Patent Publication Number: US-7901065-B2

Title: Printer incorporating a cutter module

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of U.S. patent application Ser. No. 10/760,230 filed on Jan. 21, 2004, now issued as U.S. Pat. No. 7,237,888-all of which are herein incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The invention pertains to printers and more particularly to a printer for wallpaper. The printer is particularly adapted to print long rolls of full color wallpaper and is well suited to serve as the basis of both retail and franchise operations which pertain to print-on-demand wallpaper. 
     CO-PENDING APPLICATIONS 
     Various methods, systems and apparatus relating to the present invention are disclosed in the following co-pending applications filed by the applicant or assignee of the present invention simultaneously with the present application: 
                                                7,156,508   7,159,972   7,083,271   7,165,834   7,080,894       7,201,469   7,090,336   7,156,489   10/760,233   10/760,246       7,083,257   10/760,243   10/760,201   7,219,980   10/760,253       10/760,255   10/760,209   7,118,192   10/760,194   10/760,238       7,077,505   7,198,354   7,077,504   10/760,189   7,198,355       10/760,232   10/760,231   7,152,959   7,213,906   7,178,901       10/760,227   7,108,353   7,104,629   10/760,254   10/760,210       10/760,202   7,201,468   10/760,198   10/760,249   10/760,263       10/760,196   10/760,247   7,156,511   10/760,264   10/760,244       7,097,291   10/760,222   10/760,248   7,083,273   10/760,192       10/760,203   10/760,204   10/760,205   10/760,206   10/760,267       10/760,270   7,198,352   10/760,271   10/760,275   7,201,470       7,121,655   10/760,184   10/760,195   10/760,186   10/760,261       7,083,272   10/760,180   7,111,935   10/760,213   10/760,219       10/760,237   10/760,221   10/760,220   7,002,664   10/760,252       10/760,265   7,168,654   7,201,272   6,991,098   7,217,051       6,944,970   10/760,215   7,108,434   10/760,257   7,210,407       7,186,042   10/760,266   6,920,704   7,217,049   10/760,214       10/760,260   7,147,102   10/760,269   10/760,199   10/760,241                    
The disclosures of these co-pending applications are incorporated herein by cross-reference.
 
     BACKGROUND OF THE INVENTION 
     The size of the wallpaper market in the United States, Japan and Europe offers strong opportunities for innovation and competition. The retail wall covering market in the United States in 1997 was USD $1.1 billion and the market in the United States is estimated at over US 1.5 billion today. The wholesale wallpaper market in Japan in 1999 was JPY $158.96 billion. The UK wall coverings market was £186 m in 2000 and is expected to grow to £197 m in 2004. 
     Wallpapers are a leading form of interior design product for home improvement and for commercial applications such as in offices, hotels and halls. About 70 million rolls of wallpaper are sold each year in the United States through thousands of retail and design stores. In Japan, around 280 million rolls of wallpaper are sold each year. 
     The wallpaper industry currently operates around an inventory based model where wallpaper is printed in centralized printing plants using large and expensive printing presses. Printed rolls are distributed to a point of sale where wallpaper designs are selected by consumers and purchased subject to availability. Inventory based sales are hindered by the size and content of the inventory. 
     The present invention seeks to transform the way wallpaper is currently manufactured, distributed and sold. The invention provides for convenient, low cost, high quality products coupled with a dramatically expanded range of designs and widths which may be offered by virtue of the present invention. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an alternative to existing wallpaper printing technology and business methods. 
     The invention seeks to enable immediate printing and delivery of wallpapers in retail or design stores to a customer&#39;s required roll length. 
     The invention also seeks to enable immediate access to an extensive portfolio of designs for customer sampling and sale. 
     The invention may provide photographic quality designs that are not possible using analogue printing techniques. 
     The invention also seeks to eliminate stock-out, stock-control/ordering and stock obsolesces issues. 
     It is an object of the invention to significantly reducing customer wastage by printing to any length (and a variety of widths) required by the customer rather that restricting purchases to fixed roll sizes. 
     The invention seeks to enable customization and innovation of wallpaper design for individuals or businesses. 
     In a first aspect the present invention provides a self contained printer for producing rolls of wallpaper, comprising a cabinet in which is located a media path which extends from a media cartridge loading area to a winding area; a full width digital color printhead located in the media path; a processor which accepts operator inputs which are used to configure the printer for producing a particular roll; and the winding area adapted to removably retain a core and wind onto it, wallpaper produced by the printer. 
     Preferably the self contained printer further comprises an internal dryer, the dryer located between the printhead and the winding area and adapted to blow hot air onto a printed media web. 
     Preferably the self contained printer, further comprises a cutting mechanism located between the printhead and the winding area and adapted to divide with a transverse cut, a media web in accordance with instructions provided by the processor. 
     Preferably the self contained printer further comprises a slitting mechanism located between the printhead and the winding area and adapted to longitudinally slit a media web in accordance with instructions provided by the processor. 
     Preferable the self contained printer further comprises a bar code scanner which communicates with the processor and through which operator preferences are input. 
     Preferably the self contained printer further comprises a well, external to the cabinet and adjacent to an exit slot; the well having at each end, spindles for aligning, retaining and removing a core, and for rotating the core according to instructions provided by the processor. 
     Preferably the self contained printer further comprises on a front exterior surface of the cabinet, a video display for displaying information about wallpaper that the printer may print. 
     Preferably the video display is a touch screen which can receive operator selections for use by the processor. 
     Preferably the media cartridge loading area further comprises a location for a media cartridge, in which a media cartridge dispensing slot is adjacent to the path. 
     Preferably the media cartridge loading area further comprises one or more locations where a media cartridge can be stored. 
     Preferably the printhead is mounted on a rail on which it slides into and out of a printing position across the path. 
     Preferably the printhead is a multi-color printhead which is supplied by separate ink reservoirs, the reservoirs connected to the printhead by a number of ink supply tubes, there being a tube disconnect coupling between the reservoirs and the printhead. 
     Preferably the contained printer further comprises an air supply and a tube for bringing a supply of air to the printhead which supply prevents media from sticking to the printhead. 
     Preferably the self contained printer further comprises a capper motor, the capper motor driving a capping device; the capping device sealing the printhead when not in use in order to prevent contamination from entering the printheads. 
     Preferably the capper device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printheads. 
     Preferably the self contained printer further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the path comprises a generally straight path. 
     Preferably the self contained printer further comprises a pre-heater platen located under the path and before the printhead. 
     Preferably the self contained printer further comprises a door which covers an opening into a lower compartment of the dryer; the door being moveable from a closed position which covers the opening, to an open position in which the media passes through the opening into the lower compartment and out of the compartment, also through the opening. 
     Preferably the slitting mechanism further comprises a pair of rotating end plates between which extend a number of transverse shafts, each shaft having one or more cutting disks, the end plates rotatable so that any shaft can be selected, or that no shaft be selected for cutting the media web. 
     In a second aspect the present invention provides a media cartridge, comprising a case in which a roll of blank media may be deployed; the case having two halves, hinged together, an area between the two halves, when closed, defining a media supply slot; and the case having internally and adjacent to the slot, a pair of rollers, at least one of the rollers being a driven roller which is supported at each end, by the case, for rotation by an external motor. 
     Preferably the two rollers are held in proximity by a resilient bias, one roller on either side of the slot. 
     Preferably the driven roller has at one end, a fixture for coupling to a driving shaft, the case having an opening which allows access to the fixture. 
     Preferably the rollers are held in proximity by a pair of clips; each roller having a circumferential slot at each end; each clip having two extensions which engage the slots of both rollers at one end. 
     Preferably the two extensions of a clip are joined to a clip body, the body having a central opening for receiving and locating a core which fits in the case. 
     Preferably the clip body has an anti-rotation feature which is adapted to engage with a cooperating feature of a core, to prevent the core from rotating in the case. 
     Preferably the media cartridge further comprises a core, adapted to cooperate with the clip body by engaging with the anti-rotation feature. 
     Preferably the case has at one or both ends, slots for receiving and retaining a clip body. 
     Preferably the media cartridge further comprises an integral handle at one end of the case. 
     Preferably the media cartridge further comprises a folding handle located on a top surface of the case. 
     Preferably the media cartridge further comprising an integral handle at one end of the case and a folding handle located on a top surface of the case. 
     Preferably the case is a molded polymeric case with an integral hinge, held in a closed position by one or more clips. 
     Preferably the driven roller is longer than the other roller, the other roller being an idler roller which is contained within the case when it is closed. 
     Preferably the clips are reversible and adapted to be used at either end of the case. 
     Preferably the two case halves are formed as a single molding with an integral hinge, the molding having formed in it internal slots for receiving a pair of clips which are used to hold the rollers in proximity. 
     Preferably one case half has formed in it a journal at each end for supporting one of the rollers. 
     Preferably one case half has formed in it a journal at each end for supporting the driven roller. 
     Preferably the media cartridge further comprises a core which is located in the case, the core having around it, a supply of blank wallpaper media. 
     In a third aspect the present invention provides a consumer tote for a roll of wallpaper, the tote comprising a disposable exterior in which is formed a main access flap and a pair of core access openings; and the tote having an interior in which is located a disposable core which is aligned with the access openings. 
     Preferably there is formed a gap between the access flap and an adjacent edge of the exterior, when the flap is closed. 
     Preferably the exterior is formed from a non-metallic textile. 
     Preferably the core is supported at each end by a molding having a hub which engages the core. 
     Preferably each hub surrounded by a bearing surface which locates the hub in a respective access opening. 
     Preferably the bearing surface makes contact with an inside bottom surface of the disposable exterior when the hub is located in the openings. 
     Preferably the bearing surface is circular and connected to the hub by spokes. 
     Preferably at least one hub has an external coupling for engaging a rotating winding spindle. 
     Preferably the coupling comprises a ring of teeth. 
     Preferably the consumer tote further comprises a handle which folds flat against the exterior. 
     Preferably the handle is formed by two similar sub-units which fold from a flat position to a cooperating position in which a handle opening in each sub-unit align to form a grip. 
     Preferably there is formed a gap between the access flap and an adjacent edge of the exterior, when the flap is closed; and each sub-unit has an edge which is affixed to the exterior, adjacent to the gap; the sub-units arranged in a mirror image relationship about the gap. 
     Preferably the consumer tote further comprises one of the access openings exposes a coupling formed on a hub which carries the core; and a visible marker is located on the exterior for indicating the location of the coupling. 
     Preferably the exterior is dimensioned to fit between the loading spindles of a wallpaper printing machine. 
     Preferably the exterior further comprises a viewing window. 
     Preferably the exterior is adapted to hold about 50 meters of wallpaper wound onto a core. 
     Preferably the adjacent edge includes a return lip. 
     Preferably the core is supported at each end by a molding having a hub which engages the core. 
     Preferably each hub surrounded by a bearing surface which locates the hub in a respective access opening. 
     In a fourth aspect the present invention provides a transverse cutter for a printer such as a wallpaper printer, comprising a chassis having end plates; the end plates being separated to allow a web of media to pass between them; the end plates supporting between them a cutting blade; and the blade supported at each end to perform a cutting motion which begins on one side of the web and finishes on an opposite side of the web. 
     Preferably one end plate supports a motor which is coupled to the blade. 
     Preferably the blade has a driven end that is carried eccentrically by a rotating member. 
     Preferably both ends of the blade are carried eccentrically by a rotating member. 
     Preferably the end plates have extending between them a pair of entry rollers in proximity, at least one of the entry rollers being powered. 
     Preferably the end plates have extending between them a pair of exit rollers in proximity, at least one of the exit rollers being powered. 
     Preferably the end plates have extending between them a pair of exit rollers in proximity, at least one of the exit rollers being powered; one each of the entry and exit rollers powered by a single motor carried by the chassis. 
     Preferably the one each of the entry and exit rollers are powered by a belt which passes around the one each of the entry and exit rollers and a rotating shaft associated with the motor. 
     Preferably the belt is external to an end plate which carries it. 
     Preferably the transverse cutter further comprises a slitting mechanism, the slitting mechanism further comprising one or more slitting shafts extending between the end plates, each shaft having one or more slitting disks arranged along its length, each disk having a cutting edge, the slitting mechanism selectively engageable to either enter or not enter a path followed by the web according to a requirement of an operator. 
     Preferably the slitting mechanism further comprises a pair of rotating end brackets between which extend the one or more slitting shafts, at least one of the brackets rotated by a motor carried by an end plate. 
     Preferably there are two or more slitting shafts arranged around a central support shaft all of which are carried by the brackets. 
     Preferably the transverse cutter further comprises a guide roller which extends between the end plates and under the path of the media; the guide roller having a number of circumferential grooves, one groove corresponding to the location of each cutting disk associated with the slitting mechanism. 
     Preferably the transverse cutter further comprises a guide roller which extends between the end plates and under the path of the media; the guide roller having a number of circumferential grooves, one groove corresponding to the location of each cutting disk associated with the slitting mechanism; each slitting shaft having an arrangement of cutting disks on it and each shaft is positionable such that each cutting disk carried by a selected shaft enters a corresponding groove of the guide roller when the selected shaft is rotated into a cutting position. 
     Preferably each slitting shaft has a different arrangement of cutting disks on it. 
     Preferably the cutting motion is initiated by a signal from a processor in a self contained wallpaper printer in which the cutter is located, the operation of the cutter determining a length of wallpaper, the length being determined by an input provided by an operator of the printer. 
     Preferably the slitting mechanism is selectively engageable by a signal from a processor in a self contained wallpaper printer in which the cutter is located, the operation of the slitting mechanism determining a width or widths of wallpaper, the width or widths being determined by an input provided by an operator of the printer. 
     In a fifth aspect the present invention provides a slitting mechanism for a printer such as a wallpaper printer, the slitting mechanism comprising a chassis having end plates; the end plates being separated by a transverse portion of the chassis to allow a web of media to pass between them; one or more rotating slitting shafts extending between the end plates, each shaft having one or more slitters arranged along its length, each slitter having a cutting edge; and the slitting mechanism selectively engageable to either enter or not enter a path followed by the web according to an input provided by an operator of the printer. 
     Preferably the slitting mechanism further comprises a pair of rotating end brackets between which extend the one or more slitting shafts, at least one of the brackets rotated by a motor carried by an end plate. 
     Preferably there are two or more slitting shafts arranged around a central support shaft all of which are carried between and by the brackets. 
     Preferably the slitting mechanism further comprises a guide roller which extends between the end plates and under the path of the media; the guide roller having a number of circumferential grooves, one groove corresponding to the location of each cutting disk associated with the slitting mechanism. 
     Preferably the slitting mechanism further comprises a guide roller which extends between the end plates and under the path of the media; the guide roller having a number of circumferential grooves, one groove corresponding to the location of each cutting disk associated with the slitting mechanism; each slitting shaft having an arrangement of cutting disks on it and each shaft is positionable such that each cutting disk carried by a selected shaft enters a corresponding groove of the guide roller when the selected shaft is rotated into a cutting position. 
     Preferably each slitting shaft has a different arrangement of cutting disks on it. 
     Preferably the slitting mechanism rotates into a selected position in response to a signal from a processor in a self contained wallpaper printer in which the mechanism is located, the position of the slitting mechanism determining a width or widths of wallpaper, based on a discrete number of width options provided to the operator, an operator&#39;s selection being determined by the processor from an input provided by the operator to the printer. 
     Preferably the slitting mechanism further comprises a transverse cutter extending between the end plates; the blade supported at each end to perform a cutting motion which begins on one side of the web and finished on an opposite side of the web. 
     Preferably one end plate supports a motor which is coupled to the blade. 
     Preferably the blade has a driven end that is carried eccentrically by a rotating member. 
     Preferably each end of the blade is carried eccentrically by a rotating member. 
     Preferably the end plates have extending between them a pair of entry rollers in proximity, at least one of the entry rollers being powered. 
     Preferably the end plates have extending between them a pair of exit rollers in proximity, at least one of the exit rollers being powered. 
     Preferably the end plates have extending between them a pair of exit rollers in proximity, at least one of the exit rollers being powered; one each of the entry and exit rollers powered by a single motor carried by the chassis. 
     Preferably the one each of the entry and exit rollers are powered by a belt which passes around the one each of the entry and exit rollers and a rotating shaft associated with the motor. 
     Preferably the belt is external to an end plate which carries it. 
     Preferably the cutting motion is initiated by a signal from a processor in a self contained wallpaper printer in which the cutter is located, the operation of the cutter determining a length of wallpaper, the length being determined by an input provided by an operator of the printer. 
     Preferably the input is provided through a touch screen video display located on the printer. 
     In a sixth aspect the present invention provides a dryer for a printer such as a wallpaper printer, the dryer comprising a compartment with a top opening for receiving a media web fed from the printer; a source of heated air located above the top opening for blowing heated air into the opening to dry printing on the media web. 
     Preferably the door covers the entire opening and acts to support the web when the door is closed. 
     Preferably the door pivots along an axis transverse to the path to reveal the opening. 
     Preferably the door is operated by a motor that operates a spool; the spool winding and releasing a cord which operates the door. 
     Preferably the dryer further comprises a preheater in the path but located before the opening. 
     Preferably the preheater is in the same plane as the door. 
     Preferably the source of heated air comprises a blower which feeds a stream of air into a plenum. 
     Preferably the dryer further comprises a temperature sensor in the plenum. 
     Preferably the compartment is adapted to receive the web as a suspended partial loop. 
     Preferably the compartment has an air vent which supplies a recirculation duct. 
     Preferably the recirculation duct extends from the compartment to an intake of an air supply that feeds the compartment. 
     Preferably the recirculation duct is a tube which extends upwardly from the compartment and includes an exhaust vent at an upper extremity. 
     Preferably the source of heated air further comprises a second blower which feeds a stream of air into the plenum. 
     Preferably the plenum has a heating element within it. 
     Preferably the compartment has two vents, each one supplying vented air to a separate recirculation duct, the ducts located on opposite sides of the compartment, each duct supplying recirculated air to a source of heated air. 
     Preferably the source of heated air is a pair of blowers which direct air into a plenum. 
     Preferably the blowers are located above the plenum. 
     Preferably the dryer is located within an on-demand wallpaper printer and is controlled by a processor within the printer. 
     In a seventh aspect the present invention provides a printer for producing rolls of wallpaper, comprising a cabinet in which is located a media path which extends from a media loading area to a winding area; a printhead located in the media path; a processor which accepts operator inputs from one or more input devices which are used to configure the printer for producing a particular roll; and the winding area adapted to removably retain a core and wind onto it, wallpaper produced by the printer wherein, the length and design of the roll are determined by the operator inputs. 
     Preferably the printer further comprises an internal dryer, the dryer located between the printhead and the winding area and adapted to blow hot air onto a printed media web. 
     Preferably the printer further comprises a cutting mechanism located between the printhead and the winding area and adapted to divide with a transverse cut, a media web in accordance with instructions provided by the processor. 
     Preferably the printer further comprises an input device for capturing data relating to a print job; the data being transmitted by the device to the processor; the processor using the data to establish a configuration for the printer. 
     Preferably the input device is a bar code scanner. 
     Preferably the printer further comprises on a front exterior surface of the cabinet, a video display for displaying information about wallpaper that the printer may print, including images of an operator selected pattern. 
     Preferably the video display is a touch screen which can receive operator selections for use by the processor. 
     Preferably the printhead is mounted on a rail on which it slides into and out of a printing position across the path. 
     Preferably the printhead is a page width inkjet style multi-color printhead which is supplied by separate ink reservoirs, the reservoirs connected to the printhead by a number of ink supply tubes, there being a tube disconnect coupling between the reservoirs and the printhead. 
     Preferably the printer further comprises an air supply and a tube for bringing a supply of air to the printhead which supply prevents media from sticking to the printhead. 
     Preferably the printer further comprises a capper motor, the capper motor driving a capping device; the capping device sealing the printhead when not in use in order to prevent contamination from entering the printheads. 
     Preferably the printer further comprises the capper device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printheads. 
     Preferably the printer further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the path comprises a generally straight path. 
     Preferably the printer further comprises a media supply canister, one or more of which may be inserted into and removed from the loading area, a canister containing a roll of blank wallpaper media. 
     Preferably the printer further comprises a door which covers an opening into a lower compartment of the dryer; the door being moveable from a closed position which covers the opening, to an open position in which the media passes through the opening into the lower compartment and out of the compartment, also through the opening. 
     Preferably the printer further comprises a slitting mechanism having a pair of rotating end plates between which extend a number of transverse shafts, each shaft having one or more cutters, the end plates rotatable so that any shaft can be selected, or that no shaft be selected for slitting the media web. 
     Preferably the printer further comprises the slitting mechanism is located between the printhead and the winding area and adapted to longitudinally slit a media web in accordance with instructions provided by the processor. 
     Preferably the printer further comprises a well, external to the cabinet and adjacent to an exit slot; the well having at each end, spindles for aligning, retaining and removing a core, and for rotating the core according to instructions provided by the processor. 
     Preferably the printer further comprises a pre-heater platen located under the path and before the printhead. 
     In an eighth aspect of the present invention there is provided a method for printing wallpaper onto a web of media, comprising the steps of utilizing an on-demand printer comprising a cabinet in which is located a media path which extends from a media loading area to a winding area, there being a printhead located in the media path, a processor which accepts operator inputs from one or more input devices; using one or more input devices which communicate with the processor to capture data from an operator regarding a specification for an operator&#39;s requirements; using the processor to operatively control the printer according to the data; and printing a single roll of wallpaper, on demand, according to a selected pattern. 
     Preferably the method further comprises representing the pattern as a symbol which can be captured as the data by an input device which communicates with the processor. 
     Preferably the method further comprises storing to a storage device accessible to the processor and internal to the cabinet, a plurality of selectable files for describing patterns for printing onto the media. 
     Preferably the method further comprises providing the printer with a video display for depicting the selected pattern. 
     Preferably the method further comprises using the video display as a touch screen input device to capture operator preferences. 
     Preferably the method further comprises providing the printer with a scanner for capturing data that specifies a selected pattern. 
     Preferably the method further comprises using the video display to display information that relates to the configuration. 
     Preferably printing a roll of wallpaper according to a selected pattern and the configuration further comprises inserting a blank core into a winding area, in or on the printer and accessible to an operator; winding the web onto the core after the web has been printed on; and severing the wound core from the web. 
     Preferably winding the web is performed by winding a length of a printed web onto the core; the length being determined in advance; the length being part of the configuration of the printer. 
     Preferably the core is contained in a tote during the winding. 
     Preferably winding the web is further performed by slitting the web, within the printer, to one or more specified widths prior to winding; the one or more specified widths being a part of the printer configuration, having been communicated through one of the input devices. 
     Preferably the method further comprises providing one or more collections of patterns; each pattern in a collection having a symbol which can be used as an operator input. 
     Preferably the specification for an operator&#39;s requirements comprises a pattern and the configuration; the configuration being one or more parameters selected from the group comprising: roll length, a roll slitting arrangement, one or more modifications to the pattern, or a selection of media to be printed on. 
     Preferably utilizing an on-demand printer further comprises loading a media cartridge into the printer, the cartridge containing a unprinted web of media; and using a motor in the printer to advance the unprinted web into the path; automatically threading the media from the loading area, to the winding area. 
     Preferably utilizing an on-demand printer further comprises loading a media tote into the winding area; winding a printed roll of wallpaper onto a core inside the tote; and severing the printed roll on the core from the web. 
     Preferably utilizing an on-demand printer further comprises loading an empty core into the winding area; winding a printed roll of wallpaper onto a core; and severing the printed roll on the core from the web using an automated cutting mechanism inside the printer, the cutting mechanism receiving a signal for commencing cutting from the processor. 
     Preferably printing a roll of wallpaper according to a selected pattern further comprises using a full width, stationary color printhead to print onto the web while it is in motion along the path. 
     Preferably the method further comprises drying the web after it is printed on but before it is dispensed by the printer. 
     Preferably the method further comprises admitting the printed web into a compartment in an internal dryer and exposing the web to a stream of heated air. 
     Preferably the method further comprises heating the web with a pre-heater platen located under the path before the web passes the printhead. 
     In a ninth aspect the present invention provides a method for operating a wallpaper printing business, comprising the steps of: utilizing an on-demand printer comprising a cabinet in which is located a media path which extends from a media loading area to a printhead and from the printhead to a dispensing slot; using one or more printer input devices which communicate with a processor to capture data regarding one or more customer&#39;s requirements; the data comprising at least a customer selected pattern; printing a roll of wallpaper, onto a web of blank media, on demand, according to the selected pattern; and charging a customer for the roll. 
     Preferably the method further comprises allowing the customer to select a width; 
     capturing the width as data with a printer input device; and using the printer to slit the web to the width. 
     Preferably the method further comprises allowing the customer to select a roll length; 
     capturing the roll length as data with a printer input device; and using the printer to cut the web to the roll length. 
     Preferably the method further comprises charging the customer only for the length. 
     Preferably the method further comprises acquiring data from a touch screen display which is also adapted to display the pattern. 
     Preferably the method further comprises providing the printer with a scanner for capturing data that specifies a selected pattern or other data. 
     Preferably the method further comprises allowing the customer to select a media type and using that media type in the printer. 
     Preferably the customer selected pattern is selected by the customer from a collection of swatches which correspond to patterns that the printer is able to print on demand. 
     Preferably the customer can use an input device to alter how the printer prints a selected pattern. 
     Preferably the method further comprises providing a collection of swatches; 
     assigning a symbol to each swatch; using the symbol as an input by using a printer input device. 
     Preferably the method further comprises the customer&#39;s requirements comprise a pattern and a configuration; the configuration being one or more parameters selected from the group comprising: roll length, a roll slitting arrangement, one or more modifications to the pattern, or a selection of media to be printed on. 
     Preferably utilizing an on-demand printer further comprises loading a media canister into the printer, the canister containing an unprinted web of media; and using a motor in the printer to advance the unprinted web into the path; automatically threading the media from the loading area, to the dispensing slot. 
     Preferably utilizing an on-demand printer further comprises loading a disposable media tote into a winding area adjacent to the dispensing slot; winding a printed roll of wallpaper onto a core inside the tote; and severing the printed roll on the core from the web. 
     Preferably utilizing an on-demand printer further comprises severing the printed roll on the core from the web using an automated cutting mechanism inside the printer, the cutting mechanism receiving a signal for commencing cutting from the processor. 
     Preferably printing a roll of wallpaper according to a selected pattern further comprises using a full width, color printhead to print onto the web while it is in motion along the path. 
     Preferably the method further comprises drying the web after it is printed on but before it is dispensed by the printer. 
     Preferably an operator uses the printer for a customer. 
     Preferably the method further comprises allowing a customer to design a custom pattern defined by data; using the one or more input devices to capture the data; and printing the custom pattern on demand. 
     Preferably the method further comprises selling printed rolls as they are produced to eliminate printed wallpaper inventory. 
     In a tenth aspect the present invention provides a method for operating a wallpaper printing franchise, comprising the steps of providing to franchisees, an on-demand printer comprising a cabinet in which is located a media path which extends from a media loading area to a printhead and from the printhead to a dispensing slot; the printer having one or more printer input devices which communicate with a processor to capture data regarding one or more customer requirements, the data comprising at least a customer selected pattern; providing the franchisee with a collection of patterns in a digital storage medium that can be read by the printer; enabling the franchisee to print a roll of wallpaper, onto a web of blank media, on demand, according to the selected pattern; and obtaining or attempting to obtain a fee from the franchisee. 
     Preferably the printer allows the customer to select a width; the printer captures the width as data with a printer input device; and the printer is used to slit the web to the width. 
     Preferably the printer allows the customer to select a roll length; the printer captures the roll length as data with a printer input device; and the printer is used to cut the web to the roll length. 
     Preferably the franchisee charges the customer only for the length. 
     Preferably the printer acquires data from a touch screen display which is also adapted to display the pattern to a customer of the franchisee. 
     Preferably the printer is provided with a scanner for capturing data that specifies a customer selected pattern or other data. 
     Preferably the method further comprises providing the franchisee with a variety of blank media types so that the franchisee may use any one of them in the printer. 
     Preferably the franchisee is provided with one or more collections of printed swatches which correspond to patterns that the printer is able to print on demand. 
     Preferably a customer of the franchisee can use an input device to alter how the printer prints a selected pattern. 
     Preferably each swatch is assigned a printed symbol; and the franchisee uses the symbol as an input by using a printer input device. 
     Preferably the customer&#39;s requirements comprise a pattern and a configuration; 
     the configuration being one or more parameters selected from the group comprising: roll length, a roll slitting arrangement, one or more modifications to the pattern, or a selection of media to be printed on. 
     Preferably enabling the franchisee to print further comprises providing the franchisee with a plurality of media canisters adapted to contain an unprinted web of media. 
     Preferably the method further comprises providing a motor in the printer to advance the unprinted web into the path by automatically threading the media through the printer. 
     Preferably the method further comprises loading the canister with blank media before providing it to the franchisee. 
     Preferably the franchisee is provided, from time to time, with new patterns for customers to select. 
     Preferably utilizing an on-demand printer further comprises loading a disposable media tote into a winding area adjacent to the dispensing slot; winding a printed roll of wallpaper onto a core inside the tote; and severing the printed roll on the core from the web. 
     Preferably the printhead is a full width color printhead that prints patterns accessible to the processor. 
     Preferably printing a roll of wallpaper according to a selected pattern further comprises using a full width, color printhead to print onto the web while it is in motion along the path. 
     Preferably the method further comprises drying the web after it is printed on but before it is dispensed by the printer. 
     Preferably the franchisee is instructed to operate the printer for a customer. 
     Preferably the franchisee is provided with totes for holding cores which cooperate with a winding area of the printer at which area are located one or more spindles that support the core during winding. 
     Preferably the method further comprises enabling the franchisee to sell printed rolls as they are produced to eliminate printed wallpaper inventory. 
     In an eleventh aspect the present invention provides a printer for producing rolls of wallpaper, comprising a frame in which is located a media path which extends from a media loading area to a winding area; a printhead located across the media path;
     one or more input devices for capturing operator instructions; a processor which accepts operator inputs which are used to configure the printer for producing a particular roll; and   the winding area adapted to removably retain a core and wind onto it, wallpaper produced by the printer.   

     Preferably the printer further comprises an internal dryer, the dryer located between the printhead and the winding area and adapted to blow air onto a printed media web. 
     Preferably the printer further comprises a cutting mechanism located between the printhead and the winding area and adapted to divide a media web from a wound portion. 
     Preferably the printer further comprises a slitting mechanism located between the printhead and the winding area and adapted to longitudinally slit a media web prior to winding. 
     Preferably the printer further comprises a bar code scanner which communicates with the processor and through which data is input. 
     Preferably the printer further comprises a well, external to the cabinet and adjacent to an exit slot; the well having at each end, spindles for aligning, retaining and removing a core, and for rotating the core. 
     Preferably the printer further comprises on a front exterior surface of the cabinet, a tilting video display for displaying information about wallpaper that the printer may print. 
     Preferably the video display is a touch screen which can receive operator selections for use by the processor. 
     Preferably the loading area further comprises a location for a media cartridge, in which a media cartridge dispensing slot is adjacent to the path. 
     Preferably the media cartridge loading area further comprises one or more locations where a media cartridge can be stored. 
     Preferably the printhead is a full width color inkjet type printhead, mounted on a rail on which it slides into and out of a printing position across the path. 
     Preferably the printhead is a multi-color printhead which is supplied by separate ink reservoirs, the reservoirs connected to the printhead by a number of ink supply tubes, there being a tube disconnect coupling between the reservoirs and the printhead. 
     Preferably the printer further comprises an air supply and a tube for bringing a supply of air to the printhead which supply prevents media from contacting the printhead. 
     Preferably the printer further comprises a capper motor, the capper motor driving a capping and blotting device; the capping device sealing the printhead when not in use in order to prevent contamination from entering the printheads. 
     Preferably the capping and blotting device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printheads. 
     Preferably the printer further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the path comprises a generally straight path which is self threading. 
     Preferably the printer further comprises a pre-heater platen located before the printhead. 
     Preferably the printer further comprises a door which covers an opening into a lower compartment of the dryer; the door being moveable from a closed position which covers the opening, to an open position in which the media passes through the opening into the lower compartment and out of the compartment, also through the opening. 
     Preferably the slitting mechanism further comprises a pair of rotating brackets between which extend a number of transverse shafts, each shaft having one or more cutters, the end brackets rotatable so that any shaft can be selected, or that no shaft be selected for cutting the media web. 
     In a twelfth aspect the present invention provides a method for printing wallpaper onto a web of media, comprising the steps of utilizing an on-demand printer comprising a cabinet in which is located a media path, there being a full width printhead located across the media path, there being a processor which accepts operator inputs from one or more input devices and which controls the printer; using one or more input devices which communicate with the processor to capture data from an operator regarding a specification; running the printer according to the data; printing a single roll of wallpaper, on demand, according to a selected pattern and configuration; changing the pattern according to a new datum from an operator; and then printing a new roll onto the same web. 
     Preferably the method further comprises representing the pattern and the new pattern as symbols which can be captured as the data by an input device which communicates with the processor. 
     Preferably the method further comprises storing to a storage device accessible to the processor and internal to the cabinet, a plurality of selectable files for describing the patterns for printing onto the media. 
     Preferably the method further comprises providing the printer with a video display for depicting the selected pattern. 
     Preferably the method further comprises using the video display as a touch screen input device to capture operator preferences. 
     Preferably the method further comprises providing the printer with a scanner for capturing symbols that specify a selected pattern. 
     Preferably the method further comprises using the video display to display information that relates to a roll. 
     Preferably printing a roll of wallpaper according to a selected pattern and the configuration further comprises inserting a blank core into a winding area, in or on the printer and accessible to an operator; affixing the web to the core; winding the web onto the core after the web has been printed on; and severing the wound core from the web. 
     Preferably winding the web is performed by winding a length of a printed web onto the core; the length being determined in advance; the length being specified by the data. 
     Preferably the core is contained in a closed tote during the winding. 
     Preferably winding the web is further performed by slitting the web, within the printer, to one or more specified widths prior to winding; the one or more specified widths being specified by data, having been communicated through one of the input devices. 
     Preferably the method further comprises providing one or more swatches of patterns; 
     each swatch in a collection having a symbol which can be used as an operator input. 
     Preferably the specification for an operator&#39;s requirements comprises a pattern and the configuration; the configuration being one or more parameters selected from the group comprising: roll length, a roll slitting arrangement, one or more modifications to the pattern, or a selection of media to be printed on. 
     Preferably utilizing an on-demand printer further comprises loading a re-usable media cartridge into the printer, the cartridge containing a unprinted web of media; and 
     using a motor in the printer to drive a roller in the cartridge to advance the unprinted web into the path; automatically threading the media from the loading area, to the winding area. 
     Preferably utilizing an on-demand printer further comprises loading a media tote into the winding area; winding a printed roll of wallpaper onto a core inside the tote when it is closed; and severing the printed roll on the core from the web. 
     Preferably utilizing an on-demand printer further comprises loading an empty core into the winding area; winding a printed roll of wallpaper onto a core; and severing the printed roll on the core from the web using an automated cutting mechanism inside the printer, the cutting mechanism receiving a signal for commencing cutting from the processor. 
     Preferably printing a roll of wallpaper according to a selected pattern further comprises: 
     using a full width, stationary color inkjet type printhead to print onto the web while it is in motion along the path. 
     Preferably the method further comprises drying the web with hot air after it is printed on but before it is dispensed by the printer. 
     Preferably the method further comprises admitting the printed web as a hanging loop into a compartment in an internal dryer and exposing the web to a stream of heated air. 
     Preferably the method further comprises heating the web with a pre-heater platen located under the path before the web passes the printhead. 
     In a thirteenth aspect the present invention provides a method for drying a moving web of media in a printer such as a wallpaper printer, the method comprising the steps of loading the web in a path that traverses a compartment in a dryer within the printer, the compartment having an opening across the top; allowing the moving web to descend into the compartment, as required; and blowing heated air from above the opening. 
     Preferably a door covers the opening and acts to support the web when the door is closed. 
     Preferably the method further comprises opening the door along an axis transverse to the path to reveal the opening. 
     Preferably the method further comprises operating the door with a motor that operates a spool; the spool winding and releasing a cord which operates the door. 
     Preferably the method further comprises heating the web with a preheater in the path and located before the opening. 
     Preferably the preheater is in the same plane as the door. 
     Preferably the source of heated air comprises a blower which feeds a stream of air into a plenum in which is located a heating element. 
     Preferably the method further comprises using a temperature sensor in the plenum to control the flow of heated air. 
     Preferably the compartment is adapted to receive the web as a suspended partial loop. 
     Preferably the method further comprises recirculating air from the compartment through a recirculation duct. 
     Preferably the method further comprises recirculating air from the compartment to an intake of an air supply that feeds the compartment. 
     Preferably the method further comprises exhausting air from the recirculation duct through a tube which extends upwardly from the compartment and includes an exhaust vent at an upper extremity. 
     Preferably the method further comprises using a second blower which feeds a stream of air into the plenum. 
     Preferably the plenum has external recirculation ducts for the compartment at either end. 
     Preferably the compartment has two vents, each one supplying vented air to a separate recirculation duct, the ducts located on opposite sides of the compartment, each duct supplying recirculated air to a source of heated air and each one having an exhaust opening at an upper extremity. 
     Preferably the source of heated air is a pair of blowers which can receive recirculated air from the compartment. 
     Preferably the blowers are located above the plenum. 
     Preferably the dryer is located within an on-demand wallpaper printer and is controlled by a processor which controls the printer. 
     In a fourteenth aspect the present invention provides a method of supplying a media web to a wallpaper printer, comprising the steps of opening a reusable case; placing into the case a core onto which has been located a supply roll of blank wallpaper media; 
     supporting the core for rotation within the case; leading a free edge of the roll between a pair of rollers and past an edge of the open case; then with the rollers located within the case and on either side of the web, closing the case and loading it into a printer. 
     Preferably the method further comprises introducing the two rollers into a pair of resilient bias devices that holds the rollers in proximity. 
     Preferably the method further comprises locating an opening of each resilient bias device around the core before closing the case. 
     Preferably one roller is a driven roller having at one end a coupling, and locating the coupling in an opening of the case which allows an external spindle to access the coupling when the case is closed. 
     Preferably each roller has a circumferential slot at each end; each bias device having two extensions which engage the slots of both rollers at one end. 
     Preferably the two extensions of each bias device are joined to a flat clip body, the body having a central opening for receiving and locating the core. 
     Preferably each body has an anti-rotation feature which is adapted to engage with a cooperating feature located at each end of the core, so to prevent the core from rotating in the case; and further comprising the step of engaging the anti-rotation feature with the cooperating feature before the case is closed. 
     Preferably the case has at one or both ends, slots for receiving the bodies, and further comprising the step of: locating one or both bodies in a respective slot before the case is closed. 
     Preferably the method further comprises lifting the case by an integral handle formed at one end of the case. 
     Preferably the method further comprises using a folding handle located on a top surface of the case. 
     Preferably the case has two halves which are hinged together and define when closed, a slot which extends between the halves through which the free edge of the roll exits the case. 
     Preferably the method further comprises using resilient clips which engage the case halves and hold them in a closed position. 
     Preferably the rollers are brought into proximity and biased against one another before the case is closed. 
     Preferably both rollers are located with respect to the core before the case is closed. 
     Preferably the case is formed from two case halves manufactured from a single molding with an integral hinge. 
     Preferably the rollers are both removable and one case half has formed in it a journal in which a roller is supported before the case is closed. 
     Preferably the method further comprises re-using the case by opening it, removing the core and the rollers, introducing a new core with a new roll around it; and leading a free edge of the new roll between a pair of rollers and past an edge of the open case; then closing the case with the rollers located in it and loading it again into a printer. 
     Preferably the roll and the new roll are of different blank media types. 
     Preferably the printer is self threading. 
     In a fifteenth aspect the present invention provides a printhead assembly for a printer which prints onto a moving web that follows a path, comprising:
     a full width printhead located across the path;   the printhead comprising a color printhead which is at least as wide as the web;   the printhead being supplied with a number of different inks which are remote from the printhead and which supply the printhead through tubes.   

     Preferably the printhead assembly further comprises a rail which is located across the path and along which the printhead slides into and out of a printing position. 
     Preferably the printhead is secured to the rail by fasteners which allow the printhead to be removed when the fasteners are disengaged. 
     Preferably the inks are contained in individual reservoirs and a supply tube connects each reservoir to the printhead. 
     Preferably the printhead assembly further comprises an air supply which supplies a stream of air, through a supply tube, to a location near the printhead from where the stream impinges onto the web to prevent it from adhering to the printhead. 
     Preferably the printhead assembly further comprises a capping device having a capper motor for sealing the printhead when not in use in order to prevent contamination from entering the printheads. 
     Preferably the capping device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printhead. 
     Preferably the printhead assembly further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the printhead assembly further comprises a coupling in each ink supply tube which can be disconnected so that the printhead can be withdrawn. 
     Preferably the printhead assembly further comprises a coupling in the air supply tube which can be disconnected so that the printhead can be withdrawn. 
     Preferably the printhead assembly further comprises a pre-heater located adjacent to the path and before the printhead. 
     Preferably the printhead assembly further comprises a dryer in the same path as the printer the dryer adapted to dry the ink deposited by the printer. 
     Preferably the dryer has a compartment located beneath an opening; the opening being essentially in the path; there being a source of heated air located above the opening, the source of heated air adapted to blow heated air into the opening. 
     Preferably the opening is coverable by a door; and the door covers the entire opening and acts to support the web when the door is closed. 
     Preferably the door pivots along an axis transverse to the path to reveal the opening. 
     Preferably the door is operated by a motor that operates a spool; the spool winding and releasing a cord which operates the door. 
     Preferably the source of heated air comprises a blower which feeds a stream of air into a plenum. 
     Preferably a temperature sensor is located in the plenum. 
     Preferably the compartment is adapted to receive the web in a catenary path. 
     Preferably the compartment has an air vent which supplies a recirculation duct that leads to a motor intake. 
     In a sixteenth aspect the present invention provides a printer for producing rolls of wallpaper, comprising a housing in which is located a media path which extends from a blank media intake to a wallpaper exit slot; a multi-color roll width removable printhead located in the housing and across the media path; the printhead being supplied by separate ink reservoirs, the reservoirs connected to the printhead by a an ink supply harness, there being a disconnect coupling between the reservoirs and the printhead; one or more input devices for capturing operator instructions; a processor which accepts operator inputs which are used to configure the printer for producing a particular roll. 
     Preferably the printer further comprises an internal dryer, the dryer located between the printhead and the winding area and adapted to lengthen the path when additional drying is required. 
     Preferably the printer further comprises a transverse cutting mechanism located between the printhead and the winding area and adapted to divide a media web from a wound portion in response to an instruction from the processor. 
     Preferably the printer further comprises a slitting mechanism adapted to longitudinally slit a media web after it has been printed on. 
     Preferably the printer further comprises a bar code scanner which communicates with the processor and through which data is input. 
     Preferably the printer further comprises a well, adapted to retain a tote; the well being located external to the cabinet and adjacent to an exit slot; the well having at each end, spindles for aligning, retaining and removing a core, and for winding wallpaper onto the core. 
     Preferably the printer further comprises on a front exterior surface of the cabinet, a tilting video display for displaying information about wallpaper that the printer may print. 
     Preferably the video display is a touch screen which can receive operator selections for use by the processor. 
     Preferably the well retains a closed tote having a gap through which wallpaper is introduced during winding. 
     Preferably the media cartridge loading area further comprises one or more vertically stacked locations where a media cartridge can be stored. 
     Preferably the printhead is mounted on a rail on which it slides into and out of a printing position across the path. 
     Preferably the path further comprises a pre-heater located before the printhead in the path. 
     Preferably the printer further comprises an air supply and a tube for bringing a supply of air to the printhead which supply prevents media from contacting the printhead. 
     Preferably the printer further comprises a capper motor, the capper motor driving a capping and blotting device; the capping device sealing the printhead when not in use in order to prevent contamination from entering the printheads. 
     Preferably the capping and blotting device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printheads. 
     Preferably the printer further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the path comprises a generally straight path which is self threading. 
     Preferably the pre-heater is a flat platen located below a moving web. 
     Preferably the printer further comprises a door which covers an opening into a lower compartment of the dryer; the door being moveable from a closed position which covers the opening, to an open position in which the media passes through the opening into the lower compartment and out of the compartment, also through the opening. 
     Preferably the slitting mechanism further comprises a pair of rotating brackets between which extend a number of transverse shafts, each shaft having one or more cutters, the end brackets rotatable so that any shaft can be selected, or that no shaft be selected for cutting the media web. 
     In a seventeenth aspect the present invention provides a consumer tote for a roll of wallpaper, the tote comprising a disposable exterior in which is formed a main access flap and a pair of core access openings; the tote having an interior in which is located a disposable core which is aligned with the access openings; both openings exposing a molded coupling, one coupling attached to each end of the core, at least one of the couplings being a driven coupling and adapted to engage a driving spindle that rotates the core. 
     Preferably there is formed a gap between the access flap and an adjacent edge of the exterior, when the flap is closed. 
     Preferably the exterior is formed from a non-metallic textile. 
     Preferably the core is supported at each end an inward facing hub which engages an interior of the core. 
     Preferably each hub surrounded by a bearing surface which locates the hub in a respective access opening. 
     Preferably the bearing surface makes contact with an inside bottom surface of the disposable exterior when the hub is located in the openings. 
     Preferably the bearing surface is circular and connected to the hub by spokes. 
     Preferably at least one hub has an axial coupling feature for engaging a rotating winding spindle. 
     Preferably the coupling comprises a ring of teeth. 
     Preferably the tote further comprises a handle which folds flat against the exterior. 
     Preferably the handle is formed by two similar sub-units which fold from a flat position to a cooperating position in which a handle opening in each sub-unit align to form a grip. 
     Preferably there is formed a gap between the access flap and an adjacent edge of the exterior, when the flap is closed; and each sub-unit has an edge which is affixed to the exterior, adjacent to the gap; the sub-units arranged in a mirror image relationship about the gap. 
     Preferably the tote further comprises one of the access openings exposes a coupling formed on a hub which carries the core; and a visible marker is located on the exterior for indicating the location of the coupling. 
     Preferably the exterior is dimensioned to fit between the loading spindles of a wallpaper printing machine. 
     Preferably the exterior further comprises a viewing window. 
     Preferably the exterior is adapted to hold about 50 meters of wallpaper wound onto a core. 
     Preferably the adjacent edge includes a return lip. 
     Preferably the return lip is folded from the exterior material. 
     Preferably the gap faces an exit slot of a printer when the tote is loaded for winding. 
     In an eighteenth aspect the present invention provides a removable printhead assembly for a printer which prints onto a moving web, comprising a full width stationary printhead located on a rail along which it slides for service and removal; a number of replaceable ink reservoirs which supply the printhead with different inks; the printhead comprising a color printhead which is at least as wide as the web; and the printhead being supplied with the different inks through tubes which can be disconnected so the printhead may be removed. 
     Preferably the printhead is secured to the rail by fasteners which allow the printhead to be removed when the fasteners are disengaged. 
     Preferably the inks are contained in individual reservoirs and a sensor in each reservoir monitors a level which may be displayed to a user of the printer. 
     Preferably the printhead assembly further comprises an air supply which supplies a stream of air, through a supply tube, to a location near the printhead from where the stream impinges onto the web to prevent it from adhering to the printhead. 
     Preferably the printhead assembly further comprises a first coupling which disconnects the printhead from the ink reservoirs. 
     Preferably the printhead assembly further comprises a capping device having a capper motor for sealing the printhead with a moveable cap when not in use in order to prevent contamination from entering the printheads. 
     Preferably the capping device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printhead. 
     Preferably the printhead assembly further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the printhead assembly further comprises a second coupling with which the air supply can be disconnected from the printhead. 
     Preferably the first coupling and the second coupling are formed together as a single unit. 
     Preferably the printhead assembly further comprises a pre-heater located beneath a path followed by the media; the pre-heater located below the media and before the printhead. 
     Preferably the printhead assembly further comprises a dryer in the same path as the printer the dryer adapted to dry the ink deposited by the printer. 
     Preferably the dryer has a compartment located beneath an opening; the opening being essentially in the path; there being a source of heated air located above the opening, the source of heated air adapted to blow heated air into the opening. 
     Preferably the opening is coverable by a door; and the door covers the opening and acts to support the web when the door is closed. 
     Preferably the door pivots to reveal the opening. 
     Preferably the door is operated by a motor that operates a spool; the spool winding and releasing a member which operates the door. 
     Preferably a preheater is located in the path and located before the opening. 
     Preferably the preheater is in the same plane as the door. 
     Preferably the source of heated air comprises a blower which feeds a stream of air into a plenum. 
     Preferably a temperature sensor is located in the plenum. 
     In a nineteenth aspect the present invention provides a self threading printer for producing rolls of wallpaper, comprising a media loading area adapted to support a media cartridge in a position so that a media supply slot of the cartridge is closely adjacent to a pilot guide; a cabinet housing a media path which extends from the pilot guide to a printed media dispensing slot; a printhead located across the media path; a processor which accepts operator inputs which are used to configure the printer for producing a particular roll; a motor within the cabinet for advancing a media web out of the media cartridge; and one or more other motors adapted to urge the media along the path and out of the slot. 
     Preferably the printer further comprises a slitting mechanism in the cabinet adapted to longitudinally slit the media web, to different widths, as required and in accordance with instructions provided by a user. 
     Preferably the printer further comprises a cutting mechanism located between the printhead and the slot and adapted to divide with a transverse cut, the media web in accordance with instructions provided by the processor. 
     Preferably the printer further comprises an internal dryer, the dryer located between the printhead and the slot and adapted to blow hot air onto a printed web. 
     Preferably the motor is responsive to the processor. 
     Preferably the printer further comprises a well, external to the cabinet and adjacent to a printed media dispensing slot; the well having at each end, spindles for aligning, retaining and removing a core, at least one spindle being motorized to rotate the core. 
     Preferably the printer further comprises on a front exterior surface of the cabinet, a video display for displaying information about wallpaper that the printer may print. 
     Preferably the video display is a touch screen which can receive operator selections for use by the processor. 
     Preferably the media cartridge resides in the loading area with a handle accessible through a service door which provides access to the area. 
     Preferably the media cartridge loading area further comprises one or more empty locations where a media cartridge can be stored. 
     Preferably the printhead is mounted on a rail on which it slides into and out of a printing position across the path. 
     Preferably the printhead is a multi-color printhead which is supplied by separate ink reservoirs, the reservoirs connected to the printhead by a number of ink supply tubes, there being a tube disconnect coupling between the reservoirs and the printhead. 
     Preferably the printer further comprises an air supply and a tube for bringing a supply of air to the printhead which supply prevents media from sticking to the printhead. 
     Preferably the printer further comprises a capper motor, the capper motor driving a capping device; 
     the capping device sealing the printhead with a cap when not in use, in order to prevent contamination from entering the printheads. 
     Preferably the capper device further comprises a blotter, which moves into and out of position and which is used for absorbing ink fired from the printheads. 
     Preferably the printer further comprises one or more rail microadjusters for accurately adjusting a gap between the printhead and the media onto which it is printing. 
     Preferably the path comprises a generally straight path. 
     Preferably the printer further comprises a pre-heater platen located under the path and before the printhead. 
     Preferably the printer further comprises a door which covers an opening into a lower compartment of the dryer; the door being moveable from a closed position which covers the opening, to an open position in which the media passes through the opening into the lower compartment and out of the compartment, also through the opening. 
     Preferably the media in the lower compartment forms a catenary path in the compartment. 
     In a twentieth aspect the present invention provides a method for producing wallpaper on-demand, comprising the steps of utilizing an on-demand printer comprising a cabinet in which is located a media path which passes a printhead on the way to a dispensing slot; 
     selecting a pattern and a configuration using one or more printer input devices which communicate with a processor to input the pattern and the configuration; and printing a roll of wallpaper, onto a web of blank media, on demand, according to the selected pattern and configuration. 
     Preferably the method further comprises a selected width; and wherein the width is captured as data with a printer input device; and the printer is used to slit the web to the width. 
     Preferably the method further comprises a selected roll length; and wherein the roll length is captured as data with a printer input device; and the printer is used to cut the web to the roll length. 
     Preferably the method further comprises charging a customer only for the length. 
     Preferably the method further comprises acquiring data about pattern or configuration from a touch screen display. 
     Preferably the method further comprises providing the printer with a scanner on a tether for capturing data that specifies a selected pattern or other data. 
     Preferably the method further comprises allowing the customer to select a media type and using that media type in a replaceable media cartridge in the printer. 
     Preferably the pattern is selected from printed swatches which correspond to patterns that the printer is able to print on demand. 
     Preferably the method further comprises providing a plurality of swatches; assigning a symbol to each swatch; using the symbol as an input to a printer input device. 
     Preferably the configuration comprises one or more parameters selected from the group comprising: roll length, a roll slitting arrangement, one or more modifications to the pattern, or a media type to be printed on. 
     Preferably the configuration comprises both roll length and a roll width slitting arrangement. 
     Preferably utilizing an on-demand printer further comprises loading a media canister into the printer, the canister containing an unprinted web of media; and using a motor in the printer to advance the unprinted web into the path; automatically threading the media from the loading area, to the dispensing slot. 
     Preferably utilizing an on-demand printer further comprises loading a disposable core into a winding area adjacent to the dispensing slot; winding a printed roll of wallpaper onto a core; and severing the printed roll on the core from the web. 
     Preferably utilizing an on-demand printer further comprises severing the printed roll on the core from the web using an automated cutting mechanism inside the printer, the cutting mechanism receiving a signal for commencing cutting from the processor. 
     Preferably the core is contained within a tote during winding. 
     Preferably the method further comprises drying the web after it is printed on but before it is dispensed by the printer. 
     Preferably the method further comprises drying the web after it is printed on but before it is dispensed by the printer. 
     Preferably the method further comprises allowing a customer to design a custom pattern defined by data; using the one or more input devices to capture the data; and printing the custom pattern on demand. 
     Preferably the method further comprises selling printed rolls as they are produced to eliminate printed wallpaper inventory. 
     Preferably the media is printed by the printhead at a rate exceeding 0.02 square meters per second (775 square feet per hour).” 
     Preferably the media is printed by the printhead at a rate exceeding 0.1 square meters per second (3875 square feet per hour).” 
     Preferably the media is printed by the printhead at a rate exceeding 0.2 square meters per second (7750 square feet per hour).” 
     Preferably the printhead has more than 7680 nozzles. 
     Preferably the printhead has more than 20,000 nozzles. 
     Preferably the printhead has more than 100,000 nozzles. 
     Preferably the printhead has more than 250,000 nozzles. 
     Preferably the printhead prints ink drops with a volume of less than 5 picoliters 
     Preferably the printhead prints ink drops with a volume of less than 3 picoliters 
     Preferably the printhead prints ink drops with a volume of less than 1.5 picoliters 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a perspective view of a wallpaper printer according to the teachings of the present invention; 
         FIG. 2  is a perspective view of a typical retail setting, illustrating the deployment of the present invention; 
         FIG. 3  is an exploded perspective view of a wallpaper printer of the type depicted in  FIG. 1 ; 
         FIG. 4  is a perspective view of a wallpaper printer with a service door open; 
         FIG. 5  is a cross section through the device depicted in  FIG. 1 ; 
         FIG. 6  is a detail of the cross section depicted in  FIG. 5 ; 
         FIG. 7  is a cross section through a wallpaper printer depicting a wallpaper production paper path; 
         FIG. 8A  is a top plan view of a dryer cabinet; 
         FIG. 8B  is an elevation of a dryer cabinet; 
         FIG. 8C  is a side elevation of a dryer cabinet; 
         FIG. 9  is a perspective view of a dryer cabinet; 
         FIG. 10  is a perspective view of the printhead and ink harness; 
         FIG. 11  is another perspective view of the printhead and ink harness showing removal of the printhead; 
         FIG. 12  is a perspective view of a slitter module; 
         FIG. 13  is another perspective of a slitter module showing the transverse cutter; 
         FIGS. 14A and 14B  are perspective views of a media cartridge; 
         FIG. 15  is a perspective view of the media cartridge depicted in  FIG. 14  with the case open; 
         FIG. 16  in an exploded perspective of an interior of a media cartridge; 
         FIG. 17A to 17D  are various views of the media cartridge depicted in  FIGS. 14-16 ; 
         FIG. 18  is a cross section through a media cartridge; 
         FIG. 19  is a perspective view of a carry container or finished wallpaper product; and 
         FIG. 20  is an exploded perspective of the container depicted in  FIG. 19 ; 
         FIG. 21  shows a perspective view of a printhead assembly in accordance with an embodiment of the present invention; 
         FIG. 22  shows the opposite side of the printhead assembly of  FIG. 21 ; 
         FIG. 23  shows a sectional view of the printhead assembly of  FIG. 21 ; 
         FIG. 24A  illustrates a portion of a printhead module that is incorporated in the printhead assembly of  FIG. 21 ; 
         FIG. 24B  illustrates a lid portion of the printhead module of  FIG. 24A ; 
         FIG. 25A  shows a top view of a printhead tile that forms a portion of the printhead module of  FIG. 24A ; 
         FIG. 25B  shows a bottom view of the printhead tile of  FIG. 25A ; 
         FIG. 26  illustrates electrical connectors for printhead integrated circuits that are mounted to the printhead tiles as shown in  FIG. 25A ; 
         FIG. 27  illustrates a connection that is made between the printhead module of  FIG. 24A  and the underside of the printhead tile of  FIGS. 25A and 25B ; 
         FIG. 28  illustrates a “female” end portion of the printhead module of  FIG. 24A ; 
         FIG. 29  illustrates a “male” end portion of the printhead module of  FIG. 24A ; 
         FIG. 30  illustrates a fluid delivery connector for the male end portion of  FIG. 29 ; 
         FIG. 31  illustrates a fluid delivery connector for the female end portion of  FIG. 28 ; 
         FIG. 32  illustrates the fluid delivery connector of  FIG. 30  or  31  connected to fluid delivery tubes; 
         FIG. 33  illustrates a tubular portion arrangement of the fluid delivery connectors of  FIGS. 30 and 31 ; 
         FIG. 34A  illustrates a capping member for the female and male end portions of  FIGS. 28 and 29 ; 
         FIG. 34B  illustrates the capping member of  FIG. 34A  applied to the printhead module of  FIG. 24A ; 
         FIG. 35A  shows a sectional (skeletal) view of a support frame of a casing of the printhead assembly of  FIG. 21 ; 
         FIGS. 35B and 35C  show perspective views of the support frame of  FIG. 35A  in upward and downward orientations, respectively; 
         FIG. 36  illustrates a printed circuit board (PCB) support that forms a portion of the printhead assembly of  FIG. 21 ; 
         FIGS. 37A ,  37 B show side and rear perspective views of the PCB support of  FIG. 36 ; 
         FIG. 38A  illustrates circuit components carried by a PCB supported by the PCB support of  FIG. 36 ; 
         FIG. 38B  shows an opposite side perspective view of the PCB and the circuit components of  FIG. 38A ; 
         FIG. 39A  shows a side view illustrating further components attached to the PCB support of  FIG. 36 ; 
         FIG. 39B  shows a rear side view of a pressure plate that forms a portion of the printhead assembly of  FIG. 21 ; 
         FIG. 40  shows a front view illustrating the further components of  FIG. 39 ; 
         FIG. 41  shows a perspective view illustrating the further components of  FIG. 39 ; 
         FIG. 42  shows a front view of the PCB support of  FIG. 36 ; 
         FIG. 42A  shows a side sectional view taken along the line I-I in  FIG. 42 ; 
         FIG. 42B  shows an enlarged view of the section A of  FIG. 42A ; 
         FIG. 42C  shows a side sectional view taken along the line II-II in  FIG. 42 ; 
         FIG. 42D  shows an enlarged view of the section B of  FIG. 42C ; 
         FIG. 42E  shows an enlarged view of the section C of  FIG. 42C ; 
         FIG. 43  shows a side view of a cover portion of the casing of the printhead assembly of  FIG. 21 ; 
         FIG. 44  illustrates a plurality of the PCB supports of  FIG. 36  in a modular assembly; 
         FIG. 45  illustrates a connecting member that is carried by two adjacent PCB supports of  FIG. 44  and which is used for interconnecting PCBs that are carried by the PCB supports; 
         FIG. 46  illustrates the connecting member of  FIG. 45  interconnecting two PCBs; 
         FIG. 47  illustrates the interconnection between two PCBs by the connecting member of  FIG. 45 ; 
         FIG. 48  illustrates a connecting region of busbars that are located in the printhead assembly of  FIG. 21 ; 
         FIG. 49  shows a perspective view of an end portion of a printhead assembly in accordance with an embodiment of the present invention; 
         FIG. 50  illustrates a connector arrangement that is located in the end portion of the printhead assembly as shown in  FIG. 49 ; 
         FIG. 51  illustrates the connector arrangement of  FIG. 50  housed in an end housing and plate assembly which forms a portion of the printhead assembly; 
         FIGS. 52A and 52B  show opposite side views of the connector arrangement of  FIG. 50 ; 
         FIG. 52C  illustrates a fluid delivery connection portion of the connector arrangement of  FIG. 50 ; 
         FIG. 53A  illustrates a support member that is located in a printhead assembly in accordance with an embodiment of the present invention; 
         FIG. 53B  shows a sectional view of the printhead assembly with the support member of  FIG. 53A  located therein; 
         FIG. 53C  illustrates a part of the printhead assembly of  FIG. 53B  in more detail; 
         FIG. 54  illustrates the connector arrangement of  FIG. 50  housed in the end housing and plate assembly of  FIG. 51  attached to the casing of the printhead assembly; 
         FIG. 55A  shows an exploded perspective view of the end housing and plate assembly of  FIG. 51 ; 
         FIG. 55B  shows an exploded perspective view of an end housing and plate assembly which forms a portion of the printhead assembly of  FIG. 21 ; 
         FIG. 56  shows a perspective view of the printhead assembly when in a form which uses both of the end housing and plate assemblies of  FIGS. 55A and 55B ; 
         FIG. 57  illustrates a connector arrangement housed in the end housing and plate assembly of  FIG. 55B ; 
         FIGS. 58A and 58B  shows opposite side views of the connector arrangement of  FIG. 57 ; 
         FIG. 59  illustrates an end plate when attached to the printhead assembly of  FIG. 49 ; 
         FIG. 60  illustrates data flow and functions performed by a print engine controller integrated circuit that forms one of the circuit components shown in  FIG. 38A ; 
         FIG. 61  illustrates the print engine controller integrated circuit of  FIG. 60  in the context of an overall printing system architecture; 
         FIG. 62  illustrates the architecture of the print engine controller integrated circuit of  FIG. 61 ; 
         FIG. 63  shows an exploded view of a fluid distribution stack of elements that form the printhead tile of  FIG. 25A ; 
         FIG. 64  shows a perspective view (partly in section) of a portion of a nozzle system of a printhead integrated circuit that is incorporated in the printhead module of the printhead assembly of  FIG. 21 ; 
         FIG. 65  shows a vertical sectional view of a single nozzle (of the nozzle system shown in  FIG. 64 ) in a quiescent state; 
         FIG. 66  shows a vertical sectional view of the nozzle of  FIG. 65  at an initial actuation state; 
         FIG. 67  shows a vertical sectional view of the nozzle of  FIG. 66  at a later actuation state; 
         FIG. 68  shows in perspective a partial vertical sectional view of the nozzle of  FIG. 65 , at the actuation state shown in  FIG. 66 ; 
         FIG. 69  shows in perspective a vertical section of the nozzle of  FIG. 65 , with ink omitted; 
         FIG. 70  shows a vertical sectional view of the nozzle of  FIG. 69 ; 
         FIG. 71  shows in perspective a partial vertical sectional view of the nozzle of  FIG. 65 , at the actuation state shown in  FIG. 66 ; 
         FIG. 72  shows a plan view of the nozzle of  FIG. 65 ; and 
         FIG. 73  shows a plan view of the nozzle of  FIG. 65  with lever arm and movable nozzle portions omitted. 
     
    
    
     BEST MODE AND OTHER EMBODIMENTS OF THE INVENTION 
     1. Exterior Overview 
     As shown in  FIG. 1  a wallpaper printer  100  comprises a cabinet  102  with exterior features to facilitate the specification of, purchase of, and packaging of wallpaper which is selected and printed, on-demand, for example at a point of sale. The cabinet  102  includes a tilting touch screen interface  104  such as an LCD TFT screen which is positioned at a convenient height for a standing person. The cabinet also supports a pistol grip type barcode scanner  108  which serves as a data capture device and input. The scanner  108  is preferably attached to the cabinet  102  by a data cable or a tether  110 , even if the scanner  108  operates over a wireless network. 
     The cabinet  102  includes a winding area, in this example taking the form of an exterior well  106  for receiving a container for printed wallpaper, as will be further explained. The well holds a specially configured container  208  (see  FIGS. 4 and 5 ). The container holds a winding core onto which is wound a roll of wallpaper for purchase. The well includes a pair of spindles  120 , at least one of which is driven by a motor and which align, engage and rotate the winding core within the container  208 . The cabinet also includes a tape dispenser  112  with a lid which is used by the machine operator to dispense tape for attaching the wallpaper media to the disposable winding core in the container  208 , as will be further explained. 
     Other exterior cabinet features include a vent area  114  on the top of the cabinet for the discharge of heated or moist air. The vent or vent area  114  is covered by a top plate  116 . The cabinet includes one or more service doors  402 . When the service door is open, the media cartridges  400  can be inserted or withdrawn by their handles  1408 . Adjustable feet  122  may be provided. The cabinet is preferably built around a frame (see  FIG. 3 ) clad with stainless steel and may be decorated with ornamental insert panels  118 . 
     2. Operation Overview 
     As shown in  FIG. 2 , the wallpaper printer of the present invention  100  can serve as the production facility of a business operation such as a retail operation. In this Figure, it can be seen that wallpaper samples or swatches may be arranged into books or collections  200  and displayed on racks  202  for easy access by consumers. In short, a consumer  204  selects a wallpaper pattern from a collection  200  or bases a selection on the modification of an existing pattern. A machine operator scans an associated barcode or other symbol of that pattern with the scanner  108  or enters an alphanumeric code through the touch screen  104  (or other interface) to the printer&#39;s processor. Rolls of wallpaper are produced in standardized boxes or totes  208 , on demand and according to consumer preferences which are input to the printer. Consumer preferences might include a selection of a pattern, a variation to the basic pattern, a custom pattern, the width and length of the finished product, or the web or substrate type onto which the pattern is printed. 
     After the appropriate selections have been made, a free end of a roll of media (already protruding from the exit slot  206  adjacent to the well  106 ) is taped to a winding core, for example with tape which is provided by the tape dispenser  112  (see  FIG. 1 ). The disposable core (see  2014  in  FIG. 20 ) is supported within a box  208 . As the selected wallpaper is printed and dispensed from the slot  206 , it is wound onto the winding core  2014 . At the end of the production run of a particular roll, the web of printed wallpaper is separated with a transverse knife located with the cabinet. By further advancing the winding core, the training end of the roll is taken up into the container  208 . When the winding is complete winding spindle may be disengaged from the box  208  allowing it to be withdrawn from the well  106  (see  FIG. 1 ). 
     In some embodiments, a consumer of wallpaper may operate the printer. In other embodiments an operator with some degree of training may operate the machine in accordance with a customer&#39;s requirements, preferences or instructions. 
     It will be appreciated that this kind of operation provides the basis for a wallpaper printing business or the deployment of a franchise based on the technology. 
     In a franchise setting, a head licensor supplies the printer to franchisees. The licensor may also supply the consumables such as inks, media, media cartridges, totes, cores etc. As each of these items potentially require quality control supervision and therefore supply from the licensor in order to ensure the success of the franchise, their consumption by the franchisee may also serve as metrics for franchisee performance and a basis for franchisor remuneration. The franchisor may also supply new patterns and collections of patterns as software, in lieu of actual physical inventory. New patterns insure that the franchisees are able to exploit trends, fashions and seasonal variances in demand, without having to stock any printed media. A printer of this kind may be operated as a networked device, allowing for networked accounting, monitoring, support and pattern supply, also allowing decentralized control over printer operation and maintenance. 
     3. Construction Overview 
     As shown in  FIG. 3 , the cabinet  100  is built around a frame  300 . The frame  300  supports the outer panels, e.g. side panels  302 ,  304 , a rear panel  306 , upper and lower front panels  308   310  and a top panel  312 . The well  106  is shown as having a support spindle  330  and a driven spindle  314 . Tracing the paper flow path backward from the well  106 , the path comprises a slitter and transverse cutter module  316 , a dryer  318 , a full width stationery printhead  320 , and the media cartridges with their drive mechanism  322 . Ink reservoirs  324  are located above the printhead  320 . The reservoirs may have level monitors or quality control means that measure or estimate the amount of ink remaining. This quantity may be transmitted to the printer&#39;s processor where it can be used to generate a display or alarm. The processing capabilities of the device are located in a module or enclosure  340 . The processor operates the unit in accordance to stored technical and business rules in conjunction with operator inputs. 
     As shown in  FIG. 4 , wallpaper media, before it is printed, is contained in cartridges  400 . In this example there is an uppermost cartridge located in a loading area, ready for use and two other cartridges in storage located below it. As will be explained, the printer is self threading and no manual intervention is required by the machine operator to thread the web of unprinted paper into the printing system other than to load the upper cartridge  400  correctly. The service door  402  provides access to the media cartridges  400  and required machine interfaces as well as to the ink reservoirs  324 . Ink reservoirs  324  hold up to several liters of ink and are easily removed and interchanged through the service door  402 . An instruction panel or display screen  410  may be provided at or near eye level. 
     4. Printhead and Ink 
     The embodiment shown uses one of the applicant&#39;s Memjet™ printheads. A typical example of these printheads is shown in PCT Application No PCT/AU98/00550, the entire contents of which is incorporated herein by reference. 
     As shown in  FIG. 5 , the printhead  500  is preferably a Memjet™ style printhead which delivers 1600 dpi photographic quality reproduction. The style of printhead is fabricated using micro electromechanical techniques so as to deliver an essentially all silicon printhead with 9290 nozzles per inch or more than 250,000 nozzles covering a standard roll width of 27 inches. The media web is delivered past the stationary printhead at 90 feet per minute, allowing wallpaper for a standard sized room to be printed and packaged in about 2 minutes.  FIG. 11  shows the elongated printhead  500  carried by a rail  502 . The rail allows the printhead to be easily removed and installed, for service, maintenance or replacement by sliding motion, into and out of position. 
     Referring again to  FIG. 5 , the printhead is supplied with liquid ink from the reservoirs  324 . The removable reservoirs are located above the printhead  500  and a harness  504  comprising a number of ink supply tubes carries the 6 different ink colors from the 6 reservoirs  324  to the printhead  500 . The liquid ink harness  504  is interrupted by a self sealing coupling  1002 ,  1004  (see  FIG. 11 ). Furthermore, by loosening thumb screws  1006  and disconnecting the ink harness coupling  1002 ,  1004  allows the printhead to be withdrawn from the rail  502 . Also note that an air pump  1010  supplies compressed air through an air hose to the printhead or an area adjacent to it. This supply of air may be used to blow across the nozzles in order to prevent the media from resting on the nozzles. 
     Rail microadjusters  1014  (see  FIGS. 6 and 10 ) are used to accurately adjust the distance or space that defines a gap between the printheads and the media being printed. 
     As shown in  FIG. 6 , a capper motor  602  drives a rotary capping and blotting device. The capping device seals the printheads when not in use in order to prevent dust or contaminants from entering the printheads. It uncaps and rotates to produce an integral blotter, which is used for absorbing ink fired from the printheads during routine printer start-up maintenance. 
     5. Media Path 
     As shown in  FIGS. 5 ,  6  and  7 , the printhead  500  resides in an intermediate portion of a media path which extends from a blank media input near the upper cartridge  400  to the printed wallpaper exit slot near the winding roll  2014  (see  FIG. 20 ). The media path is able to be threaded without user intervention because the media is guided at all times in the path. In some embodiments, the path extends to within the tote or container  208 . The path extends in a generally straight line from cartridge  400 , across a very short gap to between the pilot guides  512 , across a flat pre-heater or platen  510  to a location under the printhead  500  and thereafter across an opening  506  which defines the mouth of the dryer&#39;s drying compartment  520 . The opening into the compartment  520  is covered by a rotating door  508 . The door is closed, except during printing which requires air drying. As shown in  FIG. 7 , the door  508  of the dryer  318  can be opened so that the media web descends, following a catenary path when required, into the compartment  520 , providing additional path length and drying time. The path may form a catenary loop or strictly speaking, a loop portion which is suspended within the compartment from each end. In one embodiment the door  508  is biased into an open position and closed by the action of a winding motor  522  operated by the printer&#39;s processor. 
     After the dryer  318 , the path continues in a generally straight line to the cutting and slitting or module  316 . The media path then extends from the cutting and slitting module  316  through the exit opening  206  of the cabinet. 
     6. The Dryer 
     As shown in  FIGS. 8 and 9 , the removable drying cabinet or module  318  utilizes one or more top mounted blowers or centrifugal fans  800 . The fans  800  provide a supply of air, downward through a plenum  808 , across one or more heating elements  802  that are controlled by a thermal sensor  804 . The stream of heated air is channeled by a tapered duct  806  and blown across the opening  506  (not shown in these Figures). When the door  508  is open, the heated air blows into the drying compartment  520 . Exterior circulation ducts  812  allow air from the drying compartment  520  to be collected and supplied to the intakes  814  of each motor  800 . The ducts extend from vents in the compartment upwardly and may include an upper vent  902  which allows hot or moist air to escape through the vent area  114  of the cabinet. 
     7. The Slitter/Cutter Module 
       FIGS. 12 and 13  illustrate the slitter/cutter module  1200 . The module  1200  comprises a frame, such as a sheet metal frame  1202  having end plates  1204  and  1206 . The paper path through the module  1200  is defined by a pair of entry rollers  1208  and  1210  and a pair of exit rollers  1212  and  1214 . One of the entry rollers  1208  and one of the exit rollers  1212  is powered. Power is supplied to both drive rollers by a drive motor  1216  and a drive belt  1218 . The drive rollers  1208 ,  1212  in conjunction with the idler rollers  1210 ,  1214  serve as a transport mechanism for the wallpaper through the module  1200 . 
     Also located between the side plates  1204 ,  1206  is an optional, slitter gang or mechanism in a rotating carrousel configuration. The slitter gang comprises a separate pair of brackets or end plates  1220  and  1222  between which extend a plurality of slitter rollers  1224 ,  1226 ,  1228  and  1230  and a central stabilizing shaft  1232 . In this example, four independent rollers are depicted along with a stabilizing shaft  1232 . It will be understood that the slitter gang is optional and may be provided either as a single roller or a gang of two or more rollers as illustrated by  FIG. 12 . An actuating motor  1232  rotates the slitter gang into a selected position. A central guide roller  1234  extends between the end plates  1204 ,  1206  and beneath the slitter gang. The guide roller  1234  has a succession of circumferential grooves  1236  formed along its length. The grooves  1236  correspond to the position of each of the blades, cutters or rotating cutting disks  1238  which are formed on each of the slitters  1224 - 1230 . In this way, the guide roller acts as a cutting block and allows the blades  1238  to penetrate the wallpaper when they are rotated into position. In this way, each of the slitters  1224 - 1230  can be rotated into an out of position, as required. 
     As shown in  FIG. 13 , the exit portion of the slitter/cutter module  1200  comprises a transverse cutter  1300 . The cutter blade  1300  is mounted eccentrically between a pair of rotating cams  1302  which are rotated in unison by an actuating motor to provide a circular cutting stroke. The motor may be mounted on an end plate. Actuation of the cutter  1300  divides the wallpaper web. 
     8. Media Supply Cartridge 
       FIGS. 14-18  illustrate the construction of the wallpaper media supply cartridges  400 . Each cartridge comprises, for example, a high density polyethylene molding which forms a hinged case  1400 . The case  1400  includes a top half  1402  and a bottom half  1404  which are held together by hinge such as an integral hinge  1406 . 
     One end face of the cartridge  400  preferably includes a handle  1408 . A second folding handle  1410  may be provided, for ease of handling, along the top of the cartridge  400 . The two halves,  1402 ,  1404 , may be held together by one or more resilient clips  1414 . 
     As shown in  FIG. 16 , the cartridge  400  is preferably loaded by introducing an assembly into the bottom case half. The assembly includes a roll of blank media  1600  on a hollow core  1630  which rotates freely about a shaft  1610 , rollers  1620 ,  1622  and the support moldings  1614 . 
     The shaft  1610  carries a roller support molding  1614  at each end. The may be interchangeable so as to be used at either end. A notch  1632  at each end of the shaft  1610  engages a cooperating nib  1634  on the support moldings. Because the support moldings  1614  are restrained from rotating by locator slots  1636  formed in the cases halves, the shaft does not rotate (but the core  1630  does). The roller support moldings also may include resilient extensions  1617 . Lunettes  1638  at the end of the extensions engage cooperating grooves  1618  formed at the ends of the cartridge drive roller  1620  and idler roller  1622 . The rollers  1620 ,  1622  are supported between the ends of the cartridge  400 , but maintained in proximity to one another and in registry with the shaft  1610  by the support moldings  1614 . The resilient force imposed by the extensions  1616  keep the drive roller  1620  and the idler  1622  in close enough proximity (or in contact) that when the drive roller  1620  is operated on by the media driver motor, the wallpaper medium is dispensed from the dispensing slot  1640  of the cartridge  400 . Further advancing the drive roller  1620  advances the media web into the media path. 
     In some embodiments, the driven roller  1620  is slightly longer than the idler roller  1622 . One case half has an opening  1650  which allows a shaft or spindle to rotate the drive roller  1620  via a coupling half  1652  formed in the roller. The opening may serve as a journal for the shaft  1620 . The idler roller remains fully within the case when the halves are shut. 
     9. Customer Tote 
     As shown in  FIGS. 19 and 20 , a tote or container  1900  for the finished product comprises an elongated folding carton with a central axially directed opening  1902  at each end  1902 . The carton may be disposable and formed from paper, cardboard or any other thin textile. The carton holds about 50 meters of printed wallpaper. As shown in  FIG. 20 , the finished roll of wallpaper  2000  is shown on a core  2008  supported between a pair of support moldings  2000 - 2004 . The core  2008  may be disposable. Each of the support moldings comprises a hub or stub shaft  2006  which is adapted to engage the interior of the core  2008  which carries the printed wallpaper  2000 . The support moldings may have a circumferential bearing surface  2022 , attached to the stub shaft, for example by spokes  2030 , for distributing the load onto the interior bottom and walls of the carton. Each molding,  2002 ,  2004  includes an external shoulder  2010  which is adapted to fit through the openings  1902 . At least one of the moldings  2002  has axially or radially extending teeth  2012  forming a coupling feature which is adapted to be driven by the drive mechanism located within the cradle  106  formed on the front of the cabinet. Other types of coupling features may be used. A viewing window  2020  may be formed in an upper flap of the carton  1900  so that the printed pattern can be viewed with the lid  2022  closed. 
     An edge  1920  of the carton adjacent to the lid  2022  may include a return fold so as to smooth the edge presented to wallpaper as it is wound onto the core. A smooth edge may also be provided by applying a separate anti-friction material. Note the gap  1922  between the lid and the carton. Wallpaper enters the tote through the gap  1922 . 
     The carton  1900  may include folding handles  1910  provided singly or in opposing pairs,  1910 ,  1912 . In some embodiments a handle is provided on either side of the gap  1922 . Folding handles of this kind form a grip when deployed but do not interfere with the location of the box  1900  within the cradle. An arrow  1914  or other visual device printed on the box indicates which end of the carton orients to or corresponds to the driving end of the cradle  106  (see  FIG. 3 ). 
     10. Information Processing 
     The invention has been disclosed with reference to a module  340  in which is placed a processor. It will be understood that the processing capabilities of the printer of the present invention may be physically deployed and interconnected with the hardware and software required for the printer in a number of ways. In this document and the claims, the broad term “processor” is used to refer to the totality of electronic information processing resources required by the printer (regardless of location, platform, arrangement, network, configuration etc.) unless a contrary intention or meaning is indicated. In general the processor is responsible for coordination of the printer&#39;s functions in accordance with the operator inputs. The printer&#39;s functions may include any one or more of: providing operator instruction, creating alerts to system performance, self threading, operation of the printhead and its accessory features, obtaining operator inputs from any of a variety of sources, movement of the web through the printer and out of it, operation of any cutter or slitter, winding of the finished roll onto a spool or into a tote, communication with the operator and driving any display, self diagnosis and report, self maintenance, monitoring system parameters and adjusting printing systems. 
     11. Methods of Operation 
     The device of the present invention is preferably operated as an on demand printer. An operator of the device is able to select a pattern for printing in a number of ways. The pattern may be selected by viewing pattern on the display  104 , or from a collection of printed swatches  200  or by referring to other sources. The identity of the selected pattern is communicated to the printer by the scanner  108  or by a keyboard, the touchscreen  104  or other means. In some embodiments the pattern may be customized by operator input, such as changing the color or scale of a pattern, the spacing of stripes or the combination of patterns. Input devices such as the touchscreen  104  also allow the customer, user or operator to configure the printer for a particular run or job. Configuration information that can be input to the processor includes roll length, slitting requirements, media selection or modifications to the pattern. The totality of inputs are processed and when the printer is ready to print, the operator insures that the web is taped to the core in the tote and that the core and tote are ready for winding. Alerts will be generated by the printer if any system function or parameter indicates that the job will not be printed and wound successfully. This may require the self diagnosis of a variety of physical parameters such as ink fill levels, remaining web length, web tension, end-to-end integrity of the web etc. Information requirement and resources may be parsed and checked as well prior to the initiation of a print run. Once the required roll length has been wound, the tote is severed from the web, either automatically or manually, as required. 
     A detailed description of a preferred embodiment of the printhead will now be described with reference to  FIGS. 21-73 . 
     The printhead assembly  3010  as shown in  FIGS. 21 and 22  is intended for use as a page width printhead in a printing system. That is, a printhead which extends across the width or along the length of a page of print media, e.g., paper, for printing. During printing, the printhead assembly ejects ink onto the print media as it progresses past, thereby forming printed information thereon, with the printhead assembly being maintained in a stationary position as the print media is progressed past. That is, the printhead assembly is not scanned across the page in the manner of a conventional printhead. 
     As can be seen from  FIGS. 21 and 22 , the printhead assembly  3010  includes a casing  3020  and a printhead module  3030 . The casing  3020  houses the dedicated (or drive) electronics for the printhead assembly together with power and data inputs, and provides a structure for mounting the printhead assembly to a printer unit. The printhead module  3030 , which is received within a channel  3021  of the casing  3020  so as to be removable therefrom, includes a fluid channel member  3040  which carries printhead tiles  3050  having printhead integrated circuits  3051  incorporating printing nozzles thereon. The printhead assembly  3010  further includes an end housing  3120  and plate  3110  assembly and an end plate  3111  which are attached to longitudinal ends of the assembled casing  3020  and printhead module  3030 . 
     The printhead module  3030  and its associated components will now be described with reference to  FIGS. 21 to 34B . 
     As shown in  FIG. 23 , the printhead module  3030  includes the fluid channel member  3040  and the printhead tiles  3050  mounted on the upper surface of the member  3040 . 
     As illustrated in  FIGS. 21 and 22 , sixteen printhead tiles  3050  are provided in the printhead module  3030 . However, as will be understood from the following description, the number of printhead tiles and printhead integrated circuits mounted thereon may be varied to meet specific applications of the present invention. 
     As illustrated in  FIGS. 21 and 22 , each of the printhead tiles  3050  has a stepped end region so that, when adjacent printhead tiles  3050  are butted together end-to-end, the printhead integrated circuits  3051  mounted thereon overlap in this region. Further, the printhead integrated circuits  3051  extend at an angle relative to the longitudinal direction of the printhead tiles  3050  to facilitate overlapping between the printhead integrated circuits  3051 . This overlapping of adjacent printhead integrated circuits  3051  provides for a constant pitch between the printing nozzles (described later) incorporated in the printhead integrated circuits  3051  and this arrangement obviated discontinuities in information printed across or along the print media (not shown) passing the printhead assembly  3010 . This overlapping arrangement of the printhead integrated circuits is described in the Applicant&#39;s issued U.S. Pat. No. 6,623,106, which is incorporated herein by reference. 
       FIG. 24  shows the fluid channel member  3040  of the printhead module  3030  which serves as a support member for the printhead tiles  3050 . The fluid channel member  3040  is configured so as to fit within the channel  3021  of the casing  3020  and is used to deliver printing ink and other fluids to the printhead tiles  3050 . To achieve this, the fluid channel member  3040  includes channel-shaped ducts  3041  which extend throughout its length from each end of the fluid channel member  3040 . The channel-shaped ducts  3041  are used to transport printing ink and other fluids from a fluid supply unit (of a printing system to which the printhead assembly  3010  is mounted) to the printhead tiles  3050  via a plurality of outlet ports  3042 . 
     The fluid channel member  3040  is formed by injection moulding a suitable material. Suitable materials are those which have a low coefficient of linear thermal expansion (CTE), so that the nozzles of the printhead integrated circuits are accurately maintained under operational condition (described in more detail later), and have chemical inertness to the inks and other fluids channeled through the fluid channel member  3040 . One example of a suitable material is a liquid crystal polymer (LCP). The injection moulding process is employed to form a body portion  3044   a  having open channels or grooves therein and a lid portion  3044   b  which is shaped with elongate ridge portions  3044   c  to be received in the open channels. The body and lid portions  3044   a  and  3044   b  are then adhered together with an epoxy to form the channel-shaped ducts  3041  as shown in  FIGS. 23 and 24A . However, alternative moulding techniques may be employed to form the fluid channel member  3040  in one piece with the channel-shaped ducts  3041  therein. 
     The plurality of ducts  3041 , provided in communication with the corresponding outlet ports  3042  for each printhead tile  3050 , are used to transport different coloured or types of inks and the other fluids. The different inks can have different colour pigments, for example, black, cyan, magenta and yellow, etc., and/or be selected for different printing applications, for example, as visually opaque inks, infrared opaque inks, etc. Further, the other fluids which can be used are, for example, air for maintaining the printhead integrated circuits  3051  free from dust and other impurities and/or for preventing the print media from coming into direct contact with the printing nozzles provided on the printhead integrated circuits  3051 , and fixative for fixing the ink substantially immediately after being printed onto the print media, particularly in the case of high-speed printing applications. 
     In the assembly shown in  FIG. 24 , seven ducts  3041  are shown for transporting black, cyan, magenta and yellow coloured ink, each in one duct, infrared ink in one duct, air in one duct and fixative in one duct. Even though seven ducts are shown, a greater or lesser number may be provided to meet specific applications. For example, additional ducts might be provided for transporting black ink due to the generally higher percentage of black and white or grayscale printing applications. 
     The fluid channel member  3040  further includes a pair of longitudinally extending tabs  3043  along the sides thereof for securing the printhead module  3030  to the channel  3021  of the casing  3020  (described in more detail later). It is to be understood however that a series of individual tabs could alternatively be used for this purpose. 
     As shown in  FIG. 25A , each of the printhead tiles  3050  of the printhead module  3030  carries one of the printhead integrated circuits  3051 , the latter being electrically connected to a printed circuit board (PCB)  3052  using appropriate contact methods such as wire bonding, with the connections being protectively encapsulated in an epoxy encapsulant  3053 . The PCB  3052  extends to an edge of the printhead tile  3050 , in the direction away from where the printhead integrated circuits  3051  are placed, where the PCB  3052  is directly connected to a flexible printed circuit board (flex PCB)  3080  for providing power and data to the printhead integrated circuit  3051  (described in more detail later). This is shown in  FIG. 26  with individual flex PCBs  3080  extending or “hanging” from the edge of each of the printhead tiles  3050 . The flex PCBs  3080  provide electrical connection between the printhead integrated circuits  3051 , a power supply  3070  and a PCB  3090  (see  FIG. 23 ) with drive electronics  3100  (see  FIG. 38A ) housed within the casing  3020  (described in more detail later). 
       FIG. 25B  shows the underside of one of the printhead tiles  3050 . A plurality of inlet ports  3054  is provided and the inlet ports  3054  are arranged to communicate with corresponding ones of the plurality of outlet ports  3042  of the ducts  3041  of the fluid channel member  3040  when the printhead tiles  3050  are mounted thereon. That is, as illustrated, seven inlet ports  3054  are provided for the outlet ports  3042  of the seven ducts  3041 . Specifically, both the inlet and outlet ports are orientated in an inclined disposition with respect to the longitudinal direction of the printhead module so that the correct fluid, i.e., the fluid being channeled by a specific duct, is delivered to the correct nozzles (typically a group of nozzles is used for each type of ink or fluid) of the printhead integrated circuits. 
     On a typical printhead integrated circuit  3051  as employed in realisation of the present invention, more than 7000 (e.g., 7680) individual printing nozzles may be provided, which are spaced so as to effect printing with a resolution of 1600 dots per inch (dpi). This is achieved by having a nozzle density of 391 nozzles/mm 2  across a print surface width of 20 mm (0.8 in), with each nozzle capable of delivering a drop volume of 1 pl. 
     Accordingly, the nozzles are micro-sized (i.e., of the order of 10 −6  metres) and as such are not capable of receiving a macro-sized (i.e., millimetric) flows of ink and other fluid as presented by the inlet ports  3054  on the underside of the printhead tile  3050 . Each printhead tile  3050 , therefore, is formed as a fluid distribution stack  3500  (see  FIG. 63 ), which includes a plurality of laminated layers, with the printhead integrated circuit  3051 , the PCB  3052 , and the epoxy  3053  provided thereon. 
     The stack  3500  carries the ink and other fluids from the ducts  3041  of the fluid channel member  3040  to the individual nozzles of the printhead integrated circuit  3051  by reducing the macro-sized flow diameter at the inlet ports  3054  to a micro-sized flow diameter at the nozzles of the printhead integrated circuits  3051 . An exemplary structure of the stack which provides this reduction is described in more detail later. 
     Nozzle systems which are applicable to the printhead assembly of the present invention may comprise any type of ink jet nozzle arrangement which can be integrated on a printhead integrated circuit. That is, systems such as a continuous ink system, an electrostatic system and a drop-on-demand system, including thermal and piezoelectric types, may be used. 
     There are various types of known thermal drop-on-demand system which may be employed which typically include ink reservoirs adjacent the nozzles and heater elements in thermal contact therewith. The heater elements heat the ink and create gas bubbles which generate pressures in the ink to cause droplets to be ejected through the nozzles onto the print media. The amount of ink ejected onto the print media and the timing of ejection by each nozzle are controlled by drive electronics. Such thermal systems impose limitations on the type of ink that can be used however, since the ink must be resistant to heat. 
     There are various types of known piezoelectric drop-on-demand system which may be employed which typically use piezo-crystals (located adjacent the ink reservoirs) which are caused to flex when an electric current flows therethrough. This flexing causes droplets of ink to be ejected from the nozzles in a similar manner to the thermal systems described above. In such piezoelectric systems the ink does not have to be heated and cooled between cycles, thus providing for a greater range of available ink types. Piezoelectric systems are difficult to integrate into drive integrated circuits and typically require a large number of connections between the drivers and the nozzle actuators. 
     As an alternative, a micro-electromechanical system (MEMS) of nozzles may be used, such a system including thermo-actuators which cause the nozzles to eject ink droplets. An exemplary MEMS nozzle system applicable to the printhead assembly of the present invention is described in more detail later. 
     Returning to the assembly of the fluid channel member  3040  and printhead tiles  3050 , each printhead tile  3050  is attached to the fluid channel member  3040  such that the individual outlet ports  3042  and their corresponding inlet ports  3054  are aligned to allow effective transfer of fluid therebetween. An adhesive, such as a curable resin (e.g., an epoxy resin), is used for attaching the printhead tiles  3050  to the fluid channel member  3040  with the upper surface of the fluid channel member  3040  being prepared in the manner shown in  FIG. 27 . 
     That is, a curable resin is provided around each of the outlet ports  3042  to form a gasket member  3060  upon curing. This gasket member  3060  provides an adhesive seal between the fluid channel member  3040  and printhead tile  3050  whilst also providing a seal around each of the communicating outlet ports  3042  and inlet ports  3054 . This sealing arrangement facilitates the flow and containment of fluid between the ports. Further, two curable resin deposits  3061  are provided on either side of the gasket member  3060  in a symmetrical manner. 
     The symmetrically placed deposits  3061  act as locators for positioning the printhead tiles  3050  on the fluid channel member  3040  and for preventing twisting of the printhead tiles  3050  in relation to the fluid channel member  3040 . In order to provide additional bonding strength, particularly prior to and during curing of the gasket members  3060  and locators  3061 , adhesive drops  3062  are provided in free areas of the upper surface of the fluid channel member  3040 . A fast acting adhesive, such as cyanoacrylate or the like, is deposited to form the locators  3061  and prevents any movement of the printhead tiles  3050  with respect to the fluid channel member  3040  during curing of the curable resin. 
     With this arrangement, if a printhead tile is to be replaced, should one or a number of nozzles of the associated printhead integrated circuit fail, the individual printhead tiles may easily be removed. Thus, the surfaces of the fluid channel member and the printhead tiles are treated in a manner to ensure that the epoxy remains attached to the printhead tile, and not the fluid channel member surface, if a printhead tile is removed from the surface of the fluid channel member by levering. Consequently, a clean surface is left behind by the removed printhead tile, so that new epoxy can readily be provided on the fluid channel member surface for secure placement of a new printhead tile. 
     The above-described printhead module of the present invention is capable of being constructed in various lengths, accommodating varying numbers of printhead tiles attached to the fluid channel member, depending upon the specific application for which the printhead assembly is to be employed. For example, in order to provide a printhead assembly for A3-sized pagewidth printing in landscape orientation, the printhead assembly may require 16 individual printhead tiles. This may be achieved by providing, for example, four printhead modules each having four printhead tiles, or two printhead modules each having eight printhead tiles, or one printhead module having 16 printhead tiles (as in  FIGS. 21 and 22 ) or any other suitable combination. Basically, a selected number of standard printhead modules may be combined in order to achieve the necessary width required for a specific printing application. 
     In order to provide this modularity in an easy and efficient manner, plural fluid channel members of each of the printhead modules are formed so as to be modular and are configured to permit the connection of a number of fluid channel members in an end-to-end manner. Advantageously, an easy and convenient means of connection can be provided by configuring each of the fluid channel members to have complementary end portions. In one embodiment of the present invention each fluid channel member  3040  has a “female” end portion  3045 , as shown in  FIG. 28 , and a complementary “male” end portion  3046 , as shown in  FIG. 29 . 
     The end portions  3045  and  3046  are configured so that on bringing the male end portion  3046  of one printhead module  3030  into contact with the female end portion  3045  of a second printhead module  3030 , the two printhead modules  3030  are connected with the corresponding ducts  3041  thereof in fluid communication. This allows fluid to flow between the connected printhead modules  3030  without interruption, so that fluid such as ink, is correctly and effectively delivered to the printhead integrated circuits  3051  of each of the printhead modules  3030 . 
     In order to ensure that the mating of the female and male end portions  3045  and  3046  provides an effective seal between the individual printhead modules  3030  a sealing adhesive, such as epoxy, is applied between the mated end portions. 
     It is clear that, by providing such a configuration, any number of printhead modules can suitably be connected in such an end-to-end fashion to provide the desired scale-up of the total printhead length. Those skilled in the art can appreciate that other configurations and methods for connecting the printhead assembly modules together so as to be in fluid communication are within the scope of the present invention. 
     Further, this exemplary configuration of the end portions  3045  and  3046  of the fluid channel member  3040  of the printhead modules  3030  also enables easy connection to the fluid supply of the printing system to which the printhead assembly is mounted. That is, in one embodiment of the present invention, fluid delivery connectors  3047  and  3048  are provided, as shown in  FIGS. 30 and 31 , which act as an interface for fluid flow between the ducts  3041  of the printhead modules  3030  and (internal) fluid delivery tubes  3006 , as shown in  FIG. 32 . The fluid delivery tubes  3006  are referred to as being internal since, as described in more detail later, these tubes  3006  are housed in the printhead assembly  3010  for connection to external fluid delivery tubes of the fluid supply of the printing system. However, such an arrangement is clearly only one of the possible ways in which the inks and other fluids can be supplied to the printhead assembly of the present invention. 
     As shown in  FIG. 30 , the fluid delivery connector  3047  has a female connecting portion  3047   a  which can mate with the male end portion  3046  of the printhead module  3030 . Alternatively, or additionally, as shown in  FIG. 31 , the fluid delivery connector  3048  has a male connecting portion  3048   a  which can mate with the female end portion  3045  of the printhead module  3030 . Further, the fluid delivery connectors  3047  and  3048  include tubular portions  3047   b  and  3048   b , respectively, which can mate with the internal fluid delivery tubes  3006 . The particular manner in which the tubular portions  3047   b  and  3048   b  are configured so as to be in fluid communication with a corresponding duct  3041  is shown in  FIG. 32 . 
     As shown in  FIGS. 30 to 33 , seven tubular portions  3047   b  and  3048   b  are provided to correspond to the seven ducts  3041  provided in accordance with the above-described exemplary embodiment of the present invention. Accordingly, seven internal fluid delivery tubes  3006  are used each for delivering one of the seven aforementioned fluids of black, cyan, magenta and yellow ink, IR ink, fixative and air. However, as previously stated, those skilled in the art clearly understand that more or less fluids may be used in different applications, and consequently more or less fluid delivery tubes, tubular portions of the fluid delivery connectors and ducts may be provided. 
     Further, this exemplary configuration of the end portions of the fluid channel member  3040  of the printhead modules  3030  also enables easy sealing of the ducts  3041 . To this end, in one embodiment of the present invention, a sealing member  3049  is provided as shown in  FIG. 34A , which can seal or cap both of the end portions of the printhead module  3030 . That is, the sealing member  3049  includes a female connecting section  3049   a  and a male connecting section  3049   b  which can respectively mate with the male end portion  3046  and the female end portion  3045  of the printhead modules  3030 . Thus, a single sealing member is advantageously provided despite the differently configured end portions of a printhead module.  FIG. 34B  illustrates an exemplary arrangement of the sealing member  3049  sealing the ducts  3041  of the fluid channel member  3040 . Sealing of the sealing member  3049  and the fluid channel member  3040  interface is further facilitated by applying a sealing adhesive, such as an epoxy, as described above. 
     In operation of a single printhead module  3030  for an A4-sized pagewidth printing application, for example, a combination of one of the fluid delivery connectors  3047  and  3048  connected to one corresponding end portion  3045  and  3046  and a sealing member  3049  connected to the other of the corresponding end portions  3045  and  3046  is used so as to deliver fluid to the printhead integrated circuits  3051 . On the other hand, in applications where the printhead assembly is particularly long, being comprised of a plurality of printhead modules  3030  connected together (e.g., in wide format printing), it may be necessary to provide fluid from both ends of the printhead assembly. Accordingly, one each of the fluid delivery connectors  3047  and  3048  may be connected to the corresponding end portions  3045  and  3046  of the end printhead modules  3030 . 
     The above-described exemplary configuration of the end portions of the printhead module of the present invention provides, in part, for the modularity of the printhead modules. This modularity makes it possible to manufacture the fluid channel members of the printhead modules in a standard length relating to the minimum length application of the printhead assembly. The printhead assembly length can then be scaled-up by combining a number of printhead modules to form a printhead assembly of a desired length. For example, a standard length printhead module could be manufactured to contain eight printhead tiles, which may be the minimum requirement for A4-sized printing applications. Thus, for a printing application requiring a wider printhead having a length equivalent to 32 printhead tiles, four of these standard length printhead modules could be used. On the other hand, a number of different standard length printhead modules might be manufactured, which can be used in combination for applications requiring variable length printheads. 
     However, these are merely examples of how the modularity of the printhead assembly of the present invention functions, and other combinations and standard lengths could be employed and fall within the scope of the present invention. 
     The casing  3020  and its associated components will now be described with reference to  FIGS. 21 to 23  and  35 A to  48 . 
     In one embodiment of the present invention, the casing  3020  is formed as a two-piece outer housing which houses the various components of the printhead assembly and provides structure for the printhead assembly which enables the entire unit to be readily mounted in a printing system. As shown in  FIG. 23 , the outer housing is composed of a support frame  3022  and a cover portion  3023 . Each of these portions  3022  and  3023  are made from a suitable material which is lightweight and durable, and which can easily be extruded to form various lengths. Accordingly, in one embodiment of the present invention, the portions  3022  and  3023  are formed from a metal such as aluminium. 
     As shown in  FIGS. 35A to 35C , the support frame  3022  of the casing  3020  has an outer frame wall  3024  and an inner frame wall  3025  (with respect to the outward and inward directions of the printhead assembly  3010 ), with these two walls being separated by an internal cavity  3026 . The channel  3021  (also see  FIG. 23 ) is formed as an extension of an upper wall  3027  of the support frame  3022  and an arm portion  3028  is formed on a lower region of the support frame  3022 , extending from the inner frame wall  3025  in a direction away from the outer frame wall  3024 . The channel  3021  extends along the length of the support frame  3022  and is configured to receive the printhead module  3030 . The printhead module  3030  is received in the channel  3021  with the printhead integrated circuits  3051  facing in an upward direction, as shown in  FIGS. 21 to 23 , and this upper printhead integrated circuit surface defines the printing surface of the printhead assembly  3010 . 
     As depicted in  FIG. 35A , the channel  3021  is formed by the upper wall  3027  and two, generally parallel side walls  3024   a  and  3029  of the support frame  3022 , which are arranged as outer and inner side walls (with respect to the outward and inward directions of the printhead assembly  3010 ) extending along the length of the support frame  3022 . The two side walls  3024   a  and  3029  have different heights with the taller, outer side wall  3024   a  being defined as the upper portion of the outer frame wall  3024  which extends above the upper wall  3027  of the support frame  3022 , and the shorter, inner side wall  3029  being provided as an upward extension of the upper wall  3027  substantially parallel to the inner frame wall  3025 . The outer side wall  3024   a  includes a recess (groove)  24   b  formed along the length thereof. A bottom surface  3024   c  of the recess  3024   b  is positioned so as to be at the same height as a top surface  3029   a  of the inner side wall  3029  with respect to the upper wall  3027  of the channel  3021 . The recess  3024   b  further has an upper surface  3024   d  which is formed as a ridge which runs along the length of the outer side wall  3024   a  (see  FIG. 35B ). 
     In this arrangement, one of the longitudinally extending tabs  3043  of the fluid channel member  3040  of the printhead module  3030  is received within the recess  3024   b  of the outer side wall  3024   a  so as to be held between the lower and upper surfaces  3024   c  and  3024   d  thereof. Further, the other longitudinally extending tab  3043  provided on the opposite side of the fluid channel member  3040 , is positioned on the top surface  3029   a  of the inner side wall  3029 . In this manner, the assembled printhead module  3030  may be secured in place on the casing  3020 , as will be described in more detail later. 
     Further, the outer side wall  3024   a  also includes a slanted portion  3024   e  along the top margin thereof, the slanted portion  3024   e  being provided for fixing a print media guide  3005  to the printhead assembly  3010 , as shown in  FIG. 23 . This print media guide is fixed following assembly of the printhead assembly and is configured to assist in guiding print media, such as paper, across the printhead integrated circuits for printing without making direct contact with the nozzles of the printhead integrated circuits. 
     As shown in  FIG. 35A , the upper wall  3027  of the support frame  3022  and the arm portion  3028  include lugs  3027   a  and  3028   a , respectively, which extend along the length of the support frame  3022  (see  FIGS. 35B and 35C ). The lugs  3027   a  and  3028   a  are positioned substantially to oppose each other with respect to the inner frame wall  3025  of the support frame  3022  and are used to secure a PCB support  3091  (described below) to the support frame  3022 . 
       FIGS. 35B and 35C  illustrate the manner in which the outer and inner frame walls  3024  and  25  extend for the length of the casing  3020 , as do the channel  3021 , the upper wall  3027 , and its lug  3027   a , the outer and inner side walls  3024   a  and  3029 , the recess  3024   b  and its bottom and upper surfaces  3024   c  and  3024   d , the slanted portion  3024   e , the top surface  3029   a  of the inner side wall  3029 , and the arm portion  3028 , and its lugs  3028   a  and  3028   b  and recessed and curved end portions  3028   c  and  3028   d  (described in more detail later). 
     The PCB support  3091  will now be described with reference to  FIGS. 23 and 36  to  42 E. In  FIG. 23 , the support  3091  is shown in its secured position extending along the inner frame wall  3025  of the support frame  3022  from the upper wall  3027  to the arm portion  3028 . The support  3091  is used to carry the PCB  3090  which mounts the drive electronics  3100  (as described in more detail later). 
     As can be seen particularly in  FIGS. 37A to 37C , the support  3091  includes lugs  3092  on upper and lower surfaces thereof which communicate with the lugs  3027   a  and  3028   a  for securing the support  3091  against the inner frame wall  3025  of the support frame  3022 . A base portion  3093  of the support  3091 , is arranged to extend along the arm portion  3028  of the support frame  3022 , and is seated on the top surfaces of the lugs  3028   a  and  3028   b  of the arm portion  3028  (see  FIG. 35B ) when mounted on the support frame  3022 . 
     The support  3091  is formed so as to locate within the casing  3020  and against the inner frame wall  3025  of the support frame  3022 . This can be achieved by moulding the support  3091  from a plastics material having inherent resilient properties to engage with the inner frame wall  3025 . This also provides the support  3091  with the necessary insulating properties for carrying the PCB  3090 . For example, polybutylene terephthalate (PBT) or polycarbonate may be used for the support  3091 . 
     The base portion  3093  further includes recessed portions  3093   a  and corresponding locating lugs  3093   b , which are used to secure the PCB  3090  to the support  3091  (as described in more detail later). Further, the upper portion of the support  3091  includes upwardly extending arm portions  3094 , which are arranged and shaped so as to fit over the inner side wall  3029  of the channel  3021  and the longitudinally extending tab  3043  of the printhead module  3030  (which is positioned on the top surface  3029   a  of the inner side wall  3029 ) once the fluid channel member  3040  of the printhead module  3030  has been inserted into the channel  3021 . This arrangement provides for securement of the printhead module  3030  within the channel  3021  of the casing  3020 , as is shown more clearly in  FIG. 23 . 
     In one embodiment of the present invention, the extending arm portions  3094  of the support  3091  are configured so as to perform a “clipping” or “clamping” action over and along one edge of the printhead module  3030 , which aids in preventing the printhead module  3030  from being dislodged or displaced from the fully assembled printhead assembly  3010 . This is because the clipping action acts upon the fluid channel member  3040  of the printhead module  3030  in a manner which substantially constrains the printhead module  3030  from moving upwards from the printhead assembly  3010  (i.e., in the z-axis direction as depicted in  FIG. 23 ) due to both longitudinally extending tabs  3043  of the fluid channel member  3040  being held firmly in place (in a manner which will be described in more detail below), and from moving across the longitudinal direction of the printhead module  3030  (i.e., in the y-axis direction as depicted in  FIG. 23 ), which will be also described in more detail below. 
