Wash station

Abstract

An electrically powered wash station 201 for cleaning a printhead 105 of a continuous inkjet printer (101, Fig,1). The electrically powered wash station comprises a printhead receiving portion 211 for

Description

The present invention relates to inkjet printing and more particularly to a wash station for cleaning a printhead used in inkjet printing. In particular, a wash station for cleaning a printhead of a continuous inkjet printer. In inkjet printing systems the print is made up of individual droplets of ink generated at a nozzle and propelled towards a substrate. There are two principal systems: drop on demand where ink droplets for printing are generated as and when required; and continuous inkjet printing in which the droplets are continuously produced and only selected ones are directed towards the substrate, the others being recirculated to an ink supply. Continuous inkjet printers supply pressurised ink to a print head drop generator where a continuous jet or stream of ink emanating from a nozzle is stimulated to form individual regular drops by, for example, an oscillating piezoelectric element. The drops are directed past a charge electrode where they are selectively and separately given a predetermined charge before passing through a transverse electric field, which may be provided across a pair of deflection plates (and also known as a deflection electrode). Each charged drop is deflected by the field by an amount that is dependent on its charge magnitude before impinging on the substrate whereas the uncharged drops proceed without deflection and are collected at a gutter from where they are recirculated to the ink supply for reuse. The charged drops bypass the gutter and hit the substrate at a position determined by the charge on the drop and the position of the substrate relative to the print head. Typically, the substrate is moved relative to the print head in one direction and the drops are deflected in a direction generally perpendicular thereto, although the deflection plates may be oriented at an inclination to the perpendicular to compensate for the speed of the substrate (the movement of the substrate relative to the print head between drops arriving means that a line of drops would otherwise not quite extend perpendicularly to the direction of movement of the substrate). In continuous inkjet printing a character may be printed from a matrix comprising a regular array of potential drop positions. Each matrix comprises a plurality of columns (strokes), each being defined by a line comprising a plurality of potential drop positions (e.g. seven) determined by the charge applied to the drops, and various other influencing factors. Thus each usable drop is charged according to its intended position in the stroke. If a particular drop is not to be used the drop is not charged and it is captured at the gutter for recirculation. This cycle repeats for all strokes in a matrix and then starts again for the next character matrix. Ink is delivered under pressure to the print head by an ink supply system that is generally housed within a sealed compartment of a cabinet that includes a separate compartment for control circuitry and a user interface panel. The system includes a main pump that draws the ink from an ink storage tank of the ink supply system via a filter and delivers it under pressure to the print head. As ink is consumed the tank is refilled as necessary from a replaceable ink cartridge that is releasably connected to the tank by a supply conduit. The ink is fed from the tank via a flexible delivery conduit, which may be referred to as an umbilical, to the print head. The unused ink drops captured by the gutter are recirculated to the tank via a return conduit by a pump. The flow of ink in each of the conduits is generally controlled by solenoid valves and / or other like components. Reliable droplet generation (by jet break-up) is contingent on the ink having substantially inviscid properties, so ink in the ink tank is preferably dilute. Ink recirculating from the gutter is solvent-depleted due to evaporation of solvent. Therefore, the ink (storage) tank has its mixture continually adjusted with make-up solvent from a replaceable solvent cartridge to ensure that the ink being drawn from the ink tank has an acceptable viscosity. Various types of inks maybe used within the continuous inkjet printers. The ink may include an organic solvent selected from C1-C4 alcohols, C4-C8 ethers, C3-C6 ketones, C3-C6 esters, and mixtures thereof. Inks may contain different types of colourant. In some circumstances dye based inks are used. Periodic cleaning of the printhead is required since there are various sources of contamination during the printing process; during operation of continuous ink jet printheads, the printhead components are known to become lightly coated with ink and other foreign bodies. The principle causes of the coating are a brief transient spray created as the jet is started and stopped, the continuous albeit very light coating caused by charged microsatellites that are formed during the jet breakoff and charging process, and some splash back from the substrate. According to the ink type and application, the customer is required to clean the printhead on a frequent basis ranging from daily to monthly intervals. The current cleaning process typically involves stopping the ink jet, removing the printhead from the printing location, removing the cover tube or printhead casing from the printhead, placing the printhead in a waste collection vessel, and spraying or pouring solvent onto the contaminated areas of the printhead to clean those areas. This cleaning process tends to be messy for the customer, requires specialist equipment (for example, gloves and glasses etc.), takes a lot of time, requires large quantities of solvent, much of which may go to waste, and if the cleaning process is not performed properly (for example, not performed thoroughly enough and / or on the required time basis) this may lead to printer unreliability. Further, it is undesirable for the customer or operator cleaning the printhead to inhale any solvent vapours that are present when cleaning the printhead. It would therefore be desirable to provide an improved cleaning process for the printhead. According to a first aspect of the present disclosure there is provided an electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the electrically powered wash station comprising: a printhead receiving portion for receiving the printhead to be cleaned; a fluid supply nozzle configured to receive a fluid from a fluid source and supply fluid into the printhead receiving portion to clean the printhead; and an energy storage device configured to store energy for providing electrical power to the wash station. The wash station may comprise one or more components requiring electrical power in order to perform their function. The one or more components may include, but are not limited to, a controller, a control panel, one or more sensors, one or more pumps, one or more valves, and a fan. The energy storage device may be configured to provide electrical power to one or more said components of the wash station that require electrical power. The term “printhead receiving portion” encompasses a region or space of the wash station that the printhead is configured to be located in for cleaning. In particular, the printhead receiving portion may comprise at least one side wall which substantially surrounds the printhead. The at least one side wall may be a side wall of the wash station, or it may be a side wall received within a housing of the wash station. The at least one side wall may be a generally cylindrical side wall. The printhead receiving portion may comprise an opening that allows the printhead to be inserted into the printhead receiving portion. The printhead receiving portion may also comprise an outlet opening to allow any fluid used to clean the printhead to drain through the outlet opening. The term “fluid supply nozzle” encompasses a nozzle or port that is configured to deliver fluid to the printhead receiving portion. The fluid may be delivered as a pressurised fluid. In particular, the fluid delivered may be a jet of liquid and / or gas. The fluid may include a cleaning liquid, which may be a solvent. The cleaning liquid may be selected based upon the type of ink that has been used in the printhead. The fluid may also include a gas, for example air. The term “fluid source” encompasses any suitable fluid source. By way of example, when the fluid is a cleaning liquid, the fluid source may be a container containing the cleaning liquid received within the wash station and / or a main body of the continuous inkjet printer. Likewise, where the fluid is a gas, the fluid source may also be a container containing the gas received within the wash station and / or a main body of the continuous inkjet printer, or the fluid source may simply be the atmosphere. The fluid that is supplied into the printhead receiving portion is used to clean the printhead by removing for example ink and / or unwanted debris such as dust from the printhead. The term “energy storage device” encompasses any suitable type of energy storage device for storing potential energy (e.g. chemical potential energy, elastic potential energy) that can be used to provide electrical power to the relevant components of the wash station. The wash station comprising an energy storage device is advantageous as it allows for the wash station to be moved close to a region where a printhead may be used for printing (e.g. close to a printing operation line). Further, the wash station comprising an energy storage device is advantageous as it enables the wash station to be transported between multiple printing locations easily, allowing a single wash station to be used for cleaning multiple printheads at different locations. Being able to provide the wash station at a location close to where printing takes place reduces the downtime of a printing assembly while cleaning of the printhead occurs. Further, it allows for the wash station to be used at locations where connection to a mains power supply may not readily be available. The energy storage device may comprise a battery. The term “battery” encompasses at least one battery cell. The battery may be a rechargeable battery. The battery may be able to be recharged while installed in the wash station. The battery may be a replaceable battery, such that when the battery is low or has no power it can be removed from the wash station and replaced by a different battery. The removed battery may then be recharged or disposed of. The wash station may comprise two or more batteries, and the wash station may draw power from only one battery at a time. The wash station may be powered via a connection to a mains power supply. Power supplied to the wash station via the mains power supply may be delivered via the one or more batteries. The energy storage device may be configured to provide power to at least one of: a controller; a valve; a pump; a light source; and a fan. That is to say that the energy storage device may be configured to provide power to all of the above listed components, to one of them, or to any combination. It will also be appreciated that the energy storage device may be configured to provide power to a plurality of the same above listed components. By way of example, the energy storage device may be configured to provide power to a plurality of controllers, and / or a plurality of valves, and / or a plurality of pumps; and / or a plurality of light sources; and / or a plurality of fans. The above list of features is not exhaustive. The energy storage device may be configured to provide electrical power to any component of the wash station that requires electrical power. By way of example, the energy storage device, may be configured to provide electrical power to a plurality of sensors and / or a display screen. The term “light source” encompasses any suitable type of light, for example an LED or a plurality of LEDs. The wash station may comprise an external housing and an internal housing. The internal housing may define the printhead receiving portion, and the internal housing may be at least partly received within the external housing. That is to say that the internal housing may be substantially surrounded by the external housing save as for an opening in the internal housing and a corresponding opening in the external housing to permit the printhead to be inserted into the internal housing. The internal housing may also comprise an opening to locate a fan to direct an airflow through the printhead receiving portion. The benefit of providing the printhead receiving portion in an internal housing that is substantially surrounded by an external housing is that it mitigates against a cleaning fluid, in particular solvent and solvent vapours from contacting or being inhaled by a user operating the wash station. The solvent and solvent vapours may be largely contained within at least the external housing. Additionally, the external housing may be used to house various components of the wash station (e.g. pumps, valves, controllers, a fan, solvent containers). Having components of the wash station housed within the external housing mitigates against damage of said components when moving the wash station and mitigates against debris, including dust, from contacting and settling on components located with the external housing. The external housing may comprise a base, one or more side walls extending from the base and a top wall. The top wall and / or the side walls may comprise an opening to allow a printhead for cleaning to be inserted. The top wall and / or side walls may comprise additional openings to allow access to various components of the wash station. In particular, the additional openings may allow a user access to the energy storage device and / or to a container which stores cleaning liquid. The internal housing may comprise a first outlet opening, and the external housing may comprise a second outlet opening. The first outlet opening may be in fluid communication with the second outlet opening. The term “outlet opening” encompasses a hole, a port, an aperture or any other suitable opening that permits the passage of a fluid, in particular a liquid. The first and / or second opening may be provided with a valve to control the flow of fluid through the respective opening. The first outlet opening being in fluid communication with the second outlet opening includes the respective openings being in direct and indirect fluid communication with one another. A cleaning liquid used to clean the printhead may be permitted to pass from the printhead receiving portion to the second outlet opening via the first outlet opening. In use, cleaning liquid may travel along a base of the external housing to the second outlet opening. The base of the external housing may be sloped. The term “cleaning liquid” encompasses any suitable type of liquid for cleaning the printhead, for example a solvent or water. The solvent may be selected based upon the type of ink used in the printhead. In use, the wash station may be orientated so that cleaning liquid may pass through the first outlet opening and the second outlet opening under the action of gravity. In other embodiments, one or more pumps may be used to transport liquid from the printhead receiving portion to the second outlet opening. In some embodiments, the first outlet opening and the second outlet opening may define a single outlet opening. In some embodiments the electrically powered wash station may comprise only one outlet opening. The first outlet opening may be offset from the second outlet opening. That is to say, the first outlet opening and the second outlet opening are offset from one another. As such, the bulk flow direction of liquid passing through the first opening changes direction in order to pass through the second opening. Having the first outlet opening and the second outlet opening spaced apart mitigates against unwanted pooling of cleaning liquid in the internal housing. In particular, the first outlet opening may define a first geometric centre and the second outlet opening may define a second geometric centre and the first geometric centre and the second geometric centre are spaced apart along at least two axes. As such, when the wash station is in use, and using Cartesian coordinates, the first outlet opening and the second outlet opening may be spaced apart in the y-axis (e.g. vertically spaced apart), and spaced apart in the x-axis and / or z-axis. The electrically powered wash station may further comprise a cleaning liquid collection container; and the cleaning liquid collection container may be in fluid communication with the second outlet opening. The cleaning liquid collection container is provided to collect a cleaning liquid that has been used to clean the printhead. The cleaning liquid collection container may be in direct fluid communication with the second outlet opening such that liquid passing through the second outlet opening passes directly into the cleaning liquid collection container. The cleaning liquid collection container may be in fluid communication with the second outlet opening via a fluid channel (e.g. a tube connecting the second outlet opening and the collection container). The external housing may comprise a connection portion that is configured to connect the cleaning liquid collection container. The connection portion may include a threaded portion that is configured to engaged with a corresponding threaded portion of the collection container. A valve may be provided at the second outlet opening. The valve may be configured such that liquid can only pass through the second outlet opening and hence through the valve when the cleaning liquid collection container is connected to the wash station. The cleaning liquid collection container may comprise a sensor to sense when a volume of liquid in the collection container has reached a pre-determined amount. The sensor may include a float sensor. The sensor may be powered by the energy storage device. The electrically powered wash station may comprise a sensor that is configured to sense when a cleaning liquid collection container is connected to the wash station. Said sensor may be powered by the energy storage device. A valve may be provided at the second outlet opening. The valve may control the flow of liquid through the second outlet opening. The valve may be actuated using power supplied from the energy storage device. The first outlet opening may comprise a valve. The valve may control the flow of liquid through the second outlet opening. The valve may be actuated using power supplied from the energy storage device. The valve may be configured to permit the flow of liquid through the second outlet opening when the cleaning liquid collection container is connected to the wash station. This mitigates against liquid that has been used to clean the printhead from leaking or spilling on to an area or floor in the vicinity of the wash station. The fluid supply nozzle may be configured to supply a cleaning liquid into the printhead receiving portion. The electrically powered wash station may further comprise a cleaning liquid supply container which is configured to store cleaning liquid for cleaning the printhead, and the cleaning liquid in the cleaning liquid supply container may be the fluid source. The cleaning liquid supply container may be received in a cleaning liquid supply container portion of the wash station. The cleaning liquid supply container portion may be located within the external housing of the wash station. The cleaning liquid supply container may comprise a septum that is configured to be pierced by a corresponding needle provided in the wash station. The cleaning liquid container is in fluid communication with the fluid supply nozzle. The wash station having its own cleaning liquid supply is advantageous as it mitigates against the need for the wash station to be connected to an external fluid supply source, thus allowing the wash station to be entirely portable. Further, when the cleaning liquid supply container is empty or low on fluid it can readily be replaced by another cleaning liquid supply container, and in some embodiments a user may be able to refill the cleaning liquid supply container with cleaning liquid. There may be one or more sensors configured to determine the presence of the cleaning liquid supply container in wash station. The one or more sensors may be powered by the energy storage device. There may be one or more sensors configured to the volume of liquid in the cleaning liquid supply container. The one or more sensors may be powered by the energy storage device. The wash station may comprise a pump that is configured to pump cleaning liquid from the cleaning liquid container to the fluid supply nozzle. The cleaning liquid may be supplied to the fluid supply nozzle under the action of gravity. The electrically powered wash station may further comprise a cleaning liquid supply channel configured to receive cleaning liquid from the printhead; and the cleaning liquid supply channel may be configured to supply cleaning liquid to the fluid supply nozzle. That is to say that cleaning liquid may be supplied to the wash station via the print head. In particular, the printhead in use may remain connected via an umbilical to a main body of a printer. The main body of the printer may comprise an ink source and a solvent source that are used during printing. When the printhead is received in the wash station, the printer may be configured to deliver solvent from the solvent source in the main body of the printer to wash station via a nozzle of the printhead, and said solvent is a cleaning liquid. The cleaning liquid supply channel may then supply said solvent directly to the fluid supply nozzles, or the cleaning liquid supply channel may