U.S. patent application number 11/873531 was filed with the patent office on 2008-02-14 for pinion roller drive for recording apparatus.
Invention is credited to Mark D. Bedzyk, Jeffery R. Hawver.
Application Number | 20080036142 11/873531 |
Document ID | / |
Family ID | 36653385 |
Filed Date | 2008-02-14 |
United States Patent
Application |
20080036142 |
Kind Code |
A1 |
Bedzyk; Mark D. ; et
al. |
February 14, 2008 |
PINION ROLLER DRIVE FOR RECORDING APPARATUS
Abstract
An apparatus for recording an image onto a sheet medium has an
entrance drive roller paired with a corresponding entrance pressure
roller to form an entrance nip for transporting the sheet medium
into an image recording section. The image recording section has a
write head for recording onto a portion of the sheet medium being
transported between the entrance nip and exit nip. The exit nip is
formed by a drive roller paired with a corresponding exit pressure
roller for transporting the sheet medium out from the image
recording section. A motor provides rotary motion to a pinion
roller mechanically coupled to the entrance and exit drive rollers.
A loading mechanism provides a loading force to nest the pinion
roller into rotational contact against a portion of the entrance
and exit drive rollers.
Inventors: |
Bedzyk; Mark D.; (Pittsford,
NY) ; Hawver; Jeffery R.; (Marion, NY) |
Correspondence
Address: |
Susan L. Parulski;Patent Legal Staff
Carestream Health, Inc.
150 Verona Street
Rochester
NY
14608
US
|
Family ID: |
36653385 |
Appl. No.: |
11/873531 |
Filed: |
October 17, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11035307 |
Jan 13, 2005 |
7303345 |
|
|
11873531 |
Oct 17, 2007 |
|
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Current U.S.
Class: |
271/277 |
Current CPC
Class: |
B65H 2403/20 20130101;
B65H 2403/42 20130101; B41J 13/03 20130101; B65H 5/06 20130101;
B65H 2801/12 20130101; B65H 2404/143 20130101 |
Class at
Publication: |
271/277 |
International
Class: |
B65H 5/06 20060101
B65H005/06 |
Claims
1. An apparatus for recording an image onto a sheet medium,
comprising: an entrance drive roller paired with a corresponding
entrance pressure roller to form an entrance nip for transporting
the sheet medium into an image recording section; the image
recording section comprising a write head for recording onto a
portion of the sheet medium being transported between the entrance
nip and an exit nip; the exit nip formed by a drive roller paired
with a corresponding exit pressure roller, for transporting the
sheet medium out from the image recording section; a motor for
providing rotary motion to a pinion roller, the pinion roller
mechanically coupled to the entrance and exit drive rollers; and a
loading mechanism providing a loading force to nest the pinion
roller into rotational contact against a portion of the entrance
and exit drive rollers, wherein the loading mechanism comprises a
spring.
2. An apparatus for recording an image onto a sheet medium,
comprising: an entrance drive roller paired with a corresponding
entrance pressure roller to form an entrance nip for transporting
the sheet medium into an image recording section; the image
recording section comprising a write head for recording onto a
portion of the sheet medium being transported between the entrance
nip and an exit nip; the exit nip formed by a drive roller paired
with a corresponding exit pressure roller, for transporting the
sheet medium out from the image recording section; a motor for
providing rotary motion to a pinion roller, the pinion roller
mechanically coupled to the entrance and exit drive rollers; and a
loading mechanism providing a loading force to nest the pinion
roller into rotational contact against a portion of the entrance
and exit drive rollers, wherein the loading mechanism comprises an
electromagnet.
3. An apparatus for recording an image onto a sheet medium,
comprising: an entrance drive roller paired with a corresponding
entrance pressure roller to form an entrance nip for transporting
the sheet medium into an image recording section; the image
recording section comprising a write head for recording onto a
portion of the sheet medium being transported between the entrance
nip and an exit nip; the exit nip formed by a drive roller paired
with a corresponding exit pressure roller, for transporting the
sheet medium out from the image recording section; a motor for
providing rotary motion to a pinion roller, the pinion roller
mechanically coupled to the entrance and exit drive rollers; a
loading mechanism providing a loading force to nest the pinion
roller into rotational contact against a portion of the entrance
and exit drive rollers; and a counter roller coupling the exit
drive roller with the entrance drive roller, wherein the counter
roller is subject to an electromagnetic loading force or subject to
a spring loading force.
4. An apparatus according to claim 1 further comprising a motor
pinion assembly for constraining the motor body with respect to its
rotational axis, the motor pinion assembly comprising: a) a bracket
coupled to the motor body, comprising (i) a first arm extending
away from the rotational axis in a first direction; (ii) a second
arm extending away from the rotational axis in a second direction,
opposite the first direction with respect to the rotational axis of
the motor; b) a base for seating the bracket along its first and
second arms, comprising: (i) a first seat for supporting the first
arm of the bracket at a constraining member, supporting a portion
of the motor weight thereby; and (ii) a second seat for supporting
the second arm of the bracket at a counter force providing element,
and the counter force providing element thereby supporting the
remaining portion of the motor weight, wherein the counter force
providing element comprises a spring.
5. A method for driving a pair of drive rollers for transporting a
sheet medium, the method comprising: a) coupling each drive roller
with a corresponding pressure roller for providing a nip for
transporting the sheet medium; b) applying a magnetic force to a
pinion roller to nest the pinion roller against at least a portion
of each drive roller; and c) rotating the pinion roller.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a Divisional of commonly-assigned copending U.S.
patent application Ser. No. 11/035,307, filed Jan. 13, 2005,
entitled PINION ROLLER DRIVE FOR RECORDING APPARTUS by Bedzyk et
al., which issued on DATE as U.S. Pat. No. ______.
FIELD OF THE INVENTION
[0002] This invention generally relates to sheet media transport
apparatus and more particularly relates to an image recording
apparatus with a precision media transport apparatus that uses a
dual nip system having precision drive roller motion provided by a
pinion drive.
BACKGROUND OF THE INVENTION
[0003] Nip-fed sheet media transport systems using paired rollers
are widely used in various printing applications. In a nip-fed
system, a drive roller is pressed against a backing roller to form
a nip and provides drive motion at the nip. A nip-fed transport can
be engineered to perform with a suitable degree of accuracy in
devices such as printers and office copiers. However, conventional
nip-fed media transport mechanisms do not provide sufficient
precision for imaging applications that require high resolution.
For example, many types of medical imaging apparatus print onto a
sheet of recording medium at resolutions well exceeding 600 dots
per inch. For such devices, a sheet media transport must provide
extremely accurate motion when moving the sheet through the image
recording mechanism. This problem becomes even more pronounced with
full-sheet imaging, in which little or no margin is to be provided
at the leading or trailing edges of a sheet. As is well appreciated
by those skilled in media transport arts, the dynamics of handling
and urging a sheet of recording medium through a printing mechanism
can be much more complex at the leading and trailing edges than
along more central portions of the sheet.
[0004] Dual nip apparatus provide advantages where it is necessary
to provide more precise motion control for sheet media. By using
two pairs of rollers in series along the transport path, a more
stable sheet media transport is provided, since the motion of the
medium is controlled through at least one nip at any point during
the image recording process. FIG. 1 shows, in schematic form, a
conventional dual nip transport apparatus 10 as used for a sheet of
recording medium 12. In the travel path, recording medium 12 is fed
through an entrance nip 14 formed between an entrance drive roller
16 and a pressure roller 18, then through an exit nip 24 formed
between an exit drive roller 26 and a pressure roller 28. Image
data is recorded by a printhead 56 onto recording medium 12 in an
imaging area 20 between entrance nip 14 and exit nip 24, typically
using a laser or other source of electromagnetic radiation. In
order to provide uniform speed with dual nip media transport
apparatus 10, it is necessary to couple the speed of entrance drive
roller 16 at entrance nip 14 with the speed of exit drive roller 26
at exit nip 24. The conventional method for coupling entrance and
exit drive rollers 16 and 26 is using a belt 22, as shown in FIG.
1.
[0005] While the use of belt 22 for synchronizing entrance and exit
drive rollers 16 and 26 works well in many applications, the
precision afforded by this arrangement falls short of what is
needed for high resolution imaging. Problems such as disturbance of
uniform velocity or flutter cause variation in the transport
velocity of recording medium 12, particularly during leading-edge
and trailing-edge handling intervals in which recording medium 12
is gripped only at entrance nip 14 or exit nip 16. Other problems
related to compliance and tracking render the use of belt 22 as an
unsatisfactory solution, particularly for media such as film that
is generally thicker and more rigid than paper media or for sheet
media that can vary in thickness. Furthermore, belt 22 is a wear
item that may require replacement and whose performance can be
degraded by age, usage, and dust or dirt.
[0006] There are a number of alternatives for providing rotational
motion to entrance and exit drive mechanisms. As one alternative,
either entrance drive roller 16 or exit drive roller 26 could be
directly coupled to a motor shaft, with coupling mechanisms
provided between these rollers. However, due to inherent coupling
losses and mechanical tolerances, it can be difficult to obtain a
coupling arrangement that provides highly efficient coupling with
minimum flutter. As another alternative, a third roller can be
driven by the motor and used to couple rotation to entrance and
exit rollers. While this option offers some advantages, its
implementation is complicated by the need to maintain efficient
coupling under load and to compensate for unwanted mechanical
effects caused by motor rotation.
[0007] Thus, it can be seen that there is a need for a transport
mechanism that provides precision handling of single sheet media at
a constant transport speed, allowing full sheet imaging from
leading to trailing edge.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a sheet
media transport apparatus capable of improved precision. With this
object in mind, the present invention provides an apparatus for
recording an image onto a sheet medium, comprising: a) an entrance
drive roller paired with a corresponding entrance pressure roller
to form an entrance nip for transporting the sheet medium into an
image recording section; b) an image recording section comprising a
write head for recording onto a portion of the sheet medium being
transported between the entrance nip and an exit nip; c) an exit
nip formed by a drive roller paired with a corresponding exit
pressure roller, for transporting the sheet medium out from the
image recording section; d) a motor for providing rotary motion to
a pinion roller, the pinion roller mechanically coupled to the
entrance and exit drive rollers; and e) a loading mechanism
providing a loading force to nest the pinion roller into rotational
contact against a portion of the entrance and exit drive
rollers.
[0009] It is a feature of the present invention that it employs a
coupling roller to transfer rotational energy to both driver
rollers. Unlike prior art arrangements, the coupling roller does
not form a nip or directly transport the medium, but is used to
provide continuous, smooth motion between the entrance and exit
drive rollers, each of which forms its corresponding nip with a
separate pressure roller.
[0010] It is an advantage of the present invention that it provides
a sheet media transport solution with higher mechanical coupling
stiffness than is conventionally available using belt devices. This
increased coupling stiffness, in turn, improves mechanical
resonance characteristics of the media transport apparatus of the
present invention. The apparatus and method of the present
invention minimize the need for replaceable components and provide
a self-aligning coupling, minimizing the need for synchronization
adjustment to the sheet transport apparatus.
[0011] It is an advantage of the present invention that it provides
improved velocity uniformity, with a design that inherently
averages surface noise from system components.
[0012] These and other objects, features, and advantages of the
present invention will become apparent to those skilled in the art
upon a reading of the following detailed description when taken in
conjunction with the drawings wherein there is shown and described
an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] While the specification concludes with claims particularly
pointing out and distinctly claiming the subject matter of the
present invention, it is believed that the invention will be better
understood from the following description when taken in conjunction
with the accompanying drawings, wherein:
[0014] FIG. 1 is a schematic diagram showing a conventional, prior
art, dual-nip media transport apparatus.
[0015] FIG. 2 is a perspective view of an apparatus for image
recording, using a dual-nip media transport according to the
present invention.
[0016] FIG. 3 is a perspective view showing the dual nip transport
apparatus of the present invention.
[0017] FIGS. 4A and 4B are perspective and partially exploded
views, respectively, of drive components of the dual nip media
transport.
[0018] FIG. 5 is a top view showing the dual nip media
transport.
[0019] FIG. 6 is a side view showing the dual nip media
transport.
[0020] FIG. 7 is a cutaway end view showing drive components of the
dual nip media transport.
[0021] FIG. 8 is a cutaway side view showing drive components of
the dual nip media transport.
[0022] FIG. 9 is a cutaway top view showing dual nip media
transport components.
[0023] FIG. 10 is a cutaway end view showing drive components of
the dual nip media transport.
[0024] FIG. 11 is a side view of drive mounting components for the
dual nip media transport.
[0025] FIG. 12 is a rear view of motor pinion assembly
components.
[0026] FIGS. 13A and 13B are side and front views, respectively, of
drive components in one embodiment.
[0027] FIGS. 14A and 14B are side and front views, respectively, of
drive components in an alternate embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0028] Reference is made to commonly-assigned copending U.S. patent
application Ser. No. 10/977,841, filed Oct. 29, 2004, entitled
SHEET RECORDING APPARATUS WITH DUAL NIP TRANSPORT by Hawver et al.,
the disclosure of which is incorporated herein.
[0029] The present description is directed in particular to
elements forming part of, or cooperating more directly with,
apparatus in accordance with the invention. It is to be understood
that elements not specifically shown or described may take various
forms well known to those skilled in the art.
[0030] Referring to FIG. 2, there is shown an image recording
apparatus 58 for full sheet imaging, utilizing a dual nip media
transport apparatus 30 according to an embodiment of the present
invention. A sheet of recording medium 12, transported in direction
Q, has a leading edge 32 and a trailing edge 34. Pressure rollers
18 and 28 cooperate with corresponding entrance and exit drive
rollers 16 and 26 to form entrance nip 14 and exit nip 24,
respectively. In the embodiment shown, a motor 60 provides
rotational energy to a pinion roller 40. Pinion roller 40 couples
rotation to both entrance and exit drive rollers 16 and 26 at speed
reduction wheels 42 and 44. For reference, conventional Cartesian
coordinate x, y, z axes are as shown in FIG. 2, with direction Q in
parallel with the y axis and rollers extended in the direction of
the x axis.
[0031] Imaging area 20 is in a widthwise strip of recording medium
12 between entrance and exit nips 14 and 24. Printhead 56 directs
exposure energy from a laser or other source, in a scanned fashion,
onto that portion of recording medium 12 that is within imaging
area 20. A control logic processor 62 controls the flow of image
data to printhead 56, controls operation of motor 60, which may be
provided with an encoder, and controls other internal and interface
functions of image recording apparatus, using components,
algorithms, and techniques familiar to those skilled in the
electronic imaging arts.
[0032] Referring to FIG. 3, there is shown a portion of dual nip
transport apparatus 30 without recording medium 12 or pressure
rollers 18, 28. This provides a clearer view of pinion roller 40
and the support mechanisms for driving entrance and exit drive
rollers 16 and 26. Speed reduction wheels 42, 44 are in continuous
rotational contact with pinion roller 40. The use of speed
reduction wheels 42 enables motor 60 to operate more efficiently,
running at a higher rotational speed.
Mounting Arrangement for Motor 60
[0033] Still referring to FIG. 3, a motor pinion assembly 82 is
designed to provide a number of functions in dual nip transport
apparatus 30. Pinion roller 40 must be maintained in continuous
rotational contact against speed reduction wheels 42, 44. Force is
required to nest pinion roller 40 in position against speed
reduction wheels 42, 44. At the same time, components of motor
pinion assembly 82 must counter the rotational torque of motor
60.
[0034] Referring to FIG. 4A, there is shown a cutaway perspective
view of the drive portion of dual nip transport apparatus 30 and
motor pinion assembly 82. An optional counter roller 46 may also be
provided, for reasons described subsequently. FIG. 4B shows a
partially exploded view of the components shown in FIG. 4A. Motor
60 is mounted in a mounting bracket 70 that serves as a motor body
mount. Mounting bracket 70 has extended portions: a left and right
arm 80L and 80R extending in directions away from rotational axis
R. Mounting bracket 70 fits onto a base 72 at two seats 78 and is
configured to counter the rotational torque of motor 60 and to
provide a substantially balanced support for the mass of motor 60.
A constraining member 84, spherically shaped in the embodiment
shown, provides one seat along left arm 80L. A spring 76 provides a
counter force providing element at the second seat along right arm
80R. This counter force effectively balances the weight of motor 60
in its mounting bracket 70. In the embodiment shown, spherical
constraining member 84 provides a contact surface 74 as the
interface between bracket 70 and base 72. Constraining member 84 is
captive in left arm 80L of mounting bracket 70 in the embodiment
described here; however, an equivalent component could be captive
or supported within base 72 or formed as a machined or molded
portion of mounting bracket 70, for example.
[0035] A better understanding of the design and function of motor
pinion assembly 82 in one embodiment is given by the reference top
and side views, respectively, of FIGS. 5 and 6 and the
corresponding sectional views of FIGS. 7, 8, 9, and 10 taken from
various perspectives with reference to FIGS. 5 and 6. In order to
counteract the torsional force exerted by motor 60, motor pinion
assembly 82 advantageously maintains a symmetric relationship with
the center of gravity, CG, of motor pinion assembly 82. In one
embodiment, the approximate center of gravity CG of motor pinion
assembly 82, shown most clearly in FIGS. 4B, 5, 8, and 11, is in a
substantially common plane, shown as a vertical plane, with the
points of contact at constraining member 84 and at spring 76.
Common plane V containing these points is shown in the top view of
FIG. 5 and in the side view of FIG. 11. Common plane V is
orthogonal to the axis of rotation R of motor 60. This arrangement
is advantaged for achieving the balanced weight condition just
described.
[0036] As is best shown in the sectional view of FIG. 10, spring 76
applies a force F that opposes the weight of motor pinion assembly
82 at base 72. Constraining member 84 can be captive in either
mounting bracket 70 or base 72. A Vee fitting 90, shown in FIGS. 10
and 11, provides a seat that restricts constraining member 84 from
movement in both the x-direction, that is, parallel to the axis of
rotation R and in the upward or z-direction (FIG. 4A). This, in
turn, constrains unwanted forward, backward, and vertical movement
of motor 60.
[0037] As is shown in FIG. 12, an encoder 86 may be mounted on
mounting bracket 70 for providing feedback signals on motor speed
and position.
Applying Force to Nest Pinion Roller 40
[0038] As is shown in FIG. 4A, pinion roller 40 nests between speed
reduction wheels 42 and 44 in one embodiment. Alternately, pinion
roller 40 may nest against some other portion of entrance and exit
drive rollers 16 and 26. In order to drive entrance and exit drive
rollers 16 and 26, a nesting force is applied by some type of
loading mechanism as a loading force to press pinion roller 40 into
position. FIGS. 13A and 13B show the general direction of the
nesting force N on pinion roller 40. One goal of the loading
mechanism is to apply nesting force N evenly, so that the full
contact surface of pinion roller 40 applies substantially equal
pressure at all points of contact against speed reduction wheels 42
and 44. With reference to FIG. 13A, for example, this means that
the effective nesting force applied at a contact point 41 is the
same as the effective nesting force applied at a contact point
43.
[0039] In the embodiment of FIG. 8, nesting force N is applied
directly to pinion roller 40 using an arrangement of magnets 50 as
a loading mechanism. Magnetic attraction pulls pinion roller 40
into its nesting position and maintains pinion roller 40 in
continuous contact for driving entrance and exit drive rollers 16
and 26. The use of magnets 50 as a loading mechanism is
particularly advantaged for providing an even amount of pressure
along the areas of contact, allowing nesting force N to be applied
directly to the body of pinion roller 40.
[0040] FIGS. 14A and 14B show side and front views, respectively,
of an alternative approach for applying nesting force N. Here, a
bearing 88 is used, providing a surface for application of force
using a spring apparatus of some kind (not shown) as the loading
mechanism. Those skilled in the mechanical design arts will readily
recognize that deployment of a spring as a loading mechanism
requires additional mounting hardware and may require means for
adjustment and/or replacement. However, there may be applications
for which use of a spring is an advantageous alternative.
[0041] Using the two-point balance arrangement of mounting bracket
70 within base 72, as described hereinabove, simplifies the design
task of selecting appropriate magnets 50 or spring components. By
balancing bracket 70 with respect to the center of gravity CG of
motor pinion assembly 82, substantially all of the nesting force
applied to pinion roller 40 is, in turn, applied to speed reduction
wheels 42 and 44.
[0042] The arrangement of motor pinion assembly 82 described with
reference to FIGS. 4A through 14B provides two key functions:
maintaining pinion roller 40 in continuous contact for driving
speed reduction wheels 42 and 44 of entrance and exit drive rollers
16 and 26 and preventing x-axis (R-axis) rotation of the housing of
motor 60.
[0043] There are a number of options for providing one more magnet
50. One or more stationary magnets 50 can be installed along or
within a holder such as a bar 52 (FIG. 8) to attract pinion roller
40. Alternately, pinion roller 40 could itself be magnetized and
attracted toward bar 52, where bar 52 is made of a ferromagnetic
material, to produce the same effect. Magnets 50 could be
replaceable magnets, for example. Possible types of magnet 50
include Alnico, Samarium cobalt, Neodymium Iron Boron, or ceramic,
for example. In another embodiment, magnets 50 can be
electromagnets. This arrangement would allow printer control logic
(from control logic processor 62 in FIG. 2) to apply nesting force
to pinion roller 40 only when needed.
Providing Additional Coupling Stiffness
[0044] The present invention provides a further refinement to the
use of pinion roller 40 whereby additional coupling stiffness and
reduced flutter are achieved. Even though recording medium 12 is
transported in a single direction, providing coupling stiffness in
both directions is be advantageous. That is, there is quantifiable
improvement of movement uniformity and reduction of flutter when
coupling stiffness is provided in both forward and reverse
directions. A belt could be provided to increase coupling stiffness
between entrance and exit drive rollers 16 and 26. Alternately,
counter roller 46, shown particularly in FIGS. 4A, 4B, and 7, can
be provided for this reason.
[0045] Some type of loading force is required for counter roller
46. In the embodiment of FIG. 7, counter roller 46 is nested into
position using magnetic attraction, in a manner similar to the
attraction of pinion roller 40. Otherwise, springs, bearings, and
other supporting mechanical components would be necessary to
provide a loading force to seat counter roller 46 properly into
position against at least some portions of speed reduction wheels
42 and 44 or entrance and exit drive rollers 16 and 26.
[0046] The invention has been described in detail with particular
reference to certain preferred embodiments thereof, but it will be
understood that variations and modifications can be effected within
the scope of the invention as described above, and as noted in the
appended claims, by a person of ordinary skill in the art without
departing from the scope of the invention. For example, the use of
speed reduction wheels 42 and 44 as enlarged portions of entrance
and exit drive rollers 16 and 26, although advantageous for
allowing higher motor speeds and improved torque, is optional for
the present invention. In another embodiment, pinion roller 40 is
nested directly against the main body of entrance and exit drive
rollers 16 and 26. Rollers themselves could be formed from a number
of materials, suitably selected according to roller function. In
one embodiment, for example, drive rollers 16 and 26 are
urethane-coated rollers. A combination of spring force and magnetic
or electromagnetic attraction could be used to nest pinion roller
40 into position. Multiple counter rollers 46 or a segmented
counter roller 46 could be used. One or more rollers could be
hollow, particularly where magnetic attraction is used for
nesting.
[0047] Various types of printhead 56 could be employed, such as
using lasers, LEDs, or other light sources, wherein the light
emitted may be outside the visible spectrum. Other types of
printhead, utilizing thermal or inkjet printing mechanisms, could
be used. Sheet medium 12 could be a photosensitive medium or some
other type of recording medium. Either entrance drive roller 16 or
exit drive roller 26 could serve as the driving roller in an
embodiment.
[0048] Thus, what is provided is an apparatus and method for an
image recording apparatus with a precision media transport
apparatus that uses a dual nip system having precision drive roller
motion provided using a pinion roller.
Parts List
[0049] 10 dual nip transport apparatus [0050] 12 recording medium
[0051] 14 entrance nip [0052] 16 entrance drive roller [0053] 18
pressure roller [0054] 20 imaging area [0055] 22 belt [0056] 24
exit nip [0057] 26 exit drive roller [0058] 28 pressure roller
[0059] 30 dual nip transport apparatus [0060] 32 leading edge
[0061] 34 trailing edge [0062] 40 pinion roller [0063] 41 contact
point [0064] 42 speed reduction wheels [0065] 43 contact point
[0066] 44 speed reduction wheels [0067] 46 counter roller [0068] 50
magnet [0069] 52 bar [0070] 56 printhead [0071] 58 image recording
apparatus [0072] 60 motor [0073] 62 control logic processor [0074]
70 bracket [0075] 72 base [0076] 74 contact surface [0077] 76
spring [0078] 78 seat [0079] 80L left arm [0080] 80R right arm
[0081] 82 motor pinion assembly [0082] 84 constraining member
[0083] 86 encoder [0084] 88 bearing [0085] 90 Vee fitting
* * * * *