BACKGROUND

[0001] Fluid droplets are utilized in a variety of applications such as printing, additive manufacturing, environmental testing and biomedical diagnostics. For example, such fluid droplets may comprise an ink, a binder or other similar materials with respect to printing and additive manufacturing. With respect to environmental testing and biomedical diagnostics, such fluid droplets may comprise a reactant, a stain or an analyte. In many applications, the provision of the fluid droplet is automated through the use of a fluid ejector.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] FIG. 1 is a block diagram illustrating portions of an example integrated fluid ejection and imaging head.

[0003] FIG. 2 is a bottom view schematically illustrating portions of an example 2D imaging array of the head of FIG. 1.

[0004] FIG. 3 is a flow diagram of an example integrated fluid ejection and imaging method.

[0005] FIG. 4 is a flow diagram of an example method for forming an example integrated fluid ejection and imaging head.

[0006] FIG. 5 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[0007] FIGS. 6A is a top view of an example flat lens for the system of

FIG. 5. 0

[0008] FIG. 6B is an enlarged view of a portion of the flat lens of FIG.

6A.

[0009] FIG. 6C is a further enlarged view a portion of the flat lens of

FIG. 6B.

[00010] FIG. 7A is a top view of an example flat lens for the system of FIG. 5.

[00011] FIG. 7B is an enlarged view of a portion of the flatlands of FIG.

7 A.

[00012] FIG. 8 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00013] FIG. 9 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00014] FIG. 10 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00015] FIG. 11 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00016] FIG. 12 is a bottom view taken along line 12-12 of FIG. 11 and illustrating one example of layout of fluid ejectors and imagers on a package.

[00017] FIG. 13 is a bottom view taken along line 12-12 of FIG. 11 and illustrating one example of layout of fluid ejectors and imagers on a package.

[00018] FIG. 14 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00019] FIG. 15 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system. 0

[00020] FIG. 16 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00021] FIG. 17 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00022] FIG. 18 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00023] FIG. 19 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00024] FIG. 20 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00025] FIG. 21 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system.

[00026] Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements. The FIGS 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.

DETAILED DESCRIPTION OF EXAMPLES

[00027] Disclosed are example integrated fluid ejection and imaging heads and methods. Also disclosed are example methods for forming an integrated fluid ejection and imaging head. The integrated fluid ejection and imaging heads and methods comprise a fluid ejector, a two-dimensional imaging array and a flat lens, each of such components being integrated and supported by single packaging. As a result, the packaging may support the 0 two-dimensional imaging array at a preestablished position relative to the flat lands and the fluid ejector, simplifying focusing and other tasks associated with two-dimensional imaging of the head or the flight of droplets ejected from the head. Information obtained through the imaging of the head or the flight of droplets ejected from the head may be used to evaluate performance of the head and adjust operational characteristics of the head for enhanced results.

[00028] In some implementations, the example integrated fluid ejection and imaging heads and methods capture two-dimensional images of the head from which droplets are ejected. In some implementations, a reflective surface reflects an image of an ejection orifice or the ejection head through the flat lens to the two-dimensional imaging array. In some implementations, the reflective surface is supported by the same packaging that supports the fluid ejector, the two-dimensional imaging array and the flat lens. In some implementations, two-dimensional images of the head and flight of a droplet are both captured.

[00029] In some implementations, additional mechanisms are provided to inhibit satellite droplets from becoming deposited between the reflective surface and the two-dimensional imaging array. In some implementations, a drop deflector may be used to deflect satellite droplets away from the reflective surface and/or flat lens. In some implementations, a baffle may be used to block satellite droplets. In some implementations, the two- dimensional imaging array and flat lens are movable relative to the fluid ejector to facilitate servicing of the fluid ejector. In those implementations that may include the baffle to block satellite droplets, the baffle may also be movable relative to the fluid ejector to facilitate servicing of the fluid ejector.

[00030] Disclosed is an example integrated fluid ejection and imaging head that may include a fluid ejector to eject a droplet of fluid through an ejection orifice, a two-dimensional imaging array, a flat lens and a packaging supporting the fluid ejector. The packaging may support the two-dimensional imaging array and the flat lens as a single unit with the flat lens focused on the two-dimensional array of sensing elements.

[00031] Disclosed an example integrated fluid ejection and imaging method. The example method may include focusing light onto a two- dimensional imaging array of imaging elements with a flat lens supported by a packaging that also supports a fluid ejector, capturing an image with the two- dimensional imaging array of imaging elements and adjusting operation of the fluid ejector based upon the image.

[00032] Disclosed is an example method for forming an example integrated fluid ejection and imaging head. The method may include forming a fluid ejector to eject a droplet of fluid, forming a two-dimensional imaging array of imaging elements, forming a flat lens to focus light onto the two- dimensional imaging array and integrating the fluid ejector, the two- dimensional imaging array and the flat lens as part of a single package.

[00033] FIG. 1 schematically illustrates portions of an example integrated fluid ejection and imaging head 20. Head 20 integrates fluid ejector, a flat lens and a two-dimensional imaging array as part of a single package. Head 20 comprises fluid ejector 24, two-dimensional imaging array 28, flat lens 30 and packaging 40.

[00034] Fluid ejector 24 comprises a device to selectively eject fluid droplets towards and onto a deposition site on an example target. In one implementation fluid ejector 24 is electrically powered and controlled through the transmission of electrical signals. In one implementation, fluid ejector 24 comprises a fluid ejection chamber that is supplied with fluid from a fluid reservoir, the fluid to be ejected by a fluid actuator that is selectively actuated to displace fluid within the chamber through an ejection orifice or nozzle opening. 0

[00035] In one implementation, the fluid actuator may comprise a thermal resistor which, upon receiving electrical current, heats to a temperature above the nucleation temperature of the fluid so as to vaporize a portion of the adjacent fluid to create a bubble which displaces the fluid through the associated orifice. In other implementations, the fluid actuator may comprise other forms of fluid actuators. In other implementations, the individual fluid actuators may be in the form of a piezo-membrane based actuator, an electrostatic membrane actuator, mechanical/impact driven membrane actuator, a magneto-strictive drive actuator, an electrochemical actuator, and external laser actuators (that form a bubble through boiling with a laser beam), other such microdevices, or any combination thereof.

[00036] Two-dimensional (2D) imaging array 28 comprises a two- dimensional array of imaging elements, each element outputting electrical signals based upon and in response to the impingement of light upon such elements. FIG. 2 is a bottom view illustrating a portion of an example 2D imaging array 28. As shown by FIG. 2, 2D imaging array 28 may comprise multiple individual imaging elements 29 extending in two dimensions. Although the example array 28 is illustrated as comprising a 4 x 4 array of imaging elements 29, it should be appreciated that 2D imaging array 28 may comprise other numbers of multiple imaging elements 29 extending in two dimensions. 2D imaging array 28 facilitates the capture of a two-dimensional image of head 20 or droplets ejected by fluid ejector 24 of head 20. In some implementations, the imaging elements 29 of 2D imaging array 28 may each comprise a complementary metal-oxide-semiconductor (CMOS), a charge coupled device (CCD) sensor element, a photodiode (PiN), photo-resistive sensor element or other types of a sensing element.

