68  are connected to fluid cavity  62  of drop generator body  54 . Electrolytic fluid  65  flows past plastic rods  60  located in fluid cavity  62  and flows out of drop generator body  54  through the gap  72  (shown in  FIG. 5 ) between electrode  20  and the wall or side of fluid passageway  50  being electropolished. After exiting fluid passageway  50 , electrolytic fluid  65  flows over the sides of drop generator body  54  and drips back into reservoir  66 . A power supply (like the one shown in  FIG. 7 ) is used to establish the voltage between electrode  20  and drop generator body  54  needed for electropolishing fluid passageway  50 . 
         [0031]    Referring to  FIG. 7 , a schematic illustration of another example embodiment of the present invention is shown. In this embodiment, drop generator body  54 , electrode  20 , and fixture  44  are immersed in electrolytic fluid  76  contained in a reservoir  74 . A power supply  78  in electrical communication with electrode  20  and drop generator body  54  provides the voltage needed for electropolishing fluid passageway  50 . 
         [0032]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention. 
       PARTS LIST 
       [0000]    
       
         
           
               10  Electrode 
               12  Fluid Cavity 
               14  Drop Generator Body 
               16  Fluid Passageway 
               20  Electrode 
               22  Ceramic Plate 
               24  Conductive Layer 
               26  Face 
               28  Non-Conductive Face 
               30  Dielectric Shields 
               32  Non-Conductive Region 
               34  Conductive Material 
               36  Non-Conductive Material 
               38  Non-Conductive Material 
               40  Conductive Window 
               42  Height Of Conductive Window 
               43  Height Of Wall Of Fluid Passageway 
               44  Fixture 
               46  Plate 
               48  Electrode Mounting Block 
               50  Fluid Passageway 
               52  Inkjet Printer Component 
               54  Drop Generator Body 
               56  Surface 
               58  Electrode Guides 
               60  Rod 
               62  Fluid Cavity 
               64  Pump 
               65  Electrolytic Fluid 
               66  Reservoir 
               67  Supply Lines 
               68  Inlet Ports 
               70  End Of Drop Generator Body 
               72  Gap 
               74  Reservoir 
               76  Electrolytic Fluid 
               78  Power Supply