supply said solvent to a cleaning liquid supply container. Providing solvent from the printer to clean the printhead is advantageous as it mitigates against the need for the wash station to have its own cleaning liquid supply. Further, even if the wash station has its own cleaning liquid supply container, it may still be advantageous to supply solvent from the printer as the cleaning liquid if a different type of solvent to what is in the cleaning liquid supply container is required, or if there is not an adequate volume of cleaning liquid in the cleaning liquid supply container. The fluid supply nozzle may be configured to supply a pressurised gas into the printhead receiving portion. The term “pressurised” encompasses a pressure that is greater than the ambient surrounding pressure in the wash station. Pressurised gas that is supplied may be used to disturb and distribute a cleaning liquid that is delivered into the printhead receiving portion. In particular, the pressurised gas may be used to distribute cleaning fluid delivered via a nozzle of the printhead. By distributing the cleaning fluid using a pressurised gas the cleaning of the printhead may be improved. The pressurised gas may also be used to assist with drying of the printhead and / or the printhead receiving portion. The electrically powered wash station may comprise a plurality of fluid supply nozzles. The printhead receiving portion may define a central axis. The plurality of fluid supply nozzles may be configured to direct a fluid generally towards the central axis, and the plurality of fluid supply nozzles may be spaced apart about the central axis. The printhead receiving portion may be a generally cylindrical portion and the central axis is the axis of the cylindrical portion. Where the printhead receiving portion is not a generally cylindrical portion, the central axis is an axis that generally follows a centreline of the printhead receiving portion. Each of the plurality of fluid nozzles may be arranged at a different angle with respect to the central axis. This is so in use the fluid nozzles may be arranged to target specific components of a continuous inkjet printhead (for example, the nozzle, charge electrode, deflection electrode, and gutter). The electrically powered wash station may comprise at least four nozzles. The term “the plurality of fluid nozzles are spaced apart about the central axis” encompasses the fluid nozzles being disposed around the central axis. The plurality of nozzles may be non-equally angularly spaced about the central axis. The plurality of nozzles may be provided at different axial heights with respect to the central axis. Providing the plurality of nozzles at different axial heights may improve cleaning of the printhead, by being able to more accurately clean the desired regions of the printhead. At least one of the plurality of fluid supply nozzles may be configured to supply a cleaning liquid into the printhead receiving portion. At least one of the plurality of fluid supply nozzles may be configured to supply a pressurised gas into the printhead receiving portion. According to a second aspect of the present disclosure there is provided an electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the printhead comprising: a nozzle for ejecting droplets of ink; a charge electrode for selectively charging the droplets of ink ejected from the nozzle; a deflection electrode for deflecting the charged droplets of ink; and a gutter for collecting uncharged droplets of ink; the electrically powered wash station comprising: a printhead receiving portion for receiving the printhead to be cleaned; a cleaning liquid supply container configured to store cleaning liquid for cleaning the printhead; a fluid supply nozzle configured to receive cleaning liquid from the cleaning liquid supply container and to direct the cleaning liquid into the printhead receiving portion; an electrically powered pump configured to pump cleaning liquid from the cleaning liquid supply container to the fluid supply nozzle; and a battery configured to provide electrical power to at least the pump. The electrically powered wash station may further comprise a fan configured to generate an airflow in the printhead receiving portion; and wherein the battery is configured to provide power to the fan. The electrically powered wash station may further comprise a controller and a light source; and the battery may be configured to provide electrical power to the controller and the light source. According to a third aspect of the present disclosure there is provided a method for operating an electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the method comprising: storing a cleaning liquid in a cleaning liquid supply container of the electrically powered wash station; powering a pump using a battery; pumping the cleaning liquid from the cleaning liquid supply container to a fluid supply nozzle; supplying cleaning fluid via the fluid supply nozzle into a printhead receiving portion of the electrically powered wash station to clean the printhead. The method may further comprise: powering a fan using the battery and generating an airflow in the printhead receiving portion. The method may further comprise inserting a printhead of a continuous inkjet printer into the printhead receiving portion. Optional and / or preferred features as set out herein may be used either individually or in combination with each other where appropriate and particularly in the combinations as set out in the accompanying claims. The optional and / or preferred features for each aspect of the disclosure set out herein are also applicable to any other aspects of the disclosure, where appropriate. For example, it will be appreciated that any of the first aspect may be combined with the second aspect, and that the method of the third may be used with the first and / or second aspects. Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 schematically illustrates a continuous inkjet printer; Figure 2 shows an exploded schematic diagram of the printhead of the continuous inkjet printer of Figure 1; Figure 3 shows a schematic perspective view of a wash station according to the present invention; Figure 4 shows a schematic cross-sectional view of the wash station of Figure 3; Figure 5 shows a flow chart of a method of operating a wash station; Figure 6 shows a schematic cross-sectional view of another wash station; and Figure 7 shows a schematic cross-sectional view of another wash station. It will be appreciated that the drawings are for illustration purposes only and may not be drawn to scale. Figure 1 schematically illustrates an inkjet printer 101. The printer 101 comprises a printer main body 103 connected to printhead 105 by an umbilical cable 107. The printer main body 103 may comprise the ink supply system and a printer controller, and the printer main body 103 may have a display 109 (e.g. a touchscreen) for use by an operator. The printhead 105 is arranged to print on a substrate, such as the surface of an item 111, moving along a production line 113. Figure 2 is an exploded schematic diagram of the printhead 105 of the continuous inkjet printer 101 of Figure 1. The printhead 105 comprises a droplet generator 115. Ink is provided to the droplet generator 115 under pressure from the printer main body 103 and is forced through a nozzle of the droplet generator 115 to form an inkjet 117. The inkjet 117. The inkjet 117 begins as a constant stream of ink and, under the influence of surface tension and vibrations applied in the droplet generator 115 (e.g. by a piezoelectric oscillator), gradually separates into a series of ink droplets 119 which continue to travel in the direction of the inkjet 117. Shortly after emerging from the nozzle of the droplet generator 115, the ink jet 117 is passed through a charge electrode 121. The point at which the continuous inkjet 117 separates into droplets 119 is arranged to occur within the charge electrode 121. The ink is an electrically conductive liquid, and the droplet generator is conventionally held at a fixed (e.g. ground) potential. A variable voltage is applied to the charge electrode 121 causing charge to be induced on the continuous stream of ink extending from the ink droplet generator 115 towards the charge electrode 121 As the continuous stream of ink (i.e. inkjet 117) separates into droplets 119, any charge induced on the ink within the droplet becomes trapped at the moment the individual droplet breaks off from the main stream of ink 117. In this way, a variable charge can be applied to each of the ink droplets within the stream of ink droplets 119. The stream of ink droplets 119 then continues to pass from the charge electrode 121 and through an electrostatic field. In the illustrated example, the stream of ink droplets 119 passes between deflection electrodes 123, 125. A first one of the deflection electrodes 123 is held at a first voltage, whereas the second one of the deflection electrodes 125 is held at second voltage, with a large potential difference (e.g. 8-10 kilovolts) established between the deflection electrodes 123, 125. In some systems, one electrode may be maintained at a ground potential while the other electrode is held at a high (positive or negative) voltage (with respect to ground). In other systems, one electrode is held at a negative voltage (with respect to ground) and the other electrode is held at a positive voltage (with respect to ground). In a further alternative, only a single deflection electrode, or a plurality of deflection electrodes, are provided. The field established by the deflection electrodes 123, 125 causes any charged droplets (i.e. those that have been charged by the charge electrode 121) to be deflected. In this way, based upon the variable charge applied by electrode 121, the droplets 159 can be selectively (and variably) steered from the path along which they are emitted from the nozzle of the droplet generator 115. Droplets which pass through the deflection field without being deflected travel to a gutter 127. The gutter 127 comprises an orifice into which the droplets enter. The gutter 127 is connected to a gutter line which extends from the gutter back to the ink supply system. The printhead 105 further comprises a printhead cover tube 129. The printhead cover tube 129 is configured to be placed over the components 115, 121, 123, 125, 127 of the printhead 105 while the printhead 105 is printing. The cover tube 129 comprises an end face 131 with an opening 133. The opening 133 permits the passage of droplets of ink 119 that are to be printed onto a substrate. The cover tube 129 is removable to permit cleaning of the printhead 105 and / or cleaning of the cover tube 129. Figure 3 shows a schematic perspective view of a wash station 201. The wash station 201 is an electrically powered wash station that is used to clean the printhead 105. In particular, the wash station 201 is used to clean the printhead 105 with the cover tube 129 removed. The