Patent Publication Number: US-11392062-B2

Title: Image formation with image-receiving holder and image formation medium

Description:
BACKGROUND 
     Modern printing techniques involve a wide variety of media, whether rigid or flexible, and for a wide range of purposes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a diagram including a side view schematically representing an example image formation device and/or example method. 
         FIG. 1B  is a side view schematically representing a portion of an example image formation medium assembly. 
         FIG. 2A  is a side view schematically representing an example developer unit of an example image formation device. 
         FIG. 2B  is an enlarged side view schematically representing a portion of an example developer unit and example transfer member of an example image formation device. 
         FIG. 3  is a side view schematically representing an example fluid ejection device of an example image formation device. 
         FIG. 4  is a side view schematically representing an example liquid removal device of an example image formation device. 
         FIG. 5  is a side view schematically representing an example energy transfer mechanism of an example image formation device. 
         FIG. 6  is a diagram including a side view schematically representing an example image formation device including a transfer drum and/or example method. 
         FIG. 7  is a diagram including a partial side view schematically representing removable insertion of a developer unit and of a fluid ejection device into respective receiving portions of an example image formation device. 
         FIG. 8  is a diagram including a side view schematically representing an example image formation device including an endless transfer belt and/or example method. 
         FIG. 9  is a diagram including a side view schematically representing multiple stations for multi-color printing in an example image formation device. 
         FIGS. 10A and 10B  are a block diagram schematically representing an example control portion and an example user interface, respectively. 
         FIG. 11  is a flow diagram schematically representing an example method of image formation. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise. 
     At least some examples of the present disclosure are directed to application of an electrically charged, semi-liquid image-receiving holder onto a transfer member in order to receive a pattern of ejected color ink particles to form an image and to transfer both the formed ink image and the image-receiving holder onto an image formation medium (i.e. print medium). Via at least some examples of this arrangement, significantly higher quality image formation may be achieved while significantly reducing the cost, space, time to perform the image formation. 
     In some examples, an image formation device comprises a transfer member, a first portion, a second portion, a third portion. The transfer member is to be moved along a travel path in which the first portion along the travel path is to receive a coating layer of electrically charged, semi-liquid image-receiving material (i.e. an image-receiving holder) onto the transfer member. The second portion along the travel path is to receive a pattern of droplets of ink particles within a dielectric carrier fluid onto the image-receiving holder (on the transfer member) to form at least a portion of an image on the image-receiving holder. The third portion is downstream along the travel path from the second portion and includes a charge source to emit airborne charges to charge the ink particles to move, via electrostatic attraction relative to the transfer member and relative to the electrically charged, image-receiving holder. The charged ink particles move through the carrier fluid toward the transfer member to become electrostatically fixed on the image-receiving holder. 
     In some examples, the image formation device may sometimes be referred to as a printer or printing device, image formation press, web press, or digital press. 
     In some examples, the first portion of the image formation device comprises a first receiving portion to receive a developer unit, which is to deliver the electrostatically charged, semi-liquid image-receiving holder onto the transfer member. In some examples, the image-receiving holder may sometimes be referred to as an image receiver or an image holder. In some examples, the image-receiving holder may sometimes be referred to as an initial image formation medium (i.e. initial print medium) because the image is formed on, and remains on, the image-receiving holder. Meanwhile, the “medium” to which the ink particles and the image-receiving holder are transferred together (via a transfer station) may sometimes be referred to as a second image formation medium (i.e. second print medium) or a final image formation medium (i.e. final print medium). In some examples, the initial image formation medium and the final image formation medium may sometimes be referred to as a first image formation medium and a second image formation medium, respectively. In some such examples, the second or final image formation medium is part of an image formation medium assembly in which the image made of a pattern(s) of ink particles is sandwiched between the initial (or first) image formation medium (e.g. image-receiving holder) and the final (or second) image formation medium. In some such examples, the image formed of a pattern(s) of ink particles becomes at least partially sandwiched between the first and second image formation mediums with some portions of the respective first and second image formation mediums being in direct contact with each other. 
     In some examples, the second image formation medium may sometimes be referred to as a cover layer or outer layer relative to the ink particles and relative to the first image formation medium (i.e. image-receiving holder). 
     In some examples, the image-receiving holder may sometimes be referred to as an image-receiving medium. In some examples, the semi-liquid image-receiving holder may sometimes be referred to as a paste, a semi-liquid base, semi-solid base, or base layer. 
     In some examples, the image-receiving holder is colorless and/or transparent. Moreover, in at least some examples, the image-receiving holder is not applied in a particular pattern which would form an image. Accordingly, via at least some such examples, the image-receiving holder may sometimes also be referred to as a background or base for an image, much like a blank canvas or slate upon which an image may be formed. 
     In some examples, the second portion of the image formation device comprises a second receiving portion to receive a fluid ejection device, which is to deliver a pattern or patterns of droplets of Ink particles within a dielectric carrier fluid onto the electrically charged, image-receiving holder (as carried on the transfer member) to form at least a portion of an image on the electrically charged, image-receiving holder. 
     In some examples, both the developer unit and the fluid ejection device are removably received by their respective receiving portions while in some examples, just one of the developer unit and the fluid ejection device are removably received by a respective receiving portion. 
     In some examples, the fluid ejection device may comprise a drop-on-demand fluid ejection device to eject the pattern(s) of droplets of ink particles (within the carrier fluid) onto the electrically charged, image-receiving holder as carried on the transfer member. In some examples, the fluid ejection device comprises an inkjet printhead. In some examples, the inkjet printhead comprises a piezoelectric inkjet printhead. In some examples, the inkjet may comprise a thermal inkjet printhead. In some examples, the droplets may sometimes be referred to as being jetted onto the electrically charged, image-receiving holder. 
     In some examples, the fluid ejection device is to deposit the dielectric carrier fluid as a non-aqueous fluid on the image-receiving holder. In some examples, the non-aqueous fluid comprises an isoparrafinic fluid or other oil-based liquid suitable for use as a dielectric carrier fluid, as further described below. In some examples, the dielectric carrier fluid of the ejected droplets may be free of (i.e. omit) binder materials and therefore may sometimes be referred to as being binder-free, or substantially binder-free. In some examples, the dielectric carrier fluid of the ejected droplets may be free of (i.e. omit) charge directors and therefore the droplets may sometimes be referred to as being charge-director-free or substantially charge-director-free. 
     These examples, and additional examples, will be further described below in association with at least  FIGS. 1A-11 . 
       FIG. 1A  is a diagram including a side view schematically representing an example image formation device  20 . It will be further understood that  FIG. 1A  also may be viewed as schematically representing at least some aspects of an example method of image formation. 
     As shown in  FIG. 1A , in some examples the image formation device  20  comprises a transfer member  22 , a first portion  40 , second portion  50 , third portion  60 , fourth portion  80 , and fifth portion  100 , each of which will be described below in further detail. Operation of the image formation device  20  results in an image formation medium assembly  120  (e.g. print medium assembly) as shown in  FIG. 1B  and which comprises an image-receiving holder  24  covering and bonding an image formed via ink particles  34  on an image formation medium  106  (i.e. print medium). As apparent from  FIG. 1B , in at least some examples of image formation medium assembly  120 , at least some portions of the image-receiving holder  24  may be in contact with the image formation image formation medium  106 . 
