U.S. patent application number 12/127772 was filed with the patent office on 2009-07-30 for de-skew mechanism.
Invention is credited to Hsueh-Chou Hsu, Tien-Ho Hsu, Chen-Tsai Tsai, Chang-Lung Yu.
Application Number | 20090189338 12/127772 |
Document ID | / |
Family ID | 40898409 |
Filed Date | 2009-07-30 |
United States Patent
Application |
20090189338 |
Kind Code |
A1 |
Yu; Chang-Lung ; et
al. |
July 30, 2009 |
DE-SKEW MECHANISM
Abstract
A de-skew mechanism includes a driving shaft installed on a
frame of an image forming device and driven by a motor, an active
roller installed on the driving shaft and driven by the driving
shaft, and an idle roller driven by the active roller for driving a
medium with the active roller. A nip is formed between the active
roller and the idle roller. The de-skew mechanism further includes
a correcting member installed on the driving shaft in a rotatable
manner and located upstream of the nip for correcting skew of the
medium in a correcting position, and a restoring member connected
to the correcting member for loading torque to the correcting
member so as to drive the connecting member from the correcting
position to a releasing position where the medium pass
therethrough.
Inventors: |
Yu; Chang-Lung; (Hsinchu
City, TW) ; Tsai; Chen-Tsai; (Hsinchu City, TW)
; Hsu; Hsueh-Chou; (Hsinchu County, TW) ; Hsu;
Tien-Ho; (Hsinchu City, TW) |
Correspondence
Address: |
NORTH AMERICA INTELLECTUAL PROPERTY CORPORATION
P.O. BOX 506
MERRIFIELD
VA
22116
US
|
Family ID: |
40898409 |
Appl. No.: |
12/127772 |
Filed: |
May 27, 2008 |
Current U.S.
Class: |
271/229 ;
271/226 |
Current CPC
Class: |
B65H 9/004 20130101;
B65H 9/06 20130101; B65H 2801/06 20130101; B65H 2404/6111
20130101 |
Class at
Publication: |
271/229 ;
271/226 |
International
Class: |
B65H 9/00 20060101
B65H009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2008 |
CN |
200810026100.6 |
Claims
1. A de-skew mechanism comprising: a driving shaft installed on a
frame of an image forming device and driven by a motor; an active
roller installed on the driving shaft and driven by the driving
shaft; an idle roller driven by the active roller for driving a
medium with the active roller, a nip being formed between the
active roller and the idle roller; a correcting member installed on
the driving shaft in a rotatable manner and located upstream of the
nip for correcting skew of the medium in a correcting position; and
a restoring member connected to the correcting member for loading
torque to the correcting member so as to drive the connecting
member from the correcting position to a releasing position where
the medium pass therethrough.
2. The de-skew mechanism of claim 1 wherein the correcting member
comprises a connecting portion connected to the restoring member,
and a correcting portion for blocking the medium so as to correct
the skew of the medium.
3. The de-skew mechanism of claim 2 wherein the correcting portion
is a protrusion.
4. The de-skew mechanism of claim 2 wherein a surface of the
correcting portion for blocking the medium is a plane.
5. The de-skew mechanism of claim 1 further comprising a stopping
member for stopping rotation of the restoring member.
6. The de-skew mechanism of claim 5 wherein the stopping member is
a blocker protruding from the frame of the image forming
device.
7. The de-skew mechanism of claim 1 wherein the restoring member is
a weight.
8. The de-skew mechanism of claim 2 wherein the restoring member is
a weight.
9. The de-skew mechanism of claim 3 wherein the restoring member is
a weight.
10. The de-skew mechanism of claim 4 wherein the restoring member
is a weight.
11. The de-skew mechanism of claim 5 wherein the restoring member
is a weight.
12. The de-skew mechanism of claim 6 wherein the restoring member
is a weight.
13. The de-skew mechanism of claim 7 wherein the weight is
connected with the connecting portion integrally.
14. The de-skew mechanism of claim 8 wherein the weight is
connected with the connecting portion integrally.
15. The de-skew mechanism of claim 9 wherein the weight is
connected with the connecting portion integrally.
16. The de-skew mechanism of claim 10 wherein the weight is
connected with the connecting portion integrally.
17. The de-skew mechanism of claim 11 wherein the weight is
connected with the connecting portion integrally.
18. The de-skew mechanism of claim 12 wherein the weight is
connected with the connecting portion integrally.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a de-skew mechanism, and
more particularly, to a de-skew mechanism capable of correcting
skew of a medium effectively and without damage.
[0003] 2. Description of the Prior Art
[0004] When printing to paper with a fax machine, a printer, or a
multi-function product, a paper-feeding mechanism is utilized for
feeding paper one sheet at a time into machines so as to proceed to
faxes, printouts, copies, and so on. For preventing skew images on
print media, several methods are applied to get rid of skew feed of
print media due to skew position or tolerance.
[0005] U.S. Pat. No. 6,011,948 discloses a de-skew mechanism
applied to an image forming device. Please refer to FIG. 10 and
FIG. 11. The de-skew mechanism includes shutter members 15 and a
connecting member 16 for connecting the shutter members 15. The
de-skew mechanism is installed on a rotary shaft 18 of a conveyer
roller 13 in a rotatable manner. An end 24b of each twisted coil
spring 24 is connected to the connecting member 16. A leading edge
of a sheet S contacts with a collision surface 20a of the shutter
member 15. The sheet S forms a curved loop when pushing the shutter
members 15. The shutter members 15 correct the skewed sheet S after
being pushed by the sheet S and rotating at a predetermined angle.
When the sheet S passes through rollers, the shutter members 15
restore to initial positions by the twisted coil springs 24.
However, when the sheet S passes through the rollers, the shutter
members 15 apply improper torque to the sheet S with the twisted
coil springs 24 so that the sheet S might be damaged during being
conveyed. Besides, the de-skew mechanism installed on the rotary
shaft 18 wholly is not capable of correcting skew of the sheet due
to assembly tolerance of the rollers. When the leading edge of the
sheet S collides with the shutter members 15, it can not correct
the skewed sheet effectively as the sheet is conveyed and corrected
simultaneously.
SUMMARY OF THE INVENTION
[0006] It is therefore a primary objective of the claimed invention
to provide a de-skew mechanism capable of correcting skew of a
medium effectively and without damage for solving the
above-mentioned problem.
[0007] According to the claimed invention, a de-skew mechanism
includes a driving shaft installed on a frame of an image forming
device and driven by a motor, an active roller installed on the
driving shaft and driven by the driving shaft, and an idle roller
driven by the active roller for driving a medium with the active
roller. A nip is formed between the active roller and the idle
roller. The de-skew mechanism further includes a correcting member
installed on the driving shaft in a rotatable manner and located
upstream of the nip for correcting skew of the medium in a
correcting position, and a restoring member connected to the
correcting member for loading torque to the correcting member so as
to drive the connecting member from the correcting position to a
releasing position where the medium pass therethrough.
[0008] According to the claimed invention, the correcting member
includes a connecting portion connected to the restoring member,
and a correcting portion for blocking the medium so as to correct
the skew of the medium.
[0009] According to the claimed invention, the correcting portion
is a protrusion.
[0010] According to the claimed invention, a surface of the
correcting portion for blocking the medium is a plane.
[0011] According to the claimed invention, the de-skew mechanism
further includes a stopping member for stopping rotation of the
restoring member.
[0012] According to the claimed invention, the stopping member is a
blocker protruding from the frame of the image forming device.
[0013] According to the claimed invention, the restoring member is
a weight.
[0014] According to the claimed invention, the weight is connected
with the connecting portion integrally.
[0015] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a diagram of a de-skew mechanism according to a
preferred embodiment of the present invention.
[0017] FIG. 2 is a schematic drawing of the de-skew mechanism
according to the preferred embodiment of the present invention.
[0018] FIG. 3 is a schematic drawing of a correcting member
according to the preferred embodiment of the present invention.
[0019] FIG. 4 is a lateral view of the de-skew mechanism according
to the preferred embodiment of the present invention.
[0020] FIG. 5 to FIG. 9 are lateral views of the de-skew mechanism
in different situations according to the preferred embodiment of
the present invention.
[0021] FIG. 10 is a sectional view of a de-skew mechanism in the
prior art.
[0022] FIG. 11 is an enlarged view within A1 region in FIG. 10 of
the de-skew mechanism in the prior art.
DETAILED DESCRIPTION
[0023] Please refer to FIG. 1, FIG. 1 is a diagram of a de-skew
mechanism according to a preferred embodiment of the present
invention. A pickup roller 230 is disposed on the beginning of a
conveying path 243 of a medium M stacked on a tray 210. The pickup
roller 230 picks up the medium M from the tray 210 one sheet at a
time and conveys the medium M into the conveying path 234. An input
roller 220 conveys the medium M in a direction F along the
conveying path 243 to an active roller 246 and an idle roller 247,
and then a scan module 200 can scan the medium M. At last, an
output roller 250 conveys the scanned medium M to the tray 210. An
active roller 246, an idle roller 247, and a correcting member 244
connected to the active roller 246 are disposed on the conveying
path 243.
[0024] Please refer to FIG. 2, FIG. 2 is a schematic drawing of the
de-skew mechanism according to the preferred embodiment of the
present invention. A driving is installed on a frame of an image
forming device, such as a scanner. The active roller 246 is fixed
on the driving shaft 245 and driven by a motor (not shown in
figures). The idle rollers 247 are disposed below the active roller
246, and a nip is formed between the active roller 246 and the idle
roller 247 so as to nip the medium M. The correcting member 244 is
installed on the driving shaft 245 in a rotatable manner and
located upstream of the nip and outwards the active roller 246.
[0025] Please refer to FIG. 3, FIG. 3 is a schematic drawing of the
correcting member 244 according to the preferred embodiment of the
present invention. A driving shaft 245 is installed on a frame of
an image forming device, such as a scanner. The correcting member
244 includes opening 101 for sheathing on the driving shaft 245.
The correcting member 244 includes a correcting portion 242, which
can be a protrusion, for protruding to the conveying path 243 and
located upstream of the nip of the active roller 246 and the idle
roller 247. The correcting member 244 further includes a connecting
portion 241. The correcting portion 242 located in a correcting
position upstream of the nip of the active roller 246 and the idle
roller 247 for blocking the medium M so as to correct the skew of
the medium M. The correcting portion 242 located in a releasing
position where the medium M collides with the correcting portion
242 allows the medium M to pass through the nip of the active
roller 246 and the idle roller 247.
[0026] Please refer to FIG. 3 and FIG. 4, FIG. 4 is a lateral view
of the de-skew mechanism according to the preferred embodiment of
the present invention. The de-skew mechanism further includes a
restoring member 100, which can be a weight, connected to the
connecting portion 241 of the correcting member 244 for loading
torque to the correcting member 244 so as to drive the connecting
member 244 from the correcting position to the releasing position
where the medium M pass therethrough. The restoring member 100 can
be connected with the connecting portion 241 integrally or a
separate structure from the connecting portion 241. The material
and disposition of the restoring member 100 can be designed
according to the type of the medium M. The de-skew mechanism
further includes a stopping member 111 disposed in the rear of the
restoring member 100 and below a frame 214 for stopping rotation of
the restoring member 100. The stopping member 111 can be a blocker
protruding from the frame 214 of the image forming device.
[0027] In this embodiment, a surface of the correcting portion 242
for blocking the medium M can be a plane for contacting with the
medium M smoothly so as to correct the skew of the medium M
easily.
[0028] Please refer to FIG. 5 to FIG. 9, FIG. 5 to FIG. 9 are
lateral views of the de-skew mechanism in different situations
according to the preferred embodiment of the present invention. An
end of a leading edge of the skewed medium M contacts the surface
of the correcting portion 242 and is blocked by the correcting
portion 242. Afterwards, the other end of the leading edge of the
skewed medium M contacts the surface of the correcting portion 242
and is blocked by the correcting portion 242 so that the correcting
portion 242 can not rotate when conveying the skewed medium M
continuously until force applied for the correcting member 244 by
the medium M can overcome the torque loaded by the restoring member
100 and the weight of the correcting member 244.
[0029] The medium M driven by the input roller 220 forms a curved
loop during the conveying path 243 when pushing the correcting
portion 242. Please refer to FIG. 6, when the leading edge of the
medium M aligns the surface of the correcting portion 242, the skew
of the medium M is corrected completely. When the force applied for
the correcting member 244 by the medium M overcomes the torque
loaded by the restoring member 100 and the weight of the correcting
member 244, it drives the correcting member 244 to rotate and the
leading edge of the medium M keeps aligning the surface of the
correcting portion 242. The restoring member 100 connected to the
correcting member 244 rotates accordingly so that the torque loaded
to the correcting member 244 by the restoring member 100 is
decreasing due to decrease of a distance between the restoring
member 100 and the driving shaft 245 and resistant force applied
for the medium M by the correcting portion 242 decreases. Please
refer to FIG. 7, the leading edge of the medium M enters the nip of
the active roller 246 and the idle roller 247 and is driven by the
active roller 246 and the idle roller 247 cooperatively.
[0030] Please refer to FIG. 8 and FIG. 9, when the active roller
246 and the idle roller 247 are conveying the medium M out of the
nip of the active roller 246 and the idle roller 247 cooperatively,
the correcting member 244 rotates from the correcting position to
the releasing position. Afterwards, the active roller 246 and the
idle roller 247 conveys the deskewed medium M to the scan module
200 cooperatively and the correcting member 244 returns to the
correcting position by the restoring member 100.
[0031] The torque loaded to the correcting member 244 by the
restoring member 100 is increasing due to deviation from the
correcting position of the correcting member 244 so that the torque
drives the correcting member 244 to rotate from the releasing
position to the correcting position for next correction.
[0032] When the correcting member 244 rotates from the releasing
position to the correcting position, the correcting member 244
might rotate over the original correcting position. For preventing
it, the stopping member 111 disposed in the rear of the restoring
member 100 is utilized for stopping rotation of the restoring
member 100 properly so that the correcting member 244 can return to
the correcting position stably.
[0033] The de-skew mechanism of the present invention can be
utilized in a paper-feeding mechanism of a printer, a fax, a
multifunction product (MFP), and so on. The paper-feeding mechanism
can be a single paper-feeding mechanism or a duplex paper-feeding
mechanism. The medium can be a medium for forming images thereon,
such as paper, sheet, a photograph, and so on.
[0034] In contrast to the prior art, the de-skew mechanism of the
present invention is capable of correcting the skew of the medium
effectively as the medium is conveyed and corrected simultaneously.
Besides, the de-skew mechanism of the present invention is capable
of conveying and correcting the medium without damage.
[0035] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *