Patent Publication Number: US-2022227114-A1

Title: Fountain solution imaging and transfer using electrophoresis

Description:
FIELD OF DISCLOSURE 
     The present disclosure is related to marking and printing systems, and more specifically to variable data lithography system using fog development of an electrographic image for creating a fountain solution image. 
     BACKGROUND 
     Offset lithography is a common method of printing today. For the purpose hereof, the terms “printing” and “marking” are interchangeable. In a typical lithographic process a printing plate, which may be a flat plate, the surface of a cylinder, belt and the like, is formed to have image regions formed of hydrophobic and oleophilic material, and non-image regions formed of a hydrophilic material. The image regions are regions corresponding to areas on a final print (i.e., the target substrate) that are occupied by a printing or a marking material such as ink, whereas the non-image regions are regions corresponding to areas on the final print that are not occupied by the marking material. 
     Digital printing is generally understood to refer to systems and methods of variable data lithography, in which images may be varied among consecutively printed images or pages. “Variable data lithography printing,” or “ink-based digital printing,” or “digital offset printing” are terms generally referring to printing of variable image data for producing images on a plurality of image receiving media substrates, the images being changeable with each subsequent rendering of an image on an image receiving media substrate in an image forming process. “Variable data lithographic printing” includes offset printing of ink images generally using specially-formulated lithographic inks, the images being based on digital image data that may vary from image to image, such as, for example, between cycles of an imaging member having a reimageable surface. Examples are disclosed in U.S. Patent Application Publication No. 2012/0103212 A1 (the &#39;212 Publication) published May 3, 2012 based on U.S. patent application Ser. No. 13/095,714, and U.S. Patent Application Publication No. 2012/0103221 A1 (the &#39;221 Publication) also published May 3, 2012 based on U.S. patent application Ser. No. 13/095,778. 
     A variable data lithography (also referred to as digital lithography) printing process usually begins with a fountain solution used to dampen a silicone imaging plate or blanket on an imaging drum. The fountain solution forms a film on the silicone plate that is on the order of about one (1) micron thick. The drum rotates to an exposure station where a high-power laser imager is used to remove the fountain solution at locations where image pixels are to be formed. This forms a fountain solution based latent image. The drum then further rotates to an inking station where lithographic-like ink is brought into contact with the fountain solution based latent image and ink transfers into places where the laser has removed the fountain solution. The ink is usually hydrophobic for better adhesion on the plate and substrate. An ultraviolet (UV) light may be applied so that photo-initiators in the ink may partially cure the ink to prepare it for high efficiency transfer to a print media such as paper. The drum then rotates to a transfer station where the ink is transferred to a print substrate such as paper. The silicone plate is compliant, so an offset blanket is not needed to aid transfer. UV light may be applied to the paper with ink to fully cure the ink on the paper. The ink is on the order of one (1) micron pile height on the paper. 
     The formation of the image on the printing plate/blanket is usually done with imaging modules each using a linear output high power infrared (IR) laser to illuminate a digital light projector (DLP) multi-mirror array, also referred to as the “DMD” (Digital Micromirror Device). The laser provides constant illumination to the mirror array. The mirror array deflects individual mirrors to form the pixels on the image plane to pixel-wise evaporate the fountain solution on the silicone plate to create the fountain solution latent image. 
     Due to the need to evaporate the fountain solution to form the latent image, power consumption of the laser accounts for the majority of total power consumption of the whole system. The laser power that is required to create the digital pattern on the imaging drum via thermal evaporation of the fountain solution to create a latent image is particularly demanding (30 mW per 20 um pixel, ˜500 W in total). The high power laser module adds a significant cost to the system; it also limits the achievable print speed to about five meters per second (5 m/s) and may compromise the lifetime of the exposed components (e.g., micro-mirror array, imaging blanket, plate, or drum). 
     For the reasons stated above, and for other reasons which will become apparent to those skilled in the art upon reading and understanding the present specification, it would be beneficial to increase speed and lower power consumption in variable data lithography systems while improving fountain solution deposition. 
     SUMMARY 
     The following presents a simplified summary in order to provide a basic understanding of some aspects of one or more embodiments or examples of the present teachings. This summary is not an extensive overview, nor is it intended to identify key or critical elements of the present teachings, nor to delineate the scope of the disclosure. Rather, its primary purpose is merely to present one or more concepts in simplified form as a prelude to the detailed description presented later. Additional goals and advantages will become more evident in the description of the figures, the detailed description of the disclosure, and the claims. 
     The foregoing and/or other aspects and utilities embodied in the present disclosure may be achieved by providing an exemplary method for delivering fountain solution onto a target having a charge-retentive surface bearing an electrostatic charged pattern of charged regions thereon. The method includes: a) charging a textured compliant surface layer of a fountain solution transfer member having the textured compliant surface layer wrapped around a conductive layer, the conductive layer have an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, the undercharge regions including discharged and uncharged regions of the charge-retentive surface; b) supplying fountain solution to the textured compliant surface layer, the textured compliant surface layer having lands at a top surface thereof and dimples therein having a volume configured to receive and carry the fountain solution, the textured compliant surface layer having a first depth from the lands to the conductive layer; c) metering fountain solution quantity into the dimples to less than the volume of the dimples leaving gaps in the dimples between the fountain solution and the top surface; d) rotating the lands of the textured compliant surface adjacent the charge retentive surface bearing the electrostatic charged pattern of charged regions thereon; and e) electrophoretically pulling the fountain solution in the dimples across the gaps to wet the charge retentive surface via electrostatic forces and forming a patterned fountain solution latent image on the charge-retentive surface based on the electrostatic charged pattern. 
     According to aspects described herein, another exemplary method for delivering fountain solution onto a target having a charge-retentive surface bearing an electrostatic charged pattern of charged regions thereon. The method includes: a) supplying fountain solution to a textured compliant surface layer of a fountain solution transfer member, the textured compliant surface layer having lands at a top surface thereof and dimples therein having a volume configured to receive and carry the fountain solution, the fountain solution transfer member including the textured compliant surface layer wrapped around a conductive layer with the textured compliant surface layer having a first depth from the lands to the conductive layer, the conductive layer have an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, the undercharge regions including discharged and uncharged regions of the charge-retentive surface; b) metering fountain solution quantity into the dimples to less than the volume of the dimples leaving gaps in the dimples between the fountain solution and the top surface; c) charging the textured compliant surface layer and the fountain solution in the dimples; d) rotating the lands of the textured compliant surface adjacent the charge retentive surface bearing the electrostatic charged pattern of charged regions thereon; and e) electrophoretically pulling the charged fountain solution in the dimples across the gaps to wet the charge retentive surface via electrostatic forces and forming a patterned fountain solution latent image on the charge-retentive surface based on the electrostatic charged pattern. 