     In this regard, the fluid channel member  3040  of the printhead module  3030  is exposed to a force exerted by the support  3091  directed along the y-axis in a direction from the inner side wall  3029  to the outer side wall  3024   a . This force causes the longitudinally extending tab  3043  of the fluid channel member  3040  on the outer side wall  3024   a  side of the support frame  3022  to be held between the lower and upper surfaces  3024   c  and  3024   d  of the recess  3024   b . This force, in combination with the other longitudinally extending tab  3043  of the fluid channel member  3040  being held between the top surface  3029   a  of the inner side wall  3029  and the extending arm portions  3094  of the support  3091 , acts to inhibit movement of the printhead module  3030  in the z-axis direction (as described in more detail later). 
     However, the printhead module  3030  is still able to accommodate movement in the x-axis direction (i.e., along the longitudinal direction of the printhead module  3030 ), which is desirable in the event that the casing  3020  undergoes thermal expansion and contraction, during operation of the printing system. As the casing is typically made from an extruded metal, such as aluminium, it may undergo dimensional changes due to such materials being susceptible to thermal expansion and contraction in a thermally variable environment, such as is present in a printing unit. 
     That is, in order to ensure the integrity and reliability of the printhead assembly, the fluid channel member  3040  of the printhead module  3030  is firstly formed of material (such as LCP or the like) which will not experience substantial dimensional changes due to environmental changes thereby retaining the positional relationship between the individual printhead tiles, and the printhead module  3030  is arranged to be substantially independent positionally with respect to the casing  3020  (i.e., the printhead module “floats” in the longitudinal direction of the channel  3021  of the casing  3020 ) in which the printhead module  3030  is removably mounted. 
     Therefore, as the printhead module is not constrained in the x-axis direction, any thermal expansion forces from the casing in this direction will not be transferred to the printhead module. Further, as the constraint in the z-axis and y-axis directions is resilient, there is some tolerance for movement in these directions. Consequently, the delicate printhead integrated circuits of the printhead modules are protected from these forces and the reliability of the printhead assembly is maintained. 
     Furthermore, the clipping arrangement also allows for easy assembly and disassembly of the printhead assembly by the mere “unclipping” of the PCB support(s) from the casing. In the exemplary embodiment shown in  FIG. 36 , a pair of extending arm portions  3094  is provided; however those skilled in the art will understand that a greater or lesser number is within the scope of the present invention. 
     Referring again to  FIGS. 36 to 37C , the support  3091  further includes a channel portion  3095  in the upper portion thereof. In the exemplary embodiment illustrated, the channel portion  3095  includes three channeled recesses  3095   a ,  3095   b  and  3095   c . The channeled recesses  3095   a ,  3095   b  and  3095   c  are provided so as to accommodate three longitudinally extending electrical conductors or busbars  3071 ,  3072  and  3073  (see  FIG. 22 ) which form the power supply  3070  (see  FIG. 23 ) and which extend along the length of the printhead assembly  3010 . The busbars  3071 ,  3072  and  3073  are conductors which carry the power required to operate the printhead integrated circuits  3051  and the drive electronics  3100  located on the PCB  3090  (shown in  FIG. 38A  and described in more detail later), and may be formed of copper with gold plating, for example. 
     In one embodiment of the present invention, three busbars are used in order to provide for voltages of Vcc (e.g., via the busbar  3071 ), ground (Gnd) (e.g., via the busbar  3072 ) and V+ (e.g., via the busbar  3073 ). Specifically, the voltages of Vcc and Gnd are applied to the drive electronics  3100  and associated circuitry of the PCB  3090 , and the voltages of Vcc, Gnd and V+ are applied to the printhead integrated circuits  3051  of the printhead tiles  3050 . It will be understood by those skilled in the art that a greater or lesser number of busbars, and therefore channeled recesses in the PCB support can be used depending on the power requirements of the specific printing applications. 
     The support  3091  of the present invention further includes (lower) retaining clips  3096  positioned below the channel portion  3095 . In the exemplary embodiment illustrated in  FIG. 36 , a pair of the retaining clips  3096  is provided. The retaining clips  3096  include a notch portion  3096   a  on a bottom surface thereof which serves to assist in securely mounting the PCB  3090  on the support  3091 . To this end, as shown in the exemplary embodiment of  FIG. 38A , the PCB  3090  includes a pair of slots  3097  in a topmost side thereof (with respect to the mounting direction of the PCB  3090 ), which align with the notch portions  3096   a  when mounted so as to facilitate engagement with the retaining clips  3096 . 
     As shown in  FIG. 23 , the PCB  3090  is snugly mounted between the notch portions  3096   a  of the retaining clips  3096  and the afore-mentioned recessed portions  3093   a  and locating lugs  3093   b  of the base portion  3093  of the support  3091 . This arrangement securely holds the PCB  3090  in position so as to enable reliable connection between the drive electronics  3100  of the PCB  3090  and the printhead integrated circuits  3051  of the printhead module  3030 . 
     Referring again to  FIG. 38A , an exemplary circuit arrangement of the PCB  3090  will now be described. The circuitry includes the drive electronics  3100  in the form of a print engine controller (PEC) integrated circuit. The PEC integrated circuit  3100  is used to drive the printhead integrated circuits  3051  of the printhead module  3030  in order to print information on the print media passing the printhead assembly  3010  when mounted to a printing unit. The functions and structure of the PEC integrated circuit  3100  are discussed in more detail later. 
     The exemplary circuitry of the PCB  3090  also includes four connectors  3098  in the upper portion thereof (see  FIG. 38B ) which receive lower connecting portions  3081  of the flex PCBs  3080  that extend from each of the printhead tiles  3050  (see  FIG. 26 ). Specifically, the corresponding ends of four of the flex PCBs  3080  are connected between the PCBs  3052  of four printhead tiles  3050  and the four connectors  3098  of the PCB  3090 . In turn, the connectors  3098  are connected to the PEC integrated circuit  3100  so that data communication can take place between the PEC integrated circuit  3100  and the printhead integrated circuits  3051  of the four printhead tiles  3050 . 
     In the above-described embodiment, one PEC integrated circuit is chosen to control four printhead tiles in order to satisfy the necessary printing speed requirements of the printhead assembly. In this manner, for a printhead assembly having 16 printhead tiles, as described above with respect to  FIGS. 21 and 22 , four PEC integrated circuits are required and therefore four PCB supports  3091  are used. However, it will be understood by those skilled in the art that the number of PEC integrated circuits used to control a number of printhead tiles may be varied, and as such many different combinations of the number of printhead tiles, PEC integrated circuits, PCBs and PCB supports that may be employed depending on the specific application of the printhead assembly of the present invention. Further, a single PEC integrated circuit  3100  could be provided to drive a single printhead integrated circuit  3051 . Furthermore, more than one PEC integrated circuit  3100  may be placed on a PCB  3090 , such that differently configured PCBs  3090  and supports  3091  may be used. 
     It is to be noted that the modular approach of employing a number of PCBs holding separate PEC integrated circuits for controlling separate areas of the printhead advantageously assists in the easy determination, removal and replacement of defective circuitry in the printhead assembly. 
     The above-mentioned power supply to the circuitry of the PCB  3090  and the printhead integrated circuits  3051  mounted to the printhead tiles  3050  is provided by the flex PCBs  3080 . Specifically, the flex PCBs  3080  are used for the two functions of providing data connection between the PEC integrated circuit(s)  3100  and the printhead integrated circuits  3051  and providing power connection between the busbars  3071 ,  3072  and  3073  and the PCB  3090  and the printhead integrated circuits  3051 . In order to provide the necessary electrical connections, the flex PCBs  3080  are arranged to extend from the printhead tiles  3050  to the PCB  3090 . This may be achieved by employing the arrangement shown in  FIG. 23 , in which a resilient pressure plate  3074  is provided to urge the flex PCBs  3080  against the busbars  3071 ,  3072  and  3073 . In this arrangement, suitably arranged electrical connections are provided on the flex PCBs  3080  which route power from the busbars  3071  and  3072  (i.e., Vcc and Gnd) to the connectors  3098  of the PCB  3090  and power from all of the busbars  3071 ,  3072  and  3073  (i.e., Vcc, Gnd and V+) to the PCB  3052  of the printhead tiles  3050 . 
     The pressure plate  3074  is shown in more detail in  FIGS. 39A to 41 . The pressure plate  3074  includes a raised portion (pressure elastomer)  3075  which is positioned on a rear surface of the pressure plate  3074  (with respect to the mounting direction on the support  3091 ), as shown in  FIG. 39B , so as to be aligned with the busbars  3071 ,  3072  and  3073 , with the flex PCBs  3080  lying therebetween when the pressure plate  3074  is mounted on the support  3091 . The pressure plate  3074  is mounted to the support  3091  by engaging holes  3074   a  with corresponding ones of (upper) retaining clips  3099  of the support  3091  which project from the extending arm portions  3094  (see  FIG. 35A ) and holes  3074   b  with the corresponding ones of the (lower) retaining clips  3096 , via tab portions  3074   c  thereof (see  FIG. 40 ). The pressure plate  3074  is formed so as to have a spring-like resilience which urges the flex PCBs  3080  into electrical contact with the busbars  3071 ,  3072  and  3073  with the raised portion  3075  providing insulation between the pressure plate  3074  and the flex PCBs  3080 . 
     As shown most clearly in  FIG. 41 , the pressure plate  3074  further includes a curved lower portion  3074   d  which serves as a means of assisting the demounting of the pressure plate  3074  from the support  3091 . 
     The specific manner in which the pressure plate  3074  is retained on the support  3091  so as to urge the flex PCBs  3080  against the busbars  3071 ,  3072  and  3073 , and the manner in which the extending arm portions  3094  of the support  3091  enable the above-mentioned clipping action will now be fully described with reference to  FIGS. 42 and 42A  to  42 E. 
       FIG. 42  illustrates a front schematic view of the support  3091  in accordance with a exemplary embodiment of the present invention.  FIG. 42A  is a side sectional view taken along the line I-I in  FIG. 42  with the hatched sections illustrating the components of the support  3091  situated on the line I-I. 
       FIG. 42A  particularly shows one of the upper retaining clips  3099 . An enlarged view of this retaining clip  3099  is shown in  FIG. 42B . The retaining clip  3099  is configured so that an upper surface of one of the holes  3074   a  of the pressure plate  3074  can be retained against an upper surface  3099   a  and a retaining portion  3099   b  of the retaining clip  3099  (see  FIG. 41 ). Due to the spring-like resilience of the pressure plate  3074 , the upper surface  3099   a  exerts a slight upwardly and outwardly directed force on the pressure plate  3074  when the pressure plate  3074  is mounted thereon so as to cause the upper part of the pressure plate  3074  to abut against the retaining portion  3099   b.    
     Referring now to  FIG. 42C , which is a side sectional view taken along the line II-II in  FIG. 42 , one of the lower retaining clips  3096  is illustrated. An enlarged view of this retaining clip  3096  is shown in  FIG. 42D . The retaining clip  3096  is configured so that a tab portion  3074   c  of one of the holes  3074   b  of the pressure plate  3074  can be retained against an inner surface  3096   c  of the retaining clip  3096  (see  FIG. 40 ). Accordingly, due to the above-described slight force exerted by the retaining clip  3099  on the upper part of the pressure plate  3074  in a direction away from the support  3091 , the lower part of the pressure plate  3074  is loaded towards the opposite direction, e.g., in an inward direction with respect to the support frame  3022 . Consequently, the pressure plate  3074  is urged towards the busbars  3071 ,  3072  and  3073 , which in turn serves to urge the flex PCBs  3080  in the same direction via the raised portion  3075 , so as to effect reliable contact with the busbars  3071 ,  3072  and  3073 . 
     Returning to  FIG. 42C , in which one of the extending arm portions  3094  is illustrated. An enlarged view of this extending arm portion  3094  is shown in  FIG. 42E . The extending arm portion  3094  is configured so as to be substantially L-shaped, with the foot section of the L-shape located so as to fit over the inner side wall  3029  of the channel  3021  and the longitudinally extending tab  3043  of the fluid channel member  3040  of the printhead module  3030  arranged thereon. As shown in  FIG. 42E , the end of the foot section of the L-shape has an arced surface. This surface corresponds to the edge of a recessed portion  3094   a  provided in each the extending arm portions  3094 , the centre of which is positioned substantially at the line II-II in  FIG. 42  (see  FIGS. 36 and 37C ). The recessed portions  3094   a  are arranged so as to engage with angular lugs  3043   a  regularly spaced along the length of the longitudinally extending tabs  3043  of the fluid channel member  3040  ( FIG. 24A ), so as to correspond with the placement of the printhead tiles  3050 , when the extending arm portions  3094  are clipped over the fluid channel member  3040 . 
     In this position, the arced edge of the recessed portion  3094   a  is contacted with the angled surface of the angular lugs  3043   a  (see  FIG. 24A ), with this being the only point of contact of the extending arm portion  3094  with the longitudinally extending tab  3043 . Although not shown in  FIG. 24A , the longitudinally extending tab  3043  on the other side of the fluid channel member  3040  has similarly angled lugs  3043   a , where the angled surface comes into contact with the upper surface  3024   d  of the recess  3024   b  on the support frame  3022 . 
     As alluded to previously, due to this specific arrangement, at these contact points a downwardly and inwardly directed force is exerted on the fluid channel member  3040  by the extending arm portion  3094 . The downwardly directed force assists to constrain the printhead module  3030  in the channel  3021  in the z-axis direction as described earlier. The inwardly directed force also assists in constraining the printhead module  3030  in the channel  3021  by urging the angular lugs  3043   a  on the opposing longitudinally extending tab  3043  of the fluid channel member  3040  into the recess  3024   b  of the support frame  3020 , where the upper surface  3024   d  of the recess  3024   b  also applies an opposing downwardly and inwardly directed force on the fluid channel member. In this regard the opposing forces act to constrain the range of movement of the fluid channel member  3040  in the y-axis direction. It is to be understood that the two angular lugs  3043   a  shown in  FIG. 24A  for each of the recessed portions  3094   a  are merely an exemplary arrangement of the angular lugs  3043   a.    
     Further, the angular lugs  3043   a  are positioned so as to correspond to the placement of the printhead tiles  3050  on the upper surface of the fluid channel member  3040  so that, when mounted, the lower connecting portions  3081  of each of the flex PCBs  3080  are aligned with the corresponding connectors  3098  of the PCBs  3090  (see  FIGS. 26 and 38B ). This is facilitated by the flex PCBs  3080  having a hole  3082  therein ( FIG. 26 ) which is received by the lower retaining clip  3096  of the support  3091 . Consequently, the flex PCBs  3080  are correctly positioned under the pressure plate  3074  retained by the retaining clip  3096  as described above. 
     Further still, as also shown in  FIGS. 42C and 42E , the (upper) lug  3092  of the support  3091  has an inner surface  3092   a  which is also slightly angled from the normal of the plane of the support  3091  in a direction away from the support  3091 . As shown in  FIGS. 37B and 37C , the upper lugs  3092  are formed as resilient members which are able to hinge with respect to the support  3091  with a spring-like action. Consequently, when mounted to the casing  3020 , a slight force is exerted against the lug  3027   a  of the uppermost face  3027  of the support frame  3022  which assists in securing the support  3091  to the support frame  3022  of the casing  3020  by biasing the (lower) lug  3092  into the recess formed between the lower part of the inner surface  3025  and the lug  3028   a  of the arm portion  3028  of the support frame  3022 . 
     The manner in which the structure of the casing  3020  is completed in accordance with an exemplary embodiment of the present invention will now be described with reference to  FIGS. 21 ,  22 ,  35 A and  43 . 
     As shown in  FIGS. 21 and 22 , the casing  3020  includes the aforementioned cover portion  3023  which is positioned adjacent the support frame  3022 . Thus, together the support frame  3022  and the cover portion  3023  define the two-piece outer housing of the printhead assembly  3010 . The profile of the cover portion  3023  is as shown in  FIG. 43 . 
     The cover portion  3023  is configured so as to be placed over the exposed PCB  3090  mounted to the PCB support  3091  which in turn is mounted to the support frame  3022  of the casing  3020 , with the channel  3021  thereof holding the printhead module  3030 . As a result, the cover portion  3023  encloses the printhead module  3030  within the casing  3020 . 
     The cover portion  3023  includes a longitudinally extending tab  3023   a  on a bottom surface thereof (with respect to the orientation of the printhead assembly  3010 ) which is received in the recessed portion  3028   c  formed between the lug  3028   b  and the curved end portion  3028   d  of the arm portion  3028  of the support frame  3022  (see  FIG. 35A ). This arrangement locates and holds the cover portion  3023  in the casing  3020  with respect to the support frame  3022 . The cover portion  3023  is further held in place by affixing the end plate  3111  or the end housing  3120  via the end plate  3110  on the longitudinal side thereof using screws through threaded portions  3023   b  (see  FIGS. 43 ,  49  and  59 ). The end plates  3110  and/or  111  are also affixed to the support frame  3022  on either longitudinal side thereof using screws through threaded portions  3022   a  and  3022   b  provided in the internal cavity  3026  (see  FIGS. 35A ,  49  and  59 ). Further, the cover portion  3023  has the profile as shown in  FIG. 33 , in which a cavity portion  3023   c  is arranged at the inner surface of the cover portion  3023  (with respect to the inward direction on the printhead assembly  3010 ) for accommodating the pressure plate(s)  3074  mounted to the PCB support(s)  91 . 
     Further, the cover portion may also include fin portions  3023   d  (see also  FIG. 23 ) which are provided for dissipating heat generated by the PEC integrated circuits  3100  during operation thereof. To facilitate this the inner surface of the cover portion  3023  may also be provided with a heat coupling material portion (not shown) which physically contacts the PEC integrated circuits  3100  when the cover portion  3023  is attached to the support frame  3022 . Further still, the cover portion  3023  may also function to inhibit electromagnetic interference (EMI) which can interfere with the operation of the dedicated electronics of the printhead assembly  3010 . 
     The manner in which a plurality of the PCB supports  3091  are assembled in the support frame  3022  to provide a sufficient number of PEC integrated circuits  3100  per printhead module  3030  in accordance with one embodiment of the present invention will now be described with reference to  FIGS. 36 and 44  to  47 . 
     As described earlier, in one embodiment of the present invention, each of the supports  3091  is arranged to hold one of the PEC integrated circuits  3100  which in turn drives four printhead integrated circuits  3051 . Accordingly, in a printhead module  3030  having 16 printhead tiles, for example, four PEC integrated circuits  3100 , and therefore four supports  3091  are required. For this purpose, the supports  3091  are assembled in an end-to-end manner, as shown in  FIG. 44 , so as to extend the length of the casing  3020 , with each of the supports  3091  being mounted and clipped to the support frame  3022  and printhead module  3030  as previously described. In such a way, the single printhead module  3030  of sixteen printhead tiles  3050  is securely held to the casing  3020  along the length thereof. 
     As shown more clearly in  FIG. 36 , the supports  3091  further include raised portions  3091   a  and recessed portions  3091   b  at each end thereof. That is, each edge region of the end walls of the supports  3091  include a raised portion  3091   a  with a recessed portion  3091   b  formed along the outer edge thereof. This configuration produces the abutting arrangement between the adjacent supports  3091  shown in  FIG. 44 . 
     This arrangement of two abutting recessed portions  3091   b  with one raised portion  3091   a  at either side thereof forms a cavity which is able to receive a suitable electrical connecting member  3102  therein, as shown in cross-section in  FIG. 45 . Such an arrangement enables adjacent PCBs  3090 , carried on the supports  3091  to be electrically connected together so that data signals which are input from either or both ends of the plurality of assembled supports  3091 , i.e., via data connectors (described later) provided at the ends of the casing  3020 , are routed to the desired PEC integrated circuits  3100 , and therefore to the desired printhead integrated circuits  3051 . 
     To this end, the connecting members  3102  provide electrical connection between a plurality of pads provided at edge contacting regions on the underside of each of the PCBs  3090  (with respect to the mounting direction on the supports  3091 ). Each of these pads is connected to different regions of the circuitry of the PCB  3090 .  FIG. 46  illustrates the pads of the PCBs as positioned over the connecting member  3102 . Specifically, as shown in  FIG. 46 , the plurality of pads are provided as a series of connection strips  3090   a  and  3090   b  in a substantially central region of each edge of the underside of the PCBs  3090 . 
     As mentioned above, the connecting members  3102  are placed in the cavity formed by the abutting recessed portions  3091   b  of adjacent supports  3091  (see  FIG. 45 ), such that when the PCBs  3090  are mounted on the supports  3091 , the connection strips  3090   a  of one PCB  3090  and the connection strips  3090   b  of the adjacent PCB  3090  come into contact with the same connecting member  3102  so as to provide electrical connection therebetween. 
     To achieve this, the connecting members  3102  may each be formed as shown in  FIG. 47  to be a rectangular block having a series of conducting strips  3104  provided on each surface thereof. Alternatively, the conducting strips  3104  may be formed on only one surface of the connecting members  3102  as depicted in  FIGS. 45 and 3046 . Such a connecting member may typically be formed of a strip of silicone rubber printed to provide sequentially spaced conductive and non-conductive material strips. A shown in  FIG. 47 , these conducting strips  3104  are provided in a 2:1 relationship with the connecting strips  3090   a  and  3090   b  of the PCBs  3090 . That is, twice as many of the conducting strips  3104  are provided than the connecting strips  3090   a  and  3090   b , with the width of the conducting strips  3104  being less than half the width of the connecting strips  3090   a  and  3090   b . Accordingly, any one connecting strip  3090   a  or  90   b  may come into contact with one or both of two corresponding conducting strips  3104 , thus minimising alignment requirements between the connecting members  3104  and the contacting regions of the PCBs  3090 . 
     In one embodiment of the present invention, the connecting strips  3090   a  and  3090   b  are about 0.4 mm wide with a 0.4 mm spacing therebetween, so that two thinner conducting strips  3104  can reliably make contact with only one each of the connecting strips  3090   a  and  3090   b  whilst having a sufficient space therebetween to prevent short circuiting. The connecting strips  3090   a  and  3090   b  and the conducting strips  3104  may be gold plated so as to provide reliable contact. However, those skilled in the art will understand that use of the connecting members and suitably configured PCB supports is only one exemplary way of connecting the PCBs  3090 , and other types of connections are within the scope of the present invention. 
     Additionally, the circuitry of the PCBs  3090  is arranged so that a PEC integrated circuit  3100  of one of the PCB  3090  of an assembled support  3091  can be used to drive not only the printhead integrated circuits  3051  connected directly to that PCB  3090 , but also those of the adjacent PCB(s)  3090 , and further of any non-adjacent PCB(s)  3090 . Such an arrangement advantageously provides the printhead assembly  3010  with the capability of continuous operation despite one of the PEC integrated circuits  3100  and/or PCBs  3090  becoming defective, albeit at a reduced printing speed. 
     In accordance with the above-described scalability of the printhead assembly  3010  of the present invention, the end-to-end assembly of the PCB supports  3091  can be extended up to the required length of the printhead assembly  3010  due to the modularity of the supports  3091 . For this purpose, the busbars  3071 ,  3072  and  3073  need to be extended for the combined length of the plurality of PCB supports  3091 , which may result in insufficient power being delivered to each of the PCBs  3090  when a relatively long printhead assembly  3010  is desired, such as in wide format printing applications. 
     In order to minimise power loss, two power supplies can be used, one at each end of the printhead assembly  3010 , and a group of busbars  3070  from each end may be employed. The connection of these two busbar groups, e.g., substantially in the centre of the printhead assembly  3010 , is facilitated by providing the exemplary connecting regions  3071   a ,  3072   a  and  3073   a  shown in  FIG. 48 . 
     Specifically, the busbars  3071 ,  3072  and  3073  are provided in a staggered arrangement relative to each other and the end regions thereof are configured with the rebated portions shown in  FIG. 48  as connecting regions  3071   a ,  3072   a  and  3073   a . Accordingly, the connecting regions  3071   a ,  3072   a  and  3073   a  of the first group of busbars  3070  overlap and are engaged with the connecting regions  3071   a ,  3072   a  and  3073   a  of the corresponding ones of the busbars  3071 ,  3072  and  3073  of the second group of busbars  3070 . 
     The manner in which the busbars are connected to the power supply and the arrangements of the end plates  3110  and  111  and the end housing(s)  3120  which house these connections will now be described with reference to  FIGS. 21 ,  22  and  49  to  59 . 
       FIG. 49  illustrates an end portion of an exemplary printhead assembly according to one embodiment of the present invention similar to that shown in  FIG. 21 . At this end portion, the end housing  3120  is attached to the casing  3020  of the printhead assembly  3010  via the end plate  3110 . 
     The end housing and plate assembly houses connection electronics for the supply of power to the busbars  3071 ,  3072  and  3073  and the supply of data to the PCBs  3090 . The end housing and plate assembly also houses connections for the internal fluid delivery tubes  3006  to external fluid delivery tubes (not shown) of the fluid supply of the printing system to which the printhead assembly  3010  is being applied. 
     These connections are provided on a connector arrangement  3115  as shown in  FIG. 50 .  FIG. 50  illustrates the connector arrangement  3115  fitted to the end plate  3110  which is attached, via screws as described earlier, to an end of the casing  3020  of the printhead assembly  3010  according to one embodiment of the present invention. As shown, the connector arrangement  3115  includes a power supply connection portion  3116 , a data connection portion  3117  and a fluid delivery connection portion  3118 . Terminals of the power supply connection portion  3116  are connected to corresponding ones of three contact screws  3116   a ,  3116   b ,  3116   c  provided so as to each connect with a corresponding one of the busbars  3071 ,  3072  and  3073 . To this end, each of the busbars  3071 ,  3072  and  3073  is provided with threaded holes in suitable locations for engagement with the contact screws  3116   a ,  3116   b ,  3116   c . Further, the connection regions  3071   a ,  3072   a  and  3073   a  (see  FIG. 48 ) may also be provided at the ends of the busbars  3071 ,  3072  and  3073  which are to be in contact with the contact screws  3116   a ,  3116   b ,  3116   c  so as to facilitate the engagement of the busbars  3071 ,  3072  and  3073  with the connector arrangement  3115 , as shown in  FIG. 51 . 
     In  FIGS. 50 ,  52 A and  52 B, only three contact screws or places for three contact screws are shown, one for each of the busbars. However, the use of a different number of contact screws is within the scope of the present invention. That is, depending on the amount of power being routed to the busbars, in order to provide sufficient power contact it may be necessary to provide two or more contact screws for each busbar (see, for example,  FIGS. 53B and 53C ). Further, as mentioned earlier a greater or lesser number of busbars may be used, and therefore a corresponding greater of lesser number of contact screws. Further still, those skilled in the art will understand that other means of contacting the busbars to the power supply via the connector arrangements as are typical in the art, such as soldering, are within the scope of the present invention. 
     The manner in which the power supply connection portion  3116  and the data connection portion  3117  are attached to the connector arrangement  3115  is shown in  FIGS. 52A and 52B . Further, connection tabs  3118   a  of the fluid delivery connection portion  3118  are attached at holes  3115   a  of the connector arrangement  3115  so as that the fluid delivery connection portion  3118  overlies the data connection portion  3117  with respect to the connector arrangement  3115  (see  FIGS. 50 and 52C ). 
     As seen in  FIGS. 50 and 52C , seven internal and external tube connectors  3118   b  and  118   c  are provided in the fluid delivery connection portion  3118  in accordance with the seven internal fluid delivery tubes  3006 . That is, as shown in  FIG. 54 , the fluid delivery tubes  3006  connect between the internal tube connectors  3118   b  of the fluid delivery connection portion  3118  and the seven tubular portions  3047   b  or  3048   b  of the fluid delivery connector  3047  or  3048 . As stated earlier, those skilled in the art clearly understand that the present invention is not limited to this number of fluid delivery tubes, etc. 
     Returning to  FIGS. 52A and 52B , the connector arrangement  3115  is shaped with regions  3115   b  and  3115   c  so as to be received by the casing  3020  in a manner which facilitates connection of the busbars  3071 ,  3072  and  3073  to the contact screws  3116   a ,  3116   b  and  3116   c  of the power supply connection portion  3116  via region  3115   b  and connection of the end PCB  3090  of the plurality of PCBs  3090  arranged on the casing  3020  to the data connection portion  3117  via region  3115   c.    
     The region  3115   c  of the connector arrangement  3115  is advantageously provided with connection regions (not shown) of the data connection portion  3117  which correspond to the connection strips  3090   a  or  90   b  provided at the edge contacting region on the underside of the end PCB  3090 , so that one of the connecting members  3102  can be used to connect the data connections of the data connection portion  3117  to the end PCB  3090 , and thus all of the plurality of PCBs  3090  via the connecting members  3102  provided therebetween. 
     This is facilitated by using a support member  3112  as shown in  FIG. 53A , which has a raised portion  3112   a  and a recessed portion  3112   b  at one edge thereof which is arranged to align with the raised and recessed portions  3091   a  and  3091   b , respectively, of the end PCB support  3091  (see  FIG. 44 ). The support member  3112  is attached to the rear surface of the end PCB support  3091  by engaging a tab  3112   c  with a slot region  3091   c  on the rear surface of the end PCB support  3091  (see  FIGS. 37B and 37C ), and the region  3115   c  of the connector arrangement  3115  is retained at upper and lower side surfaces thereof by clip portions  3112   d  of the support member  3112  so as that the connection regions of the region  3115   c  are in substantially the same plane as the edge contacting regions on the underside of the end PCB  3090 . 
     Thus, when the end plate  3110  is attached to the end of the casing  3020 , an abutting arrangement is formed between the recessed portions  3112   b  and  3091   b , similar to the abutting arrangement formed between the recessed portions  3091   b  of the adjacent supports  3091  of  FIG. 44 . Accordingly, the connecting member  3102  can be accommodated compactly between the end PCB  3090  and the region  3115   c  of the connector arrangement  3115 . This arrangement is shown in  FIGS. 53B and 33C  for another type of connector arrangement  3125  with a corresponding region  3125   c , which is described in more detail below with respect to  FIGS. 57 ,  58 A and  58 B. 
     This exemplary manner of connecting the data connection portion  3117  to the end PCB  3090  contributes to the modular aspect of the present invention, in that it is not necessary to provide differently configured PCBs  3090  to be arranged at the longitudinal ends of the casing  3020  and the same method of data connection can be retained throughout the printhead assembly  3010 . It will be understood by those skilled in the art however that the provision of additional or other components to connect the data connection portion  3117  to the end PCB  3090  is also included in the scope of the present invention. 
     Returning to  FIG. 50 , it can be seen that the end plate  3110  is shaped so as to conform with the regions  3115   b  and  3115   c  of the connector arrangement  3115 , such that these regions can project into the casing  3020  for connection to the busbars  3071 ,  3072  and  3073  and the end PCB  3090 , and so that the busbars  3071 ,  3072  and  3073  can extend to contact screws  3116   a ,  3116   b  and  3116   c  provided on the connector arrangement  3115 . This particular shape of the end plate  3110  is shown in  FIG. 55A , where regions  3110  and  3110   b  of the end plate  3110  correspond with the regions  3115   b  and  3115   c  of the connector arrangement  3115 , respectively. Further, a region  3110   c  of the end plate  3110  is provided so as to enable connection between the internal fluid delivery tubes  3006  and the fluid delivery connectors  3047  and  3048  of the printhead module  3030 . 
     The end housing  3120  is also shaped as shown in  FIG. 55A , so as to retain the power supply, data and fluid delivery connection portions  3116 ,  3117  and  3118  so that external connection regions thereof, such as the external tube connector  3118   c  of the fluid delivery connection portion  3118  shown in  FIG. 52C , are exposed from the printhead assembly  3010 , as shown in  FIG. 49 . 
       FIG. 55B  illustrates the end plate  3110  and the end housing  3120  which may be provided at the other end of the casing  3020  of the printhead assembly  3010  according to an exemplary embodiment of the present invention. The exemplary embodiment shown in  FIG. 55B , for example, corresponds to a situation where an end housing is provided at both ends of the casing so as to provide power supply and/or fluid delivery connections at both ends of the printhead assembly. Such an exemplary printhead assembly is shown in  FIG. 56 , and corresponds, for example, to the above-mentioned exemplary application of wide format printing, in which the printhead assembly is relatively long. 
     To this end,  FIG. 57  illustrates the end housing and plate assembly for the other end of the casing with the connector arrangement  3125  housed therein. The busbars  3071 ,  3072  and  3073  are shown attached to the connector arrangement  3125  for illustration purposes. As can be seen, the busbars  3071 ,  3072  and  3073  are provided with connection regions  3071   a ,  3072   a  and  3073   a  for engagement with connector arrangement  3125 , similar to that shown in  FIG. 51  for the connector arrangement  3115 . The connector arrangement  3125  is illustrated in more detail in  FIGS. 58A and 58B . 
     As can be seen from  FIGS. 58A and 58B , like the connector arrangement  3115 , the connector arrangement  3125  holds the power supply connection portion  3116  and includes places for contact screws for contact with the busbars  3071 ,  3072  and  3073 , holes  3125   a  for retaining the clips  3118   a  of the fluid delivery portion  3118  (not shown), and regions  3125   b  and  3125   c  for extension into the casing  3020  through regions  3110  and  3110   b  of the end plate  3110 , respectively. However, unlike the connector arrangement  3115 , the connector arrangement  3125  does not hold the data connection portion  3117  and includes in place thereof a spring portion  3125   d.    
     This is because, unlike the power and fluid supply in a relatively long printhead assembly application, it is only necessary to input the driving data from one end of the printhead assembly. However, in order to input the data signals correctly to the plurality of PEC integrated circuits  3100 , it is necessary to terminate the data signals at the end opposite to the data input end. Therefore, the region  3125   c  of the connector arrangement  3125  is provided with termination regions (not shown) which correspond with the edge contacting regions on the underside of the end PCB  3090  at the terminating end. These termination regions are suitably connected with the contacting regions via a connecting member  3102 , in the manner described above. 
     The purpose of the spring portion  3125   d  is to maintain these terminal connections even in the event of the casing  3020  expanding and contracting due to temperature variations as described previously, any effect of which may exacerbated in the longer printhead applications. The configuration of the spring portion  3125   d  shown in  FIGS. 58A and 58B , for example, enables the region  3125   c  to be displaced through a range of distances from a body portion  3125   e  of the connector arrangement  3125 , whilst being biased in a normal direction away from the body portion  3125   e.    
     Thus, when the connector arrangement  3125  is attached to the end plate  3110 , which in turn has been attached to the casing  3020 , the region  3125   c  is brought into abutting contact with the adjacent edge of the end PCB  3090  in such a manner that the spring portion  3125   d  experiences a pressing force on the body of the connector arrangement  3125 , thereby displacing the region  3125   c  from its rest position toward the body portion  3125   e  by a predetermined amount. This arrangement ensures that in the event of any dimensional changes of the casing  3020  via thermal expansion and contraction thereof, the data signals remain terminated at the end of the plurality of PCBs  3090  opposite to the end of data signal input as follows. 
     The PCB supports  3091  are retained on the support frame  3022  of the casing  3020  so as to “float” thereon, similar to the manner in which the printhead module(s)  3030  “float” on the channel  3021  as described earlier. Consequently, since the supports  3091  and the fluid channel members  3040  of the printhead modules  3030  are formed of similar materials, such as LCP or the like, which have the same or similar coefficients of expansion, then in the event of any expansion and contraction of the casing  3020 , the supports  3091  retain their relative position with the printhead module(s)  3030  via the clipping of the extending arm portions  3094 . 
     Therefore, each of the supports  3091  retain their adjacent connections via the connecting members  3102 , which is facilitated by the relatively large overlap of the connecting members  3102  and the connection strips  3090   a  and  3090   b  of the PCBs  3090  as shown in  FIG. 47 . Accordingly, since the PCBs  3090 , and therefore the supports  3091  to which they are mounted, are biased towards the connector arrangement  3115  by the spring portion  3125   d  of the connector arrangement  3125 , then should the casing  3020  expand and contract, any gaps which might otherwise form between the connector arrangements  3115  and  3125  and the end PCBs  3090  are prevented, due to the action of the spring portion  3125   d.    
     Accommodation for any expansion and contraction is also facilitated with respect to the power supply by the connecting regions  3071   a ,  3072   a  and  3073   a  of the two groups of busbars  3070  which are used in the relatively long printhead assembly application. This is because, these connecting regions  3071   a ,  3072   a  and  3073   a  are configured so that the overlap region between the two groups of busbars  3070  allows for the relative movement of the connector arrangements  3115  and  3125  to which the busbars  3071 ,  3072  and  3073  are attached whilst maintaining a connecting overlap in this region. 
     In the examples illustrated in  FIGS. 50 ,  53 B,  53 C and  57 , the end sections of the busbars  3071 ,  3072  and  3073  are shown connected to the connector arrangements  3115  and  3125  (via the contact screws  3116   a ,  3116   b  and  3116   c ) on the front surface of the connector arrangements  3115  and  3125  (with respect to the direction of mounting to the casing  3020 ). Alternatively, the busbars  3071 ,  3072  and  3073  can be connected at the rear surfaces of the connector arrangements  3115  and  3125 . In such an alternative arrangement, even though the busbars  3071 ,  3072  and  3073  thus connected may cause the connector arrangements  3115  and  3125  be slightly displaced toward the cover portion  3023 , the regions  3115   c  and  3125   c  of the connector arrangements  3115  and  3125  are maintained in substantially the same plane as the edge contacting regions of the end PCBs  3090  due to the clip portions  3112   d  of the support members  3112  which retain the upper and lower side surfaces of the regions  3115   c  and  3125   c.    
     Printed circuit boards having connecting regions printed in discrete areas may be employed as the connector arrangements  3115  and  3125  in order to provide the various above-described electrical connections provided thereby. 
       FIG. 59  illustrates the end plate  3111  which may be attached to the other end of the casing  3020  of the printhead assembly  3010  according to an exemplary embodiment of the present invention, instead of the end housing and plate assemblies shown in  FIGS. 55A and 55B . This provides for a situation where the printhead assembly is not of a length which requires power and fluid to be supplied from both ends. For example, in an A4-sized printing application where a printhead assembly housing one printhead module of 16 printhead tiles may be employed. 
     In such a situation therefore, since it is unnecessary specifically to provide a connector arrangement at the end of the printhead module  3030  which is capped by the capping member  3049 , then the end plate  3111  can be employed which serves to securely hold the support frame  3022  and cover portion  3023  of the casing  3020  together via screws secured to the threaded portions  3022   a ,  22   b  and  23   b  thereof, in the manner already described (see also  FIG. 22 ). 
     Further, if it is necessary to provide data signal termination at this end of the plurality of PCBs  3090 , then the end plate  3111  can be provided with a slot section (not shown) on the inner surface thereof (with respect to the mounting direction on the casing  3020 ), which can support a PCB (not shown) having termination regions which correspond with the edge contacting regions of the end PCB  3090 , similar to the region  3125   c  of the connector arrangement  3125 . Also similarly, these termination regions may be suitably connected with the contacting regions via a support member  3112  and a connecting member  3102 . This PCB may also include a spring portion between the termination regions and the end plate  3111 , similar to the spring portion  3125   d  of the connector arrangement  3125 , in case expansion and contraction of the casing  3020  may also cause connection problems in this application. 
     With either the attachment of the end housing  3120  and plate  3110  assemblies to both ends of the casing  3020  or the attachment of the end housing  3120  and plate  3110  assembly to one end of the casing  3020  and the end plate  3111  to the other end, the structure of the printhead assembly according to the present invention is completed. 
     The thus-assembled printhead assembly can then be mounted to a printing unit to which the assembled length of the printhead assembly is applicable. Exemplary printing units to which the printhead module and printhead assembly of the present invention is applicable are as follows. 
     For a home office printing unit printing on A4 and letter-sized paper, a printhead assembly having a single printhead module comprising 11 printhead integrated circuits can be used to present a printhead width of 224 mm. This printing unit is capable of printing at approximately 60 pages per minute (ppm) when the nozzle speed is about 20 kHz. At this speed a maximum of about 1690×10 6  drops or about 1.6896 ml of ink is delivered per second for the entire printhead. This results in a linear printing speed of about 0.32 ms −1  or an area printing speed of about 0.07 sqms −1 . A single PEC integrated circuit can be used to drive all 11 printhead integrated circuits, with the PEC integrated circuit calculating about 1.8 billion dots per second. 
     For a printing unit printing on A3 and tabloid-sized paper, a printhead assembly having a single printhead module comprising 16 printhead integrated circuits can be used to present a printhead width of 325 mm. This printing unit is capable of printing at approximately 120 ppm when the nozzle speed is about 55 kHz. At this speed a maximum of about 6758×10 6  drops or about 6.7584 ml of ink is delivered per second for the entire printhead. This results in a linear printing speed of about 0.87 ms −1  or an area printing speed of about 0.28 sqms −1 . Four PEC integrated circuits can be used to each drive four of the printhead integrated circuits, with the PEC integrated circuits collectively calculating about 7.2 billion dots per second. 
     For a printing unit printing on a roll of wallpaper, a printhead assembly having one or more printhead modules providing 36 printhead integrated circuits can be used to present a printhead width of 732 mm. When the nozzle speed is about 55 kHz, a maximum of about 15206×10 6  drops or about 15.2064 ml of ink is delivered per second for the entire printhead. This results in a linear printing speed of about 0.87 ms −1  or an area printing speed of about 0.64 sqms −1 . Nine PEC integrated circuits can be used to each drive four of the printhead integrated circuits, with the PEC integrated circuits collectively calculating about 16.2 billion dots per second. 
     For a wide format printing unit printing on a roll of print media, a printhead assembly having one or more printhead modules providing 92 printhead integrated circuits can be used to present a printhead width of 1869 mm. 
     When the nozzle speed is in a range of about 15 to 55 kHz, a maximum of about 10598×10 6  to 38861×10 6  drops or about 10.5984 to 38.8608 ml of ink is delivered per second for the entire printhead. This results in a linear printing speed of about 0.24 to 0.87 ms −1  or an area printing speed of about 0.45 to 1.63 sqms −1 . At the lower speeds, six PEC integrated circuits can be used to each drive  16  of the printhead integrated circuits (with one of the PEC integrated circuits driving  12  printhead integrated circuits), with the PEC integrated circuits collectively calculating about 10.8 billion dots per second. At the higher speeds, 23 PEC integrated circuits can be used each to drive four of the printhead integrated circuits, with the PEC integrated circuits collectively calculating about 41.4 billions dots per second. 
     For a “super wide” printing unit printing on a roll of print media, a printhead assembly having one or more printhead modules providing 200 printhead integrated circuits can be used to present a printhead width of 4064 mm. When the nozzle speed is about 15 kHz, a maximum of about 23040×10 6  drops or about 23.04 ml of ink is delivered per second for the entire printhead. This results in a linear printing speed of about 0.24 ms −1  or an area printing speed of about 0.97 sqms −1 . Thirteen PEC integrated circuits can be used to each drive  16  of the printhead integrated circuits (with one of the PEC integrated circuits driving eight printhead integrated circuits), with the PEC integrated circuits collectively calculating about 23.4 billion dots per second. 
     For the above exemplary printing unit applications, the required printhead assembly may be provided by the corresponding standard length printhead module or built-up of several standard length printhead modules. Of course, any of the above exemplary printing unit applications may involve duplex printing with simultaneous double-sided printing, such that two printhead assemblies are used each having the number of printhead tiles given above. Further, those skilled in the art understand that these applications are merely examples and the number of printhead integrated circuits, nozzle speeds and associated printing capabilities of the printhead assembly depends upon the specific printing unit application. 
     Print Engine Controller Integrated Circuit 
     The functions and structure of the PEC integrated circuit applicable to the printhead assembly of the present invention will now be discussed with reference to  FIGS. 60 to 62 . 
     In the above-described exemplary embodiments of the present invention, the printhead integrated circuits  3051  of the printhead assembly  3010  are controlled by the PEC integrated circuits  3100  of the drive electronics  3100 . One or more PEC integrated circuits  3100  is or are provided in order to enable pagewidth printing over a variety of different sized pages. As described earlier, each of the PCBs  3090  supported by the PCB supports  3091  has one PEC integrated circuit  3100  which interfaces with four of the printhead integrated circuits  3051 , where the PEC integrated circuit  3100  essentially drives the printhead integrated circuits  3051  and transfers received print data thereto in a form suitable for printing. 
     An exemplary PEC integrated circuit which is suited to driving the printhead integrated circuits of the present invention is described in the Applicant&#39;s co-pending U.S. patent application Ser. Nos. 09/575,108, 09/575,109, 09/575,110, 09/607,985, 09/607,990 and 09/606,999 , which are incorporated herein by reference. 
     Referring to  FIG. 60 , the data flow and functions performed by the PEC integrated circuit  3100  will be described for a situation where the PEC integrated circuit  3100  is suited to driving a printhead assembly having a plurality of printhead modules  3030 . As described above, the printhead module  3030  of one embodiment of the present invention utilises six channels of fluid for printing. These are:
         Cyan, Magenta and Yellow (CMY) for regular colour printing;   Black (K) for black text and other black or grayscale printing;   Infrared (IR) for tag-enabled applications; and   Fixative (F) to enable printing at high speed.       

