Patent Publication Number: US-2022227131-A1

Title: Nozzle arrangements and supply channels

Description:
BACKGROUND 
     Fluid ejection dies may eject fluid drops via nozzles thereof. Such fluid ejection dies may include fluid actuators that may be actuated to thereby cause ejection of drops of fluid through nozzle orifices of the nozzles. Some example fluid ejection dies may be printheads, where the fluid ejected may correspond to ink. 
    
    
     
       DRAWINGS 
         FIG. 1  is a schematic view that illustrates some components of an example fluid ejection die. 
         FIG. 2  is a schematic view that illustrates some components of an example fluid ejection die. 
         FIG. 3  is a schematic view that illustrates some components of an example fluid ejection die. 
         FIGS. 4A-E  are schematic views that illustrate some components of an example fluid ejection die. 
         FIGS. 5A-C  are schematic views that illustrate some components of an example fluid ejection die. 
         FIG. 6  is a schematic view that illustrates some components of an example fluid ejection die. 
         FIG. 7  is a schematic view that illustrates some components of an example fluid ejection die. 
         FIG. 8  is a block diagram that illustrates some components of an example fluid ejection die. 
         FIG. 9  is a block diagram that illustrates some components of an example fluid ejection device. 
         FIGS. 10A-B  are block diagrams that illustrate some components of an example fluid ejection die. 
         FIG. 11  is a schematic view that illustrates some components of an example fluid ejection device. 
     
    
    
     Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The figures are not necessarily to scale, and the size of some parts may be exaggerated to more clearly illustrate the example shown. Moreover, the drawings provide examples and/or implementations consistent with the description; however, the description is not limited to the examples and/or implementations provided in the drawings. 
     DESCRIPTION 
     Examples of fluid ejection dies may comprise nozzles that may be distributed across a length and width of the die. In an example fluid ejection die, each nozzle may be fluidically coupled to an ejection chamber, and a fluid actuator may be disposed in the ejection chamber. Examples may include at least one fluid feed hole fluidically coupled to each ejection chamber and nozzle. Fluid may be conveyed through the at least one fluid feed hole to the ejection chamber for ejection via the nozzle. Description provided herein may describe examples as having nozzles, ejection chambers, fluid feed holes, fluid supply channels, and/or other such fluidic structures. Such fluidic structures may be formed by removing material from a substrate or other material layers. 
     Examples provided herein may be formed by performing various microfabrication and/or micromachining processes on a substrate and layers of material to form and/or connect structures and/or components. The substrate may comprise a silicon based wafer or other such similar materials used for microfabricated devices (e.g., glass, gallium arsenide, plastics, etc.). Examples may comprise microfluidic channels, fluid feed holes, fluid actuators, and/or volumetric chambers. Microfluidic channels, holes, and/or chambers may be formed by performing etching, microfabrication processes (e.g., photolithography), or micromachining processes in a substrate. Accordingly, microfluidic channels, feed holes, and/or chambers may be defined by surfaces fabricated in the substrate of a microfluidic device. 
     Moreover, material layers may be formed on substrate layers, and microfabrication and/or micromachining processes may be performed thereon to form fluid structures and/or components. An example of a material layers may include, for example, a photoresist layer, in which openings, such as nozzles may be formed. In addition, various structures and corresponding volumes defined thereby may be formed from substrate bonding or other similar processes. 
     In example fluid ejection dies, nozzles may be arranged across a length of a fluid ejection die and across a width of the fluid ejection die. In examples described herein a set of neighboring nozzles may refer to at least two nozzles having proximate positions along the die length. In addition, a respective pair of neighboring nozzles and a neighboring nozzle pair may also refer to two nozzles having proximate positions along the die length. In examples contemplated herein, at least one respective pair of neighboring nozzles of a fluid ejection die may be positioned at different positions along the width of the fluid ejection die. Accordingly, at least some nozzles having sequential nozzle positions (which corresponds to the position of the nozzle with respect to the length of the die) may be spaced apart along the width of the fluid ejection die. 
     Furthermore, fluid ejection dies described herein may comprise arrangements of nozzles such that the fluid ejection die comprises approximately 2000 to approximately 6000 nozzles on the die. In some examples all nozzles of the die may be coupled to a single fluid source. For example, in an example fluid ejection die in the form of a printhead according to the description provided herein, the printhead may comprise more than 2000 nozzles, where all the nozzles of the die may correspond to a single printing fluid, such as a single ink color. In other examples, a first set of nozzles of a die may be coupled to a first fluid source, and a second set of nozzles of a die may be coupled to a second fluid source. For example, in a printhead, the die may comprise at least 2000 nozzles coupled to a first ink color fluid source, and the die may comprise at least 2000 nozzles coupled to a second ink color fluid source. In these examples, nozzles of the die may be arranged in a distributed manner across a length and a width of the die. For example, nozzles of the die may be arranged such that a minimum distance between nozzles of the die is approximately 100 micrometers (μm). 
     As described above, for each nozzle, the fluid ejection die may include a fluid ejector, where the fluid ejector may include a piezoelectric membrane based actuator, a thermal resistor based actuator, an electrostatic membrane actuator, a mechanical/impact driven membrane actuator, a magneto-strictive drive actuator, or other such elements that may cause displacement of fluid responsive to electrical actuation. 
     In some fluid ejection dies, ejection of fluid drops from arrangements of nozzles can relate to air flow patterns in a drop ejection area. Some arrangements of nozzles may result in air flow patterns that influence travel of ejected drops in a drop ejection area. Some air flow patterns generated by fluid drop ejection of fluid ejection dies may result in reduced drop trajectory and/or drop placement accuracy. Furthermore, some air flow patterns generated by fluid drop ejection of fluid ejection dies may disperse particles in a drop ejection area that may collect on fluid ejection dies. Accordingly, example fluid ejection dies described herein may distribute nozzles across the length and the width of the die to control air flow patterns. Some examples described herein may reduce air flow generation related to fluid drop ejection based at least in part on nozzle arrangements of the fluid ejection die. Some example fluid ejection dies may reduce air disturbance of ejected fluid drops due to ejection of other fluid drops from proximate nozzles based at least in part on nozzle arrangements described herein. Nozzle arrangements described herein may correspond to distances between nozzles, distances between nozzle columns, angles of orientations between nozzles, densities of nozzles per square unit of surface area of a fluid ejection die, number of nozzles per unit of distance corresponding to a length of a die, or any combination thereof. 
     Turning now to the figures, and particularly to  FIG. 1 , this figure illustrates an example fluid ejection die  10 . As shown, the fluid ejection die  10  may comprise a plurality of nozzles  12   a - x  arranged along a die length  14  and a die width  16 . As used herein, neighboring nozzles may be used to describe respective nozzles  12   a - x  having proximate positions along the length of the die  14 . For example, a first nozzle  12   a , which may be described as having a first nozzle position, may be a neighboring nozzle of a second nozzle  12   b , which may be described as having a second nozzle position. The first nozzle  12   a  and the second nozzle  12   b  may further be described as a neighboring nozzle pair or a pair of neighboring nozzles. In the example die  10  of  FIG. 1 , the nozzles  12   a - x  may be described as corresponding to a respective nozzle position based on the positioning of the nozzle  12   a  with respect to the length of the die  14 . Accordingly, in this example, the die  10  includes the first nozzle  12   a  in a first nozzle position, the second nozzle  12   b  in a second nozzle position, with likewise nozzle location designations for third through 24th nozzle positions  12   c - 12   x  respectively. 
     In addition, in this example, sets of neighboring nozzles and neighboring nozzle sets may be used to refer to groups of nozzles having proximate locations along the length  14  of the die  10 , i.e., sets of neighboring nozzles may include at least two nozzles  12   a - x  having sequential nozzle positions. For example, the first nozzle  12   a , the second nozzle  12   b , and the third nozzle  12   c  may be considered a set of neighboring nozzles. Similarly, the first nozzle  12   a , the second nozzle  12   b , the third nozzle  12   c , and the fourth nozzle  12   d  may be considered a set of neighboring nozzles. 
