PCT
`
`WORLD INTELLECTUAL PROPERTY ORGANIZATION
`International Bureau
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(51) International Patent Classification 7 :
`
`(11) International Publication Number:
`
`WO 00/54973
`
`B41] 2/145
`
`(43) International Publication Date:
`
`21 September 2000 (2109.00)
`
`(21) International Application Number:
`
`PCT/AU00/00184
`
`(22) International Filing Date:
`
`15 March 2000 ( 15 .O3.00)
`
`(30) Priority Data:
`PP 9222
`
`16 March 1999 (16.03.99)
`
`AU
`
`(71) Applicant (for all designated States except US): SILVER-
`BROOK RESEARCH PTY. LTD. [AU/AU]; 393 Darling
`Street, Balmain, NSW 2041 (AU).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): SILVERBROOK, Kia
`[AU/AU]; 393 Darling Street, Balmain, NSW 2041 (AU).
`KING, Tobin, Allen [AU/AU]; Unit 2, 125 Cremome Road,
`Cremome, NSW 2090 (AU).
`
`(74) Common Representative: SILVERBROOK, Kia; Silverbrook
`Research Pty. Ltd., PO. Box 207, Balmain, NSW 2041
`(AU).
`
`(81) Designated States: AE, AL, AM, AT, AU, AZ, BA, BB, BG,
`BR, BY, CA, CH, CN, CR, CU, CZ, DE, l)K, DM, DZ, EE,
`ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP,
`KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MA,
`MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU,
`SD, SE, SG, SI, SK, SL, TJ, TM, TR, Tl‘, TZ, UA, UG,
`US, UZ, VN, YU, ZA, ZW, ARIPO patent (GH, GM, KE,
`LS, MW, SD, SL, SZ, TZ, UG, ZW), Eurasian patent (AM,
`AZ, BY, KG, KZ, MD, RU, TJ, TM), European patent (AT,
`BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU,
`MC, NL, PT, SE), OAPI patent (BF, BJ, CF, CG, CI, CM,
`GA, GN, GW, ML, MR, NE, SN, TD, TG).
`
`Published
`With international search report.
`
`(54) Title: PAGEWIDTH WIDE FORMAT PRINTER
`
`(57) Abstract
`
`a printhead as-
`A pagewiclth inkjet printer including:
`sembly having an elongate pagewidth array of inkjet nozzles,
`chambers and thermal bend actuators formed using MEMS
`techniques; wherein the array extends at
`least 36 inches
`(9l4mm) in length; and,
`the printhead assemby being con-
`structed and arranged such that adequate heat dissipation oc-
`curs at equilibrium operating conditions without a forced heat
`exchange system.
`
`HP 1003
`Page 1 of 50
`
`

`
`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PCT on the front pages of pamphlets publishing international applications under the PCT.
`Albania
`ES
`LS
`Lesotho
`SI
`FI
`LT
`Armenia
`Lithuania
`SK
`FR
`Austria
`LU
`SN
`Luxembourg
`LV
`GA
`Australia
`Latvia
`SZ
`GB
`TD
`Monaco
`MC
`Azerbaijan
`MD
`GE
`TG
`Bosnia and Herzegovina
`Republic of Moldova
`Barbados
`GH
`MG
`TJ
`Madagascar
`MK
`GN
`Belgium
`The former Yugoslav
`GR
`Burkina Faso
`Republic of Macedonia
`HU
`Mali
`Bulgaria
`IE
`Benin
`Mongolia
`IL
`Brazil
`Mauritania
`Belarus
`IS
`Malawi
`IT
`Canada
`Mexico
`JP
`Central African Republic
`Niger
`KE
`Netherlands
`Congo
`Switzerland
`KG
`Norway
`KP
`Céle d’Ivoire
`New Zealand
`Poland
`Cameroon
`China
`Portugal
`Cuba
`Romania
`Russian Federation
`Czech Republic
`Sudan
`Germany
`Denmark
`Sweden
`Estonia
`Singapore
`
`Spain
`Finland
`France
`Gabon
`United Kingdom
`Georgia
`Ghana
`Guinea
`Greece
`Hungary
`Ireland
`Israel
`Iceland
`Italy
`Japan
`Kenya
`Kyrgyzstan
`Democratic People's
`Republic of Korea
`Republic of Korea
`Kazakslan
`Saint Lucia
`Liechtenstein
`Sri Lanka
`Liberia
`
`Slovenia
`Slovakia
`Senegal
`Swaziland
`Chad
`Togo
`Tajikistan
`Turkmenistan
`Turkey
`Trinidad and Tobago
`Ukraine
`Uganda
`United States of America
`Uzbekistan
`Viet Nam
`Yugoslavia
`Zimbabwe
`
`TR
`TT
`UA
`UG
`US
`UZ
`VN
`YU
`ZW
`
`ML
`MN
`MR
`MW
`MX
`NE
`NL
`NO
`NZ
`PL
`PT
`RO
`RU
`SD
`SE
`SG
`
`KR
`KZ
`LC
`LI
`LK
`LR
`
`HP 1003
`Page 2 of 50
`
`

`
`wo 00/54973
`
`PCT/AU00/00184
`
`TITLE:
`
`PAGEWIDTH WIDE FORMAT PRINTER
`
`FIELD OF THE INVENTION
`
`The present
`
`invention relates to printers and in particular digital
`
`inkjet
`
`printers for wide format printing.
`
`BACKGROUND OF THE INVENTION
`
`Wide format pagewidth printers are well known with various models
`
`commercially available, for example, the HP 35 OOCP printer from Hewlett-Packard.
`
`Unfortunately,
`
`this printer and other similar wide format printers are
`
`excessively slow as the printhead prints in a series of transverse swathes across the
`
`page.
`
`To overcome this, there have been attempts to design printers that can print
`
`the entire width of the page simultaneously. A pagewidth printhead does not traverse
`
`back and forth across the page and thereby significantly increases printing speeds.
`
`However, proposals
`
`for
`
`a pagewidth printhead assembly have not become
`
`commercially successful because of the functional limitations imposed by standard
`
`printhead technology. A 600 dpi thermal bubble jet printhead configured to extend the
`entire width of a 54 inch wide standard roll of paper would require 136,000 inkjet
`
`nozzles and would generate 24 kilowatts of heat during operation. This is roughly
`
`equivalent to the heat produced by 24 domestic bar heaters and would need to be
`
`actively cooled using a heat exchange system such as forced air or water cooling. This
`
`is impractical for most domestic and commercial environments as the cooling system
`
`for the printer would probably require some type of external venting. Without external
`
`venting, the room in which the printer is situated is likely to get over heated.
`
`HP 1003
`Page 3 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`_ 2 _
`
`The power consumption problem also influences the size of the printhead
`
`required for pagewidth wide format printing. The distance between thermal inkjet
`
`nozzles cannot be less than a minimum spacing in case the heat generated to fire ink
`
`from one nozzle inadvertently fires the ink from an adjacent nozzle. A similar
`
`problem applies to piezo—electric inkjet printheads. The piezo-electric material has a
`
`small size change per volt applied; typically about 3 x 1O'6m per volt. Even if this size
`
`change is optimised using a bend actuator mechanism, the physical dimensions of the
`
`piezo-electric material required to produce the size change necessary to eject ink from
`
`a nozzle will only allow a printhead construction with one nozzle per 1 to 4mmZ.
`
`In light of the low nozzle packing densities permitted by the standard inkjet
`
`technologies, the size of the printhead required for full color wide format pagewidth
`
`printing becomes impractical.
`
`Another obstacle to the commercial manufacturer of pagewidth printheads is
`
`the cost. These printheads are formed using Micro—Electro—Mechanical Systems
`
`(MEMS) techniques that are similar to the manufacture of silicon computer chips.
`
`In
`
`this process, the ink nozzles and ejector mechanisms are formed in a series of etching
`
`and deposition procedures on silicon wafers as is the case with other computer chips.
`
`The cost of printhead chips is roughly proportional to the area of the wafer
`
`required, however, the cost of the printhead does increase disproportionately with an
`
`increasing area of wafer used. This is because manufacturing costs begins to escalate
`
`as the chip defect rate also increases with wafer size. Faults will inevitably occur
`
`during silicon chip manufacture and some level of attrition is always present because
`
`of this. A single chip will render an entire pagewidth printhead chip defective as is the
`
`case with regular silicon chip production. However, because the pagewidth chip is
`
`HP 1003
`Page 4 of 50
`
`

