2
TRANSFER CONTROL METHOD OF CONTINUOUS PAPER AND PRINTER
[0001] The disclosure of Japanese Patent Application No.
2012-175755 filed on August 8, 2012, including specification,
5 drawings and claims is incorporated herein by reference in its
entirety.
BACKGROUND
1. Technical Field
10 [0002] An aspect of the present disclosure relates to a
printer employing a paper feed roller and a tractor as a
transfer mechanism for transferring continuous paper, and more
particularly, to a transfer control method of continuous paper
and a printer which transfers the continuous paper with high
15 precision.
2. Related Art
[0003] Heretofore, in printers capable of printing
continuous paper with sprocket holes (engagement holes) formed
on both ends thereof, a tractor and a paper feed roller are
20 used as a transfer mechanism for transferring the continuous
paper. The tractor includes tractor pins (engagement portions)
which can be inserted into the sprocket holes formed along a
longitudinal direction of the continuous paper, a tractor belt
with the tractor pins formed on its outer circumference at
25 certain intervals, and a drive sprocket and a driven sprocket
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with the tractor belt mounted therebetween. The paper feed
roller is disposed between a printing position and the tractor.
[0004] A printer including a tractor and a paper feed
roller is disclosed in JP-A-2011-168365. The printer disclosed
5 in JP-A-2011-168365 transfers the continuous paper by use of
the tractor as a main feed unit until a leading end of the
continuous paper fed from the tractor side is delivered to the
paper feed roller, and the paper feed roller as the main feed
unit after the continuous paper is delivered to the paper feed
10 roller. Using the paper feed roller as the main feed unit
during printing is preferable to the high precise printing.
[0005] Further, the printer disclosed in JP-A-2011-168365
controls a transfer amount of the continuous paper by
detecting a rotational amount of the paper feed roller when
15 the paper feed roller is used as the main feed roller. If the
continuous paper slips on the paper feed roller due to the
increased transfer load of the continuous paper, the actual
feeding amount is decreased relative to the actual feeding
amount (set feeding amount) which can be calculated from the
20 rotational amount of the paper feed roller, which creates a
transfer error. Accordingly, in the printer disclosed in JP-A-
2011-168365, the actual feeding amount of the continuous paper
is calculated by detecting a driven amount of the tractor
whenever the printing corresponding to one page is performed,
25 and a difference between the calculated set feeding amount and
4
the calculated actual feeding amount is calculated from the
rotational amount of the paper feed roller. When the
continuous paper is fed to a next page, the set feeding amount
is compensated by the amount to eliminate the difference, and
5 the rotational amount of the paper feed roller is controlled
according to a compensation value.
[0006] As described in the printer disclosed in JP-A-2011-
168365, the transfer control method can realize the high
precise printing, since the paper feed roller is used as the
10 main feed roller during printing. Further, the transfer
precision can be improved, since the feeding amount to feed
the paper to the next page is compensated to eliminate the
transfer error created during printing. However, the transfer
control method does not consider the transfer error in a
15 transfer section, but consider the transfer error during
printing. For this reason, after the printing is completed, it
is not possible to eliminate the transfer error which is
! created when the paper is fed to the next page. Further, since
it is not possible to prevent accumulation in the transfer
20 errors, a printing start position shift may be increased at a
next page in a case where the transfer amount is high due to
the many number of pages.
SUMMARY
25 [0007] An aspect of the present disclosure has been made I
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5
in view of the above circumstances, and an advantage of some
aspect of the disclosure is to provide a printer capable of
having a good balance between high precise printing using
transfer precision of a paper feed roller and prevention of
5 accumulation in transfer errors.