wash station 201 comprises an external housing 203. The external housing 203 comprises a base 205, four side walls 207 (only two side walls are visible) extending upwards from the base portion 205 in the orientation shown in Figure 3. The external housing 203 further comprises a top wall 209 extending between the side walls 207. The external housing 203 defines an internal space in which components of the wash station 201 are located (shown in Figure 4). It will be appreciated that the external housing 203 may take any suitable shape. The external housing 203 may be detachably mounted to a stand (not shown) to allow ease of movement of the wash station 201 to various printing locations. In particular, the stand may comprise a pole which the wash station is configured to be mounted to. The wash station may be able to be mounted to the pole at various locations. That is to say, the wash station may be mounted to the pole at different heights. Further, the stand may comprise a base which the pole extends from in a generally vertical direction. The base may comprise wheels to allow the stand and hence wash station to be easily transported to a desired location. In some embodiments, the wash station 201 may be arranged to be detachably mounted to a wall of a main body of a printer that the printhead 105 is connected to. The wash station may have a handle. The handle may allow an operator to easily carry the wash station. The wash station 201 comprises a print head receiving portion 211. The printhead receiving portion 211 is a region of the internal space defined by the external housing 203 that is configured to receive the printhead 105 to be cleaned by the wash station 201. As better seen in Figure 4, the wash station 201 further comprises an internal housing 213 which defines the printhead receiving portion 211. The top wall 209 of the external housing 203 comprises an opening 215 which is sized to allow a user to insert and remove the printhead 105 into the printhead receiving portion 211. The opening 215 may be sized such that the printhead 105 can only be inserted when the printhead cover tube 129 is removed. The wash station 201 comprises an additional opening 217 in the top wall 209. The additional opening 217 is an opening which allows a user to access a cleaning liquid supply container receiving portion 219. The cleaning liquid supply container receiving portion 219 is a region of the wash station 201 that is configured to receive a container that holds cleaning liquid for cleaning the printhead 105. A cover 221 is provided for covering the opening 217. In Figure 3, the cover 221 is shown in a partially open state. The cover 221 is a simple flap cover that is able to rotate about a hinge 223. The cover 221 is provided to mitigate against unwanted particulates (e.g. dust and debris) from entering the wash station 201. The cover 221 is an optional feature and may not present in other embodiments. The wash station 201 further comprises a cover 225 which covers another opening (not visible) in the top wall 209. This other opening is an opening which allows a user to access a battery receiving portion of the wash station 201. The battery receiving portion is configured to receive a battery than can be used to supply power to various components of the wash station 201. As with the cover 221, the cover 225 is provided to mitigate against unwanted particulates (e.g. dust and debris) from entering the wash station 201. The cover 225 is shown in a closed position in Figure 3. The cover 225 may be opened by rotating it about its hinges 227. The cover 225 is an optional feature and may not present in other embodiments. The covers 221, 225 may be able to be secured to the wash station with simple locking mechanisms (e.g. a latch) so as to prevent the covers 221, 225 from opening. The covers 221, 225, may have more advanced locking mechanisms that only allow the covers 221, 225 to be opened when the wash station 201 is not in use (i.e. is not performing a cleaning operation). In some embodiments either or both of the covers 221, 225 may not be provided. It could be desirable to provide a cover at the opening 215 of the printhead receiving portion 211. Further, because the printhead 105 remains attached to the umbilical while it is being cleaned it would be difficult to provide a cover 221, 225 of the type shown to cover the battery receiving portion and the cleaning liquid supply container receiving portion 219. The wash station 201 may comprise a cap or completely removable cover that can be placed over the opening 215 when the wash station 201 is not in use. In some embodiments, all covers (including covers 211, 225) may be completely removable and replaceable (i.e. detachable) from the wash station. In some embodiments only some of the covers may be completely removable and replaceable from the wash station. The wash station 201 further comprises an interface 229. The interface 229 is a human-machine interface, which allows an operator to control the wash station 201 and also indicates to the operator various statuses of the wash station 201. In particular, the interface 229 comprises a start button 231 and a stop button 233. Pressing of the start button 231 starts a cleaning cycle of the wash station. Pressing of the stop button 233 stops a cleaning cycle. The start button 231 may also be used to power on the wash station 201. In other embodiments, the interface 229 may comprise an additional power-on button. In addition to the interface 229 or as an alternative, in other embodiments the wash station 201 may be able to be remotely controlled, for example via a printer, a mobile device, remote control, or a computer. In some embodiments, the wash station 201 may automatically power on when a printhead 205 is inserted into the printhead receiving portion 211. The interface 229 further comprises a plurality of light indicators 235 (e.g. light emitting diodes, LEDs). One or more symbols may be provided on the interface 229 adjacent a light indicator 235, to allow an operator to understand what the light indicator represents. Although four light indicators 235 are shown on the embodiment in Figure 3, the wash station 201 may comprise more or less light indicators 235. A light indicator 235 may be provided to indicate that the wash station is powered on, for example by a green light. The same light indicator 235 may also be used to indicate that the battery is low on power, for example by a flashing red light. Alternatively, a different light indicator 235 may be provided to show a charge status of the battery. One or more light indicators 235 may be provided to indicate to an operator the type of wash (cleaning cycle) that is to be performed. For example, the wash station 201 may be able to perform a short wash, a medium wash or a long wash. An additional button may be provided on the interface 229 to allow an operator to select the type of wash to be performed. A light indicator 235 may be provided to indicate that the cleaning liquid supply container requires replacing, or that the supply container requires replenishing. A light indicator 235 may also be provided to indicate that there is no cleaning liquid supply container present in the wash station. The interface 229 may in some embodiments comprise a button that allows an operator after replacing or replenishing the cleaning liquid supply container to re-set the light indicator 235. In some embodiments, the light indicator 235 may reset automatically. As described in relation to Figure 4, the wash station 201 may comprise a cleaning liquid collection container to collect cleaning liquid that has been used to clean the printhead 105. Accordingly, the interface 229 may comprise one or more light indicators 235 to indicate the volume or liquid in the cleaning liquid collection container or that the cleaning liquid collection container requires emptying and / or replacing. A light indicator 235 may also be provided to indicate that there is no cleaning liquid collection container present. The interface 229 may in some embodiments comprise a button that allows an operator after replacing or emptying the cleaning liquid collection container to re-set the light indicator 235. In some embodiments, the light indicator 235 may reset automatically. The interface 229 may comprise a light indicator 235 to indicate that washing of the printhead 105 is taking place or is complete. In some embodiments, where the wash station 201 is also arranged to dry the printhead 105, a light indicator 235 may be provided to show that drying is either taking place or is complete. The interface 229 is described as having a plurality and buttons and light indicators. However, the interface 229 may take any suitable form. For example, the interface 229 may be a combination of a display screen and buttons, or the interface 229 may be a touch screen. In some embodiments, the interface 229 may comprise light indicators and / or a display screen but may not allow any direct operator input. That is to say the operator may control the wash station remotely from a device that is connected (wirelessly or by a wire) to the wash station 201. The wash station 201 further comprises a power supply interface 237. The power supply interface 237 permits connection of the wash station 201 to an external power supply, for example a mains power supply. The power supply interface 237 may be used as an alternative to the battery to provide electrical power to the wash station 201. The power supply interface 237 may be used to provide power to recharge the battery where the battery is a rechargeable battery. The interface 229 and power supply interface 237 are both shown in Figure 3 as being provided on the same side wall 207, in particular a front side wall. The interface 229 and power supply interface 237 may be provided at any suitable location on the wash station 201, and there is no requirement for the interface 229 and power supply interface 237 to be located adjacent one another. Figure 4 shows a schematic cross-sectional view of the wash station shown in Figure 3. In particular, Figure 4 shows the wash station 201 with the printhead 105 located in the printhead receiving portion 211. The wash station 201 comprises a plurality of fluid supply nozzles 239. The fluid supply nozzles 239 are configured to supply a cleaning fluid into the printhead receiving portion 211 in order to clean the printhead 105. In particular, in the embodiment shown in Figure 4, the fluid supply nozzles 239 are configured to receive a cleaning liquid from a cleaning liquid supply container 241 that is located in the cleaning liquid supply container receiving portion 219. The cleaning liquid provided in the cleaning liquid supply container 241 may be any suitable liquid for cleaning the printhead 105. In particular, the cleaning liquid may comprise a solvent. The cleaning liquid may be selected based upon the type of ink that has been used in the printhead 105. A pump 243 is provided to pump cleaning