[00037] Flat lens 30 focuses light (schematically represented by arrow 33) onto the two-dimensional imaging array 28. Examples of flat lens 30 include, but are not limited to, Fresnel lenses, zone plate lenses and meta- lenses. Such lenses may include an amplitude mask for computational imaging.

[00038] Packaging 40 integrates fluid ejector 24, 2D imaging array 28 and flat lens 30 as a single unit or package. In one implementation, packaging 40 extends along a backside of and is directly connected to fluid ejector 24, 2D imaging array 20 a and flat lens 30. In an example implementation, packaging 40 partially encapsulates fluid ejector 24 and 2D imaging array 28, extending on a back side of fluid ejector 24 and 2D imaging array 28. In an example implementation, packaging 40 comprises a liquid or moldable material which is molded about portions of fluid ejector 24 and 2D imaging array 28 and then solidified or hardened such as through curing or evaporation to form the single integral package surrounded by a single monolithic layer.

[00039] In some implementations, packaging 40 supports fluid ejector 24, 2D imaging array 28 and flat lens 30 such that flat lens 30 is supported at a preestablished position and orientation so as to focus light from the ejection face or ejection orifice of fluid ejector 24 and/or from any ejected droplet in flight onto 2D imaging array 28. The flat lens 30 may be supported at a fixed spacing relative to the 2D imaging array 28 to correctly focus light onto the 2D imaging array. In some implementations, the flat lens 30 may be at a fixed or preestablished orientation and location so as to be accurately aimed at the ejection face orifice. In some implementations, flat lens may be at a fixed or preestablished orientation and location to capture two-dimensional image of any ejected droplet in-flight following a predetermined lapse of time from the ejection of the droplet. As a result, time-consuming focusing and alignment procedures may be reduced or eliminated.

[00040] FIG. 3 is a flow diagram of an example integrated fluid ejection and imaging method 100. Method 100 facilitates two-dimensional imaging of the fluid ejection head itself or of an ejected droplet in-flight. Although method 0

100 is described in the context of being carried out by system 20, it should be appreciated that method 100 may likewise be carried out with any of the systems described hereafter or with other similar systems.

[00041] As indicated by block 104, light is focused onto two-dimensional imaging array 28 with a flat lens 30 supported by packaging 40 that also supports fluid ejector 24. As indicated by block 108, the two-dimensional imaging array 28 captures a two-dimensional image. The image may be that of an ejection face of the fluid ejector, such as an image of an ejection orifice of the fluid ejector. The image may be that of an ejected droplet in-flight.

[00042] As indicated by block 112, operation of the fluid ejector 24 may be adjusted based upon the captured two-dimensional image. For example, a two-dimensional image of the ejection face of the fluid ejector 24, a two- dimensional image of an ejection orifice, may reveal partial occlusion of the ejection orifice or puddling of an ejection fluid on the ejection face. A controller may analyze the captured two-dimensional image and based upon such analysis, output control signals triggering the servicing of the fluid actuator 24. For example, such servicing may involve spitting, purging or wiping operations.

[00043] A two-dimensional image of an ejected droplet in-flight may reveal that the size of the droplet is out of specification or that the droplet has an unintended trajectory. A controller may analyze the captured two- dimensional image and based upon such analysis, output control signals adjusting the timing at which droplets are ejected by fluid ejector 24 or adjusting power supplied to the fluid ejector 24. Method 100 facilitates feedback control or reaction monitoring in a much shorter amount of time or in real time.

[00044] FIG. 4 is a flow diagram of an example method 154 forming an example integrated fluid ejection and imaging head, such as head 20. As indicated by block 154, a fluid ejector to eject a droplet of fluid, such as fluid 0 ejector 24, is formed. In some implementations, the fluid ejector may be formed by depositing an electrical resistor on a substrate and patterning various layers of photo-imageable epoxy on the substrate to form an ejection chamber and orifice opposite the electrical resistor. Electrically conductive traces and control circuitry may be additionally deposited or formed on the substrate.

[00045] As indicated by block 158, a two-dimensional imaging array, such as 2D imaging array 28 is formed. In some implementations, an array of metal-oxide-semiconductor (CMOS) elements, a charge coupled device (CCD) sensor elements or other types of sensing elements may be formed upon the substrate or a separate substrate.

[00046] As indicated by block 162, a flat lens, such as flat lens 30 may be formed so as to focus light from an in-flight droplet or from the fluid ejector onto the 2D imaging array. As described above, the flat lens may comprise a Fresnel lens, a zone plate lens or a meta-lens.

[00047] As indicated by block 166, the fluid ejector, the 2D imaging array and the flat lens are integrated as part of a single package. For example, fluid ejector, the 2D imaging array and the flat lens may be integrated as part of a single package by at least partially encapsulating such components in a moldable material, such as a molding compound, which is subsequently hardened. In some implementations, the fluid ejector, the 2D imaging array and/or the flat lens may be integrated as part of a single package by being bonded or fused to a single packaging.

[00048] FIG.5 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 200. System 200 comprises an integrated fluid ejection and imaging head 220 that captures two-dimensional images of ejected in-flight droplets as they move towards target support 242. FIG. 5 illustrates particular examples of a fluid ejector and 2D imaging array as well as an illuminator integrated as part of a single package by a packaging. FIG. 5 further illustrates how an 2D imaging array 0 may be supported so as to partially overlap fluid ejector such that system 200 is more compact. Head 220 comprises fluid ejector 224, 2D imaging array 228, flat lens 230, illuminator 232, packaging 240 and controller 270.

[00049] Fluid ejector 224 comprises a device to selectively eject a fluid droplet 225 or multiple fluid drops 225 towards and onto a deposition site 244 on an example target 246. In one implementation fluid ejector 224 is electrically powered and controlled through the transmission of electrical signals. In the example implementation, fluid ejector 224 comprises circuitry platform 250, chamber layer 252, ejection orifice 254 and fluid actuator 256. [00050] Circuitry platform 250 comprises a structure incorporating electrically conductive wires, traces or the like and electronic components such as transistors, diodes and various logic elements. In one implementation, circuitry platform 250 comprises what is sometimes referred to as a thin-film structure. For example, circuitry platform 250 may comprise a silicon substrate that is doped to form electrically conductive transistors and upon which layers of materials are photolithographically patterned to form electrically conductive traces for powering and selectively actuating fluid actuator 256. In one implementation, circuitry platform 250 may comprise a circuit board supporting electronic componentry.

[00051] Chamber layer 250 comprises a layer or multiple layers of material supported and formed upon circuitry platform 250. Chamber layer 250 defines an internal chamber 260 which is fluidly connected to a source of fluid for being ejected through ejection orifice 254. In one implementation, chamber layer 250 may be formed from a photo-imageable, photoresist epoxy. In one implementation, chamber layer 250 may be formed from a Bisphenol A Novolac epoxy that is dissolved in an organic solvent (gamma- butyrolactone GBL or cyclopentanone, depending on the formulation) and up to 10 wt% of mixed Triarylsulfonium/hexafluoroantimonate salt as the photoacid generator). In other implementations, chamber layer 250 may be formed from other materials such as glass, ceramics, polymers or the like. 0

[00052] Ejection orifice 254 comprises an opening, such as a nozzle opening, through which fluid within chamber 260 is displaced and ejected. In one implementation, ejection orifice 254 is formed by an opening extending through an orifice plate secured to chamber layer 250. In another implementation, ejection orifice 254 is formed in the material forming chamber layer 250. In such an implementation, chamber layer 250 may be formed from multiple layers of the same material, wherein the bottom most layer forms the ejection orifice 254.

[00053] Fluid actuator 256 comprises a device that, upon being actuated, displaces fluid within a fluid ejection chamber of chamber layer 26 through ejection orifice or nozzle 254. In one implementation, fluid actuator 256 comprises a thermal resistor which, upon receiving electrical current, heats to a temperature above the nucleation temperature of the fluid so as to vaporize a portion of the adjacent fluid to create a bubble which displaces the fluid through the associated orifice. In other implementations, fluid actuator 256 may comprise other forms of fluid actuators. In other implementations, fluid actuator 256 may be in the form of a piezo-membrane based actuator, an electrostatic membrane actuator, mechanical/impact driven membrane actuator, a magneto-strictive drive actuator, an electrochemical actuator, and external laser actuators (that form a bubble through boiling with a laser beam), other such microdevices, or any combination thereof.

[00054] Although fluid ejector 224 is illustrated as having a single chamber 260, a single fluid ejection orifice 254 and an associated single fluid actuator 256, in other implementations, fluid ejector 224 may comprise an array of chambers 260, orifices 254 and fluid actuators 256. For example, fluid ejector 224 may comprise columns of such orifices 254 and fluid actuators 256. In one implementation, fluid ejector 224 may comprise a sliver (having a length to width ratio of 10:1 or more) partially encapsulated or surrounded by an epoxy mold compound which forms packaging 40.

[00055] 2D imaging array 228 comprises a device carried by packaging 240 that images and in-flight droplet 225 by capturing an image or images of 0 the in-flight droplet 225. In the example illustrated, 2D imaging array 228 is supported on a same side of the target 246 as fluid ejector 224. As a result, target 246, or any underlying support supporting target 246, may be opaque. In addition, 2D imaging array 228 may be more closely spaced from the in flight droplet 225. 2D imaging array 228 comprises imaging elements 229 [00056] Flat lens 230 focuses light reflected from an in-flight droplet 225 onto imaging array 228. In the example illustrated, flat lens 230 is supported by a transparent substrate 231. Transparent substrate 231 comprises a layer or multiple layers sandwiched between lens 230 and imaging array 228. Transparent substrate 231 spaces lens 230 from imaging array 228 to enhance focusing of the light from the in-flight droplet onto imaging array 228. [00057] In one implementation, transparent substrate 231 has a thickness of 20 microns or more. In some implementations, transparent substrate has a thickness of no greater than 2 mm. For optical performance, transparent substrate 231 may have a thickness of 100-500 microns. In one implementation, transparent substrate 231 may be formed from a transparent material such as SU8, quartz, or other transparent polymers, resists, PMMA, glass flavors. In other implementations, transparent substrate 231 may be formed from other transparent materials or may have other thicknesses. In some implementations, transparent substrate 231 may be omitted to enhance nozzle and optical surface servicing.

[00058] Flat lens 230 focuses the light from an in-flight droplet 225 through transparent substrate 231 and onto imaging array 228. In an implementation, flat lens 230 comprises a flat lens having a thickness of 1 pm or less, facilitating a short working distance of less than 2 mm without difficult alignment given its flat form. Particular examples of the lens 230 include Fresnel lenses, zone plate lenses and meta-lenses. The lens may include an amplitude mask for computational imaging.

[00059] FIGS. 6A, 6B and 6C illustrate lens 330, an example of lens 230. Lens 330 comprises a flat lens in the form of a meta lens. In an example implementation, lens 330 has a phase distribution that is sampled 0 approximately every 50 to 300 nm in x,y with a phase resolution of Jl/7 or less for diffraction-limited performance. As a result, focusing efficiency may be as high as 80% to 90%, but may involve the fabrication of features having a size in a range of 50 to 100 nm. In the example illustrated, the phase sampling is provided with pillars 368 (shown in FIG. 6C), also referred to as resonators, of different diameters having the illustrated distribution. In the example illustrated, the distribution of pillars 368 has a phase profile having a continuous smooth function of x,y except for zone boundaries where the phase is folded in 2 J1 to facilitate ease of fabrication. In one implementation, the pillars comprise cylindrical nano-resonators with a hexagonal configuration (five pillars equally spaced about a center pillar), the individual pillars having a height of 400 nm, a center to center spacing of 325 nm and the outer pillars 368 having an angular offset of 60°. In one implementation, the pillars may be formed from a transparent material such as PO2. In other implementations, the pillars shown in FIG. 6C may be formed from other material such as amorphous silicon or transparent polymers. The meta lens provides a high refractive index (anything above n= 1.5 to n=3 and above depending on wavelength), a low absorbency at a working wavelength range (transmission better than 70%, including absorption and scattering losses), and low roughness (at least l/4 and in some implementations, L/14 or to l/100, wherein l is the wavelength). In some implementations, the metalenses may be made from metallic nanostructures, which have significantly more losses, but might be easier to fabricate. The meta-lenses (both metallic and dielectric) may also be made of nanostructures other than pillars. Such pillars may be any shape such as square pillars, polyhedrons, v-shaped polyhedrons, and other topological deformations, coupled resonators, and so on.

[00060] FIGS. 7A and 7B illustrate lens 430, another example of lens 230. Lens 430 comprises a flat lens in the form of a zone plate. Lens 430 is phase sampled at a few discrete levels. In one implementation, the zone plate of lens 430 is sampled at two levels (0, Jl) or up to J1 /4 increments. As a 0 result, fabrication is easier due to the larger minimum feature size. In contrast to a meta lens, lens efficiency may be below 40% transmission efficiency. However, the zone plate may be fabricated with e-beam lithography out of low absorbency material such as Polydimethylsiloxane (PDMS), also sometimes referred to as dimethylpolysiloxane or dimethicone.