[0008] According to an aspect of the disclosure, a
transfer control method of continuous paper in a printer
including a tractor having a sequential engagement portion
which is engaged with engagement holes formed along a
10 longitudinal direction of the continuous paper in which page
dividing positions are set at regular intervals, and a paper
feed roller provided at a downstream side in a transfer
direction of the tractor, the printer transferring the
continuous paper using the paper feed roller and the tractor
^ 15 through a printing position of a printing head, the transfer
control method includes controlling a transfer amount of the
continuous paper based on a rotational amount detected by a
roller feeding amount detecting unit which detects the
rotational amount of the paper feed roller, when each page of
20 the continuous paper is printed, and when the printing on each
page is completed, performing a cueing process of transferring
the continuous paper until a printing start position of a next
page reaches the printing position. The cueing process
includes transferring the continuous paper until the
25 continuous paper reaches a reference transfer position at
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6
which a distance between the printing start position of the
next page and the printing position is equal to a reference
dimension based on the feeding amount of the tractor detected
by a tractor feeding amount detecting unit for detecting a
5 feeding amount of the tractor, and after the continuous paper
reaches the reference transfer position, setting the transfer
amount of the continuous paper with which the printing start
position of the next page reaches the printing position from
the reference transfer position as a target feeding amount.
10 [0009] As described above, an aspect of the disclosure
performs the high precise printing by transferring the
continuous paper with the transfer precision of the paper feed
roller during printing of each page, based on the detected
value from the roller feeding amount detecting unit. Meanwhile,
15 in the cueing process of positioning the printing start
position of the next page at the printing position, the
continuous paper is transferred to the preset reference
transfer position using the detected value from the tractor
feeding amount detecting unit, and at this point, the transfer
20 amount of the continuous paper in the remaining transfer
section is reset as the target feeding amount. The tractor
feeding amount detecting unit can accurately detect a feeding
amount of the engagement portion which moves by physical
engagement with the engagement hole. There may be an error
25 within a play range between the engagement hole and the
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engagement portion, but a transfer error is not accumulated
even though the transfer amount is increased. Accordingly, by
performing such a control in the example, the accurate target
feeding amount can be set at the point for the remaining
5 transfer section when the printing start position of the next
page is sufficiently close to the printing position. Therefore,
since the printing start position shift can be reduced, it is
possible to prevent the accumulation in the transfer error
occurring at each page. In addition, according to the method,
10 it is not necessary to perform a complicated process, such as
a process of calculating a transfer error and compensating the
transfer amount, and it is preferable to detect the reach of
the continuous paper to the preset reference transfer position
using the tractor feeding amount detecting unit, and to set
15 the target transfer amount from that point as the determined
value. Accordingly, the control is easy.
[0010] In an aspect of the disclosure, the transfer of
the set target feeding amount is controlled based on a
detected value from the tractor feeding amount detecting unit.
20 In this way, the transfer error caused by the slip of the
paper feed roller in the remaining transfer section is not
added.
[0011] Alternatively, in an aspect of the disclosure, the
transfer of the set target feeding amount may be controlled
25 based on a detected value from the roller feeding amount
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detecting unit. In this way, it is possible to perforin the
transfer in the remaining transfer section with the feed
precision of the paper feed roller. Further, in this instance,
it is preferable that after the transfer of the continuous
5 paper in the remaining transfer section is performed based on
the set target feeding amount, the actual feeding amount of
the continuous paper in the remaining transfer section is
calculated based on the detected value from the tractor
feeding amount detecting unit, and a difference between the
10 actual feeding amount and the target feeding amount is
calculated, and in a next cueing process, the target feeding
amount is compensated to eliminate the difference. In this way,
since a slight transfer error occurring in the remaining
transfer section can be figured out, and then be eliminated at
15 the next page, it is possible to reduce the transfer error in
the remaining transfer section, and to prevent the
accumulation thereof.
[0012] In an aspect of the disclosure, the reference
transfer position is a position in which a preset reference
20 engagement hole provided at a downstream side in a transfer
direction rather than the printing start position of the next
page reaches the printing position, and the distance between
the reference engagement hole and the printing start position
of the next page is set as the target feeding amount. For the
25 continuous paper with the engagement holes formed along the
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longitudinal direction and page divisions, such as cut holes,
provided at regular intervals, the cut holes (page division)
and the engagement holes have a constant position relation in
the product. The distance from each engagement hole to the
5 printing start position of the next page is accuratelydetermined
in advance. Accordingly, when the preset reference
engagement hole (e.g., engagement hole just before the cut
hole, or engagement hole located at a downstream side by the
predetermined number from the cut hole) passes through the
10 printing position, this is detected on the basis of the
detected value of the tractor feeding amount detecting unit,
and then the distance between the reference engagement hole
previously stored and the printing start position of the next
page is set as the target feeding amount. Therefore, the
15 continuous paper can be transferred with high precision by the
simple control.