`
`W0 00/54973
`
`PCT/AU00/00184
`
`_ 3 -
`
`larger than regular chips, there is a higher probability that any particular chip will be
`
`defective thereby raising the defect rate as a whole in comparison to regular silicon
`
`chip production. The problem is further exacerbated when much larger pagewidth
`
`chips are manufactured for wide format printing.
`
`SUMMARY OF THE INVENTION
`
`According to a first aspect, the present invention provides a pagewidth inkjet
`
`printer including:
`
`a printhead assembly having an elongate pagewidth array of inkjet nozzles,
`
`chambers and thermal bend actuators formed using MEMS techniques;
`
`the printhead assembly being constructed and arranged such that adequate
`
`heat dissipation occurs at equilibrium operating conditions without the use of a forced
`
`heat exchanged system.
`
`Preferably,
`
`the printhead assembly dissipates the majority of the heat
`
`produced during the operation of the inkjet nozzles, chambers and actuators is
`
`dissipated by the ink ejected from the nozzles.
`
`In a further preferred form,
`
`the
`
`printhead assembly has a plurality of inkjet printhead modules arranged end to end to
`
`form the array, each module having a printhead chip in which the nozzles, chambers
`
`and actuators are formed wherein the surface area of the chip required for each nozzle
`2
`is less than 0.5mm .
`
`In a particularly preferred form, the surface area of the chip
`
`required for each nozzle is less than O.lmm2 and may conveniently be less than
`
`0.02mm2.
`
`According to a second aspect, the present invention provides a pagewidth
`
`inkjet printer including:
`
`HP 1003
`Page 5 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`- 4 -
`
`a printhead assembly having an elongate pagewidth array of inkjet nozzles,
`
`chambers and thermal bend actuators formed using MEMS techniques;
`
`wherein the array extends at least 36 inches (9l4mm) in length; and,
`
`the nozzles, chambers and actuators are formed in one or more printhead
`
`chips such that the surface area of the chip required for each nozzle is less than
`
`0.5mm2.
`
`According to another aspect,
`
`the present invention provides a pagewidth
`
`inkjet printer including:
`
`a printhead assembly having an elongate pagewidth array of inkjet nozzles,
`
`chambers and thermal bend actuators formed using MEMS techniques;
`
`wherein the array extends at least 36 inches (800mm) in length; and,
`
`the printhead assembly has a plurality of inkjet printhead modules arranged
`
`end to end to form the array.
`
`ln a particularly preferred form, the printhead assembly further includes a
`
`plurality of printhead units, each unit having a plurality of the printhead modules
`
`mounted thereon such that the printhead units are in turn mounted to the printhead
`
`assembly to form the array.
`
`In some embodiments, 70 printhead modules are abutted
`
`in an overlapping format
`
`to provide a printhead assembly extending 54 inches
`
`(l372mm).
`
`It will be appreciated that by overlapping adjacent printhead modules, the
`
`printing produced by each module can be electronically adjusted to precisely abut the
`
`printing from modules on either side.
`
`It will be appreciated that by mounting a number of printhead modules on a
`
`printhead unit and then using a number of printhead units to form the printhead
`
`HP 1003
`Page 6 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`_ 5 _
`
`assembly, there are two levels of modularity in the design which permit defective
`
`components to be removed and replaced conveniently and relatively inexpensively.
`
`It has been found that pagewidth printers incorporating printhead chips using
`
`thermal bend actuators can produce a high resolution print while consuming
`
`significantly less power. A 54 inch wide format pagewidth printhead formed in
`
`accordance with standard thermal
`
`inkjet technology would provide 136,000 inkjet
`
`nozzles to produce a resolution of 600 dpi. It could print 150 foot long roll of standard
`
`54 inch wide paper in approximately 2.4 minutes, however, it will require 24 kilowatts
`
`of power of which approximately 20 kilowatts would need to be dissipated by forced
`
`air, water or other coolant.
`
`A printer according to the present invention would also print the standard 150
`
`foot length of a 54 inch wide roll in 2.4 minutes, however by using 364,000 nozzles it
`
`provides 1600 dpi resolution (generally accepted as photographic quality) and would
`
`consume only 0.655 kilowatts which would not require any additional cooling. With
`
`this level of power consumption, the ejection of ink would dissipate sufficient heat.
`
`This allows a greater nozzle packing density and reduces the overall size of the
`
`printhead assembly.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Notwithstanding any other forms which may fall within the scope of the
`
`present invention, a preferred form denoted as the Macroprint product will now be
`
`described by way of example only with reference to the accompanying drawings in
`
`which:
`
`Figure l is a front perspective view of the printer with media on the feed and
`
`take up spools;
`
`HP 1003
`Page 7 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`- 6 -
`
`Figure 2 is a front perspective View of the printer without media on the
`
`spools;
`
`Figure 3 shows a rear perspective View of the printer with media on the feed
`
`and take up spools;
`
`Figure 4 is a front elevation of the printer without media on the feed or take
`
`up spools;
`
`Figure 5 is a plan view;
`
`Figure 6 is a rear elevation without media on the feed or take up spools;
`
`Figure 7 is a right end elevation;
`
`Figure 8 is a left end elevation;
`
`Figure 9 is a front perspective view of the printer with the top lid open
`
`exposing the ink cartridges;
`
`Figure 10 is a front perspective view of the printer showing the front panel
`
`removed to expose the printhead units;
`
`Figure 11 is an enlarged portion of figure 10;
`
`Figure 12 is a partial cross sectional view of section A-A of figure 4;
`
`Figure 13 is an enlarged portion of figure 12;
`
`Figure 14 is a perspective view showing the leg access cover removed;
`
`Figure 15 is an underside perspective View of a single printhead unit in
`
`isolation with 10 attached printhead modules;
`
`Figure 16 is a top—side perspective view of a single printhead unit in isolation;
`
`Figure 17 is a perspective view of 7 printhead units mounted end to end on a
`
`floating support metalwork chassis;
`
`Figure 18 is an underside perspective view of the printhead units of figure 17;
`
`HP 1003
`Page 8 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`-7-
`
`Figure 19 is a perspective view of a single printhead unit and part of the
`
`printer ink supply system;
`
`Figure 20 is a perspective view of the printhead assembly together with the
`
`ink cartridges and ink reservoirs of the ink supply system;
`
`Figure 21 is a partial cross sectional view showing the fluid communication
`
`between an ink cartridge and an ink reservoir;
`
`Figure 22 is a rear perspective view of the printer electrical system;
`
`Figure 23 is a front perspective view of the printer electrical system;
`
`Figure 24 is an enlarged portion of figure 22 showing the main printed circuit
`
`Figure 25a is a perspective View of the media cutter;
`
`Figure 25b is an enlarged portion of figure 25a showing the rotating knife
`
`wheel and motor of the media cutter;
`
`Figure 26 is a top-side perspective view showing the media path through the
`
`printer; and
`
`Figure 27 is a rear perspective view showing the media path through the
`
`printer.
`
`REFERENCE NUMERALS IN DRAWINGS
`
`printhead modules
`
`printhead chip
`
`printhead unit
`
`ink connectors
`
`metal nozzle shield
`
`ink cartridges
`
`HP 1003
`Page 9 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`sprung capping assembly
`
`metal chassis
`
`exit spike wheels
`
`primary feed roller
`
`media entry point
`
`motor driven pinch rollers
`
`secondary media feed roller
`
`media exit point
`
`PCB’s
`
`DRAM
`
`USB2 connector
`
`controller chip
`
`ribbon cable
`
`USB2 cables
`
`main PCB
`
`metal platen
`
`powered cam shaft
`
`motor and gearbox
`
`ink reservoirs
`
`reservoir sensors
`
`ink cartridge exit nozzle
`
`foil bladder
`
`ink outlet molding
`
`sprung rubber coated ball bearing
`
`HP 1003
`Page 10 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`ink inlet assembly
`
`sprung collar
`
`hydrophobic seal
`
`pin
`
`ink
`
`metal trough
`
`retaining clips
`
`retaining clip recesses
`
`feed spool
`
`media
`
`take up spool
`
`spaced legs
`
`motor and gear box assemblies
`
`brushes
`
`traverser block and paper sensor
`
`shaft
`
`belt drive
`
`pivoting arm
`
`rotating knife wheel
`
`metal spring
`
`sensor leads
`
`metal U channel
`
`cheek molding
`
`sprung tensioner device
`
`HP 1003
`Page 11 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`main printer housing
`
`color LCD and touch screen
`
`emergency stop button
`
`base structures
`
`wind down feet
`
`paper tray
`
`date connectors
`
`mains power input
`
`left end molding
`
`right end molding
`
`lid
`
`handle
`
`busbars
`
`front panel
`
`castors
`
`alternative media entry rollers
`
`DESCRIPTION OF A PREFERRED EMBODIMENT
`
`The preferred embodiment, known as Macroprint, is a wide format printer
`
`that prints 1600 dpi photographic quality prints up to 54 inches wide.
`
`Intended
`
`markets include photographic bureaus, CAD bureaus, advertising agencies, corporate
`
`and educational applications. The product accommodates standard media sizes and
`
`types from A4 sheets to rolls 54 inches wide by 150 feet in length. The main feature
`
`of Macroprint is its print speed: typically 600 times faster than comparable machines.
`
`HP 1003
`Page 12 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`_ 11 -
`
`The product is simple in operation and has been designed with powder coated
`
`metal panels and standard extrusions to minimise expensive and complicated
`
`assemblies and numerous moldings. Referring to figures 1
`
`to 8, the main printer
`
`housing 56 is supported between spaced legs 43. An intuitive user interface on a LCD
`
`color touch screen 57 welcomes the user and initialises the machine from stand by
`
`mode. For the user’s convenience, a large emergency stop button 58 is provided
`
`directly beneath the touch screen 57.
`
`Referring to figures 7 and 8, the legs 43 are secured to base structures 59
`
`which include castors 70 for mobility and wind down feet 60 for stability. A paper
`
`tray 61 extends between the base structures 59 to collect single printed sheets.
`
`One of the legs 43 is provided with data connectors 62 and a mains power
`
`input 63. The legs 43 support the main printer housing 56 at left and right end
`
`moldings 64 and 65 respectively. The top of the printer housing includes a lid 66
`
`which may be opened using handle 67 to replace ink cartridges 6 shown in figure 9.
`
`The front of the main housing 56 has a front panel 69 which may be removed to
`
`further expose the printhead assembly as shown in figure 10.
`
`As best shown in figures 15, 16, 17 and 18, Macroprint uses a full width array
`
`of 70 printhead modules 1 mounted end to end at a small angle to the media feed
`
`direction to potentially provide a slight overlap between the printing of adjacent
`
`modules. The printing from each module 1
`
`is aligned after installation such that it
`
`precisely abuts the printing of adjacent modules. Each module 1 has a printhead chip
`
`2 constructed using MEMS (Micro-Electro—Mechanical Systems) techniques to form
`
`the ink nozzles, chambers and actuators. The particular printhead chips used by
`
`Macroprint are called MEMJET chips.
`
`These chips are fully described in the
`
`HP 1003
`Page 13 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`- 12 _
`
`Applicant’s United States Application entitled “A Method of Manufacturing a
`
`Thermal Bend Actuator” (Docket No. MJ07), the contents of which are specifically
`
`incorporated by cross
`
`reference.
`
`Further,
`
`the construction of the preferred
`
`embodiment is along similar lines to that formed in Australian Provisional Patent
`
`Application No. PQ4559, filed 9 December, 1999, entitled “Memjet Four Color
`
`Modular Printhead Packaging “(Docket No. MJ57), and Australian Provisional Patent
`
`Application No. PQ5959, filed 2 March, 2000, entitled “Modular Printhead” (Docket
`
`No. MI22). The contents of both these applications are also specifically incorporated
`
`by cross reference.
`
`MEMJET chips have 5280 nozzles, each with its own mechanical ink droplet
`
`ejection mechanism. MEMJET chips using cyan, magenta, yellow and black (CMYK)
`
`ink provide a printhead with 1600 nozzles per inch for each color. This produces
`
`color printing at an image resolution of 1600 dpi which is sufficient for photographic
`
`image quality.
`
`As shown in figures 15, 16 and 17, ten printhead modules 1 are mounted to a
`
`modular printhead unit 3 denoted as a MEMJET printhead unit. Seven printhead units
`
`3 are abutted together along a metal chassis (fig. 17), to provide a 54 inch print width.
`
`The busbars 68 provide positive and negative current to the printhead units 3 via spade
`
`terminals.
`
`It is possible to make wider format printers but 54 inches is a large standard
`
`roll size. The modular design of the printhead assembly allows individual printhead
`
`modules 1 to be accessed for replacement if necessary.
`
`It will be appreciated that this
`
`is far more convenient and cost effective than the replacement of an entire printhead
`
`assembly or even a single MEMJET printhead unit 3. As best shown in figure 20, the
`
`HP 1003
`Page 14 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`- 13 _
`
`MEMJET printhead units 3 are daisy-chained together with ink connectors 4 so four
`
`colors can be transmitted to the entire length of the printhead assembly.
`
`Other design configurations of the printhead assembly can be accommodated
`
`to provide printhead chips that supply fixer, infrared inks and/or specialist metallic
`
`inks together with the CMYK inks. Other design configurations include an air
`
`chamber and pump (not shown) added to the MEMJET printhead units 3 which supply
`
`positive pressure through the metal nozzle shield 5 to eliminate ingress of foreign
`
`particles. The ink cartridges 6 may also include a micro air filter (not shown) for use
`
`with a micro pump (not shown) and sprung capping assembly 7.
`
`The MEMJET printhead units 3 are heat staked/secured to a metal chassis 8
`
`that carries exit spike wheels 9. As best shown in figures 12 and 13, the spike wheels
`
`9 oppose the primary media feed roller 10 to feed the media out of the printhead
`
`assembly at 14. Moveable pinch rollers 12 oppose the secondary media feed roller 13.
`
`Media is drawn in at 11 by the action of the primary roller 10 acting against a passive
`
`spring roller and feeding the media to the secondary roller 13. The chassis 8 is sprung
`
`and automatically moves the MEMJET printhead units 3 away from the metal platen
`
`23 to accommodate thicker print media.
`
`The upper surface of the chassis 8
`
`accommodates the control printed circuit boards (PCBS) 15 for each MEMJET
`
`printhead unit 3. Each PCB 15 has up to 512 megabytes of DRAM 16, a double USB
`
`2' connector 17, a controller chip 18 and a printhead module interface connector. A
`
`ribbon cable 19 connects the PCBs 15 to the printhead modules 1 and each PCB 15 is
`
`daisy-chain connected via USB 2 cables 20 to a main PCB 21 located in a printer leg
`
`43.
`
`HP 1003
`Page 15 of 50
`
`

`
`wo oo/54973
`
`PCT/AU00/00184
`
`- 14 -
`
`The MEMJET chips 2 are capped by the capping assembly 7 when not in use.
`
`The capping assembly has a full width moving metal platen with an elastomeric (or
`
`similar) seal. The metal platen is spring mounted and moved into position by the
`
`action of powered cam shaft 24. The cam shaft 24 also moves the array of MEMJET
`
`printhead units 3 clear when loading media. The cam shaft is driven by the cam shaft
`
`motor and gearbox 25 as best shown in figure 22.
`
`Referring to figure 19, the ink supply system is shown without the supporting
`
`metalwork. The entire array of MEMJET printhead units 3 is supplied with CMYK
`
`inks from four individual reservoirs 26 mounted above them. These reservoirs are
`
`supplied by replaceable ink cartridges 6 which sit at the top of the printer under the
`
`hinged lid 66. The cartridges 6 plugged directly into the ink reservoirs 26 via exit
`
`nozzle 28. The ink reservoirs 26 have sensors 27 that monitor ink levels.
`
`Figure 21 shows the ink cartridge exit nozzle 28 in detail. The cartridge 6 has
`
`a foil bladder 29 that is sealed around an ink outlet molding 30. A sprung rubber
`
`coated ball bearing 31 provides the seal for the ink cartridge 6. The exit nozzle 28
`
`interfaces with the ink inlet assembly 32 of the reservoir 26. This consists of a sprung
`
`collar 33 with a hydrophobic seal 34 that moves over a hollow metal pin 35. As the
`
`collar 33 moves down the pin, 35 penetrates the ink outlet molding 30 and moves the
`
`ball bearing 31, allowing ink 36 to flow.
`
`The ink cartridge 6 is a simple cardboard or thin plastic forming and, as best
`
`shown in figures 13 and 20, the cartridges are snap locked to a metal trough 37 via
`
`retaining clips 38 and corresponding recesses 39. The ink reservoirs 26 are mounted
`
`to the underside of the trough 37. The cartridges 6 hold approximately 800 millilitres
`
`HP 1003
`Page 16 of 50
`
`