     As shown in  FIG. 1A , the transfer member  22  moves along a travel path T. In some examples, the transfer member  22  comprises an electrically conductive member, among other layers. In some examples, the transfer member may be referred to as a blanket. In some examples, the electrically conductive portion of the transfer member  22  may be in contact with an electrically conductive ground element such as a brush, roller or plate in rolling or slidable contact, respectively, with a portion of the transfer member  22 . In some examples, the ground element is in contact with an edge or end of the transfer member  22 . At least one example implementation of the transfer member  22 , and an associated ground element, is described later in association with at least  FIG. 2B . 
     In some examples, transfer member  22  may implemented on, or as part of, an endless belt or web (e.g.  611  in  FIG. 8 ) while in some examples transfer member  22  may be implemented on, or as part of, a rotating drum (e.g.  505  in  FIGS. 6-7 ). When implemented as an endless belt or web, it will be understood that the transfer member  22  may be moved along travel path T via support from an array of rollers (e.g.  610  in  FIG. 8 ), tensioners, and related mechanisms to maintain tension and provide direction to transfer member  22  along travel path T. 
     As further shown in  FIG. 1A , in some examples the first portion  40  of image formation device  20  is to receive a coating of electrically charged, semi-liquid material on the transfer member  22  to form an image-receiving holder  24 . During such coating, the electrically charged, image-receiving holder  24  becomes releasably, electrostatically fixed as a layer relative to the transfer member  22 . In this arrangement, a first surface  25 A (i.e. side) of the image-receiving holder  24  faces the transfer member  22  while an opposite second surface  25 B of the image-receiving holder  24  faces away from transfer member  22 . 
     In some examples, the first portion  40  of image formation device  20  comprises a developer unit to produce and apply the above-described coating of electrically charged, semi-liquid image-receiving holder  24  onto transfer member  22 .  FIG. 2A  provides a diagram  200  schematically representing one example developer unit  202 . In some examples, the developer unit  202  may comprise at least some of substantially the same features and attributes as a developer unit as would be implemented in a liquid electrophotographic (LEP) printer, such as but not limited to, an Indigo brand liquid electrophotographic printer sold by HP, Inc. In some examples, the developer unit  202  may comprise at least some of the features of a binary developer (BID) unit as described in Nelson et al. US20180231922. 
     As shown in  FIG. 2A , in some examples, the developer unit  202  comprises a container  204  for holding various materials  205  (e.g. liquids and/or solids) which are developed into the layer  24  forming the image-receiving holder. In some examples, the materials  205  may comprise binding materials, such as resins, binding polymers (dissolved or as particles), as well as materials such as (but not limited to) dispersants, charge directors, mineral oils, foam depressing agents, UV absorbers, cross linking initiators and components, heavy oils, blanket release promoters, and/or scratch resistance additives. In one aspect, the materials  205  in any given formulation of the image-receiving holder  24  are combined in a manner such that materials  205  will be flowable in order to enable formation of image-receiving holder  24  as a layer on transfer member  22 . In some examples, a mineral oil portion of the materials  205  is more than 50% by weight of all the materials  205 . In some such examples, the mineral oil portion may comprise an isoparrafinic fluid, which may be sold under the trade name ISOPAR. 
     In some examples, the container  204  of developer unit  202  may comprise individual reservoirs, valves, inlets, outlets, etc. for separating holding at least some of the materials  205  and then mixing them into a desired paste material to form image-receiving holder  24  as a layer on transfer member  22 . In some examples, the developed paste which forms image-receiving holder  24  may comprise at least about 20 percent to about 30 percent solids, which may comprise resin and/or other binder components and may comprise at least charge director additives along with the binder materials. In some such examples, the solids and charge director additives are provided within a dielectric carrier fluid, such as but not limited to, a non-aqueous fluid. In some examples, the non-aqueous liquid may comprise an isoparrafinic fluid, which may be sold under the trade name ISOPAR. As noted above, in some such examples the carrier fluid comprises more than 50% by weight of all of the materials  205  from which the paste is developed. In some examples, solid particles within the paste have a largest dimension (e.g. length, diameter) on the order of about 1 or about 2 microns. 
     In some examples, the charge director additives in the materials  205  may comprise a negative charge director (CD) or a synthetic charge director (SCD). In one example, the charge director can be an NCD comprising a mixture of charging components. In another example, the NCD can comprise at least one of the following: zwitterionic material, such as soya lecithin; basic barium petronate (BBP); calcium petronate; isopropyl amine dodecylebezene sulfonic acid; etc. In one specific non-limiting example, the NCD can comprise soya lecithin at 6.6% w/w, BBP at 9.8% w/w, isopropyl amine dodecylebezene sulfonic acid at 3.6% w/w and about 80% w/w isoparaffin (Isopar®-L from Exxon). Additionally, the NCD can comprise any ionic surfactant and/or electron carrier dissolved material. In one example, the charge director can be a synthetic charge director. The charge director can also include aluminum tri-stearate, barium stearate, chromium stearate, magnesium octoate, iron naphthenate, zinc napththenate, and mixtures thereof. 
     As further shown in  FIG. 2A , the developer unit  202  comprises a roller assembly  207  disposed at least partially within container  204  and selectively exposed to the paste of materials  205  being developed. The roller assembly  207  comprises a developer drum  208 , which is driven to a negative voltage (e.g. −500 V) for electrostatically charging the paste of materials  205  and electrostatically delivering the charged paste of materials  205  as layer  24  on the transfer member  22 , as shown in  FIG. 2B . In one such example, the paste of materials  205  is negatively charged. In some examples, the charge director additives receive and hold the negative charge in a manner to thereby negatively charge at least the binder materials within the paste of materials  205  when an electrical field is applied to the paste of materials  205 , such as via the development roller  208  at −500 Volts. Via such example arrangements, the image-receiving holder  24  may sometimes be referred to as an electrically charged, image-receiving holder. 
     In some examples, the developer drum or roller  208  may comprise a conductive polymer, such as but not limited to polyurethane or may comprise a metal material, such as but not limited to, Aluminum or stainless steel. 
     In some examples, the materials  205  may start out within the container  204  (among various reservoirs, supplies) with about 3 percent solids among various liquids, and via a combination of electrodes (e.g. at least  209 A,  209 B in  FIG. 2A ) “squeeze” the formulation into a paste of at least about 20 percent solids, as noted above. As shown in at least  FIG. 2B , the paste of materials  205  is applied as a layer (onto transfer member  22 ) having a thickness of about 4 to about 8 microns, in at least some examples. It will be understood that the volume and/or thickness of the layer (forming image-receiving holder  24 ) that is transferred from the developer unit  202  to the transfer member  22  may be controlled based on a voltage (e.g. −500V) of the developer roller  208  and/or a charge level of the solid particles within the paste produced by the developer unit  202 . 
     Accordingly, via such example arrangements, upon rotation of at least drum  208  of the roller assembly  207 , and other manipulations associated with container  205 , the drum  208  electrostatically attracts some of the charged developed material  205  to form the layer forming image-receiving holder  24 , which is then deposited onto transfer member  22  as shown in  FIG. 2A . 
     In some examples the transfer member  22  may comprise a transfer member  280 . In some such examples, the transfer member  280  comprises an outer layer  286 , an electrically conductive layer  284 , and a backing layer  282 . The transfer member  280  comprises at least some electrically conductive material (e.g. layer  284 ) which may facilitate attracting the negatively charged paste of materials  205  to complete formation of the image-receiving holder  24  as a layer on a surface  287 A of an outer layer  286  of the transfer member  280 , as shown in  FIG. 2B . 
     In some such examples, the outer layer  286  of transfer member  280  may comprise a layer which is compliant at least with respect to a particular media onto which the formed image will be transferred. In some examples, the outer layer  286  may comprise a silicone rubber layer and is made of a flexible, resilient material. In some such examples, the electrical conductivity of outer layer  286  may be in the range of about 10 4  Ohm-cm to about 10 7  Ohm-cm, although in some examples, the electrical conductivity may extend outside this range. The electrical properties of layer  286  can be optimized with regards to voltage drop, charge conductivity across the layer, response time, and arcing risks. 
     In some examples, the electrically conductive layer  284  of transfer member  280  may comprise of a conductive rubber like silicone, a conductive plastic like polyvinyl chloride (PVC), or a polycarbonate which typically is doped with carbon pigments to become conductive. In some examples, the electrically conductive layer  284  may comprise other conductive inks, adhesives, or curable conductive paste could also be used as well as metalized layer. In some examples, the electrically conductive layer  284  may comprise a sheet resistance of less than 100 ohm/sq and be made from materials which are more conductive than 0.1 Ohm-cm. 
     As shown in  FIG. 2B , in some examples the electrically conductive layer  284  is electrically connected to an electrical ground  270 . 
     In some examples, the transfer member  280  also comprises a backing layer  282 , which in some examples may comprise a fabric, polyamide material, and the like in order to provide some stiffness to the transfer member  280 , among other functions. In some examples, the compliant layer  286  may comprise a thickness of about 100 microns while the electrically conductive layer  284  may comprise a thickness on the order of a few microns. 
     In some examples, the transfer member  280  may comprise a release layer of a few microns thickness on top of the outer layer  286  in order to facilitate release of the image-receiving holder  24  (with an image formed via ink particles thereon) from the transfer member  280  at a later point in time, such as at a transfer station (e.g.  102  in  FIG. 1A ). 
     In some examples, the developer unit  202  may comprise a permanent component of image formation device  20 , with the developer unit  202  being sold, shipped, and/or supplied, etc. as part of image formation device  20 . It will be understood that such “permanent” components may be removed for repair, upgrade, etc. as appropriate. 
     As further described later in association with at least  FIGS. 6-7 , in some examples the first portion  40  of image formation device  20  may comprise a first receiving portion  510  to removably receive a developer unit (e.g.  202  in  FIG. 2A ), such as in some examples in which the developer unit  202  is removably insertable into a first receiving portion  510 , as shown in at least  FIGS. 6-7 . The first receiving portion  510  is sized, shaped, and positioned relative to transfer member (e.g.  505  in  FIGS. 6-7 ), as well as relative to other components of image formation device  20 , such that upon removable insertion into to first receiving portion  510  (as represented by arrow V in  FIG. 7 ), the developer unit  202  is positioned to deliver the image-receiving holder  24  onto transfer member  505 , in a manner similar to that shown in  FIGS. 1A, 2A . In some such examples, the developer unit  202  may comprise a consumable which is periodically replaceable due to wear, exhaustion of a supply of ink-binder material, developer components, etc. In some such examples, the developer unit  202  may be sold, supplied, shipped, etc. separately from the rest of image formation device  20  (or  500  in  FIG. 6, 600  in  FIG. 8 ) and then installed into the respective image formation device (e.g.  20 ,  500 ,  600 ) upon preparation for use of the image formation device at a particular location. The first receiving portion  510  in  FIGS. 6-7  may sometimes be referred to as a first receptor. Accordingly, it will be apparent that in some examples the first receiving portion  510  may comprise part of the first portion  40  of image formation device  20  in  FIG. 1A  or part of first portion  40  in image formation device  600  in  FIG. 8 . 
     In some examples the first portion  40  of the example image formation device  20  involves developing the image-receiving holder  24  without any color pigments in the image-receiving holder  24 , such that the image-receiving holder  24  may sometimes be referred to as being colorless. In this arrangement, in some examples the image-receiving holder  24  corresponds to a liquid-based ink formulation which comprises at least substantially the same components as used in liquid electrophotographic (LEP) process, except for omitting the color pigments. In addition to being colorless in some examples, the ink-binder material also may be transparent and/or translucent upon application to an image formation medium or to a transfer member  22 . 
     In some examples, the image-receiving holder  24  may comprise some color pigments so as to provide a tint. In some such examples, such color pigments may be transparent or translucent as well so as to not interfere with, or otherwise, affect the formation or appearance of an image via the ink particles  34  deposited in second portion  50 , such as via a fluid ejection device (e.g.  321  in  FIG. 3 ). 
     In at least some examples in which the image-receiving holder  24  omits color pigments, the materials of the image-receiving holder  24  effectively do not comprise part of the image resulting from the deposited color ink particles which will be later transferred (with the image-receiving holder  24 ) onto an image formation medium. Accordingly, in some such examples the image-receiving holder  24  also may sometimes be referred to as a non-imaging, image-receiving holder  24 . 
     In some such examples, the image-receiving holder  24  comprises all (e.g. 100 percent) of the binder used to hold an image (formed of and including ink particles  34 ) on transfer member  22  and later on an image formation print medium. In some such examples, image-receiving holder  24  comprises at least substantially all (e.g. substantially the entire volume) of the binder used to hold the image (including ink particles). In some such examples, in this context the term “at least substantially all” (or at least substantially the entire) comprises at least 95%. In some such examples “at least substantially all” (or at least substantially the entire) comprises at least 98%. In some examples in which the image-receiving holder  24  may comprise less than 100 percent of the binder used to hold the image on the transfer member  22  (and later on an image formation medium), with the remaining desired amount of binder being provided from droplets  52  delivered in the first portion  40  of image formation device  20 . It will be understood that the term binder may encompass resin, binder materials, and/or polymers, and the like to complete image formation with the ink particles  34 . 
     As further noted below, formulating the image-receiving holder  24  to comprise at least substantially all of the binder material(s) to be used to hold the image relative to the transfer member  22  (and later on an image formation medium) acts to free the second portion  50  (and fluid ejection device  321 ) so that, in at least some examples, the droplets (e.g.  52  in  FIG. 1, 322  in  FIG. 3 ) may omit any binder material, and therefore be “binder-free.” Accordingly, in some examples, the droplets  52  may sometimes be referred to as being binder-free droplets. 
     In some examples, the droplets  52  omit charge director additives and therefore may sometimes be referred to as being charge-director-free. In some such examples, the image-receiving holder  24  may comprise some charge-director additives as further described with respect to developer unit  202  ( FIG. 2A-2B ). 
     This example arrangement of supplying all or substantially all of the binder (for forming the image) via the image-receiving holder  24  may help to operate a fluid ejection device (e.g.  321  in  FIG. 3, 6-7 ) with fewer maintenance issues because the absence (or nearly complete absence) of a binder in the droplets  52  may avoid fouling the ejection elements, which may sometimes occur with droplets  52  including binder material for forming an image on an image formation medium. In addition to simplifying maintenance, this arrangement may increase a longevity of the ejection elements (e.g. printhead) of the fluid ejection device  321 . 
