U.S. patent application number 10/615255 was filed with the patent office on 2005-01-13 for media duplexer with disappearing sheet barrier.
Invention is credited to Madsen, Jeffrey C..
Application Number | 20050006836 10/615255 |
Document ID | / |
Family ID | 33564523 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050006836 |
Kind Code |
A1 |
Madsen, Jeffrey C. |
January 13, 2005 |
MEDIA DUPLEXER WITH DISAPPEARING SHEET BARRIER
Abstract
A media duplexer for a printing system is disclosed, the
duplexer comprising a sheet barrier within the duplexer suspended
between upper and lower belt pulleys, wherein the sheet barrier
comprises a belt having at least two barriers separated by at least
two openings, and wherein the sheet barrier rotates about the upper
and lower belt pulleys, and retractable pinch rollers disposed at
an entry to the duplexer, wherein the retractable pinch rollers
retract when one of the at least two barriers is rotated near the
entry to the duplexer, wherein print media enters and exits the
duplexer through the at least two openings.
Inventors: |
Madsen, Jeffrey C.; (Eagle,
ID) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Family ID: |
33564523 |
Appl. No.: |
10/615255 |
Filed: |
July 8, 2003 |
Current U.S.
Class: |
271/186 |
Current CPC
Class: |
B65H 2301/3331 20130101;
B65H 29/12 20130101; B65H 2801/06 20130101; B65H 15/00
20130101 |
Class at
Publication: |
271/186 |
International
Class: |
B65H 029/00 |
Claims
1. A duplexer for a media handling system, said duplexer
comprising: a sheet barrier suspended between upper and lower
rotation points, wherein said sheet barrier comprises a belt having
at least one barrier separated by at least one opening, and wherein
said sheet barrier is configured to rotate about said upper and
lower rotation points; and retractable pinch rollers disposed at an
entry to said duplexer, wherein said retractable pinch rollers are
configured to retract when one of said at least one barrier is
rotated near said entry to said duplexer, wherein media enters said
duplexer through one of said at least one opening.
2. The media duplexer of claim 1 further comprising entry and exit
pinch rollers, wherein, when said retractable pinch rollers are
retracted, said entry pinch rollers hold said print media entering
said duplexer and said exit pinch rollers hold said print media
exiting said duplexer.
3. The media duplexer of claim 1 wherein said retractable pinch
rollers are movable into an entry position to accept said print
media entering said duplexer.
4. The media duplexer of claim 1 wherein said retractable pinch
rollers are movable into an exit position to expel said print media
exiting said duplexer.
5. The media duplexer of claim 1 wherein said upper and lower belt
pulleys rotate said sheet barrier using one of: a tractor drive; a
chain drive; a slotted belt drive; and a friction belt drive.
6. The media duplexer of claim 1 wherein said media handling system
comprises one or more of a printer, a scanner, a fax, and a
multifunction device.
7. The media duplexer of claim 1 wherein said barrier material
comprises at least one of: polyamide; fabric; plastic; and
rubber.
8. The media duplexer of claim 7 wherein said barrier material
exhibits one or more of: anti-static property; non-stick property;
rigidity across a width of said sheet barrier; and flexibility.
9. The media duplexer of claim 1 wherein said print media exits
said duplexer thru one of said at least one opening.
10. A method for accommodating two pages in a duplexer at the same
time, said duplexer having a rotating barrier disposed therein,
said rotating barrier having barrier material separated by open
gaps, said method comprising: pushing a current page into an exit
path from said duplexer through one of said open gaps; directing a
next page into an input path; rotating said barrier material
between said next page entering said duplexer and said current page
exiting said duplexer, wherein said one of said open gaps is
positioned to allow said current page to exit said duplexer;
pulling said current page completely from said duplexer; and
rotating another of said open gaps into a position opening said
exit path to said next page.
11. The method of claim 10 further comprising: pushing said next
page into said exit path.
12. The method of claim 10 further comprising: retracting a set of
retractable pinch rollers within said duplexer when said barrier
material is rotated between said next page and said current
page.
13. The method of claim 12 further comprising: pinching said set of
retractable pinch rollers when said open gaps are rotated.