     Accordingly, in the example of  FIG. 1 , the nozzles  12   a - x  include at least one respective pair of neighboring nozzles that are positioned at different die width positions along the width of the fluid ejection die. To illustrate by way of example, the first nozzle  12   a  and second nozzle  12   b  are a respective pair of neighboring nozzles, and the first nozzle  12   a  and second nozzle  12   b  are positioned at different positions along the width  16  of the die. Similarly, the second nozzle  12   b  and the third nozzle  12   c  are a respective pair of neighboring nozzles, and the second nozzle  12   b  and the third nozzle  12   c  are positioned at different die width positions along the width  16  of the die. Moreover, in this example, the first nozzle  12   a , the second nozzle  12   b , the third nozzle  12   c , and a fourth nozzle  12   d  are a set of neighboring nozzles, and at least one nozzle of the respective set of neighboring nozzles  12   a - d  is positioned at a different die width  16  position. Notably, in this example, each nozzle  12   a - d  of the respective set of neighboring nozzles  12   a - d  is positioned at a different die width  16  position. Therefore, as shown in  FIG. 1 , the nozzles  12   a - x  of the fluid ejection die  10  are arranged such that, for pairs and sets of neighboring nozzles, at least one respective nozzle of each set of neighboring nozzles is positioned at different die width  16  positions. 
     Furthermore, it will be noted that the fluid ejection die  10  example of  FIG. 1  includes at least one nozzle  12   a - x  per nozzle position. Accordingly, it may be appreciated that the nozzles  12   a - x  of the fluid ejection die may be fluidically coupled to a single fluid source. For example, if the fluid ejection die  10  corresponds to a printhead, the nozzles  12   a - x  may all couple to a single fluid print material source of a single color. As another example, if the fluid ejection die  10  corresponds to a printhead for an additive manufacturing system, the nozzles  12   a - x  may be fluidically coupled to a single 3D print material source, such as a fluid bonding agent, a fluid detailing agent, a fluid surface treatment material, etc. Nozzles coupled to a single fluid source may be described as being fluidically coupled together. 
     In the example shown in  FIG. 1 , the fluid ejection die  10  includes the nozzles  12   a - x  arranged in nozzle columns  20   a - d . As shown, a first nozzle column  20   a  of the example includes the first nozzle  12   a , the fifth nozzle  12   e , the ninth nozzle  12   i , the 13th nozzle  12   m , the 17th nozzle  12   q , and the 21st nozzle  12   u . A second nozzle column  20   b  of the example includes the second nozzle  12   b , the sixth nozzle  12   f , the 10th nozzle  12   j , the 14th nozzle  12   n , the 18th nozzle  12   r , and the 22nd nozzle  12   v . A third nozzle column  20   c  of the example includes the third nozzle  12   c , the seventh nozzle  12   g , the 11th nozzle  12   k , the 15th nozzle  12   o , the 19th nozzle  12   s , and the 23rd nozzle  12   w . A fourth nozzle column  20   d  of the example includes the fourth nozzle  12   d , the eighth nozzle  12   h , the 12th nozzle  12   l , the 16th nozzle  12   p , the 20th nozzle  12   t , and the 24th nozzle  12   x.    
     As shown, neighboring nozzles are distributed across the width of the die  16  in different nozzle columns  20   a - d . Moreover, the nozzles  12   a - x  of each nozzle column  20   a - d  are offset along the die length  14  and the die width  16 , such that respective nozzles of each nozzle column  20   a - d  have an oblique angle of orientation with neighboring nozzles  12   a - x . An example angle of orientation  22  between neighboring nozzles is illustrated between the sixth nozzle  12   f  and the seventh nozzle  12   g  in  FIG. 1 . Accordingly, neighboring nozzles located in the different nozzle columns  20   a - d  may be arranged along a diagonal  24  with respect to the die length  14  and the die width  16 . As may be noted, the diagonal  24  may correspond to the angle of orientation  22  between neighboring nozzles. Furthermore, it may be noted that in some examples, a size of a set of neighboring nozzles may correspond to the number of nozzle columns. In the example of  FIG. 1 , the size of the set of neighboring nozzles may be four nozzles, and the number of nozzle columns  20   a - d  may also be four. Accordingly, for a set of four neighboring nozzles, each respective nozzle of the set may be arranged in a different respective nozzle column  20   a - d.    
     Furthermore, the example of  FIG. 1  illustrates example arrangements of the nozzles  12   a - x  that may be implemented in other examples. As shown in  FIG. 1 , nozzles  12   a - x  of a respective nozzle column  20   a - d  may be arranged such that a nozzle-to-nozzle distance between at least some nozzles  12   a - x  of the respective nozzle column  20   a - d  may be at least 100 micrometers (μm). In some examples, a nozzle-to-nozzle distance  24  for at least some nozzles of a respective nozzle column  20   a - d  may be within a range of approximately 100 μm to approximately 400 μm. In the example of  FIG. 1 , proximate nozzles  12   a - x  of a respective nozzle column  20   a - d  may be referred to as sequential nozzles  12   a - x  of the respective nozzle column  20   a - d . To illustrate by way of example, the first nozzle  12   a  and the fifth nozzle  12   e  may be referred to as sequential nozzles of the respective first nozzle column  20   a . Similarly, the second nozzle  12   b  and the sixth nozzle  12   f  may be referred to as sequential nozzles of the respective second nozzle column  20   b . Therefore, the nozzle-to-nozzle distance  24  for nozzles  12   a - x  of a respective column  20   a - d  may refer to the distance between sequential nozzles  12   a - x  of the respective column  20   a - d.    
     Likewise, the example of  FIG. 1  also illustrates an arrangement of nozzle columns that may be implemented in other examples. As shown, a distance between nozzle columns  26  (which may be referred to as a nozzle column to nozzle column distance) may be at least approximately 100 μm. In some examples, the distance between nozzle columns  26  may be within a range of approximately 100 μm to approximately 400 μm. 
     In  FIG. 1 , a cross sectional view  30  along line A-A is provided. As shown in this example, for each respective nozzle (the example cross-sectional view  30  is provided for the 16th nozzle  12   p ), the fluid ejection die  10  further includes a fluid ejection chamber  32  arranged proximate to and fluidically coupled with the nozzle  12   p . The die  10  further includes at least one fluid feed hole  34  fluidically coupled to the fluid ejection chamber  32 . Accordingly, in examples contemplated herein, fluid may flow through the fluid feed hole  34  to the fluid ejection chamber  32 , and fluid may be ejected from the fluid ejection chamber  32  through the nozzle  12   p . As illustrated by the cross-sectional view  30 , the fluid ejection die  10  may comprise an array of fluid feed holes  34  formed through a surface opposite the surface through which the nozzle  12   p  is formed. 
     As may be appreciated with respect to  FIG. 1 , the quantity of nozzles shown is for clarity. Examples of fluid ejection dies may comprise more nozzles in more or less nozzle columns. In some example fluid ejection dies, the die may comprise approximately 2000 to approximately 6000 nozzles. In addition, some example nozzle columns of such example fluid ejection dies may comprise at approximately 40 to approximately 300 nozzles per column. 
     Furthermore, in some examples spacing between nozzles of a respective nozzle column (e.g., the distance between the first nozzle  12   a  and the fifth nozzle  12   e  of  FIG. 1 ) may be approximately 50 μm to approximately 500 μm. In other examples, the spacing between nozzles of a respective nozzle column may be at least 100 μm. Similarly, in some examples a spacing between nozzle columns (e.g., the distance between the first nozzle column  20   a  and the second nozzle column  20   b  in  FIG. 1 ) may be approximately 50 μm to approximately 500 μm. In some examples, the spacing between nozzle columns may be at least 100 μm. 
     Moreover, as shown in  FIG. 1 , nozzle columns may be arranged in an offset manner such that, for a set of nozzle columns, at least one nozzle is located at each respective nozzle position (where the nozzle position corresponds to a position along the length of the die). Therefore, it will be appreciated that, in such examples, the angle of orientation (e.g., the angle of orientation  22  shown in  FIG. 1 ) between neighboring nozzles may be such that nozzles of different nozzle columns are arranged in unique nozzle positions. In other words, the diagonal arrangement of nozzles across the length and width of the die are such that nozzles of different nozzle columns are neighboring nozzles and nozzles of different nozzle columns are not positioned at common nozzle positions. In some examples, an angle of orientation between neighboring nozzles may be approximately 10° to approximately 45°. In some examples, an angle of orientation between neighboring nozzles may be at least 20°. In other examples, an angle of orientation may be less than approximately 75°. Furthermore, nozzles of a respective nozzle column may be offset with regard to the width of the die to adjust for drop ejection timing. Accordingly, while examples illustrated herein may illustrate aligned diagonals and columns of nozzles, other examples may include columnar nozzles having offsets along the width of the die. In some examples, nozzles of a respective column may be offset with respect along the width by approximately 5 μm to approximately 30 μm. 
     Accordingly, the spacing between nozzles, the spacing between nozzle columns, and the angle of orientation between neighboring nozzles may be defined such that nozzle columns are arranged in a staggered and offset manner across the die. In such examples, the spacing between nozzles, the spacing between nozzle columns, and/or the angle of orientation between neighboring nozzles may facilitate ejection of fluid drops via such nozzles that controls generated air flow associated with such ejections. 
     In some examples, columns of nozzles may be spaced apart across the width of the die, and the columns of nozzles may be staggered and/or off-set along the length of the die. In some examples, at least some nozzles of different nozzle columns may be staggered according to an angle of orientation. The arrangement of nozzles  12   a - x  and nozzle columns  20   a - d  may be referred to as staggered nozzle columns. Accordingly, examples contemplated herein may include at least four staggered nozzle columns. 
       FIG. 2  provides an example fluid ejection die  50 . As shown, the die  50  includes a plurality of nozzles  52   a - x  arranged along the die length  54  and the die width  56 . As discussed previously, a nozzle position corresponds to a position along the die length  54 , and in this example, the die  50  includes a first nozzle  52   a  at a first nozzle position through a 24th nozzle  52   x  at a 24th nozzle position. The nozzles  52   a - x  of the example die  50  are arranged such that, for a set of neighboring nozzles (i.e., nozzles having sequential nozzle positions), at least a subset of the set of neighboring nozzles are positioned at different positions along the width of the die  56 . For example, the first nozzle  52   a  (at the first nozzle position) and a second nozzle  52   b  (at the second nozzle position) may be considered a set of neighboring nozzles. As shown, the first nozzle  52   a  and the second nozzle  52   b  are spaced apart with respect to the die width  56 —i.e., the first nozzle  52   a  and the second nozzle  52   b  are positioned at different die width positions along the width of the fluid ejection die  50 . 
     In the example die  50  of  FIG. 2 , the nozzles  52   a - x  are arranged in a first nozzle column  60   a  and a second nozzle column  60   b . In this example, the fluid ejection die  50  further includes an array of ribs  64   a ,  64   b  (illustrated in dashed line) formed on a back surface of the die  50 . As shown, the array of ribs  64   a ,  64   b  are aligned with the nozzle columns  60   a ,  60   b  for the example die  50 . A cross-sectional view  70  along line B-B provides further detail regarding the arrangement of the ribs  64   a ,  64   b  and further features of the fluid ejection die  50 . For each respective nozzle  52   a - x  (in the example cross-sectional view, the 16th nozzle  52   p  is illustrated), the fluid ejection die  50  further includes a respective first fluid feed hole  72   a  and a respective second fluid feed hole  72   b  fluidically coupled to a respective fluid ejection chamber  74 . Each respective fluid ejection chamber  74  is further fluidically coupled to the respective nozzle  52   p.    
     As shown, the fluid ejection chamber  74  is arranged over a respective rib  64   b  of the array of ribs such that the first fluid feedhole  72   a  is positioned on a first side of the respective rib  64   b  and the second fluid feedhole  72   b  is positioned on a second side of the respective rib  64   b . The array of ribs  64   a ,  64   b  may form fluid circulation channels  80 ,  82  across the die  50 . Accordingly, fluid may be input from a respective first fluid circulation channel  80  via the respective first fluid feed hole  72   a  into the respective fluid ejection chamber  74 . Fluid may be output from the respective fluid ejection chamber  74  to a respective second fluid circulation channel  82  via the respective second fluid feed hole  72   b . This example flow of fluid, which may be referred to as microrecirculation is illustrated in  FIG. 2  in dashed line. While not shown, it may be appreciated that, fluid may also be output from the respective fluid ejection chamber as fluid drops via the respective nozzle  52   p.    
     As shown in the cross-sectional view  70  of  FIG. 2 , for each respective nozzle  52   p , the die  50  may further comprise a respective first fluid actuator  90  disposed in the respective fluid ejection chamber  74 . Actuation of the respective first fluid actuator  90  may cause ejection of a drop of fluid from the respective fluid ejection chamber  74 . In some examples, the first fluid actuator  90  may be a thermal resistor based fluid actuator, which may be referred to as a thermal fluid actuator. The die  50  may further include a respective second fluid actuator  92 . Actuation of the respective second fluid actuator  92  may cause flow of fluid from the respective fluid ejection chamber  74  into the respective second fluid circulation channel  82 . Accordingly, while the nozzles  52   a - x  may be fluidically coupled together for a fluid source, the ribs  64   a - b  may fluidically separate the fluid input to the ejection chambers  74  and the fluid output from the ejection chambers  74 . 
     While not illustrated in the example cross-sectional view  70 , it may be appreciated that the respective first fluid circulation channel  80 , surfaces of which may be defined by the first rib  64   a  and second rib  64   b  of the array of ribs, may also be fluidically coupled to respective first fluid feed holes for all respective fluid ejection chambers of the die  50 . Accordingly, the respective first fluid circulation channel  80  may be a fluid input supply for the nozzles  52   a - x  of the die  50 . Fluid circulated through the fluid ejection chambers  74  (e.g., the example flow illustrated in the cross-sectional view  70 ) may be fluidically separated from the respective first fluid circulation channel  80 , and therefore fluidically separated from the fluid input supply to the respective ejection chambers  74  via the first rib  64   a  and the second rib  64   b.    
       FIG. 3  provides a block diagram of an example fluid ejection die  100 . In this example, the die  100  comprises a plurality of nozzles  102   a - x  arranged along a die length  104  and a die width  106 . In particular, the nozzles  102   a - x  are arranged such that one nozzle  102   a - x  is positioned at each die length  104  position and neighboring nozzles (e.g., a first nozzle  102   a , a second nozzle  102   b , a third nozzle  102   c ; or a fourth nozzle  102   d  and a fifth nozzle  102   e ) are positioned at different die width  106  positions. In this example, the nozzles  102   a - x  are arranged in four nozzle columns  110   a - d.    
