U.S. patent application number 10/320853 was filed with the patent office on 2004-06-17 for solid phase change ink pre-melter assembly and a phase change ink image producing machine having same.
This patent application is currently assigned to Xerox Corporation. Invention is credited to Leighton, Roger, Phillips, Scott J..
Application Number | 20040114010 10/320853 |
Document ID | / |
Family ID | 32326004 |
Filed Date | 2004-06-17 |
United States Patent
Application |
20040114010 |
Kind Code |
A1 |
Leighton, Roger ; et
al. |
June 17, 2004 |
SOLID PHASE CHANGE INK PRE-MELTER ASSEMBLY AND A PHASE CHANGE INK
IMAGE PRODUCING MACHINE HAVING SAME
Abstract
A pre-melter assembly is provided for containing, conditioning
and feeding solid pieces of phase change ink into a melter housing
in a phase change ink image producing machine. The pre-melter
assembly includes (a) a first portion having a first feeding
apparatus and a first container for containing and feeding solid
pieces of phase change ink. It also includes a second portion
having a second container and a second feeding apparatus for
containing and feeding solid pieces of phase change ink to a melter
housing. The pre-melter assembly then includes a cooling device
mounted in heat exchange relationship with the second feeding
apparatus for maintaining a temperature Tw of the solid pieces of
phase change ink below a melting point temperature Tm of the solid
pieces of phase change ink, thereby preventing premature melting of
the solid pieces of phase change ink before the solid pieces reach
the melter housing.
Inventors: |
Leighton, Roger; (Rochester,
NY) ; Phillips, Scott J.; (W. Henrietta, NY) |
Correspondence
Address: |
Patent Documentation Center
Xerox Corporation
20th Floor,
100 Clinnton Ave. S., Xerox Square
Rochester
NY
14644
US
|
Assignee: |
Xerox Corporation
|
Family ID: |
32326004 |
Appl. No.: |
10/320853 |
Filed: |
December 16, 2002 |
Current U.S.
Class: |
347/88 ;
347/85 |
Current CPC
Class: |
B41J 2/17593
20130101 |
Class at
Publication: |
347/088 ;
347/085 |
International
Class: |
B41J 002/175 |
Claims
What is claimed is:
1. A pre-melter assembly for containing, conditioning and feeding
solid pieces of phase change ink into a melter housing in a phase
change ink image producing machine, the pre-melter assembly
comprising: (a) a first portion including receiving means and first
containing means for receiving and containing solid pieces of phase
change ink; (b) a second portion including second containing means
and feeding means for containing and feeding solid pieces of phase
change ink to a melter housing; and (c) a cooling device mounted in
heat exchange relationship with said feeding means of said second
portion for maintaining a temperature Tw of said solid pieces of
phase change ink below a melting point temperature Tm therefor to
prevent premature melting thereof before said solid pieces of phase
change ink reach the melter housing.
2. The pre-melter assembly of claim 1, wherein said first portion
comprises a stationary first basket, and plural feeding tubes
located within and through said stationary first basket for
containing and feeding said solid pieces of phase change ink to the
melter housing.
3. The pre-melter assembly of claim 1, wherein said second portion
is movable relative to said portion.
4. The pre-melter assembly of claim 1, wherein said second portion
comprises a movable second basket and plural thermally conductive
feeding pipes mounted within and through said movable second basket
for containing and feeding said solid pieces of phase change ink to
the melter housing.
5. The pre-melter assembly of claim 1, wherein said cooling device
comprises a heat sink, and said melting point temperature Tm is
110.degree. C.
6. The pre-melter assembly of claim 1, said stationary first basket
is mounted to a portion of a frame of the phase change ink image
producing machine.
7. The pre-melter assembly of claim 2, wherein each feeding tube of
said plural feeding tubes includes a flapper door for closing and
shutting off flow of said solid pieces of phase change ink from
said first portion to said second portion.
8. The pre-melter assembly of claim 4, wherein said thermally
conductive feeding pipes comprise aluminum pipes.
9. The pre-melter assembly of claim 4, wherein said second portion
is mounted inside a movable drawer.
10. The pre-melter assembly of claim 7, wherein said flapper door
automatically closes when said second portion is moved out of
alignment relative to said first portion for preventing spilling of
solid pieces of phase change ink from said first portion, and
automatically opens when said second portion is moved into
alignment relative to said first portion.
