EP0953456A1

EP0953456A1 - Integrated reciprocating cartridge architecture with integral bearings

Info

Publication number: EP0953456A1
Application number: EP99303085A
Authority: EP
Inventors: Jason Quintana; Jefferson P. Ward; David M. Wetchler
Original assignee: Hewlett Packard Co
Current assignee: HP Inc
Priority date: 1998-04-29
Filing date: 1999-04-21
Publication date: 1999-11-03
Also published as: JP2000001019A

Abstract

A hardcopy mechanism (20; 20'; 20"), such as an inkjet printing mechanism, a scanning mechanism, or a multi-function mechanism having both scanning and printing capabilities, has a reciprocating head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222) which is shuttled back and forth across a sheet of media (27). An inkjet printhead (44, 46; 70, 72, 74, 76; 80, 82, 84, 86) is shuttled over a print media (27) for printing, while a scan head (222) is shuttled across a printed sheet to read a previously printed image. This reciprocating head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222) uses a new integrated reciprocating cartridge architecture (78; 156; 176; 220) having guide rod bearings (138, 140; 142; 142'; 138", 140"; 138"', 140"') integrally formed on the cartridge, virtually eliminating the earlier separate carriage which housed guide rod bearings and held replaceable cartridges. Reciprocating cartridges, both inkjet cartridges and scanning cartridges (220), are provided for such hardcopy mechanisms, with inkjet cartridges being provided as replaceable cartridges (40, 42), snapper-type cartridges (90, 92, 94, 96), and off-axis cartridges (50, 52, 54, 56).

Description

Field of the Invention

This invention relates generally to hardcopy mechanisms, including inkjet printing mechanisms and scanning mechanisms, as well as multi-function mechanisms having both scanning and printing capabilities, where a reciprocating head is shuttled back and forth across a sheet of media. An inkjet printhead is shuttled over a print media for printing, while a scan head is shuttled across a printed sheet to read a previously printed image. More particularly, this invention relates to a new integrated reciprocating cartridge architecture having guide rod bearings integrally formed on the cartridge, virtually eliminating the earlier separate carriage which housed guide rod bearings and held replaceable cartridges.

Background of the Invention

Inkjet printing mechanisms use pens which shoot drops of liquid colorant, referred to generally herein as "ink," onto a page. Each pen has a printhead formed with very small nozzles through which the ink drops are fired. To print an image, the printhead is propelled back and forth across the page, shooting drops of ink in a desired pattern as it moves. The particular ink ejection mechanism within the printhead may take on a variety of different forms known to those skilled in the art, such as those using piezo-electric or thermal printhead technology. For instance, two earlier thermal ink ejection mechanisms are shown in U.S. Patent Nos. 5,278,584 and 4,683,481, both assigned to the present assignee, Hewlett-Packard Company. In a thermal system, a barrier layer containing ink channels and vaporization chambers is located between a nozzle orifice plate and a substrate layer. This substrate layer typically contains linear arrays of heater elements, such as resistors, which are energized to heat ink within the vaporization chambers. Upon heating, an ink droplet is ejected from a nozzle associated with the energized resistor. By selectively energizing the resistors as the printhead moves across the page, the ink is expelled in a pattern on the print media to form a desired image (e.g., picture, chart or text).
To clean and protect the printhead, typically a "service station" mechanism is mounted within the printer chassis so the printhead can be moved over the station for maintenance. For storage, or during non-printing periods, the service stations usually include a capping system which humidically seals the printhead nozzles from contaminants and drying. Some caps are also designed to facilitate priming, such as by being connected to a pumping unit that draws a vacuum on the printhead. During operation, clogs in the printhead are periodically cleared by firing a number of drops of ink through each of the nozzles in a process known as "spitting," with the waste ink being collected in a "spittoon" reservoir portion of the service station. After spitting, uncapping, or occasionally during printing, most service stations have an elastomeric wiper that wipes the printhead surface to remove ink residue, as well as any paper dust or other debris that has collected on the printhead.
To improve the clarity and contrast of the printed image, recent research has focused on improving the ink itself. To provide quicker, more waterfast printing with darker blacks and more vivid colors, pigment-based inks have been developed. These pigment-based inks have a higher solid content than the earlier dye-based inks, which results in a higher optical density for the new inks. Both types of ink dry quickly, which allows inkjet printing mechanisms to form high quality images on readily available and economical plain paper, as well as on recently developed specialty coated papers, transparencies, fabric and other media.
As the inkjet industry investigates new printhead designs, one trend is toward using a "snapper" reservoir system where permanent or semi-permanent printheads are used and a reservoir carrying a fresh ink supply is snapped into place on the printhead. Another new design uses permanent or semi-permanent printheads in what is known in the industry as an "off-axis" printer. In an off-axis system, the printheads carry only a small ink supply across the printzone, with this supply being replenished through tubing that delivers ink from an "off-axis" stationary reservoir placed at a remote stationary location within the printer. Narrower printheads may lead to a narrower printing mechanism, which has a smaller "footprint," so less desktop space is needed to house the printing mechanism during use. Narrower printheads are usually smaller and lighter, so smaller carriages, bearings, and drive motors may be used, leading to a more economical printing unit for consumers.
These snapper and off-axis inkjet systems are described in contrast with what is known as a "replaceable cartridge" system, which supply a disposable printhead with the ink supply in an inkjet cartridge, so when the reservoir is emptied, the entire cartridge including the printhead is replaced. A replaceable cartridge system assures the customer has a fresh, new printhead each time the ink supply is replaced. Some replaceable cartridges are monochrome (single color), for instance, carrying only black ink, while other cartridges are multi-color, typically carrying cyan, magenta and yellow inks. Some printing mechanisms use four monochrome cartridges, while others use a black monochrome cartridge in combination with a tri-color cartridge.
One earlier printer employs four discrete replaceable pens that carry black, cyan, magenta and yellow inks. The carriage structure for aligning these four pens has six datums that match associated datums on each pen. The datums required to control the pen registration are in the following three orthogonal directions:
1. A printhead scanning direction (X axis),
2. A paper advance direction (Y axis), and
3. An upright direction (Z axis).
To maintain proper pen alignment, the earlier four-pen printer design required both the pens and the carriage to have very close tolerances, which unfortunately, could not be obtained using economical molded parts. Instead, all of the carriage datums had to be machined, and for each pen, three of the six datums required machining. These secondary machining operations are labor intensive and costly, as opposed to merely molding a datum. The carriage located the pens against the X datums using an X-biasing spring and a flexure member with an insert molded cam that applied the necessary force against the clamping surface of the pen to seat it securely against the X, Y, and Z datums. Unfortunately, these X-biasing springs required costly heat treating and plating, to obtain the desired performance levels. This carriage used the electrical interconnect mechanism, which primarily communicates the firing signals from the carriage to the pens, to supply the force necessary to seat the pens securely against one of the Y axis datums. The clamping system required an operator to push and rotate each pen until it snapped into place, often resulting in uneven or lateral forces being applied to the pens during insertion. Unfortunately, these installation difficulties can prevent the pen datums from properly seating on their corresponding carriage datums, leading to degraded print quality because the nozzles were no longer aligned with respect to the other pens in the carriage.
In a two pen system, employing a black pen and a tri-color pen, the carriage must provide precise and repeatable positioning of the pens relative to each other and to the entire printing system. Accurate positioning of the pens is one of the primary variables to control the registration of the ink dots on the paper, which directly affects print quality. One system that was first commercially available in the DeskJet 850C and 855C models of color inkjet printers, manufactured by the Hewlett-Packard Company, the present assignee, aligned both pens to each side of a common wall using a cammed clamping latch to push the pens against their respective datums, while providing Z adjustments by moving one end of the common wall.
There is a need for a pen installation system that allows easy replacement of the pens, while assuring a high degree of repeatability in aligning the pens for optimal print quality. Moreover, there is a need for a more economical pen installation system that achieves pen positioning tolerances comparable to the earlier two-pen and four-pen carriage designs, without costly secondary machining operations. Thus, a need exists for an improved pen installation system that maintains printhead alignment during printing for optimal print quality.

Summary of the Invention

According to one aspect of the present invention, an integrated reciprocating cartridge is provided for shuttling along a guide rod across an interaction zone of a hardcopy mechanism. The integrated reciprocating cartridge has a body and a head supported by the body for interaction with a print media. This cartridge also has a guide rod grasping member supported by the body to releasably and slideably grasp the guide rod for reciprocal movement of the head across the interaction zone.
According to another aspect of the present invention, a hardcopy mechanism is provided as including a chassis that defines an interaction zone. A guide rod is supported by the chassis to extend across the interaction zone. The hardcopy mechanism also has an integrated cartridge, which may be as described above.
In one illustrated embodiment, the integrated cartridge is an inkjet cartridge, while in another embodiment, the integrated cartridge is a scanning cartridge. The inkjet cartridge may be used in a hardcopy menchanism dedicated solely to printing, and the scanning cartridge may be used in a hardcopy menchanism dedicated solely to scanning. In a multi-function hardcopy device, the inkjet cartridge and the scanning cartridge may be interchangeable, or they may both be simultanelusly mounted to the guide rod so both printing and scanning capabilities are available at all times.
An overall goal of the present invention is to provide an inkjet printing mechanism which uses inkjet pens and ink supplies that are easy to install and remove when empty, to provide consumers with a robust inkjet printing unit.
Another goal of the present invention is to provide an inkjet cartridge installation system that accurately aligns the printheads, then maintains this alignment, to provide optimal print quality.
A further goal of the present invention is to provide an inkjet cartridge installation system which, without sacrificing print quality, provides consumers with an inkjet printing mechanism which is economical to operate.

Brief Description of the Drawing

FIG.1 is a partially cut away perspective view of an inkjet printing mechanism incorporating a first form of an inkjet cartridge installation system of the present invention, here for a replaceable inkjet cartridge.
FIG. 2 is a partially cut away perspective view of a portion of an inkjet printing mechanism incorporating a second form of an inkjet cartridge installation system of the present invention, here shown as an off-axis inkjet printer.
FIG. 3 is an enlarged, exploded, front perspective view of a third form of an inkjet cartridge installation system of the present invention, here shown for a snapper-type inkjet cartridge system.
FIG. 4 is a rear perspective view of the system of FIG. 3, shown assembled.
FIG. 5 is an enlarged side elevational view of one form of an integral guide rod bearing of FIGS. 3 and 4.
FIG. 6 is an enlarged side elevational view of another form of an integral guide rod bearing which may be substituted for the bearing of FIG. 5.
FIG. 7 is an enlarged rear perspective view of the first form of the installation system of FIG. 1, shown with two replaceable inkjet cartridges.
FIG. 8 is an enlarged rear perspective view of the second form of the installation system of FIG. 2, showing one manner of installing one of the off-axis inkjet cartridges.
FIG. 9 is an enlarged front perspective view of one form of a scanning cartridge installation system of the present invention.

Detailed Description of a Preferred Embodiment

FIG. 1 illustrates a first embodiment of hardcopy device, an inkjet printing mechanism, here shown as an inkjet printer 20, constructed in accordance with the present invention, which may be used for printing for business reports, correspondence, desktop publishing, and the like, in an industrial, office, home or other environment. A variety of inkjet printing mechanisms are commercially available. For instance, some of the printing mechanisms that may embody the present invention include plotters, portable printing units, copiers, cameras, video printers, and facsimile machines, to name a few. For convenience the concepts of the present invention are illustrated in the environment of an inkjet printer 20.
While it is apparent that the printer components may vary from model to model, the typical inkjet printer 20 includes a chassis 22 surrounded by a housing, casing or enclosure 23, typically of a plastic material. Sheets of print media are fed from an input supply tray 24 through an interaction zone, which here, for printer 20 comprises a printzone 25, by a print media handling system 26 using a series of conventional media drive rollers (not shown). The print media may be any type of suitable sheet material, such as paper, card-stock, transparencies, mylar, and the like, but for convenience, the illustrated embodiment is described using paper as the print medium. As shown for paper 27, after printing the sheet 27 is propelled onto a pair of retractable output drying wing members 28. The pair of wings 28 momentarily hold the newly printed sheet 27 above any previously printed sheets still drying in an output tray 29 before retracting to the sides to drop the newly printed sheet into the output tray.
The printer 20 also has a printer controller, illustrated schematically as a microprocessor 30, that receives instructions from a host device, typically a computer, such as a personal computer (not shown). Indeed, many of the printer controller functions may be performed by the host computer, by the electronics on board the printer, or by interactions therebetween. As used herein, the term "printer controller 30" encompasses these functions, whether performed by the host computer, the printer, an intermediary device therebetween, or by a combined interaction of such elements. The printer controller 30 may also operate in response to user inputs provided through a key pad 32 located on the exterior of the casing 23. A monitor coupled to the computer host may be used to display visual information to an operator, such as the printer status or a particular program being run on the host computer. Personal computers, their input devices, such as a keyboard and/or a mouse device, and monitors are all well known to those skilled in the art.
One or more inkjet cartridges, described in further detail below, are slideably supported for reciprocal travel back and forth across the printzone 25 for printing, and into a servicing region 34 for maintenance, by an inkjet cartridge guide rod 35. The guide rod 35 is supported by the chassis 22, preferably in a fixed location above the printzone 25. The printer 20 also has a cartridge drive mechanism, such as a DC motor and drive gear assembly 36 coupled to drive an endless belt 38. The motor of assembly 36 operates in response to control signals received from the controller 30.
In the printzone 25, the media sheet 27 receives ink from a new integrated inkjet cartridge architecture, here illustrated as a black ink cartridge 40 and a color ink cartridge 42, both constructed in accordance with the present invention as described further below with respect to FIG. 7. The cartridges 40 and 42 are often called "pens" by those in the art. The pens 40, 42 travel back and forth, that is, they "reciprocate" over the printzone 25 along a scan axis 43. The scan axis 43 is parallel with the X axis and is defined by the guide rod 35. The illustrated color pen 42 is a tri-color pen, although in some embodiments, a pair of discrete monochrome pens may be used. While the color pen 42 may contain a pigment based ink, for the purposes of illustration, pen 42 is described as containing three dye based ink colors, such as cyan, yellow and magenta. The black ink pen 40 is illustrated herein as containing a pigment based ink. It is apparent that other types of inks may also be used in pens 40, 42, such as paraffin based inks, as well as hybrid or composite inks having both dye and pigment characteristics.
The illustrated pens 40, 42 each have bodies that define reservoirs for storing a supply of ink therein. The bodies of pens 40, 42 each support printheads 44, 46 respectively, each of which have an orifice plate with a plurality of nozzles formed therethrough in a manner well known to those skilled in the art. The illustrated printheads 44, 46 are thermal inkjet printheads, although other types of printheads may be used, such as piezoelectric printheads. The printheads 44, 46 typically include a plurality of resistors which are associated with the nozzles. Upon energizing a selected resistor, a bubble of gas is formed ejecting a droplet of ink from the nozzle and onto a sheet of paper in the printzone 25 under the nozzle. The printhead resistors are selectively energized in response to firing command control signals delivered by a multi-conductor strip 48 from the controller 30 to the printheads 44, 46, as described further below. The pens 40, 42 are illustrated as replaceable inkjet cartridges, which when emptied are removed and replaced with fresh cartridges having new printheads 44, 46. Thus, the illustrated printer 20 may be considered as a "replaceable cartridge" inkjet printer.
FIG. 2 illustrates a portion of another embodiment of an inkjet printing mechanism, here showing the ink delivery portion of an "off-axis" inkjet printer 20', constructed in accordance with the present invention. Rather than using the replaceable cartridges 40, 42 of printer 20, the off-axis printer 20' has a slightly different configuration for chassis 22', casing 23', controller 30', guide rod 35', service station 34', scan axis 43', and flexible cable 48' because four monochrome cartridges are used instead of a black cartridge 40 and a tri-color cartridge 42. Specifically, the off-axis printer 20' dispenses ink using a new integrated inkjet cartridge architecture, here shown for a black ink cartridge 50 and three color ink cartridges 52, 54 and 56, all constructed in accordance with the present invention as described further below with respect to FIG. 8. The off-axis inkjet cartridges 50-56 are also often called "pens" by those in the art.
The black ink pen 50 is illustrated herein as containing a pigment-based ink. While the illustrated color pens 52-56 may contain pigment-based inks, for the purposes of illustration, color pens 52-56 are described as each containing a dye-based ink of the colors cyan, magenta and yellow, respectively. It is apparent that other types of inks may also be used in pens 50-56, such as paraffin-based inks, as well as hybrid or composite inks having both dye and pigment characteristics.
The illustrated pens 50-56 each include small reservoirs for storing a supply of ink in what is known as an "off-axis" ink delivery system, which is in contrast to a replaceable cartridge system where each pen has a reservoir that carries the entire ink supply as the printhead reciprocates over the printzone 25 along the scan axis 43. Hence, the replaceable cartridge system of FIG. 1 may also be considered as an "on-axis" system, whereas systems which store the main ink supply at a stationary location remote from the printzone scanning axis 43' are called "off-axis" systems. In the illustrated off-axis printer 20', ink of each color for each printhead is delivered via a conduit or tubing system 58 from a group of main stationary reservoirs 60, 62, 64 and 66 to the on-board reservoirs of pens 50, 52, 54 and 56, respectively. The stationary main reservoirs 60-66 are replaceable ink supplies stored in a reservoir receptacle 68 which is supported by the printer chassis 22'. The bodies of each of pens 50, 52, 54 and 56 support printheads 70, 72, 74 and 76, respectively, which selectively eject ink to from an image on a sheet of media in the printzone 25.