     According to aspects illustrated herein, fountain solution delivery device for delivering fountain solution onto a target having a charge-retentive surface bearing an electrostatic charged pattern of charged regions thereon. The delivery device includes a fountain solution transfer member, a metering member, and a charging member. The fountain solution transfer member includes a textured compliant surface layer of a first depth wrapped around a conductive layer, with the textured compliant surface layer having lands at a top surface thereof and dimples therein configured to receive and carry the fountain solution. The conductive layer has an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, with the undercharge regions including discharged and uncharged regions of the charge-retentive surface. Each dimple has a volume. The metering member is in contact with the fountain solution transfer member, and is configured to meter fountain solution quantity in the dimples to less than the volume of the dimples leaving gaps in the dimples between the fountain solution and the top surface. The charging device is configured to charge the textured compliant surface layer of the fountain solution transfer member. The lands of the textured compliant surface are rotated adjacent the charge retentive surface bearing the electrostatic charged pattern of charged regions thereon, and either the charged regions or the undercharge regions of the charge retentive surface electrophoretically pulls the fountain solution in the dimples across the gaps to wet the charge retentive surface and form a patterned fountain solution latent image on the charge-retentive surface based on the electrostatic charged pattern. 
     Exemplary embodiments are described herein. It is envisioned, however, that any system that incorporates features of apparatus and systems described herein are encompassed by the scope and spirit of the exemplary embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various exemplary embodiments of the disclosed apparatuses, mechanisms and methods will be described, in detail, with reference to the following drawings, in which like referenced numerals designate similar or identical elements, and: 
         FIG. 1  illustrates a diagram of a related art ink-based digital printing system; 
         FIG. 2  is a side view partially in cross of a fountain solution delivery device in accordance with examples of the embodiments; 
         FIG. 3  is a side view in cross of a fountain solution transfer member textured compliant surface layer with dimples under-filled with fountain solution in accordance with examples of the embodiments; 
         FIG. 4  is a side view in cross of another fountain solution transfer member textured compliant surface layer with dimples under-filled with fountain solution in accordance with examples of the embodiments; 
         FIG. 5  is a block diagram of a controller with a processor for executing instructions to automatically control components of the digital image forming device and fountain solution delivery device depicted in  FIGS. 1-4 ; 
         FIG. 6  is a flowchart depicting an operation of a fountain solution delivery device in accordance with examples; and 
         FIG. 7  is a flowchart depicting another operation of a fountain solution delivery device in accordance with examples. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Illustrative examples of the devices, systems, and methods disclosed herein are provided below. An embodiment of the devices, systems, and methods may include any one or more, and any combination of, the examples described below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth below. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Accordingly, the exemplary embodiments are intended to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the apparatuses, mechanisms and methods as described herein. 
     We initially point out that description of well-known starting materials, processing techniques, components, equipment and other well-known details may merely be summarized or are omitted so as not to unnecessarily obscure the details of the present disclosure. Thus, where details are otherwise well known, we leave it to the application of the present disclosure to suggest or dictate choices relating to those details. The drawings depict various examples related to embodiments of illustrative methods, apparatus, and systems for inking from an inking member to the reimageable surface of a digital imaging member. 
     When referring to any numerical range of values herein, such ranges are understood to include each and every number and/or fraction between the stated range minimum and maximum. For example, a range of 0.5-6% would expressly include the endpoints 0.5% and 6%, plus all intermediate values of 0.6%, 0.7%, and 0.9%, all the way up to and including 5.95%, 5.97%, and 5.99%. The same applies to each other numerical property and/or elemental range set forth herein, unless the context clearly dictates otherwise. 
     The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (for example, it includes at least the degree of error associated with the measurement of the particular quantity). When used with a specific value, it should also be considered as disclosing that value. For example, the term “about 2” also discloses the value “2” and the range “from about 2 to about 4” also discloses the range “from 2 to 4.” 
     The term “controller” or “control system” is used herein generally to describe various apparatus such as a computing device relating to the operation of one or more device that directs or regulates a process or machine. A controller can be implemented in numerous ways (e.g., such as with dedicated hardware) to perform various functions discussed herein. A “processor” is one example of a controller which employs one or more microprocessors that may be programmed using software (e.g., microcode) to perform various functions discussed herein. A controller may be implemented with or without employing a processor, and also may be implemented as a combination of dedicated hardware to perform some functions and a processor (e.g., one or more programmed microprocessors and associated circuitry) to perform other functions. Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, conventional microprocessors, application specific integrated circuits (ASIC s), and field-programmable gate arrays (FPGAs). 
     The terms “media”, “print media”, “print substrate” and “print sheet” generally refers to a usually flexible physical sheet of paper, polymer, Mylar material, plastic, or other suitable physical print media substrate, sheets, webs, etc., for images, whether precut or web fed. The listed terms “media”, “print media”, “print substrate” and “print sheet” may also include woven fabrics, non-woven fabrics, metal films, and foils, as readily understood by a skilled artisan. 
     The term “image forming device”, “printing device” or “printing system” as used herein may refer to a digital copier or printer, scanner, image printing machine, xerographic device, electrostatographic device, digital production press, document processing system, image reproduction machine, bookmaking machine, facsimile machine, multi-function machine, or generally an apparatus useful in performing a print process or the like and can include several marking engines, feed mechanism, scanning assembly as well as other print media processing units, such as paper feeders, finishers, and the like. A “printing system” may handle sheets, webs, substrates, and the like. A printing system can place marks on any surface, and the like, and is any machine that reads marks on input sheets; or any combination of such machines. 
     The term “fountain solution” or “dampening fluid” refers to dampening fluid that may coat or cover a surface of a structure (e.g., imaging member, transfer roll) of an image forming device to affect connection of a marking material (e.g., ink, toner, pigmented or dyed particles or fluid) to the surface. The fountain solution may include water optionally with small amounts of additives (e.g., isopropyl alcohol, ethanol) added to reduce surface tension as well as to lower evaporation energy necessary to support subsequent laser patterning. Low surface energy solvents, for example volatile silicone oils, can also serve as fountain solutions. Fountain solutions may also include wetting surfactants, such as silicone glycol copolymers. The fountain solution may be non-aqueous including, for example, silicone fluids (such as D3, D4, D5, OS10, OS20, OS30 and the like), Isopar fluids, and polyfluorinated ether or fluorinated silicone fluid. 
