U.S. patent application number 10/280553 was filed with the patent office on 2004-04-29 for print media coating device.
Invention is credited to Gayoso, Maximo.
Application Number | 20040079476 10/280553 |
Document ID | / |
Family ID | 32106969 |
Filed Date | 2004-04-29 |
United States Patent
Application |
20040079476 |
Kind Code |
A1 |
Gayoso, Maximo |
April 29, 2004 |
PRINT MEDIA COATING DEVICE
Abstract
One embodiment is directed to a print media coating device that
includes first and second web supplies, first and second web
take-ups, and a fuser defining a print media path therethrough. The
first web supply and the first web take-up are positioned on one
side of the media path and the second web supply and the second web
take-up are positioned on the other side of the media path opposite
the first web supply and the first web take-up. A first coating
material web runs from the first web supply, along the media path
through the fuser, to the first web take-up and a second coating
material web runs from the second web supply, along the media path
through the fuser, to the second web take-up. A first peel bar is
positioned immediately adjacent to the print media path, downstream
from the fuser on the first side of the media path. A second peel
bar is positioned immediately adjacent to the print media path
downstream from the fuser and downstream from the first peel
bar.
Inventors: |
Gayoso, Maximo; (Guadalajara
Jalisco, MX) |
Correspondence
Address: |
HEWLETT-PACKARD COMPANY
Intellectual Property Administration
P. O. Box 272400
Fort Collins
CO
80527-2400
US
|
Family ID: |
32106969 |
Appl. No.: |
10/280553 |
Filed: |
October 25, 2002 |
Current U.S.
Class: |
156/235 ;
156/238; 156/555 |
Current CPC
Class: |
B32B 37/025 20130101;
Y10T 428/24843 20150115; B32B 2310/0843 20130101; Y10T 156/1712
20150115; B32B 38/10 20130101; B32B 37/08 20130101; Y10T 156/1705
20150115; B32B 37/185 20130101; Y10T 156/1741 20150115; B32B
37/1207 20130101; Y10T 428/28 20150115; Y10T 428/14 20150115; Y10S
428/914 20130101; Y10T 156/1956 20150115 |
Class at
Publication: |
156/235 ;
156/238; 156/555 |
International
Class: |
B32B 031/04 |
Claims
What is claimed is:
1. A print media coating device, comprising: a first web supply; a
first web take-up; a second web supply; a second web take-up; a
fuser defining a print media path therethrough; the first web
supply and the first web take-up positioned on a first side of the
print media path and the second web supply and the second web
take-up positioned on a second side of the print media path
opposite the first side; a first coating material web running from
the first web supply, along the print media path through the fuser,
to the first web take-up; and a second coating material web running
from the second web supply, along the print media path through the
fuser, to the second web take-up; a first peel bar immediately
adjacent to the print media path, the first peel bar disposed along
the print media path downstream from the fuser on the first side of
the print media path; and a second peel bar immediately adjacent to
the print media path, the second peel bar disposed along the print
media path downstream from the fuser and downstream from the first
peel bar on the second side of the print media path.
2. The device of claim 1, wherein each peel bar presents a rigid
narrow line of contact with the respective coating material web
across a full width of the web.
3. The device of claim 2, wherein a distance between the line of
contact of the first peel bar and the line of contact of the second
peel bar is in the range of 20 mm to 30 mm.
4. The device of claim 1, wherein: the first web take-up, the first
peel bar and the fuser are positioned relative to one another such
that the first web bends around the first peel bar on its way to
the first web take-up; and the second web take-up, the second peel
bar and the fuser are positioned relative to one another such that
the second web bends around the second peel bar on its way to the
second web take-up.
5. The device of claim 1, further comprising a web cooler defining
a continuation of the media path therethrough downstream from the
fuser, the first and second coating material webs running from the
corresponding web supply, along the media path through the fuser
and the cooler, to the corresponding web take-up.
6. The device of claim 1, wherein the fuser comprises a pair of
rollers engagable with one another to form a fuser nip and the
fuser nip defines the media path through the fuser.