The printheads 70, 72, 74 and 76 each have an orifice plate with a plurality of nozzles formed therethrough in a manner well known to those skilled in the art. The nozzles of each printhead 70-76 are typically formed in at least one, but typically two linear arrays along the orifice plate. Thus, the term "linear" as used herein may be interpreted as "nearly linear" or substantially linear, and may include nozzle arrangements slightly offset from one another, for example, in a zigzag arrangement. Each linear array is typically aligned in a longitudinal direction parallel with the Y axis and perpendicular to the scanning axis 43', with the length of each array determining the maximum image swath for a single pass of the printhead. The illustrated printheads 70-76 are thermal inkjet printheads, although other types of printheads may be used, such as piezoelectric printheads. Thermal printheads 70-76 typically include a plurality of resistors which are associated with the nozzles. Upon energizing a selected resistor, a bubble of gas is formed which ejects a droplet of ink from the nozzle and onto a sheet of paper in the printzone 25 under the nozzle. The printhead resistors are selectively energized in response to firing command control signals delivered by a multi-conductor strip 48' from the controller 30'.
FIGS. 3 and 4 illustrate a third embodiment of a snapper-type integrated inkjet cartridge architecture 78, constructed in accordance with the present invention, which may be substituted for the replaceable cartridges 40, 42 in the printer 20. The illustrated snapper cartridge system 78 has a printhead structure with four permanent or semi-permanent printheads 80, 82, 84 and 86 for dispensing black, cyan, magenta and yellow inks, respectively. The printheads 80-86 and the inks they dispense may be as described above for printheads 70-76. Each of the printheads 80-86 receive ink from an associated replaceable ink reservoir or supply 90, 92, 94 and 96. Each of the replaceable ink reservoirs 90-96 are replaceably received within a body comprising a printhead carriage 100, which also supports the printheads 80-86. The carriage 100 defines four reservoir stalls 102, 104, 106 and 108 for receiving the respective ink supplies 98, 92, 94 and 96. A variety of different ways known to those skilled in the art may be used to couple ink within each of the supplies 90-96 to their associated printheads 80-86 for printing.
A printing mechanism using the illustrated snapper cartridge architecture 78 also includes a backplate member 110, which includes a slider sleeve portion 112 having a bore 114 therethrough which slidably receives the guide rod 35. The bore 114 may have bearings (not shown) mounted or molded therein, which may be separate metallic components or integrally formed of the same plastic material as the backplate. Alternatively, the bore 114 may have a relatively loose fit around the guide rod 35, with a bearing surface being provided by a portion of the carriage 100 or the bearing function may be shared between the backplate 110 and the carriage 100, as discussed further below with respect to FIGS. 5 and 6. The backplate has an upper wall 116 extending upwardly from the slider sleeve 112, and a lower wall 118 extending downwardly from the sleeve 112. Either the top wall 116 or the lower wall 118 of backplate 110 may be used for mounting a variety of components, and the locations and positioning shown herein are by way of illustration only, because it is apparent that various other attachment arrangements may be substituted to perform the desired functions.
The rear-facing surface of the backplate walls 116, 118 may provide a convenient mounting location for several different components. For example, a flexible conductor 48" delivering the firing commands to the printheads 80-86 may be connected to a electronics decoding package 120 mounted to the rear surface of the upper wall 116. To propel the printheads 80-86 across the printzone 25 and the service station area 34, the drive belt 38 may be attached to wall 116 in the same manner as the drive belt is attached to conventional printhead carriages to incrementally advance the printheads along guide rod 35 in response to rotation of motor and gear assembly 36. Preferably, to aid in dynamic stability of carriage 100, the drive belt 38 is attached to the backplate wall 116 as close as possible to the slider sleeve 112, which is preferably located near the center of mass of carriage 100 and reservoirs 90-96 when assembled, as shown in FIG. 4.
To provide carriage positional feedback information to printer controller 30, an encoder strip 122 (also see FIG. 1) extends along the length of the printzone 25 and over the service station area 34. A conventional optical encoder reader 124 may be mounted on the back surface of the lower wall 118 to read positional information provided by the encoder strip 122. To provide accurate positional information, preferably the optical encoder reader 124 is located as close as possible to the orifice plates of the printheads 80-86. The manner of positional feedback information via the encoder strip reader 124, may be accomplished in a variety of different and conventional ways known to those skilled in the art.
As shown in FIG. 3, the backplate 110 also serves the function of delivering the firing signals from the on-board decoder electronics 120 to the printheads 80-86 using an electro-mechanical interconnect or interface, which may be constructed in a variety of different conventional ways known to those skilled in the art. The interface has a carriage coupling assembly 126 and a backplate coupling assembly 128. As shown in FIG. 3, the backplate coupling assembly 128 has four interconnect pads 130, 132, 134 and 136, which may be coupled to four mating carriage interconnects, such as the carriage interconnect pin arrangements in U.S. Patent Nos. 4,706,097 and 5,295,839, assigned to the present assignee, Hewlett-Packard Company. An example of another interconnect system is described below with respect to FIG. 8.
A printing mechanism using the illustrated snapper cartridge architecture 78 has a carriage 100 that preferably includes a pair of guide rod grasping members, such as a pair of fingers or hook members 138, 140 which slidably receive the guide rod 35. The backplate slider sleeve 112 is sandwiched on the rod 35 between the hooks 138 and 140 to positively locate the carriage 100 and printheads 80-86 in the X axis direction, parallel with the scanning axis 43. To allow for smooth gliding action of the carriage 100 along the guide rod 35, preferably each of the hooks 138, 140 houses a bearing assembly 142, as shown in FIG. 5 for hook 140. Preferably, bearings 142 are insert molded into the carriage hooks 138 and 140 when the carriage 100 is formed. Even more preferably, the bearings 142 may be of a plastic material and integrally formed with carriage 100, with a carbon-filled plastic having a Teflon material or other low-friction additive being one preferred composition. While a variety of different conventional types of bearings or bushings may be used, one preferred bearing assembly 142 uses the upper portion of a V-groove type glide bearing, as shown in U.S. Patent No. 5,366,305, assigned to the present assignee, Hewlett-Packard Company.
In FIG. 5, the glide bearing 142 defines a generally inverted V-shaped, upper peripheral region defining a bearing surface 144. To positively push the guide rod 35 and bearing surface 144 into contact with each other, an optional bearing preloader member 145 may extend from the backplate 110 into contact with a lower surface of the guide rod 35. To accommodate this contact when a single preloader 145 is centrally mounted on the backplate 110, the slider sleeve 112 may have a window 145' cut therethrough to define an opening through which the preloader 145 extends. While the illustrated preloader 145 is shown as a leaf spring, it is apparent that other types of preloaders may be used, such as a pair of preloaders extending from each side of the backplate lower wall 118. Indeed, other types of biasing elements may be used to urge the guide rod 35 into contact with the bearing surface 144, such as a coil type spring .
The illustrated glide bearing 142 shows the bearing surface 144 as having a pair of opposing, symmetrically arcuately spaced, substantially planar contact surfaces 146 and 148 located preferably relative to a clock face, at approximately 1:30 and 10:30 o'clock, which together have an inverted V-shape. Under the weight of the carriage assembly 100 when carrying the ink supplies 90-96, the guide rod 35 is positioned within the bearings 142 so the planar contact surfaces 146, 148 of the bearing ride along the guide rod in a stable relationship that resists forces in the Y axis direction. Gravity, or when a preloader 145 is used, both gravity and the preloader, act upon the glide bearings 142 so only surfaces 146, 148 contact the guide rod 35, which advantageously minimizes friction during printing. To further aid in minimizing friction, preferably the bearings 142 are made from an oil-impregnated bronze manufactured through a sintering process, although integrally molded plastic bearings may be even more preferred. The angle of intersection between two planes defined by contact surfaces 146, 148, most preferably is approximately 90 degrees, although other angular variations may prove more practical in other implementations. While the illustrated shape of the bearing contact surfaces 146, 148 is planar, other shapes may be used, such as relatively large-radius, concave or convex, cylindrical sections.
FIG. 6 shows a shared bearing assembly 149 where the hooks 138, 140 house a glide bearing 142' that forms basically the right half of the generally inverted V-shaped bearing 142 of FIG. 5, with bearing 142' having an upper peripheral region 144' defining a bearing surface 146'. The bearing assembly 149 may also include an optional preloader 145 (not shown) as described above with respect to FIG. 5. The shared bearing assembly 149 also has a portion of the bearing surface defined by the backplate slider 112, with the interior surface of the bore 114 defining a bearing surface 148' that forms basically the left half of the generally inverted V-shaped bearing 142 shown in FIG. 5. The gripping action of the hooks 138, 140, under the weight of gravity, with or without the urging action of preloader 145, draws both the bearing surfaces 146' and 148' into contact with the bearing surface of the guide rod 35. The bearing surfaces 146', 148' may be constructed as described above for the bearing 142, and preferably they are integrally molded with the hooks 138, 140 and the backplate slider 112, respectively. Of course, while the illustrated shape of the bearing contact surfaces 146', 148' is planar, other shapes may be used, such as relatively large-radius, concave or convex, cylindrical sections for either or both bearing surfaces 146', 148'.
To hold the printheads 80-86 in a desired relatively horizontal orientation, generally parallel to the X-Y plane or at some fixed angle relative thereto, the carriage has an anti-rotation member, such as a roller member 150. The roller 150 is mounted to an axle member 152 extending from a lower surface 154 of the carriage 100. The roller 150 rolls along a lateral surface 155 of the chassis 22 during printing to prevent the carriage from rotating in a -X direction around the X axis. Advantageously, the roller 150, in combination with the pair of bearings 142 inside each of the hook members 138, 140, provides a three-point carriage support system.
Now the basic concepts of the new integrated inkjet cartridge architecture with integrally formed guide rod bearings is understood with respect to a snapper cartridge system 78, these concepts will be expanded to an integrated replaceable cartridge architecture 156, shown in FIG. 7, using the replaceable cartridges 40, 42 of FIG. 1. Here we see a modified backplate 110' having upper and lower walls 116', 118', and a slider sleeve 112' surrounding the guide rod 35, as described above for sleeve 112. Other components having the same function as described above continue to have their same item numbers, although their mounting locations on the backplate 110' may differ from those shown in FIGS. 3 and 4. For instance, the carriage drive belt 38 is shown mounted to the backplate lower wall 118', although it may be more preferable to mount the belt 38 closer to the center of gravity of the backplate and cartridges 40, 42 as shown in FIG. 4.
The integrated replaceable cartridge architecture 156 of FIG. 7 eliminates the ink supply carriage 100, and instead uses cartridges 40, 42 each having their own sets of guide rod grasping fingers or hook members. The body of the black pen 40 has hook members 138' and 140' extending therefrom, while the body of the color pen 42 has hook members 138" and 140" extending therefrom, each of which may be constructed as described above for hooks 138, 140, including the bearing assemblies 142 or 142' of FIGS. 5 and 6. To seat the cartridges 40 and 42, the backplate 110' defines a series of hook-receiving slots 158, 160, 162 and 164 therethrough which are located to receive hooks 138', 140', 138" and 140", respectively. These hook slots 158-164 preferably extend through a portion of the periphery of the backplate slider sleeve 112' to allow the contact surfaces 146, 148 (FIG. 5) of the bearings 142, or contact surface 148' of bearings 142' (FIG. 6) to ride along the bearing surface of the guide rod 35.
The integrated replaceable cartridge architecture 156 is shown in FIG. 7 with an alternate anti-rotation system 165 used to hold the printheads 44, 46 in a desired orientation to prevent rotation in a -X direction around the X axis, which may be substituted for the anti-rotation roller 150 of FIGS. 3 and 4. Here, a pair of glider members 166 are shown extending downwardly from a lower surface of the black cartridge 40, and another pair of glider members 168 extend downwardly from a lower surface of the color cartridge 42, and which are preferably integrally molded with the cartridge body. Friction between the gliders 166, 168 and the chassis glide surface 155 may be minimized through use of a lubricant, or more preferably, by constructing either the gliders 166, 168 or surface 155 of a low-friction material, such as of a plastic impregnated with a Teflon additive. While only a single glider may be used for each cartridge 40, 42 to provide a three-point support system in combination with the cartridge hooks, use of a pair of gliders for each cartridge advantageously provides increased lateral stability.
FIG. 7 also shows another alternate hook-type anti-rotation system 170, which may be substituted for either the glider system 165 or for the anti-rotation roller 150 of FIGS. 3 and 4. In this hook-type anti-rotation system 170, each of the cartridges 40, 42 has an anti-rotation hook member 172, 174, respectively, extending upwardly from an upper portion of each cartridge body, and preferably being integrally molded with the cartridge body. The anti-rotation hooks 172 and 174 surround and slide along a lateral surface 175 of the chassis 22 during printing to prevent the pen 40, 42 from rotating in a -X direction around the X axis. Friction between the hooks 172, 174 and the slide surface 175 may be minimized as described above for the glider system 165. It is apparent from the illustrated variety of anti-rotation systems 150, 165 and 170, that this feature may be accomplished in a variety of different ways.
FIG. 8 applies the basic concepts of the new integrated inkjet cartridge architecture to an integrated off-axis cartridge architecture 176, showing the black off-axis cartridge 50 of FIG. 2. Here we have another modified backplate 110" including upper and lower walls 116", 118", and a slider sleeve 112" surrounding the guide rod 35' of printer 20'. For clarity, the attachment of the drive belt 38', the reader for the encoder strip 122', and the flex circuit 48' to the backplate 110" has been omitted from the view of FIG. 8, but they may be mounted as described above with respect to FIGS. 4 or 7 for belt 38, reader 124, and flex circuits 48", 48. The on-board firing signal decoder electronics 120 are also omitted for clarity from the view of FIG. 8. The cartridges 50-56 may be provided with any of the anti-rotation systems 150, 165 or 170 described above, along with any of their structural equivalents, but such anti-rotation devices have also been omitted for clarity from the view of FIG. 8.
FIG. 8 shows one form of an electro-mechanical interconnect 126' and 128' for delivering firing signals from the backplate 110" to the printhead resistors in the integrated off-axis cartridge architecture 176, and it is apparent that these concepts may be equally applied to the snapper system 78 or to the replaceable cartridge system 156. For the purposes of illustration, the black pen 50 is shown, and the concepts illustrated herein are typical to pens 52, 54, and 56. The pen 50 includes an electrical interconnect 177 located along a rearward facing portion of the cartridge. The electrical interconnect 177 may include a conventional flex tab circuit having a plurality of electrical interconnect pads (shown as dots in FIG. 8), which may be constructed as described in U.S. Patent No. 4,907,018, assigned to the present assignee, Hewlett-Packard Company. In this location, the flex tab circuit of interconnect 177 may be conveniently extended to make electrical contact with the firing resistors of printhead 70. The interconnect pads of the interconnect 177 are located to be in electrical contact with a series of matching contact pads on a flex strip 130' mounted to the backplate 110". The pen flex 177 carries the electrical signals received from the backplate flex 130' to the firing resistors which heat the ink to eject droplets from the nozzles of printhead 70.
To provide a solid physical contact between the pads of the black pen interconnect 177 and the backplate flex strip 130', preferably flex strip 130' is supported by a pusher member 178, which is biased by a spring 190 to push the carriage flex strip 130' into contact with the pen interconnect 177. A variety of other mechanisms have been used over the years for pushing together the two portions 126' and 128' ofthe electro-mechanical interconnect, so the spring 190 is shown merely as a presently preferred embodiment for accomplishing this action, and it is apparent that a variety of other mechanisms may be substituted for the spring 190.
The integrated off-axis cartridge architecture 176 of FIG. 8 also eliminates the ink supply carriage 100, and instead uses cartridges 50-56. The bodies of each of the cartridges 50-56 have a set of guide rod grasping fingers or hook members extending therefrom, as shown for hook members 138''' and 140''' on the black pen 50, which may be constructed as described above for the hook members 138, 140, including the bearing assemblies 142 or 142' of FIGS. 5 and 6. To seat the cartridges 50-56, for each cartridge the backplate 110" defines a pair of hook-receiving slots 192 and 194 therethrough which are located to receive hooks 138"' and 140"', respectively. These hook slots 192, 194 preferably extend through a portion of the periphery of the backplate slider sleeve 112", as shown for slot 195, to allow the contact surfaces 146, 148 (FIG. 5) of the bearings 142, and surface 148' of bearings 142' (FIG. 6) to ride along the bearing surface of the guide rod 35'.
To allow the pen 50 to receive black ink from the main storage reservoir 60 in the illustrated off-axis printer 20', the pen 50 has a hollow inlet needle 196, located along a rearward portion of the pen 50. The straight needle 196 is guarded by a shroud 198 to prevent an operator's fingers from inadvertently coming in contact with the needle. The backplate 110" supports an inlet valve 200 on a ledge or shelf 201 projecting from a rear surface of the upper wall 116". The inlet valve 200 has an elastomeric septum 202 defining a preformed slit 204 therethrough. The valve 200 is coupled to a black ink tube 58' to receive black ink from the main reservoir 60. The black ink tube 58' is part of the tube assembly 58 in FIG. 1 that delivers ink from each of the main reservoirs 60-66 to the respective pens 50-56.
The inlet needle 196 on the pen 50 is rigidly mounted within the shroud 198 to pierce the septum 202 along slit 204 during pen installation. The shroud 198 is sized to surround the valve 200. While the valve 200 is preferably constructed to tilt slightly with respect to the backplate shelf 201, it is apparent from this construction that insertion of needle 196 into septum 202, as well as removal therefrom, must use a substantially linear motion as indicated by arrow 206 in FIG. 3. Thus, during pen installation, the pen hooks 138" and 140" are first inserted through the backplate slots 192, 194, followed by a downward motion in the direction of arrow 206, which allows needle 196 to pierce septum 202 while the bearings 142 of hooks 138", 140" are seated in their associated backplate slots 195.
FIG. 9 shows another form of a reciprocating cartridge comprising a shuttling scan cartridge 220 constructed in accordance with the present invention which may be placed into a scanning hardcopy device, or a multiple function hardcopy device, which perhaps both prints new images in the interaction printzone 25 and reads previously printed images, where the interaction zone is then considered a scan zone 25'. The printer 20 of FIG. 1 may be easily modified into a such a scanning hardcopy device 20", or a multiple function hardcopy device, by using a modified scanner controller 30" which may also be modified to accommodate the needs of a multiple function hardcopy device. To construct a scanner 20', the inkjet cartridges 40, 42 (FIGS. 1 and 7) or the snapper carriage 100 (FIGS. 3 and 4) may be replaced with the scan cartridge 220. Alternatively, the scan cartridge 220 may be mounted on the guide rod 35 or 35' in addition to the full compliment of inkjet caartridges 40-42, 50-56, 90-96 by modifying the backplate to accommodate both printing and scanning, and thus, to provide a multi-function hardcopy device, with full printing and scanning capacity available at any time. The scan cartridge 220 has a body which supports a scanning head 222 that may be constructed in a variety of conventional ways known to those skilled in the art, several of which are discussed in U.S. Patent No. 5,410,347, currently assigned to the present assignee, the Hewlett-Packard Company.
The scan cartridge 220 may have a pair of guide rod grasping fingers or hook members constructed as described above for hooks 138, 140, and illustrated in FIG. 9 as hook 140, including the bearing assemblies 142 or 142' (FIGS. 5-6). The scanner 20" or multi-function hardcopy device, includes a backplate 110" which may have the same basic construction as backplate 110, but with a modified electronics package 120', which sends scan signals representative of a previously printed image being scanned to the controller 30". An encoder strip 122 and a drive belt 38 may be coupled to the backplate 110" as described above with respect to FIG. 4 for backplate 110. The anti-rotation function may be provided by roller 150 as shown, or using the anti-rotation glider system 165 or the anti-rotation hook system 170 as shown in FIG. 8.
In some implementations, the controller 30, 30" may be modified to accommodate interchangeable printheads and scan heads, for instance by replacing the replaceable black ink cartridge 40 or the off-axis ink cartridge 50 with a scan head having an exterior configuration which facilitates installation with the slider 112' or 112", respectively. With such an interchangeable system, black images may be printed using a composition black, where a droplet of each color ink (cyan, magenta, and yellow) are printed on top of each other to form a printed dot having a black color. Thus, printers 20, 20' may be easily converted into multifunction hardcopy devices whenever desired by the consumer. Alternatively, with the scanner cartridge 220 mounted on guide rod 35, 35' along with all of the inkjet printheads 40-42, 70-76, 80-86, full printing and full scanning capability is always available.