`
`W0 00/54973
`
`PCT/AU00/00184
`
`- 15 -
`
`of ink and have a QA chip (not shown) which interfaces with the sensors 27 in the ink
`
`reservoirs 26.
`
`Figures 1, 3, 12, 13, 26 and 27 show the media path through the Macroprint
`
`printer. The printer accommodates a standard 54 inch print media roll which is wound
`
`onto a plastic feed spool 40. The media 41 is fed from the feed spool 40 through the
`
`printhead assembly to a take up spool 42. The feed and take up spools 40 and 42
`
`extend between the printer legs 43 and are driven by motor and gearbox assemblies 44
`
`shown in figures 22 and 23. Alternatively, a larger diameter roll of media may be used
`
`with Marcroprint because of the high operational print speeds. The larger roll may be
`
`on a separate support, such as a standard digital unwinder widely used in the print
`
`industry, and fed directly into Macroprint from the rear using alternative media entry
`
`rollers 71.
`
`The media 41 is initially fed through a convolute path by the powered
`
`primary and secondary rollers 10 and 13. During loading of the media, the sheet is fed
`
`between the primary roller 10 and the spring passive roller (figs 13 and 27). The
`
`primary roller 10 pushes the media 41 towards the secondary roller 13 while the pinch
`
`rollers 12 pivot away from the secondary roller 13 so that the media 41 can be guided
`
`around the curve of the roller by brushes 45. When the media 41 reaches the apex of
`
`the secondary roller 13, the pinch rollers 12 pivot down and provide positive grip for
`
`further feeding. The media 41 passes over the full width metal platen 23, between the
`
`MEMJET printhead units 3 and the capping assembly 7, and exits over two sets of
`
`passive rollers to the take—up reel 42.
`
`Referring to figures 25a and 25b, the printer is provided with a media cutter
`
`assembly.
`
`it consists of a traverser block and paper sensor 46 that runs on a shaft 47
`
`HP 1003
`Page 17 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`- 16 _
`
`under the action of belt drive 48. A pivoting metal arm 49 supports a rotating knife
`
`wheel 50 that cuts the media 41. The arm 49 is positioned up or down by use of the
`
`metal spring 51 contacting stops (not shown) on each cheek molding 54 of the printer.
`
`If the media 41 is inadvertently pulled, the cutter 50 and traverser block 46 pivots clear
`
`around the shaft 47 to prevent damage. Sensor leads 52 from the image sensor 46 run
`
`in a metal U channel 53 and connect to the main PCB 21 in the printer leg. A sprung
`
`tensioner device 55 is mounted on the left side of the printer to complete the cutter
`
`assembly.
`
`The 1600 dpi high resolution of the Macroprint allows economy of ink usage
`
`and image quality to be superior to any contemporary products.
`
`The MEMJET
`
`printhead units 3 use 1 picoliter of ink per 1600 dpi nozzle as opposed to a current
`
`average of2l picoliters per 600 dpi nozzle. The ratio of ink usage of a current 600 dpi
`
`nozzle compared to a MEMJET 1600 dpi nozzle is 2.95:1.
`
`The Macroprint printer can print an Al sized sheet of media at 1600 dpi
`
`photo quality in 2 seconds. This makes it about 600 times faster than the top of the
`
`range HP 3500 CP printer. The 54 inch wide by 150 foot length standard roll of paper
`
`can be printed in 2.4 minutes compared to 24 hours for the HP 3500 CP printer.
`
`It is
`
`theoretically possible to produce a thennal bubble inkjet printhead that extends the
`
`entire 54 inch width of a standard roll to achieve the same print speeds, however, its
`
`power consumption would be approximately 40 times greater than Macroprint.
`
`Accordingly, it would require an additional active cooling system to dissipate heat.
`
`Even with most forced heat exchange systems, the nozzle packing density would not
`
`be high enough to provide a wide format pagewidth printhead of a practical size.
`
`Because of these impediments, pagewidth thermal bubble inkjet printers have not
`
`HP 1003
`Page 18 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`-17-
`
`become a commercial reality. By utilising thermal bend actuators in the MEMS
`
`printhead chips and modularising the printhead assembly design,
`
`the Macroprint
`
`printer provides practical wide format printing in a real commercial sense.
`
`The present invention has been described herein with reference a specific
`
`example which should not be seen as limiting or restrictive on the broad inventive
`
`concept.
`
`HP 1003
`Page 19 of 50
`
`