7. The device of claim 5, wherein the cooler comprises a pair of
rollers engagable with one another to form a cooler nip, the cooler
nip defining the media path through the cooler and at least one of
the rollers being cooled.
8. A print media coating device, comprising: a frame; a first web
supply spool rotatably supported by the frame proximate a first
side of a print media path; a first web take-up spool rotatably
supported by the frame proximate the first side of the print media
path downstream from the first web supply spool along a first web
path that begins at the first supply spool and ends at the first
take-up spool; a second web supply spool rotatably supported by the
frame proximate a second side of the print media path opposite the
first side; a second web take-up spool rotatably supported by the
frame proximate the second side of the print media path downstream
from the second web supply spool along a second web path that
begins at the second supply spool and ends at the second take-up
spool; a fuser supported by the frame, the fuser disposed along the
media path, along the first web path between the first supply spool
and the first take-up spool, and along the second web path between
the second supply spool and the second take-up spool; a motor
drivingly coupled to the first web take-up spool and the second web
take-up spool; the media path, the first web path and the second
web path coincident with one another through the fuser; a first
peel bar supported by the frame, the first peel bar disposed along
the media path downstream from the fuser and the first peel bar
protruding into and extending across the first web path; a second
peel bar supported by the frame, the second peel bar disposed along
the print media path downstream from the fuser and the second peel
bar protruding into and extending across the second web path; and
the media path, the first web path and the second web path
coincident with one another from the fuser to at least one of the
peel bars.
9. The device of claim 8, wherein: the media path, the first web
path and the second web path are coincident with one another from
the fuser to the first peel bar; and the media path and the second
web path but not the first web path are coincident with one another
from the fuser to the second peel bar.
10. The device of claim 8, further comprising a first web spooled
on the first web supply spool and a second web spooled on the
second web supply spool, each web having a coating film and a
carrier carrying the coating film.
11. The device of claim 8, wherein each peel bar comprises a rigid
bar extending across the print media path, the bar having a bearing
surface protruding into the respective web path, a downstream face
oriented substantially perpendicular to the plane of the print
media path, and an upstream face that extends away from the
downstream face at an angle, the upstream and downstream faces
converging at the bearing surface.
12. The device of claim 8, further comprising a web cooler defining
a continuation of the media path therethrough downstream from the
fuser and upstream from the peel bars.
13. The device of claim 8, wherein the fuser comprises a pair of
rollers engagable with one another to form a fuser nip and the
fuser nip defines the media path through the fuser.
14. The device of claim 12, wherein the cooler comprises a pair of
rollers engagable with one another to form a cooler nip, the cooler
nip defining the media path through the cooler and at least one of
the rollers being cooled.
15. A print media coating device, comprising: a frame; a first web
supply spool rotatably supported by the frame proximate a first
side of a print media path; a first web take-up spool rotatably
supported by the frame proximate the first side of the print media
path; a second web supply spool rotatably supported by the frame
proximate a second side of the print media path opposite the first
side; a second web take-up spool rotatably supported by the frame
proximate the second side of the print media path; a fuser disposed
along the media path and supported by the frame, the fuser
including a pair of rollers engagable with one another to form a
fuser nip defining the media path through the fuser; a motor
drivingly coupled to the first web take-up spool, the second web
take-up spool and at least one of the fuser rollers; and first and
second peel bars disposed opposite one another across the media
path downstream from the fuser and spaced apart from one another
along the media path such that one of the peel bars is downstream
in the media path from the other peel bar.
16. A print media coating device, comprising: a sheet of print
media; a first coating material web on one side of the sheet, the
first coating material web comprising a coating film facing the
sheet and a carrier carrying the coating film; a second coating
material web on the other side of the sheet, the second coating
material web having a coating film facing the sheet and a carrier
carrying the coating film; a fuser; a first peel bar on one side of
the sheet; a second peel bar on the other side of the sheet; and a
print media path through the fuser and between the peel bars, the
first peel bar located downstream in the print media path from the
fuser, the second peel bar located downstream in the print media
path from the first peel bar and the first peel par engaging the
carrier of the first web and the second peel bar engaging the
carrier of the second web.
17. A method for coating print media, comprising: providing first
and second coating material webs, each having a coating material
and a carrier carrying the coating material; sandwiching the print
media between the first and second coating material webs; fusing
coating material to the print media; and peeling the carrier from
the coating material on the first coating material web and then
peeling the carrier from the coating material on the second
material web.
18. The method of claim 18, wherein peeling the carrier from the
coating material on the first coating material web and then peeling
the carrier from the coating material on the second material web
comprises: initiating peeling the carrier from the coating material
on the first coating material web; and then initiating peeling the
carrier from the coating material on the second material web; and
then continuing simultaneously peeling the carrier from the coating
material on the first coating material web and peeling the carrier
from the coating material on the second material web.
19. The method of claim 18, wherein fusing comprises simultaneously
applying heat and pressure to the sandwiched coating material webs
and print media.
Description
FIELD OF THE INVENTION
[0001] The invention is directed to print media coating devices and
methods.
BACKGROUND
[0002] It is sometimes desirable to coat printed media with a film
of clear flexible material. Such coatings can be formulated and
applied to help protect the printed image, enhance the printed
image or provide a more uniform gloss level across the entire media
(including both printed and unprinted areas).
[0003] Duplex printing, in which printed images are applied to both
sides of a sheet of paper or other print media, is now very common.
Many printers, copiers, multi-function peripherals and other
printing devices offer duplex printing. Where a coating is desired
on both sides of a sheet, such as might be the case with duplex
printing, the sheet must pass twice through the coating module of a
post print finishing device--once to coat the top of the sheet and
once to coat the bottom of the sheet.
[0004] The patent application filed on Oct. 25, 2002 under Attorney
Docket No. 100202897-1 ('897) and entitled "Print Media Coating
Device and Method" describes devices and methods for simultaneously
coating both sides of printed media with a flexible film. For
conventional single side coating, as well as the new two-side
coating described in the '897 patent application, it is desirable
to use a peel bar to help separate the film carrier from the film
after the film is applied to the media. Coatings are applied to
print media by overlaying on the media a multi-layered web
containing the coating material and then applying heat and pressure
to fuse the coating material to the media. The web includes a
film/layer of coating material, a carrier (sometimes called a
backing), and a release layer in between the coating material and
the carrier.
[0005] In a conventional single side coating device such as the one
illustrated in FIG. 11, the peel bar 2 protrudes slightly into
media path 3 downstream from fuser 4 to apply pressure to coating
material web 5. Web 5 is threaded through fuser 4 from a supply
spool 6 to a take-up spool 7. Coating material web 5 and media
sheet 8 are sandwiched together through fuser 4 with the coating
material film part of web 5 facing sheet 8. Fuser 4 applies heat
and pressure to the web/sheet sandwich to affix the coating
material film to the sheet 8. The carrier portion of web 5 angles
up off peel bar 2 to take-up spool 7. The point pressure applied by
peel bar 2 to web 5 helps the carrier portion of web 5 separate
more cleanly from the coating film, now affixed to sheet 8.
[0006] In one design of the new two-side coating device, the peel
bars are placed directly opposite one another across the media path
so that each carrier is peeled away from the coating film at the
same time. During the development and testing of this design, it
was discovered that the adhesion between the carrier and the
coating film is such that each web tends to pull on the sheet as
the carrier peels away from the coating film. This pull is not
always the same on each side of the sheet. One side pulling harder
than the other tends to relieve pressure on the weak side peel bar.
This pressure relief can impede separation between the carrier and
the coating film on the weak side which can, in turn, effect the
quality of the coating film retained on that side of the sheet.
Accordingly, the present invention was developed in an effort to
maintain a more uniform pressure on each peel bar as a way to
improve carrier/coating film separation.