Conclusion

To provide a high quality image on sheet 27 as a hardcopy output of printer 20, 20', the positioning of the printheads 44-46, 70-76, and 80-86 must be precise, relative to each other, and to the entire printing system, as well as being repeatable. That is, when an empty cartridge is replaced by an operator, the alignment of the new full cartridge must be the same as the empty cartridge. The positioning of cartridges in the replaceable system 156, as well as in the off-axis system 176, is one of the primary variables that controls the registration of the ink droplets on the print medium because this positioning affects the orientation of the printheads 44-46 and 70-76. In the snapper system 78, replacement of the ink supplies 90-96 is not as critical because the printheads 80-86 are permanently housed in the carriage 100. Thus, positioning of the carriage 100 relative to the guide rod 35 becomes the critical concern in the snapper system 78.
In the past, the replaceable inkjet pens were housed in a carriage which was slidably coupled to a guide rod for reciprocation over the printzone 25. Any misalignment between the printheads, as well as any absolute misalignment of the printheads relative to the printzone and print media, results in a degradation of print quality. Thus, the theta Z alignment, the pen-to-pen alignment, and the absolute alignment of the pens relative to the media 27 are each of major importance in achieving high print quality. As mentioned in the Background section above, these earlier carriages were expensive to manufacture because they were molded with very tight tolerances, which required to align each pen with respect to all six axial orientations: X axis, Y axis, Z axis, theta X, theta Y, and theta Z. The pen bodies also had to be molded with very tight tolerances at their datums, and in some instances, costly secondary machining operations were needed to meet the tight tolerance requirements. The pen datums were often seated on the carriage datums using a complex latch mechanism, which further added to the expense of the earlier carriage systems.
Fortunately, this new integrated cartridge architecture, as illustrated for the snapper system 78, the replaceable cartridge system 156, and the off-axis system 176 advantageously eliminates many of the drawbacks experienced with these earlier carriage systems, while still providing a printhead alignment system that prints high quality images. For instance, the elimination of the latching mechanisms results in more accurate location of the orifice plates of the printheads 44-46, 70-76 to the guide rod 35 because the latching loads and corresponding deflections are no longer incorporated in the load path between the guide rod bearings and the orifice plate for each pen. Advantageously, the integrated unitary structure of the printheads and guide rod bearings 142 have eliminated these component flexure variations experienced with the earlier carriage systems.
The integrated cartridge architecture introduced herein has the guide rod bearings 142 integrally supplied with the cartridges in the replaceable system 156, and the off-axis system 176, and with the printhead carriage 100 in the snapper system 78. The design philosophy illustrated by the examples of systems 78, 156 and 176 keeps the cartridges 40-42 and 50-56, as well as the snapper carriage 100, as simple as possible by including only necessary components, such as the inverted-V bearing 142. Including this inverted V-bearing into the hook members 138, 140, 138', 140', 138", 140", 138"' and 140" adds immense value to the overall system, with the bearings 142 being easy to mold into the hook members, while allowing easy removal of the cartridges 40-42, 50-56, and of the carriage 100, from the guide rods as 35, 35'.
Another advantage of the integrated architectures of the snapper system 78, the replaceable system 156, and the off-axis system 176 is the overall smaller size of the printhead to guide rod interface. This smaller size results from the elimination of complex latches and redundant plastic which was required in the earlier carriage systems to completely surround the inkjet cartridge. As shown above, for the integrated architectures of systems 156 and 176, the entire earlier carriage has been replaced by backplates 110' and 110" in combination with the new integrated cartridges 40-42, 50-56.
As a further advantage of the integrated architectures of systems 78, 156 and 176 is more accurate printhead to guide rod alignment because the earlier separate pen carriage is no longer in the tolerance loop. Here, each of the printheads 44-46, 70-76, and 80-86 are supported by the same rigid structure that supports the guide rod bearings 142, specifically, by the bodies of the replaceable cartridges 40-42, the snapper carriage 100, and the bodies of the off-axis cartridges 50-56. The snapper system 78 has an additional advantage of using a monolithic structure where a single piece of silicon is machined to form the nozzles of all of the printheads 80-86. This monolithic snapper printheads structure advantageously allows the X, Y, and Z directional alignments to the guide rod 35 to be relaxed by the entire order of magnitude. Furthermore, the theta Z alignment may be improved over the earlier carriage systems through the use of wider datum targets afforded by the bearing surfaces 146, 148 of bearings 142. Additionally, these wider datum targets provided by bearings 142 may also lead to improved alignment in the theta X and theta Y orientations.
Dynamic advantages may also be achieved using the integrated cartridge architecture of systems 78, 156 and 176 through the use of the backplates 110, 110' and 110". For instance, both the guide rods 35, 35' and the attachment of the drive belt 38 may be positioned closer to the center of mass of cartridges 40-42, 50-56, and carriage 100 with ink supplies 90-96 installed therein. Another advantage of systems 78, 156, 178 is the positioning of the encoder strip 122 and reader 124 closer to the printzone 25 due to the elimination of the earlier bulky printhead carriages.
Finally, another advantage of the integrated cartridge architecture of systems 78, 156 and 176 is the ease of installation into printers 20, 20'. The cartridges 40-42, 50-56 and carriage 100 are all easily installed by placing their associated guide rods hooks over the guide rods 35, 35', and in FIGS. 7 and 8, by placing these hooks within slots defined by the backplate slider sleeves 112', 112". Furthermore, removal of a worn printhead or an empty cartridge is easily achieved by lifting these hooks off of the guide rod 35, 35', without the use of complicated latching mechanisms.
While the integrated cartridge architecture has been illustrated with respect to a snapper system 78, a replaceable cartridge system 156, and an off-axis cartridge system 176, these concepts may be applied to other cartridge systems developed in the future. Additionally, other modifications may be made to this integrated cartridge architecture, for instance, by using a wider, single hook member instead of the dual hook system 138, 140, or by using additional hook members for attachment to the guide rods 35, 35'. Additionally, rather than using the anti-rotation roller 150, the glider system 165, or the sliding hooks 170, other schemes may be used to prevent rotation of bearings 142 in a theta X direction around the guide rods 35, 35'. For instance, the lower portion of guide rods 35, 35' may be formed with a flat surface, and the bore 114 of the slider sleeve 112 may have a correspondingly flat surface to prevent rotation of the backplate 110 around the guide rod 35. The upper and lower walls of the 116, 1 18 of the backplate 110 would then prevent rotation of the cartridges 40-42, 50-56 or the carriage 100 around the guide rods 35, 35'.
The integrated scanner cartridge 220 has many of the same advantages as the integrated inkjet cartridges and carriages illustrated in FIGS. 1-8. As a further advantage, a scanning mechanism 20" may also serve as a multifunction hardcopy machine by configuring the body of the scanner cartridge 220 to be physically interchangeable with a printing cartridge, such as cartridges 40-42, 50-56, 80-86. As mentioned above, by exchanging the black replaceable inkjet cartridge 40 or the black off-axis inkjet cartridge 50 with a scanner cartridge 220 for simultaneous printing and scanning capabilities, using the "process black" printing system, e.g. a droplet of cyan, of magenta and of yellow inks, at a single pixel on the media to make a black dot on the media 27. Thus, a consumer can have a multifunction hardcopy machine with interchangeable printing capabilities and scanning capabilities that is easily switched between these two configurations.

