U.S. patent application number 11/753803 was filed with the patent office on 2007-11-29 for recording apparatus.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Shinya Sonoda.
Application Number | 20070273081 11/753803 |
Document ID | / |
Family ID | 38748791 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070273081 |
Kind Code |
A1 |
Sonoda; Shinya |
November 29, 2007 |
RECORDING APPARATUS
Abstract
A recording apparatus includes a conveyance roller for conveying
a recording medium to a recording area; a drive source for
generating a drive force for driving the conveyance roller; a
feeding roller for feeding the recording medium to the conveyance
roller, the feeding roller being driven by the drive source; a
switching unit for selectively switching between a state in which
the drive force is transmitted to the feeding roller, and a state
in which the drive force is shut off from the feeding roller; and a
control unit for controlling a switching operation performed by the
switching unit under a predetermined condition. In the recording
apparatus, when a recording operation on the recording medium is
continuously performed by the recording head, if the predetermined
condition is satisfied, the control unit controls the switching
unit so that the drive force is transmitted from the drive source
to the feeding roller.
Inventors: |
Sonoda; Shinya;
(Yokohama-shi, JP) |
Correspondence
Address: |
CANON U.S.A. INC. INTELLECTUAL PROPERTY DIVISION
15975 ALTON PARKWAY
IRVINE
CA
92618-3731
US
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
38748791 |
Appl. No.: |
11/753803 |
Filed: |
May 25, 2007 |
Current U.S.
Class: |
271/114 |
Current CPC
Class: |
B65H 2403/723 20130101;
B65H 2403/72 20130101; B65H 5/06 20130101; B65H 3/0669
20130101 |
Class at
Publication: |
271/114 |
International
Class: |
B65H 3/06 20060101
B65H003/06 |
Foreign Application Data
Date |
Code |
Application Number |
May 26, 2006 |
JP |
2006-146717 |
Claims
1. A recording apparatus comprising: a conveyance roller configured
to convey a recording medium to a recording area in which recording
is performed by a recording head; a drive source configured to
generate a drive force for driving the conveyance roller; a feeding
roller configured to feed the recording medium to the conveyance
roller, the feeding roller being driven by the drive source; a
switching unit configured to selectively switch between a state in
which the drive force is transmitted from the drive source to the
feeding roller, and a state in which the drive force is shut off
from the feeding roller; and a control unit configured to control a
switching operation performed by the switching unit under a
predetermined condition, wherein even when a recording operation on
the recording medium is continuously performed by the recording
head, if the predetermined conditions are satisfied, the control
unit controls the switching unit so that the drive force is
transmitted from the drive source to the feeding roller.
2. The recording apparatus according to claim 1, wherein the
switching unit includes a solenoid configured to perform the
switching operation.
3. The recording apparatus according to claim 1, further
comprising: a carriage mounted with the recording head and
configured to make a reciprocating motion in a direction orthogonal
to a direction of conveyance of the recording medium, wherein the
switching unit includes an operation portion abutting the carriage,
and wherein the switching unit performs the switching operation in
accordance with an operation of the operation portion by the
carriage.
4. The recording apparatus according to claim 1, wherein the
switching unit performs the switching operation when the conveyance
roller is rotated by a predetermined amount in a direction opposite
to an ordinary direction of conveyance of the recording medium.
5. The recording apparatus according to claim 1, wherein the
predetermined conditions include a length of the recording medium
in the direction of conveyance of the recording medium, and
information related to the length of the recording medium in the
direction of conveyance of the recording medium is included in data
input into the recording apparatus from an external apparatus.
6. The recording apparatus according to claim 1, further
comprising: an edge detection unit configured to detect an edge of
the recording medium conveyed by the conveyance roller, wherein the
predetermined conditions include the length of the recording medium
in the direction of conveyance of the recording medium, and wherein
the information related to the length of the recording medium is
obtained by the edge detection unit which detects an edge of the
recording medium conveyed by the conveyance roller.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a recording apparatus
configured to perform recording on a recording medium.
[0003] 2. Description of the Related Art
[0004] In a conventional method for reducing time taken for
recording, a recording apparatus controls a feeding unit to reduce
a time interval between a preceding recording medium and a
subsequent recording medium.
[0005] U.S. Pat. No. 6,702,274 A1 discusses a recording apparatus
illustrated in FIGS. 12A through 12E. The recording apparatus
discussed in U.S. Pat. No. 6,702,274 A1 includes a control unit
(not shown). The control unit drives a feeding unit 111 to start
feeding another recording medium P2 before an edge detection unit
139 detects a trailing edge of a recording medium P1, which is
conveyed by a conveyance unit 140. The control unit controls
driving of the feeding unit 111 so that a leading edge of another
subsequent recording medium P2 reaches the edge detection unit 139
after the edge detection unit 139 has detected a trailing edge of
the preceding recording medium P1 .
[0006] In the conventional method discussed in U.S. Pat. No.
6,702,274 A1, in order to control driving of a feeding unit, it is
necessary to provide a drive source separately and respectively to
a feeding unit and a conveyance unit. However, with respect to an
inexpensive popular-priced recording apparatus, it is difficult to
provide a drive source to both of a feeding unit and a conveyance
unit, in terms of the manufacturing cost.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a recording apparatus
whose manufacturing cost is low and which can reduce time taken for
recording.
[0008] According to an aspect of the present invention, a recording
apparatus includes: a conveyance roller configured to convey a
recording medium to a recording area in which recording is
performed by a recording head; a drive source configured to
generate a drive force for driving the conveyance roller, a feeding
roller configured to feed the recording medium to the conveyance
roller, the feeding roller being driven by the drive source; a
switching unit configured to selectively switch between a state in
which the drive force is transmitted from the drive source to the
feeding roller and a state in which the drive force is shut off
from the feeding roller; and a control unit configured to control
switching performed by the switching unit under a predetermined
condition. In the recording apparatus, when a recording operation
on the recording medium is continuously performed by the recording
head, if the predetermined condition is satisfied, the control unit
controls the switching unit so that the drive force is transmitted
from the drive source to the feeding roller.
[0009] Further features and aspects of the present invention will
become apparent from the following detailed description of
exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate exemplary
embodiments, features, and aspects of the invention and, together
with the description, serve to explain the principle of the
invention.
[0011] FIG. 1 illustrates a cross section of a recording apparatus
according to a first exemplary embodiment of the present
invention.
[0012] FIG. 2 illustrates a cross section of a recording apparatus
according to a first exemplary embodiment of the present
invention.
[0013] FIGS. 3A through 3C each illustrate a separation roller
using a torque limiter according to the first exemplary embodiment
of the present invention.
[0014] FIGS. 4A and 4B each illustrate a drive switching mechanism
provided to the recording apparatus illustrated in FIG. 1,
according to the first exemplary embodiment of the present
invention.
[0015] FIGS. 5A through 5D each illustrate a recording operation
performed onto a recording medium by the recording apparatus
illustrated in FIG. 1, according to the first exemplary embodiment
of the present invention.
[0016] FIGS. 6A through 6D each illustrate a recording operation
performed onto a recording medium by the recording apparatus
illustrated in FIG. 1, according to the first exemplary embodiment
of the present invention.
[0017] FIG. 7 illustrates a cross section of a recording apparatus
according to a second exemplary embodiment of the present
invention.
[0018] FIGS. 8A and 8B each illustrate a drive switching mechanism
provided to the recording apparatus illustrated in FIG. 7,
according to the second exemplary embodiment of the present
invention.
[0019] FIGS. 9A through 9D each illustrate a state in which a
recording head performs a recording operation on a preceding
recording medium P1 in a main scanning direction and a recording
medium is intermittently conveyed by a conveyance roller, and show
operation states of each roller and transmission of drive force,
according to the second exemplary embodiment of the present
invention.
[0020] FIG. 10 illustrates a drive switching mechanism provided to
the recording apparatus according to a third exemplary embodiment
of the present invention.
[0021] FIGS. 11A through 11D each illustrate a recording operation
onto a plurality of recording media that the recording apparatus
performs which includes the drive switching mechanism illustrated
in FIG. 10, according to the third exemplary embodiment of the
present invention.
[0022] FIG. 12 illustrates an operation of a feeding unit in a
conventional recording apparatus.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0023] Various exemplary embodiments, features, and aspects of the
present invention will now herein be described in detail with
reference to the drawings. It is be noted that the relative
arrangement of the components, the numerical expressions, and
numerical values set forth in these embodiments are not intended to
limit the scope of the present invention unless it is specifically
stated otherwise.
First Exemplary Embodiment
[0024] Now, a first exemplary embodiment of the present invention
will be described below. A recording apparatus according to the
first exemplary embodiment will be described below with reference
to FIGS. 1 through 4, FIGS. 5A through 5D, and FIGS. 6A through
6D.
[0025] FIGS. 1 and 2 each illustrate a cross section of the
recording apparatus according to the first exemplary embodiment.
FIGS. 3A through 3C each illustrate an example of a separation
roller using a torque limiter. FIGS. 4A and 4B each illustrate an
exemplary configuration of a drive switching mechanism provided in
the recording apparatus illustrated in FIG. 1. FIGS. 5A through 5D
and FIGS. 6A through 6D each illustrate a recording operation
performed onto a recording medium by the recording apparatus
illustrated in FIG. 1.
[0026] Referring to FIG. 1 and FIG. 2, the recording apparatus
includes for the most part a feeding unit 1 and a recording unit
20. Referring to FIG. 2, the recording apparatus includes a feeding
shaft 10 around which a feeding roller 11 for conveying a recording
medium is supported and rotated, a separation roller 12 used for
separating a recording medium, and a return lever 13 used for
preventing double-feed. In addition, the recording medium includes
a pressing plate 16 that presses a recording medium placed thereon
against the feeding roller 11 and a pressing plate spring 17 that
presses the pressing plate 16 against the feeding roller 11.
[0027] Now, an exemplary configuration of the feeding unit 1 will
be described below.
[0028] The feeding unit 1 includes an automatic feeding device
having a function for separating stacked recording medium, sheet by
sheet, and conveying the separated recording medium into a
conveyance unit. The automatic feeding device is mainly composed of
a recording medium stacking unit, feeding and separation unit, and
a double-feed prevention unit.
[0029] The recording medium stacking unit includes a recording
medium leading edge reference portion 15a and the pressing plate
16. In a so-called standby state, in which a recording medium is
not conveyed by the automatic feeding device, the pressing plate 16
is anchored at a predetermined position in a direction in which the
pressing plate 16 moves away from the feeding roller 11. At this
time, a clearance large enough for stacking a plurality of
recording media is secured between the feeding roller 11 and the
pressing plate 16. The recording medium set in this portion is
retained so that a leading edge thereof abuts the recording medium
leading edge reference portion 15a, under its own weight.
[0030] In the present exemplary embodiment, in order to reduce a
load applied during feeding, the recording medium leading edge
reference portion 15a has a rib-like shape. The pressing plate 16
rotates around its one end, and can rotate and make movement. An
operation of the pressing plate 16 is restricted by the pressing
plate spring 17 and a cam (not shown). A feeding operation is
performed by pressing and separating the pressing plate 16 against
and from the feeding roller 11 at a predetermined timing.
[0031] Now, an exemplary configuration of the feeding and
separation unit will be described below.
[0032] When the pressing plate 16 is operated at a predetermined
timing as described above, a bundle of recording media placed on
the recording medium stacking unit is pressed against the feeding
roller 11. Thus, the recording medium is pressed and the feeding
roller 11 is driven to rotate at the same time. A recording medium
placed on top of the recording medium bundle is conveyed by the
frictional force of the feeding roller 11. Because the feeding
roller 11 conveys a recording medium by its frictional force, the
feeding roller 11 can be made of a rubber having a high frictional
coefficient such as ethylene propylene diene monomer (EPDM) and
urethane foam.
[0033] The recording apparatus according to the present exemplary
embodiment includes one drive source used for conveying a recording
medium. The recording apparatus conveys and feeds a recording
medium while switching between a drive mode for conveying a
recording medium and a drive mode for feeding a recording medium.
Thus, the drive force is applied to the feeding roller 11 from the
drive source via a conveyance unit and via the drive switching
mechanism disposed between the drive source and the conveyance
unit.
[0034] Here, the frictional force generated between the feeding
roller 11 and a recording medium placed on top of the recording
medium bundle is greater than the frictional force between the
top-placed recording medium and a recording medium placed
immediately below the top-placed recording medium. Accordingly,
only the top-placed recording medium is separated and conveyed.
[0035] However, a burr can be generated at an edge portion of a
recording medium when the recording medium is cut. Furthermore,
recording media can be attached to each other by static
electricity. Moreover, a frictional coefficient of a surface of a
recording medium can be extremely large. In these cases, in order
to prevent a plurality of recording media from being fed by the
feeding roller 11 at a time, the separation roller 12, which is a
separation unit including a torque limiter, separates only a
top-placed recording medium.
[0036] The separation roller 12 is pressed against the feeding
roller 11 so that the separation roller 12 abuts a recording medium
downstream, in a direction of conveyance, from a point at which the
feeding roller 11 and the recording medium first contact each
other.
[0037] Now, an exemplary configuration of the separation roller 12
will be described below with reference to FIGS. 3A through 3C. The
separation roller 12 is mounted onto a clutch cylinder 12a and
fixed. The clutch cylinder 12a includes a rotatable clutch shaft
12b. A clutch spring 12c is wound around the clutch shaft 12b. One
winding end of the clutch spring 12c engages with the clutch
cylinder 12a.
[0038] With the above-described configuration, when the clutch
shaft 12b is anchored and the separation roller 12 and the clutch
cylinder 12a are rotated in a direction indicated by an arrow A in
FIG. 3B, the clutch spring 12c wound onto the clutch shaft 12b is
released from the clutch shaft 12b. When the separation roller 12
and the clutch cylinder 12a rotate by a predetermined angle, the
clutch shaft 12b and the clutch spring 12c relatively slide. Thus,
a predetermined level of torque can be maintained.
[0039] A surface of the separation roller 12 can be made of a
rubber or urethane foam so as to have a coefficient of friction at
a level similar to the feeding roller 11. The separation roller 12
is rotatably supported by a separation roller holder 21 (see FIG.
2), which is a separation unit supporting member. The separation
roller 12 is pressed against the feeding unit 1 by a separation
roller spring 26 (see FIG. 2).
[0040] With the above-described configuration, when no recording
medium exists between the feeding roller 11 and the separation
roller 12, the separation roller 12 is driven in accordance with
the rotation of the feeding roller 11.
[0041] The frictional force between the feeding roller 11 and a
recording medium is greater than the frictional force between the
separation roller 12 driven at a predetermined level of torque and
the recording medium. Accordingly, when one sheet of recording
medium is conveyed to a portion between the feeding roller 11 and
the separation roller 12, the recording medium is conveyed while
the separation roller 12 is being driven.
[0042] On the other hand, when two recording media are conveyed to
a portion between the feeding roller 11 and the separation roller
12, the frictional force generated between the feeding roller 11
and a recording medium on the side of the feeding roller 11 is
greater than the frictional force between the recording media. In
addition, in this case, the frictional force generated between the
recording medium on the side of the separation roller 12 and the
separation roller 12 is greater than the frictional force between
the recording media.
[0043] Accordingly, the recording media can slide each other. Thus,
only the recording medium on the side of the feeding roller 11 is
conveyed, and the recording medium existing on the side of the
separation roller 12 stays where it is and is not conveyed, while
the separation roller 12 does not rotate.
[0044] Now, an exemplary configuration of the double-feed
prevention unit will be described below.
[0045] As described above, when as many as two recording media are
conveyed to a nip portion between the feeding roller 11 and the
separation roller 12, the two recording media can be separated from
each other. However, more than two recording media can be conveyed
to the nip portion between the feeding roller 11 and the separation
roller 12, or two recording media are conveyed to the nip portion
between the feeding roller 11 and the separation roller 12 and only
the recording medium on the side of the feeding roller 11 is
completely conveyed out of the nip portion. In such a case, a next
recording medium can be conveyed when the other recording medium
still exists in the vicinity of the nip portion.
[0046] Consequently, double-feed can occur, in which a plurality of
recording media is conveyed at the same time. Therefore, the
double-feed prevention unit is provided.
[0047] The double-feed prevention unit includes the return lever
13. The double-feed prevention unit allows the return lever 13 to
enter a recording medium conveyance path during setting of
recording media or a recording standby mode, and thus prevents a
leading edge of the recording medium from accidentally entering the
back portion of the feeding device. The return lever 13 is released
and retracts from the recording medium conveyance path after a
feeding operation is started. Thus, the return lever 13 does not
interfere with traveling of the recording medium during feeding of
the recording medium.
[0048] Now, an exemplary configuration of the recording unit 20
will be described below.
[0049] The recording unit 20 includes a pinch roller holder 25, a
pinch roller 29, a conveyance roller 30, a paper discharge roller
31, a spur 32, a recording medium edge detection sensor 39, and a
carriage 5 mounted with a recording head 4. The recording unit 20
drives the carriage 5 and discharges a liquid droplet from the
recording head 4 onto the recording medium, while moving the
recording head 4 in a main scanning direction, so as to form an
image on the recording medium fed from the feeding unit 1.
[0050] An image is formed in the above-described manner and
recording media are intermittently conveyed by the conveyance
roller 30 in a sub-scanning direction orthogonal to the main
scanning direction. Thus, a recording operation on a recording
medium is performed. The recording medium edge detection sensor 39
is capable of detecting a leading edge and a trailing edge of a
recording medium. The recording medium edge detection sensor 39 can
detect the dimension of the recording medium using this
function.
[0051] Now, a path which transmits drive force from the conveyance
roller 30 to the feeding roller 11, namely, a drive switching
mechanism, will be described in detail below with reference to FIG.
4A and FIG. 4B.
[0052] The drive switching mechanism includes a solar gear 33, a
swing arm 34, a planet gear 35, an arm stopper 36, and a solenoid
36a. The solar gear 33 and the planet gear 35 are connected to each
other via the swing arm 34, which rotates around a rotational axis
of the solar gear 33.
[0053] A friction spring (not shown) is provided between the solar
gear 33 and the swing arm 34. Under the friction caused by the
friction spring, the swing arm 34 oscillates in the same direction
as the direction of rotation of the solar gear 33. That is, when
the solar gear 33 rotates clockwise, the swing arm 34 is also
oscillated clockwise. At this time, the planet gear 35 separates
from a control gear 41 to be disengaged from each other. As a
result, transmission of drive force to a feed roller gear 38, which
is provided at one end of the feeding shaft 10, is shut off.
[0054] On the other hand, when the solar gear 33 rotates
counterclockwise, the swing arm 34 is also oscillated
counterclockwise. At this time, the planet gear 35 engages with the
control gear 41. As a result, the drive force is transmitted to the
feed roller gear 38 provided at one end of the feeding shaft
10.
[0055] As described above, the swing arm 34 oscillates according to
the direction of rotation of the solar gear 33, so that switching
between transmission and non-transmission of the drive force to the
feed roller gear 38, namely, to the feeding roller 11 can be
performed.
[0056] However, in this state, when a recording medium conveyance
operation is being performed during the recording operation, that
is, when the conveyance roller 30 is rotated in a direction of
conveyance of a recording medium (namely, counterclockwise), the
solar gear 33 rotates counterclockwise. Accordingly, with the
oscillation of the swing arm 34, a drive force is transmitted to
the control gear 41. As a result, a mechanism controlled by the
control gear 41, for example, the pressing plate 16 and the return
lever 13 undesirably continue to operate during the recording
operation.
[0057] Therefore, in the present exemplary embodiment, after the
feeding operation is completed and the processing shifts to the
recording operation, the arm stopper 36 can be rotated by the
solenoid 36a at an arbitrary timing in order to restrict the
oscillation of the swing arm 34. The arm stopper 36 powers on and
off the solenoid 36a. Thus, the arm stopper 36 can allow and
restrict the oscillation operation of the swing arm 34.
[0058] As illustrated in FIG. 4A, when power is shut off from the
solenoid 36a and a restriction surface 36b of the arm stopper 36
abuts a retaining portion 34a of the swing arm 34, the drive force
is shut off. On the other hand, as illustrated in FIG. 4B, when
power is supplied to the solenoid 36a and the restriction surface
36b of the arm stopper 36 is retracted from the retaining portion
34a of the swing arm 34, a drive force can be transmitted.
[0059] An operation for returning the drive switching mechanism
from a state illustrated in FIG. 4B to the state illustrated in
FIG. 4A after the feeding operation is completed and the processing
shifts to the recording operation, is performed in a manner
described below. First, the conveyance roller 30 is rotated just a
little in a direction opposite to the recording medium conveyance
direction. Thus, the swing arm 34 is oscillated clockwise as in
FIG. 4, and the planet gear 35 is disengaged from the control gear
41. Then, power is shut off from the solenoid 36a to make the
restriction surface 36b of the arm stopper 36 abut the retaining
portion 34a of the swing arm 34.
[0060] Now, the recording operation performed by the recording
apparatus according to the present exemplary embodiment for
recording on a plurality of recording media will be described below
with reference to FIGS. 5A through 5D and FIGS. 6A through 6D.
[0061] FIGS. 5A through 5D and FIGS. 6A through 6D show that a
preceding recording medium P1 is subjected to the recording
operation by the recording head 4 in the main scanning direction
and the recording medium is intermittently conveyed by the
conveyance roller 30, and shows operation states of each roller and
transmission of drive force. In the schematic view illustrating
each roller and the state of transmission of drive force, a roller
and a gear are just partly engaged with each other. However, this
is just a schematic description of the rotational direction of each
component, and details of an actual configuration are different
from the description.
[0062] Referring to FIGS. 5A through 5D, "P2" denotes a subsequent
recording medium. The drive switching mechanism includes the solar
gear 33, the swing arm 34, the planet gear 35, the arm stopper 36
including the solenoid 36a, an idler gear 37, the recording medium
edge detection sensor 39, and the control gear 41.
[0063] "PL" denotes a whole length of the recording medium, and
"PT" denotes a distance from a position at which a leading edge of
the preceding recording medium P1 is detected by the recording
medium edge detection sensor 39, to a position at which the
conveyance of the recording medium P1 is completed. "PA" denotes a
distance from the recording medium edge detection sensor 39 to a
leading edge of the subsequent recording medium (designed distance
for the recording apparatus).
[0064] As illustrated in FIG. 5A, the recording operation on the
preceding recording medium P1 by the recording head 4 starts from
an upper-left end of the recording medium. When the first half of
main scanning in a line C1 is completed, the conveyance roller 30
performs the intermittent conveyance operation (line feed), and
then the recording head 4 starts a return operation of main
scanning in a line C2. This operation is repeated, and the
recording head 4 performs recording on the preceding recording
medium P1.
[0065] A control unit provided in the recording apparatus according
to the present exemplary embodiment receives a recording command
for recording on a plurality of recording media. The control unit
operates the drive switching mechanism so that the subsequent
recording medium P2 can be fed when the following determination
expression is satisfied.
(PL-PT)<PA
where "PL" denotes the whole length of a preceding recording
medium, "PT" denotes a distance corresponding to a conveyed length
of the recording medium P1, and "PA" denotes a distance from the
recording medium edge detection sensor 39, which has detected the
leading edge of the preceding recording medium P1 to a leading edge
of the subsequent recording medium.
[0066] The recording apparatus according to the present exemplary
embodiment uses, as whole length "PL" of the recording medium,
information included in the recording command or information
obtained by the recording medium edge detection sensor 39 during
the recording operation.
[0067] FIG. 5A shows that the recording operation for the return of
main scanning in a line C12 is completed. In this state, the
above-described determination expression is not satisfied.
Accordingly, the solenoid 36a of the drive switching mechanism does
not operate. Thus, the operation of the swing arm 34 is restricted
by the arm stopper 36 of the drive switching mechanism.
[0068] Accordingly, when the solar gear 33 rotates counterclockwise
according to the recording medium conveyance operation by the
conveyance roller 30, the swing arm 34 does not similarly rotate
counterclockwise as the planet gear 35 that rotates
counterclockwise. Thus, the planet gear 35 does not engage with the
next idler gear 37. The path for transmitting the drive force to
the feeding roller 11 continues to be shut off.
[0069] FIG. 5B illustrates a state after the recording operation
for the return of main scanning in the line C12 is completed and
immediately before recording for the first half of the main
scanning in a line C13 starts. At this time, with respect to the
position of the preceding recording medium P1 in the recording
apparatus, the above-described determination expression is
satisfied by the line-feed operation by the conveyance roller 30
performed after the recording operation for the return of the main
scanning in the line C12 is completed, and accordingly, the drive
switching mechanism is permitted to operate.
[0070] That is, as can be seen from the example in FIG. 5B, a
clearance equivalent to the distance expressed by "PA-(PL-PT)" is
provided between the recording medium P1 and the recording medium
P2. Accordingly, after the recording for the first half of main
scanning in the line C13 is completed and before the line-feed
operation is performed by the conveyance roller 30, the solenoid
36a releases the arm stopper 36, and thus the solar gear 33 rotates
clockwise in FIG. 5B according to the recording medium conveyance
operation by the conveyance roller 30.
[0071] Accordingly, the swing arm 34 is oscillated clockwise in
FIG. 5B, the planet gear 35 engages with the control gear 41, and
the feeding roller 11 can be driven.
[0072] The drive switching mechanism is shifted to the
above-described state, and the line-feed operation is performed by
the conveyance roller 30 after the recording in the first half of
the main scanning in the line C13 is completed, so that the feeding
roller 11 is driven as illustrated in FIG. 5C. Thus, the line-feed
operation for the preceding recording medium P1 and the feeding
operation for the subsequent recording medium P2 are performed in
cooperation with each other.
[0073] In the recording apparatus according to the present
exemplary embodiment, the conveyance roller and the feeding roller
are driven by one drive source as described above. Thus, the
feeding operation illustrated in FIG. 5C and FIG. 5D is
intermittently performed in cooperation with the intermittent
conveyance operation by the conveyance roller 30.
[0074] Now, another case will be described below with reference to
FIGS. 6A through 6D in which the transmission of the drive force to
the feeding roller 11 is started at another different timing. In
the case of the recording operation illustrated in FIGS. 6A through
6D, a margin in the recording medium on a leading edge side is
larger than the example illustrated in FIGS. 5A through 5D.
[0075] As illustrated in FIG. 6A, the recording operation on the
preceding recording medium P1 performed by the recording head 4
starts from the upper-left corner of the recording medium, just as
the example illustrated in FIGS. 5A through 5D. When the first half
of the main scanning in a line C1 is completed and then the
intermittent conveyance operation (line-feed operation) is
performed by the conveyance roller 30, the recording head 4 starts
a recording operation for return of main scanning in a line C2. The
recording head 4 repeats this operation to perform recording on the
preceding recording medium P1.
[0076] FIG. 6A shows that the recording operation for the first
half of the main scanning in a line C11 is completed. In this
state, the above-described determination expression "(PL-PT)<PA"
is not satisfied. Accordingly, the solenoid 36a in the drive
switching mechanism does not operate.
[0077] Thus, the operation of the swing arm 34 is restricted by the
solenoid 36a of the arm stopper 36 in the drive switching
mechanism. Accordingly, when the solar gear 33 rotates
counterclockwise in accordance with the recording medium conveyance
operation by the conveyance roller 30, the swing arm 34 does not
similarly rotate counterclockwise as the planet gear 35 rotates
counterclockwise.
[0078] Thus, the planet gear 35 does not engage with the next idler
gear 37. Therefore, the path for transmitting the drive force to
the feeding roller 11 continues to be shut off.
[0079] FIG. 6B illustrates a state after the recording operation
for the first half of main scanning in the line C11 is completed
and immediately before recording for the return operation of the
main scanning in the line C12 starts. At this time, with respect to
the position of the preceding recording medium P1 in the recording
apparatus, the above-described determination expression is
satisfied by the line-feed operation performed by the conveyance
roller 30 after the recording operation for the return of the main
scanning in the line C11 is completed, and accordingly, the drive
switching mechanism is permitted to operate.
[0080] That is, as can be seen from the example in FIG. 6B, a
clearance equivalent to the distance expressed by "PA-(PL-PT)" is
provided between the recording medium P1 and the recording medium
P2. Accordingly, after the recording for the return operation of
the main scanning in the line C12 is completed and before the
line-feed operation is performed by the conveyance roller 30, the
solenoid 36a releases the arm stopper 36, and thus the solar gear
33 rotates clockwise in FIG. 6B in accordance with the recording
medium conveyance operation by the conveyance roller 30.
[0081] Accordingly, the swing arm 34 is oscillated clockwise in
FIG. 6B, the planet gear 35 engages with the control gear 41, and
the feeding roller 11 can be driven via the feed roller gear
38.
[0082] The drive switching mechanism is shifted to the
above-described state, and the line-feed operation is performed by
the conveyance roller 30 after the recording for the return main
scanning in the line C12 is completed, so that the feeding roller
11 is driven as illustrated in FIG. 6B. Thus, the line-feed
operation for the preceding recording medium P1 and the feeding
operation for the subsequent recording medium P2 are performed in
cooperation with each other.
[0083] Just as described above with reference to FIGS. 5A through
5D, the feeding operation illustrated in each of FIG. 6C and FIG.
6D is intermittently performed in cooperation with the intermittent
conveyance operation by the conveyance roller 30.
[0084] When the above-described operation is performed, the
conveyance roller 30 and the feeding roller 11 are driven with one
drive source in the recording apparatus, so that the clearance
between the preceding recording medium P1 and the subsequent
recording medium P2 can be made small. Thus, time taken for
recording can be significantly shortened.
[0085] Meanwhile, if the arm stopper 36 remains released when the
above-described feeding operation is completed, mechanical portions
controlled by the feeding roller 11 and the control gear 41 are
undesirably driven during the recording operation. In order to
prevent this, as described above with reference to FIGS. 4A and 4B,
the conveyance roller 30 is rotated just a little in a direction
opposite to the recording medium conveyance direction.
[0086] Thus, the swing arm 34 is oscillated clockwise in FIGS. 4A
and 4B, so as to disengage the planet gear 35 from the control gear
41. Then, power is shut off from the solenoid 36a so as to make the
restriction surface 36b of the arm stopper 36 abut the retaining
portion 34a of the swing arm 34.
[0087] Thus, when the swing arm 34 starts to oscillate
counterclockwise in FIG. 4A and FIG. 4B in accordance with the
rotation of the conveyance roller 30 in the recording medium
conveyance direction, that is, in accordance with the
counterclockwise rotation operation illustrated in FIG. 4A and FIG.
4B, the planet gear 35 does not engage with the control gear 41.
Thus, transmission of the drive force to the feeding roller 11 is
shut off.
Second Exemplary Embodiment
[0088] Now, a second exemplary embodiment of the present invention
will be described below. FIG. 7 illustrates a cross section of the
recording apparatus according to the second exemplary embodiment.
In the present exemplary embodiment, as illustrated in FIG. 7, the
recording apparatus includes a trigger arm 40, instead of the arm
stopper 36 having the solenoid 36a in the first exemplary
embodiment.
[0089] A control gear 41 controls an operation of the mechanical
portions of a feeding device. In the present exemplary embodiment,
a drive force is transmitted to the feeding roller 11 via the
control gear 41. Note that components and portions in the present
exemplary embodiment having the same functions as the first
exemplary embodiment are provided with the same reference numerals
and symbols. Accordingly, a description is not repeated here.
[0090] FIGS. 8A and 8B illustrate an exemplary configuration of a
drive switching mechanism provided in the recording apparatus
illustrated in FIG. 7. As illustrated in FIG. 8A and FIG. 8B, the
trigger arm 40 includes an operation surface 40a abutting a surface
of a cam (not shown) provided in the carriage 5, and a restriction
surface 40b for restricting oscillation of the swing arm 34.
[0091] The operation surface 40a of the trigger arm 40 is pressed
downward by the cam surface of the carriage 5 (not shown) mounted
with the recording head 4, at a specific position of the recording
head 4 in the main scanning direction. Thus, the trigger arm 40,
just as the arm stopper 36 (see FIG. 4), can allow and restrict the
oscillation operation of the swing arm 34.
[0092] Within a range in which the carriage 5 mounted with the
recording head 4 operates in an ordinary recording area in the main
scanning direction, the operation surface 40a of the trigger arm 40
does not contact the cam surface (not shown) of the carriage 5.
Accordingly, as illustrated in FIG. 8A, the restriction surface 40b
of the trigger arm 40 abuts the retaining portion 34a of the swing
arm 34 so as to restrict the oscillation of the swing arm 34.
[0093] That is, when the solar gear 33 rotates counterclockwise in
FIG. 8A, the swing arm 34 does not oscillate due to restriction by
the restriction surface 40b. Thus, the planet gear 35 does not
engage with the control gear 41.
[0094] On the other hand, when the carriage 5 moves to a
predetermined position, the operation surface 40a of the trigger
arm 40 is pressed downward by the cam surface (not shown) of the
carriage 5. Then, the restriction surface 40b is disengaged from
the retaining portion 34a of the swing arm 34. In this state, the
swing arm 34 can oscillate.
[0095] That is, when the solar gear 33 rotates counterclockwise in
FIG. 8A, the swing arm 34 oscillates counterclockwise. Thus, the
planet gear 35 engages with the control gear 41, and the drive
force is transmitted to the feeding roller 11 via the feed roller
gear 38.
[0096] An operation for returning the drive switching mechanism
from a state illustrated in FIG. 8B to the state illustrated in
FIG. 8A after the feeding operation is completed and the processing
shifts to the recording operation, is performed in a manner
described below.
[0097] First, the conveyance roller 30 is rotated just a little in
a direction opposite to the recording medium conveyance direction.
Thus, the swing arm 34 is oscillated clockwise as in FIG. 4, so as
to disengage the planet gear 35 from the control gear 41. Then, the
carriage 5 is moved to a position at which the operation surface
40a of the trigger arm 40 is not pressed downward, so as to make
the restriction surface 40b of the trigger arm 40 abut the
retaining portion 34a of the swing arm 34.
[0098] As described above, the recording apparatus according to the
present exemplary embodiment utilizes the oscillation of the swing
arm 34 and the operation of the trigger arm 40 to switch between
the modes for transmitting the drive force to the feeding roller
11.
[0099] Note that the specific position of the carriage 5 in the
main scanning direction at which drive transmission mode is
switched, is located outside the recording area in which the
recording operation is performed on the recording medium.
Accordingly, when the feeding operation starts by switching the
drive force transmission mode, it is necessary to move the
recording head 4 outside the recording area in the main scanning
direction.
[0100] In the present exemplary embodiment, in order to reduce
manufacturing costs of the recording apparatus to a minimum, the
trigger arm 40 is provided only on one end of the recording medium.
Accordingly, depending on image patterns to be recorded, the timing
for starting feeding of the subsequent recording medium P2 delays
by time of one main scanning.
[0101] Now, the operation performed in this case will be described
with reference to FIGS. 9A through 9D.
[0102] FIGS. 9A through 9D show a state in which a preceding
recording medium P1 is subjected to the recording operation by the
recording head 4 in the main scanning direction and the recording
medium is intermittently conveyed by the conveyance roller 30, and
also show operation states of each roller and transmission of drive
force. In the schematic view illustrating each roller and the state
of transmission of drive force, a roller and a gear are just partly
engaged with each other. However, this is just a schematic
description of the rotational direction of each component, and
details of an actual configuration are different from this
description.
[0103] Referring to FIGS. 9A through 9D, "P2" denotes a subsequent
recording medium. The drive switching mechanism includes the solar
gear 33, the swing arm 34, the planet gear 35, the idler gear 37,
the recording medium edge detection sensor 39, and the control gear
41.
[0104] "PL" denotes the whole length of the recording medium, and
"PT" denotes a distance from a position at which a leading edge of
the preceding recording medium P1 is detected by the recording
medium edge detection sensor 39, to a position at which the
conveyance of the recording medium P1 is completed. "PA" denotes a
distance from the recording medium edge detection sensor 39 to a
leading edge of the subsequent recording medium (design distance
for the recording apparatus).
[0105] As illustrated in FIG. 9A, the recording operation on the
preceding recording medium P1 by the recording head 4 starts from
an upper-left end of the recording medium, just as in the first
exemplary embodiment. When an operation for the first half of main
scanning in a line C1 is completed, the conveyance roller 30
performs the intermittent conveyance operation (line feed), and
then the recording head 4 starts a recording operation for the
return of main scanning in a line C2. This operation is repeated so
that the recording head 4 performs recording on the preceding
recording medium P1.
[0106] A control unit provided in the recording apparatus according
to the present exemplary embodiment receives a recording command
for recording on a plurality of recording media. The control unit
operates the drive switching mechanism so that the subsequent
recording medium P2 can be fed when the following determination
expression is satisfied.
(PL-PT)<PA
where "PL" denotes the whole length of a preceding recording
medium, "PT" denotes a distance corresponding to conveyed length of
the recording medium P1, and "PA" denotes a distance from the
recording medium edge detection sensor 39, which detects the
leading edge of the preceding recording medium P1, to a leading
edge of the subsequent recording medium.
[0107] The recording apparatus according to the present exemplary
embodiment uses, as whole length "PL" of the recording medium,
information included in the recording command or information
obtained by the recording medium edge detection sensor 39 during
the recording operation.
[0108] If the above-described determination expression is not
satisfied, the operation of the swing arm 34 is restricted by the
operation of the trigger arm 40, which is the drive switching
mechanism. Accordingly, when the solar gear 33 rotates clockwise in
FIGS. 9A through 9D in accordance with the recording medium
conveyance operation by the conveyance roller 30, the swing arm 34
does not rotate clockwise in FIGS. 9A through 9D the same as the
planet gear 35 that rotates clockwise. Thus, the planet gear 35
does not engage with the next control gear 41. Thus, the path for
transmitting the drive force to the feeding roller 11 continues to
be shut off.
[0109] FIG. 9A illustrates a state after the recording operation
for the return of the main scanning in the line C12 is completed
and immediately before recording for the first half of the main
scanning in a line C13 starts. At this time, the position of the
preceding recording medium P1 in the recording apparatus satisfies
the above-described determination expression.
[0110] That is, as can be seen from the example in FIG. 9A, a
clearance equivalent to the distance expressed by "PA-(PL-PT)" is
provided between the recording medium P1 and the recording medium
P2. Thus, the drive switching mechanism is permitted to
operate.
[0111] In the first exemplary embodiment, a drive force can be
transmitted to the feeding roller 11 by switching the drive mode at
this timing. In the present exemplary embodiment, because the
trigger arm 40 is provided only at one end of the recording medium,
the drive force can be transmitted to the feeding mechanism only
during the return operation for the main scanning
(even-number-of-time-th recording operation).
[0112] Accordingly, if the above-described determination expression
is satisfied, when the operation of the recording head 4 is main
scanning in the direction in which the recording head 4 is
disengaged from the trigger arm 40, the drive force is transmitted
in the following manner. After the main scanning by the recording
head 4 is completed and the conveyance roller 30 has performed the
line-feed operation, the trigger arm 40 is operated in the
direction opposite to the main scanning direction, so as to
transmit the drive force to the feeding roller 11. FIG. 9
illustrates the state of this operation.
[0113] When the recording operation for the return of main scanning
in a line C14 is started in an ordinary recording operation, the
speed of moving the carriage 5 is reduced immediately after the
recording is completed, and then a next main scanning is
performed.
[0114] However, in the case where the drive force is transmitted
using the drive switching mechanism, that is, when it is necessary
to operate the trigger arm 40 by the carriage 5 mounted with the
recording head 4, the carriage 5 is operated as follows. As
illustrated in FIG. 9B, the moving speed of the carriage 5 is not
immediately reduced, and the carriage 5 is moved to a target
stopping position at which the trigger arm 40 is located. The
target stopping position is located outside the range of the
ordinary recording operation.
[0115] When the conveyance roller 30 performs the line-feed
operation in a state where the recording for the first half of the
main scanning in the line C14 is completed and the carriage 5
operates the trigger arm 40, the restriction surface 40b of the
trigger arm 40 disengages from the retaining portion 34a of the
swing arm 34. In this state, the swing arm 34 can oscillate. That
is, when the solar gear 33 rotates counterclockwise in FIG. 9B, the
swing arm 34 oscillates counterclockwise in FIG. 9B. Thus, the
planet gear 35 engages with the control gear 41, and the drive
force is transmitted to the feeding roller 11 via the feed roller
gear 38.
[0116] When the drive switching mechanism shifts to the
above-described state, and the line-feed operation is performed by
the conveyance roller 30 after the recording for the return
operation of the main scanning in the line C13 is completed, the
feeding roller 11 is driven as illustrated in FIG. 9C. Thus, the
line-feed operation for the preceding recording medium P1 and the
feeding operation for the subsequent recording medium P2 are
performed in cooperation with each other.
[0117] In the recording apparatus according to the present
exemplary embodiment, just as the first exemplary embodiment, the
conveyance roller 30 and the feeding roller 11 are driven by one
drive source as described above. Thus, the feeding operation in the
state illustrated in each of FIG. 9C and FIG. 9D is intermittently
performed in perfect cooperation with the intermittent conveyance
operation by the conveyance roller 30.
[0118] In the configuration of the first exemplary embodiment,
depending on image patterns to be recorded, the timing for starting
feeding of the subsequent recording medium P2 delays by a time
equivalent to one main scanning.
[0119] On the other hand, in the present exemplary embodiment, the
above-described operation is performed in the recording apparatus
in which the conveyance roller 30 and the feeding roller 11 are
driven by one drive source so that the clearance between the
preceding recording medium P1 and the subsequent recording medium
P2 can be made small. Thus, the time taken for recording can be
significantly shortened.
[0120] Furthermore, in the present exemplary embodiment, the
manufacturing cost of the recording apparatus can be reduced.
[0121] Meanwhile, if the trigger arm 40 remains released when the
above-described feeding operation is completed, mechanical portions
controlled by the feeding roller 11 and the control gear 41 are
undesirably driven during the recording operation. In order to
prevent this, as described above with reference to FIGS. 8A and 8B,
the conveyance roller 30 is rotated just a little in a direction
opposite to the recording medium conveyance direction.
[0122] Thus, the swing arm 34 is oscillated clockwise in FIGS. 8A
and 8B, so as to disengage the planet gear 35 from the control gear
41. Then, power is shut off from the solenoid 36a to make the
restriction surface 36b of the arm stopper 36 abut the retaining
portion 34a of the swing arm 34. Then, the carriage 5 is moved to a
position at which the operation surface 40a of the trigger arm 40
is not pressed downward, so as to make the restriction surface 40b
of the trigger arm 40 abut the retaining portion 34a of the swing
arm 34.
[0123] Thus, when the swing arm 34 starts to oscillate
counterclockwise in FIG. 8A and FIG. 8B in accordance with the
rotation of the conveyance roller 30 in the recording medium
conveyance direction, that is, in accordance with the
counterclockwise rotation operation illustrated in FIG. 8A and FIG.
8B, the planet gear 35 does not engage with the control gear 41.
Thus, transmission of the drive force to the feeding roller 11 is
shut off.
Third Exemplary Embodiment
[0124] Now, a third exemplary embodiment of the present invention
will be described below. FIG. 10 illustrates an exemplary
configuration of the drive switching mechanism provided in the
recording apparatus according to the third exemplary
embodiment.
[0125] Referring to FIG. 10, the drive switching mechanism includes
a spring 45, a retaining pawl 47, a ratchet 51, an engagement
protrusion 55, and a clutch pawl 58. The retaining pawl 47 is
pressed against a gear G3 by the spring 45, and thus functions as a
friction clutch.
[0126] When the conveyance roller 30 is rotated in a direction
opposite to the recording medium conveyance direction, that is,
when the conveyance roller 30 is rotated clockwise in FIG. 10, the
gear G3 rotates counterclockwise in FIG. 10. Together with the
rotation, the retaining pawl 47 is rotated by the friction clutch
counterclockwise as shown in FIG. 10.
[0127] Then, the retaining pawl 47 is disengaged from the
engagement protrusion 55. Thus, the ratchet 51 engages with the
clutch pawl 58. In this state, when the conveyance roller 30 is
rotated in the recording medium conveyance direction, that is,
counterclockwise in FIG. 10, the drive force is transmitted to the
feeding roller 11 due to the engagement between the ratchet 51 and
the clutch pawl 58.
[0128] Now, the recording operation performed by the recording
apparatus according to the present exemplary embodiment for
recording on a plurality of recording media will be described below
with reference to FIGS. 11A through 11D.
[0129] As illustrated in FIG. 11A, the recording operation on the
preceding recording medium P1 by the recording head 4, starts from
an upper-left end of the recording medium, just as in the first and
the second exemplary embodiments. When an operation for the first
half of main scanning in a line C1 is completed, the conveyance
roller 30 performs the intermittent conveyance operation (line
feed), and then the recording head 4 starts a recording operation
for return of main scanning in a line C2. This operation is
repeated so that the recording head 4 performs recording on the
preceding recording medium P1.
[0130] In this state, the ratchet 51 does not engage with the
clutch pawl 58. Thus, the path for transmitting the drive force to
the feeding roller 11 continues to be shut off.
[0131] FIG. 11A illustrates a state after the recording operation
for the return of main scanning in the line C12 is completed and
recording for the first half of main scanning in a line C13 has
started. At this time, with respect to the position of the
preceding recording medium P1 in the recording apparatus, the
determination expression "(PL-PT)<PA" is satisfied, just as the
second exemplary embodiment illustrated in FIGS. 9A through 9D.
[0132] In the present exemplary embodiment, if the recording medium
is conveyed in an opposite direction in this state, a trailing edge
of the preceding recording medium P1 and a leading edge of the
subsequent recording medium P2 can collide with each other.
Accordingly, in the present exemplary embodiment, even when the
above-described determination expression is satisfied, the ordinary
line-feed operation is performed as illustrated in FIG. 11B, so as
to perform a recording operation for the return of main scanning in
the line C14.
[0133] When the recording operation for the return of main scanning
in the line C14 is completed, the conveyance roller 30 conveys the
preceding recording medium P1 by a distance "PC" in an opposite
direction, as illustrated in FIG. 11C. Then, the retaining pawl 47
is disengaged from the engagement protrusion 55 by the friction
clutch in the drive switching mechanism. Thus, the ratchet 51
engages with the clutch pawl 58, and the drive force is transmitted
to the feeding roller 11.
[0134] Then, as illustrated in FIG. 11D, the conveyance roller 30
conveys the recording medium in a forward direction in a length
equivalent to a sum of the distance PC, in which the recording
medium is conveyed in the opposite direction in the state in FIG.
11C, and a distance in a next line-feed operation. Thus, the
recording medium P1 is positioned where the recording operation for
the return of main scanning in a line C15 is performed and the
operation for feeding the recording medium P2 starts.
[0135] In the recording apparatus according to the present
exemplary embodiment, just as in the first and the second exemplary
embodiments, the conveyance roller and the feeding roller are
driven by one drive source as described above. Thus, the feeding
operation in the state illustrated in FIG. 11D is intermittently
performed in cooperation with the intermittent conveyance operation
by the conveyance roller 30.
[0136] When the above-described feeding operation is completed, the
retaining pawl 47 of the drive switching mechanism according to the
present exemplary embodiment engages with the engagement protrusion
55 again. Thus, the ratchet 51 disengages from the clutch pawl 58.
The transmission of the drive force to the feeding roller 11 is
shut off. Accordingly, the feeding roller 11 is not driven during
the recording operation.
[0137] As described above, according to each exemplary embodiment
of the present invention, the recording apparatus can be realized
whose manufacturing cost is sufficiently low and which can reduce
time taken for recording.
[0138] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all modifications, equivalent
structures, and functions.
[0139] This application claims priority from Japanese Patent
Application No. 2006-146717 filed May 26, 2006, which is hereby
incorporated by reference herein in its entirety.
* * * * *