     Furthermore, the fluid ejection die  100  of  FIG. 3  includes an array of ribs  112   a ,  112   b . In fluid die examples such as the example die  100  of  FIG. 3 , orifices of each nozzle  102   a - x  may be formed on a front surface of the fluid ejection die  100 . The array of ribs  112   a ,  112   b  may be disposed on an opposite, back surface, of the fluid ejection die  100 . As discussed previously, the array of ribs  112   a ,  112   b  may form fluid circulation channels  114 ,  116   a,b  through the fluid ejection die  100 . For each nozzle  102   a - x , the fluid ejection die  100  may further include a respective first fluid feed hole  120   a - x  and a respective second fluid feed hole  122   a - x . In this example, the each first fluid feed hole  120   a - x  may be fluidically coupled to a first fluid circulation channel  114  of the array of fluid circulation channels  114 ,  116   a, b . Similarly, each second fluid feed hole  122   a - x  may be fluidically coupled to second fluid circulation channels  116   a, b . Accordingly, in this example, the fluid ejection die comprises an array of fluid feed holes  120   a - x ,  122   a - x  formed through a surface of the die  100  that is opposite the surface through which the nozzles  102   a - x  are formed. In this example, the fluid ejection die  100  comprises two fluid feed holes  120   a - x ,  122   a - x  for each respective ejection chamber and nozzle  102   a - x . Moreover, as shown, the array of fluid feed holes  120   a - x ,  122   a - x  may be formed through a surface of the die  100  that also engages the ribs  112   a - b . Notably, the nozzles  102   a - x  may be formed through a top surface of the die  100 , and the fluid feed holes  122   a - x  may be formed through a bottom surface of the die  100  that my be adjacent the ribs  112   a - b , and the bottom surface may define an interior surface of the fluid channels  114 ,  116   a - b.    
     While not shown in this example for clarity, the fluidic die  100  may include a respective fluid ejection chamber disposed under each respective nozzle  102   a - x , and the fluid ejection die  100  may further include at least one respective fluid actuator disposed in each respective fluid ejection chamber. As shown in this example, each nozzle  102   a - x  (and the respective fluid ejection chamber disposed thereunder) may be fluidically coupled to the respective first fluid feed hole  120   a - x  and the respective second fluid feedhole  122   a - x  by a respective microfluidic channel  128 . 
     As may be appreciated, in this example, each respective first fluid feed hole  120   a - x  may be a fluid input, where fresh fluid may be sourced from the first fluid circulation channel  114 . Likewise, each respective second fluid feedhole may be a fluid outlet, where fluid may be conveyed to the second fluid circulation channels  116   a - b  when the fluid is not ejected via the nozzles  102   a - x . Accordingly, in some examples, fluid may be input into a respective ejection chamber associated with a respective nozzle  102   a - x  via the respective first fluid feedhole  120   a - x  and the respective microfluidic channel  128  from the first fluid circulation channel  114 . Fluid drops may be ejected from the respective ejection chamber by actuation of at least one fluid actuator disposed in the respective ejection chamber through the respective nozzle  102   a - x . Fluid may also be conveyed (i.e., output) from the respective fluid ejection chamber through the microfluidic channel  128  and the respective second fluid feed hole  122   a - x  to the second fluid circulation channels  116   a - b . While not included in this example, similar to the example of  FIG. 2 , the fluid ejection die  100  may include at least one fluid actuator disposed in each microfluidic channel  128  that may be actuated to facilitate microrecirculation through each fluid ejection chamber. In some examples, the at least one fluid actuator may be disposed proximate the respective first fluid feedhole to pump fluid into the ejection chamber. In some examples, the at least one fluid actuator may be disposed proximate the respective second fluid feedhole to pump fluid from the ejection chamber. 
     Conveying fluid from a fluid input through an ejection chamber and to a fluid output may be referred to as microrecirculation. In some example fluid ejection dies and fluid ejection devices similar to the examples described herein, fluids used therein may include solids suspended in liquid carriers. Microrecirculation of such fluids may reduce settling of such solids in the liquid carriers in the fluid ejection chambers. As an example, a printhead according to may use fluid printing material, such as ink, liquid toner, 3D printer agent, or other such materials. In such example printheads, the aspects of the fluid circulation channels, array of ribs, and microrecirculation channels may be implemented to facilitate movement of the fluid printing material throughout the fluidic architecture of the printhead to thereby maintain suspension of solids in a liquid carrier of the printing material. 
     Turning now to  FIGS. 4A-E , these figures provide portions of example fluid ejection dies having various example nozzle arrangements in which nozzles are arranged across and length and the width of the die such that, for each set of neighboring nozzles, a respective subset of each set of neighboring nozzles are positioned at different die width positions along the width of the die. Furthermore, it may be noted that, in these examples, for a respective fluid input, a single nozzle may be positioned at each nozzle position. 
     In  FIG. 4A , an example fluid ejection die  200  is illustrated. As shown, the nozzles  202   a - x  are arranged along a length and a width of the die. In this example, the nozzles  202   a - x  are arranged in eight nozzle columns.  204   a - h . In this example, a first nozzle column  204   a  may include a first nozzle  202   a , a ninth nozzle  202   i , and a 17th nozzle  202   q . The second nozzle column  204   b  may include a sixth nozzle  202   f , a 14th nozzle  202   n , and a 22nd nozzle  202   v . The third nozzle column  204   c  may include a third nozzle  202   c , an 11th nozzle  202   k , and a 19th nozzle  202   s . The fourth nozzle column  204   d  may include an eighth nozzle  202   h , a 16th nozzle  202   p , and a 24th nozzle  202   x . The fifth nozzle column  204   e  may include a fifth nozzle  202   e , a 13th nozzle  202   m , and a 21st nozzle  202   u . The sixth nozzle column  204   f  may include a second nozzle  202   b , a 10th nozzle  202   j , and an 18th nozzle  202   r . The seventh nozzle column  204   g  may include a seventh nozzle  202   g , a 15th nozzle  202   o , and 23rd nozzle  202   w . The eighth nozzle column  204   g  may include a fourth nozzle  202   d , a 12th nozzle  202   l , and a 20th nozzle  202   t.    
     In this example, the designation of the first nozzle  202   a , second nozzle  202   b , etc. refers to the position of the nozzle along the length of the die  200 , which may be referred to as the nozzle position. Notably, as shown in  FIG. 4A , at least one nozzle is positioned at each nozzle position along the width of the  200 . Accordingly, to perform fluid drop ejection of a fluid for each nozzle position along the width of the die  200 , all nozzles  202   a - x  of this example may be fluidically coupled with the other nozzles  202   a - x.    
     In addition, in this example, the nozzle columns  204   a - h  may be arranged such that a distance between nozzle columns may not be common. As shown, the first nozzle column  204   a  and the second nozzle column  204   b  may be spaced apart by a first distance  206   a . The second nozzle column  204   a  and the third nozzle column  204   c  may be spaced apart by a second distance  206   b  that is different than the first distance  206   a . Other nozzle columns  204   c - h  may be arranged similarly. For example, the spacing between the third nozzle column  204   c  and the fourth nozzle column  204   d  may be the first distance  206   a , and the spacing between the fourth nozzle column and the fifth nozzle column  204   e  may be the second distance  206   b.    
       FIG. 4B  illustrates an example fluid ejection die  250  having a plurality of nozzles  252   a - x  arranged along a length and a width of the die  250  in four nozzle columns  254   a - d . Furthermore, in  FIG. 4B , it may be noted that the nozzles  252   a - x  may be arranged such that some neighboring nozzles may have different angles of orientation therebetween. For example, referring to a ninth nozzle  252   i , a 10th nozzle  252   j , and an 11th nozzle  252   k  of the example, as shown, the ninth nozzle  252   i  and the 10th nozzle  252   j  may be arranged along the length and width of the die  250  at a first angle of orientation  256 . And the 10th nozzle  252   j  and the 11th nozzle  252   k  may be arranged along the length and the width of the die at a second angle of orientation  258  that is different than the first angle of orientation  256 . 
       FIG. 4C  illustrates an example fluid ejection die  270  having a plurality of nozzles  272   a - x  arranged along a length and a width of the fluid ejection die  270  in two nozzle columns  274   a ,  274   b . As shown in  FIG. 4C , in some examples, nozzles  272   a - x  of a respective nozzle column  274   a ,  274   b  may be spaced apart at different distances. To illustrate by way of example, and referring to  FIG. 4C , a first distance  276   a  between a ninth nozzle  272   i  and a 10th nozzle  272   j  of a first nozzle column  274   a  of the die  270  may be different than a second distance  276   b  between a second nozzle  272   b  and a fifth nozzle  272   e  that are in the first nozzle column  274   a . Nozzles of a common nozzle column may be referred to as columnar nozzles. Nozzles proximate each other in a nozzle column may be referred to as sequential columnar nozzles. For example, the first nozzle  272   a  and the second nozzle  272   b  may be referred to as sequential columnar nozzles. Similarly, the second nozzle  272   b  and the fifth nozzle  272   e  may be considered sequential columnar nozzles. Furthermore, the ninth nozzle  272   i  and the 10th nozzle  272   j  may be referred to as sequential columnar nozzles. Returning to the example above, the first distance  276   a  between the sequential columnar nozzles  272   i ,  272  may be less than 50 μm, and the second distance  276   b  between the sequential columnar nozzles  272   b ,  272   e  may be at least 100 μm. As another example, the first distance may be less than 25 μm and the second distance  276   b  may be approximately 100 μm to approximately 400 μm. Furthermore, while not labeled in  FIG. 4C , it may be noted that angles of orientations between neighboring nozzles may be different for the nozzles  272   a - x  of the example die  270 . For example, some neighboring nozzle pairs may be arranged at an angle of orientation that is approximately orthogonal (e.g., the angle of orientation between the first nozzle  272   a  and the second nozzle  272   b ). Other neighboring nozzle pairs may be arranged at an angle of orientation that is acute (e.g., the angle of orientation between the second nozzle  272   b  and a third nozzle  272   c ). 
     A cross-sectional view  280  along line C-C is provided in  FIG. 4C . As shown, the fluid ejection die  270  may comprise at least one fluid feed hole  282  for at least two nozzles  272   c ,  272   d . Each nozzle  272   c ,  272   d  may be fluidically coupled to a fluid ejection chamber  284   a ,  284   b , and each fluid ejection chamber  284   a ,  284   b  may be fluidically coupled to the at least one fluid feed hole  282 . In addition, similar to other examples, the die  270  may comprise at least one fluid actuator  286  disposed in each fluid ejection chamber  284   a ,  284   b.    
     In  FIG. 4D , the example fluid ejection die  300  includes a plurality of nozzles  302   a - x  arranged along a length and width of the die  300  in two nozzle columns  304   a ,  304   b . In this example, groups of three neighboring nozzles  302   a - x  may be sequential columnar nozzles. The groups of three neighboring nozzles may be alternately arranged in a respective nozzle column  304   a ,  304   b  such that each group of three nozzles  302   a - x  is spaced apart along the die width from a respective group of nozzles  302   a - x  corresponding to the next three neighboring nozzles. Accordingly, similar to the example of  FIG. 4C , at least some nozzles  302   a - x  of a respective nozzle column  304   a ,  304   b  may be spaced apart by a first distance (an example of which is indicated with dimension line  306   a ) and at least some nozzles  302   a - x  of a respective nozzle column  304   a ,  304   b  may be spaced apart by a second distance (an example of which is indicated with dimension line  306   b ), where the first distance and the second distance may be different. 
       FIG. 4E  illustrates an example fluid ejection die  350  in which a plurality of nozzles  352   a - x  are arranged along a length and a width of the die  350  in at least three nozzle columns  354   a - c . Accordingly, some examples may include at least three staggered nozzle columns. In this example, an array of ribs  356  are illustrated in dashed line, as the ribs are positioned on an underside of the die  350 . As shown, the ribs  356  may be aligned with diagonals along which sets of neighboring nozzles may be arranged. 
     Turning now to  FIG. 5A , this figure provides an example fluid ejection die  400  that includes a plurality of nozzles  402   a - x  arranged along the die length and the die width in at least four nozzle columns  404   a - d . In this example, a set of neighboring nozzles  402   a - x  may comprise four nozzles (e.g., a first set of neighboring nozzles may be a first nozzle  402   a  through a fourth nozzle  402   d ). Furthermore, nozzles within a neighboring nozzle group may be arranged along a diagonal  406  with respect to the length and width of the die. An example angle of orientation  408  is provided between the first nozzle  402   a  and a second nozzle  402   b , where the angle of orientation  408  may correspond to the diagonal  406  along which neighboring nozzles may be arranged. In some examples, the diagonal  406  along which neighboring nozzles  402   a - x  may be arranged may be oblique with respect to the length of the die, and the diagonal  406  may be oblique with respect to the width of the die. In examples similar to the example die  400 , each set of neighboring nozzles (e.g., the first nozzle  402   a  to the fourth nozzle  402   d ; a fifth nozzle  402   e  to an eighth nozzle  402   h ; etc.) may be arranged along parallel diagonals. 
       FIG. 5B  provides a cross-sectional view  430  along view line D-D of  FIG. 5A , and  FIG. 5C  provides a cross-sectional view  431  of the example die  400  of  FIG. 5A  along view line E-E. In this example, the die  400  includes an array of ribs  432  that define an array of fluid circulation channels  434   a - b . Furthermore, the cross-sectional view  430  of  FIG. 5B  includes dashed line depictions of the fourth nozzle  402   d , a seventh nozzle  402   g , and an 11th nozzle  402   k  to illustrate the relative positioning of such nozzles  402   d ,  402   g ,  402   k  with respect to the ribs  432  of the array of ribs and the fluid circulation channels  434   a - b  defined thereby. Referring to  FIG. 5C , this figure includes dashed line representations of a 21st nozzle  402   u , a 22nd nozzle  402   v , a 23rd nozzle  402   w , and a 24th nozzle  402   x.    
     Furthermore, it may be appreciated that the view line D-D along which the cross-sectional view  430  is presented is approximately orthogonal to the diagonal  406  along which sets of neighboring nozzles may be arranged. Accordingly, other nozzles of the neighboring nozzle sets in which the fourth nozzle  402   d , the seventh nozzle  402   g , and the 11th nozzle  402   k  are grouped may be aligned with the depicted nozzles in the cross-sectional view  430 . Similarly, it may be appreciated that other nozzles of the first nozzle column  404   a , second nozzle column  404   b , third nozzle column  404   c , and fourth nozzle column  404   d  may be aligned with the example nozzles  402   u - x  illustrated in the cross-sectional view  431  of  FIG. 5C . 
     In addition, as shown in dashed line, each respective nozzle  402   d ,  402   g ,  402   k ,  402   u - x  may be fluidically coupled to a respective fluid ejection chamber  438   a - c ,  438   u - x . While not shown, the die  400  may include, in each fluid ejection chamber  438   a - c ,  438   u - x  at least one fluid actuator. Furthermore, each respective fluid ejection chamber  438   a - c ,  438   u - x  may be fluidically coupled to a respective first fluid feed hole  440   a - c , and each respective fluid ejection chamber  438   a - c ,  438   u - x  may be fluidically coupled to a respective second fluid feed hole  442   a - c ,  442   u - x . In the cross-sectional view  431  of  FIG. 5C , the first respective fluid feed hole is not shown, as the cross-sectional view line is positioned such that the first respective fluid feed hole is not included. The respective second fluid feed hole  442   u - x  for a respective ejection chamber  438   u - x  is illustrated in dashed line because it may be spaced apart from the view line. 
     In this example, a top surface  450  of each rib  432  of the array of ribs may be adjacent to and engage with a bottom surface  452  of a substrate  454  in which the fluid ejection chambers and fluid feed holes may be at least partially formed. Accordingly, the bottom surface  452  of the substrate may form an interior surface of the fluid circulation channels  434   a - b . As shown in  FIG. 5B , the bottom surface  452  of the substrate may be opposite a top surface  456  of the substrate  454 , where the top surface  456  of the substrate  454  may be adjacent a nozzle layer  460  in which the nozzles  402   d ,  402   g ,  402   k  may be formed. In this example, a portion of the fluid ejection chambers  438   a - c ,  438   u - x  may be defined by a surface of the nozzle layer  460  disposed above the portion of the fluid ejection chambers  438   a - c  formed in the substrate  454 . In other examples, ejection chambers, nozzles, and feed holes may be formed in more or less layers and substrates. A bottom surface  462  of each rib  432  may be adjacent to a top surface  464  of an interposer  466 . Accordingly, in this example, the fluid circulation channels  434   a - b  may be defined by the fluid circulation ribs  432 , the substrate  454 , and the interposer  466 . Accordingly, as shown  FIGS. 5B-5C , the fluid ejection die  400  includes an array of fluid feed holes  440   a - c ,  442   a - c ,  442   u - x  formed through the bottom surface  452  of the fluid ejection die  400 . 
     In examples similar to the example of  FIGS. 5A-C , fluid circulation channels may be arranged to facilitate circulation of fluid through fluid ejection chambers. In the example, the respective first fluid feedhole  440   a - c  may be fluidically coupled to a respective first fluid circulation channel  434   a  such that fluid may be conveyed from the respective first fluid circulation channel  434   a  to the respective fluid ejection chamber  438   a - c ,  438   u - x  via the respective first fluid feed hole  440   a - c . Similarly, each respective second fluid feed hole  442   a - c ,  442   u - x  may be fluidically coupled to a respective second fluid circulation channel  434   b  such that fluid may be conveyed from the respective fluid ejection chamber  438   a - c ,  438   u - x  to the respective second fluid circulation channel  434   b  via the respective second fluid feed hole  442   a - c ,  442   u - x . The respective first fluid circulation channels  434   a  and the respective second fluid circulation channels  434   b  may be fluidly separated by the ribs  432  along some portions of the die  400  such that fluid flow may occur solely through the feed holes  440   a - c ,  442   a - c  and the ejection chambers  438   a - c.    
     Accordingly, the respective first fluid circulation channels  434   a  may correspond to fluid input channels through which fresh fluid may be input to fluid ejection chambers  438   a - c . Some fluid input to the ejection chambers  438   a - c  may be ejected via the nozzles  402   d ,  402   g ,  402   k  as fluid drops. However, to facilitate circulation through the ejection chambers  438   a - c , some fluid may be conveyed from the ejection chambers  438   a - c  back to the respective second fluid circulation channels  434   b , which may correspond to fluid output channels. 
     Referring to  FIGS. 5A and 5B , it should be noted that the ribs  432  of the array of ribs, and the fluid circulation channels  434   a - b  partially defined thereby may be parallel to the diagonals  406  through which neighboring nozzles  402   a - x  are also arranged. Furthermore, as shown, in this example, the respective first fluid feed holes of nozzles  402   a - x  of sets of neighboring nozzles may be commonly coupled to a respective fluid circulation channel  434   a , and the respective second fluid feed holes of nozzles  402   a - x  of sets of neighboring nozzles may be commonly coupled to a respective fluid circulation channel  434   b . In this example, the fluidic arrangement of the ejection chambers  438   a - c , the first fluid feed holes  440   a - c , and the second fluid feed holes  442   a - c  may be described as straddling respective ribs  432  of the array of ribs. 
     For example, as shown in  FIG. 5B , the respective first fluid feed hole  440   b  coupled to the seventh nozzle  402   g  and the respective first fluid feed hole  440   c  coupled to the 11th nozzle  402   k  are fluidically coupled to a respective first fluid circulation channel  434   a . Similarly, the respective second fluid feed hole  442   a  coupled to the fourth nozzle  402   d  and the respective second fluid feed hole  442   b  coupled to the seventh nozzle  402   g  are fluidically coupled to a respective second fluid circulation channel  434   b . Since neighboring nozzles  402   a - x  are aligned with the nozzles  402   d ,  402   g ,  402   k  shown in  FIG. 5B  along a respective rib  432 , it may be noted that fluid feed holes associated with neighboring nozzles of each respective nozzle shown  402   d ,  402   g ,  402   k  may be similarly arranged. 
     As shown in  FIG. 5B , ejection chambers  438   a - c  may be disposed in the substrate above respective ribs  432 , and the fluid feed holes  440   a - c ,  442   a - c  coupled to a respective fluid ejection chamber  438   a - c  may be positioned on opposite sides of the respective rib  432  such that fluid input to the respective ejection chamber  438   a - c  via the respective first fluid feed hole  440   a - c  may be fluidly separated from fluid output from the respective ejection chamber  438   a - c  via the respective second fluid feed hole  442   a - c.    
     As shown in  FIGS. 5B-C , the top surface  464  of the interposer  466  may form a surface of the fluid circulation channels  434   a - b . Furthermore, the interposer  466  may be positioned with respect to the substrate  454  and the ribs  432  such that a die fluid input  480  and a die fluid output  482  may be at least partially defined by the interposer  466  and/or the substrate  454 . In such examples, the die fluid input  480  may be fluidically coupled to the fluid circulation channels  434   a - b , and the die fluid output  482  may be fluidically coupled to the fluid circulation channels  434   a - b.    
       FIG. 6  provides an illustration of an example fluid ejection die  500  in which a plurality of nozzles is arranged along a length and a width of the fluid ejection die  500 . In this example, the nozzles are arranged into eight nozzle columns  502   a - h , which may be referred to as staggered nozzle columns. Accordingly, some examples herein may include at least eight staggered nozzle columns. As may be noted, the nozzles are not labeled in  FIG. 6  for clarity.  FIG. 7  provides an illustration of an example fluid ejection die  550  in which a first plurality of nozzles  552   1 - 552   48  and a second plurality of nozzles  554   1 - 554   48  are arranged along a length and width of the fluid ejection die  550 . In this example, the first plurality of nozzles  552   1 - 552   48  are arranged in a first set of nozzle columns  556   a - h , and the second plurality of nozzles  554   1 - 554   48  are arranged in a second set of nozzle columns  558   a - h . Therefore, some examples may include at least 16 staggered nozzle columns. In some such examples, an example die may include a first set of at least 8 staggered nozzle columns, and a second set of at least 8 staggered nozzle columns. 
     In this example, the die  550  may include a first array of ribs  560  that define a first array of fluid circulation channels, and the die  550  may further include a second array of ribs  562  that define a second array of fluid circulation channels. In  FIG. 7 , the arrays of ribs  560 ,  562  are illustrated in dashed line since the arrays are located under the nozzles  552   1 - 552   48 ,  554   1 - 554   48  and corresponding fluid ejection chambers (not shown). Furthermore, the first array of ribs  560  may be disposed proximate a first interposer  570 , such that the first interposer forms a surface of the first array of fluid circulation channels. The second array of ribs  562  may be disposed proximate a second interposer  572 , such that the second interposer  572  forms a surface of the second array of fluid circulation channels. As may be noted, in this example, the arrangement of the arrays of ribs  560 ,  562 , the fluid circulation channels, and the interposers  570 ,  572  may be similar to the arrangements of similar elements for the example die  400  shown in  FIGS. 5A-C . Accordingly, while not shown, similar to the example of  FIGS. 5A-C , the example of  FIG. 7  may include a respective die fluid input and a respective die fluid output defined at least in part by each interposer  570 ,  572  for each plurality of nozzles  552   1 - 552   48 ,  554   1 - 554   48 . 
     Moreover, in this example, the first plurality of nozzles  552   1 - 552   48  may be arranged into diagonally arranged neighboring sets of nozzles. For example, the first through the eighth nozzle  552   1 - 552   8  of the first plurality may be considered a diagonally arranged set of neighboring nozzles. As shown, the ribs  560  (and the array of fluid circulation channels defined thereby) may be aligned with the diagonally arranged neighboring sets of nozzles. The second plurality of nozzles  554   1 - 554   48  and ribs of the second array of ribs  562  may be similarly arranged along parallel diagonals with respect to the length and the width of the die  550 . 