     The term “aerosol” refers to a suspension of solid and/or liquid particles in a gas. An aerosol may include both the particles and the suspending gas, which may be air, another gas or mixture thereof. The solids and/or liquid particles are sufficiently large for sedimentation, for example, as fountain solution on an imaging member surface. For example, solid or liquid particles may be greater than 0.1 micron, less than 5 microns, between about 0.5 and 2 microns and about 1 micron in diameter. 
     Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. For example, “a plurality of stations” may include two or more stations. The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. 
       FIG. 1  depicts an exemplary related art ink-based digital image forming apparatus  10  for variable data lithography including fog development of a charged fountain solution aerosol that forms a latent digital image created electrographically. The latent digital image is transferred to an inking blanket  12  of a transfer member  14  (e.g., roller, cylinder, drum) downstream an imaging member  16  for subsequent printing of an associated ink image  18  onto a print substrate  20 . The imaging member  16  shown in  FIG. 1  is a drum, but this exemplary depiction should not be read in a manner that precludes the imaging member  16  being a blanket, a belt, or of another known configuration. The image forming apparatus  10  includes the rotatable imaging member  16  having an arbitrarily reimageable surface  22  as different images can be created on the surface layer. In examples, the surface  22  is a charge-retentive surface such as but not limited to a photoreceptor surface or a dielectric surface. The reimageable charge-retentive surface  22  may be part of the drum or formed over a structural mounting layer that may be, for example, a cylindrical core, or one or more structural layers over a cylindrical core. The reimageable charge-retentive surface may be formed of a relatively thin layer over the mounting layer, a thickness of the relatively thin layer being selected to balance charge retaining performance, durability and manufacturability. The imaging member  16  is surrounded by an imaging station  24  configured to form an electrostatic charged pattern of a latent image on the imaging member surface  22 , and an aerosol development device  26  that provides a fog of charged fountain solution aerosol particles that are attracted to the electrostatic charged pattern. 
     According to examples, fountain solution latent images  28  are created (e.g., xerographically, ionographically) on imaging member  16  and transferred to the inking blanket  12  for further processing. At the imaging station  24 , a charging device  30  charges the imaging member surface  22 , for example by corona discharge from a high voltage power source via a conductor of the charging device adjacent the charge-retentive imaging member surface  22 . In electrography or xerography an imager  32  having a low power light source (e.g., a laser with a conventional ROS scanner, LED bar) selectively discharges select portions or pixels of the surface  22  according to image data to generate an electrostatic charged pattern  34  disposed on the surface of the imaging member  20 . In ionography the imager  32  includes an image projection head for projecting ion beams, i.e., ions of a given polarity, onto the charge-retentive surface  22  after the surface is charged by the charging device  30 . The surface  22  shown could be a photoreceptor, but when the application is ionographically created, an insulating surface could be used to create the charge image. 
     The aerosol development device  26  presents a charged patterned uniform layer of fountain solution (e.g., silicone fluids, such as D4, D5, Isopar G, Isopar H, Dowsil OS20, Dowsil OS30, L5; water/IPA mixtures, hydrophilic fluids, and mixtures thereof) aerosol particles  36  in solid or liquid particle form onto the surface  22  of the imaging member  16 . The fountain solution aerosol particles  36  are configured to adhere to portions of the imaging member surface  22  according to the electrostatic charged pattern  34  developed thereon by imager  32 . In examples, charged fountain solution aerosol particles  36  of opposite polarity of the imaging member surface  22  are deposited onto the electrostatic charged pattern  34 , forming a fountain solution latent image  28  on the imaging member surface. In other examples, charged fountain solution aerosol particles  36  of the same polarity as the imaging member surface  22  would be deposited on the neutral pixels thereof. 
     The aerosol development device  26  atomizes and charges fountain solution  38  into charged fountain solution aerosol particles  36  that enter an inlet port  40 . In examples, a pump may supply fountain solution from a container housing the fountain solution to an aerosol generator (e.g., a nebulizer) at a steady, controlled rate. The fountain solution may contain charge control agents (e.g., surfactants, polymer solution, salts), to assist particle charging, as well understood by a skilled artisan. The aerosol development device  26  further includes a manifold having walls  62  defining a chamber  44  and a radially enlarged region  46  near the imaging member surface  22  where a fog of charged fountain solution aerosol particles  36  may carry the atomized fountain solution to the electrostatic charged pattern  34  on the surface of imaging member  16 . 
     A carrier gas such as nitrogen, added in a predetermined amount, may be introduced into the developer unit chamber  44  via inlet port  40  to carry the atomized fountain solution aerosol particles  36  to the surface  22  of imaging member  16  as a gas mixture, where they may be attracted to the electrostatic charged pattern  34  and bond to the charge-retentive reimageable surface  22  and form a fountain solution latent image  28 . The gas mixture transporting the atomized fountain solution aerosol particles includes the carrier gas and a controlled partial pressure of fountain solution. This partial pressure of fountain solution may solely originate from evaporated fountain solution or a controlled additional vaporized fountain solution. An increase in the partial pressure of the fountain solution will slow down the evaporation from the fountain solution droplets. The partial pressure may be modified, for example, by the controller adding vaporized fountain solution to the gas mixture, as well understood by a skilled artisan. 
     The surface charge density (created by charging device  30 ) of the latent image attracts a volume of fountain solution aerosol particles  36  until the surface charge is optionally neutralized or partially neutralized by the fog charged aerosol. Adhesion forces with the imaging member  16  and each other will cause the aerosol particles to remain on the surface  22  of the imaging member. 
     Aerosol particles  36  do not bond to the surface  22  of imaging member  16  where no latent image charge resides. The aerosol particles  36  can also be electrostatically repelled from uncharged regions of the electrostatic charged pattern  34 , for example, via voltage applied to walls of the development device  26 . Aerosol particles  36  that do not bond to the imaging member surface  22  may exit the developer unit  20  via outlet port  42  and flow back to the fountain solution container. A vapor vacuum or air knife (not shown) may be positioned adjacent the downstream side of the radially enlarged region  46  near the outlet port  42  to collect unattached aerosol particles and thus avoid leakage of fountain solution into the environment. Reclaimed fountain solution particles can also be condensed and filtered as needed for reuse as understood by a skilled artisan to help minimize the overall use of fountain solution by the image forming device  10 . 