11. A phase change ink image producing machine comprising: (a) a
control subsystem for controlling operation of all subsystems and
components of the image producing machine; (b) a movable imaging
member having an imaging surface; (c) a printhead system connected
to said control subsystem for pixel-wise ejecting drops of melted
liquid phase change ink onto said imaging surface to form an image;
and (d) a pre-melter assembly for containing, conditioning and
feeding solid pieces of phase change ink into a melter housing in a
phase change ink image producing machine, the pre-melter assembly
including: (i) a first portion including receiving means and first
containing means for receiving and containing solid pieces of phase
change ink; (ii) a second portion including second containing means
and feeding means for containing and feeding solid pieces of phase
change ink to a melter housing; and (iii) a cooling device mounted
in heat exchange relationship with said feeding means of said
second portion for maintaining a temperature Tw of said solid
pieces of phase change ink below a melting point temperature Tm
therefor to prevent premature melting thereof before they reach the
melter housing.
12. The phase change ink image producing machine of claim 11,
wherein said first portion comprises a stationary first basket
mounted to a frame of the image producing machine, and plural
feeding tubes located within said stationary first basket for
containing and feeding said solid pieces of phase change ink to the
melter housing.
13. The phase change ink image producing machine of claim 11,
wherein said second portion is movable relative to said
portion.
14. The phase change ink image producing machine of claim 11,
wherein said second portion comprises a movable second basket and
plural thermally conductive feeding pipes mounted within and
through said movable second basket for containing and feeding said
solid pieces of phase change ink to the melter housing.
15. The phase change ink image producing machine of claim 11,
wherein said cooling device comprises a heat sink, and said melting
point temperature Tm is 110.degree. C.
16. The phase change ink image producing machine of claim 11,
including a heat retaining frame mounted peripherally within said
melter housing for keeping solid pieces of phase change ink away
from inside walls of said melter housing, and for preventing melted
ink from coalescing against said inside walls of said melter
housing.
17. The pre-melter assembly of claim 12, wherein each feeding tube
of said plural feeding tubes includes a flapper door for closing
and shutting off flow of said solid pieces of phase change ink from
said first portion to said second portion.
18. The phase change ink image producing machine of claim 14,
wherein said thermally conductive feeding pipes comprise aluminum
pipes.
19. The phase change ink image producing machine of claim 14,
wherein said second portion is mounted inside a movable drawer.
20. The phase change ink image producing machine of claim 17,
wherein said flapper door automatically closes when said second
portion is moved out of alignment relative to said first portion
for preventing spilling of solid pieces of phase change ink from
said first portion, and automatically opens when said second
portion is moved into alignment relative to said first portion.
Description
RELATED CASE
[0001] This application is related to U.S. application Ser. No.
______ (Applicants' Docket NO. D/A2366) entitled "SOLID PHASE
CHANGE INK MELTER ASSEMBLY AND PHASE CHANGE INK IMAGE PRODUCING
MACHINE HAVING SAME"; and U.S. application Ser. No. ______
(Applicants' Docket NO. D/A2366Q) entitled "PHASE CHANGE INK
MELTING AND CONTROL APPARATUS AND METHOD AND A PHASE CHANGE INK
IMAGE PRODUCING MACHINE HAVING SAME"; and U.S. application Ser. No.
______ (Applicants' Docket NO. D/A2538) entitled "HIGH SHEAR BALL
CHECK VALVE DEVICE AND A LIQUID INK IMAGE PRODUCING MACHINE USING
SAME", each of which is being filed herewith on the same day and
having at least one common inventor.
BACKGROUND OF THE INVENTION
[0002] This invention relates generally to image producing
machines, and more particularly to a solid phase change ink
pre-melter assembly and a phase change ink image producing machine
or printer having same.
[0003] In general, phase change ink image producing machines or
printers employ phase change inks that are in the solid phase at
ambient temperature, but exist in the molten or melted liquid phase
(and can be ejected as drops or jets) at the elevated operating
temperature of the machine or printer. At such an elevated
operating temperature, droplets or jets of the molten or liquid
phase change ink are ejected from a printhead device of the printer
onto a printing media. Such ejection can be directly onto a final
image receiving substrate, or indirectly onto an imaging member
before transfer from it to the final image receiving media. In any
case, when the ink droplets contact the surface of the printing
media, they quickly solidify to create an image in the form of a
predetermined pattern of solidified ink drops.
[0004] An example of such a phase change ink image producing
machine or printer, and the process for producing images therewith
onto image receiving sheets is disclosed in U.S. Pat. No. 5,372,852
issued Dec. 13, 1994 to Titterington et al. As disclosed therein,
the phase change ink printing process includes raising the
temperature of a solid form of the phase change ink so as to melt
it and form a molten liquid phase change ink. It also includes
applying droplets of the phase change ink in a liquid form onto an
imaging surface in a pattern using a device such as an ink jet
printhead. The process then includes solidifying the phase change
ink droplets on the imaging surface, transferring them the image
receiving substrate, and fixing the phase change ink to the
substrate.
[0005] Conventionally, the solid form of the phase change is a
"stick", "block", "bar" or "pellet" as disclosed for example in
U.S. Pat. No. 4,636,803 (rectangular block, cylindrical block);
U.S. Pat. No. 4,739,339 (cylindrical block); U.S. Pat. No.
5,038,157 (hexagonal bar); U.S. Pat. No. 6,053,608 (tapered lock
with a stepped configuration). Further examples of such solid forms
are also disclosed in design patents such as U.S. D453,787 issued
Feb. 19, 2002. In use, each such block form "stick", "block", "bar"
or "pellet" is fed into a heated melting device that melts or phase
changes the "stick", "block", "bar" or "pellet" directly into a
print head reservoir for printing as described above.
[0006] Conventionally, phase change ink image producing machines or
printers, particularly color image producing such machines or
printers, are considered to be low throughput, typically producing
at a rate of less than 30 prints per minute (PPM). The throughput
rate (PPM) of each phase change ink image producing machine or
printer employing solid phase change inks in such "stick", "block",
"bar" or "pellet" forms is directly dependent on how quickly such a
"stick", "block", "bar" or "pellet" form can be melted down into a
liquid. The quality of the images produced depends on such a
melting rate, and on the types and functions of other subsystems
employed to treat and control the phase change ink as solid and
liquid, the imaging member and its surface, the printheads, and the
image receiving substrates.
[0007] There is therefore a need for a relatively high-speed
(greater than "XX" PPM) phase change ink image producing machine or
printer that is also capable of producing relatively high quality
images, particularly color images on plain paper substrates.
SUMMARY OF THE INVENTION
[0008] In accordance with the present invention, there is provided
a pre-melter assembly for containing, conditioning and feeding
solid pieces of phase change ink into a melter housing in a phase
change ink image producing machine. The pre-melter assembly
includes (a) a first portion having a first feeding apparatus and a
first container for containing and feeding solid pieces of phase
change ink. It also includes a second portion having a second
container and a second feeding apparatus for containing and feeding
solid pieces of phase change ink to a melter housing. The
pre-melter assembly then includes a cooling device mounted in heat
exchange relationship with the second feeding apparatus for
maintaining a temperature Tw of the solid pieces of phase change
ink below a melting point temperature Tm of the solid pieces of
phase change ink, thereby preventing premature melting of the solid
pieces of phase change ink before the solid pieces reach the melter
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In the detailed description of the invention presented
below, reference is made to the drawings, in which:
[0010] FIG. 1 is a vertical schematic of the high-speed phase
change ink image producing machine or printer including the solid
phase change ink pre-melter assembly of the present invention;
[0011] FIG. 2 is a perspective view of a melting and control system
including the solid phase change ink pre-melter assembly of the
present invention; and
[0012] FIG. 3 is an exploded view of the components of the solid
phase change ink pre-melter assembly in accordance with the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] While the present invention will be described in connection
with a preferred embodiment thereof, it will be understood that it
is not intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents as may be included within the spirit and scope of
the invention as defined by the appended claims.