SUMMARY
[0007] One embodiment of the present invention is directed to a
print media coating device that includes first and second web
supplies, first and second web take-ups, and a fuser defining a
print media path therethrough. The first web supply and the first
web take-up are positioned on one side of the media path and the
second web supply and the second web take-up are positioned on the
other side of the media path opposite the first web supply and the
first web take-up. A first coating material web runs from the first
web supply, along the media path through the fuser, to the first
web take-up and a second coating material web runs from the second
web supply, along the media path through the fuser, to the second
web take-up. A first peel bar is positioned immediately adjacent to
the print media path, downstream from the fuser on the first side
of the media path. A second peel bar is positioned immediately
adjacent to the print media path downstream from the fuser and
downstream from the first peel bar.
[0008] Another embodiment of the invention is directed to a method
for coating print media that includes: providing first and second
coating material webs, each web having a coating material and a
carrier carrying the coating material; sandwiching the print media
between the first and second coating material webs; fusing coating
material to the print media; and peeling the carrier from the
coating material on the first coating material web and then peeling
the carrier from the coating material on the second coating
material web.
DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a device for simultaneously coating both
sides of a sheet of print media according to one embodiment of the
invention.
[0010] FIG. 2 illustrates a typical coating material web.
[0011] FIG. 3 illustrates a device for simultaneously coating both
sides of a sheet of print media according to one embodiment of the
invention in which the device includes cooling rollers and peel
bars.
[0012] FIG. 4 illustrates a modular coating device according to one
embodiment of the invention installed in a post print-finishing
device.
[0013] FIG. 5 is a more detailed illustration of a coating device
such as the one shown in FIG. 4.
[0014] FIG. 6 illustrates the fuser and cooler module and peel bars
of a coating device such as the one shown in FIG. 4.
[0015] FIG. 7 illustrates a modular coating device according to one
embodiment of the invention installed in a post print-finishing
device attached to a printer.
[0016] FIG. 8 is a perspective view of an upper/top side-coating
module according to one embodiment of the invention.
[0017] FIG. 9 illustrates a drive train for the driven components
of a modular coating device according to one embodiment of the
invention.
[0018] FIG. 10 is a detailed view of the peel bars shown in FIG.
6.
[0019] FIG. 11 illustrates a conventional single side coating
device.
DETAILED DESCRIPTION
[0020] FIG. 1 illustrates a device for simultaneously coating both
sides of a sheet of print media according to one embodiment of the
invention. Referring to FIG. 1, coating device 10 includes
first/top side coating material web supply and web take-up spools
12 and 14, respectively and second/bottom side coating material
supply and take-up spools 16 and 18, respectively. A first/top side
coating material web 20 runs from top supply spool 12 through a
fuser 22 to top take-up spool 14. A second/bottom side coating
material web 24 runs from bottom web supply spool 16 through fuser
22 to bottom web take-up spool 18. Webs 20 and 24 represent
generally any web that carries a coating film suitable for use with
paper and other types of print media.
[0021] FIG. 2 is a section view illustrating a typical web suitable
for use in coating device 10. Referring to FIG. 2, web 20/24
includes a layer of adhesive material 26, a layer of coating
material 28 on adhesive layer 26, a carrier 30 (or backing as it is
sometimes called) and a release layer 32 interposed between carrier
30 and coating material 28. Suitable webs include, for example, the
clear flexible film webs described in pending Hewlett-Packard
patent application Ser. No. 10/167,891, filed Jun. 11, 2002 and
entitled "Images Printed On Porous Media And Coated With A Thermal
Transfer Overcoat."
[0022] Fuser 22 represents generally any suitable device for
applying heat or pressure or both to the web/media sandwich to
cause coating 28 to bond to the paper or other print media. In the
embodiment illustrated in FIG. 1, fuser 22 includes a pair of
opposing rollers 34 and 36 that rotate against one another to form
a fuser nip 40. A conventional fuser such as the roll-type fuser
used in a laser printer may be adapted for use as fuser 22 in
coating device 10. In one example of such a fuser, which is shown
in FIG. 1 and in more detail in FIG. 6, roller 34 is constructed as
a heated fuser roller and roller 36 is constructed as a compliant
pressure roller.
[0023] Downstream from fuser 22, each web 20, 24 passes over a peel
bar 52, 54. Each peel bar 52 and 54 extends across the width of the
web and protrudes slightly into the web path. That is to say, top
take-up spool 14, top peel bar 52 and fuser 22 are positioned
relative to one another such that web 20 bends around peel bar 52
on its way to top take-up spool 12. Similarly, bottom take-up spool
18, bottom peel bar 54 and fuser 22 are positioned relative to one
another such that web 24 bends around bottom peel bar 54 on its way
to bottom take-up spool 18. Each web path 46 and 48 diverges from
media path 44 at peel bars 52 and 54 at a sharp angle, preferably
60.degree. to 130.degree. and most preferably about 90.degree., to
help carrier 30 separate more cleanly away from coating layer 28.
Peel bars 52 and 54 are not aligned directly opposite one another
across the web/media path. Rather, one peel bar is positioned
downstream from the other peel bar to help improve carrier/coating
separation.
[0024] When a coating across the full width of the paper or other
print media 42 is desired, as will typically be the case, each web
20 and 24 and the corresponding supply and take-up spools are about
the same width as the print media, as best seen in FIG. 6. Print
media sheet 42 moves through fuser 22 along a media path 44. Top
web 20 moves from top web supply spool 12 through fuser 22 to top
web take-up spool 14 along a first/top web path 46. Bottom web 24
moves from bottom web supply spool 16 through fuser 22 to bottom
web take-up spool 18 along a second/bottom web path 48. Print media
path 44 and web paths 46 and 48 converge at fuser nip 40, are
coincident with one another through fuser 22 as coating 28 from
each web is applied to the top and bottom of print media sheet 42,
and then diverge as each now spent web 20a and 24a is taken up by
take-up spools 14 and 18. The combination of heat and pressure
applied to webs 20 and 24 and media sheet 42, as they pass through
fuser nip 40, melts adhesive layers 26 (FIG. 2) into sheet 42 to
bond coating 28 to the top and bottom of the sheet 42 and softens
release layer 32 to allow carrier layer 30 to be removed more
easily from coating layer 28. Spent webs 20a and 24a, taken up on
spools 14 and 18, consist of carriers 30 and the remnants of
release layers 32.
[0025] In the coating device illustrated in FIG. 3, webs 20 and 24
and sheet 42 pass through a cooler 50 located downstream from fuser
22 and then over peel bars 52 and 54 downstream from cooler 50.
Print media path 44 and web paths 46 and 48 converge at fuser nip
40, are coincident with one another through fuser 22 and cooler 50,
and then diverge at peel bars 52 and 54 as each now spent web 20a
and 24a is taken up by take-up spools 14 and 18. Cooler 50 cools
webs 20 and 24 and sheet 42 to accelerate the curing of the bond
between the coating layers 28 and sheet 42. Accelerated curing
strengthens the bond between coating 28 and sheet 42 and allows
carrier 30 to separate more cleanly from coating 28 at peel bars 52
and 54.
[0026] In the embodiment of FIG. 3, cooler 50 is constructed as a
pair of opposing cooler rollers 56 and 58 that rotate against one
another to form a cooler nip 60. Cooler 50 may cool passively as a
heat sink, in which case cooler rollers 56 and 58 are constructed
as a relatively large mass of thermally conductive material.
Alternatively, one or both cooler rollers 56 and 58 are actively
cooled so that cooler 50 actively cools the web/sheet sandwich as
it passes between cooler rollers 56 and 58.
[0027] Downstream from cooler 50, each web 20, 24 passes over a
peel bar 52, 54. Each peel bar 52 and 54 extends across the width
of the web and protrudes slightly into the web path. Each web path
46 and 48 diverges from media path 44 at peel bars 53 and 54 at a
sharp angle, preferably 60.degree. to 130.degree. and most
preferably about 90.degree., to help carrier 30 separate more
cleanly away from coating layer 28. In the embodiment of FIG. 3,
peel bars 52 and 54 are not aligned directly opposite one another
across the web/media path. It has been discovered that the
staggered configuration shown in FIG. 3, in which one peel bar is
located downstream from the other peel bar, helps improve
carrier/coating separation.
[0028] In an alternative configuration in which the peel bars are
placed directly opposite one another, each carrier 30 is peeled
away from coating layer 28 at the same time. It was discovered
during testing of this alternative configuration that the adhesion
between carrier 30 and coating 28 is such that each web 20 and 24
tends to pull on media sheet 42 as carrier 30 peels away from
coating 28. This pull is not always the same on each side of sheet
42. One side pulling harder than the other tends to relieve
pressure on the weak side peel bar. This pressure relief can impede
separation between carrier 30 and coating 28 on the weak side that
can, in turn, affect the quality of the coating retained on that
side of sheet 42. Hence, the staggered configuration for peel bars
52 and 54 is preferred over the aligned configuration.
[0029] In this staggered configuration, media sheet 42 reaches the
upstream peel bar 54 where peeling carrier 30 from bottom web 24 is
initiated at a first point in time. As sheet 42 reaches the
downstream peel bar 52, peeling carrier 30 from top web 20 is
initiated at a second later point in time.
[0030] FIGS. 4-7 illustrate a modular coating device 62 installed
in a post-print finishing device 64 operatively coupled to a
printer 66. FIG. 5 is an enlarged view of coating device 62 and
FIG. 6 is a detailed view of the fuser/cooler module 68 of coating
device 62. Referring to FIGS. 4-7, modular coating device 62
includes an upper module 68 with components for coating the top of
each sheet 42 and a lower module 70 with components for coating the
bottom of each sheet 42. Two print media paths are provided through
post print finishing device 64. A coating media path 44 runs
through coating modules 68 and 70 and a bypass media path 45
bypasses coating modules 68 and 70. Both media paths 44 and 45
discharge sheets 42 to an output tray 72 (output tray 72 is shown
in FIG. 7) or to other downstream finishing operations.
[0031] Upper module 68 includes a first/top side coating material
web supply spool 12, a first/top side web take-up spool 14, and a
first/top side fuser and cooler unit 74. Lower module 70 includes a
second/bottom side coating material web supply spool 16, a
second/bottom side web take-up spool 18, and a second/bottom side
fuser and cooler unit 76. First/top side coating material web 20
runs from top supply spool 12 through fuser and cooler unit 74 to
top take-up spool 14 around idler rollers 78 and 80 (web 20 is
shown in FIG. 5). Second/bottom side coating material web 24 runs
from bottom web supply spool 16 through fuser and cooler unit 76 to
bottom web take-up spool 18 around idler rollers 82 and 84 (web 24
is shown in FIG. 5). Top supply and take-up spools 12, 14 and
bottom supply and take-up spools 16, 18 are positioned over one
another to achieve a vertically compact design.
[0032] An exit drive roller 86 and associated pinch roller 88
propel media sheets 42 out of coating device 62 toward output tray
72 (output tray 72 is shown in FIG. 7). Each of the rollers in
upper coating module 68 are mounted to or otherwise supported by an
upper module frame 90. Each of the rollers in lower coating module
70 are mounted to or otherwise supported by a lower module frame
92.
[0033] FIG. 8 is a perspective view of upper module 68. Module 68
and its counterpart lower module 70 are configured to slide into
and out of post print finishing device 64 to facilitate
installation, repair and replacement of the module.
[0034] Referring now to FIGS. 6 and 10, top peel bar 52 is mounted
to the housing 75 of top fuser/cooler unit 74. Bottom peel bar 54
is mounted to the housing 77 of bottom fuser/cooler unit 76. Each
peel bar 52, 54 includes a web facing surface 53, 55 as shown in
FIG. 10. Rigid peel bars with a narrow line of contact against
coating webs 20 and 24 are preferred. Hence, in the configuration
shown in the drawings, web facing surfaces 53 and 55 are beveled
away from the web enough that peel bars 52 and 54 contact the web
only along a narrow edge 57, 59 on the downstream side of each peel
bar 52, 54, respectively. Because rigid housings can be used to
stiffen an otherwise more flexible bar, mounting peel bars 52 and
54 to the fuser cooler unit housings 75 and 77 allows for more
variability in the material used to construct peel bars 52 and 54
and the cross-sectional size of the peel bars. Alternatively, the
peel bars could be constructed of rigid material having a
sufficiently robust cross-section mounted on each end to frames 90
and 92. The peel bars could also be formed integral to housing 75
and 77. Other suitable configurations that allow peel bars 52 and
54 to intercept webs 20 and 24 uniformly across the width of print
media 42 are possible.
[0035] The distance along media path 44 between contact edges 57
and 59 of peel bars 52 and 54 and the extent to which peel bars 52
and 54 protrude into media path 44 may be adjusted as necessary or
desirable for a particular operating environment. For example, in a
typical business office documents are often printed on 24# paper
with an inkjet or laser printer. A suitable web for coating such
documents is nominally 12-15 .mu.m thick and carries a 3.5-3.8
.mu.m thick film of coating material. In this operating
environment, the following spacing will provide suitable
performance: approximately 30 mm between contact edges 57 and 59 of
peel bars 52 and 54, respectively and contact edges 57 and 59
protruding approximately 3 mm, into media path 44 with facing
surfaces 53, 55 beveled away from a slightly radiused or flattened
edge 57, 59, respectively. A radiused or flattened edge 57, 59 is
preferred to minimize the risk of cutting the web as it peels away
from the paper or other print media.
[0036] Peel bars 52 and 54 are configured so that the two webs
contact both peel bars at all times and so that the peel bars do
not damage or impede media sheet 42. The thickness and weight of
media sheet 42 may vary significantly. When heavier media sheets 43
are coated, peel bars 52 and 54 may be spaced further apart and may
protrude less into media path 44. It is expected that in most
operating environments, peel bars spaced apart 20-30 mm and
protruding 2-5 mm into the media path will allow for the desired
peeling.
[0037] The various components of coating device 62 may be directly
supported by the frame, such as by mounting a component directly to
the frame, or components may be indirectly supported by the frame,
such as by mounting a component to a support structure or other
component that is mounted to the frame. The frame that supports the
components may be a module frame, as in upper module frame 90 and
lower module frame 92, an overall coating device frame, or the post
print finishing device frame such as might be the case where the
coating device is not constructed of modular units that slide into
and out of the finishing device.
[0038] FIG. 9 illustrates a drive train for driven components of
modular coating device 62. In the drive train shown in FIG. 9, all
of the major components in media path 44 and web paths 46 and 48
are driven by one motor. Other drive train configurations are
possible and two or more motors could be used to drive the various
components. Referring to FIG. 9, main drive stepper motor 94 drives
main drive gear 96 clockwise. Bottom web take-up gear 98, which is
coupled to bottom web take-up spool 18, is driven clockwise off
main gear 96 through a spacer gear 100. Top web take-up gear 102,
which is coupled to top web take-up spool 14, is driven
counter-clockwise off main gear 96 through a pair of reversing
spacer gears 104 and 106. Exit drive gear 108, which is coupled to
exit drive roller 86, is driven counter-clockwise directly off main
gear 96.
[0039] Center drive gear 110, which turns coaxially with main gear
96, is driven clockwise at the urging of motor 94 through main gear
96. Top fuser roller gear 112, which is coupled to top fuser roller
34, and top cooler roller gear 114, which is coupled to top cooler
roller 56, are driven counter-clockwise off center drive gear 110.
Bottom fuser roller gear 116, which is coupled to bottom fuser
roller 36, and bottom cooler roller gear 118, which is coupled to
bottom cooler roller 58, are driven clockwise off center drive gear
110 through a center spacer gear 120.
[0040] Although not shown, the drive train illustrated in FIG. 9
may also include clutches interposed between some of the drive
elements as necessary or desirable to maintain the appropriate
relationship among moving parts. For example, electromagnetic slip
clutches should be included at take-up gears 98 and 102 to help
control the tension on top and bottom coating webs 20, 20a and 24,
24a.
[0041] While the present invention has been shown and described
with reference to the foregoing exemplary embodiments, it is to be
understood that other forms, details, and embodiments may be made
without departing from the spirit and scope of the invention that
is defined in the following claims.
* * * * *