U.S. patent application number 09/431709 was filed with the patent office on 2002-02-07 for pivoted printhead handle with recessed rest position.
This patent application is currently assigned to Hewlett-Packard Company. Invention is credited to COCKLIN, THOMAS, ECKARD, B. MICHAEL, KEARNS, JAMES P., LANGFORD, JEFFREY D., MCKITTRICK, GARY P., WILLIAMS, KENNETH R..
Application Number | 20020015077 09/431709 |
Document ID | / |
Family ID | 22281524 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020015077 |
Kind Code |
A1 |
ECKARD, B. MICHAEL ; et
al. |
February 7, 2002 |
PIVOTED PRINTHEAD HANDLE WITH RECESSED REST POSITION
Abstract
An inkjet print cartridge is provided for removable installation
in a carriage which typically holds a plurality of print cartridges
of different color printing liquids. In order to minimize overall
size of the printer and its carriage, a handle is pivotally mounted
on a crown of the print cartridge to move from a down recessed
position during normal printing and servicing operations to an
upraised position for gripping while removing the printhead from a
carriage chute. The handle forms a loop to facilitate gripping with
the fingers and thumb, and in its preferred form is bendable in
order to provide flexible yielding upon application of undesirable
lateral or torsional forces during a removal procedure.
Inventors: |
ECKARD, B. MICHAEL;
(CARDIFF, CA) ; LANGFORD, JEFFREY D.; (LEBANON,
OR) ; MCKITTRICK, GARY P.; (TEMECULA, CA) ;
KEARNS, JAMES P.; (CORVALLIS, OR) ; COCKLIN,
THOMAS; (VANCOUVER, WA) ; WILLIAMS, KENNETH R.;
(VANCOUVER, WA) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Assignee: |
Hewlett-Packard Company
|
Family ID: |
22281524 |
Appl. No.: |
09/431709 |
Filed: |
October 31, 1999 |
Current U.S.
Class: |
347/50 |
Current CPC
Class: |
H05K 1/118 20130101;
B41J 2/1752 20130101 |
Class at
Publication: |
347/50 |
International
Class: |
B41J 002/14 |
Claims
1. An inkjet printing system comprising: a printer frame; a
carriage on said frame including a chute for holding print
cartridges; a printhead unit removably mounted on said carriage in
said chute, and having an electrical interconnect for receiving
control signals and a fluid interconnect for receiving printing
liquid from a supply external to said printhead; a handle pivotally
attached to said printhead unit and movable between a down position
adjacent an outer surface of said printhead unit to an upraised
position to be gripped for purposes of removing said printhead unit
from said chute and providing disengagement of said electrical
interconnect and of said fluid interconnect.
2. The printing system of claim 1 wherein said electrical
interconnect is located on said printhead unit spaced apart from
said handle.
3. The printing system of claim 2 wherein said electrical
interconnect is located on a side surface of said printhead unit
and said handle is located on a top surface of said printhead
unit.
4. The printing system of claim 2 wherein said fluid interconnect
is located on said printhead unit spaced apart from said
handle.
5. The printing system fo claim 4 wherein said fluid interconnect
is located on a side surface of said printhead unit and said handle
is located on a top surface of said printhead unit.
6. The printing system of claim 1 wherein said handle is in the
form of a loop of material having two ends, with said two ends each
pivotally attached to said printhead unit, and further including a
stop member to allow said handle to move on only one pivotal
direction when changing from said upraised position to said down
position..
7. The printing system of claim 1 wherein an end of said handle
extends beyond the perimeter of the printhead unit when said handle
is in said down position.
8. The printing system of claim 1 wherein said handle is recessed
into a top surface of said printhead unit when said handle is in
said down position.
9. The printing system of claim 1 wherein said handle is recessed
into a lateral surface of said printhead unit when said handle is
in said down position.
10. The printing system of claim 1 wherein said handle is formed
from two legs joined together to form a loop, with each of said two
legs being pivotally attached to said printhead unit.
11. The printing system of claim 10 wherein a portion of each of
said legs has a minimum diameter which is less than a minimum
diameter of said loop in order to allow said legs to be flexible
when lateral force is applied to said handle.
12. The printing system of claim 11 wherein a portion of each of
said legs has a minimum diameter which is less than a minimum
diameter of said loop in order to allow said legs to be flexible
when torsional force is applied to said handle.
13. The printing system of claim 1 which further includes a cover
for holding said printhead unit in proper position during a
printing operation, wherein said handle is in said down position
during said printing operation.
14. The printing system of claim 13 wherein said cover includes a
restraint bar contacting said printhead unit during a printing
operation, and said handle in said down position is located at a
position spaced apart from said restraint bar.
15. The printing system of claim 13 wherein said printhead unit
includes a contact area abutting said restraint bar during a
printing operation, and wherein said handle in said down position
is at a location spaced apart from said contact area.
16. The printing system of claim 1 which includes a plurality of
print cartridges each having one of said handles to allow manual
removal of one of said print cartridges while allowing other ones
of said print cartridges to remain installed in said carriage.
17. A print cartridge adapted for removable mounting on a printer
carriage, comprising: a body having an outer surface including a
first surface, a second surface, a third surface and a fourth
surface; a nozzle array on said first surface; an electrical
interconnect on said second surface; a fluidic replenishment
interconnect on said third surface; and a handle on said fourth
surface, said handle being pivotally attached to said body for
movement from a down position with said handle at least partially
recessed into said outer surface to an upraised position for
gripping to remove said print cartridge from the carriage.
18. The print cartridge of claim 17 wherein said first surface,
said second surface, said third surface and said fourth surface
each face in a different direction from each other.
19. The print cartridge of claim 18 wherein said first surface,
said second surface, said third surface and said fourth surface
each face in a a direction which is at least ninety degrees from
each other.
20. A method of installing and removing a print cartridge from a
carriage, comprising: providing a carriage chute having an opening
in substantially only one direction; providing a print cartridge
having an electrical interconnect and an ink replenishment
interconnect; providing a crown on a top surface of the print
cartridge, and a handle pivotally mounted on the crown for movement
between a partially recessed down position and an upraised
position; moving the handle to its upraised position to allow
removal of the print cartridge by gripping and pulling the handle
to disengage said electrical interconnect and said ink
replenishment interconnect from matching interfaces, respectively,
on the carriage; manually pushing against the crown to accomplish
installation of the print cartridge in the chute to engage said
electrical interconnect and said ink replenishment interconnect
with said matching interfaces, respectively, on the carriage; and
maintaining the handle in its down position while the print
cartridge remains installed in the carriage during a printing
operation.
Description
BACKGROUND OF THE INVENTION
[0001] Various problems present themselves in design of current
inkjet printers. Modern inkjet printers print at very high
resolution, for example, 600 or even 1200 dots-per-inch (DPI). As
resolution increases, droplet size typically decreases. With
increased resolution and decreased dot size it becomes more
important that the pens be precisely located in the carriage. To
accomplish accurate positioning of the pen in the carriage, the pen
typically has a set of physical X, Y, and Z datums that are seated
against a corresponding set of datums in the carriage stall.
[0002] Modern inkjet printers typically print in color and have a
plurality of color pens usually printing in cyan, magenta, yellow,
and black. It is often desirable to provide a different pen for
each color, so that if a single pen goes bad, only that pen need be
replaced. However, each pen must be precisely aligned with the
other colors, or the print quality of the printed images will be
degraded. Therefore, the system must not only accommodate precision
placement of the pens in the stalls, but precise alignment among
the colors.
[0003] In addition to the mechanical positioning of the pens within
the carriage, the pens must be fluidically connected to trailing
tubes. The pens usually interface with some type of valve on the
ends of the tubes. The pens make connection with these valves when
they are inserted into the carriage stall. However, if the pen and
valve interface is not correctly designed, the forces exerted on
the pen during fluid interconnection will counteract the precision
positioning of the datums, resulting in the pens being misaligned.
The fluid interconnection mechanism must be designed so as to not
act against the precise positioning resulting from the interaction
of the datums.
[0004] Recent advances in printhead construction have allowed
printheads to be designed to be a permanent or semi-permanent part
of the printer, with separate ink cartridges that are fluidically
connected in some fashion to the printhead.
[0005] Although the pens are preferably a permanent fixture in the
printer, rather than being disposable, it is likely that many such
pens will fail before the end of the life of the printer.
Therefore, some provision must be made so that the pen can be
removed and replaced with a new one. The mechanical datum system
and fluid interconnect must also allow the new pen to be reliably
and precisely positioned during such replacement. The system would
be preferably designed so that installation and subsequent
replacements could be done by a purchaser or by a field repair
person away from factory conditions.
SUMMARY OF THE INVENTION
[0006] The invention provides an inkjet printing mechanism designed
to receive an ink jet pen having a needle and a shroud surrounding
the needle, the shroud attached to the pen by means of a neck the
pen also having pen datums configured for positioning the pen
within a printer carriage. The printer includes a printer chassis
and a media movement mechanism mounted to the chassis and
constructed to position a print medium in a print zone. A carriage
is mounted to the chassis and is constructed to receive the pen and
to position the pen over the print zone. The carriage has a notch
configured to receive the neck when the stall receives the pen. A
valve is movably attached to the carriage and is configured to move
with respect to the carriage to be received by the shroud when the
notch receives the neck. A septum is positioned on the valve and
configured such that when the valve is received by the shroud the
septum is pierced by the needle. A set of carriage datums is formed
in the stall and configured to interface with the pen datums. A
latching mechanism is associated with the carriage and constructed
to seat the pen datums against the carriage datums to finely
position the pen with respect to the carriage.
[0007] The invention also provides a method of installing an inkjet
pen into a carriage of an inkjet printing mechanism. The method
includes the steps of: placing the pen in a stall of the carriage
to guide a neck on the pen into a notch formed in the carriage;
moving the pen further into the stall and, by means of registration
of the pen with walls of the pen stall, guiding a shroud on the pen
over a valve urging the pen further into the stall until pen datums
formed on the pen come into contact with carriage datums formed in
the stall; and seating the pen datums against carriage datums to
finely position the pen within the carriage;
[0008] The invention thus provides for reliable insertion of inkjet
pens within their respective carriage stalls, with successive
guiding mechanisms for aligning various parts of the pen with
corresponding parts of the carriage. The invention allows for
installation or replacements of pens to be reliably and easily done
by a purchaser or by a field repair person away from factory
conditions.
[0009] In order to provide for reliable removal of the print
cartridge, a unique handle is provided for removable installation
in a carriage which typically holds a plurality of print cartridges
of different color printing liquids. In order to minimize overall
size of the printer and its carriage, the handle is pivotally
mounted on a crown of the print cartridge to move from a down
recessed position during normal printing and servicing operations
to an upraised position for gripping while removing the printhead
from a carriage chute. The end of the handle preferable extends
slightly beyond the perimeter of the print cartridge to make it
easily accessible for moving to its upraised position. However, the
handle in its down position is recessed below the top surface of
the print cartridge and thereby avoids interference with the
latching cover, as well as being recessed into both side walls of
the print cartridge to avoid creating any obstruction during
removal or installation procedures. The handle forms a loop to
facilitate gripping with the fingers and thumb, and in its
preferred form is bendable in order to provide flexible yielding
upon application of undesirable lateral or torsional forces during
a removal procedure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of an inkjet printer having an
ink replenishment system for multiple printheads removable mounted
in a carriage;
[0011] FIG. 2 shows one embodiment of a carriage incorporating
features of the invention, with a latching device in open position,
and black and yellow print cartridge in the carriage chutes with
their print cartridge handles down;
[0012] FIGS. 3 and 4 are bottom perspective views of one version of
a print cartridge incorporating features of the invention;
[0013] FIG. 5 is a perspective view showing four print cartridges
in the carriage chutes, with the latching device in intermediate
position;
[0014] FIG. 6 shows the cover down on the print cartridges, with
the latching device almost in closed position;
[0015] FIG. 7 shows the carriage with the latching device in closed
position;
[0016] FIG. 8 is a partially cut-away top view of the carriage with
the print cartridges removed, showing the ink replenishment tube
routing;
[0017] FIG. 9 shows the manner of initially unlatching a cover on
the carriage for the wide format inkjet printer of FIG. 13;
[0018] FIG. 10 shows the cover in open position allowing access to
the printheads;
[0019] FIG. 11 shows the handle moved from its down recessed
position to an upraised position;
[0020] FIG. 12 shows the upraised handle gripped for lifting the
print cartridge from the carriage chute;
[0021] FIG. 13 shows the print cartridge removed from the carriage
chute by gripping the upraised handle without having to hold the
print cartridge itself;
[0022] FIG. 14 shows a display panel indicating the individual
installation status of four print cartridges;
[0023] FIG. 15 is a perspective view showing the handle in
partially upraised position;
[0024] FIG. 16 is a top perspective view showing the handle in
recessed position against the crown of the print cartridge;
[0025] FIG. 17 is a side view of the handle; and
[0026] FIG. 18 is a front view of the handle.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0027] FIG. 1 is a cutaway view of a printer 10 of the invention.
Printer 10 includes a chassis 12, carriage rod 14, carriage 16, ink
cartridge stall 18, ink cartridges 20, 22, 24, 26, printheads
(pens) 28, 30, 32, 34 (shown in outline), controller 36 (shown in
outline), input tray 38, and output tray 40. Controller 36
communicates with pens 28, 30, 32, 34 by means of a flex strip 42,
in a manner well known in the art. Ink cartridge 20 holds black
ink, cartridge 22 holds cyan ink, cartridge 24 holds magenta ink,
and cartridge 26 holds yellow ink. Similarly pen 28 prints black
dots, pen 30 prints cyan dots, pen 32 prints magenta dots, and pen
34 prints yellow dots. Ink is fed from ink cartridges 20, 22, 24,
26 to pens 28, 30, 32, 34 by means of tube assembly 44. Tube
assembly 44 connects with manifold 46, and inside manifold 46 the
individual tubes carrying the four colored inks are separately
routed to their respective valving mechanisms so that ink can be
fed to the pens. Carriage 16 is shown in FIG. 1 in its "home"
position at the right side of the print zone. The print zone
resides between this home position and the left side 48 of chassis
12.
[0028] Carriage 16 rides along carriage rod 14 and traverses in the
direction labeled X back and forth to thereby scan the pens across
the print zone as dots are laid down on the page in a dot matrix
pattern. For this reason, the direction X is commonly referred to
as the carriage axis or scan axis.
[0029] After a print swath is complete, the paper or other print
media is incrementally moved in the direction labeled Y, so that
another print swath can be printed. Subsequent contiguous swaths
are printed to print entire pages of test or images in a manner
well known in the art. The direction orthogonal to directions X and
Y will be referred to herein as the Z axis. After a page of
information is printed, the page is ejected onto the output tray
40, and a new sheet is "picked" from the input tray so that it can
be printed on.
[0030] FIG. 3 and 4 illustrate pen 28 in detail, and is typical of
pens 28, 30, 32, 34. This pen includes printhead nozzles 50,
electrical interconnect pads 52, fluid interconnect needle 54,
shroud 56, and neck 58. Pen 28 has X datums 60, 62, 64; Z datums 66
and 68; and Y datum 70. Contact pads 52 interface with a set of
matching contact pads in the printer so that the printer can
provide firing signals to the pen. Based on these firing signals,
droplets are ejected from nozzles 50. Needle 54 interfaces with a
septum, described later, to provide a supply of ink to the pen.
Shroud 56 covers and protects needle 54. Both shroud 54 and neck 58
serve to guide the needle into its interface with its septum. These
functions are described more completely below.
[0031] FIGS. 2 and 8 illustrate details of carriage 16, and
includes pen stalls 76, 78, 80, 82. Pens 28, 30, 32, 34 are
installed into 76, 78, 80, 82, respectively. Stall 76 is typical
and will be described in detail. Stall 76 includes X, Y, and Z
datums that correspond directly with the X, Y, and Z datums on pen
28, described in reference to FIGS. 3 and 4. For example, in FIG.
2, X datums 84, 86 and Z datum 90 are visible in stall 78, which
datums correspond to the datums on pen 30. Stall 76 also includes
contact pads 96 and notch 100. A spring is positioned behind
contact pads 96 to bias the contact pads outward, or in the
direction of the notch 100.
[0032] As pen 28 is installed into stall 76, neck 58 fits into
notch 100. As the pen is further installed, spring 98 urges the pen
toward the right (as viewed in FIGS. 3 and 4) to bias X pen datums
60, 62, and 64 against the X carriage datums to position the pen in
the X direction within the carriage. Carriage contact pads 96
engage with pen contact pads 52, so that the printer can
communicate with the pen. Also, because of the spring behind
contact pads 96, Y pen datum 70 is urged against its carriage datum
to position the pen in the Y direction. By means of a latch
mechanism described below, Z pen datums 66 and 68 are urged against
the Z carriage datums to position the pen in the Z direction. Thus
the pen is precisely positioned in the X, Y, and Z directions with
respect to carriage 16 so that droplets are accurately deposited on
the page in their intended location.
[0033] FIG. 2 and FIGS. 5-7 illustrate details of the latching
mechanism that latches pens 28, 30, 32, and 34 into their
respective stalls so that the pen datums are all firmly held into
position against their respective carriage datums. This mechanism
includes a carriage chassis 110, latch 112, handle 114, and pivot
arm 116. Carriage chassis rides along carriage rod 14 at hole 118.
A set of contact arms 120 is pivotally connected to latch 112, as
shown, and a spring (not shown) is mounted behind each of contact
arms 120 to urge contact arms 120 outward or away from latch 112.
Handle 114 includes a hook 124, designed to interlock with pivot
arm 116, as described below. Latch 112 is pivotally attached to
carriage chassis 110, and handle 114 is in turn pivotally attached
to latch 112, as shown. Pivot arm 116 is pivotally attached to
carriage chassis 110, as shown.
[0034] FIG. 2 shows the latch mechanism in its fully open position,
with latch 112 flipped back toward the rear of the printer and
handle 114 rotated back behind latch 112. Pivot arm 116 is rotated
forward out of the way. With the latch mechanism in this position,
pens can be installed or exchanged. FIG. 5 shows the latch
mechanism in a second position in which latch 112 is rotated
forward (clockwise as viewed in FIG. 5) so that contact arms 120
are pushing against the pens. Handle 114 is rotated so that hook
124 is interlocked with pivot arm 116. Handle 114 is held by the
user to move the mechanism from the orientation shown in FIG. 2 to
the one shown in FIG. 5. After hook 124 is interlocked with pivot
arm 116, the user rotates handle 114 back toward the rear of the
printer (or counterclockwise as viewed in FIGS. 2, and 5-7). As the
handle is thus rotated, latch 112 will be urged downward so that
contact arms 120 are urged against the pens by means of springs
mounted behind each contact arm. As the user rotates handle 114
toward the position shown in FIG. 7, he will feel a force,
resulting from the springs behind contact arms 120, urging the
handle to rotate back to the orientation shown in FIG. 5.
[0035] When the mechanism reaches the orientation shown in FIG. 6,
the forces reach an equilibrium, and in this position, the
mechanism may therefore be said to be moving through to an a
over-center position. As the user continues to rotate handle 114
toward the position shown in FIG. 7, the forces resulting from the
springs behind contact arms 120 will urge handle 114 to continue
rotating, until the handle is in its position shown in FIG. 7.
Thus, the orientation shown in FIG. 7 is in a stable energy state,
and the handle is therefore in a locked position so that the pens
are firmly held in place. The motion of the latching mechanism from
the position shown in FIG. 5 to the position shown in FIG. 7 may be
referred to as a latching motion. When it is desired to replace a
pen, the user will rotate handle 114 back through the over-center
position (FIG. 6), and back to the position shown in FIG. 5. The
user will then rotate the handle 114 and latch 112 back to the
position shown in FIG. 2.
[0036] In accordance with the design objectives, manifold 46 has
various barriers, walls and clips to channel the ink tubes. Tube
172 carries black ink, tube 174 carries cyan ink, tube 176 carries
magenta ink, and tube 178 carries yellow ink. Each of the tubes has
a different length, and the different lengths of the tubes assists
in the assembly of the tubes and valves in the manifold 46. The
valves 132, 134, 136, 138 are connected to tubes 172, 174, 176.
178, respectively before the tubes are inserted in the
manifold.
[0037] The process for installing pens is now described. This
description is given with regard to pen 28, with the understanding
that the process for installing the other pens is the same. The
user grasps one pen 28 with the needle and printing nozzles facing
down as shown in FIG. 3 and begins to position it within its stall
76. Pen 28 is positioned so that pen contact pads 52 are closest to
carriage contact pads 96. Spring 98 has a high spring tension and
urges pen 28 to the right as viewed in FIG. 2. Because of the
spring behind carriage contact pads 96, contact pads 96 also urge
pen 28 toward the front of stall 76 (i.e., toward notch 100).
Because of the frictional forces between the pen and the walls of
the stall, the user will need to use some force to push the pen
downward into its stall.
[0038] As the user further pushes pen 28 into its stall, neck 58
will engage within and interface with notch 100. As this happens,
notch 100 positions shroud 56 over valve 132. As the user further
pushes the pen down, shroud 56 will engage with valve 132 to locate
valve 132 within shroud 56 and also positions needle 54 above
septum and in position to pierce slit 150.
[0039] The other pens 28, 30, and 32 are similarly installed. At
this point, the latching mechanism is used, as described in
reference to FIGS. 2, 5, 6 and 7 to latch the pens into their
stalls and to firmly position the pen datums against their
respective carriage datums. At this point, the pens are precisely
located in their stalls in the carriage and the fluid interconnect
is made, so that the printer is ready to print.
[0040] The recent embodiment of the unique compact print cartridge
in its presently preferred embodiment is employed in a large format
rollfeed/sheet feed printer. While some of the features are closely
similar to the earlier embodiment shown in FIGS. 3-4 and other
related Figs., new reference numerals will be used for
clarification. In that regard, the print cartridge 602 includes a
body 603 which forms an internal reservoir and a lower snout 604
which extends more than half the distance across a lower end of the
internal reservoir and defines a nozzle area 606 from which ink is
applied to media. An upper crown 608 includes on one end (generally
above the snout) a leak test hole 610, a slanted vector force
contact area 612, and a vent hole 614 to the valve-actuator bellows
surrounded by a primer seal area 615. The other end of the crown
includes a lid 616 which covers an enclosed passage connecting the
fluid interconnect 618 with an inlet valve to the internal
reservoir, and a peripheral ledge 619 which provides a recess for
receiving a handle 620 in its down position. The fluid interconnect
includes a shroud 622 surrounding a downwardly projecting needle
623 which is protected by a plug 624 during shipment and before
installation in the carriage. A color keying component 626 is used
to assure that each print cartridge is installed in its proper
chute or slot in the carriage.
[0041] The datums on the print cartridge include three X datums
630, 632, 634, one Y datum 636 and two Z datums 638, 640 as shown
in the Figs which are arranged to assure proper and secure
positioning against matching datums surfaces in the carriage. In
contrast to some earlier print cartridges, these datums need not be
machined in order to avoid mis-alignment.
[0042] The handle 620 includes enlarged hubs 650 which are
pivotally mounted on pins 652. The hubs are at each end of two
small diameter legs 654 which join together to form a thickened
loop 656 having an outwardly extending tab 658.
[0043] It will be understood from the foregoing description and
accompanying drawings that the print cartridge of the present
invention provides a set of unique mechanical interface features
that enable high performance printheads (sometimes referred to
herein as "pens") designed to receive ink from separable external
ink supplies while maintain a compact printer form factor. This
feature set includes a novel combination of outside form factor,
datum arrangement, latching, and handle which have been matched
with corresponding features in the carriage to facilitate print
cartridge installation, printing, servicing, removal and
replacement while maintaining predictable and precise tolerances
around the required fluid and electrical interconnections.
[0044] The lower height dimension serves to minimize the overall
printer height, and allows a printer to be stored and/or used in
typical nineteen inch rack mountable hardware. The minimal width
serves to diminish the eight-times multiplier effect caused by a
four printhead carriage overtravel on each end of the carriage
scan. Depth has the least impact on the product size, and in fact
the additional depth helps to provides better theta-z rotational
control of the print cartridges mounted in the carriage.
[0045] Weight is important to minimize motor force requirements
which has a direct impact on product cost. Also, printers using
heavier print cartridges often generate objectionable shaking and
vibrations when used on a high performance carriage which has an
increased range of acceleration/deceleration at both ends of the
scan.
[0046] The following table shows the changes for the new 600 dpi
printhead of the present invention as compared to a typical
previous 600 dpi printhead of Hewlett-Packard:
1 # of Nozzles Height Width Depth Weight 300 93 mm 18.7 mm 60 mm
113 gms 512 51 15.9 70 38 gms
[0047] The improved datum arrangement has been developed in order
to successfully implement the small form factor and to assure
precise positioning during the life of a semi-permanent print
cartridge and printhead. In this regard, the datum arrangement
minimizes undesirable theta-z variations. Also, the datum locations
are spaced apart as much as possible from the printhead itself to
minimize any adverse effect of datum engagement generated particles
on successful ink ejection from the printhead.
[0048] The position of the latch force vector minimizes alignment
variation for a small form factor print cartridge. The latch
applies a force of the top of the print cartridge that passes
between the fluid and electrical connections to the printhead. The
fluid and electrical connections are made at opposing ends of the
print cartridge. The latch force vector is applied at a point
between these connections, and in a preferred embodiment is applied
at a point that is proximate to the intersection of a plane that
bisects the nozzle plane and passes through the top of the print
cartridge. The exact predetermined location for applying the latch
force minimizes the overall force required to accurately position
this small form factor print cartridge. Moreover, if there is a
printhead/media crash that knocks the print cartridge out of
alignment, the latch mechanism in combination with the datums will
tend to correctly reseat the print cartridge in that carriage.
[0049] The handle is designed to enable removal of the print
cartridge from the carriage without damaging either the electrical
interconnect or the fluid replenishment interface. The size and
shape of the handle is designed to avoid adding to any of the print
cartridge dimensions, while at the same time providing ease of use.
If a user by mistake leaves the handle in its upraised position and
forgets to rotate it back to the down position, the handle will
tend to automatically return it to the down position.
[0050] The flexible character of the handle allows substantial
force to be applied to the print cartridge only in a
non-destructive and intended direction. Otherwise there is a risk
of damaging the print cartridge or carriage which would result in
ink spillage or other damage which would preclude the printer from
operating properly. If a force is applied in the wrong direction
while removing the print cartridge from the carriage, the legs of
the handle will buckle. This flexible or yielding handle design
also protects the printer if the customer leaves the handle in its
upraised lifting position when installed in the carriage chute,
since it will safely return to its partially recessed down position
when the carriage latching device is closed.
[0051] By having the handle rest in a recessed position relative to
the overall perimeter of the print cartridge and fluid
interconnect, there is no increase to the outside dimensions of the
print cartridges. It also is allowed to rotate downwardly in only
one direction thereby avoiding interference with the application of
the vector force by the latching cover.
[0052] The handle is a different color from the print cartridge
body and is therefore very intuitive to use. It provides feedback
to the user since the handle will begin to buckle if the print
cartridge is being pulled, pushed or twisted in the wrong
direction. The handle is also designed to discourage users from
touching easily damaged electrical contacts as well as keeping them
away from the fluid interconnects or the nozzle plate which may
have residual ink on them. In view of the foregoing it is clear
that the handle is the only logical and feasible way of removing
the print cartridge when it is properly installed in the carriage
chute. Without the handle a user would need a special tool to
remove a print cartridge. Although alternative methods to loosen an
installed print cartridge could be incorporated in the carriage, it
is believed that they would require a user to grip or touch the
body of the print cartridge during or after removal. This could
potentially cause ink to rub or spill on the user or perhaps damage
the print cartridge. Also, alternate approaches would necessarily
require space on the carriage which in turn would probably add to
the overall size of the printer.
[0053] Accordingly it is believed that this pivotally attached not
type of handle is an important improvement over prior handles that
were molded as part of the print cartridge bodies. Such molded
handles on previous print cartridges added to their outside
dimensions, were not necessarily intuitive in their use, and did
not provide safeguards against excessive force being applied to the
print cartridge or carriage in a detrimental way.
[0054] While particular exemplary embodiments have been shown and
described, it will be appreciated by those skilled in the art that
various changes, substitutions and improvements can be made without
departing from the spirit and scope of the invention as set forth
in the following claims.
[0055] We claim as our invention
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