14. The method of claim 12 further comprising: reversing a
direction of said set of retractable pinch rollers to change said
direction of one or more of said current page and said next
page.
15. The method of claim 12 further comprising: shifting said set of
retractable pinch rollers to an output position to expel said
current page; and shifting said set of retractable pinch rollers to
an input position to accept said next page into said duplexer.
16. A system for a changing media orientation in a media handling
system, said system having a revolving obstructer disposed therein,
said revolving obstructer having at least one opening therein, said
system comprising: means for directing a media page within said
system to an exit path through one of said at least one opening;
means for rotating said barrier material between a next page
entering said system and said current page exiting said system,
wherein one of said at least one opening is positioned to allow
said current page to exit said system; means for pulling said
current page completely from said system; and means for rotating
said at least one opening into a position exposing said exit path
to said next page.
17. The system of claim 16 further comprising: means for pushing
said next page into said exit path.
18. The system of claim 16 further comprising: means for retracting
a set of retractable pinch rollers within said system when said
barrier material is rotated between said next page and said current
page.
19. The system of claim 18 further comprising: means for pinching
said set of retractable pinch rollers when said at least one
opening is rotated.
20. The system of claim 18 further comprising: means for reversing
a direction of said set of retractable pinch rollers to change said
direction of one or more of said current page and said next
page.
21. The system of claim 18 further comprising: means for shifting
said set of retractable pinch rollers to an output position to
expel said current page; and means for shifting said set of
retractable pinch rollers to an input position to accept said next
page into said system.
22. The system of claim 16 wherein said media handling system
comprises one of a printer, a scanner, a fax, and a multifunction
unit.
23. A media handling system comprising: a first media driving
surface; a second media driving surface; and a first barrier
movable between a first position in which the first barrier is
adapted to extend between a first sheet and a second sheet while
the first sheet and the second sheet are simultaneously received
between the first media driving surface and the second media
driving surface and a second position in which the first barrier is
removed from between the first sheet and the second sheet.
24. The system of claim 23 wherein the first barrier rotates about
a plurality of axes between the first position and the second
position.
25. The system of claim 23 wherein the first media driving surface
and the second media driving surface comprise rollers.
26. The system of claim 23 wherein the first media driving surface
and the second media driving surface are movable between a first
state in which the driving surfaces pinch one of the first sheet
and the second sheet therebetween and a second state in which the
driving surfaces are spaced apart to simultaneously receive the
first sheet and the second sheet.
27. The system of claim 23 including a second barrier movable
between a third position in which the second barrier is adapted to
extend between the second sheet and a third sheet while the second
sheet and the third sheet are simultaneously received between the
first media driving surface and the second media driving surface
and a second position in which the second barrier is removed from
between the second sheet and the third sheet.
28. The system of claim 27 including a belt providing the first
barrier and the second barrier, wherein the first barrier and the
second barrier are separated by a first gap and a second gap.
29. The system of claim 23 including a belt providing the first
barrier, the belt including a gap adjacent the first barrier.
30. A duplexing method comprising: moving a first sheet of media in
a first direction while between a first media driving surface and a
second media driving surface; moving the first sheet of media in a
second opposite direction while between the first media driving
surface and the second media driving surface; moving a second sheet
of media in the first direction while between the first media
driving surface and the second media driving surface; and moving a
barrier between a first position in which the barrier is between
the first sheet and the second sheet while the first sheet and the
second sheet are simultaneously received between the first media
driving surface and the second driving surface and a second
position in which the barrier is removed from between the first
sheet and the second sheet.
31. The method of claim 30 including rotating the barrier.
32. The method of claim 31 wherein the barrier is configured to
wrap around a rotation point to form first and second portions
opposite one another on opposite sides of the rotation point and
between the first media driving surface and the second media
driving surface.
33. The method of claim 31 wherein rotating the barrier includes
rotating a belt providing the barrier and having a gap adjacent the
barrier and wherein the gap receives the second sheet while the
barrier is between the first sheet and the second sheet.
Description
FIELD OF THE INVENTION
[0001] The present invention relates, in general, to media handling
devices, and, more specifically, to media duplexers.