     The transfer member  14  may be configured to form a fountain solution image transfer nip  48  with the imaging member  16 . A fountain solution image produced by the developer unit  26  and imaging station  24  on the surface  22  of the imaging member  16  is transferred to the inking blanket  12  of the transfer member  14  under pressure at the loading nip  48 . In particular, a light pressure (e.g., a few pounds, greater than 0.1 lbs., less than 10 lbs., about 1-4 lbs.) may be applied between the surface of the inking blanket  12  and the imaging member surface  22 . At the fountain solution transfer nip  48 , the fountain solution latent image  28  splits as it leaves the nip, and transfers a split layer of the fountain solution latent image, referred to as the transferred fountain solution latent image  50 , to the transfer member surface (i.e., inking blanket  12 ). The amount of fountain solution transferred may be adjusted by contact pressure adjustments of nip  48 . For example, a split fountain solution latent image  50  of about one (1) micrometer or less may be transferred to the inking blanket surface. Like the imaging member  16 , the transfer member  14  may be electrically biased to enhance loading of the dampening fluid latent image at the loading nip  48 . 
     After transfer of the fountain solution latent image from the imaging member  16 , the imaging member  16  may be cleaned in preparation for a new cycle by removing dampening fluid and solid particles from the surface at a cleaning station  52 . Various methods for cleaning the imaging member surface  22  may be used, for example an air knife and/or sponge, as well understood by a skilled artisan. 
     After the fountain solution latent image  50  is transferred to the transfer member  14 , ink from an inker  54  is applied to the inking blanket  12  to form an ink pattern or image  18 . The inker  54  is positioned downstream fountain solution transfer nip  48  to apply a uniform layer of ink over the transferred fountain solution latent image  50  and the inking blanket  12 . While not being limited to a particular theory, the ink pattern or image  18  may be a negative of or may correspond to the fountain solution pattern. For example, the inker  54  may deposit the ink to the evaporated pattern representing the imaged portions of the reimageable surface  26 , while ink deposited on the unformatted portions of the fountain solution will not adhere based on a hydrophobic and/or oleophobic nature of those portions. The ink image  18  may be transferred to print media or substrate  20  at an ink image transfer nip  56  formed by the transfer member  14  and a substrate transport roll  58 . The substrate transport roll  58  may urge the print substrate  20  against the transfer member surface, or inking blanket  12 , to facilitate contact transfer of the ink image  18  from the transfer member  14  to the print substrate. 
     After transfer of the ink image  18  from the transfer member  14  to the print media  20 , residual ink may be removed by a cleaning device  60 . This residual ink removal is most preferably undertaken without scraping or wearing the imageable surface of the imaging blanket  12 . Removal of such remaining fluid residue may be accomplished through use of some form of cleaning device  60  adjacent the imaging blanket  12  between the ink image transfer nip  56  and the fountain solution transfer nip  48 . Such a cleaning device  20  may include at least a first cleaning member such as a sticky or tacky roller in physical contact with the imaging blanket surface, with the sticky or tacky roller removing residual fluid materials (e.g., ink, fountain solution) from the surface. The sticky or tacky roller may then be brought into contact with a smooth roller (not shown) to which the residual fluids may be transferred from the sticky or tacky member, the fluids being subsequently stripped from the smooth roller by, for example, a doctor blade or other like device and collected as waste. 
     It is understood that the cleaning device  60  is one of numerous types of cleaning devices and that other cleaning devices designed to remove residual ink/fountain solution from the surface of imaging blanket  12  are considered within the scope of the embodiments. For example, the cleaning device could include at least one roller, brush, web, belt, tacky roller, buffing wheel, etc., as well understood by a skilled artisan. It is also understood that the cleaning device  60  may be more sophisticated or aggressive at removing residual fluids from imaging blanket  12  that the cleaning station  52  is at removing fountain solution from the surface  22  of the imaging member  16 . Cleaning station  52  is not concerned with removing residual ink, and merely is designed to remove fountain solution and associated contaminates from the surface  22 . 
     The exemplary ink-based digital image forming devices and operations thereof may be controlled by a controller  70  in communication with the image forming devices and parts thereof. For example, the controller  70  may control the imaging station  24  to create electrostatic charged patterns of latent images on the imaging member surface  22 . Further, the controller  70  may control the aerosol development device  26  or other aerosol development devices discussed in greater detail below to provides the fog of charged fountain solution aerosol particles that are attracted to the electrostatic charged pattern. The controller  70  may be embodied within devices such as a desktop computer, a laptop computer, a handheld computer, an embedded processor, a handheld communication device, or another type of computing device, or the like. The controller  70  may include a memory, a processor, input/output devices, a display and a bus. The bus may permit communication and transfer of signals among the components of the controller  70  or computing device, as will be described in greater detail below. 
       FIGS. 2-4  depict additional approaches for delivering fountain solution  38  via electrophoresis onto a target (e.g., imaging member  16 ) having the charge-retentive surface  22  bearing electrostatic charged pattern  34 . In lieu of the aerosol development device  26 , examples include a fountain solution delivery device  100  having a fountain solution transfer member  102  a metering member  104  and a charging device  105  as can be seen by example in  FIG. 2 . The fountain solution delivery device described in greater detail below present a charged patterned layer of fountain solution  38  (e.g., silicone fluids, such as D4, D5, Isopar G, Isopar H, Dowsil OS20, Dowsil OS30, L5; water/IPA mixtures, hydrophilic fluids, and mixtures thereof) onto surface  22  of imaging member  16 . The fountain solution  38  wets portions of the imaging member surface  22  and forms a latent image according to the electrostatic charged pattern  34  developed thereon by imager  32 . Accordingly the fountain solution delivery devices  100  may replace the aerosol development device  26  described above, and may associate with the controller  70  in similar manner. However, the approach to wetting the imaging member surface  22  by electrophoresis does not require fog development, and fountain solution volume and thickness on the charge-retentive surface may be better controlled. 
     The fountain solution delivery device  100  may be part of an imaging system useful for printing with the ink-based digital image forming device  10  ( FIG. 1 ) having rotatable imaging member  16  with a charge-retentive reimageable surface  22  bearing an electrostatic charged pattern  34  and a rotatable inking blanket  12  downstream the imaging member. The rotatable inking blanket  12  (or belt) has a surface in rolling communication with the charge-retentive surface  22  and may be conformable to accept the patterned fountain solution latent image  28  and transfer an ink image  18  corresponding to the electrostatic charged pattern  34  to a substrate  20 . The inking blanket  12  may include, for example, hydrophobic polymers such as silicones, partially or fully fluorinated fluorosilicones and FKM fluoroelastomers. Other materials may be employed, including blends of polyurethanes, fluorocarbons, polymer catalysts, platinum catalyst, hydrosilyation catalyst, etc. The surface may be configured to conform to a print substrate on which an ink image is printed. To provide effective wetting of fountain solutions such as water-based dampening fluid, the silicone surface need not be hydrophilic, but may be hydrophobic. The inking blanket  12  may have high electrical resistivity and finite conductivity to avoid charge buildup on the blanket. 
     Referring to  FIGS. 2-4 , the fountain solution transfer member  102  has a textured compliant surface layer  106  wrapped around a conductive (e.g., metal, aluminum, steel, silver) layer  108 . The textured compliant surface layer  106  has a thickness or depth (e.g., less than 100 microns, less than 50 microns, about 5-20 microns) and is textured with lands  110  at a top surface thereof and dimples  112  or pits therein. The dimples have a volume designed to receive and carry the fountain solution  38  to the charge retentive surface  22 . The fountain solution transfer member  102  may refer to a textured roll having a pitted or textured surface layer with dimples in a matrix of lands, for example like anilox cells in the surface of an anilox roll. The transfer member  102  may be cylindrical, ellipsoidal, elliptical cylindrical, oblong cylindrical, spherical, oval cylindrical, parabolic cylindrical, hyperbolic cylindrical or any combination thereof. 
     While not being limited to a particular configuration, the transfer member  102  may be similar in appearance to an anilox roll, but its surface layer  106  is compliant. The conformable textured surface layer  106  is formed over the conductive structural mounting layer  108  that may be, for example, a cylindrical, ellipsoidal or oblong cylindrical core  114 , or one or more structural layers over the core. In examples, the conductive layer  108  may surround the core  114  under the textured surface layer. The core may be solid, rigid, compliant, hollow or some combination thereof, with hollowed core designed to allow fluid therein. The conductive layer having an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, the undercharge regions including discharged and uncharged regions of the charge-retentive surface. 
     In examples, the textured surface layer  106  may be conformable (e.g., including silicone, PDMS, plastic, rubber), and may be an electrical insulator. The textured surface may be formed of a relatively thin layer (e.g., less than 100 microns, less than 50 microns, about 5-20 microns) over the mounting layer, a thickness of the relatively thin layer being selected to balance fountain solution particle transfer, durability and manufacturability. While not being limited to a particular theory, the dimples or anilox cells may be formed by embossment, etching, engraving, die casting, molding, photo patterning, laser ablation or other approaches understood by a skilled artisan. The dimples are not limited to a particular size and may have a diameter and/or depth of less than 100 microns, 1-10 microns, 2-5 microns or about 4 microns. The dimples may be deep enough to allow a layer of fountain solution  38  and a gap between the fountain solution and top surface of the lands, as will be described in greater detail below. Further, the dimples are not limited by shape, and may be hemispherical, cylindrical, semi-ellipsoidal, prism shaped, cone shaped, trapezoid prism, hexagonal, pyramidal, tetrahedronal, cuboidal, etc. 
     Fountain solution  38  is deposited uniformly within the dimples  112 . For example, the fountain solution may be deposited into the dimples by any of several ways as understood by a skilled artisan, including by vapor condensation, doctor blading or roller application and metering.  FIG. 2  illustrates an example with fountain solution  38  from a fountain solution supply (e.g., reservoir  116  defined by a roller  118  and transfer member  102 ) deposited into the dimples. The filling volume of the deposited fountain solution may be controlled to less than the full volume of the dimples  112 , leaving a gap between the metered fountain solution and the top surface. In examples the filling volume may be controlled parametrically as understood by a skilled artisan. In examples the filling volume may be controlled via a self-limiting mode, e.g. by compressing the compliant surface layer lands  110  in the presence of the fountain solution  38  and allowing land expansion upon leaving the filling nip  120 . 
     Without being limited to a particular theory, excess fountain solution  38  may be metered from the dimples by the metering member  104  (e.g, roller, doctor blade) pressing into the textured compliant surface layer  106  at nip  120  therebetween. Pressing with the metering member  104  into the dimples  112  filled with fountain solution may deform the compliant surface layer and reduce the volume of the dimples while also removing fountain solution from lands  110 . As the compliant surface layer continues to rotate towards the imaging member  16  and beyond the nip  120 , the surface layer expands and the volume of the dimples returns to its pre-compressed volume. This expansion creates gaps  122  ( FIGS. 3, 4 ) in the dimples between the fountain solution  38  and the top surface lands  110 . It is understood that other approaches are available to meter excess fountain solution from the dimples to create the gaps  122  ( FIGS. 3, 4 ). For example, metering into the dimples with a metering member roller or blade that is more compliant than the textured top layer would also underfill the dimples as the more compliant metering member deforms into the dimples. As another example, if the textured top layer is relatively rigid, but resides on a relatively compliant core under layer, a compliant metering member roller or blade may be used to press into the dimples and remove excess fountain solution  38  before exiting and leaving the gaps. 
     The charging device  105  is configured to charge the textured compliant surface layer  106  of the fountain solution transfer member and/or fountain solution in the dimples  112 . In examples, the charging device  105  may be positioned adjacent the fountain solution transfer member  102  before fountain solution is supplied to the textured compliant surface layer  106 , as shown generally by charging device  105 A, and charges the surface layer. In other examples, the charging device  105  may be positioned adjacent the fountain solution transfer member  102  after fountain solution is supplied to the textured compliant surface layer  106 , as shown generally by charging device  105 B. When positioned after fountain solution is supplied to the textured compliant surface layer, the charging device  15  may drive a flux of ions through the fountain solution to charge the fountain solution in the dimples and the surface layer under the fountain solution. 
     It is understood that the examples are not limited by the manner that the textured compliant surface layer  106  and/or the fountain solution  38  are charged by the charging device  105 . In examples, the textured compliant surface layer  106  and/or the fountain solution  38  may be charged by corona charging or discharge from a corotron, scorotron, or other conductor carrying a voltage as readily understood by a skilled artisan. In examples, including the example illustrated in  FIG. 3 , the fountain solution  38  may be charged by charging device  105 A charging the textured compliant surface layer  106  before filling the dimples  114  with fountain solution. In other examples, including the example illustrated in  FIG. 4 , the fountain solution  38  may be charged by charging device  105 B after the dimples  114  are filled or under-filled with the fountain solution. In yet other examples, the charging device  105  may convert the fountain solution stored in the fountain solution reservoir  116  into charged particles (e.g. micelles) by injecting charge into the stored fountain solution that is metered into the dimples  114 , as understood by a skilled artisan. 
       FIG. 3  depicts an exemplary fountain solution transfer member  102  textured compliant surface layer  106  with dimples  112  under-filled with fountain solution  38  and lands  110  adjacent the charge retentive reimageable surface  22  of imaging member  16 . The compliant surface layer may be formed by casting the layer (e.g., including silicone, PDMS, plastic, rubber) on a topographically patterned master, curing the layer and separating it from the patterned master. In examples the surface layer  106  may have an outer layer of an epoxy-based negative photoresist (e.g., SU-8) formed as a generally uniform thin layer (e.g., less than 20 microns, between .1 and 10 microns, about 1-2 microns). The epoxy-based negative photoresist may be patterned using standard photolithographic approaches to provide dimples  112 , as understood by a skilled artisan. 
     A back side of the compliant surface layer may be bonded to a metalized or otherwise conductive support layer  108 . The conductive layer  108  may surround the core  114  under the textured surface layer. The core may be solid, rigid, compliant, hollow or some combination thereof. For example the core  114  may include a compliant outer layer  124  under the conductive layer  108 , and a second layer  126  under the compliant outer layer that is more rigid than the compliant outer layer. The core  114  may also include a hollow aperture  128  to allow fluid therein as well understood by a skilled artisan. While not being limited to a particular configuration, the dimples shown in the example depicted in  FIG. 3  may be less than 10 or 5 microns, and about 1-4 microns in diameter and depth. 
     The compliant surface layer  106  may be rotated adjacent (e.g., in contact, next to, near, less than 5 microns, about ˜0-2 microns) the charge retentive surface  22  during operation to wet the charge retentive surface at the electrostatic charged pattern  34  and form a patterned fountain solution latent image  28  on the charge-retentive surface based on the electrostatic charged pattern.  FIG. 3  shows the compliant surface layer  106  adjacent the charge retentive surface  22 , with the backside of the fountain solution charged by the charging device  105 A charging the dimples  112  before the dimples are filled with the fountain solution. It is understood that this is by example, and the compliant surface layer  106  may also touch or nearly touch the charge retentive surface when adjacent to the charged retentive surface  22  for the fountain solution  38  to wet the charge retentive surface by electrophoresis. It is also understood that while the compliant surface layer  106  is shown under the charge retentive surface  22  in examples ( FIGS. 3, 4 ) and side-by-side in another example ( FIG. 2 ), wetting of the charge retentive surface by the fountain solution in the dimples  112  is not limited to a particular orientation between the charge retentive surface and textured compliant surface layer. 
     In operation, the compliant surface layer  106  and charge retentive reimageable surface  22  rotate adjacent each other. When the charged regions of the electrostatic charged pattern are adjacent the charged fountain solution and under-filled dimples  112 , the fountain solution charge is repelled in the downward directed field under discharged (or uncharged) regions (e.g., −100V) of the charge-retentive reimageable surface and is attracted to the charge-retentive reimageable surface in the regions of charged pixels (e.g., −700V). In other words, electrostatic forces drag the fountain solution  38  in the under-filled dimples across gaps  122  to the charged pixel surface bearing the electrostatic charged pattern and away from the discharged (or uncharged) pixel regions, which are not part of the electrostatic charged pattern. The fountain solution  38  electrophoretically pulled across the gaps  122  wet the charge retentive surface at the electrostatic charged pattern and form a patterned fountain solution latent image  28  on the charge-retentive surface based on the electrostatic charged pattern. 
     The charge retentive reimageable surface may be a photoreceptor generally understood to have fully charged regions at the electrostatic charged pattern regions and undercharged (e.g., discharged) regions where a discharged charge level may typically not be zero residual charge, but maybe about 10-20%, or less than 20% of the charged region. For ionographic surfaces of the charge retentive reimageable surface  22 , undercharged (e.g., uncharged) regions may have very nearly zero charge. 
       FIG. 4  depicts another example of electrophoresis with the compliant surface layer  106  adjacent the charge retentive surface  22 . In this example, the compliant surface layer  106  and charge retentive surface  22  are substantially similar to the compliant surface layer and charge retentive surface depicted in  FIG. 3 , however the front side of the fountain solution in the under-filled dimples are charged by the charging device  105 B after the dimples are filled with the fountain solution. 
     In operation with the example shown in  FIG. 4 , as in  FIG. 3 , the compliant surface layer  106  and charge retentive reimageable surface  22  rotate adjacent each other such that when the charged regions of the electrostatic charged pattern are adjacent the charged fountain solution and under-filled dimples  112 , the fountain solution charge is repelled in the downward directed field under discharged (or uncharged) regions (e.g., −100V) of the charge-retentive reimageable surface and is attracted to the charge-retentive reimageable surface in the regions of charged pixels (e.g., −700V). That is, electrostatic forces drag the fountain solution  38  in the under-filled dimples across gaps  122  to the charged pixel surface bearing the electrostatic charged pattern and away from the discharged (or uncharged) pixel regions, which are not part of the electrostatic charged pattern. The fountain solution  38  electrophoretically pulled across the gaps  122  wet the charge retentive surface at the electrostatic charged pattern and form a patterned fountain solution latent image  28  on the charge-retentive surface based on the electrostatic charged pattern. 
     In examples, the textured compliant surface layer dimples  112  reside adjacent the charged regions of the electrostatic charged pattern  34  for a time long enough to wet the charged pixels in the charged regions to a desired volume or thickness of fountain solution coverage (e.g., less than 500 microns, about 20-200 microns, about 70-130 microns). The resident time for the charged regions and dimples to remain proximate to electrophoretically transfer fountain solution from the dimples to the surface  22  to form a latent image having sufficient thickness may be varied by control variables such as rotational speed, contact pressure—and thus nip length and contact dwell time, and charge densities on the charge retentive reimageable surface and the textured compliant surface layer  106 , as understood by a skilled artisan. 
     In examples including the depictions of  FIGS. 3 and 4 , where the conductive layer  108  has an electric potential (e.g., −400V, between −100V and −700V) between electric potentials of the charged regions (e.g., −700V) of the electrostatic charged pattern and undercharged regions (e.g., −100V) of the charge-retentive surface other than the charged regions, the charged fountain solution  38  in the dimples  112  may all be under electrophoresis forces regardless of whether the fountain solution is adjacent charged or undercharged regions. In examples, electrophoresis may occur as the charged ions surrounded by dipoles in the insulating fountain solution is dragged by the electric field, which viscously drags charged or uncharged regions of the dielectric fountain solution in the dimples with them. 
     After the fountain solution latent image  28  is developed on the charge retentive reimageable surface  22 , the imaging member  16  is brought in rolling contact with the inked image transfer member  14  at the fountain solution transfer nip  48  ( FIG. 1 ), where the fountain solution latent image splits to supply the inking blanket  12  with the desired latent image coverage. The latent image may be a positive image or negative image and may be transferred from the charge-retentive surface to a transfer member inking blanket for forming an inked image thereon based on the electrostatic charged pattern. Ink is applied to the latent image on the inking blanket, resulting in an ink image  18  that may be transferred to print media or substrate  20  at an ink image transfer nip  56 , as described above. 
       FIG. 5  illustrates a block diagram of the controller  70  for executing instructions to automatically control the ink-based digital image forming device  10 , fountain solution delivery devices  100  and components thereof. The exemplary controller  70  may provide input to or be a component of a controller for executing image formation methods in a system such as that depicted in  FIGS. 1-4  and described in greater detail below in  FIGS. 6 and 7 . 
     The exemplary controller  70  may include an operating interface  72  by which a user may communicate with the exemplary control system. The operating interface  72  may be a locally-accessible user interface associated with the digital image forming device  10  and fountain solution delivery devices  100 . The operating interface  72  may be configured as one or more conventional mechanism common to controllers and/or computing devices that may permit a user to input information to the exemplary controller  70 . The operating interface  72  may include, for example, a conventional keyboard, a touchscreen with “soft” buttons or with various components for use with a compatible stylus, a microphone by which a user may provide oral commands to the exemplary controller  70  to be “translated” by a voice recognition program, or other like device by which a user may communicate specific operating instructions to the exemplary controller. The operating interface  72  may be a part or a function of a graphical user interface (GUI) mounted on, integral to, or associated with, the digital image forming device  10  and fountain solution delivery devices  100  with which the exemplary controller  70  is associated. 
     The exemplary controller  70  may include one or more local processors  74  for individually operating the exemplary controller  70  and for carrying into effect control and operating functions for image formation onto a print substrate  20 , including but not limited to forming an electrostatic charged pattern  34  on the charge retentive reimageable surface  22 , metering fountain solution in dimples  112 , charging fountain solution, transferring charged metered fountain solution onto the charge retentive reimageable surface  22  to form a fountain solution latent image  28 , transferring the latent image from the imaging member  16  to an inking blanket  12  surface of an inked image transfer member  14 , depositing a layer of ink over the latent image to form an ink image  18  and transferring the ink image from the inking blanket to print substrate  20 . Processor(s)  74  may include at least one conventional processor or microprocessor that interprets and executes instructions to direct specific functioning of the exemplary controller  70 , and control of the image forming process with the exemplary controller. 
     The exemplary controller  70  may include one or more data storage devices  76 . Such data storage device(s)  76  may be used to store data or operating programs to be used by the exemplary controller  70 , and specifically the processor(s)  74 . Data storage device(s)  76  may be used to store information regarding, for example, a current image for patterning by the imaging station  24 , desired and actual fountain solution metering transfer parameters, charge density of the charge-retentive surface  22  and conductive layer  108 , and digital image information with which the digital image forming device  10  and fountain solution delivery devices  100  are associated. 
     The data storage device(s)  76  may include a random access memory (RAM) or another type of dynamic storage device that is capable of storing updatable database information, and for separately storing instructions for execution of image forming operations by, for example, processor(s)  74 . Data storage device(s)  76  may also include a read-only memory (ROM), which may include a conventional ROM device or another type of static storage device that stores static information and instructions for processor(s)  74 . Further, the data storage device(s)  76  may be integral to the exemplary controller  70 , or may be provided external to, and in wired or wireless communication with, the exemplary controller  70 , including as cloud-based data storage components. 
     The data storage device(s)  76  may include non-transitory machine-readable storage medium to store the device queue manager logic persistently. While a non-transitory machine-readable storage medium is may be discussed as a single medium, the term “machine-readable storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store one or more sets of instructions. The term “machine-readable storage medium” shall also be taken to include any medium that is capable of storing or encoding a set of instruction for execution by the controller  70  and that causes the digital image forming device  10  and fountain solution delivery devices  100  to perform any one or more of the methodologies of the present invention. The term “machine-readable storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, and optical and magnetic media. 
     The exemplary controller  70  may include at least one data output/display device  78 , which may be configured as one or more conventional mechanisms that output information to a user, including, but not limited to, a display screen on a GUI of the digital image forming device  10 , fountain solution delivery devices  100 , and/or associated image forming devices with which the exemplary controller  70  may be associated. The data output/display device  78  may be used to indicate to a user a status of the digital image forming device  10  with which the exemplary controller  70  may be associated including an operation of one or more individually controlled components at one or more of a plurality of separate image processing stations or subsystems associated with the image forming device. 
     The exemplary controller  70  may include one or more separate external communication interfaces  80  by which the exemplary controller  70  may communicate with components that may be external to the exemplary control system such as a temperature sensor, printer or other image forming device. At least one of the external communication interfaces  80  may be configured as an input port to support connecting an external CAD/CAM device storing modeling information for execution of the control functions in the image formation operations. Any suitable data connection to provide wired or wireless communication between the exemplary controller  70  and external and/or associated components is contemplated to be encompassed by the depicted external communication interface  80 . 
     The exemplary controller  70  may include an image forming control device  82  that may be used to control the image forming process to render ink images on the print substrate  20 . For example, the image forming control device  82  may: control the imaging station  24  to form an electrostatic charged pattern  34  on the charge retentive reimageable surface  22 , control the fountain solution delivery devices  100  to form fountain solution latent images including fountain solution metering and transfer volume. The image forming control device  82  may operate as a part or a function of the processor  74  coupled to one or more of the data storage devices  76 , the digital image forming device  10  and fountain solution delivery devices  100 , or may operate as a separate stand-alone component module or circuit in the exemplary controller  70 . 
     All of the various components of the exemplary controller  70 , as depicted in  FIG. 5 , may be connected internally, and to the digital image forming device  10 , fountain solution delivery devices  100 , and/or components thereof, by one or more data/control busses  84 . These data/control busses  84  may provide wired or wireless communication between the various components of the image forming device  10 , fountain solution delivery devices  100 , and any associated image forming apparatus, whether all of those components are housed integrally in, or are otherwise external and connected to image forming devices with which the exemplary controller  70  may be associated. 
     It should be appreciated that, although depicted in  FIG. 5  as an integral unit, the various disclosed elements of the exemplary controller  70  may be arranged in any combination of sub-systems as individual components or combinations of components, integral to a single unit, or external to, and in wired or wireless communication with the single unit of the exemplary control system. In other words, no specific configuration as an integral unit or as a support unit is to be implied by the depiction in  FIG. 5 . Further, although depicted as individual units for ease of understanding of the details provided in this disclosure regarding the exemplary controller  70 , it should be understood that the described functions of any of the individually-depicted components, and particularly each of the depicted control devices, may be undertaken, for example, by one or more processors  74  connected to, and in communication with, one or more data storage device(s)  76 . 
     The disclosed embodiments may include exemplary methods for delivering fountain solution onto a target having a charge-retentive surface bearing an electrostatic charged pattern of charged regions thereon, with the target part of the digital image forming device  10  from which an inked image may be printed.  FIG. 6  illustrates a flowchart of such an exemplary method. As shown in  FIG. 6 , operation of the method commences at Step S 200  and proceeds to Step S 210 . 
     At Step S 210  charging a textured compliant surface layer of a fountain solution transfer member is charged by a charging device, with the transfer member including the textured compliant surface layer wrapped around a conductive layer. The conductive layer may have an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, with the undercharge regions including discharged and uncharged regions of the charge-retentive surface. 
     Operation of the method may proceed to Step S 220 , where fountain solution is supplied to the textured compliant surface layer. The textured compliant surface layer includes lands at a top surface thereof and dimples therein having a volume configured to receive and carry the fountain solution. The textured compliant surface layer has a first depth from the lands to the conductive layer. Operation of the method may proceed to Step S 230 . 
     At Step S 230 , fountain solution in the dimples may be metered to a quantity less than the total volume of the dimples, with the metering leaving gaps in the dimples between the fountain solution and the top surface. A metering member may remove excess fountain solution from the textured surface layer and dimples with a metering member in contact with the surface layer lands to form a nip therebetween. The metering member may compress the textured compliant surface layer to a second depth less than the first depth with the metering member at the nip and separating from the compressed textured compliant surface layer downstream the nip to allow surface layer expansion back to the first depth. In examples, the metering member may be more compliant than the textured compliant surface layer to dip into the dimples and remove excess fountain solution therefrom. 
     Operation of the method may proceed to Step S 240 , where the lands of the textured compliant surface are rotated adjacent the charge retentive surface to place the underfilled dimples next to or in contact with the electrostatic charged pattern of charged regions on the charge-retentive surface. Operation may proceed to Step S 250 , where the charged regions in the non-uniform electric field electrophoretically pull the fountain solution in the dimples across the gaps to wet the charge retentive surface at the electrostatic charged pattern and form a patterned fountain solution latent image on the charge-retentive surface based on the electrostatic charged pattern. Operation may cease at Step S 260 , or may continue by repeating back to Step S 210 , for delivering additional fountain solution onto the target. 
     The exemplary depicted sequence of executable method steps represents one example of a corresponding sequence of acts for implementing the functions described in the steps. The exemplary depicted steps may be executed in any reasonable order to carry into effect the objectives of the disclosed embodiments. For example, the charging step may occur before, during or after the fountain solution supplying and metering steps. No particular order to the disclosed steps of the method is necessarily implied by the depiction in  FIG. 6  or  FIG. 7  below, and the accompanying description, except where any particular method step is reasonably considered to be a necessary precondition to execution of any other method step. Individual method steps may be carried out in sequence or in parallel in simultaneous or near simultaneous timing. Additionally, not all of the depicted and described method steps need to be included in any particular scheme according to disclosure. 
     Further to the paragraph above,  FIG. 7  illustrates a flowchart of another exemplary method illustrating how the charging step may occur after the fountain solution supplying and metering steps. As shown in  FIG. 7 , operation of the method commences at Step S 300  and proceeds to Step S 310 . 
     At Step S 310 , fountain solution is supplied to the textured compliant surface layer of a fountain solution transfer member wrapped around a conductive layer. The textured compliant surface layer has a first depth from its lands to its conductive layer. Operation of the method may proceed to Step S 320 , where fountain solution in the dimples may be metered to a quantity less than the total volume of the dimples, with the metering leaving gaps in the dimples between the fountain solution and the top surface. A metering member may remove excess fountain solution from the textured surface layer and dimples with a metering member in contact with the surface layer lands to form a nip therebetween as discussed for example in greater detail above. 
     Operation of the method may proceed to Step S 330 , where a charging device charges the fountain solution in the dimples and possibly the textured compliant surface layer, depending on control variables such as the intensity and interval of the charging. The conductive layer may have an electric potential between electric potentials of the charged regions of the electrostatic charged pattern and undercharged regions of the charge-retentive surface other than the charged regions, with the undercharge regions including discharged and uncharged regions of the charge-retentive surface. 
     Operation of the method may proceed to Step S 340 , where the lands of the textured compliant surface are rotated adjacent the charge retentive surface to place the underfilled dimples next to or in contact with the electrostatic charged pattern of charged regions on the charge-retentive surface. Operation may proceed to Step S 350 , where the charged regions in the non-uniform electric field electrophoretically pull the charged fountain solution in the dimples across the gaps to wet the charge retentive surface at the electrostatic charged pattern and form a patterned fountain solution latent image on the charge-retentive surface based on the electrostatic charged pattern. Operation may cease at Step S 360 , or may continue by repeating back to Step S 310 , for delivering additional fountain solution onto the target. 
     Those skilled in the art will appreciate that other embodiments of the disclosed subject matter may be practiced with many types of image forming elements common to offset inking system in many different configurations. For example, although digital lithographic systems and methods are shown in the discussed embodiments, the examples may apply to analog image forming systems and methods, including analog offset inking systems and methods. It should be understood that these are non-limiting examples of the variations that may be undertaken according to the disclosed schemes. In other words, no particular limiting configuration is to be implied from the above description and the accompanying drawings. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, which are also intended to be encompassed by the following claims.