Claims

An integrated reciprocating cartridge (78; 156; 176; 220) for shuttling along a guide rod (35; 35') across an interaction zone (25; 25') of a hardcopy mechanism (20; 20'; 20"), comprising:

a body (40, 42; 50, 52, 54, 56; 100; 220);

a head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222) supported by the body (40, 42; 50, 52, 54, 56; 100; 220) for interaction with a print media (27); and

a guide rod grasping member (138, 140; 142; 142'; 138", 140"; 138"', 140"') supported by the body (40, 42; 50, 52, 54, 56; 100; 220) to releasably and slideably grasp the guide rod (35; 35') for reciprocal movement of said head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222) across the interaction zone (25; 25').
An integrated reciprocating cartridge (78; 156; 176; 220) according to claim 1 for a hardcopy mechanism (20; 20'; 20") having a backplate member (110; 110'; 110") slideably mounted to the guide rod (35; 35'), wherein the grasping member (138, 140; 142; 142'; 138", 140"; 138"', 140"') releasably grasps the guide rod (35; 35') at the backplate member (110; 110'; 110").
An integrated reciprocating cartridge (78; 156; 176; 220) according to claim 2 for a hardcopy mechanism (20; 20'; 20") with the backplate member (110; 110'; 110") supporting a first portion (128; 128') of an electrical interface, further including a second portion (126; 126') of said electrical interface supported by the body (40, 42; 50, 52, 54, 56; 100; 220) to electrically couple with the first portion (128; 128') of said electrical interface when the grasping member (138, 140; 142; 142'; 138", 140"; 138"', 140"') releasably grasps the guide rod (35; 35') at the backplate member (110; 110'; 110").
An integrated reciprocating cartridge (78; 156; 176; 220) according to any of the preceding claims for a hardcopy mechanism (20; 20'; 20") having a chassis (22; 22') with a surface (155; 156; 175) parallel with the guide rod (35; 35'), further including an anti-rotation member (150; 166, 168; 172, 174) supported by the body (40, 42; 50, 52, 54, 56; 100; 220) to engage said surface (155; 156; 175) during said reciprocal movement of said head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222) across the interaction zone (25; 25') to prevent rotation of the body (40, 42; 50, 52, 54, 56; 100; 220) around the guide rod (35; 35').
An integrated reciprocating cartridge (78; 156; 176; 220) according to any of the preceding claims, wherein said guide rod grasping member (138, 140; 142; 142'; 138", 140"; 138"', 140"') comprises a hook member defining a bearing surface (144; 144') that slides along the guide rod (35; 35') during said reciprocal movement of said head (44, 46; 70, 72, 74, 76; 80, 82, 84, 86; 222).
An integrated reciprocating cartridge according to any of the preceding claims for a hardcopy mechanism comprising an inkjet printing mechanism (20; 20'), wherein:

said head comprises an inkjet printhead (80, 82, 84, 86); and

said body comprises a carriage (100) defining a chamber (102, 104, 106, 108) that replaceably receives an ink container (90, 92, 94, 96) carrying a supply of inkjet ink to fluidically couple the ink container (90, 92, 94, 96) with the printhead (80, 82, 84, 86) for delivery of said inkjet ink thereto.
An integrated reciprocating cartridge according to any of the preceding claims for a hardcopy mechanism comprising an inkjet printing mechanism (20; 20'), wherein:

said head comprises an inkjet printhead (44, 46; 70, 72, 74, 76); and

said body (40, 42; 50, 52, 54, 56) defines an ink reservoir carrying a supply of inkjet ink, with the ink reservoir being permanently fluidically coupled to deliver said inkjet ink to the printhead (44, 46; 70, 72, 74, 76).
An integrated reciprocating cartridge according to claim 7 for a hardcopy mechanism comprising an off-axis inkjet printing mechanism (20') having a main reservoir (60, 62, 64, 66) containing another supply of said inkjet ink and an ink delivery system (58) to fluidically couple the main reservoir to said ink reservoir, wherein:

said head comprises an inkjet printhead (70, 72, 74, 76); and

the integrated cartridge further comprises an ink inlet member (196) which receives said inkjet ink from the ink delivery system (58) for delivery to said ink reservoir.
An integrated reciprocating cartridge according to any of claims 1 through 5 for a hardcopy mechanism comprising a scanning mechanism (20"), wherein:

said interaction zone comprises a scan zone (25'); and

said head comprises a scan head (222) which reads information previously recorded on a sheet of print media (27) in the scan zone.
A hardcopy mechanism (20; 20'; 20"), comprising:

a chassis (22, 22') defining the interaction zone (25; 25');

a guide rod (35; 35') supported by the chassis (22, 22') to extend across the interaction zone (25; 25'); and

an integrated reciprocating cartridge according to any of the preceding claims.