     In some examples, the developer unit  202  is to apply the image-receiving holder  24  in a volume to cover at least substantially the entire surface of the transfer member  22  in at least the area in which the image is be formed on transfer member  22  and immediately surrounding regions. In some examples, in this context, the term “substantially the entire” comprises at least 95 percent, while in some examples, the term “substantially the entire” comprises at least 99 percent. 
     In some examples, the image-receiving holder  24  is applied to form a uniform layer covering an entire surface of the transfer member  22  (at least including the area in which an image is to be formed). This arrangement stands in sharp contrast to some liquid electrophotographic printers in which liquid ink (with color pigments) is applied just to areas of a charged photo imaging plate (PIP), which have been discharged in a pattern according to the image to be formed. According, the application of a uniform layer (covering an entire surface of the transfer member  22 ) of the image-receiving holder in the example image formation device  20  bears no particular relationship to the pattern of an image to be formed on the image-receiving holder  24 . Therefore, in some instances, the image-receiving holder  24  may sometimes be referred to as a non-imaging, image-receiving holder  24 . 
     Moreover, in another aspect, coating image-receiving holder  24  on transfer member  22  may effectively eliminate “image memory” which otherwise may sometimes occur when forming ink images directly on a transfer member  22 . In addition, the coating of image-receiving holder  24  on the transfer member  22  may protect the transfer member  22  from dust from a print medium (e.g. paper dust) and/or from plasma associated with production of charges  64  via the charge source  62 , as further described later. Among other aspects, this arrangement may increase a longevity of the transfer member  22 . In some examples, the employment of the image-receiving holder  24  to receive and transfer an image (made of ink particles  34 ) may substantially increase the longevity of the transfer member  22 . In some examples, in this context the term “substantially increase” may correspond to an increase in longevity of at least 25%, at least 50%, or at least 75%. In some examples, in this context the term “substantially increase” may correspond to an increase in longevity of at least 2×, at least 3×, or at least 5×. 
     It will be understood that the developer unit  202  (which may be permanent or may be removably insertable into first receiving portion  510 ) may be implemented in an image formation device whether the transfer member  22  is in the form drum as shown in  FIGS. 6-7  or in the form of a belt as shown in  FIG. 8 . 
     As shown in  FIG. 1A , in some examples the second portion  50  of image formation device  20  is located downstream from the first portion  40  along the travel path T, and is to receive droplets  52  of ink particles  34  within a dielectric carrier fluid  32  on the image-receiving holder  24  (as carried by transfer member  22 ). The depiction within the dashed lines A in  FIG. 1A  represents ink particles  34  and carrier fluid  32  after being received on the image-receiving holder  24  (on transfer member  22 ) to form at least a portion of an image on the image-receiving holder  24 . In some examples, the droplets  52  from which ink particles  34  are formed may comprise pigments, dispersants, the carrier fluid  32 , etc. In some examples, the droplets  52  may comprise at least some binder materials. However, in at least some examples, the droplets  52  omit binder materials (e.g. resin, binding polymers, etc.), which are instead supplied via the image-receiving holder  24 . Further details regarding droplets  52  are described below in association with at least  FIG. 3 . 
     As previously noted, in some examples the second portion  50  of the image formation device  20  may comprise a fluid ejection device.  FIG. 3  is a diagram  320  including a side view schematically representing an example fluid ejection device  321  which may be implemented as part of the second portion  50 , in some examples. As shown in  FIG. 3 , fluid ejection device  321  is positionable at a location spaced apart and above the transfer member  22  (and image-receiving holder  24  thereon). In some examples, the fluid ejection device  321  comprises a drop-on-demand fluid ejection device. In some examples, the drop-on-demand fluid ejection device comprises an inkjet printhead. In some examples, the inkjet printhead comprises a piezoelectric inkjet printhead while in some examples, the inkjet printhead comprises a thermal inkjet printhead. In some examples, the fluid ejection device  321  may comprise other types of inkjet printheads. 
     In some examples, as further described later in association with at least  FIG. 10A , among directing other and/or additional operations, a control portion  800  is instruct, or to cause, the fluid ejection device  321  to deliver the droplets  322  (e.g.  52  in  FIG. 1A ) of ink particles  34  within the dielectric carrier fluid  32  onto the image-receiving holder  24  on transfer member  22 , such as within the second portion  50  along the travel path T of image-receiving holder  24  (on the transfer member  22 ). 
     In some examples, the fluid ejection device  321  may comprise a permanent component of image formation device  20 , with the fluid ejection device  321  being sold, shipped, and/or supplied, etc. as part of image formation device  20 . It will be understood that such “permanent” components may be removed for repair, upgrade, etc. as appropriate. 
     As further described later in association with at least  FIG. 6 , in some examples the second portion  50  of image formation device  20  may comprise a second receiving portion  520  to removably receive a fluid ejection device (e.g.  321  in  FIG. 3 ), such as in some examples in which the fluid ejection device  321  is removably insertable into the second receiving portion  520 , as shown in at least  FIG. 7 . The second receiving portion  520  is sized, shaped, and positioned relative to transfer member (e.g.  505  in  FIGS. 6-7 ), as well as relative to other components of image formation device  20 , such that upon removable insertion relative to second receiving portion  520  (as represented by arrow V in  FIG. 7 ), the fluid ejection device  321  is positioned to deliver (e.g. eject) the droplets  322  of ink particles  34  and dielectric carrier fluid  32  on the image-receiving holder  24  carried by transfer member  22 , in a manner similar to that shown in  FIG. 1A . 
     In some such examples, the fluid ejection device  321  may comprise a consumable which is periodically replaceable due to wear, exhaustion of an ink supply, etc. In some such examples, the fluid ejection device  321  may be sold, supplied, shipped, etc. separately from the rest of image formation device  20  (or  500  in  FIG. 6, 600  in  FIG. 8 ) and then installed into the respective image formation device (e.g.  20 ,  500 ,  600 ) upon preparation for use of the image formation device at a particular location. The second receiving portion  520  may sometimes be referred to as a second receptor. In some examples, the second receiving portion  520  may comprise supports  521 . 
     It will be understood that the second receiving portion  520  may be implemented in a second portion  50  of an image formation device whether the transfer member  22  is in the form drum as shown in  FIGS. 6-7  or in the form of a belt as shown in  FIG. 8 . 
     With further reference to at least  FIGS. 1A, 3, 6-8 , in some examples, as part of ejecting droplets (e.g.  52  in  FIG. 2, 322  in  FIG. 3 , etc.), the fluid ejection device (e.g.  321  in  FIG. 3 ) is to deposit the dielectric carrier fluid  32  on the image-receiving holder  24  as a non-aqueous liquid. In some examples, the non-aqueous liquid comprises an isoparrafinic fluid, which may be sold under the trade name ISOPAR. In some such examples, the non-aqueous liquid may comprise other oil-based liquids suitable for use as a dielectric carrier fluid. 
     As further shown in  FIG. 1A , in some examples, the third portion  60  of image formation device  20  is located downstream along the travel path T from the second portion  50  and includes a charge source  62  to emit airborne charges  64  to charge the ink particles  34 , as represented via the depiction in dashed lines B in  FIG. 1A . Once charged, the ink particles  34  move, via attraction relative to the charged image-receiving holder  24  (and transfer member  22 ), through the carrier fluid  32  toward the second surface  25 B of the image-receiving holder  24  to become electrostatically fixed on the image-receiving holder  24 , as represented via the depiction in dashed lines C in  FIG. 1A . 
     With further reference to  FIG. 1A , in some examples the charge source  62  in the third portion  60  may comprise a corona, plasma element, or other charge generating element to generate a flow of charges  64 . The generated charges may be negative or positive as desired. In some examples, the charge source  62  may comprise an ion head to produce a flow of ions as the charges. It will be understood that the term “charges” and the term “ions” may be used interchangeably to the extent that the respective “charges” or “ions” embody a negative charge or positive charge (as determined by charge source  62 ) which can become attached to the ink particles  34  to cause all of the charged ink particles to have a particular polarity, which will be attracted to ground. In some such examples, all or substantially all of the charged ink particles  34  will have a negative charge or alternatively all or substantially all of the charged ink particles  34  will have a positive charge. In one example, the charges  64  are positive charges as shown in  FIG. 1A . While the charges  64  shown in the various examples in  FIGS. 1A-12  are depicted as having a particular polarity (positive or negative), it will be understood that the polarity of charges  64  may be selected and implemented in view of the polarity of other elements of an example image formation device (or associated with an example image formation device), such as a polarity of elements (e.g. charge directors, binder particles) within the electrically charged, image-receiving holder  24 . It will be understood that other elements (e.g. transfer member  22 ,  280 ) in contact with image-receiving holder  24  may exhibit, may develop, or be caused to exhibit charges having a polarity opposite from the polarity of the charges  64  (and therefore opposite from the polarity of the charged ink particles  34 ). Via such example arrangements of opposite polarity charges, the electrostatic attraction forces may be at least partially implemented. In some examples, the charges  64  may affect the charge level and/or the polarity of image-receiving holder  24  to keep the electrostatic attraction forces of particles  34  at least partially implemented. 
     Via such example arrangements, the charged ink particles  34  become electrostatically fixed on the electrically charged, image-receiving holder  24  in a location on the image-receiving holder  24  generally corresponding to the location (in an x-y orientation) at which they were initially received onto the image-receiving holder  24  in the second portion  50  of the image formation device  20 . Via such electrostatic fixation, the ink particles  34  will retain their position on electrically charged, image-receiving holder  24  even when other ink particles (e.g. different colors) are added later with additional liquid, even when excess liquid is mechanically removed, etc. It will be understood that while the ink particles  34  may retain their position on image-receiving holder  24 , some amount of expansion of a dot (formed of ink particles  34 ) may occur after the ink particles  34  (within carrier fluid  32 ) are jetted onto image-receiving holder  24  and before they are electrostatically pinned in their respective locations (which forms the pattern of the image). In some examples, the charge source  42  is spaced apart by a predetermined distance (e.g. downstream) from the location at which the droplets  52  are received (or ejected) in order to delay the electrostatic fixation (per operation of charge source  62 ), which can increase a dot size on image-receiving holder  24 , which in turn may lower ink consumption. 
     As shown in  FIG. 1A , in some examples a fourth portion  80  is located downstream along the travel path T from the third portion  60  and comprises a liquid removal element(s)  82  to at least mechanically remove excess volumes of liquid, including carrier fluid  32 ) which has accumulated on the image-receiving holder  24  as a result of receiving droplets  52  in the second portion  50 . After the electrostatic fixation of the ink particles  34  (in the form of at least a portion of an image) as shown via the dashed box C in third portion  60  in  FIG. 1A , the excess liquid is no longer useful for the current instance of image formation and therefore is removed as shown in fourth portion  80 . In some examples, the collected excess liquid may be recovered and re-used in future depositions of droplets in the second portion  50  in subsequent instances of image formation via the image formation device  20  and/or re-used for other purposes. 
     In some examples, the first liquid removal element(s)  82  is to remove the carrier fluid  32  without heating the fluid  32  at all or without heating the carrier fluid  32  above a predetermined threshold. In some instances, such liquid removal may sometimes be referred to as cold liquid removal (e.g. cold oil removal) by which the liquid is removed at relatively cool temperatures, at least as compared to high heat drying techniques. Accordingly, in some such examples, a mechanical element (e.g. squeegee roller) of the first liquid removal element(s)  82  may slightly heat the carrier fluid  32  and/or other liquid without using heat as a primary mechanism to remove the carrier fluid  32  from the ink particles  34  on image-receiving holder  24 . In some such examples, performing such cold liquid removal may substantially decrease the amount of energy used to remove deposited liquid (e.g. from the top of image-receiving holder  24 ) as compared to using a heated air dryer primarily or solely to remove the liquid. In some examples, in this context the term “substantially decrease” may correspond to at least 10×, at least 20×, or at least 30×. In addition, using cold oil removal via example image formation devices may significantly decrease the space or volume occupied by the example image formation device  20 , thereby reducing its cost and/or cost of space in which the image formation device  20  may reside. 
     As further shown in the diagram  340  of  FIG. 4 , in some examples the first liquid removal element(s)  82  may comprise a squeegee and/or roller  304  or other mechanical structure to remove the excess carrier fluid  322 A (and any other liquid) from the surface of image-receiving holder  24 . In some examples, the electrostatically fixed (e.g. pinned) charged ink particles  34  remain fixed in their respective locations (e.g. pattern) on image-receiving holder  24  during this mechanical removal of liquid at least because the electrostatic fixation forces are greater than the shear forces exhibited via the tool(s) used to mechanically remove the carrier fluid  32 . As previously noted, after such liquid removal, in some examples a minimal amount  322 B of liquid may remain with ink particles  34  on image-receiving holder  24  as shown in  FIG. 4 . 
     In the fourth portion  80 , in some examples, at least 80 percent of the jetted carrier fluid  32  on image-receiving holder  24  is removed. In some examples, at least 90 percent of the jetted carrier fluid  32  is removed. In some examples, at least 95 percent of the jetted carrier fluid  32  is removed. However, in some examples, first liquid removal element(s)  82  may remove at least 50 percent of total liquid, which includes the carrier fluid  32 , from image-receiving holder  24 . 
     In some examples the image formation device  20  may further comprise a second liquid removal portion downstream from the first liquid removal element(s)  82 . This second liquid removal portion may comprise part of the fourth portion  80  or comprise a sixth portion between the fourth portion  80  and fifth portion  100 . This second liquid removal portion acts to remove any liquid not removed via first liquid removal element(s)  82  (in fourth portion  80 ) and thereby result in dried ink particles  34  on the image-receiving holder  24 , as represented via the depictions in dashed lines E in  FIG. 1A , or as later shown in  FIG. 5 . In some examples, at least some of the liquid removed via the second liquid removal portion includes some liquid (e.g. carrier fluid) from the image-receiving holder  24  such that operation of the second liquid removal portion facilitates further solidification of the image-receiving holder  24  prior to its transfer to an image formation medium (e.g.  106  in  FIG. 1B ). 
     In some such examples, this second liquid removal portion may be implemented as shown in the diagram  360  of  FIG. 5  as an energy transfer mechanism  362  by which energy (represented via arrows W) is transferred to the liquid  32 , ink particles  34 , and image-receiving holder  24  in order to dry the ink particles  34  on the image-receiving holder  24  and/or dry the image-receiving holder  24 . 
     In some examples, the energy transfer mechanism  362  may comprise a heated air element to direct heated air (represented via W) onto at least the carrier fluid  32  and ink particles  34  on image-receiving holder  24 . In some examples, the heated air is controlled to maintain the ink particles  34 , image-receiving holder  24 , etc. at a temperature below 60 degrees C., which may prevent irregularities in the image-receiving holder  24 . 