`
`W0 00/54973
`
`PCT/AU00/00184
`
`CLAIMS:—
`
`l.
`
`A pagewidth inkjet printer including:
`
`a printhead assembly having an elongate pagewidth array of inkjet nozzles,
`
`chambers and thermal bend actuators formed using MEMS techniques;
`
`wherein the array extends at least 36 inches (9l4mm) in length; and,
`
`the printhead assembly being constructed and arranged such that adequate
`
`heat dissipation occurs at equilibrium operating conditions without a forced heat
`
`exchange system.
`
`2.
`
`A pagewidth inkjet printer according to claim 1, wherein the majority
`
`of heat generated by the thermal bend actuators is dissipated by ink ejected through the
`
`nozzles.
`
`3.
`
`A pagewidth inkjet printer according to claim 1, wherein the printhead
`
`assembly has a plurality of inkjet printhead modules arranged end to end to form the
`
`array, each module having a printhead chip in which the nozzles, chambers and
`
`thermal bend actuators are formed such that the surface area of the chip required for
`
`each nozzles is less than 0.5mm2.
`
`4.
`
`A pagewidth inkjet printer according to claim 3, wherein the surface
`
`area of the chip required for each nozzle is less than 0.1mn12.
`
`5.
`
`A pagewidth inkjet printer according to claim 4, wherein the surface
`
`area of the chip required for each nozzle is less than O.02mm2.
`
`6.
`
`A pagewidth inkjet printer including a printhead assembly having an
`
`elongate pagewidth array of inkjet nozzles, chambers and thermal bend actuators
`
`formed using MEMS techniques, wherein the array extends at
`
`least 36 inches
`
`(914m) in length; and,
`
`HP 1003
`Page 20 of 50
`
`