liquid from the cleaning liquid supply container 219 to the fluid supply nozzles 239. There may also be a compressor / blower provided to allow pressurised air to be provided to the fluid supply nozzles 239. When cleaning liquid is supplied from the fluid supply nozzles 239 into the printhead receiving portion 211 the cleaning liquid is generally supplied as a pressurised liquid such that it is ejected from the fluid supply nozzles 239 as a jet. Providing the cleaning liquid as jets into the printhead receiving portion 211 promotes cleaning of the printhead 105. Providing the cleaning liquid as jets may reduce the volume of cleaning liquid that is required to clean the printhead 105 and / or reduce the time taken to clean the printhead 105. Cleaning liquid that is supplied into the printhead receiving portion 211 leaves the printhead receiving portion 211 via an outlet opening 240. The outlet opening 240 is an opening in the internal housing 213 which permits the passage of liquid from the printhead retaining portion 211 in to the internal space of the wash station 201 enclosed by the external housing 203. In the embodiment shown the cleaning liquid can pass through the outlet opening 240 under the action of gravity. In other embodiments a vacuum may be provided to promote removal of cleaning liquid from the printhead receiving portion 211. The outlet opening 240 is spaced apart from the base 205 of the external housing 203, this mitigates against pooling of liquid in the printhead receiving portion 211. In other embodiments it may be desirable to fill the printhead receiving portion with cleaning liquid for a period of time. In such cases, a valve or a restriction (e.g. a narrow opening) may be provided at the outlet opening 240 to control the flow (e.g. limit the flow rate) of cleaning liquid through the outlet opening 240. In embodiments where the printhead receiving portion 211 can be filled with cleaning liquid, to promote cleaning of the printhead 105 an agitator may be provided to agitate the cleaning liquid in the printhead receiving portion 211. In Figure 4, three fluid supply nozzles 239 are visible. However, the wash station 201 comprises additional fluid supply nozzles 239. In particular, the wash station 201 comprises a fluid supply nozzle 239 for each part of the printhead 105 to be cleaned. That is to say, the wash station 201 comprises: a fluid supply nozzle 239 that is arranged to supply cleaning fluid towards the gutter 127; a fluid supply nozzle 239 that is arranged to supply cleaning fluid towards the deflection electrodes 123, 125; a fluid supply nozzle 239 that is arranged to supply cleaning fluid towards charge electrode 121; and a fluid supply nozzle 239 that is arranged to supply cleaning fluid towards drop generator 115 and nozzle. In other embodiments, the number of fluid supply nozzles 239 may be more or less. The printhead receiving portion 211 may comprise an alignment or guide feature. The alignment or guide feature may comprise a protrusion and / or a recess that is complementary to a corresponding recess and / or protrusion on the printhead 105. The printhead 105 may only be inserted into the printhead receiving portion 211 if the protrusion and / or a recess of the guide feature aligns with and cooperates with the corresponding recess and / or protrusion on the printhead 105. In particular, the printhead 105 may comprise a fastener that is provided to engage with the printhead cover 129. The alignment or guide feature of the printhead receiving portion 211 may be configured to receive the fastener of the printhead 105. The alignment or guide feature may be provided at the opening 215 of the printhead receiving portion 211. The alignment or guide feature may be provided to ensure that the printhead 105 is always inserted in the printhead receiving portion 211 in the same orientation. By ensuring that the printhead 105 is always inserted in the printhead receiving portion 211 in the same orientation the fluid supply nozzles 239 can be arranged to accurately direct cleaning liquid to the specific components of the printhead 105. The fluid supply nozzles 239 are generally disposed around a central axis 245 of the printhead receiving portion 211. The fluid supply nozzles 239 are axially spaced relative to the central axis 245 and also angularly spaced about the axis 245. Providing the fluid supply nozzles 239 at different locations in the printhead receiving portion 211 further aids in cleaning of the printhead 105. The fluid supply nozzles 239 may also be provided at different angles relative to the central axis 245 to allow accurate direction of the cleaning fluid onto the components of the printhead 105. As already described, but only visible in Figure 4, the wash station 201 comprises a battery 247 located in a battery receiving portion 249 for providing electrical power. Electrical power is provided to the pump 243 by the battery 247. The battery 247 may be a 24 V battery. The battery 247 may be a Lithium-ion battery. The battery 247 may be a rechargeable battery. The battery 247 may store enough energy to power the wash station for between around 50 hours to around 70 hours. The battery 247 may store enough energy to power the wash station for around 60 hours. Further, the interface 229 may comprise a light indicator to indicate when the battery 247 is running low on energy. For example, the interface 229 may indicate to the operator when the battery 247 has less than 10 hours remaining. The interface 229 may indicate to the operator when the battery 247 have less than 5 hours remaining. Although a battery 247 is shown as the power supply in the wash station 201. The wash station 201 may comprise any suitable energy storage device for providing power to electrically powered components of the wash station 201. By way of example, an energy storage device may include a spring that can be wound up by an operator. The wound spring can then be used to turn a generator to provide power to the electrically powered components of the wash station 201. The wound spring may in some embodiments be used to provide mechanical power to a pump. In this case the battery receiving portion 249 may be referred to as an energy storage device receiving portion 249. In addition to the battery 247 providing power to the pump 243, the battery 247 is arranged to provide power to the interface 229, a controller 251, a fan 253, and various sensors. The controller 251 is provided within the internal space defined by external housing 203 of the wash station 201. The controller 251 is configured to receive power from the battery 245 and is arranged to communicate with at least the fan 253, pump 243 and the interface 229 of the wash station. The controller 251 is arranged to receive input signals from the interface 229 (e.g. start a cleaning cycle, stop a cleaning cycle) and control various components of the wash station 201 based upon the input signals received. The controller 251 may be arranged to receive input signals from an external device such as a mobile phone or computer, from the printhead, and / or from a controller of a main body of continuous inkjet printer. The controller 251 may be configured to receive information including but not limited to, the type of ink that has been used in the printhead 105 and the period of time that has passed since the printhead 105 was last cleaned. The controller 251 may also be configured to receive information about the type of cleaning liquid that is provided in the cleaning liquid supply container 241. The controller 251 may be able to determine if the cleaning liquid in the cleaning supply container 241 is suitable for cleaning the printhead 105 that is received in the printhead receiving portion 211. If the controller 251 determines that the cleaning liquid is not suitable, the controller 251 may prevent a cleaning cycle from starting. As mentioned above, the wash station comprises a fan 253. The fan 253 is primarily used to assist with drying of the printhead 105 after the printhead 105 has been cleaned by causing air flow in the printhead receiving portion 211. In some embodiments, the fan 253 may operate while the printhead 105 is being cleaned with cleaning liquid. In this instance, the air flow generated by the fan 253 may assist in dispersing cleaning liquid to clean the printhead 105. The fan 253 is located within the external housing 203 of the wash station 201. The internal housing 213 comprises an opening 255 in its wall that the fan 253 is located adjacent to. Accordingly, the fan 253 causes air flow through the opening 255 and through the printhead receiving portion 211. The fan 253 receives electrical power from the battery 245, and is controlled by the controller 251. For example, the controller 251 may be arranged to control when the fan 251 is powered on and off, the time that the fan 251 is run for, and / or the speed at which the fan 251 is run at. The time and / or speed that the fan 251 is run at may be dependent on the length of time taken to clean the printhead 105; the type of ink used in the printhead 105; the operating temperature of the printhead 105; the ambient temperature; and / or the type of cleaning liquid that was used to clean the printhead 105. The wash station 201 comprises various sensors. The wash station 201 comprises a print head presence sensor 257. The printhead presence sensor 257 is arranged to sense whether the printhead 105 is located in the printhead receiving portion 211. The printhead presence sensor 257 may be any suitable type of sensor. For example, the print head presence sensor 257 may be a proximity sensor, e.g. a photoelectric sensor The printhead presence sensor 257 may comprise a switch (e.g. a sprung switch), whereby when the printhead 105 is removed the switch may break a power circuit. The controller 251 is configured to receive signals from the printhead presence sensor 257. The controller 251 may be configured to prevent a cleaning cycle taking place if no printhead 105 is present. Further, if the printhead 105 is removed during a cleaning cycle, the printhead presence sensor 251 may sense this, and the controller 251 may interrupt (e.g. stop) the cleaning cycle. In some embodiments the wash station 201 may not comprise a printhead presence sensor 257. The wash station 201 further comprises a cleaning liquid supply container presence sensor 259. The supply container presence sensor 259 is arranged to determine if a cleaning liquid supply container 241 is provided in the cleaning liquid supply container receiving portion 219. The sensor 259 or an additional sensor (e.g. an RFID reader) may be able to determine the type of cleaning liquid in the container 241 and communicate this information to the controller. If no supply container 241 is present and / or if the type of cleaning liquid in the supply container is not suitable, the controller 251 may be arranged to alert the operator. The controller 251 may alert the operator via the interface 229. In some embodiments the wash station 201 may not comprise a cleaning liquid supply container presence sensor 259. A sensor may be further provided to determine the volume of cleaning liquid in the cleaning liquid supply container 241. If the volume of liquid in the cleaning liquid supply container 241 reaches below a predetermined level the controller 251 may be arranged to alert the operator that the cleaning liquid supply container 241 needs replacing or replenishing. The wash station 201 further comprises a second outlet opening 261 in the base 205 of the external housing 203. The second outlet opening 261 is provided to permit the passage of cleaning liquid out of the wash station 201. Put another way, the outlet opening 240 defines a first geometric centre which lies on the central axis 245, and the second outlet opening 261 defines a second geometric centre. Using Cartesian coordinates the second geometric centre is spaced apart from the first geometric centre in the y-axis (e.g. vertically spaced apart) and in the x-axis (e.g. horizontally spaced apart). The second outlet opening 261 is offset from the outlet opening 240 of the internal housing 213. That is to say that a central axis through the second outlet opening 261 is not coincident with the central axis 245 of the printhead receiving portion. A cleaning liquid collection container 263 is provided at the second outlet opening 261 and is configured to receive cleaning liquid from the wash station 201. The collection container 263 may be sized to hold a volume of cleaning fluid that is equal to or greater than the volume of fluid that can be held in the cleaning liquid supply container 241. The collection container 263 is arranged to releasably engage with the base 205 of the external housing 203 at the opening 261. The collection container 263 may comprise a threaded portion that is configured to engage with a corresponding threaded portion of the external housing 203. The collection container 263 may engage with the base 205 using a latch mechanism or any other suitable type of releasable mechanical engagement mechanism. The collection container 263 is shown to be in direct communication with the opening 261. In other embodiments the collection container 263 may be spaced apart from the opening and a tube may be provided between the opening 261 and the collection container 263 to permit the passage of liquid between the opening 261 and the collection container 263. To prevent cleaning liquid from passing through the opening 261 when no collection container 263 is present a valve 265 is provided at the opening 261. The valve 265 inhibits the passage of cleaning liquid through the opening 261 when no collection container 263 is present. That is to say, when no collection container 263 is present the valve 265 is in a closed configuration. When a collection container 263 is present the valve 265 transitions to an open configuration and permits the flow of liquid through the opening 261 into the collection container 263. The valve 265 may comprise a spring which is arranged to retain the valve 265 in a normally closed configuration. In the normally closed configuration, the valve 265 substantially prevents liquid from passing through the opening 261. The valve 265 may be configured to transition from a normally closed configuration to an open configuration by engaging the collection container 263 with the base 205. In particular, a portion of the collection container 261 may act as an actuator to move a portion of the valve 263 (e.g. a stopper) and said movement transitions the valve 265 into the open configuration. Likewise, if the collection container 263 is removed, the spring may cause the valve 265 to return to the closed configuration, and substantially prevents liquid from passing through the opening 261. In other embodiments, transitioning of the valve 265 between an open and closed configuration may be controlled by the controller 251. Although not shown in the figures, a filter may be provided in the cleaning liquid collection container 263 and / or at the second outlet opening 261. A filter may be provided at the outlet opening 240. The filter(s) may be arranged to filter the cleaning liquid that has been used to clean the printhead 105. Filtering of the cleaning liquid may allow for the cleaning liquid to be re-used to clean the same printhead 105 and / or a different printhead. In some embodiments, a liquid supply line and pump may be provided between the cleaning liquid collection container 263 and the cleaning liquid supply container 241 to allow the used cleaning liquid to be recycled and re-used by transporting liquid from the collection container 263 to the supply container 241. In some embodiments, a supply line may be provided between the internal space of the housing directly to the cleaning liquid supply container 241, such that the cleaning liquid does not pass to the cleaning liquid collection container 263. Further provided is a cleaning liquid collection container presence sensor 267. The collection container presence sensor 267 is arranged to determine if a cleaning liquid collection container 263 is provided to collect cleaning liquid that has been used to clean the printhead 105. If no collection container 263 is present, the controller 251 may be arranged to alert the operator. The controller 251 may alert the operator via the interface 229. If no collection container 263 is present, the controller 251 may prevent a cleaning cycle from taking place. In some embodiments the wash station 201 may not comprise a cleaning liquid supply container presence sensor 267. Another sensor may be provided to determine the volume of cleaning liquid in the cleaning liquid collection container 263. If the volume of liquid in the cleaning liquid collection container 263 reaches above a predetermined level the controller 251 may be arranged to alert the operator that the cleaning liquid collection container 263 needs replacing or emptying. The wash station 201 further comprises a Radio-Frequency Identification (RFID) reader 269. The RFID reader 269 may comprise a scanning antenna and a transceiver. The cleaning liquid supply container 241 may comprise an RFID tag which includes a transponder, in particular it may be a passive transponder. The RFID tag on the cleaning liquid supply container 241 may include information about the type of cleaning liquid in the cleaning liquid supply container 241 and the volume of liquid that the cleaning liquid supply container 241 can hold. When the cleaning liquid supply container 241 is provided in the cleaning liquid supply container receiving portion 219, the RFID reader 269 may be able to confirm the presence of the cleaning liquid supply container 241 and obtain information about the cleaning liquid supply container 241. The information obtained may then be transmitted to the controller 251. The RFID reader 269 may also be used to determine the type of printhead 105 that is received in the printhead receiving portion. The RFID reader may be used to obtain information about the solvent collection container 263 (e.g. the volume of liquid that the solvent container 263 can hold). The RFID reader 269 is an optional feature and may not present in other embodiments. A method of operating the wash station and a cleaning cycle will now be described an illustrated in Figure 5. At step S1, if the wash station 201 is not powered on, an operator may first do this, either by pressing an appropriate button on the interface 229 or remotely turning the wash station 201 on via an external device (e.g. printer, smartphone, computer, or a remote). In some embodiments, insertion of the printhead 105 into the printhead receiving portion 211 may cause the wash station 201 to power on. Prior to step S1 if the wash station is not in the desired location, the operator may move the wash station to a desired location for cleaning a printhead. Once the wash station is powered on the operator may check the status of the wash station (step S2). In particular, the operator checks the light indicators 235 of the user interface to confirm that the cleaning liquid collection container 263 does not need emptying or replacing. The operator may check the light indicators 235 of the user interface to confirm that the cleaning liquid supply bottle 241 contains sufficient cleaning liquid and does not require replenishment or replacing. If the light indicators 235 show that cleaning liquid collection container 263 and the cleaning liquid supply bottle 241 are acceptable the user interface may display green lights next to appropriate symbols and the operator can proceed to step S3. If, however, the cleaning liquid collection container 263 and / or the cleaning liquid supply bottle 241 require emptying / replenishing, the operator may do this at step S21. Once the cleaning liquid collection container 263 and / or the cleaning liquid supply bottle 241 have been emptied and / or replenished the operator can return to step S2. At step S3 the operator places the printhead 105 into the printhead receiving portion 211. In some embodiments, the operator may place the printhead into the print head receiving portion 211 prior to step S1 or S2, in this case the operator may proceed directly to step S4. At step S4 the operator selects a cleaning cycle to be performed (e.g. a short, medium or long cleaning cycle). The short cleaning cycle may use less liquid and perform cleaning for a shorter time than the medium or long cleaning cycle. The operator may select the cleaning cycle dependent upon how soiled they perceive the printhead to be, and / or how long the printhead has been in operation since its previous clean. Further, the cleaning cycle may be selected based upon the type of ink used in the printhead. The user interface 229 may show the operator which cleaning cycle is selected through use of one or more light indicators 235 The operator then at step S41 determines if a drying cycle is required following cleaning of the printhead. If no drying cycle is required they may then proceed to step S5. If a drying cycle is required they operator selects drying cycle at step S42, and then proceed to step S5. It will be appreciated that in some embodiments an operator may be able to select a drying cycle only cycle (i.e. perfume drying without performing cleaning first). At step S5 the operator presses the start button 231 and the wash station begins the cleaning process as selected in step S4 and optionally S42. In particular, cleaning liquid is pumped by the pump 243 to the fluid supply nozzles 239. Cleaning liquid is supplied via the fluid supply nozzles 239 into the printhead receiving portion 211. The cleaning liquid may be supplied as a continuous stream / jet of liquid, as pulses of streams / jets of liquid, as a spray or any combination. For example, a sequence may include jetting the printhead with cleaning liquid from the fluid supply nozzles 239, and then spraying the printhead with cleaning liquid from the fluid supply nozzles 239. The cleaning liquid may be supplied for a predetermined amount of time dependent on the cleaning cycle selected by the operator. The cleaning liquid supplied from the fluid supply nozzles 239 hits the printhead 105 and in doing so removes ink, dust, and or debris from the printhead 105. The cleaning liquid and any ink, dust, or debris then falls through the outlet opening 240 and into the region of the wash station 201 defined by the external housing 203. Once the cleaning cycle has finished (i.e. the fluid supply nozzles stop ejecting cleaning fluid). If the operator has selected to perform drying of the printhead at step S42, the fan 253 may be powered to cause an air flow through the printhead receiving portion 211 and assist in drying the printhead 105. This may be referred to as the drying cycle. In addition to the fan 253 assisting with drying of the printhead 105, at least one of the fluid supply nozzles 239 may be configured to deliver pressurised air into the printhead receiving portion 211. That is to say that at least one of the fluid supply nozzles may be configured to deliver cleaning liquid and / or pressurised air into the printhead receiving portion. The wash station 201 may comprise a fluid supply nozzle 239 that is configured to deliver only a liquid. The wash station 201 may comprise a fluid supply nozzle 239 that is configured to deliver only a gas (e.g. air). As already described, the drying cycle may be an optional step. When the drying cycle is taking place this may be indicated to an operator on the interface 229. For example, this may be indicated to the operator by lighting up a light indicator 235. This may be the same light indicator 235 used to indicate that the cleaning cycle is taking place, but it may be lit in a different colour, or it may be a flashing light. The light indicator 235 used to indicate a drying cycle is taking place may be a different light indicator. At step S6 once the cleaning cycle and drying cycle if selected at step S41 is complete the wash station alerts the operator via the user interface 229 that cleaning is complete and the printhead may be removed. For example, the relevant light indicator(s) 235 may be lit continuously, or they may be flashing. In some embodiments, the wash station 201 may indicate to an operator that the cleaning and / or drying cycle is complete by playing a sound. The operator at step S7 can then proceed to move the cleaned printhead from the printhead receiving portion 211. At any time during the cleaning process the operator may press the stop button 233. If the stop button 233 is pressed the cleaning cycle will stop and the operator may remove the printhead 105 from the wash station. At all times during steps S3 to S6 the controller 251 may confirm one or more of the following: that a printhead 105 is present; and / or that the cleaning liquid supply container 241 is present; and / or that the cleaning liquid supply container 241 contains enough cleaning liquid for the cleaning cycle selected; and / or that the cleaning liquid supply container 241 contains an appropriate cleaning liquid for the printhead 105 received in the printhead receiving portion 211; and / or that a cleaning liquid collection container 263 is present; and / or that the cleaning liquid collection container 263 has adequate empty volume to receive the cleaning liquid used in the cleaning cycle. If one or more of the above are not satisfied the wash station may either not begin a cleaning cycle or may immediately stop the cleaning cycle. The wash station may be configured to indicate that the cleaning liquid collection container 263 requires emptying or replacing after a certain number of cleaning cycles has been performed, or after the wash station has performed cleaning for a predetermined amount of time. The wash station may be configured to indicate that the cleaning liquid supply bottle 241 requires emptying or replacing after a certain number of cleaning cycles has been performed, or after the wash station has performed cleaning for a predetermined amount of time. It will be appreciated that in some instances it may be desirable to clean the printhead receiving portion 211. As such the cleaning cycle may take place without a printhead 105 being present. It is preferable that during steps S3 to S6 when the printhead 105 is provided in the printhead receiving portion 211 that no ink is ejected from the printhead. However, in some instances, when the printhead 105 is inserted into the printhead receiving portion 211, the printhead 105 may continue to supply ink. This may reduce downtime of the printer and may mitigate against ink drying in regions of the printhead or umbilical which could result in blockages. In some embodiments, if the printhead 105 is still supplying ink when inserted into the wash station, the controller 251 may request that the printhead 105 stops supplying ink. In other embodiments, the controller 251 may be configured to instruct the printhead 105 to start supplying ink when the printhead 105 is received in the wash station. A sloped base 271 is provided above the base 205 of the external housing 203. The sloped base 271 is provided such that any cleaning liquid leaving the outlet opening 240 will fall onto the base 271. The sloped base 271 is sloped in a direction towards the second outlet opening 261, this promotes the flow of cleaning liquid to the second outlet opening 261. Providing a sloped base 271 mitigates against pooling of liquid in the wash station 201. In some embodiments the base 271 may be sized such that cleaning liquid can pool and be collected in the base 271 of the wash station. This may be advantageous if the collection container 263 is full or if a collection container 263 is not available. The base 271 may be sized to hold a volume that is equal to or greater than the volume of the cleaning liquid supply bottle 241. The base 205, including the sloped base 271 may be able to be removed from the wash station, the ability to remove and replace the base allows for cleaning of the base and for any liquid that accumulates in the base to be removed. Removal of the base also allows for the internal components of the wash station to be easily accessed for maintenance and / or cleaning. Figure 6 shows a schematic cross-sectional view of another wash station 301. For ease of understanding only the differences between the wash station 301 shown in Figure 6 and the wash station 201 shown in Figures 3 and 4 are described. Further, features of the wash station 301 that are the same as features of the wash station 201 are provided with the same reference signs. The wash station 301 differs from the wash station 201 in that it comprises a cleaning liquid supply channel 302. The cleaning liquid supply channel 302 is configured to receive a cleaning liquid from the printhead 105. In particular, the cleaning liquid may be a solvent from a solvent container that is located in the main body of the printer that the printhead 105 is connected to via the umbilical 107. The cleaning liquid supply channel 302 is configured to deliver cleaning liquid to the fluid supply nozzles 239. In the embodiment shown in Figure 6, the cleaning liquid supply channel 302 and a supply line from the cleaning liquid supply container 241 meet at a valve 304. The valve 304 is arranged to selectively control if cleaning liquid is delivered to the fluid supply nozzles 239 from the cleaning liquid supply line 302, from the cleaning liquid supply container 241, from both the cleaning liquid supply line 302 and the cleaning liquid supply container 241, or from none of cleaning liquid supply line 302 and the cleaning liquid supply container 241. The cleaning liquids may not be the same from either source. Providing cleaning liquid from the printer to clean the printhead 105 is advantageous as the printhead 105 can still be cleaned even if there is not an adequate amount of cleaning liquid in the cleaning liquid supply container 241, or if the cleaning liquid supply container 241 is not present. Although not shown in Figure 6, in some embodiments, the cleaning liquid supply line 302 may be configured to deliver the cleaning liquid from the printhead 105 directly into the cleaning liquid supply container 241. In this case the valve 304 may not be required. In other embodiments, the cleaning liquid supply container 241 may be absent, such that all cleaning liquid delivered to the fluid supply nozzles 239 is provided via the printhead 105. Additionally, the cleaning liquid supply container receiving portion 219 may also be absent. Providing cleaning liquid from the printer via the printhead 105 is advantageous as it mitigates against the need for the wash station to have its own cleaning liquid supply. Even if the wash station 201 has its own cleaning liquid supply container 241, it may still be advantageous to supply cleaning liquid from the printer. This is because the cleaning liquid from the printer may be different to and better for cleaning the printhead 105 than the cleaning liquid in the supply container 241. It is also advantageous for when there is not an adequate volume of cleaning liquid in the cleaning liquid supply container 241. Figure 7 shows a schematic cross-sectional view of another wash station 401. For ease of understanding only the differences between the wash station 401 shown in Figure 7 and the wash station 201 shown in Figures 3 and 4 will be described. Further, features of the wash station 401 that are the same as features of the wash station 201 are provided with the same reference signs. The wash station 401 differs from the wash station 201 in that it does not comprise a fan and it does not comprise a cleaning liquid supply container. Instead, the wash station 401 comprises a compressor 451. The compressor 451 is configured to delivered pressurised air to the fluid supply nozzles 239. The printhead 105 is cleaned by cleaning liquid that is delivered into the printhead receiving portion via the printhead 105 and originates from a source (e.g. a solvent container) in the main body of the printer that the printhead is connected to via the umbilical 107. As the cleaning liquid (labelled 453) is ejected through the nozzle of the printhead 105 pressurised air is delivered into the printhead receiving portion 211 by the fluid supply nozzles 239. The delivery of the pressurised air causes the cleaning fluid 453 to be disturbed and distributed about the printhead 105, which results in cleaning of the printhead 105. Once the supply of cleaning fluid 453 is stopped the fluid supply nozzles 239 may be used to assist with drying of the printhead 105. It will be appreciated that features of the wash station 201 may be combined with the wash stations 301,401. By way of example, the wash station 401 may be provided with a fan to assist with drying of the printhead 105. Similarly, the wash stations 201, 301 may be modified to additionally clean the printhead 105 in the manner of the wash station 401.