     In some examples, the energy transfer mechanism  362  may comprise a radiation element to direct at least one of infrared (IR) radiation and ultraviolet (UV) radiation (as represented via arrows W) onto the liquid  32 , ink particles  34 , and in image-receiving holder  24  to eliminate liquid remaining after operation of the first liquid removal element(s)  82 . 
     While at least some examples of image formation device  20  may comprise an energy transfer mechanism  362  to remove remaining amounts of liquid after liquid removal element(s)  82 , it will be understood that the transmitted energy also may facilitate solidifying the binder (from image-receiving holder  24 ) with ink particles  34  (from droplets  52 ) to complete formation and solidification of the image on the image-receiving holder  24 . 
     As further shown in  FIG. 1A , in some examples image formation device  20  may further comprise a transfer station  102  (in fifth portion  100 ) downstream from the liquid removal element(s)  82  (in fourth portion  80 ). Via at least a transfer roller (e.g. drum)  104  the transfer station  102  is to transfer at least substantially the entire image-receiving holder  24  with at least substantially the entire volume of ink particles  34  thereon (in the form of an image) onto an image formation medium  106  (e.g. image formation medium). As previously noted, this complete (or nearly complete transfer) may increase image quality, protect the transfer member, etc. In addition, in this way, no residue is left remaining on the transfer member, thereby simplifying or eliminating later cleaning of the transfer member, such as between consecutive printing episodes. 
     In some examples, the transfer station  102  may employ heat, pressure, and/or electrical bias, etc. in order to effect the above-described transfer. 
     In addition, by transferring the image-receiving holder  24  with the ink particles  24  (as a pattern or form of an image), the image-receiving holder  24  becomes an outermost layer of a completed image formation medium assembly  120  shown in  FIG. 1B , thereby protecting the image formed of ink particles  34  and helping bond the formed image to the image formation medium  106 . 
     In some examples, the image-receiving holder  24  may sometimes be referred to as an image receiver or an image holder. In some examples, the image-receiving holder  24  may sometimes be referred to as an initial image formation medium (i.e. initial print medium) because the image is formed on, and remains on, the image-receiving holder. Meanwhile, the “medium” (e.g.  106  in  FIGS. 1A-1B ) to which the ink particles and the image-receiving holder are transferred together (via a transfer station) may sometimes be referred to as a second image formation medium (i.e. second print medium) or a final image formation medium (i.e. final print medium). In some examples, the initial image formation medium (e.g.  24  in  FIG. 1A ) and the final image formation medium (e.g.  106  in  FIGS. 1A-1B ) may sometimes be referred to as a first image formation medium and a second image formation medium, respectively. In some such examples, the second or final image formation medium is part of an image formation medium assembly (e.g.  120  in  FIG. 1B ) in which the image made of a pattern(s) of ink particles  34  are at least partially sandwiched between the initial (or first) image formation medium  24  (e.g. image-receiving holder) and the final (or second) image formation medium  106 . In some such examples, the image formed of a pattern(s) of ink particles  34  becomes at least partially sandwiched between the first and second image formation mediums with some portions of the respective first and second image formation mediums (e.g.  24 ,  106 ) being in direct contact with each other, as shown in  FIG. 1B  in one example. 
     In some examples, the second image formation medium may sometimes be referred to as a cover layer or outer layer relative to the ink particles and relative to the first image formation medium (i.e. image-receiving holder). 
     In some examples, the image-receiving holder may sometimes be referred to as an image-receiving medium. In some examples, the semi-liquid image-receiving holder may sometimes be referred to as a paste, a semi-liquid base, semi-solid base, or base layer. 
     In transferring all or substantially all of the ink particles  34  (from their supported position relative to transfer member  22 ) onto an image formation medium  106 , the image-receiving holder  24  facilitates additional forms of printing or image formation. In particular, because all of the ink particles  34  can be transferred, the fluid ejection device (e.g.  321 ) (via instructions from control portion  800 ) can perform stochastic-screening image formation via the ink particles  34  in which at least some of the dot sizes (made of ink particles  34 ) or all of the dot sizes used to form an image may be less than 50 microns on the image-receiving holder  24  (supported by the transfer member  22 ). In some examples, at least some of the dot sizes or all of the dot sizes may be 45 microns and/or less than 45 microns. In some examples, at least some of the dot sizes or all of the dot sizes may be 40 microns and/or less than 40 microns. In some examples, at least some of the dot sizes or all of the dot sizes may be 35 microns and/or less than 35 microns. In some examples, at least some of the dot sizes or all of the dot sizes may 30 microns and/or may be less than 30 microns. In some examples, at least some of the dot sizes or all of the dot sizes may 25 microns and/or may be less than 25 microns. In some such examples, at least some of the dot sizes or all of the dot sizes formed on the image-receiving holder  24  may be 20 microns or less than 20 microns. It will be understood that, in at least some examples, the ink particles  34  may have a largest dimension (e.g. diameter, length, etc.) less than 1 micron. 
     In some instances, the stochastic screening may sometimes be referred to as frequency modulation (FM) screening. In some examples, the stochastic screening may comprise printing according to a pseudo-random distribution of halftone dots in which frequency modulation (FM) is used to control the density of dots according to the gray level desired. Via such stochastic screening, the fluid ejection device (e.g.  321  in  FIG. 3 ) deposits a fixed size of dots (e.g. on the order of 20 microns) and implements a distribution density that varies depending on the color&#39;s tone. In contrast, in amplitude modulation (AM) halftone printing the printed dots may vary in size depending on the color tone being represented, while maintaining a geometric and fixed spacing of the dots. However, in amplitude modulation halftone printing the minimum size of the printed dots is substantially greater (e.g. 50%, 75%, 100%) greater than a size of dots printable via stochastic screening, such as available via the example image formation device  20 . 
     Via stochastic screening in some examples, the example image formation device  20  may produce higher resolution images on a print medium, a greater color gamut, among other aspects. 
     It will be understood that in some examples, the sequence of operation of some portions of image formation device  20  may be re-arranged in some instances. Moreover, it will be understood that in some examples the labeling of the various portions as first, second, third, fourth, fifth portions (e.g.  40 ,  60 ,  80 ,  100 , etc.) does not necessarily reflect an absolute ordering or position of the respective portions along the travel path T. Moreover, such labeling of different portions also does not necessarily represent the existence of structural barriers or separation elements between adjacent portions of the image formation device  20 . Furthermore, in some examples, the components of the image formation device  20  may be organized into a fewer or greater number of portions than represented in  FIG. 1A . 
       FIG. 6  is a diagram including a side view schematically representing at least a portion of an example image formation device  500 . In some examples, image formation device  500  comprises at least some of substantially the same features as image formation device  20  as previously described in association with  FIGS. 1A-5 , except with transfer member  22  arranged in the form of, or as part of, a drum  505  and with the various portions  40 ,  50 ,  60 ,  80 ,  100 , etc. arranged in a circumferential pattern about drum  505  as shown in  FIGS. 6-7 . For illustrative simplicity, the various portions  40 ,  50 ,  60 ,  80 ,  100  of image formation device  500  are represented via boxes instead of dashed lines as in  FIG. 1A  and  FIG. 9 . 