[00061] As further shown by FIG. 5, flat lens 230 overlaps portions of fluid ejector 224. Portions of both transparent substrate 231 and lens 230 overlap portions of fluid ejector 224. Portions of transparent substrate 231 are sandwiched between lens 230 and fluid ejector 224. As a result, lens 230 may be supported more closely to ejection orifice 254 and the anticipated trajectory for an in-flight droplet 225 for enhanced imaging of the in-flight droplet 225. In other implementations, this overlap may be omitted.

[00062] 2D imaging array 228 is supported by packaging 240. Imaging array 228 comprises an array of individual optical or light sensing elements 229 supported by an electronics platform 265. The individual optical light sensing elements 229 receive light focused by lens 230 through substrate 231 and outputs electrical signals based upon the received light. Imaging array 228 may comprise a complementary metal-oxide-semiconductor (CMOS), a charge coupled device (CCD) sensor array or other types of imaging elements. The electronics platform 265 supports electrically conductive traces, transistors and other electronic componentry for powering and operating light sensing elements 229. In one implementation, elements 229 and electronic platform 265 may comprise a thin film, a circuit board, a die or other unitary structure.

[00063] Illuminator 232 comprises an electronic component that illuminates the anticipated trajectory of fluid droplet 225 with light that may be reflected from an in-flight droplet and that may be received by flat lens 230. In an example implementation, illuminator 232 may comprise a light emitting diode. In an example implementation, illuminator 232 may comprise a laser diode for monochromatic imaging to reduce the effect of chromatic aberrations off-axis of the optical system. In other implementations, 0 illuminator 232 may comprise other light-emitting devices. In the example illustrated, illuminator 232 is supported by packaging 240. In the example illustrated, illuminator 232 is encapsulated by packaging 240. In other implementations, illuminator 232 may be surface mounted upon the overall package of system 200, such as upon a die forming system 200. In other implementations, illuminator 232 may be separate and distinct from packaging 240 and from die or head 220 forming system 200. In some implementations, such as where ambient light is sufficient, illuminator 232 may be omitted. [00064] Packaging 240 integrates fluid ejector 224 and 2D imaging array 228 as a single unit or package. In the example illustrated, packaging 240 supports imaging array 228 so as to be coplanarwith fluid ejector 224, alongside fluid ejector 224. In the example illustrated, packaging 240 extends along a backside and is directly connected to fluid ejector 224 and 2D imaging array 228. In the example illustrated, packaging 240 partially encapsulates fluid ejector 224 and 2D imaging array 228, extending on back sides of fluid ejector 224 and 2D imaging array 228 and about sides of fluid ejector 224 and/or 2D imaging array 228.

[00065] In the example illustrated, packaging 240 additionally encapsulates illuminator 232, wherein illuminator 232 is supported on an opposite side of fluid ejector 224 as 2D imaging array 228. In the example illustrated, illuminator 232 and 2D imaging array 228 are all concurrently aimed at an inflight droplet 225 such that the droplet 225 of fluid may be illuminated by illuminator 232 and may be imaged by 2D imaging array 228 without relative movement of target 246 or imaging system 200. In an example implementation, packaging 240 comprises a liquid or moldable material which is molded about portions of fluid ejector 224 and 2D imaging array 228 and then solidified or hardened such as through curing or evaporation to form the single integral package.

[00066] Target support 242 supports target 246 and deposition site 244 generally opposite to fluid ejector 224 and 2D imaging array 228. In one implementation, target support 242 may comprise an X-Y movable platform 0 for selectively positioning different deposition sites opposite to fluid ejector

224 and 2D imaging array 228. In one implementation, target support 242 supports target 246 such that deposition site 244 is spaced from fluid ejection orifice 254 by no greater than 10 mm. Although target support 242 may be used for selectively positioning different deposition sites for receiving droplets

225 from fluid ejector 224 and for concurrently being imaged by 2D imaging array 228, because packaging 240 supports fluid ejector 224 and 2D imaging array 228 such that fluid ejector 224 and 2D imaging array 228 are concurrently aimed the anticipated location or trajectory of an ejected fluid droplet 225, the imaging of the deposition site 244 may be carried out without the deposition site 244 being moved and without time consuming alignment with an independent imager. As a result, in-flight droplet trajectory feedback control or reaction monitoring may be carried out in much shorter amount of time or in real time.

[00067] Controller 270 controls operation of head 220. Controller 270 comprises a processor 272 which follows instructions contained in a non- transitory computer-readable medium 274. Based upon such instructions, processor 272 initiates the capturing of 2D images of an ejected in-flight droplet 225 and analyzes images received from 2D imaging array 228. Based upon such analysis, controller 270 may adjust the timing at which droplets 225 are being ejected by fluid ejector 224, may adjust the power or other operating characteristics of fluid ejector 224, may adjust the amount of light being output by illuminator 232 and/or may adjust the relative positioning of head 220 and target support 242. The two-dimensional images of the in-flight droplet 225 may additionally be used by controller 270 to identify characteristics, such as a chemical composition, of the fluid being ejected.

[00068] In an example implementation, system 200 has the following geometric characteristics. The spacing d between the ejection orifice and the edge of the 2D imaging array 228 is between 50 microns and 5 mm, and nominally 0.5 mm. The printing distance H is between 100 microns and 5 mm, and nominally 2 mm. The magnification M provided by the imaging array 0

228 is between 0.05x and 20x, and nominally 0.3x. The field-of-view F of 2D imaging array 228 is between 50 microns and 5 mm, and nominally 0.4 mm. The transparent substrate 231 has a thickness hi of MH/(1+M), a thickness of between 20 microns and 3 mm, and nominally 0.4 mm. The working distance h2 between lens 230 and target 246 is H-h 1 , between 100 microns and 5 mm, and nominally 1 .54 mm. The orifice to substrate edge distance D (fluidically constrained) is between 50 microns and 3 mm, and nominally 0.2 mm. In other implementations, system 200 may have other geometric characteristics which may vary depending upon the characteristics of fluid ejector 224, target 246, imaging array 228 and lens 230.

[00069] FIG. 8 is a sectional view schematic illustrating forces of an example integrated fluid ejection and imaging system 500. Imaging system 500 is similar to system 200 except that imaging system 500 comprises an example integrated fluid ejection and imaging head 520 in place of head 220. The remaining components of system 500 which correspond to components of system 200 are numbered similarly. FIG. 8 illustrates how an integrated fluid ejection and imaging head 520 may utilize a flat lens to focus an illuminating light onto an ejected in-flight droplet to facilitate enhanced two- dimensional imaging of the ejected in-flight droplet.

[00070] Head 520 is similar to head 220 described above except that head 520 additionally comprises flat lens 530 supported by transparent substrate 531 . Those remaining components of head 520 which correspond to components of head 220 are numbered similarly. Flat lens 530 is similar to flat lens 230 except that flat lens 530 receives light from illuminator 232 that is passed through transparent substrate 531 and focuses the light onto the anticipated region are location of an ejected in-flight droplet 225 at an angle such that the light reflected from the droplet 225 we reflected through flat lens 230 onto 2D imaging array 228. In some implementations, 2D images are continuously captured with the light from flat lens 530 being focused on a certain point, wherein the captured image of the droplet 225 when intersecting the focal point of the light from lens 530 may be used for analysis of the in- 0 flight droplet 225. In some implementations, the capturing of images by 2D imaging array 228 is timed based upon the time that droplet 225 is ejected and the expected or estimated amount of time for the ejected droplet to intersect the focal point of the light from flat lens 530. The focused light from lens 530 may enhance the two-dimensional images captured by 2D imaging array 228.

[00071] FIG. 9 is a sectional view illustrating portions of an example integrated fluid ejection and imaging system 600 comprising an integrated fluid ejection imaging head 620. Head 620 is similar to head 520 described above except that lenses 230 and 530 are substantially coplanar with the ejection face of fluid ejector 224. As a result, lenses 230 and 530 may be positioned closer to the ejection face of fluid ejector 224 for enhanced two- dimensional imaging. In the example illustrated, fluid ejector 224 is surrounded on opposite sides by transparent substrates 231 and 531 (which may be a single continuous monolithic layer).

[00072] FIG. 10 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 700 having an integrated fluid ejection imaging head 720. FIG. 10 illustrates the provision of multiple 2D imaging arrays 728-1 , 728-2 (collectively referred to as 2D imaging arrays 728) and associated flat lenses 730-1, 730-2 on opposite sides of fluid ejector 224. The remaining component of system 720 which correspond to components of system 220 are numbered similarly and/or are shown in FIG. 5. For example, system 720 may additionally include illuminator 232 as described above.

[00073] 2D imaging arrays 728 are each similar to the 2D imaging array shown in FIG. 5. Each of the flat lenses 730-1 , 730-2 are supported by transparent substrate 231. In addition to providing system 720 with a larger field-of-view and with imaging have different focal planes, because 2D imaging arrays 728 are located on opposite sides of fluid ejector 224, 2D imaging arrays 728 may capture or collect two different perspectives of an ejected in-flight droplet 225. In some implementations, the different images 0 captured at different perspectives may be used by a controller 770 to combine the images to provide for stereo vision and/or provide three-dimensional imaging or other information for the ejected in-flight droplet 225. In the example illustrated, controller 570 comprises a processor 772 that follows instructions contained in a computer-readable medium 774 to combine the captured images taken from different perspectives by the different 2D imaging arrays 728 to output stereo vision or three-dimensional information regarding the droplets. In some implementations, controller 770 may also function similar to controller 270 described above, controlling the timing of fluid ejection.

[00074] FIG. 11 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 800 comprising an example integrated fluid ejection imaging head 820. FIG. 11 illustrates the stacking of multiple 2D imaging arrays 228-1 , 228-2 (collectively referred to as 2D imaging arrays 228) relative to fluid ejector 224 and on opposite sides of fluid ejector 224. The remaining component of head 820 which correspond to components of head 220 are numbered similarly and/or are shown in FIG. 5. For example, system 820 may additionally include illuminator 232 and substrate 531 and flat lens 530 as described above.

[00075] Each of 2D imaging arrays 228 is similar to 2D imaging array 228 described above with respect to head 220 except that 2D imaging arrays 228-1 and 228-2 are each stacked so as to overlap fluid ejector 224. Both flat lens 230 and imaging array 228 overlap portions of fluid ejector 224.

Substrate 264 and portions of imaging array 262 are sandwiched between lens 266 and portions of chamber layer 252 of fluid ejector 224. In the example illustrated, fluid ejector 224 ejects droplets 225 along an ejection trajectory or path that extends between 2D imaging arrays 228-1 and 228-2. Because 2D imaging arrays 228 overlap portions of fluid ejector 224, the overall size of the package of head 820 is reduced. In addition, the off-axis angle A is reduced to improve image quality and aberration control while avoiding interference with fluid trajectory. 0

[00076] As described above with respect to head 720, in an example implementation, both of 2D imaging arrays 228 may be focused on the same ejected in-flight droplet 225. As a result, the droplet 225 may also be captured or observed by 2D imaging arrays 228 from multiple perspectives. The multiple different captured images taken at the different perspectives may be combined by controller 770 to output stereo vision or three-dimensional information regarding the droplets 225.

[00077] FIG. 12 is a bottom view of a portion of one implementation of head 820 taken along line 12-12 of FIG. 11. FIG. 12 illustrates one example of how the fluid ejectors and 2D imaging arrays of system 1020 may be arranged or laid out on a single integrated packaging, such as a single integrated die. In the example illustrated, the fluid ejectors 224-1 , 224-2 and 224-3 (collectively referred to as ejectors 224), formed by fluid ejection orifices 254, fluid actuator 256 and ejection chambers 260, are arranged in rows or columns along packaging 240. In the example illustrated, each of fluid ejectors 224 has its own dedicated pair of lenses 266-1 , 266-2 (collectively referred to as lenses 266). In the example illustrated, Ienses266 are offset 180 degrees, on opposite sided of orifices 254. In other implementations, lenses 266 may be angularly offset by other degrees and/or may include more than two lenses.

[00078] In the example illustrated, imaging elements 263 are formed as a single continuous band or strip of elements extending along the row or column of fluid ejectors 224. Distinct portions of the continuous band or strip of elements 263 may be associated with distinct fluid ejectors 1024. In the example illustrated, target illuminators 232 are also provided as a single continuous row or column of light emitters, such as light emitting diodes. In other implementations, each of fluid ejectors 224 may have an associated pair of imaging array elements 263 and/or target illuminators 232.

[00079] FIG. 13 is a bottom view of a portion of one implementation of system 820 taken along line 12-12 of FIG. 11. FIG. 13 illustrates one example of how the fluid ejectors and 2D imaging arrays of system 820 may 0 be arranged or laid out on a single integrated packaging, such as a single integrated die. As with the example illustrated in FIG. 12, in the example in FIG. 13, the fluid ejectors 224, formed by fluid ejection orifices 254, fluid actuator 256 and ejection chambers 260, are arranged in rows or columns along packaging 240. In the example of FIG. 13, each of fluid ejectors 224 has a lens or a group of lenses 266 that surround or encircle ejection orifice 254. Likewise, each of fluid ejectors 224 has imaging array elements 263 that collectively surround or encircle ejection orifice 254, providing a larger field of view or providing additional perspectives for the construction of a stereoscopic or 3D images of a deposition site. The circular array of lenses 266 may provide information about vertical trajectory error, for detection of weak, transient, contaminated and permanently damaged nozzles. Although elements 263 and lenses 266 are illustrated as continuously encircling their respective fluid ejection orifices 254, in some implementations, elements 263 and/or lenses 266 may be arranged in individual distinct groupings or clusters of elements or distinct groupings or clusters of lenses spaced around and about their respective fluid ejection orifices 254.

[00080] FIG. 14 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 900 comprising an example integrated fluid ejection and imaging head 920. FIG. 14 illustrates a further degree of integration as between a fluid ejector and an imager. Those portions of head 920 which correspond to portions of head 220 are numbered similarly.

[00081] As shown by FIG. 14, the same circuitry platform that supports fluid actuator 256 and its associated electronic components (electrically conductive traces and transistors) also supports and carries the imaging array and its associated electronic components. The same transparent substrate that supports lens 266 and through which light is focused by length 266 onto the imaging array also forms the chamber layer for the fluid ejector. As a result, system 920 is more compact and may be less complex or less costly to fabricate. System 920 comprises circuitry platform 950, fluid actuator 256, 0 transparent substrate 964, lens 266 and imaging array 262. In the example illustrated, portions of circuitry platform 950 and portions of transparent substrate 964 along with fluid actuator 256 form a fluid ejector. Portions of circuitry platform 950 and portions of transparent substrate 964 further form portions of an imager.

[00082] Circuitry platform 950 includes electrically conductive traces, transistors and other electronic componentry for powering and controlling both fluid actuator 256 (described above) and the optical or light sensing elements

263 (described above). Circuitry platform 950 may additionally comprise electrically conductive traces for transmitting electrical signals. Circuitry platform 950 may be in the form of a thin film, a circuit board or a single electronic die.

[00083] Transparent substrate 964 is similar to transparent substrate

264 described above except that transparent substrate 964 further extends below and across fluid actuator 256 while serving as a chamber layer that also provides fluid ejection chamber 260 (described above). In one implementation, transparent substrate 964 is formed from SU8. In other implementations, transparent substrate 964 may be formed from other materials such as quartz, glass, polymers and the like. In an example implementation, transparent substrate 964 additionally forms ejection orifice 254 (described above). In another example implementation, a separate orifice plate is mounted over portions of substrate 964 to form ejection orifice 254. As with transparent substrate 264, transparent substrate 964 supports lens 266, wherein lens 266 focuses light through transparent substrate 964 and onto the array of sensing elements 263.

[00084] FIG. 15 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 1000. Imaging system 1000 facilitates the capture of two-dimensional images of the ejection face for ejection orifice of a fluid ejection head, wherein such two-dimensional images may be utilized to adjust the operation of head 1020 and/or to control the servicing of head 1020. System 1000 comprises servicer 1002, integrated 0 fluid ejection and imaging head 1020 and support 242 (described above). In the example illustrated, system 1200 relies upon an external separate side illuminator 1232 to illuminate the face of the fluid ejector 224.

[00085] Servicer 1002 comprise a device that is to service or maintain ejection head 1020. In some implementations, servicer 1002 comprises elastomeric wiper blades that are movable into contact with the ejection face of head 1022 white any fluids which may be puddled or collected upon the face of head 1020. In some implementations, servicer 1002 may comprise a spittoon to facilitate purging or clearing of ejection orifices of head 1020. In some implementations, servicer 1002 may comprise a roller or other mechanism for cleaning the face of ejection head 1020. Servicer 1002 may be located to a side of support 242, wherein one or both of head 1020 and servicer 1002 is moved for servicing interaction between servicer 1002 and head 1020.

[00086] Head 1020 is similar to head 220 described above except head 1020 comprises packaging 1040 in place of packaging 240 and additionally comprises actuator 1076 and reflective surface 1078. The remaining components of head 1020 which correspond to components of head 220 are numbered similarly and/or are shown in FIG. 5.

[00087] Packaging 1040 supports fluid ejector 224, two-dimensional rate 228, flat lens 230 and reflective surface 1078. In some implementations packaging 1040 may additionally support actuator 1076 and/or controller 270. Packaging 1040 includes two separate portions that are movable relative to one another. Packaging 1040 comprises fluid ejector portion 1042 and imaging portion 1044. Fluid ejector portion 1042 supports fluid ejector 224 while imaging portion 1044 supports 2D imaging array 228, flat lens 230 and reflective surface 1078. In the example illustrated, imaging portion 1044 is pivotable about a pivot axis 1045 relative to fluid ejector portion 1042.

Imaging portion 1044 is pivotable by an angular extent such that 2D imaging array 228, transparent sub 3231, flat lens 230 and reflective surface 1078 may be retracted or withdrawn away from (above) the plane of the fluid 0 ejection face of fluid ejector 224 to facilitate servicing of the fluid ejection face by servicer 1002.

[00088] Actuator 1076 comprise a device to selectively control the pivot or rotate imaging portion 1044 of packaging 1040 relative to fluid ejector portion 1042. Actuator 1076 may pivot imaging portion 10442 ready head 1020 for servicing by servicer 1002. Actuator 1076 may pivot imaging portion 1044 in response to control signals from controller 270. For example, based upon analysis of 2D images of the ejection face of fluid ejector 224, controller 270 may determine that fluid ejector 224 should be serviced by servicer 1002. Upon such determination, controller 270 may help control signals causing actuator 1076 to pivot imaging portion 1044 to a retracted service position such that 2D imaging array 228, transparent substrate 231 , flat lens 230 and reflective surface 1078 do not interfere with the positioning of servicer 1002 into contact with the ejection face of fluid ejector 224 to perform such servicing. In some implementations, actuator 1076 may comprise an electric motor operably coupled to imaging portion 1044 by a gear train or other transmission. In yet other implementations, actuator 1076 may comprise a hydraulic or pneumatic cylinder-piston assembly, an electric solenoid or other rotary actuators. The use of actuator 1076 and the movable imaging portion 1044 facilitate the servicing of fluid ejector 224 by servicer 1002. Each of the heads and systems in FIGS. 5-14 may likewise include servicer 1002, actuator 1076 and movable imaging portion 1044 to likewise facilitate repositioning of the flat lens and any other portions that might otherwise obstruct the servicing of the ejection face of the fluid ejector 224.

[00089] Reflective surface 1078 facilitates capturing of 2D images of the ejection face of fluid ejector 224. Reflective surface 1078 is provided on a lower face of transparent substrate 231 below flat lens 230. Reflective surface 1078 reflection image of the ejection orifice 254 of fluid ejector 224 through flat lens 230 which focuses image onto 2D imaging array 228.

[00090] In some implementations, reflective surface 1078 is translucent, having a refractive index so as to reflect light through flat lens 230. In some 0 implementations, reflective surface 1078 is provided by the material of transparent substrate 231. In some implementations, reflective surface 1078 is opaque. In some implementations, reflective surface 1078 may be provided by a film coating applied to an underside of transparent substrate 231 below flat lens 230. For example, reflective surface 1078 may comprise a layer of a reflective metal, such as gold, silver, aluminum, chromium, nickel and, in some implementations, titanium dioxide. In some implementations, reflective surface 1078 may comprise a dichroic mirror.

[00091] FIG. 16 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 1100. FIG. 16 illustrates another example by which 2D imaging array 228, transparent substrate 231 , flat lens 230 and reflective surface 1078 may be moved so as to not interfere with the servicing of the fluid ejection head 224 by servicer 1002. System 1100 is similar to system 1000 except that system 1100 comprises packaging 1140 and actuator 1176 in place of packaging 1040 and actuator 1076, respectively.

[00092] Packaging 1140 is similar to packaging 1040 except that imaging portion 1044 of packaging 1140 is translatable relative to fluid ejector portion 1042. In some implementations, imaging portion 1044 is movable along tracks, grooves or other guides relative to fluid ejector portion 1042 in a direction indicated by arrow 1145 so as to be sufficiently with retracted from or vertically above the face of fluid ejector 224 so as to not interfere with the servicing of the face of fluid ejector 224 by servicer 1002. In some implementations, imaging portion 1044 is movable along tracks, grooves or other guides relative to fluid ejector portion 1042 in a direction indicated by 1147 so as to be sufficiently spaced from the face of fluid ejector 224 so should not interfere with the servicing of the face of fluid ejector 224 by servicer 1002.

[00093] Actuator 1176 comprises a device to selectively and controllably translate imaging portion 1044 in direction 1145 and/or direction 1147 for servicing by servicer 1002. Actuator 1176 may translate imaging portion 1044 0 in response to control signals from controller 270. For example, based upon analysis of 2D images of the ejection face of fluid ejector 224, controller 270 may determine that fluid ejector 224 should be serviced by servicer 1002. Upon such determination, controller 270 may output control signals causing actuator 1076 to pivot imaging portion 1044 to a retracted service position such that 2D imaging array 228, transparent substrate 231 , flat lens 230 and reflective surface 1078 do not interfere with the positioning of servicer 1002 into contact with the ejection face of fluid ejector 224 to perform such servicing. In some implementations, actuator 1176 may comprise an electric motor operably coupled to imaging portion 1044 by a gear train or other transmission. In yet other implementations, actuator 1076 may comprise a hydraulic or pneumatic cylinder-piston assembly, an electric solenoid or other linear actuators. The use of actuator 1176 and the movable imaging portion 1044 facilitate the servicing of fluid ejector 224 by servicer 1002. Each of the heads and systems in FIGS. 5-14 may likewise include servicer 1002, actuator 1176 and movable imaging portion 1044 of packaging 1140 to likewise facilitate repositioning of the flat lens and any other portions that might otherwise obstruct the servicing of the ejection face of the fluid ejector 224.

[00094] FIG. 17 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 1200. FIG. 17 illustrates one example of how the face of the fluid ejection head may be illuminated for imaging and how soiling or dirtying of the flat lens and/or 2D imaging array from satellite droplets may be reduced. System 1200 comprises integrated fluid ejection and imaging head 1220 and support 242.

In the example illustrated, system 1200 relies upon the external separate side illuminator 1032 to illuminate the face of fluid ejector 224.

[00095] Integrated fluid ejection and imaging head 1220 comprises fluid ejector 224, 2D imaging array 228 (both of which are described above), spacer 1222, substrate 1224, illuminator 1227, reflective surface 1229, flat lens 1230 and packaging 1240. Spacer 1222 extends between 2D imaging 0 array 228 and substrate 1224, spacing substrate 1224, reflective surface 1229 and flat lens 1230 from 2D imaging array 228 by an air gap 1241.

[00096] Substrate 1224 may be cantilevered from spacer 1222 so as to extend below 2D imaging array 228 and below fluid ejector 224. Substrate 1224 supports reflective surface 1229 and flat lens 1230. In the example illustrated, substrate 1224 is formed from a transparent or translucent material, such as SU8, so as to serve as a light pipe. Substrate 1224 receives light from illuminator 1227 and has a beveled or tapered end 1243 such that the light transmitted through substrate 1224 is redirected at onto the face of fluid ejector 224, facilitating two-dimensional imaging of the ejection face of fluid ejector 224. In the example illustrated, and 1243 utilizes light refraction to illuminate include ejector 224. As shown by broken lines, in some implementations, end 1243 may be coated with a reflective material, such as a layer 1245 of a reflective metal, to further facilitate the reflection of light for illumination of fluid ejector 224 for the imaging of fluid ejector 224. In such an implementation, illuminator 1032 may be omitted depending upon lighting demands for such imaging. In some implementations, illuminator 1227 and the tapered end 1243 may be omitted where sufficient light is provided by illuminator 1032.

[00097] Reflective surface 1229 is similar to reflective surface 1078 described above except that reflective surface 1229 is formed on top of substrate 1224, between substrate 1224 and 2D imaging array 228. In the example illustrated, reflective surface 1229 comprises a layer of a reflective material, such as a reflective metal. In the example illustrated, layer 1229 continuously extends on substrate 1224, between substrate 1224 and spacer 1222. Such an implementation simplifies fabrication. In other implementations, spacer 1222 may be directly connected to substrate 1224 with reflective surface 1229 being formed on substrate 1224 adjacent air gap 1241.

[00098] Lens 1230 is similar to lens 230 described above. Lens 1230 formed on top of reflective surface 1229 so as to focus light reflected from the 0 face of fluid ejector 1224 onto the imaging elements 229 of 2D imaging array 228.

[00099] Packaging 1240 is similar to packaging 240 described above except that packaging 1240 additionally forms a downwardly projecting baffle 1250 projecting between the ejection orifice 254 of fluid ejector 224 and 2D imaging rate 228 and towards flat lens 1230. Baffle 1250 comprises a substantially imperforate wall protecting downwardly below the ejection face of fluid ejector 224 by an extent so us to block satellite droplets which may break off of the primary ejector droplets 225 from impairing the reflection of light by flat lens 1230 towards 2D imaging array 228. At the same time, baffle 1250 downwardly extends by extent so as to continue to permit light reflected from the ejection face or surface of fluid ejector 224 to reflect off of reflective surface 1229, through lens 1230 and onto 2D imaging array 228. This distance by which baffle 1250 extends towards flat lens 1230 or substrate 1224 may vary depending upon the thickness of air gap 1241 , the characteristics of the droplets 225 being ejected in the relative positioning of the very structures of system 1200.

[000100] FIG. 18 is a sectional view schematically illustrated portions of an example integrated fluid ejection and imaging system 1300. System 1300 is similar to system 1200 described above except that 2D imaging array 228 is recessed from the ejection face of fluid ejector 224 (rather than being coplanar as shown in FIG. 17). The additional recessing or spacing of 2D imaging array 228 from flat lens 1230 and reflective surface 1229 provides increase optical magnification (magnification = L2/L3).

[000101] In one implementation, system 1300 has the following example geometries. The spacing d between the ejection orifice and the edge of the transparent substrate 1224, d, is between 50 microns and 5 mm, and nominally 0.2 mm. The printing distance H is between 100 microns and 5 mm, and nominally 2 mm. The magnification provided by the imaging array 228 is between 0.05x and 20x, and nominally 0.3x. The field-of-view of 2D imaging array 228 is between 20 microns and 5 mm, and nominally 0.4 mm. 0

The thickness of the air gap 1241 (the thickness of spacer 1222), hi , is between 20 microns and 3 m , and nominally 1 mm. The working distance, h2, the vertical distance between the ejection face of fluid ejector 2 to 4 and reflective surface 1229, is between 100 microns and 2 mm, and nominally 0.5 mm. In other implementations, system 200 may have other geometric characteristics which may vary depending upon the characteristics of fluid ejector 224, target 246, imaging array 228 and lens 230.

[000102] Although the example shown in FIG. 18 is illustrated as omitting illuminator 1227 and tapered end 1243 on substrate 1224, in other implementations, transparent substrate 1224 may include tapered end 1243 for directing light from illuminator 1227 to further illuminate the ejection face of fluid ejector 224.

[000103] FIG. 19 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 1400 comprising integrated fluid ejection and imaging head 1420. The example system 1400 illustrates how a flat lens may be further protected with an overlying transparent spacer and how soiling or dirtying of the transparent substrate from satellite droplets may be inhibited with a drop deflector. Head 1420 comprises fluid ejector 224, 2D imaging array 228, substrate 1424, reflective surface 1229, flat lens 1230, transparent spacer 1432 and drop deflector 1440.

[000104] Substrate 1424 underlies and supports reflective surface 1229 and flat lens 1230. Substrate 1424 may be transparent, translucent or opaque. Reflective surface 1229 and flat lens 1230 are described above. Transparent spacer 1432 extends between flat lens 1230 and 2D imaging array 1228. Transparent spacer 1432 spaces flat lens 1230 from 2D imaging array 228 and suspends reflective surface 1229 and flat lens 1230 below 2D imaging array 228. In addition, transparent spacer 1432 covers and protects flat lens 1230. In one implementation, transparent spacer 1432 is formed from a transparent material such as glass, SU8 or transparent polymer. 0

[000105] Drop deflector 1440 deflect satellite droplets 1227 away from flat lands 1230 and away from transparent spacer 1432. Satellite droplets 1227 constitute droplets that if split apart or off of the primary ejector droplets 225.

In some implementations, drop deflector 1440 comprises a drop deflection electrode or electrodes that utilize dielectropheresis (DEP) or a corona discharge to deflect or draw satellite droplets 1227 away from flat lens 1230 and transparent spacer 1432.

[000106] FIG. 20 is a sectional view schematically illustrating portions of an example integrated fluid ejection and imaging system 1500 comprising integrated fluid ejection and imaging head 1520. System 1500 is similar to system 1200 described above except that instead of baffle 1250, system 1500 includes drop deflector 1440 (described above). System 1500 illustrates how drop deflector 1440 may be utilized to inhibit soiling or contamination of the reflective surface 1229 and flat lens 1230.

[000107] FIG. 21 is a sectional view schematically illustrated portions of an example integrated fluid ejection and imaging system 1600. System 1600 comprises servicer 1002, support 242 and integrated fluid ejection and imaging head 1620. Head 1620 comprises fluid ejector 224, 2D imaging array 228, packaging 1140, spacer 1222, transparent substrate 1224, illuminator 1227, flat lens 1230, actuator 1076, baffle 1250 and drop deflector 1440, each of which is described above.

[000108] As shown by FIG. 21 , transparent substrate 1224 is partially transmissive, partially reflective so as to reflect light from fluid ejector 224 through flat lens 1230 onto 2D imaging array 228. Transparent substrate 1224 further transmits light from below flat lens 1230 through flat lens 1230 onto 2D imaging array 228. In some implementations, flat lens 1230 focuses light from a single ejector droplet 225 at different points in time through its trajectory. In some implementations, flat lens 1230 focuses the light from an ejector droplet 225 during its flight and an ejection face or ejection orifice of fluid ejector 224. The flat lens combines the wave front of both reflection and transmission focus into a single focus onto 2D imaging array 228. 0

[000109] Controller 270 receives image signals from 2D imaging array 228 and processes such signals to distinguish between images resulting from the light reflected from fluid ejector 224 and images resulting from light passing through transparent substrate 1224. For example, controller 270 may distinguish between such signals based upon a time delay between such signals and an event such as the timing at which a droplet is ejected.

[000110] In some implementations, controller 270 utilizes the images to output a temporal signature indicative of jetting or ejection health. In one implementation, controller 270 sorts pulses with the expected time delay from the ejection event to the time at which an in-flight droplet is imaged. In some implementations, controller 270 may utilize the characteristics of the ejected droplet (such as drop velocity variation, vertical trajectory error, missing drops and the like), its flight characteristics and/or the images of the ejection orifice or surfaces surrounding the ejection orifice to evaluate the health of fluid ejector 224 and whether servicing by servicer 1002 should be initiated or a different ejector should be used. As a result, controller 270 may be part of a smart preventative servicing system that initiates servicing based on imaging sensor demand/response to save fluid such as ink and increase print quality. [000111] Although the present disclosure has been described with reference to example implementations, workers skilled in the art will recognize that changes may be made in form and detail without departing from the disclosure. For example, although different example implementations may have been described as including features providing various benefits, it is contemplated that the described features may be interchanged with one another or alternatively be combined with one another in the described example implementations or in other alternative implementations. Because the technology of the present disclosure is relatively complex, not all changes in the technology are foreseeable. The present disclosure described with reference to the example implementations and set forth in the following claims is manifestly intended to be as broad as possible. For example, unless specifically otherwise noted, the claims reciting a single particular element 0 also encompass a plurality of such particular elements. The terms “first”, “second”, “third” and so on in the claims merely distinguish different elements and, unless otherwise stated, are not to be specifically associated with a particular order or particular numbering of elements in the disclosure.