     As shown in  FIG. 60 , documents are typically supplied to the PEC integrated circuit  3100  by a computer system or the like, having Raster Image Processor(s) (RIP(s)), which is programmed to perform various processing steps  3131  to  3134  involved in printing a document prior to transmission to the PEC integrated circuit  3100 . These steps typically involve receiving the document data (step  3131 ) and storing this data in a memory buffer of the computer system (step  3132 ), in which page layouts may be produced and any required objects may be added. Pages from the memory buffer are rasterized by the RIP (step  3133 ) and are then compressed (step  3134 ) prior to transmission to the PEC integrated circuit  3100 . Upon receiving the page data, the PEC integrated circuit  3100  processes the data so as to drive the printhead integrated circuits  3051 . 
     Due to the page-width nature of the printhead assembly of the present invention, each page must be printed at a constant speed to avoid creating visible artifacts. This means that the printing speed cannot be varied to match the input data rate. Document rasterization and document printing are therefore decoupled to ensure the printhead assembly has a constant supply of data. In this arrangement, a page is not printed until it is fully rasterized, and in order to achieve a high constant printing speed a compressed version of each rasterized page image is stored in memory. This decoupling also allows the RIP(s) to run ahead of the printer when rasterizing simple pages, buying time to rasterize more complex pages. 
     Because contone colour images are reproduced by stochastic dithering, but black text and line graphics are reproduced directly using dots, the compressed page image format contains a separate foreground bi-level black layer and background contone colour layer. The black layer is composited over the contone layer after the contone layer is dithered (although the contone layer has an optional black component). If required, a final layer of tags (in IR or black ink) is optionally added to the page for printout. 
     Dither matrix selection regions in the page description are rasterized to a contone-resolution bi-level bitmap which is losslessly compressed to negligible size and which forms part of the compressed page image. The IR layer of the printed page optionally contains encoded tags at a programmable density. 
     As described above, the RIP software/hardware rasterizes each page description and compresses the rasterized page image. Each compressed page image is transferred to the PEC integrated circuit  3100  where it is then stored in a memory buffer  3135 . The compressed page image is then retrieved and fed to a page image expander  3136  in which page images are retrieved. If required, any dither may be applied to any contone layer by a dithering means  3137  and any black bi-level layer may be composited over the contone layer by a compositor  3138  together with any infrared tags which may be rendered by the rendering means  3139 . Returning to a description of process steps, the PEC integrated circuit  3100  then drives the printhead integrated circuits  3051  to print the composited page data at step  140  to produce a printed page  141 . 
     In this regard, the process performed by the PEC integrated circuit  3100  can be considered to consist of a number of distinct stages. The first stage has the ability to expand a JPEG-compressed contone CMYK layer, a Group 4 Fax-compressed bi-level dither matrix selection map, and a Group 4 Fax-compressed bi-level black layer, all in parallel. In parallel with this, bi-level IR tag data can be encoded from the compressed page image. The second stage dithers the contone CMYK layer using a dither matrix selected by a dither matrix select map, composites the bi-level black layer over the resulting bi-level K layer and adds the IR layer to the page. A fixative layer is also generated at each dot position wherever there is a need in any of the C, M, Y, K, or IR channels. The last stage prints the bi-level CMYK+IR data through the printhead assembly. 
       FIG. 61  shows an exemplary embodiment of the printhead assembly of the present invention including the PEC integrated circuit(s)  3100  in the context of the overall printing system architecture. As shown, the various components of the printhead assembly includes:
         a PEC integrated circuit  3100  which is responsible for receiving the compressed page images for storage in a memory buffer  3142 , performing the page expansion, black layer compositing and sending the dot data to the printhead integrated circuits  3051 . The PEC integrated circuit  3100  may also communicate with a master Quality Assurance (QA) integrated circuit  3143  and a (replaceable) ink cartridge QA integrated circuit  3144 , and provides a means of retrieving the printhead assembly characteristics to ensure optimum printing;   the memory buffer  3142  for storing the compressed page image and for scratch use during the printing of a given page. The construction and working of memory buffers is known to those skilled in the art and a range of standard integrated circuits and techniques for their use might be utilized in use of the PEC integrated circuit(s)  3100 ; and   the master integrated circuit  3143  which is matched to the replaceable ink cartridge QA integrated circuit  3144 . The construction and working of QA integrated circuits is known to those skilled in the art and a range of known QA processes might be utilized in use of the PEC integrated circuit(s)  3100 ;       

     As mentioned in part above, the PEC integrated circuit  3100  of the present invention essentially performs four basic levels of functionality:
         receiving compressed pages via a serial interface such as an IEEE 1394;   acting as a print engine for producing a page from a compressed form. The print engine functionality includes expanding the page image, dithering the contone layer, compositing the black layer over the contone layer, optionally adding infrared tags, and sending the resultant image to the printhead integrated circuits;   acting as a print controller for controlling the printhead integrated circuits and stepper motors of the printing system; and   serving as two standard low-speed serial ports for communication with the two QA integrated circuits. In this regard, two ports are used, and not a single port, so as to ensure strong security during authentication procedures.       

     These functions are now described in more detail with reference to  FIG. 62  which provides a more specific illustration of the PEC integrated circuit architecture according to an exemplary embodiment of the present invention. 
     The PEC integrated circuit  3100  incorporates a simple micro-controller CPU core  3145  to perform the following functions:
         perform QA integrated circuit authentication protocols via a serial interface  3146  between print pages;   run the stepper motor of the printing system via a parallel interface  3147  during printing to control delivery of the paper to the printhead integrated circuits  3051  for printing (the stepper motor requires a 5 KHz process);   synchronize the various components of the PEC integrated circuit  3100  during printing;   provide a means of interfacing with external data requests (programming registers etc.);   provide a means of interfacing with the corresponding printhead module&#39;s low-speed data requests (such as reading the characterization vectors and writing pulse profiles); and   provide a means of writing the portrait and landscape tag structures to an external DRAM  3148 .       

     In order to perform the page expansion and printing process, the PEC integrated circuit  3100  includes a high-speed serial interface  3149  (such as a standard IEEE 1394 interface), a standard JPEG decoder  3150 , a standard Group 4 Fax decoder  3151 , a custom halftoner/compositor (HC)  3152 , a custom tag encoder  3153 , a line loader/formatter (LLF)  154 , and a printhead interface  3155  (PHI) which communicates with the printhead integrated circuits  3051 . The decoders  3150  and  3151  and the tag encoder  3153  are buffered to the HC  3152 . The tag encoder  3153  establishes an infrared tag(s) to a page according to protocols dependent on what uses might be made of the page. 
     The print engine function works in a double-buffered manner. That is, one page is loaded into the external DRAM  3148  via a DRAM interface  3156  and a data bus  3157  from the high-speed serial interface  3149 , while the previously loaded page is read from the DRAM  3148  and passed through the print engine process. Once the page has finished printing, then the page just loaded becomes the page being printed, and a new page is loaded via the high-speed serial interface  3149 . 
     At the aforementioned first stage, the process expands any JPEG-compressed contone (CMYK) layers, and expands any of two Group 4 Fax-compressed bi-level data streams. The two streams are the black layer (although the PEC integrated circuit  3100  is actually colour agnostic and this bi-level layer can be directed to any of the output inks) and a matte for selecting between dither matrices for contone dithering. At the second stage, in parallel with the first, any tags are encoded for later rendering in either IR or black ink. 
     Finally, in the third stage the contone layer is dithered, and position tags and the bi-level spot layer are composited over the resulting bi-level dithered layer. The data stream is ideally adjusted to create smooth transitions across overlapping segments in the printhead assembly and ideally it is adjusted to compensate for dead nozzles in the printhead assembly. Up to six channels of bi-level data are produced from this stage. 
     However, it will be understood by those skilled in the art that not all of the six channels need be present on the printhead module  3030 . For example, the printhead module  3030  may provide for CMY only, with K pushed into the CMY channels and IR ignored. Alternatively, the position tags may be printed in K if IR ink is not available (or for testing purposes). The resultant bi-level CMYK-IR dot-data is buffered and formatted for printing with the printhead integrated circuits  3051  via a set of line buffers (not shown). The majority of these line buffers might be ideally stored on the external DRAM  3148 . In the final stage, the six channels of bi-level dot data are printed via the PHI  3155 . 
     The HC  3152  combines the functions of halftoning the contone (typically CMYK) layer to a bi-level version of the same, and compositing the spot1 bi-level layer over the appropriate halftoned contone layer(s). If there is no K ink, the HC  3152  is able to map K to CMY dots as appropriate. It also selects between two dither matrices on a pixel-by-pixel basis, based on the corresponding value in the dither matrix select map. The input to the HC  3152  is an expanded contone layer (from the JPEG decoder  146 ) through a buffer  3158 , an expanded bi-level spot1 layer through a buffer  3159 , an expanded dither-matrix-select bitmap at typically the same resolution as the contone layer through a buffer  3160 , and tag data at full dot resolution through a buffer (FIFO)  3161 . 
     The HC  3152  uses up to two dither matrices, read from the external DRAM  3148 . The output from the HC  3152  to the LLF  3154  is a set of printer resolution bi-level image lines in up to six colour planes. Typically, the contone layer is CMYK or CMY, and the bi-level spot1 layer is K. Once started, the HC  3152  proceeds until it detects an “end-of-page” condition, or until it is explicitly stopped via its control register (not shown). 
     The LLF  3154  receives dot information from the HC  3152 , loads the dots for a given print line into appropriate buffer storage (some on integrated circuit (not shown) and some in the external DRAM  3148 ) and formats them into the order required for the printhead integrated circuits  3051 . Specifically, the input to the LLF  3154  is a set of six 32-bit words and a DataValid bit, all generated by the HC  3152 . The output of the LLF  3154  is a set of 190 bits representing a maximum of 15 printhead integrated circuits of six colours. Not all the output bits may be valid, depending on how many colours are actually used in the printhead assembly. 
     The physical placement of the nozzles on the printhead assembly of an exemplary embodiment of the present invention is in two offset rows, which means that odd and even dots of the same colour are for two different lines. The even dots are for line L, and the odd dots are for line L- 2 . In addition, there is a number of lines between the dots of one colour and the dots of another. Since the six colour planes for the same dot position are calculated at one time by the HC  3152 , there is a need to delay the dot data for each of the colour planes until the same dot is positioned under the appropriate colour nozzle. The size of each buffer line depends on the width of the printhead assembly. Since a single PEC integrated circuit  3100  can generate dots for up to 15 printhead integrated circuits  3051 , a single odd or even buffer line is therefore 15 sets of 640 dots, for a total of 9600 bits (1200 bytes). For example, the buffers required for six colour odd dots totals almost 45 KBytes. 
     The PHI  3155  is the means by which the PEC integrated circuit  3100  loads the printhead integrated circuits  3051  with the dots to be printed, and controls the actual dot printing process. It takes input from the LLF  3154  and outputs data to the printhead integrated circuits  3051 . The PHI  3155  is capable of dealing with a variety of printhead assembly lengths and formats. The internal structure of the PHI  3155  allows for a maximum of six colours, eight printhead integrated circuits  3051  per transfer, and a maximum of two printhead integrated circuit  3051  groups which is sufficient for a printhead assembly having 15 printhead integrated circuits  3051  (8.5 inch) printing system capable of printing on A4/Letter paper at full speed. 
     A combined characterization vector of the printhead assembly  3010  can be read back via the serial interface  3146 . The characterization vector may include dead nozzle information as well as relative printhead module alignment data. Each printhead module can be queried via its low-speed serial bus  3162  to return a characterization vector of the printhead module. The characterization vectors from multiple printhead modules can be combined to construct a nozzle defect list for the entire printhead assembly and allows the PEC integrated circuit  3100  to compensate for defective nozzles during printing. As long as the number of defective nozzles is low, the compensation can produce results indistinguishable from those of a printhead assembly with no defective nozzles. 
     Fluid Distribution Stack 
     An exemplary structure of the fluid distribution stack of the printhead tile will now be described with reference to  FIG. 63 . 
       FIG. 63  shows an exploded view of the fluid distribution stack  3500  with the printhead integrated circuit  3051  also shown in relation to the stack  3500 . In the exemplary embodiment shown in  FIG. 63 , the stack  3500  includes three layers, an upper layer  3510 , a middle layer  3520  and a lower layer  3530 , and further includes a channel layer  3540  and a plate  3550  which are provided in that order on top of the upper layer  3510 . Each of the layers  3510 ,  3520  and  3530  are formed as stainless-steel or micro-moulded plastic material sheets. 
     The printhead integrated circuit  3051  is bonded onto the upper layer  3510  of the stack  3500 , so as to overlie an array of holes  3511  etched therein, and therefore to sit adjacent the stack of the channel layer  3540  and the plate  3550 . The printhead integrated circuit  3051  itself is formed as a multi-layer stack of silicon which has fluid channels (not shown) in a bottom layer  3051   a . These channels are aligned with the holes  3511  when the printhead integrated circuit  3051  is mounted on the stack  3500 . In one embodiment of the present invention, the printhead integrated circuits  3051  are approximately 1 mm in width and 21 mm in length. This length is determined by the width of the field of a stepper which is used to fabricate the printhead integrated circuit  3051 . Accordingly, the holes  3511  are arranged to conform to these dimensions of the printhead integrated circuit  3051 . 
     The upper layer  3510  has channels  3512  etched on the underside thereof ( FIG. 63  shows only some of the channels  3512  as hidden detail). The channels  3512  extend as shown so that their ends align with holes  3521  of the middle layer  3520 . Different ones of the channels  3512  align with different ones of the holes  3521 . The holes  3521 , in turn, align with channels  3531  in the lower layer  3530 . 
     Each of the channels  3531  carries a different respective colour or type of ink, or fluid, except for the last channel, designated with the reference numeral  3532 . The last channel  3532  is an air channel and is aligned with further holes  3522  of the middle layer  3520 , which in turn are aligned with further holes  3513  of the upper layer  3510 . The further holes  3513  are aligned with inner sides  3541  of slots  3542  formed in the channel layer  3540 , so that these inner sides  3541  are aligned with, and therefore in fluid-flow communication with, the air channel  3532 , as indicated by the dashed line  30543 . 
     The lower layer  3530  includes the inlet ports  3054  of the printhead tile  3050 , with each opening into the corresponding ones of the channels  3531  and  532 . 
     In order to feed air to the printhead integrated circuit surface, compressed filtered air from an air source (not shown) enters the air channel  3532  through the corresponding inlet port  3054  and passes through the holes  3522  and  3513  and then the slots  3542  in the middle layer  3520 , the upper layer  3510  and the channel layer  3540 , respectively. The air enters into a side surface  3051   b  of the printhead integrated circuit  3051  in the direction of arrows A and is then expelled from the printhead integrated circuit  3051  substantially in the direction of arrows B. A nozzle guard  3051   c  may be further arranged on a top surface of the printhead integrated circuit  3051  partially covering the nozzles to assist in keeping the nozzles clear of print media dust. 
     In order to feed different colour and types of inks and other fluids (not shown) to the nozzles, the different inks and fluids enter through the inlet ports  3054  into the corresponding ones of the channels  3531 , pass through the corresponding holes  3521  of the middle layer  3520 , flow along the corresponding channels  3512  in the underside of the upper layer  3510 , pass through the corresponding holes  3511  of the upper layer  3510 , and then finally pass through the slots  3542  of the channel layer  3540  to the printhead integrated circuit  3051 , as described earlier. 
     In transversing this path, the flow diameters of the inks and fluids are gradually reduced from the macro-sized flow diameter at the inlet ports  3054  to the required micro-sized flow diameter at the nozzles of the printhead integrated circuit  3051 . 
     The exemplary embodiment of the fluid distribution stack shown in  FIG. 63  is arranged to distribute seven different fluids to the printhead integrated circuit, including air, which is in conformity with the earlier described exemplary embodiment of the ducts of the fluid channel member. However, it will be understood by those skilled in the art that a greater or lesser number of fluids may be used depending on the specific printing application, and therefore the fluid distribution stack can be configured as necessary. 
     Nozzles and Actuators 
     An exemplary nozzle arrangement which is suitable for the printhead assembly of the present invention is described in the Applicant&#39;s co-pending/granted applications 
                                                6,227,652   6,213,588   6,213,589   6,231,163   6,247,795       6,394,581   6,244,691   6,257,704   6,416,168   6,220,694       6,257,705   6,247,794   6,234,610   6,247,793   6,264,306       6,241,342   6,247,792   6,264,307   6,254,220   6,234,611       6,302,528   6,283,582   6,239,821   6,338,547   6,247,796       6,557,977   6,390,603   6,362,843   6,293,653   6,312,107       6,227,653   6,234,609   6,238,040   6,188,415   6,227,654       6,209,989   6,247,791   6,336,710   6,217,153   6,416,167       6,243,113   6,283,581   6,247,790   6,260,953   6,267,469       6,273,544   6,309,048   6,420,196   6,443,558   6,439,689       6,378,989   6,848,181   6,634,735   6,299,289   6,299,290       6,425,654   6,623,101   6,406,129   6,505,916   6,457,809       6,550,895   6,457,812   6,428,133   10/407,212   10/407,207       10/683,064   10/683,041   6,390,605   6,322,195   6,612,110       6,480,089   6,460,778   6,305,788   6,426,014   6,364,453       6,457,795   6,315,399   6,338,548   6,540,319   6,328,431       6,328,425   6,991,320   6,595,624   6,417,757   7,095,309       6,854,825   6,623,106   6,672,707   6,588,885   7,075,677       6,428,139   6,575,549   6,425,971   6,383,833   6,652,071       6,793,323   6,659,590   6,676,245   6,464,332   6,478,406       6,439,693   6,502,306   6,428,142   6,390,591   7,018,016       6,328,417   6,322,194   6,382,779   6,629,745   6,565,193       6,609,786   6,609,787   6,439,908   6,684,503   6,755,509       6,692,108   6,672,709   7,086,718   6,672,710   6,669,334       7,152,958   6,824,246   6,669,333   6,820,967   6,736,489       6,719,406   10/728,804   7,128,400   7,108,355   6,991,322       10/728,790   7,118,197   10/728,970   10/728,784   10/728,783       7,077,493   6,962,402   7,147,308   10/728,779                    
which are incorporated herein by reference. Some applications have been temporarily identified by their docket number. These will be replaced by the corresponding USSN (or for PCT cases) International Patent application numbers when available.
 
     This nozzle arrangement will now be described with reference to  FIGS. 64 to 73 . One nozzle arrangement which is incorporated in each of the printhead integrated circuits  3051  mounted on the printhead tiles  3050  (see  FIG. 25A ) includes a nozzle and corresponding actuator.  FIG. 64  shows an array of the nozzle arrangements  3801  formed on a silicon substrate  3815 . The nozzle arrangements are identical, but in one embodiment, different nozzle arrangements are fed with different coloured inks and fixative. It will be noted that rows of the nozzle arrangements  3801  are staggered with respect to each other, allowing closer spacing of ink dots during printing than would be possible with a single row of nozzles. The multiple rows also allow for redundancy (if desired), thereby allowing for a predetermined failure rate per nozzle. 
     Each nozzle arrangement  3801  is the product of an integrated circuit fabrication technique. As illustrated, the nozzle arrangement  3801  is constituted by a micro-electromechanical system (MEMS). 
     For clarity and ease of description, the construction and operation of a single nozzle arrangement  3801  will be described with reference to  FIGS. 65 to 73 . 
     Each printhead integrated circuit  3051  includes a silicon wafer substrate  3815 . 0.42 Micron 1 P4M 12 volt CMOS microprocessing circuitry is positioned on the silicon wafer substrate  3815 . 
     A silicon dioxide (or alternatively glass) layer  3817  is positioned on the wafer substrate  3815 . The silicon dioxide layer  3817  defines CMOS dielectric layers. CMOS top-level metal defines a pair of aligned aluminium electrode contact layers  3830  positioned on the silicon dioxide layer  3817 . Both the silicon wafer substrate  3815  and the silicon dioxide layer  3817  are etched to define an ink inlet channel  3814  having a generally circular cross section (in plan). An aluminium diffusion barrier  3828  of CMOS metal 1, CMOS metal 2/3 and CMOS top level metal is positioned in the silicon dioxide layer  3817  about the ink inlet channel  3814 . The diffusion barrier  3828  serves to inhibit the diffusion of hydroxyl ions through CMOS oxide layers of the drive circuitry layer  3817 . 
     A passivation layer in the form of a layer of silicon nitride  831  is positioned over the aluminium contact layers  3830  and the silicon dioxide layer  3817 . Each portion of the passivation layer  3831  positioned over the contact layers  3830  has an opening  3832  defined therein to provide access to the contacts  3830 . 
     The nozzle arrangement  3801  includes a nozzle chamber  3829  defined by an annular nozzle wall  3833 , which terminates at an upper end in a nozzle roof  3834  and a radially inner nozzle rim  3804  that is circular in plan. The ink inlet channel  3814  is in fluid communication with the nozzle chamber  3829 . At a lower end of the nozzle wall, there is disposed a movable rim  3810 , that includes a movable seal lip  3840 . An encircling wall  3838  surrounds the movable nozzle, and includes a stationary seal lip  3839  that, when the nozzle is at rest as shown in  FIG. 65 , is adjacent the moving rim  3810 . A fluidic seal  3811  is formed due to the surface tension of ink trapped between the stationary seal lip  3839  and the moving seal lip  3840 . This prevents leakage of ink from the chamber whilst providing a low resistance coupling between the encircling wall  3838  and the nozzle wall  3833 . 
     As best shown in  FIG. 72 , a plurality of radially extending recesses  3835  is defined in the roof  3834  about the nozzle rim  3804 . The recesses  3835  serve to contain radial ink flow as a result of ink escaping past the nozzle rim  3804 . 
     The nozzle wall  3833  forms part of a lever arrangement that is mounted to a carrier  3836  having a generally U-shaped profile with a base  3837  attached to the layer  3831  of silicon nitride. 
     The lever arrangement also includes a lever arm  3818  that extends from the nozzle walls and incorporates a lateral stiffening beam  3822 . The lever arm  3818  is attached to a pair of passive beams  3806 , formed from titanium nitride (TiN) and positioned on either side of the nozzle arrangement, as best shown in  FIGS. 68 and 71 . The other ends of the passive beams  3806  are attached to the carrier  3836 . 
     The lever arm  3818  is also attached to an actuator beam  3807 , which is formed from TiN. It will be noted that this attachment to the actuator beam is made at a point a small but critical distance higher than the attachments to the passive beam  3806 . 
     As best shown in  FIGS. 68 and 71 , the actuator beam  3807  is substantially U-shaped in plan, defining a current path between the electrode  3809  and an opposite electrode  3841 . Each of the electrodes  3809  and  3841  is electrically connected to a respective point in the contact layer  3830 . As well as being electrically coupled via the contacts  3809 , the actuator beam is also mechanically anchored to anchor  3808 . The anchor  3808  is configured to constrain motion of the actuator beam  3807  to the left of  FIGS. 65 to 67  when the nozzle arrangement is in operation. 
     The TiN in the actuator beam  3807  is conductive, but has a high enough electrical resistance that it undergoes self-heating when a current is passed between the electrodes  3809  and  3841 . No current flows through the passive beams  3806 , so they do not expand. 
     In use, the device at rest is filled with ink  3813  that defines a meniscus  803  under the influence of surface tension. The ink is retained in the chamber  3829  by the meniscus, and will not generally leak out in the absence of some other physical influence. 
     As shown in  FIG. 66 , to fire ink from the nozzle, a current is passed between the contacts  3809  and  3841 , passing through the actuator beam  3807 . The self-heating of the beam  3807  due to its resistance causes the beam to expand. The dimensions and design of the actuator beam  3807  mean that the majority of the expansion in a horizontal direction with respect to  FIGS. 65 to 67 . The expansion is constrained to the left by the anchor  3808 , so the end of the actuator beam  3807  adjacent the lever arm  3818  is impelled to the right. 
     The relative horizontal inflexibility of the passive beams  3806  prevents them from allowing much horizontal movement the lever arm  3818 . However, the relative displacement of the attachment points of the passive beams and actuator beam respectively to the lever arm causes a twisting movement that causes the lever arm  3818  to move generally downwards. The movement is effectively a pivoting or hinging motion. However, the absence of a true pivot point means that the rotation is about a pivot region defined by bending of the passive beams  3806 . 
     The downward movement (and slight rotation) of the lever arm  3818  is amplified by the distance of the nozzle wall  3833  from the passive beams  3806 . The downward movement of the nozzle walls and roof causes a pressure increase within the chamber  3029 , causing the meniscus to bulge as shown in  FIG. 66 . It will be noted that the surface tension of the ink means the fluid seal  3011  is stretched by this motion without allowing ink to leak out. 
     As shown in  FIG. 67 , at the appropriate time, the drive current is stopped and the actuator beam  3807  quickly cools and contracts. The contraction causes the lever arm to commence its return to the quiescent position, which in turn causes a reduction in pressure in the chamber  3829 . The interplay of the momentum of the bulging ink and its inherent surface tension, and the negative pressure caused by the upward movement of the nozzle chamber  3829  causes thinning, and ultimately snapping, of the bulging meniscus to define an ink drop  3802  that continues upwards until it contacts the adjacent print media. 
     Immediately after the drop  3802  detaches, the meniscus forms the concave shape shown in  FIG. 65 . Surface tension causes the pressure in the chamber  3829  to remain relatively low until ink has been sucked upwards through the inlet  3814 , which returns the nozzle arrangement and the ink to the quiescent situation shown in  FIG. 65 . 
     As best shown in  FIG. 68 , the nozzle arrangement also incorporates a test mechanism that can be used both post-manufacture and periodically after the printhead assembly is installed. The test mechanism includes a pair of contacts  3820  that are connected to test circuitry (not shown). A bridging contact  3819  is provided on a finger  3843  that extends from the lever arm  3818 . Because the bridging contact  3819  is on the opposite side of the passive beams  3806 , actuation of the nozzle causes the priding contact to move upwardly, into contact with the contacts  3820 . Test circuitry can be used to confirm that actuation causes this closing of the circuit formed by the contacts  3819  and  820 . If the circuit is closed appropriately, it can generally be assumed that the nozzle is operative. 
     Exemplary Method of Assembling Components 
     An exemplary method of assembling the various above-described modular components of the printhead assembly in accordance with one embodiment of the present invention will now be described. It is to be understood that the below described method represents only one example of assembling a particular printhead assembly of the present invention, and different methods may be employed to assemble this exemplary printhead assembly or other exemplary printhead assemblies of the present invention. 
     The printhead integrated circuits  3051  and the printhead tiles  3050  are assembled as follows:
         A. The printhead integrated circuit  3051  is first prepared by forming 7680 nozzles in an upper surface thereof, which are spaced so as to be capable of printing with a resolution of 1600 dpi;   B. The fluid distribution stacks  3500  (from which the printhead tiles  3050  are formed) are constructed so as to have the three layers  3510 ,  3520  and  3530 , the channel layer  3540  and the plate  3550  made of stainless steel bonded together in a vacuum furnace into a single body via metal inter-diffusion, where the inner surface of the lower layer  3530  and the surfaces of the middle and upper layers  3520  and  3510  are etched so as to be provided with the channels and holes  3531  and  3532 ,  3521  and  3522 , and  3511  to  3513 , respectively, so as to be capable of transporting the CYMK and IR inks and fixative to the individual nozzles of the printhead integrated circuit  3051  and air to the surface of the printhead integrated circuit  3051 , as described earlier. Further, the outer surface of the lower layer  3530  is etched so as to be provided with the inlet ports  3054 ;   C. An adhesive, such as a silicone adhesive, is then applied to an upper surface of the fluid distribution stack  3500  for attaching the printhead integrated circuit  3051  and the (fine pitch) PCB  3052  in close proximity thereto;   D. The printhead integrated circuit  3051  and the PCB  3052  are picked up, pre-centred and then bonded on the upper surface of the fluid distribution stack  3500  via a pick-and-place robot;   E. This assembly is then placed in an oven whereby the adhesive is allowed to cure so as to fix the printhead integrated circuit  3051  and the PCB  3052  in place;   F. Connection between the printhead integrated circuit  3051  and the PCB  3052  is then made via a wire bonding machine, whereby a 25 micron diameter alloy, gold or aluminium wire is bonded between the bond pads on the printhead integrated circuit  3051  and conductive pads on the PCB  3052 ;   G. The wire bond area is then encapsulated in an epoxy adhesive dispensed by an automatic two-head dispenser. A high viscosity non-sump adhesive is firstly applied to draw a dam around the wire bond area, and the dam is then filled with a low viscosity adhesive to fully encapsulate the wire bond area beneath the adhesive;   H. This assembly is then placed on levelling plates in an oven and heat cured to form the epoxy encapsulant  3053 . The levelling plates ensure that no encapsulant flows from the assembly during curing; and   I. The thus-formed printhead tiles  3050  and printhead integrated circuits  3051  are ‘wet’ tested with a suitable fluid, such as pure water, to ensure reliable performance and are then dried out, where they are then ready for assembly on the fluid channel member  3040 .       

     The units composed of the printhead tiles  3050  and the printhead integrated circuits  3051  are prepared for assembly to the fluid channel members  3040  as follows:
         J. The (extended) flex PCB  3080  is prepared to provide data and power connection to the printhead integrated circuit  3051  from the PCB  3090  and busbars  3071 ,  3072  and  3073 ; and   K. The flex PCB  3080  is aligned with the PCB  3052  and attached using a hot bar soldering machine.       

     The fluid channel members  3040  and the casing  3020  are formed and assembled as follows:
         L. Individual fluid channel members  3040  are formed by injection moulding an elongate body portion  3044   a  so as to have seven individual grooves (channels) extending therethrough and the two longitudinally extending tabs  3043  extending therealong on either side thereof. The (elongate) lid portion  3044   b  is also moulded so as to be capable of enclosing the body portion  3044   a  to separate each of the channels. The body and lid portions are both moulded so as to have end portions which form the female and male end portions  3045  and  3046  when assembled together. The lid portion  3044   b  and the body portion  3044   a  are then adhered together with epoxy and cured so as to form the seven ducts  3041 ;   M. The casing  3020  is then formed by extruding aluminium to a desired configuration and length by separately forming the (elongate) support frame  3022 , with the channel  3021  formed on the upper wall  3027  thereof, and the (elongate) cover portion  3023 ;   N. The end plate  3110  is attached with screws via the threaded portions  3022   a  and  3022   b  formed in the support frame  3022  to one (first) end of the casing  3020 , and the end plate  3111  is attached with screws via the threaded portions  3022   a  and  3022   b  to the other (second) end of the casing  3020 ;   O. An epoxy is applied to the appropriate regions (i.e., so as not to cover the channels) of either a female or male connector  3047  or  3048 , and either the female or male connecting section  3049   a  or  3049   b  of a capping member  3049  via a controlled dispenser;   P. An epoxy is applied to the appropriate regions (i.e., so as not to cover the channels) of the female and male end portions  3045  and  3046  of the plurality of fluid channel members  3040  to be assembled together, end-to-end, so as to correspond to the desired length via the controlled dispenser;   Q. The female or male connector  3047  or  3048  is then attached to the male or female end portion  3046  or  3045  of the fluid channel member  3040  which is to be at the first end of the plurality of fluid channel members  3040  and the female or male connecting section  3049   a  or  3049   b  of the capping member  3049  is attached to the male or female end portion  3046  or  3045  of the fluid channel member  3040  which is to be at the second end of the plurality of fluid channel members  3040 ;   R. Each of the fluid channel members  3040  is then placed within the channel  3021  one-by-one. Firstly, the (first) fluid channel member  3040  to be at the first end is placed within the channel  3021  at the first end, and is secured in place by way of the PCB supports  3091  which are clipped into the support frame  3022 , in the manner described earlier, so that the unconnected end portion  3045  or  3046  of the fluid channel member  3040  is left exposed with the epoxy thereon. Then, a second member  3040  is placed in the channel  3021  so as to mate with the first fluid channel member  3040  via its corresponding end portion  3045  or  3046  and the epoxy therebetween and is then clipped into place with its PCB supports  3091 . This can then be repeated until the final fluid channel member  3040  is in place at the second end of the channel  3021 . Of course, only one fluid channel member  3040  may be used, in which case it may have a connector  3047  or  3048  attached to one end portion  3046  or  3045  and a capping member  3049  attached at the other end portion  3045  or  3046 ;   S. This arrangement is then placed in a compression jig, whereby a compression force is applied against the ends of the assembly to assist in sealing the connections between the individual fluid channel members  3040  and their end connector  3047  or  3048  and capping member  3049 . The complete assembly and jig is then placed in an oven at a temperature of about 100° C. for a predefined period, for example, about 45 minutes, to enhance the curing of the adhesive connections. However, other methods of curing, such as room temperature curing, could also be employed;   T. Following curing, the arrangement is pressure tested to ensure the integrity of the seal between the individual fluid channel members  3040 , the connector  3047  or  3048 , and the capping member  3049 ; and   U. The exposed upper surface of the assembly is then oxygen plasma cleaned to facilitate attachment of the individual printhead tiles  3050  thereto.       

     The printhead tiles  3050  are attached to the fluid channel members  3040  as follows:
         V. Prior to placement of the individual printhead tiles  3050  upon the upper surface of the fluid channel members  3040 , the bottom surface of the printhead tiles  3050  are argon plasma cleaned to enhance bonding. An adhesive is then applied via a robotic dispenser to the upper surface of the fluid channel members  3040  in the form of an epoxy in strategic positions on the upper surface around and symmetrically about the outlet ports  3042 . To assist in fixing the printhead tiles  3050  in place a fast acting adhesive, such as cyanoacrylate, is applied in the remaining free areas of the upper surface as the adhesive drops  3062  immediately prior to placing the printhead tiles  3050  thereon;   W. Each of the individual printhead tiles  3050  is then carefully aligned and placed on the upper surface of the fluid channel members  3040  via a pick-and-place robot, such that a continuous print surface is defined along the length of the printhead module  3030  and also to ensure that that the outlet ports  3042  of the fluid channel members  3040  align with the inlet ports  3054  of the individual printhead tiles  3050 . Following placement, the pick-and-place robot applies a pressure on the printhead tile  3050  for about 5 to 10 seconds to assist in the setting of the cyanoacrylate and to fix the printhead tile  3050  in place. This process is repeated for each printhead tile  3050 ;   X. This assembly is then placed in an oven at about 100° C. for about 45 minutes to cure the epoxy so as to form the gasket member  3060  and the locators  3061  for each printhead tile  3050  which seal the fluid connection between each of the outlet and inlet ports  3042  and  3054 . This fixes the printhead tiles  3050  in place on the fluid channel members  3040  so as to define the print surface; and   Y. Following curing, the assembly is inspected and tested to ensure correct alignment and positioning of the printhead tiles  3050 .       

     The printhead assembly  3010  is assembled as follows:
         Z. The support member  3112  is attached to the end PCB supports  3091  so as to align with the recessed portion  3091   b  of the end supports  3091 ;   AA. The connecting members  3102  are placed in the abutting recessed portions  3091   b  between the adjacent PCB supports  3091  and in the abutting recessed portions  3112   b  and  3091   b  of the support members  3112  and end PCB supports  3091 , respectively;   BB. The PCBs  3090 , each having assembled thereon a PEC integrated circuit  3100  and its associated circuitry, are then mounted on the PCB supports  3091  along the length of the casing  3020  and are retained in place between the notch portions  3096   a  of the retaining clips  3096  and the recessed portions  3093   a  and locating lugs  3093   b  of the base portions  3093  of the PCB supports  3091 . As described earlier, the PCBs  3090  can be arranged such that the PEC integrated circuit  3100  of one PCB  3090  drives the printhead integrated circuits  3051  of four printhead tiles  3050 , or of eight printhead tiles  3050 , or of 16 printhead tiles  3050 . Each of the PCBs  3090  include the connection strips  3090   a  and  3090   b  on the inner face thereof which communicate with the connecting members  3102  allowing data transfer between the PEC integrated circuits  3100  of each of the PCBs  3090 , between the printhead integrated circuits  3051  and PEC integrated circuits  3100  of each of the PCBs  3090 , and between the data connection portion  3117  of the connector arrangement  3115 ;   CC. The connector arrangement  3115 , with the power supply, data and fluid delivery connection portions  3116 ,  3117  and  3118  attached thereto, is attached to the end plate  3110  with screws so that the region  3115   c  of the connector arrangement  3115  is clipped into the clip portions  3112   d  of the support member  3112 ;   DD. The busbars  3071 ,  3072  and  3073  are inserted into the corresponding channeled recesses  3095   a ,  3095   b  and  3095   c  of the plurality of PCB supports  3091  and are connected at their ends to the corresponding contact screws  3116   a ,  3116   b  and  3116   c  of the power supply connection portion  3116  of the connector arrangement  3115 . The busbars  3071 ,  3072  and  3073  provide a path for power to be distributed throughout the printhead assembly;   EE. Each of the flex PCBs  3080  extending from each of the printhead tiles  3050  is then connected to the connectors  3098  of the corresponding PCBs  3090  by slotting the slot regions  81  into the connectors  3098 ;   FF. The pressure plates  3074  are then clipped onto the PCB supports  3091  by engaging the holes  3074   a  and the tab portions  3074   c  of the holes  3074   b  with the corresponding retaining clips  3099  and  3096  of the PCB supports  3091 , such that the raised portions  75  of the pressure plates  3074  urge the power contacts of the flex PCBs  3080  into contact with each of the busbars  3071 ,  3072  and  3073 , thereby providing a path for the transfer of power between the busbars  3071 ,  3072  and  3073 , the PCBs  3090  and the printhead integrated circuits  3051 ;   GG. The internal fluid delivery tubes  3006  are then attached to the corresponding tubular portions  3047   b  or  3048   b  of the female or male connector  3047  or  3048 ; and   HH. The elongate, aluminium cover portion  3023  of the casing  3020  is then placed over the assembly and screwed into place via screws through the remaining holes in the end plates  3110  and  3111  into the threaded portions  3023   b  of the cover portion  3023 , and the end housing  3120  is placed over the connector arrangement  3115  and screwed into place with screws into the end plate  3110  thereby completing the outer housing of the printhead assembly and so as to provide electrical and fluid communication between the printhead assembly and a printer unit. The external fluid tubes or hoses can then be assembled to supply ink and the other fluids to the channels ducts. The cover portion  3023  can also act as a heat sink for the PEC integrated circuits  3100  if the fin portions  3023   d  are provided thereon, thereby protecting the circuitry of the printhead assembly  3010 .       

     Testing of the printhead assembly occurs as follows:
         II. The thus-assembled printhead assembly  3010  is moved to a testing area and inserted into a final print test machine which is essentially a working printing unit, whereby connections from the printhead assembly  3010  to the fluid and power supplies are manually performed;   JJ. A test page is printed and analysed and appropriate adjustments are made to finalize the printhead electronics; and   KK. When passed, the print surface of the printhead assembly  3010  is capped and a plastic sealing film is applied to protect the printhead assembly  3010  until product installation.       

     While the present invention has been illustrated and described with reference to exemplary embodiments thereof, various modifications will be apparent to and might readily be made by those skilled in the art without departing from the scope and spirit of the present invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but, rather, that the claims be broadly construed.