     As shown in  FIG. 6 , first portion  40  comprises the previously identified first receiving portion  510  to removably receive a developer unit, such as developer unit  202  which is removably insertable into the first receiving portion  510  as shown in  FIG. 7 . In some examples, the first receiving portion  510  may comprise supports  511 . In some examples, the developer unit  202  may comprise at least some of substantially the same features and attributes as developer unit  202  of  FIGS. 2A-2B . As in  FIGS. 1-2B , the developer unit  202  develops and electrostatically deposits an image-receiving holder  24  onto an outer surface  507  of drum  505  to receive droplets of ink, etc. 
     In some examples, as further described later in association with at least  FIG. 10A , among directing other and/or additional operations, a control portion  800  is instruct, or to cause, the developer unit  202  to deliver the image-receiving holder  24  onto transfer member  505 , such as within the first portion  40  along the travel path T of transfer member  505  in  FIG. 6 . 
     As shown in  FIG. 6 , second portion  50  is downstream from first portion  40  (given a rotational direction P of drum  505 ) and in some examples may comprises the previously identified second receiving portion  520  to removably receive a fluid ejection device, such as fluid ejection device  321  which is removably insertable into the second receiving portion  520  as shown in  FIG. 7 . In some examples, the fluid ejection device  321  may comprise at least some of substantially the same features and attributes as fluid ejection device  321  of  FIG. 3 . As in  FIG. 3 , the fluid ejection device  321  when deployed in image formation device  500  in  FIGS. 6-7  is to deposit droplets  322  (e.g.  52  in  FIG. 1A ) of ink particles  34  within a dielectric carrier fluid  32  onto an image-receiving holder  24  supported on the outer surface  507  of drum  505 . 
     In some examples, as further described later in association with at least  FIG. 10A , among directing other and/or additional operations, a control portion  800  is instruct, or to cause, the fluid ejection device  321  to deliver the droplets  322  (e.g.  52  in  FIG. 1A ) onto the image-receiving holder  24  on transfer member  505 , such as within the first portion  40  along the travel path T of transfer member  505  in  FIG. 6 . 
     As further shown in  FIG. 6 , in some examples the image formation device  500  may comprise a fifth portion  100 , which may comprise a transfer station  540 . The transfer station  540  may comprise at least some of substantially the same features and attributes as transfer station  102  of image formation device  20  in  FIG. 1A . 
     In a manner similar to that previously described for image formation device  20 , the various portions  40 ,  50 ,  60 ,  80 ,  100  of image formation device  500  in  FIGS. 6-7  may operate as previously described in association with  FIGS. 1A-5  to form an image on a print medium  546 . As further shown in  FIG. 6 , in some examples the image formation device  500  comprises a sixth portion  130 , which may comprise a dryer  530  or comprise another implementation of example energy transfer mechanism  362  in  FIG. 5 . 
       FIG. 8  is a diagram including a side view schematically representing at least a portion of an example image formation device  600 . In some examples, image formation device  600  comprises at least some of substantially the same features as image formation device  20 ,  500  as previously described in association with  FIGS. 1A-7 , except with transfer member  22  arranged in the form of, or as part of, an endless belt or web  611  and with the various portions  40 ,  50 ,  60 ,  80 ,  100 , etc. of image formation device  600  arranged in a pattern along belt  611  which travels in an endless loop, as shown in  FIGS. 6-7 . For illustrative simplicity, the various portions  40 ,  50 ,  60 ,  80 ,  100  of image formation device  600  are represented via boxes instead of dashed lines as in  FIG. 1A  and  FIG. 9 . 
     In some examples, transfer belt  611  forms part of a belt assembly  610  including various rollers  612 ,  614 ,  616 ,  618 ,  620 , etc. and related mechanisms to guide and support travel of belt  611  (e.g. transfer member  22  in  FIG. 1A ) along travel path T and through the various portions  40 ,  50 ,  60 ,  80 ,  100 , etc. of image formation device  600 . 
     In a manner similar to that previously described for image formation device  20 , the various portions  40 ,  50 ,  60 ,  80 ,  100 , etc. operate as previously described in association with  FIGS. 1A-7  to form an image on a print medium  546 . As further shown in  FIG. 8 , in some examples the image formation device  600  comprise a fifth portion  100 , which may comprise a transfer station  630  comprising at least some of substantially the same features and attributes as the previously described transfer stations (e.g.  102  in  FIG. 1A ;  540  in  FIG. 6 ). In some instances, the roller  620  may serve as, or be referred to, as an impression cylinder. As in the image formation device  500  of  FIG. 6 , the sixth portion  130  in the image formation device  600  of  FIG. 8  also may comprise a dryer  530  or another implementation of example energy transfer mechanism  362  in  FIG. 5 . 
     As previously described in association with at least  FIGS. 1A-7 , in some examples the first portion  40  may comprise a first receiving portion  510  ( FIGS. 6-7 ) to removably receive a developer unit  202  and/or the second portion  50  may comprise a second receiving portion  520  ( FIGS. 6-7 ) to removably receive a fluid ejection device  321 . 
       FIG. 9  is a diagram including a side view schematically representing at least a portion of an example image formation device  700 . In some examples, the image formation device  700  comprises a transfer member  722  and a series of stations  710 ,  720 , etc. arranged along the travel path T of the transfer member  22  in which each station is to provide one color ink of a plurality of different color inks onto the media. It will be further understood that  FIG. 9  also may be viewed as schematically representing at least some aspects of an example method of image formation. 
     In some examples, the image formation device  700  comprises at least some of substantially the same features and attributes as the image formation devices  20 ,  500 ,  600 , as previously described in association with  FIGS. 1A-8 . However, in image formation device  700  a series of image formation stations  710 ,  720  etc. is provided along a travel path of the transfer member  22 . It will be understood that the image formation device  700  can be implemented with the transfer member  22  as a belt ( FIG. 8 ) or as a drum ( FIGS. 6-7 ) and the various first, second portions, etc. appropriately arranged to such configuration. 
     In a manner at least substantially the same as in the examples in  FIGS. 1A-8 , a first portion  40  is located upstream from the series of stations  710 ,  720  in order to provide an image-receiving holder  24  on a transfer member  22 . Following the first portion  40 , each subsequent, different image formation station  710 ,  720 , etc. provides for at least partial formation of an image on the image-receiving holder  24  (carried by transfer member  22 ) by a respectively different color ink. Stated differently, the different stations apply different color inks such that a composite of the differently colored applied inks forms a complete image on the image-receiving holder  24  as desired. In some examples, the different color inks correspond to the different colors of a color separation scheme, such as Cyan (C), Magenta (M), Yellow (Y), and black (K) wherein each different color is applied separately as a layer to the image-receiving holder  24  as image-receiving holder  24  (as supported by transfer member  22 ) moves along travel path T. 
     As shown in  FIG. 9 , each station  710 ,  720 , etc. may comprise at least a second portion  50  and a third portion  60  having substantially the same features as previously described. In some examples, each station may comprise additional portions, such as but not limited to, portion  80  as described in association with at least  FIGS. 1A-8 . 
     As further shown in  FIG. 9 , the image formation device  700  may comprise additional stations, and as such, the black circles III, IV represent further stations like stations  710 ,  720  for applying additional different color inks onto an image-receiving holder  24  (as carried by transfer member  22 ). In some examples, the additional stations may comprise a fewer number or a greater number of additional stations (e.g. III, IV) than shown in  FIG. 9 . 