Claims

1. An electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the electrically powered wash station comprising:a printhead receiving portion for receiving the printhead to be cleaned;a fluid supply nozzle configured to receive a fluid from a fluid source and supply fluid into the printhead receiving portion to clean the printhead; andan energy storage device configured to store energy for providing electrical power to the wash station.

2. The electrically powered wash station according to claim 1, wherein the energy storage device comprises a battery.

3. The electrically powered wash station according to claim 1 or claim 2, wherein the energy storage device is configured to provide power to at least one of:a controller;a valve;a pump;a light source; and a fan.

4. The electrically powered wash station according to any preceding claim, wherein the wash station comprises an external housing and an internal housing;wherein the internal housing defines the printhead receiving portion, and the internal housing is at least partly received within the external housing.

5. The electrically powered wash station according to claim 4, wherein the internal housing comprises a first outlet opening, and the external housing comprises a second outlet opening; andwherein the first outlet opening is in fluid communication with the second outlet opening.

6. The electrically powered wash station according to claim 5, wherein the first outlet opening is offset from the second outlet opening.

7. The electrically powered wash station according to claim 5 or claim 6, further comprising a cleaning liquid collection container; andwherein the cleaning liquid collection container is in fluid communication with the second outlet opening.

8. The electrically powered wash station according to any of claims 5 to 7, wherein a valve is provided at the second outlet opening.

9. The electrically powered wash station according to claim 8, when dependent on claim 7, wherein the valve is configured to permit the flow of liquid through the second outlet opening when the cleaning liquid collection container is connected to the wash station.

10. The electrically powered wash station according to any preceding claim, wherein the fluid supply nozzle is configured to supply a cleaning liquid into the printhead receiving portion.

11. The electrically powered wash station according to claim 10, further comprising a cleaning liquid supply container which is configured to store cleaning liquid for cleaning the printhead, and wherein the cleaning liquid in the cleaning liquid supply container is the fluid source.

12. The electrically powered wash station according to any preceding claim, further comprising a cleaning liquid supply channel configured to receive cleaning liquid from the printhead; andwherein the cleaning liquid supply channel is configured to supply cleaning liquid to the fluid supply nozzle.

13. The electrically powered wash station according to any of claims 1 to 9, wherein the fluid supply nozzle is configured to supply a pressurised gas into the printhead receiving portion.

14. The electrically powered wash station according to any preceding claim, further comprising a plurality of fluid supply nozzles;wherein the printhead receiving portion defines a central axis; andwherein the plurality of fluid supply nozzles are configured to direct a fluid generally towards the central axis, and the plurality of fluid supply nozzles are spaced apart about the central axis.

15. The electrically powered wash station according to claim 14, wherein at least one of the plurality of fluid supply nozzles is configured to supply a cleaning liquid into the printhead receiving portion.

16. The electrically powered wash station according to claim 14 or claim 15, wherein at least one of the plurality of fluid supply nozzles is configured to supply a pressurised gas into the printhead receiving portion.

17. An electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the printhead comprising:a nozzle for ejecting droplets of ink;a charge electrode for selectively charging the droplets of ink ejected from the nozzle;a deflection electrode for deflecting the charged droplets of ink; anda gutter for collecting uncharged droplets of ink;the electrically powered wash station comprising:a printhead receiving portion for receiving the printhead to be cleaned;a cleaning liquid supply container configured to store cleaning liquid for cleaning the printhead;a fluid supply nozzle configured to receive cleaning liquid from the cleaning liquid supply container and to direct the cleaning liquid into the printhead receiving portion;an electrically powered pump configured to pump cleaning liquid from the cleaning liquid supply container to the fluid supply nozzle; anda battery configured to provide electrical power to at least the pump.

18. The electrically powered wash station according to claim 17, further comprising a fan configured to generate an airflow in the printhead receiving portion; and wherein the battery is configured to provide power to the fan.

19. The electrically powered wash station according to claim 17 or claim 18, further comprising a controller and a light source; andwherein the battery is configured to provide electrical power to the controller and the light source.

20. A method for operating an electrically powered wash station for cleaning a printhead of a continuous inkjet printer, the method comprising:storing a cleaning liquid in a cleaning liquid supply container of the electrically powered wash station;powering a pump using a battery;pumping the cleaning liquid from the cleaning liquid supply container to a fluid supply nozzle;supplying cleaning fluid via the fluid supply nozzle into a printhead receiving portion of the electrically powered wash station to clean the printhead.

21. The method of claim 20, further comprising:powering a fan using the battery and generating an airflow in the printhead receiving portion.

22. The method of claim 20 or claim 21, further comprising inserting a printhead of a continuous inkjet printer into the printhead receiving portion.39

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