DESCRIPTION OF RELATED ART
[0002] Media technology has advanced considerably over the last 20
years. One popular feature, found in printing systems is duplex or
double-sided printing. Similar features may also be found in
scanning devices. Duplex printing or scanning uses a mechanism that
can physically turn the substrate or print media over. Once turned
over, an image may be placed onto or scanned from the other side of
the substrate. A method of accomplishing this task is to divert the
substrate down an opening, alley, or slot and then pulling the
sheet back out of the slot wherein the former trailing edge is now
the leading edge. Typically, a subsequent page waits until the
preceding page has completely exited this apparatus before
entering. In order to implement this process, a gap or space
between successive pieces of paper larger than the length of a page
is designed into the duplex system. This page-sized gap generally
reduces the performance of the system by half.
[0003] Image fragility typically prevents more than one page to be
in the media duplexer at any one time. Accordingly, the
aforementioned gap between successive pages is generally, at least,
page-sized. In printing processes, image fragility includes issues
such as smudging, ink transfer, sheet collisions, static build up,
and the like. If two pages were in contact while sliding by each
other, print quality would likely suffer due to transfer of ink
from one page to the other, smudging the images on either page,
having the pages collide, or building up enough static energy to
either cause a spark within the printer, potentially damaging it or
creating attraction forces on the paper that make it difficult to
handle.
BRIEF SUMMARY OF THE INVENTION
[0004] Representative embodiments of the present invention are
directed to a duplexer for a media handling system, the duplexer
comprising a sheet barrier suspended between upper and lower
rotation points, wherein the sheet barrier comprises a belt having
at least one barrier separated by at least one opening, and wherein
the sheet barrier rotates about upper and lower rotation points,
and retractable pinch rollers disposed at an entry to the duplexer,
wherein the retractable pinch rollers retract when one of the at
least one barrier is rotated near the entry to the duplexer,
wherein media enters the duplexer through one of the at least one
opening.
[0005] Additional representative embodiments of the present
invention are directed to a method for accommodating two pages in a
duplexer at the same time, the duplexer having a rotating barrier
disposed therein, the rotating barrier having barrier material
separated by an open gap, the method comprising pushing a current
page into an exit path from the duplexer through one of the open
gaps, directing a next page into an input path, rotating the
barrier material between the next page entering the duplexer and
the current page exiting the duplexer, wherein the one of the open
gaps is positioned to allow the current page to exit the duplexer,
pulling the current page completely from the duplexer, and rotating
another of the open gaps into a position opening the exit path to
the next page.
[0006] Further representative embodiments of the present invention
are directed to a system for a changing media orientation in a
media handling system, the system having a revolving obstructer
disposed therein, the revolving obstructer having at least one
opening therein, the system comprising means for directing a media
page within the system to an exit path through one of the at least
one opening, means for rotating the barrier material between a next
page entering the system and the current page exiting the system,
wherein one of the at least one opening is positioned to allow the
current page to exit the system, means for pulling the current page
completely from the system, and means for rotating the at least one
opening into a position exposing the exit path to the next
page.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is a perspective diagram illustrating a sheet
barrier configured according to one embodiment of the present
invention within a duplexing system;
[0008] FIG. 1B is a diagram detailing the sheet barrier, as shown
in FIG. 1B, and configured according to an embodiment of the
present invention laid out in a flat orientation;
[0009] FIGS. 2A-2H are a series of diagrams illustrating the
positional states of the sheet barrier, as shown in FIG. 1A and
configured according to an embodiment of the present invention,
during operation;
[0010] FIG. 3 is a perspective diagram illustrating a barrier
system configured according to another embodiment of the present
invention having one barrier and one opening;
[0011] FIG. 4 is a side-view of a chain drive operable with various
embodiments of the present invention;
[0012] FIG. 5A is a side-view of a slotted belt drive operable with
various embodiments of the present invention;
[0013] FIG. 5B is a cross-sectional view of a slotted belt drive
operable with various embodiments of the present invention showing
a belt and a slotted pulley; and
[0014] FIG. 6 is a side-view illustrating a friction drive for a
barrier system operable with various embodiments of the present
invention.
DETAILED DESCRIPTION
[0015] A barrier is disclosed that protects a page of media leaving
a duplexer from being damaged or smeared by a subsequent page
entering the duplexer at the same time. Additionally, or
alternatively, the barrier protects the subsequent page. The
barrier is in the form of a belt or sheet which may comprise a
smooth film, or other such element, which, by virtue of its
geometry and motion, repeatedly presents itself between the
entering and exiting pages or media when contact between those
pages would otherwise be inevitable. The coexistence of media in
the duplexer enables increased performance over mechanisms that
must increase page to page gaps to avoid collisions. This feature
allows the gap between successive pages to be less than one page
length, allowing better system performance. Successive pages may
coexist in a duplexing slot without colliding with, smearing, or
otherwise threatening the image quality of each other.
[0016] It should be noted that such a duplexer may be used within a
printer, a scanner, a fax, or other kind of printing or
multifunction device. The present invention is not limited to
solely a printer.
[0017] FIG. 1A is a diagram illustrating sheet barrier 10
configured according to one embodiment of the present invention
within a duplexing system. Sheet barrier 10 includes tracks 100
that fit around upper belt pulleys 101 and lower belt pulleys 102.
Sheet barrier 10 comprises sheet 103 and sheet 104 which are
bounded on both sides by opening 105. As upper belt pulleys 101 and
lower belt pulleys 102 rotate, sheet barrier 10 revolves
alternating placement of sheets 103 and 104 and openings 105.
[0018] Tracks 100 and upper and lower belt pulleys 101 and 102 may
comprise a tractor drive as illustrated in FIG. 1A, or may also
comprise any other means for running sheet barrier 10 around upper
and lower belt pulleys 101 and 102, such as by a belt drive or
other friction mechanism.
[0019] FIG. 1B is a diagram detailing sheet barrier 10, and
configured according to an embodiment of the present invention laid
out in a flat orientation. Sheet barrier 10 is shown with tracks
100 unattached to illustrate the layout of openings 105 alternating
with sheets 103 and 104 (104 not shown in FIG. 1B).
[0020] The elements shown in FIGS. 1A and 11B introduces a
"barrier" (in the form of sheets 103 and 104 of sheet barrier 10)
designed to be positioned between a page that is entering and a
page that is exiting the duplexer, and then effectively disappear
each time a page reaches the turnaround point. The "disappearance"
allows a page to exit the duplexer but then reappear on the
opposite side of the exiting page to protect it from the entering
page. The "disappearance" is accomplished in the illustrated
embodiment by virtue of openings 105 in sheet barrier 10, and upper
belt pulleys 101, which are not connected by a cross shaft (i.e.,
are supported only on the outside).
[0021] When a page of media begins to enter the duplexer, it first
encounters the material of either of sheets 103 and 104, which
forms a barrier between the entering page and an exiting page. The
entering page continues downward and soon encounters one of
openings 105, through which it enters. Before the page has reached
the bottom of the duplexer, the other one of sheets 103 and 104
begins to rise up along the backside of the page. This segment of
belt material of either of sheets 103 and 104 will then protect the
page from the next entering page.
[0022] The belt material may be chosen to interact favorably with
the imaging agent, without causing smearing. Such a material may
include a film of polyamide, a textile/fabric, or even some form or
polymer or rubber. The material may be selected to have anti-static
properties as well as a characteristic that would inhibit ink from
adhering to the surface to cause smearing or streaking.
Additionally, the material selected for sheet barrier 10 in certain
embodiments of the invention provides a flexible belt or sheet that
is still stiff enough to hold itself rigid across its width. The
width would preferably be great enough to allow the windows or
openings 105 in sheet barrier 10 to be wider than the
widest-allowed print media.
[0023] The length of sheet barrier 10 may be set at any various
number of lengths responsive to several criteria that should be
considered for proper operation. A first consideration is that
sheet barrier 10 should generally reach retractable pinch roller 21
(FIG. 2A) after the leading edge of the exiting sheet has been
engaged by exit pinch roller 22 (FIG. 2B) and after retractable
pinch roller 21 (FIG. 2C) has opened. Another consideration is that
sheet barrier 10 should generally clear retractable pinch roller 21
(FIG. 2A) before the trailing edge of a sheet entering the duplexer
has reached and is no longer engaged by entry pinch roller 20 (FIG.
2B) and before retractable pinch roller 21 close onto and engage
the entering sheet.
[0024] Still another length consideration may be that sheet barrier
10 should generally be long enough so that the leading edge of the
entering sheet does not touch the exiting sheet. Furthermore, sheet
barrier 10 should generally be long enough such that the longest
compatible substrate may be held by retractable pinch roller 21 at
its furthest reach into the duplexer without the free end of the
substrate touching lower pulley system 102.
[0025] In addition to width and length considerations, the speed of
sheet barrier 10 is an element that should generally be considered.
Sheet barrier 10, which typically rotates upward toward the input
side of the duplexer to "scoop up" incoming sheets, should
generally rotate at a speed such that sheets 103 and 104 and/or
openings 105 generally reaches the same position in a cyclic
pattern. The length of the frequency pattern should generally be
equivalent with the cycle of the substrates entering and leaving
the duplexer. Speed considerations may generally be influenced by
the size and number of sheets and/or the size and number of
openings. Furthermore, sheet barrier 10 should generally not be so
fast that it creates an undesirable aerodynamic effect on either of
the entering or exiting substrates.
[0026] FIGS. 2A-2H are a series of diagrams illustrating the
positional states of sheet barrier 10, as shown in FIG. 1A and
configured according to an embodiment of the present invention,
during operation. FIGS. 2A-2H illustrate sheet barrier 10 from a
side view as installed for operation in printer duplexer 23. FIG.
2A illustrates page 200 at the lowest point within duplexer 23. At
this point, page 200 is held by retractable pinch rollers 21, which
reverse direction to begin pulling page 200 out of duplexer 23.
Incoming page 201 is being fed into duplexer 23 by entry pinch
rollers 20, while outgoing page 202 is being removed from the
duplexing system by exit pinch rollers 22. Sheet barrier 10 is
shown with sheets 103 and 104 rotating about lower belt pulleys 102
and upper belt pulleys (not shown in FIG. 2).
[0027] FIG. 2B illustrates retractable pinch rollers 21 shifting
into an exit position to direct page 200 into exit pinch rollers
22. Sheets 103 and 104 continue to rotate with one of openings 105
allowing page 200 to exit duplexer 23. Sheet 202 is shown exiting
the system.
[0028] FIG. 2C shows retractable pinch rollers 21 retracting to
allow sheet 104 to approach upper belt pulleys 101 (FIG. 1). Page
200 has engaged exit pinch rollers 22, which allows retractable
pinch rollers 21 to retract. If retractable pinch rollers 21 were
not to retract, sheet 104 would likely collide with it, ceasing the
process.
[0029] FIG. 2D shows sheet 104 providing a barrier between page
200, exiting duplexer 23, and page 201 just entering duplexer 23.
Entry pinch rollers 20 continue directing page 201 into duplexer 23
while exit pinch rollers 22 continue pulling page 200 from duplexer
23. Sheet 104 begins to turn around upper belt pulleys 101 (FIG.
1), while sheet 103 begins to turn around lower belt pulley
102.
[0030] FIG. 2E shows sheets 103 and 104 continuing their turns,
while page 200 exits duplexer 23 pulled by exit pinch rollers 22,
and page 201 enters duplexer 23 pushed by entry pinch rollers 20.
Sheet 104 maintains itself as a barrier between pages 200 and 201.
One of opening 105 is moving up toward upper belt pulleys 101 (FIG.
1).
[0031] FIG. 2F shows page 201 entering duplexer 23 through opening
105 between sheet 104 and sheet 103 turning around lower belt
pulley 102. Retractable pinch rollers 21 remain open as sheet 104
continues to revolve around upper belt pulleys 101 (FIG. 1). While
retractable pinch rollers 21 are in an open position, entry pinch
rollers 20 continue pushing paper 201 into duplexer 23. Sheet 104
remains a barrier between page 201 and page 200 being pulled out by
exit pinch rollers 22.
[0032] FIG. 2G shows retractable pinch rollers 21 snapping back to
a pinch and also moving to the entry position around page 201 as
soon as practical after sheet 104 clears retractable pinch rollers
21. Retractable pinch rollers 21 then assist in directing page 201
further into duplexer 23. Sheet 103 rises behind page 201 in order
to provide a barrier against the subsequent pages. Page 201 is
essentially captured or contained between sheets 103 and 104 as it
enters further into duplexer 23. Page 200 continues to be moved out
of duplexer 23 by exit pinch rollers 22.
[0033] FIG. 2H shows page 201 being held and directed by
retractable pinch rollers 21 only. The trailing edge of page 201
has exited entry pinch rollers 20. Sheets 103 and 104 are
containing page 201 within duplexer 23 while exit pinch roller 22
has almost completely directed page 200 from duplexer 23. As page
201 reaches the lowest point within duplexer 23, retractable pinch
rollers 21 reverse direction and move to the exit position again,
as was illustrated and described in FIGS. 2A and 2B. The reversal
of retractable pinch roller 21 begins the exit procedure for page
201 as a new page begins its entry.
[0034] In order to accommodate transportation of the paper or media
after its trailing edge has left the pinch rollers of the entering
path and before the same edge (now the leading edge) has entered
the first pinch rollers of the exiting path, a set of otherwise
retracted pinch rollers near the top of the duplexer (retractable
pinch rollers 21 of FIG. 2) close and provide the remaining
downward and subsequent upward travel into the new path. The timing
of the closing and opening of this pinch roller is set for these
pinch rollers to be closed when the belt window or opening is
present at the retractable pinch roller location. This
configuration allows the media to enter and exit the duplexer, yet
provides the barrier for the entering and exiting media when those
media are being controlled by the entering and exiting pinch
rollers. The various embodiments of the duplexer sheet barrier as
described herein allow simultaneous entry and exit of separate
sheets into the duplexing mechanism without sheet-to-sheet contact
(and associated damage or smearing, etc.), by providing a barrier
between the entering and exiting sheets.
[0035] Although FIG. 2 illustrates sheet barrier 10 having two
barriers and two openings, other numbers of barriers and openings
may be used. FIG. 3 is a perspective diagram illustrating barrier
system 30 configured according to another embodiment of the present
invention having one barrier 304 and one opening 305. FIG. 3
illustrates barrier system 30 having tracks 300 that fit around
upper pulleys 301 and lower pulleys 302. Barrier system 30
comprises barrier 304 and opening 305. As upper pulleys 301 and
lower pulleys 302 rotate, barrier system 30 revolves causing
barrier 304 and opening 305 to alternate positions in a cyclic
fashion.
[0036] In additional embodiments of the duplexer barrier system
described herein, different drive systems for rotating the barrier
system. FIG. 4 is a side-view of chain drive 40 operable with
various embodiments of the present invention. The barriers and
openings would be rotated by moving cog 400 which engages and moves
chain 401.
[0037] FIG. 5A is a side-view of slotted belt drive 50 operable
with various embodiments of the present invention.
[0038] FIG. 5B is a cross-sectional view of slotted belt drive 50
operable with various embodiments of the present invention showing
belt 500 and slotted pulley 501. The barriers and openings are
rotated around slotted pulley 501 with the extrusion on belt 500
inserts into the slot in slotted pulley 501. This joint assists
maintaining a lateral position of the barrier system.
[0039] FIG. 6 is a side-view illustrating friction drive for a
barrier system operable with various embodiments of the present
invention. Belt 600 sits on top of roller 601 with the friction
between the two elements allows belt 600 to move when roller 601 is
rotated. Other different types of drive systems may also be used in
the embodiments of the barrier system described herein.
[0040] Although the present invention and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the invention as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure of the present invention, processes, machines,
manufacture, compositions of matter, means, methods, or steps,
presently existing or later to be developed that perform
substantially the same function or achieve substantially the same
result as the corresponding embodiments described herein may be
utilized according to the present invention. Accordingly, the
appended claims are intended to include within their scope such
processes, machines, manufacture, compositions of matter, means,
methods, or steps.
* * * * *