     Furthermore, in the example of  FIG. 7 , the first plurality of nozzles  552   1 - 552   48  (and fluid ejection chambers associated therewith) may correspond to a first fluid type, and the second plurality of nozzles  554   1 - 554   48  (and fluid ejection chambers associated therewith) may correspond to a second fluid type. For example, if the fluid ejection die  550  of  FIG. 7  is in the form of a printhead, the first plurality of fluid nozzles  552   1 - 552   48  may correspond to a first colorant (such as a first ink color), and the second plurality of fluid nozzles  554   1 - 554   48  may correspond to a second colorant (such as a second ink color). As another example, if the fluid ejection die  550  of  FIG. 7  is in the form of a fluid ejection die implemented in an additive manufacturing system (such as a 3-dimensional printer), the first plurality of nozzles  552   1 - 552   48  may correspond to a fusing agent, and the second plurality of nozzles  554   1 - 554   48  may correspond to a detailing agent. Therefore, as shown and described with respect to this example, the first plurality of nozzles  552   1 - 552   48  may be fluidically coupled together, and the second plurality of nozzles  554   1 - 554   48  may be fluidically coupled together. Accordingly, in some examples, the first plurality of nozzles  552   1 - 552   48  may be fluidically separated from the second plurality of nozzles  554   1 - 554   48 . In other examples, the first plurality of nozzles  552   1 - 552   48  may be fluidically coupled to the second plurality of nozzles  554   1 - 554   48 .  FIG. 8  provides a block diagram of an example fluid ejection die  600 . In this example, the fluid ejection die includes a plurality of nozzles  602  distributed across a length and width of the fluid ejection die  600  such that at least one respective pair of neighboring nozzles are positioned at different die width positions along the width of the fluid ejection die  600 . As discussed previously, a nozzle  602  may include a nozzle orifice  604  formed on a surface of a layer in which the nozzle  602  is formed through which fluid drops may be ejected. The die  600  further includes a plurality of ejection chambers  608  that includes, for each respective nozzle  602 , a respective ejection chamber  606  that is fluidically coupled to the nozzle  602 . The fluid ejection die  600  further comprises at least one fluid actuator  608  disposed in each ejection chamber  606 . The fluid ejection die  600  further includes an array of fluid feed holes  609  formed on a surface of the die  600  opposite a surface through which the nozzles  602  are formed. In this example, the array of fluid feed holes  609  of the die  600  includes at least one respective fluid feed hole  610  fluidically coupled to each ejection chamber  606 . 
       FIG. 9  provides a block diagram of an example fluid ejection device  650 . As shown, the fluid ejection device  650  includes a support structure  652  through which at least one fluid supply channel  653  may be formed. The fluid ejection device  650  includes at least one fluid ejection die  654 , where the at least one fluid ejection die  654  may include a plurality of nozzles  655  distributed across a length of the die and a width of the die  654 , each nozzle  655  includes a nozzle orifice  656  from which fluid drops may be ejected Furthermore, the die  654  may include a plurality of ejection chambers  657 , where, for each respective nozzle  655 , the die  650  includes a respective fluid ejection chamber  657  and at least one fluid actuator  658  disposed therein. The fluid ejection die  654  further includes an array of fluid feed holes  659 , where the array of fluid feed holes  659  includes a respective first fluid feed hole  660  and a respective second fluid feed hole  662  fluidically coupled to each respective ejection chamber  657 . Each respective first fluid feed hole  660  may be fluidically coupled to a respective first fluid circulation channel  664 , and each respective second fluid feed hole may be fluidically coupled to a respective second fluid circulation channel  668 . The first fluid circulation channels  664  and the second fluid circulation channels  668  may be fluidically coupled to the at least one fluid circulation channel  653 . Accordingly, for the fluid ejection device  650  the at least one fluid supply channel  653 , the fluid circulation channels  664 ,  668 , the fluid feed holes  660 ,  662 , the ejection chambers  657 , and the nozzles  655  may be fluidically coupled together. 
       FIG. 10A  provides a block diagram illustrates an example layout of a fluid ejection device  700 . In this example, the fluid ejection device  700  comprises a plurality of fluid ejection dies  702   a - e  arranged along a width  704  of a support structure  706  of the fluid ejection device  700 . In this example, the plurality of fluid ejection dies  702   a - e  are arranged end-to-end in a staggered manner along the width  706  of the support structure  706 . Furthermore, as shown in dashed line, a first fluid supply channel  708   a  and a second fluid supply channel  708   b  may be formed through the support structure  706  along the width  704  of the support structure  706 . A first set of fluid ejection dies  702   a - c  may be arranged generally end-to-end and fluidically coupled to the first fluid supply channel  708   a , and a second set of fluid dies  702   d - e  may be arranged generally end-to-end and fluidically coupled to the second fluid supply channel  708   b.    
     Detail view  720  of  FIG. 10A  provides a block diagram that illustrates some components of fluid ejection dies  702   a - e  of the example fluid ejection device  700 . Similar to other examples described herein, in the example of  FIG. 10A , the fluid ejection die  702   d  may include a plurality of nozzles  722  distributed along a length and width of the die  702  such that at least one neighboring nozzle of a respective nozzle of the plurality is spaced apart along the width of the die  702 . In this example, each nozzle  722  is fluidically coupled to a respective ejection chamber  724 , and each ejection chamber  724  is fluidically coupled to at least one feed hole  726 . Each fluid feed hole  726  may be fluidically coupled to a respective fluid circulation channel  728 . The fluid circulation channels  728  are defined by an array of ribs  730 . The fluid circulation channels  728  of the example die  702   d  may be fluidically coupled to the second fluid supply channel  708   b . Accordingly, in this example, the nozzles  722  may be fluidically coupled to the second fluid supply channel  708   b  via the ejection chambers  724 , the feed holes  726 , and the fluid circulation channels  728 . 
       FIG. 10B  provides a cross-sectional view  750  along view line F-F of  FIG. 10A . In this example, the fluid ejection dies  702   c ,  702   e  may be at least partially embedded in the support structure  704 . As may be noted in this example, a top surface of the fluid ejection dies  702   c ,  702   e  may be approximately planar with a top surface of the support structure  706 . In other examples, the fluid ejection dies  702   c ,  702   e  may be coupled to a surface of the support structure  706 . In this example, each fluid ejection die  702   c ,  702   e  comprises nozzles, ejection chambers, and fluid feed holes  722 - 726  (which are collectively labeled in  FIG. 10B  for clarity). In  FIG. 10B , the fluid ejection dies  702   c ,  702   e  may be similar to the example fluid ejection die  400  of  FIGS. 5A-C . Accordingly, the dies  702  may include an interposer  752  and ribs  730  that define fluid circulation channels  728 . As shown, the interposer  752  of each fluid ejection die  702   c ,  702   e  at least partially defines a die fluid input  762  and a die fluid output  764  through which fluid may flow from the fluid supply channels  708   a - b  into the fluid circulation channels  728  of each fluid ejection die  702   c ,  702   e.    
     Furthermore, as shown in  FIG. 10B , the fluid ejection device  750  may comprise fluid separation members  780  positioned in the fluid supply channels  708   a - b . In such examples, the fluid separation members  780  may engage the interposers  752 . The fluid separation members may fluidically separate the die fluid inputs  762  and the die fluid outputs  764  in the fluid channels  708   a - b . In some examples, separation of the fluid channels  708   a - b  by the fluid separation members  780  may facilitate applying a pressure differential across the die fluid inputs  762 , and the die fluid outputs  764 , where such pressure differential may generate cross-die fluid circulation through the array of fluid circulation channels  728 . 
       FIG. 11  provides a cross-sectional view of an example fluid ejection device  800 . In this example, the fluid ejection device  800  includes a fluid ejection die  802  coupled to a support structure  804 . In this example, the fluid ejection die  802  may be similar to the example fluid ejection die  550  of  FIG. 7 . Accordingly, the fluid ejection die  800  comprises a first plurality of nozzles  806 , corresponding ejection chambers, and corresponding fluid feed holes, which are collectively labeled in the example for clarity. The die further includes a second plurality of nozzles  810 , corresponding ejection chambers, and corresponding fluid feed holes, which are all collectively labeled for clarity. 
     The example die  802  further includes a first interposer  810  and a first array of ribs  812  disposed under the first plurality of nozzles  806  such that the first interposer  810  and the first array of ribs  812  form a first array of fluid circulation channels  814 . The fluid ejection device  800  includes a first fluid supply channel  816  formed through the support structure  804  and fluidically coupled to a first die fluid input  818  and a first die fluid output  820  of the fluid ejection die  802 . As shown, the first die fluid input  818  and the first die fluid output  820  are fluidically coupled to the first array of fluid circulation channels  814 . 
     Furthermore, the example die  800  includes a second interposer  822  and a second array of ribs  824  disposed under the second plurality of nozzles  808  such that the second interposer  822  and the second array of ribs  824  form a second array of fluid circulation channels  826 . The fluid ejection device  800  includes a second fluid supply channel  828  formed through the support structure  804  and fluidically coupled to a second die fluid input  830  and a second die fluid output  832 . As shown, the second die fluid input  830  and the second die fluid output  832  are fluidically coupled to the second array of fluid circulation channels  826 . 
     As shown in  FIG. 11 , the first plurality of nozzles  806  and corresponding fluid components fluidically coupled thereto (e.g., ejection chambers, fluid feed holes, fluid circulation channels, etc.) may be fluidly separated from the second plurality of nozzles  808  and corresponding fluid components fluidically coupled thereto. Accordingly, different types of fluids may be ejected from the first plurality of nozzles  806  and the second plurality of nozzles  808 . For example, if the fluid ejection device is in the form of a printhead, the first fluid supply channel  816  may convey a first color of printing material to the first plurality of nozzles  806 , and the second fluid supply channel  828  may convey a second color of printing material to the second plurality of nozzles  808 . Furthermore, while only one fluid ejection die  802  is illustrated in the example fluid ejection device of  FIG. 11 , other example fluid ejection devices may include more fluid ejection dies  802 . For example, an example fluid ejection device may include a plurality of fluid ejection dies similar to the fluid ejection die  802  of  FIG. 11 , where the plurality of fluid ejection dies may be arranged generally end-to-end in a staggered manner along a width of a support structure of the fluid ejection device, similar to the example arrangement illustrated in  FIG. 10A . 
     Moreover, in  FIG. 11 , the fluid ejection device  800  of  FIG. 11  includes fluid separation members  840  disposed in the fluid supply channels  816 ,  828  and engaging the interposers  810 ,  822 . In such examples, the fluid separation members  840  may fluidically separate the die fluid inputs  818 ,  830  and the die fluid outputs  820 ,  832  in the fluid supply channels  816 ,  828 . By fluidically separating the die fluid inputs  818 ,  830  and the die fluid outputs  820 ,  832  in the fluid channels  816 ,  828 , fluid flow through the array of fluid circulation channels  814 ,  826  of the die  802  may be caused by applying a pressure differential between the die fluid inputs  818 ,  830  and the die fluid outputs  820 ,  832 . 
     Accordingly, examples provided herein may provide a fluid ejection die including nozzle arrangements in which at least some nozzles may be distributed along a length and a width of the fluid ejection die. Some examples may include arrangements of nozzles in which nozzle columns may be spaced apart along a width of the fluid ejection die in a staggered manner, similar to the example illustrated in  FIG. 1 . In other examples, fluid ejection dies may include nozzle arrangements in which some neighboring nozzles may be aligned in a respective nozzle column, while other neighboring nozzles may be spaced apart such that the other neighboring nozzles are in at least one different nozzle column, similar to the examples shown in  FIGS. 4C and 4D . Other examples may include various combinations of example nozzle arrangements described herein. 
     Moreover, the numbers and arrangements of nozzles and other components described herein and illustrated in the figures are merely for illustrative purposes. As described above, some example fluid ejection dies contemplated hereby may include at least 40 nozzles per nozzle column. In some examples, fluid ejection dies may include at least 100 nozzles per nozzle column. In still other examples, some fluid ejection dies may include at least 200 nozzles per column. In some examples, each nozzle column may include less than 400 nozzles per nozzle column. In some examples, each nozzle column may include less than 250 nozzles per nozzle column. Similarly, some examples may include more than 500 nozzles on an example fluid ejection die. Some examples may include at least than 1000 nozzles on an example fluid ejection die. Some examples may include at least 1200 nozzles on a fluid ejection die. In some examples, the fluid ejection die may include at least 2400 nozzles. In some examples, the fluid ejection die may include less than 2400 nozzles. 
     As described above and illustrated in various figures provided herein, arrangements of nozzles as described herein may be according to some dimensional relationships such that aerodynamic effects caused due to fluid drop ejection may be reduced and/or controlled. In some examples, at least one pair of neighboring nozzles may be spaced apart along a width of the fluid ejection die by at least approximately 50 μm. In some examples, at least one neighboring nozzle pair may be spaced apart along a width of the fluid ejection die by at least 100 μm. In some examples, a respective distance along a width of a fluid ejection die between two respective nozzles of a respective neighboring nozzle pair may be within a range of approximately 100 μm and 1200 μm. 
     Similarly, in some examples, a respective distance along a length of a fluid ejection die between at least two sequential nozzles of a respective nozzle column may be at least approximately 50 μm. In some examples, a respective distance along a length of a fluid ejection die between at least two sequential nozzles of a respective nozzle column may be at least approximately 100 μm. In some examples, a respective distance along a length of a fluid ejection die between at least two sequential nozzles of a respective nozzle column may be within a range of approximately 100 μm to approximately 400 μm. In some examples, such distances between nozzles may be different between different neighboring nozzle pairs and/or sequential nozzles of a respective column. 
     In addition, in examples contemplated hereby, fluid ejection dies may include more nozzle columns or less nozzle columns than the examples described herein. In examples, at least three nozzle columns may be fluidically coupled together such that nozzles of such nozzle columns may eject drops of a particular fluid. For example, some fluid ejection dies may include at least four nozzle columns spaced apart along the width of the die, where the nozzles may be fluidically coupled such that nozzles of the nozzle columns may eject drops of a particular fluid. Some examples contemplated hereby may include at least 16 nozzle columns fluidically coupled such that a particular fluid may be ejected by nozzles of the 16 nozzle columns. In such examples, a nozzle column to nozzle column distance may be at least 100 μm. In some examples, a nozzle column to nozzle column distance may be at least 200 μm. In some examples, a nozzle column to nozzle column distance may be in a range of approximately 200 μm to approximately 1200 μm. 
     Furthermore, in some examples, each nozzle column may include approximately 50 nozzles to approximately 200 nozzles per inch of length of a die. In some examples, each nozzle column may include less than 250 nozzles per inch of length of a die. In some examples contemplated herein, a nozzle-to-nozzle spacing of sequential columnar nozzles may be greater than a nozzle column to nozzle column spacing. In other examples, a nozzle-to-nozzle spacing of sequential columnar nozzles may be less than a nozzle column to nozzle column spacing. 
     The preceding description has been presented to illustrate and describe examples of the principles described. This description is not intended to be exhaustive or to limit these principles to any precise form disclosed. Many modifications and variations are possible in light of the description. In addition, while various examples are described herein, elements and/or combinations of elements may be combined and/or removed for various examples contemplated hereby. For example, the components illustrated in the examples of  FIGS. 1-11  may be added and/or removed from any of the other figures. Furthermore, the term “approximately” when used with regard to a value may correspond to a range of ±10%. Approximately, when used with regard to an angular orientation may correspond to a range of approximately ±10°. Therefore, the foregoing examples provided in the figures and described herein should not be construed as limiting of the scope of the disclosure, which is defined in the Claims.