[0014] Referring now to FIG. 1, there is illustrated an image
producing machine, such as the high-speed phase change ink image
producing machine or printer 10 of the present invention. As
illustrated, the machine 10 includes a frame 11 to which are
mounted directly or indirectly all its operating subsystems and
components, as will be described below. To start, the high-speed
phase change ink image producing machine or printer 10 includes an
imaging member 12 that is shown in the form of a drum, but can
equally be in the form of a supported endless belt. The imaging
member 12 has an imaging surface 14 that is movable in the
direction 16, and on which phase change ink images are formed.
[0015] The high-speed phase change ink image producing machine or
printer 10 also includes a phase change ink system 20 that has at
least one source 22 of one color phase change ink in solid form.
Since the phase change ink image producing machine or printer 10 is
a multicolor image producing machine, the ink system 20 includes
for example four (4) sources 22, 24, 26, 28, representing four (4)
different colors CYMK (cyan, yellow, magenta, black) of phase
change inks. The phase change ink system 20 also includes a phase
change ink melting and control assembly 100 (FIG. 2), for melting
or phase changing the solid form of the phase change ink into a
liquid form. Thereafter, the phase change ink melting and control
assembly 100 then controls and supplies the molten liquid form of
the ink towards a printhead system 30 including at least one
printhead assembly 32. Since the phase change ink image producing
machine or printer 10 is a high-speed, or high throughput,
multicolor image producing machine, the printhead system includes
for example four (4) separate printhead assemblies 32, 34, 36 and
38 as shown.
[0016] As further shown, the phase change ink image producing
machine or printer 10 includes a substrate supply and handling
system 40. The substrate supply and handling system 40 for example
may include substrate supply sources 42, 44, 46, 48, of which
supply source 48 for example is a high capacity paper supply or
feeder for storing and supplying image receiving substrates in the
form of cut sheets for example. The substrate supply and handling
system 40 in any case includes a substrate handling and treatment
system 50 that has a substrate pre-heater 52, substrate and image
heater 54, and a fusing device 60. The phase change ink image
producing machine or printer 10 as shown may also include an
original document feeder 70 that has a document holding tray 72,
document sheet feeding and retrieval devices 74, and a document
exposure and scanning system 76.
[0017] Operation and control of the various subsystems, components
and functions of the machine or printer 10 are performed with the
aid of a controller or electronic subsystem (ESS) 80. The ESS or
controller 80 for example is a self-contained, dedicated
mini-computer having a central processor unit (CPU) 82, electronic
storage 84, and a display or user interface (UI) 86. The ESS or
controller 80 for example includes sensor input and control means
88 as well as a pixel placement and control means 89. In addition
the CPU 82 reads, captures, prepares and manages the image data
flow between image input sources such as the scanning system 76, or
an online or a work station connection 90, and the printhead
assemblies 32, 34, 36, 38. As such, the ESS or controller 80 is the
main multi-tasking processor for operating and controlling all of
the other machine subsystems and functions, including the machine's
printing operations.
[0018] In operation, image data for an image to be produced is sent
to the controller 80 from either the scanning system 76 or via the
online or work station connection 90 for processing and output to
the printhead assemblies 32, 34, 36, 38. Additionally, the
controller determines and/or accepts related subsystem and
component controls, for example from operator inputs via the user
interface 86, and accordingly executes such controls. As a result,
appropriate color solid forms of phase change ink are melted and
delivered to the printhead assemblies. Additionally, pixel
placement control is exercised relative to the imaging surface 14
thus forming desired images per such image data, and receiving
substrates are supplied by anyone of the sources 42, 44, 46, 48 and
handled by means 50 in timed registration with image formation on
the surface 14. Finally, the image is transferred within the
transfer nip 92, from the surface 14 onto the receiving substrate
for subsequent fusing at fusing device 60.
[0019] Referring now to FIGS. 2-3, a phase change ink melting and
control assembly 100 that is connected to the ink system 20 is
illustrated. As shown, the phase change ink melting and control
assembly 100 includes a melter assembly 300 for melting or phase
changing solid pieces of phase change ink to form molten liquid
ink. It also includes a molten liquid ink storage and supply
assembly 400 that is located below a melter housing 302 of the
melter assembly 300. The phase change ink melting and control
assembly 100 then includes the pre-melter assembly 200 of the
present invention for controllably containing, conditioning and
feeding solid pieces of phase change ink from the solid ink sources
22, 24, 26, 28 of the ink system 20.
[0020] As further illustrated, the pre-melter assembly 200 includes
(a) a first portion 201 having a first feeding apparatus 202 and a
first container 204 for containing and feeding solid pieces of
phase change ink. It also includes a second portion 205 having a
second container 207 and a second feeding apparatus 206 for
containing and feeding solid pieces of phase change ink to the
melter housing 302. The pre-melter assembly 200 then includes a
cooling device 210 mounted in heat exchange relationship with the
second feeding apparatus 206 for maintaining a temperature Tw of
the solid pieces of phase change ink below a melting point
temperature Tm of the solid pieces of phase change ink, thereby
preventing premature melting of the solid pieces of phase change
ink before the solid pieces reach the melter housing 302.
[0021] The first feeding apparatus 202 comprises 4 tubes 202A,
202B, 202C, 202D, one for each color CYMK of ink, and similarly the
second feeding apparatus 206 comprises 4 thermally conductive pipes
206A, 206B, 206C, 206D, one for each color CYMK of ink. The cooling
device 210 is a heat sink or heat exchanger. Each of the 4
thermally conductive pipes 206A, 206B, 206C, 206D is made for
example of aluminum. The heat sink or heat exchanger 210 ensures
that the solid ink pieces of phase change ink do not pre-maturely
melt in the second feeding apparatus 206, by keeping the surface
temperature Tw of the solid ink pieces at about 60.degree. C. for
example, which is below their melting temperature Tm of 110.degree.
C. The melter assembly 300, as well as the molten liquid ink
storage and control assembly 400, which are all located below the
pre-melter assembly 200, generate and convect heat vertically at
120.degree. C. for example, and directly up to the aluminum thermal
pipes 206A, 206B, 206C, 206D. The heat exchanger 210 is therefore
very necessary.
[0022] The first container 204 is a stationary basket that is
mounted to a portion of the frame 105 of the machine 10. At the
bottom of the stationary or upper basket 204, there is a flapper
door 212 that closes or shuts the first feeding apparatus 202 when
a drawer 214 containing the rest of the ink storage and control
assembly 100 is pulled out and separated from the first portion
201. This flapper door 212 prevents the solid ink pieces from
falling out into the bottom of the machine. The flapper door 212
opens again when the drawer 214 is pushed back into place. The
stationary upper basket 204 mounts to the frame 105 and stays
behind as the drawer 214 is opened. The lower container or basket
207 is mounted in the drawer 214 with the rest of the phase change
ink melting and control assembly 100.
[0023] The heat sink 210 has a perimeter of about 100 inches of fin
length and about 100 square inches of fin area for providing enough
cooling (about 65.degree. C. delta T) to keep the solid ink pieces
from pre-melting in the feed hole or pipes 206A, 206B, 206C, 206D
prior to reaching the melter housing 302. This is important because
any surfaces that are hotter than 70.degree. C. and contact the
solid ink pieces will cause the solid ink pieces to start to melt
and thus create a blockage across the hole or pipes 206A, 206B,
206C, 206D. The heat sink 210 is thus designed to keep such contact
surfaces below 60.degree. C. The heat convection from the
subassemblies below itself produces a temperature of 115.degree. C.
at steady state. The thermal impedance of the heat sink 210 is 1.28
C/watt.
[0024] As can be seen, there has been provided a pre-melter
assembly for containing, conditioning and feeding solid pieces of
phase change ink into a melter housing in a phase change ink image
producing machine. The pre-melter assembly includes (a) a first
portion having a first feeding apparatus and a first container for
containing and feeding solid pieces of phase change ink. It also
includes a second portion having a second container and a second
feeding apparatus for containing and feeding solid pieces of phase
change ink to a melter housing. The pre-melter assembly then
includes a cooling device mounted in heat exchange relationship
with the second feeding apparatus for maintaining a temperature Tw
of the solid pieces of phase change ink below a melting point
temperature Tm of the solid pieces of phase change ink, thereby
preventing premature melting of the solid pieces of phase change
ink before the solid pieces reach the melter housing.
[0025] While the embodiment of the present invention disclosed
herein is preferred, it will be appreciated from this teaching that
various alternative, modifications, variations or improvements
therein may be made by those skilled in the art, which are intended
to be encompassed by the following claims:
* * * * *