`
`W0 00/54973
`
`PCT/AU00/00184
`
`_ 19 _
`
`the nozzles, chambers and thermal bend actuators are formed in one or more
`
`printhead chips such that;
`
`the surface area of the chip required for each nozzle is less than 0.5mm2.
`
`7.
`
`A pagewidth inkjet printer according to claim 6, wherein the surface
`
`area of the chip required for each nozzle is less than 0.1mm2.
`
`8.
`
`A pagewidth inkjet printer according to claim 6, wherein the surface
`
`area of the chip required for each nozzle is less than O.02mm2.
`
`9.
`
`A pagewidth inkjet printer including:
`
`a printhead assembly having an elongate pagewidth array of inkjet nozzles,
`
`chambers and thermal bend actuators formed using MEMS techniques, wherein the
`
`array extends at least 36 inches (9l4mm) in length; and,
`
`the printhead assembly has a plurality of inkjet printhead modules arranged _
`
`end to end to form the array.
`
`10. A pagewidth inkjet printer according to claim 9, wherein the printhead
`
`assembly further includes a plurality of printhead units, each having a plurality of the
`
`printhead modules mounted thereon.
`
`HP 1003
`Page 21 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 22 of 50
`
`

`
`HP 1003
`Page 23 of 50
`
`

`
`HP 1003
`Page 24 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 25 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 26 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 27 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`56
`
`/X/
`
`HP 1003
`Page 28 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`56
`v\
`
`HP 1003
`Page 29 of 50
`
`

`
`WO 00/54973
`
`48MM00UMTCP
`
`HP 1003
`Page 30 of 50
`
`

`
`WO 00/54973
`
`4810M00UMTCP
`
`HP 1003
`Page 31 of 50
`
`

`
`WO 00/54973
`
`4810N00UAlTCP
`
`HP 1003
`Page 32 of 50
`
`

`
`HP 1003
`Page 33 of 50
`
`

`
`WO 00/54973
`
`4810N00UMT.CP
`
`HP 1003
`Page 34 of 50
`
`

`
`WO 00/54973
`
`4810N0OUMTCP
`
`HP 1003
`Page 35 of 50
`
`

`
`HP 1003
`Page 36 of 50
`
`

`
`HP 1003
`Page 37 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 38 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 39 of 50
`
`

`
`HP 1003
`Page 40 of 50
`
`

`
`WO 00/54973
`
`4oo10N00UAlTCD1
`
`HP 1003
`Page 41 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`..e\\\‘.~w.\\\\\)}/
`
`A
`
`%
`
`/
`
`/
`
`I\\\\\\\\k\\\\\\\
`
`50
`
`52
`
`s\\\\\\\\\\\\\\\
`‘
`§_%
`..
`§.
`%.
`\
`V
`
`\ §
`
`IZIZIZIZIZIIIZ
`
`IIIIZIIIZIIIZI
`
`57
`/AV‘
`‘\\\\\\\\\\\\'.\\\\‘
`-I'1_‘II
`
`26
`54
`
`.;‘i iF’
`
`.
`/4,. _
`
`II
`
`HP 1003
`Page 42 of 50
`
`

`
`WO 00/54973
`
`4810N00UAlTCP
`
`I.“:."\Iuu|.\u“I,a7”‘\\kl::_.l.I
`
`I,“I
`3.\
`
`D
`
`5|
`
`x
`
`,,,,1
` u_..
`
`
`/
`
`HP 1003
`Page 43 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 44 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 45 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`HP 1003
`Page 46 of 50
`
`

`
`WO 00/54973
`
`PCT/AU00/00184
`
`' .N\,_‘,_
`.
`.
`
`—-——
`
`xs ‘*
`
`. XL. - . _ _ ,
`\‘-“D‘-‘;j ,j ,1
`"’*‘~ "7:
`e,\';- '. 1.-‘.31-W_\‘-3)'—3‘.‘=i‘f-*3‘-3)‘:~_~Tm 5
`\\
`\17‘v‘rVwwr*" v
`v
`
`HP 1003
`Page 47 of 50
`
`

`
`WO 00/54973
`
`4810M00UMT.CD..
`
`HP 1003
`Page 48 of 50
`
`

`