     In some examples, each station  710 ,  720 , etc. of image formation device  700  can include its own liquid removal element (e.g.  82  in  FIG. 1A ). 
     However, in some examples, image formation device  700  comprises just one fourth portion  80  (including at least one liquid removal element(s)  82 ) which is located downstream from multiple color stations  710 ,  720 , etc. such that the cumulative excess liquid (from printing at those stations) is removed all at once. Stated differently, each of the respective color stations  710 ,  720  omit a liquid removal element (e.g.  82 ) and liquid removal does not take place until after the last color station in the series of color stations  710 ,  720 , etc. 
     In some examples, the image formation device  700  may comprise at least one dryer or other implementation of an energy transfer mechanism (e.g.  362  in  FIG. 5, 530  in  FIG. 6 ) downstream from the multiple color stations  710 ,  720 , with the at least one dryer being downstream along the travel path T from the last liquid removal element(s)  82  at the end of the multiple color stations  710 ,  720 , etc. 
     In some examples, the image formation device  700  also may comprise a fifth portion  100  downstream from the multiple stations  710 ,  720 , etc. and which comprises a transfer station comprising at least some of substantially the same features and attributes as transfer station  102  in  FIG. 1A, 540  in  FIG. 6, 630  in  FIG. 8 , etc. 
     Accordingly, upon the completion of each respective station (e.g.  710 ,  720 ), a layer of ink particles  34  will be fixed to the substrate  24 , such that later stations will add additional layers of ink particles  34  (of different colors) onto the previous layer(s) of fixed ink particles  34 . It will be understood that, for illustrative simplicity, station  720  in  FIG. 9  omits depiction of a previously deposited, fixed layer of ink particles from station  710 . 
       FIG. 10A  is a block diagram schematically representing an example control portion  800 . In some examples, control portion  800  provides one example implementation of a control portion forming a part of, implementing, and/or generally managing the example image formation devices  20 ,  500 ,  600 ,  700  as well as the particular stations, portions, elements, devices, user interface, instructions, engines, and/or methods, as described throughout examples of the present disclosure in association with  FIGS. 1A-9 and 11 . 
     In some examples, control portion  800  includes a controller  802  and a memory  810 . In general terms, controller  802  of control portion  800  comprises at least one processor  804  and associated memories. The controller  802  is electrically couplable to, and in communication with, memory  810  to generate control signals to direct operation of at least some the image formation devices, various portions, stations, devices, and/or elements of the image formation devices, such as but not limited to, developer units, fluid ejection devices, charge sources, liquid removal portions, liquid removal, dryers, transfer stations, user interfaces, instructions, engines, functions, and/or methods, as described throughout examples of the present disclosure. In some examples, these generated control signals include, but are not limited to, employing instructions  811  stored in memory  810  to at least direct and manage developing and/or applying an image-receiving holder onto a transfer member, depositing droplets of ink particles and carrier fluid to form an image on a media, directing charges onto ink particles, removing liquids, transferring ink and image-receiving holder onto a print medium, performing stochastic-type screening (i.e. frequency modulation image formation), etc. as described throughout the examples of the present disclosure in association with  FIGS. 1A-9 and 11 . In some instances, the controller  802  or control portion  800  may sometimes be referred to as being programmed to perform the above-identified actions, functions, etc. In some examples, at least some of the stored instructions  811  are implemented as a, or may be referred to as, an image formation engine or print engine. 
     In response to or based upon commands received via a user interface (e.g. user interface  820  in  FIG. 10B ) and/or via machine readable instructions, controller  802  generates control signals as described above in accordance with at least some of the examples of the present disclosure. In some examples, controller  802  is embodied in a general purpose computing device while in some examples, controller  802  is incorporated into or associated with at least some of the image formation devices, portions, stations, and/or elements along the travel path, developer units, fluid ejection devices, charge sources, liquid removal portions, liquid removal, dryers, transfer stations, user interfaces, instructions, engines, functions, and/or methods, etc. as described throughout examples of the present disclosure. 
     For purposes of this application, in reference to the controller  802 , the term “processor” shall mean a presently developed or future developed processor (or processing resources) that executes sequences of machine readable instructions contained in a memory. In some examples, execution of the sequences of machine readable instructions, such as those provided via memory  810  of control portion  800  cause the processor to perform the above-identified actions, such as operating controller  802  to implement the formation of an image as generally described in (or consistent with) at least some examples of the present disclosure. The machine readable instructions may be loaded in a random access memory (RAM) for execution by the processor from their stored location in a read only memory (ROM), a mass storage device, or some other persistent storage (e.g., non-transitory tangible medium or non-volatile tangible medium), as represented by memory  810 . In some examples, memory  810  comprises a computer readable tangible medium providing non-volatile storage of the machine readable instructions executable by a process of controller  802 . In other examples, hard wired circuitry may be used in place of or in combination with machine readable instructions to implement the functions described. For example, controller  802  may be embodied as part of at least one application-specific integrated circuit (ASIC). In at least some examples, the controller  802  is not limited to any specific combination of hardware circuitry and machine readable instructions, nor limited to any particular source for the machine readable instructions executed by the controller  802 . 
     In some examples, control portion  800  may be entirely implemented within or by a stand-alone device. 
     In some examples, the control portion  800  may be partially implemented in one of the image formation devices and partially implemented in a computing resource separate from, and independent of, the image formation devices but in communication with the image formation devices. For instance, in some examples control portion  800  may be implemented via a server accessible via the cloud and/or other network pathways. In some examples, the control portion  800  may be distributed or apportioned among multiple devices or resources such as among a server, an image formation device, and/or a user interface. 
     In some examples, control portion  800  includes, and/or is in communication with, a user interface  820  as shown in  FIG. 10B . In some examples, user interface  820  comprises a user interface or other display that provides for the simultaneous display, activation, and/or operation of at least some of the image formation devices, stations, portions, elements, user interfaces, instructions, engines, functions, and/or methods, etc. as described in association with  FIGS. 1-10A and 11 . In some examples, at least some portions or aspects of the user interface  820  are provided via a graphical user interface (GUI), and may comprise a display  824  and input  822 . 
       FIG. 11  is a flow diagram schematically representing an example method. In some examples, method  900  may be performed via at least some of the same or substantially the same devices, portions, stations, elements, control portion, user interface, methods, etc. as previously described in association with  FIGS. 1A-10B . In some examples, method  900  may be performed via at least some devices, portions, stations, elements, control portion, user interface, methods, etc. other than those previously described in association with  FIGS. 1A-10B . 
     As shown at  902  of  FIG. 11 , in some examples method  900  comprises applying an electrically charged, semi-liquid image-receiving holder onto a transfer member while at  904 , method  900  comprises ejecting droplets of color ink particles within a dielectric, non-aqueous carrier fluid to form an image on the electrically charged, image-receiving holder supported by the transfer member. As shown at  906 , in some examples method  900  comprises directing airborne charges to charge the color ink particles to induce movement of the charged color ink particles, via attraction relative to the electrically charged, image-receiving holder, through the carrier fluid to become electrostatically fixed relative to the image-receiving holder. As shown at  908 , in some examples method  900  comprises removing liquid, including at least the carrier fluid, from a surface of the electrically charged, image-receiving holder. As shown at  910 , in some examples method  900  comprises transferring the color ink particles of the image and the image-receiving holder together from the transfer member to an image formation medium with the image-receiving holder forming an outermost layer relative to the image formation medium. 
     Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein.