Patent Publication Number: US-7222937-B2

Title: Drop generating apparatus

Description:
BACKGROUND OF THE DISCLOSURE 
     The disclosure relates generally to drop emitting apparatus including for example drop jetting devices. 
     Drop on demand ink jet technology for producing printed media has been employed in commercial products such as printers, plotters, and facsimile machines. Generally, an ink jet image is formed by selective placement on a receiver surface of ink drops emitted by a plurality of drop generators implemented in a printhead or a printhead assembly. For example, the printhead assembly and the receiver surface are caused to move relative to each other, and drop generators are controlled to emit drops at appropriate times, for example by an appropriate controller. The receiver surface can be a transfer surface or a print medium such as paper. In the case of a transfer surface, the image printed thereon is subsequently transferred to an output print medium such as paper. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic block diagram of an embodiment of a drop-on-demand drop emitting apparatus. 
         FIG. 2  is a schematic block diagram of an embodiment of a drop generator that can be employed in the drop emitting apparatus of  FIG. 1 . 
         FIG. 3  is a schematic elevational view of an embodiment of an ink jet printhead assembly. 
         FIGS. 4A ,  4 B,  4 C,  4 D are schematic diagrams of embodiments of manifold structures that can be employed in the ink jet printhead of  FIG. 3 . 
         FIG. 5A  schematically illustrates the relative positioning of the manifold structures of  FIGS. 4A and 4B . 
         FIG. 5B  schematically illustrates the relative positioning of the manifold structures of  FIGS. 4C and 4D . 
         FIG. 6  is a schematic diagram of a manifold network formed of the manifold structures of  FIGS. 4A ,  4 B,  4 C,  4 D. 
         FIG. 7  is a schematic isometric view generally illustrating a plurality of ink drop generators that are fluidically coupled to a finger manifold. 
         FIG. 8  schematically illustrates an arrangement of ink drop generators fluidically coupled to the manifold structure of  FIG. 4B . 
         FIG. 9  schematically illustrates an arrangement of ink drop generators fluidically coupled to the manifold structure of  FIG. 4C . 
         FIG. 10  schematically illustrates an arrangement of ink drop generators fluidically coupled to the manifold structures of  FIGS. 4B and 4C , wherein such manifold structures are positioned side by side. 
         FIG. 11  schematically illustrates an arrangement of ink drop generators of the printhead of  FIG. 3 . 
         FIG. 12  schematically illustrates an arrangement of nozzles of the printhead of  FIG. 3 . 
         FIG. 13  schematically illustrates a further arrangement of nozzles of the printhead of  FIG. 3 . 
         FIG. 14  schematically illustrates another arrangement of nozzles of the printhead of  FIG. 3 . 
         FIG. 15  schematically illustrates still another arrangement of nozzles of the printhead of  FIG. 3 . 
         FIG. 16  schematically illustrates a further arrangement of nozzles of the printhead of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
       FIG. 1  is schematic block diagram of an embodiment of a drop-on-demand printing apparatus that includes a controller  10  and a printhead assembly  20  that can include a plurality of drop emitting drop generators. The controller  10  selectively energizes the drop generators by providing a respective drive signal to each drop generator. Each of the drop generators can employ a piezoelectric transducer. As other examples, each of the drop generators can employ a shear-mode transducer, an annular constrictive transducer, an electrostrictive transducer, an electromagnetic transducer, or a magnetorestrictive transducer. The printhead assembly  20  can be formed of a stack of laminated sheets or plates, such as of stainless steel. 
       FIG. 2  is a schematic block diagram of an embodiment of a drop generator  30  that can be employed in the printhead assembly  20  of the printing apparatus shown in  FIG. 1 . The drop generator  30  includes an inlet channel  31  that, in embodiments disclosed herein, receives ink  33  from an ink containing finger manifold structure  161 ,  162 ,  163 ,  164  ( FIGS. 4A-4D ,  5 A,  5 B,  6 - 10 ). The ink  33  flows into an ink pressure or pump chamber  35  that is bounded on one side, for example, by a flexible diaphragm  37 . An electromechanical transducer  39  is attached to the flexible diaphragm  37  and can overlie the pressure chamber  35 , for example. The electromechanical transducer  39  can be a piezoelectric transducer that includes a piezo element  41  disposed for example between electrodes  43  that receive drop firing and non-firing signals from the controller  10 . Actuation of the electromechanical transducer  39  causes ink to flow from the pressure chamber  35  through an outlet channel  45  to a drop forming nozzle or orifice  47 , from which an ink drop  49  is emitted toward a receiver medium  48  that can be a transfer surface, for example. 
     The ink  33  can be melted or phase changed solid ink, and the electromechanical transducer  39  can be a piezoelectric transducer that is operated in a bending mode, for example. 
       FIG. 3  is a schematic elevational view of an embodiment of an ink jet printhead assembly  20  that can implement a plurality of drop generators  30  ( FIG. 2 ) as an array of drop generators. The ink jet printhead assembly includes a fluid channel layer or substructure  131 , a diaphragm layer  137  attached to the fluid channel layer  131 , and transducer layer  139  attached to the diaphragm layer  137 . The fluid channel layer  131  implements the fluid channels and chambers of the drop generators  30 , while the diaphragm layer  137  implements the diaphragms  37  of the drop generators. The transducer layer  139  implements the piezoelectric transducers  39  of the drop generators  30 . The nozzles of the drop generators  30  are disposed on an outside surface  131 A of the fluid channel layer  131  that is opposite the diaphragm layer  137 , for example. 
     By way of illustrative example, the diaphragm layer  137  comprises a metal plate or sheet such as stainless steel that is attached or bonded to the fluid channel layer  131 . Also by way of illustrative example, the fluid channel layer  131  can comprise a laminar stack of plates or sheets, such as stainless steel. 
     For reference, an XYZ coordinate system can be associated with the printhead assembly  20 , wherein the XY plane is parallel to the outside surface  131 A of the printhead that contains the ink drop emitting nozzles  47 , and wherein the Y-axis is orthogonal to the plane of  FIG. 3 . The layering of the fluid channel layer  131 , the diaphragm layer  137 , and the transducer layer  139  is along the Z-axis. For further reference, the outside surface  131 A of the fluid channel layer  131  that contains the drop emitting nozzles  47  can be considered the front surface of the printhead, while the transducer layer  139  can be considered back of the printhead. Also, the outside surface  131 A that contains the drop emitting nozzles  47  can be called the nozzle side of the printhead. By way of illustrative example, the receiver surface can be moved along the Y-axis relative to the printhead assembly. 
       FIGS. 6-10  schematically illustrate embodiments of the fluid channel structure of the fluid channel layer  131  of the printhead  20  of  FIG. 3 . The fluid channel structure can be implemented by openings formed in various layers of a laminar structure that comprises the fluid channel layer  131 . For ease of illustration, the fluid conveying volumes of the fluid channel structure are shown without the walls that define such volumes. Also, to facilitate understanding, the various portions of the fluid channel structure will be illustrated in different figures. 
       FIG. 6  is an embodiment of a manifold network that is formed of a plurality of first through fourth manifold structures  51 ,  52 ,  53 ,  54 , embodiments of which are individually illustrated in  FIGS. 4A-4D  for ease of viewing.  FIG. 5A  illustrates the relative positioning of the first manifold structure  51  and the second manifold structure  52 , while  FIG. 5B  illustrates the relative positioning of the third manifold structure  53  and the fourth manifold structure  54 . 
     The first manifold structure  51  includes a first ink distributing primary manifold  61 , and the second manifold structure  52  includes a second ink distributing primary manifold  62 . The first and second primary manifolds  61 ,  62  can extend longitudinally along the X-axis, and can be generally parallel. The first and second primary manifolds  61 ,  62  can also be side by side or overlapping along the Z-axis. The first and second primary manifolds  61 ,  62  can be adjacent a longitudinal edge of the printhead fluid channel layer  131 , and can receive ink through respective input ports  61 A,  62 A. 
     A plurality of first intermediate or finger manifolds  161  are fluidically coupled to the first primary manifold  61  and extend generally transversely from the first primary manifold toward a middle portion of the fluid channel layer  131 . By way of illustrative example, the first finger manifolds can be substantially parallel to each other (i.e, substantially mutually parallel), and the longitudinal extents of the first finger manifolds  161  can be slanted or oblique to the Y-axis and to the X-axis. 
     A plurality of second intermediate or finger manifolds  162  are fluidically coupled to the second primary manifold  62  and extend generally transversely from the second primary manifold  62  toward a middle portion of the fluid channel layer  131 . As illustrated more particularly in  FIG. 5A , the second finger manifolds  162  are interleaved with the first finger manifolds  162 . By way of illustrative example, the second finger manifolds  162  can be substantially parallel to each other (i.e., substantially mutually parallel), and the longitudinal extents of the second finger manifolds  162  can be slanted or oblique to the Y-axis and to the X-axis. 
     The first finger manifolds  161  and the second finger manifolds  162  can be substantially mutually parallel, and can thus be side by side along the longitudinal extents of the first and second primary manifolds  61 ,  62 . 
     In this manner, the first finger manifolds  161  comprise a first linear array of generally laterally extending slanted finger manifolds, and the second finger manifolds  162  comprise a second linear array of generally laterally extending slanted finger manifolds. These first and second linear arrays of slanted finger manifolds extend along the X-axis, and the interleaved first and second finger manifolds together form a composite linear array of generally laterally extending slanted finger manifolds that extends along the X-axis. The first finger manifolds  161  can be considered a first linear sub-array of the composite linear array, and the second finger manifolds  162  can be considered a second linear sub-array of the composite linear array. 
     The third manifold structure  53  includes a third ink distributing primary manifold  63 , and the fourth manifold structure  54  includes a fourth ink distributing primary manifold  64 . The third and fourth primary manifolds  63 ,  64  can extend longitudinally along the X-axis. The third and fourth primary manifolds  63 ,  64  can further be generally parallel to the first and second primary manifolds  61 ,  62 . The third and fourth primary manifolds  63 ,  64  can also be side by side or overlapping along the Z-axis. The third and fourth primary manifolds can be located for example adjacent an edge of the printhead fluid channel layer  131  that is opposite the edge at which the first and second primary manifolds  61 ,  62  are adjacently located, and can receive ink through respective input ports  63 A,  64 A. 
     A plurality of third intermediate or finger manifolds  163  are fluidically coupled to the third primary manifold  63  and extend generally transversely from the third primary manifold  63  toward a middle portion of the fluid channel layer  131 . By way of illustrative example, the third finger manifolds can be substantially parallel to each other (i.e., substantially mutually parallel), and the longitudinal extents of the third finger manifolds  163  can be slanted or oblique to the Y-axis and to the X-axis. The third finger manifolds  163  can further be substantially parallel to the first finger manifolds  61  or the second finger manifolds  62 . 
     A plurality of fourth intermediate or finger manifolds  164  are fluidically coupled to the fourth primary manifold  64  and extend generally transversely from the fourth primary manifold  64  toward a middle portion of the fluid channel layer  131 . As illustrated more particularly in  FIG. 5B , the fourth finger manifolds  164  are interleaved with the third finger manifolds  163 . By way of illustrative example, the fourth finger manifolds  164  can be substantially parallel to each other (i.e, substantially mutually parallel), and the longitudinal extents of the fourth finger manifolds  164  can be slanted or oblique to the Y-axis and to the X-axis. The fourth finger manifolds  164  can further be substantially parallel to the first finger manifolds  61  or the second finger manifolds  62 . 
     The third and fourth finger manifolds  163 ,  164  can be substantially mutually parallel, and thus can be side by side along the longitudinal extents of the third and fourth primary manifolds  63 ,  64 . 
     In this manner, the third finger manifolds  163  comprise a third linear array of generally laterally extending slanted finger manifolds, and the fourth finger manifolds  164  comprise a fourth linear array of generally laterally extending slanted finger manifolds. The third and fourth linear arrays extend along the X-axis, and the interleaved third and fourth finger manifolds together form a composite linear array of generally laterally extending slanted finger manifolds that extends along the X-axis. The third finger manifolds  163  can be considered a first linear sub-array of the composite linear array, and the fourth finger manifolds  164  can be considered a second linear sub-array of the composite linear array. 
     By way of illustrative example, the first, second, third and fourth finger manifolds  161 ,  162 ,  163 ,  164  can be substantially mutually parallel. Also, the first finger manifolds  161  can be generally aligned with the fourth finger manifolds  164 , while the second finger manifolds  162  can be generally aligned with the third finger manifolds  163 . 
     The first and second primary manifolds  61 ,  62  can receive inks of different colors or of the same color. By way of illustrative example, the first and second primary manifolds  61 ,  62  can receive magenta (M) ink and cyan (C) ink respectively. The third and fourth primary manifolds  63 ,  64  can receive inks of different colors or of the same color. By way of illustrative example, the third and fourth primary manifolds  63 ,  64  can receive yellow (Y) ink and black (K) ink respectively. For ease of reference, some of the elements in the drawings include the designations M, C, Y, or K for the illustrative example wherein the first through fourth primary manifolds  61 - 64  respectively distribute magenta, cyan, yellow and black inks. 
     As another example, the first and second primary manifolds  61 ,  62  can receive ink of a first color, while the third and fourth primary manifolds  63 ,  64  receive ink of a second color. As yet another example, all of the primary manifolds  61 - 64  receive ink of the same color. As still another example, the first and second primary manifolds  61 ,  62  respectively receive inks of a first color and a second color, while the third and fourth primary manifolds  63 ,  64  receive ink of a third color. Other combinations can also be employed. 
     As generally illustrated in  FIG. 7  for a representative finger manifold  161 , a plurality of ink drop generators  30  can be fluidically coupled to each of the finger manifolds  161 ,  162 ,  163 ,  164 . The ink drop generators  30  can be located on either side of a finger manifold. Each ink drop generator is located such that its outlet channel  45  is adjacent the associated finger manifold to which it is coupled and extends through a gap between the associated finger manifold and an adjacent finger manifold. The ink pressure chambers  35  of the ink drop generators  30  are located behind or above the associated finger manifolds, while the nozzles  47  are located in front of or below the associated finger manifolds. 
     By way of illustrative example, as shown schematically in  FIGS. 8-10  for adjacent fragmentary portions of the manifold structures  51  and  52 , the ink drop generators  30  can be arranged in slanted linear columns of drop generators having outlet channels extending between adjacent finger manifolds  161 / 162  and  163 / 164 . The ink drop generators  30  of each column can be alternatingly fluidically connected to the associated adjacent finger manifolds. In this manner, the ink drop generators associated with an adjacent pair of finger manifolds can be alternatingly fluidically coupled to different primary manifolds. 
       FIG. 11  is a schematic view of an embodiment of an arrangement of the drop generators  30  of the printhead  20  as viewed from the nozzle side  131 A of the printhead, for the illustrative example wherein the first through fourth primary manifolds  61 ,  62 ,  63 ,  64  respectively provide magenta (M), cyan (C), yellow (Y) and black (K) primary colors. For ease of viewing, only the ink chambers  35  and the outlet channels  45  are shown in  FIG. 11 . Although not shown, the finger manifolds would extend between the columns of outlet channels  45  and also along the outboard side of the outboard columns of outlet channels. 
     In the embodiment shown in  FIG. 11 , the drop generators are grouped or arranged in two arrays A, B of ink drop generators  30 . Each of the ink drop generators  30  of the array A is fluidically coupled to one of the first finger manifolds  161  or one of the second finger manifolds  162 , and thus is fluidically coupled to the first primary manifold  61  or to the second primary manifold  62 . Each of the ink drop generators  30  of the array B is fluidically coupled to one of the third finger manifolds  163  or one of the fourth finger manifolds  164 , and thus is fluidically coupled to the third primary manifold  63  or to the fourth primary manifold  64 . For ease of reference, the drop generators are identified with the letters M, C, Y or K to indicate their respective fluidic connections to the finger manifolds  161 ,  162 ,  163 , or  164  for the illustrative example wherein the primary manifolds  61 ,  62 ,  63 ,  64  provide magenta (M), cyan (C), yellow (Y) and black (K) primary colors. 
     The ink drop generators  30  of the array A are more particularly arranged in a linear array of slanted, side by side columnar arrays AC 1 -ACN. The linear array extends along the X-axis, and the slanted columnar arrays can be substantially mutually parallel and slanted or oblique relative to the X-axis as well as the Y-axis. Each columnar array includes the same number of ink drop generators, and the columnar arrays can be substantially aligned along the Y-axis such that the ink drop generators  30  form rows AR 1 -AR 8  that can be substantially mutually parallel and generally parallel to the X-axis. The drop generators  30  in each row can be co-linear or offset along an axis of the row, while the drop generators in each columnar array can be co-linear or offset along an axis of the columnar array, for example. Eight rows are shown as an illustrative example and it should be appreciated that the number of rows can be appropriately selected. The ink drop generators  30  of the array A can conveniently be referenced by their column and row location (e.g., AC 1 /AR 1 , AC 1 /AR 2 , etc.). 
     By way of illustrative example, in each column, the ink drop generators of the odd numbered rows AR 1 , AR 3 , AR 5 , AR 7  can be fluidically connected to an associated first finger manifold  161 , while the ink drop generators of the even numbered rows AR 2 , AR 4 , AR 6 , AR 8  can be connected to an associated second finger manifold  162  that is adjacent to the associated first finger manifold  161 . In other words, the ink drop generators of each column AC 1 -ACN are alternatingly fluidically coupled, row by row, to one of an associated pair of finger manifolds, wherein the associated pair of finger manifolds comprises a first finger manifold  161  and a second finger manifold  162  that is adjacent to the first finger manifold  161 . In this manner, the ink drop generators of the odd numbered rows AR 1 , AR 3 , AR 5 , AR 7  can be fluidically coupled to the first primary manifold  61 , while ink drop generators of the even numbered rows AR 2 , AR 4 , AR 6 , AR 8  can be fluidically coupled to the second primary manifold  62 . Thus, the rows AR 1 -AR 8  of drop generators can be alternatingly fluidically coupled, row by row, to the first primary manifold  61  and the second primary manifold  62 . 
     In this manner, the array A can also be considered as a plurality of offset rows AR 1 -AR 8  of ink drop generators, wherein each row of drop generators is fluidically coupled to a common primary manifold. 
     Each slanted column AC 1 -ACN of drop generators can also be considered as being comprised of interleaved sub-columns, wherein one sub-column includes drop generators in the odd numbered rows AR 1 , AR 3 , AR 5 , AR 7  while another sub-column includes drop generators in the even numbered rows AR 2 , AR 4 , AR 6 , AR 8 . In this manner, the ink drop generators of one sub-column are fluidically coupled to the associated first finger manifold  161  while the ink drop generators of the other sub-column are fluidically coupled to the associated second finger manifold  162 . For the illustrative example wherein the first finger manifolds  161  provide magenta ink and wherein the second finger manifolds  162  provide cyan ink, each slanted column AC 1 -ACN is formed of a magenta (M) sub-column interleaved with a cyan (C) sub-column. 
     The ink drop generators  30  of the array B are more particularly arranged in a linear array of slanted, side by side columnar arrays BC 1 -BCN. The linear array extends along the X-axis, and the slanted columnar arrays can be substantially mutually parallel and slanted or oblique relative to the X-axis as well as the Y-axis. Each columnar array includes the same number of ink drop generators, and the columnar arrays can be substantially aligned along the Y-axis such that the ink drop generators  30  form rows BR 1 -BR 8  that can be substantially mutually parallel and generally parallel to the X-axis. The drop generators in each row can be co-linear or offset along an axis of the row, while the drop generators in each column can be co-linear, or offset or staggered along an axis of the column, for example. Eight rows are shown as an illustrative example and it should be appreciated that the number of rows can be appropriately selected. The ink drop generators of the array B can conveniently be referenced by their column and row location (e.g., BC 1 /BR 1 , BC 1 /BR 2 , etc.). 
     By way of illustrative example, in each columnar array, the ink drop generators of the odd numbered rows BR 1 , BR 3 , BR 5 , BR 7  are fluidically connected to an associated third finger manifold  163 , while the ink drop generators of the even numbered rows BR 2 , BR 4 , BR 6 , BR 8  are fluidically connected to an associated fourth finger manifold  164  that is adjacent to the associated third finger manifold  163 . In other words, the ink drop generators of each column BC 1 -BCN can be alternatingly fluidically coupled, row by row, to one of an associated pair of finger manifolds, wherein the associated pair of finger manifolds comprises a third finger manifold  163  and a fourth finger manifold  164  that is adjacent to the third finger manifold  163 . In this manner, the ink drop generators of the odd numbered rows BR 1 , BR 3 , BR 5 , BR 7  can be fluidically coupled to the third primary manifold  63 , while ink drop generators of the even numbered rows BR 2 , BR 4 , BR 6 , BR 8  can be fluidically coupled to the fourth primary manifold  64 . Thus, the rows BR 1 -BR 8  of drop generators can be alternatingly fluidically coupled, row by row, to the third primary manifold  63  and the fourth primary manifold  64 . 
     The array B can thus be considered as a plurality of offset rows BR 1 -BR 8  of ink drop generators, wherein each row of drop generators is fluidically coupled to a common primary manifold. 
     Each slanted columnar array BC 1 -BCN of drop generators can also be considered as being comprised of interleaved sub-columns, wherein one sub-column includes drop generators in the odd numbered rows BR 1 , BR 3 , BR 5 , BR 7  while another sub-column includes drop generators in the even numbered rows BR 2 , BR 4 , BR 6 , BR 8 . In this manner, the ink drop generators of one sub-column are fluidically coupled to the associated third finger manifold  163  while the ink drop generators of the other sub-column are fluidically coupled to the associated fourth finger manifold  164 . For the illustrative example wherein the third finger manifolds  163  provide yellow ink and wherein the fourth finger manifolds  164  provide black ink, each slanted column BC 1 -BCN is formed of a yellow (Y) sub-column interleaved with a black (K) sub-column. 
     By way of illustrative example, the array B can comprise a replica or copy of the array A that is contiguously adjacent the array A along the Y axis, such that each columnar array AC 1 -ACN of the array A has an associated columnar array BC 1 -BCN of the array B displaced therefrom along the Y axis. For ease of reference, a columnar array of the array A and its associated columnar array of the array B can be referred to as being vertically associated. Depending upon implementation, each A array columnar array can be aligned with the associated B array columnar array along the X-axis, such that each A array drop generator in a given array A columnar array is aligned along the X-axis with an associated drop generator in a vertically associated array B columnar array. In this manner, vertically associated ink drop generators (e.g., AC 1 /AR 1  and BC 1 /BR 1 ) are on a line that is substantially parallel to the Y-axis. Alternatively, each A array columnar array can be displaced or offset relative to the associated B array columnar array along the X-axis. For the illustrative example wherein the first through fourth finger manifolds  61 - 64  respectively provide magenta, cyan, yellow and black ink, each M drop generator can be associated with a Y drop generator, and each C drop generator can be associated with a K drop generator, as schematically depicted in  FIG. 11 . 
     The drop generator arrays A and B can be configured such that slanted columnar arrays BC 1  through BCN- 1  can be columnarly aligned with the slanted columnar arrays AC 2  through ACN. In this manner, composite slanted columns AC 2 /BC 1 , AC 3 /BC 2 , etc. can formed. The drop generator arrays A and B can be relatively positioned so as to have uniform spacing between drop generators in each of the composite slanted columnar arrays AC 2 /BC 1 -ACN/BCN- 1 . 
       FIGS. 12-16  schematically illustrate embodiments of arrangements of the nozzles  47  of the printhead  20 , as viewed from the nozzle side  131 A of the printhead. Since the nozzles  47  are at the ends of the outlet channels  45  of the drop generators  30  of the arrays A, B, the nozzles  47  are arranged in nozzle arrays that can be conveniently called nozzle arrays NA, NB. The nozzle arrays NA, NB are generally side by side along the Y-axis such that the nozzle array NB is contiguously adjacent the nozzle array NA along the Y-axis. 
     The nozzles  47  of the drop generators are smaller than the ends of the outlet channels  35 , and each nozzle can be selectively positioned within the end of the associated outlet channel. The ends of the outlet channels  35  can be circular or non-circular (e.g., oval or egg-shaped). Generally, the arrangement(s) of the nozzles  47  can be configured by selection of the slant of the columns of drop generators and selective positioning of the nozzles  47  in the end of their respective outlet channels  45 . 
     The nozzles of the nozzle array NA are arranged in a linear array of slanted columnar arrays NAC 1 -NACN which generally correspond to the slanted columnar arrays AC 1 -ACN of the array A of drop generators. The linear array extends along the X-axis, and the slanted columnar arrays of nozzles can be mutually parallel and slanted or oblique relative to the X-axis as well as the Y-axis. Each columnar array of nozzles includes the same number of nozzles, and the columnar arrays of nozzles can be substantially aligned along the Y-axis such that the nozzles  47  form rows NAR 1 -NAR 8  that can be mutually parallel and generally parallel to the X-axis. Eight rows are shown as an illustrative example and it should be appreciated that the number of rows can be appropriately selected. The nozzles of the nozzle array NA can be conveniently referenced by their columnar and row location (e.g., NAC 1 /NAR 1  or NAC 1 / 1 , NAC 1 /NAR 2  or NAC 1 / 2 , etc.). 
     By way of illustrative example, in each columnar array of nozzles, the ink drop generators of the odd numbered rows NAR 1 , NAR 3 , NAR 5 , NAR 7  can be fluidically connected to an associated first finger manifold  161 , while the nozzles of the even numbered rows AR 2 , AR 4 , AR 6 , AR 8  can be connected to an associated second finger manifold  162  that is adjacent to the associated first finger manifold  161 . In other words, the nozzles of each nozzle column NAC 1 -NACN are alternatingly fluidically coupled, row by row, to one of an associated pair of finger manifolds, wherein the associated pair of finger manifolds comprises a first finger manifold  161  and a second finger manifold  162  that is adjacent to the first finger manifold  161 . In this manner, the nozzles of the odd numbered nozzle rows NAR 1 , NAR 3 , NAR 5 , NAR 7  can be fluidically coupled to the first primary manifold  61 , while nozzles of the even numbered nozzle rows NAR 2 , NAR 4 , NAR 6 , NAR 8  can be fluidically coupled to the second primary manifold  62 . Thus, the rows NAR 1 -NAR 8  of nozzles can be alternatingly fluidically coupled, row by row, to the first primary manifold  61  and the second primary manifold  62 . 
     Thus, each slanted columnar array NAC 1 -NACN of nozzles can comprise interleaved substantially parallel, linear odd row and even row sub-columns, wherein the odd row sub-column includes nozzles in the odd numbered rows NAR 1 , NAR 3 , NAR 5 , NAR 7  while the even row sub-column includes nozzles in the even numbered rows NAR 2 , NAR 4 , NAR 6 , NAR 8 . For ease of reference, the nozzles in the odd numbered rows are labeled M, while the nozzles in the even numbered rows are labeled C, for the illustrative example wherein the first primary manifold  61  provides magenta ink and wherein the second primary manifold  62  provides cyan ink. For convenience, each odd row sub-column can be conveniently referred to as an M sub-column, and each even row sub-column can be conveniently referred to as a C sub-column. The interleaved substantially parallel M and C sub-columns of each columnar array NAC 1 -NACN can be non-colinear. In this manner, the nozzles of an M sub-column are fluidically coupled to an associated first finger manifold  161  (and the first primary manifold  61 ), while the nozzles of a C sub-column are fluidically coupled to an associated second finger manifold  162  (and the second primary manifold  62 ), for example. The spacing between nozzles in a sub-column and the angle of the sub-column relative to the Y-axis, for example, determine a nozzle pitch XP along the X-axis for the sub-column. The nozzle pitch XP can be substantially identical for both M and C sub-columns, for example. The angle of a sub-column relative to the Y-axis and the number of nozzles in the sub-column determine the span along the X-axis of the sub-column. By way of illustrative example, the angle of the M sub-columns and the number of nozzles in each M sub-column can be selected so that the nozzles of all the M sub-columns have a substantially uniform pitch XP along the X-axis. Similarly, the angle of the C sub-columns and the number of nozzles in each C sub-column can be selected so that the nozzles of all the C sub-columns have a substantially uniform pitch XP along the X-axis. By way of illustrative example, the M and C sub-columns include the same number of nozzles so that each M and C sub-column has substantially the same uniform pitch along the X-axis. Such substantially uniform nozzle pitch can be at most about 1/75 inches, for example. As another example, the substantially uniform nozzle pitch XP of each of the M and C sub-columns can be at most about 1/37.5 inches. 
     The interleaved M and C sub-columns, each having N nozzles, of a slanted columnar array of nozzles NAC 1 -NACN thus form N pairs of nozzles, wherein each pair includes a nozzle in the M sub-column (and thus in an odd numbered row) and a generally vertically adjacent nozzle in the C sub-column (and thus in an even numbered row), e.g., NAC 1 / 1  and NAC 1 / 2 , NAC 1 / 3  and NAC 1 / 4 , etc. Each sub-column includes a plurality of nozzles and thus N is greater than 1. Such nozzle pairs can be conveniently called odd/even nozzle pairs, and each pair can be conveniently referenced by columnar array and row locations, e.g., NAC 1 / 1 _ 2 , NAC 1 / 3 _ 4 , etc. For the illustrative example wherein the odd row nozzles provide magenta drops and the even row nozzles provide cyan drops, the odd/even nozzle pairs can be conveniently called MC nozzle pairs. The offset between each odd row sub-column and the even row sub-column with which it is interleaved can be selected such that the nozzles of each odd/even nozzle pair are aligned along the X-axis and thus parallel to the Y-axis (non-slanted) or offset along the X-axis and thus non-parallel to the Y-axis (slanted). 
     In this manner, the nozzles of the nozzle array NA can be viewed as being arranged in rows of odd/even nozzle pairs, wherein each odd/even nozzle pair comprises nozzles that are generally adjacent along the Y-axis. 
     The nozzles of the nozzle array NB are arranged in a linear array of slanted columnar arrays NBC 1 -NBCN which generally correspond to the slanted columnar arrays BC 1 -BCN of the array B of drop generators. The linear array extends along the X-axis, and the slanted columnar arrays of nozzles can be mutually parallel and slanted or oblique relative to the X-axis as well as the Y-axis. Each columnar array of nozzles includes the same number of nozzles, and the columnar arrays of nozzles can be substantially aligned along the Y-axis such that the nozzles  47  form rows NBR 1 -NBR 8  that can be mutually parallel and generally parallel to the X-axis. Eight rows are shown as an illustrative example and it should be appreciated that the number of rows can be appropriately selected. The nozzles of the array NB can be conveniently referenced by their columnar and row location (e.g., NBC 1 /NBR 1  or NBC 1 / 1 , NBC 1 /NBR 2  or NBC 1 / 2 , etc.). 
     By way of illustrative example, in each columnar array of nozzles, the ink drop generators of the odd numbered rows NBR 1 , NBR 3 , NBR 5 , NBR 7  can be fluidically connected to an associated third finger manifold  163 , while the nozzles of the even numbered rows NBR 2 , NBR 4 , NBR 6 , NBR 8  can be connected to an associated fourth finger manifold  164  that is adjacent to the associated third finger manifold  163 . In other words, the nozzles of each nozzle column NBC 1 -NBCN are alternatingly fluidically coupled, row by row, to one of an associated pair of finger manifolds, wherein the associated pair of finger manifolds comprises a third finger manifold  163  and a fourth finger manifold  164  that is adjacent to the third finger manifold  163 . In this manner, the nozzles of the odd numbered nozzle rows NBR 1 , NBR 3 , NBR 5 , NBR 7  can be fluidically coupled to the third primary manifold  63 , while nozzles of the even numbered nozzle rows NBR 2 , NBR 4 , NBR 6 , NBR 8  can be fluidically coupled to the fourth primary manifold  64 . Thus, the rows NBR 1 -NBR 8  of nozzles can be alternatingly fluidically coupled, row by row, to the third primary manifold  63  and the fourth primary manifold  64 . 
     Each slanted columnar array NBC 1 -NBCN of nozzles can comprise interleaved substantially parallel, linear odd row and even row sub-columns of nozzles, wherein the odd row sub-column includes nozzles in the odd numbered rows NBR 1 , NBR 3 , NBR 5 , NBR 7  while the even row sub-column includes nozzles in the even numbered rows NBR 2 , NBR 4 , NBR 6 , NBR 8 . For ease of reference, the nozzles in the odd numbered rows are labeled Y, while the nozzles in the even numbered rows are labeled K, for the illustrative example wherein the third primary manifold  63  provides yellow ink and wherein the fourth primary manifold provides black ink. For convenience, each odd row sub-column can be conveniently referred to as a Y sub-column, and each even row sub-column can be conveniently referred to as a K sub-column. The interleaved substantially parallel sub-columns can be non-co-linear. In this manner, the nozzles of the Y sub-column (odd rows) are fluidically coupled to the associated third finger manifold  163  while the nozzles of the K sub-column (even rows) are fluidically coupled to the associated fourth finger manifold  164 , for example. The spacing between nozzles in a sub-column and the angle of the sub-column relative to the Y-axis, for example, determine a nozzle pitch XP along the X-axis for the sub-column. The nozzle pitch XP can be substantially identical for the Y sub-column and the K sub-column, for example. The angle of a sub-column relative to the Y-axis and the number of nozzles in the sub-column determine the span along the X-axis of the sub-column. By way of illustrative example, the angle of the Y sub-columns and the number of nozzles in each Y sub-column can be selected so that the nozzles of all the Y sub-columns have a substantially uniform pitch XP along the X-axis. Similarly, the angle of the K sub-columns and the number of nozzles in each K sub-column can be selected so that the nozzles of all the K sub-columns have a substantially uniformly pitch along the X-axis. By way of illustrative example, the Y and K sub-columns include the same number of nozzles so that each sub-column has substantially the same uniform nozzle pitch along the X-axis. Such substantially uniform nozzle pitch can be at most about 1/75 inches, for example. As another example, the substantially uniform nozzle pitch XP of each of the Y and K sub-columns can be at most about 1/37.5 inches. 
     The interleaved Y and K sub-columns, each having N nozzles, of a slanted columnar array of nozzles NB 1 -NBN thus form N pairs of nozzles, wherein each pair includes a nozzle in the Y sub-column (and thus in an odd numbered row) and a generally vertically adjacent nozzle in the K sub-column (and thus in an even numbered row), e.g., NBC 1 / 1  and NBC 1 / 2 , NBC 1 / 3  and NBC 1 / 4 , etc. Such nozzle pairs can be conveniently called odd/even nozzle pairs, and each pair can be conveniently referenced by columnar array and row locations, e.g., NBC 1 / 1 _ 2 , NBC 1 / 3 _ 4 , etc. For the illustrative example wherein the odd row nozzles provide yellow drops and the even row nozzles provide black drops, the odd/even nozzle pairs can be conveniently called YK nozzle pairs. The offset between each odd row sub-column and the even row sub-column with which it is interleaved can be selected such that the nozzles of each odd/even nozzle pair are aligned along the X-axis and thus parallel to the Y-axis (non-slanted) or offset along the X-axis and thus non-parallel to the Y-axis (slanted). 
     In this manner, the nozzles of the nozzle array NB can be viewed as being arranged in rows of nozzle pairs, wherein each nozzle pair comprises nozzles that are generally adjacent along the Y-axis. 
     Each of the columnar arrays of the nozzle arrays NA, NB can have the same number of nozzles, the same number of columnar arrays NAC 1 -NACN, NBC 1 -NBCN, the same number of nozzles in each of the nozzle sub-columns, and the same number of odd/even nozzle pairs in each columnar array. The arrangement of nozzles in the array NA can be the same as the nozzle arrangement in the array NB, or it can be different, for example as described below. 
     The nozzle arrays NA, NB are contiguously adjacent along the Y-axis and can be relatively positioned along the X-axis such that each columnar array NAC 1 -NACN of the nozzle array NA has a respectively associated columnar array NBC 1 -NBCN of the nozzle array NA generally displaced therefrom along the Y-axis, and such that each odd/even nozzle pair NAC 1 / 1 _ 2 -NACN/ 7 _ 8  of the array NA has a respectively associated odd/even pair NBC 1 / 1 _ 2 -NBCN/ 7 _ 8  of the array NB. Associated columnar arrays NAC 1 /NBC 1 -NACN/NBCN can be aligned along the X-axis, or they can be offset along the X-axis, for example. 
     By way of illustrative example, the nozzles of each odd/even nozzle pair in the columnar arrays of the nozzle arrays NA, NB can be aligned along the X-axis, as schematically illustrated for the array NA and the array NB in  FIGS. 12 and 13 . An odd/even nozzle pair having nozzles that are aligned along the X-axis can be conveniently called a non-offset or non-slanted nozzle pair. Each non-slanted nozzle pair in the nozzle array NB can be aligned along the X-axis with an associated non-slanted nozzle pair in the nozzle array NA, as schematically illustrated in  FIG. 12 . In another embodiment, each non-slanted nozzle pair in the nozzle array NB can be offset along the X-axis relative to an associated non-slanted nozzle pair in the nozzle array NA, as schematically illustrated in  FIG. 13 . The offset between associated non-slanted nozzle pairs can be greater than zero inches and at most about 0.005 inches, for example. As another example, the offset can be greater than zero inches and at most about ⅓ times the sub-column nozzle pitch XP along the X-axis (i.e., XP/3). 
     By way of illustrative example, the nozzles of each odd/even nozzle pair in the columnar arrays of both of the nozzle arrays NA, NB can be offset along the X-axis, as schematically illustrated for the nozzle arrays NA and NB in  FIGS. 14 and 15 . An odd/even nozzle pair having nozzles that are offset along the X-axis can be conveniently called an offset or slanted nozzle pair. The offset along the X-axis between the nozzles of an offset or slanted nozzle pair can be greater than zero inches and no greater than about 0.005 inches, for example. As another example, the offset between the nozzles of a slanted nozzle pair can be at greater than zero inches and at most about ⅓ times the sub-column nozzle pitch XP along the X-axis (i.e. XP/3). Each slanted nozzle pair in the nozzle array NB can be aligned along the X-axis with an associated slanted nozzle pair in the nozzle array NA, as schematically illustrated in  FIG. 14 . In another embodiment, each slanted nozzle pair in the nozzle array NB can be offset along the X-axis relative to an associated slanted nozzle pair in the nozzle array NA, as schematically illustrated in  FIG. 13 . By way of specific example, the even row nozzles of associated slanted nozzle pairs (e.g., C and K) can be aligned along the X-axis so as to be parallel to the Y-axis. The odd row nozzles of associated slanted nozzle (e.g., M and Y) can be on either side of the even row nozzles along the X-axis. The offset along the X-axis between associated slanted nozzle pairs can be greater than zero inches and at most about 0.005 inches. As another example, such offset can be greater than zero and at most about ⅓ times the sub-column nozzle pitch XP along the X-axis. 
     By way of illustrative example, the odd/even nozzle pairs of the nozzle array NA can be non-slanted and the odd/even nozzle pairs of the nozzle array NB can be slanted, as schematically illustrated in  FIG. 16 . For example, one of a slanted nozzle pair of the nozzle array NB can be aligned along the X-axis with the associated non-slanted nozzle pair of the nozzle array NB. By way of specific example, each odd row nozzle of a slanted nozzle pair of the nozzle array NB (e.g., Y) can be aligned along the X-axis with the associated non-slanted nozzle pair of the nozzle array NA (e.g., M and C), such that the even row nozzle of such slanted nozzle pair (e.g., K) is offset along the X-axis relative to its associated odd row nozzle and the associated non-slanted nozzle pair of the nozzle array NA, for example as schematically depicted in  FIG. 16 . The amount of offset of the non-aligned nozzle can be greater than zero inches and at most about 0.005 inches, for example. As another example, the amount of offset of the non-aligned nozzle can be greater than zero inches and at most about ⅓ times the sub-column nozzle pitch XP along the X-axis. 
     The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.