[0013] According to another aspect of the disclosure, a
printer includes a printing head, a tractor that has a
sequential engagement portion which is engaged with engagement
20 holes formed along a longitudinal direction of continuous
paper, of which page dividing positions are set at regular
intervals, the tractor transferring the continuous paper along
a transfer path which passes through a printing position of
the printing head, a tractor feeding amount detecting unit
25 that detects a feeding amount of the tractor, a paper feed
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roller that is provided at a downstream side in a transfer
direction of the tractor, a roller feeding amount detecting
unit that detects a rotational amount of the paper feed roller,
a printing control unit that performs printing on each page of
5 the continuous paper transferred by a transferring force of
the paper feed roller using the printing head, and a cueing
control unit that transfers the continuous paper until a
printing start position of a next page reaches the printing
position, when printing of each page is completed. The cueing
10 control unit transfers the continuous paper until the
continuous paper reaches a reference transfer position at
which a distance between the printing start position of the
next page and the printing position is equal to a reference
dimension based on a detected value from the tractor feeding
15 amount detecting unit. After the continuous paper reaches the
reference transfer position, sets the transfer amount of the
continuous paper with which the printing start position of the
next page reaches the printing position from the reference
transfer position as a target feeding amount.
20 [0014] As described above, an aspect of the disclosure
performs the high precise printing by transferring the
continuous paper with the transfer precision of the paper feed
roller during printing of each page, based on the detected
value from the roller feeding amount detecting unit. Meanwhile,
25 in the cueing process of positioning the printing start
11
position of the next page at the printing position, the
continuous paper is transferred to the preset reference
transfer position using the detected value from the tractor
feeding amount detecting unit, and at this point, the target
5 feeding amount in the remaining transfer section is reset.
Therefore, the target feeding amount in the remaining transfer
section can be accurately set when the printing start position
of the next page is sufficiently close to the printing
position. Therefore, since the printing start position shift
10 can be reduced, it is possible to prevent the accumulation in
the transfer error occurring at each page. In addition, it is
preferable to detect the reach of the continuous paper to the
preset reference transfer position using the tractor feeding
amount detecting unit, and to set the target transfer amount
15 from that point as the determined value. Accordingly, the
control is easy.
[0015] In an aspect of the disclosure, the cueing control
unit controls the transfer amount of the continuous paper in
the remaining transfer section, based on the detected value
20 from the tractor feeding amount detecting unit. In this way,
the transfer error caused by the slip of the paper feed roller
in the remaining transfer section is not added.
[0016] Alternatively, in an aspect of the disclosure, the
cueing control unit may control the transfer of the set target
25 feeding amount based on a detected value from the roller
12
feeding amount detecting unit. In this way, it is possible to
perform the transfer in the remaining transfer section with
the feed precision of the paper feed roller. Further, in this
instance, it is preferable that after the transfer of the
5 continuous paper in the remaining transfer section is
performed based on the set target feeding amount, the cueing
control unit calculates an actual feeding amount of the
continuous paper in the remaining transfer section based on
the detected value from the tractor feeding amount detecting
10 unit, and calculates a difference between the actual feeding
amount and the target feeding amount, and in a next cueing
process, the target feeding amount is compensated to eliminate
the difference. In this way, since a slight transfer error
occurring in the remaining transfer section can be figured out,
15 and then be eliminated at the next page, it is possible to
reduce the transfer error in the remaining transfer section,
and to prevent the accumulation thereof.
[0017] In an aspect of the disclosure, the reference
transfer position is a position in which a preset reference
20 engagement hole provided at a downstream side in a transfer
direction rather than the printing start position of the next
page reaches the printing position, and the cueing control
unit sets the distance between the reference engagement hole
and the printing start position of the next page as the target
25 feeding amount. In this way, using the fact that the cut holes
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(page division) and the engagement holes have a constant
position relation in the product, a transfer position of a
specific engagement hole may be figured out based on the
detected value of the tractor feeding amount detecting unit,
5 and then the distance between the engagement hole previously
stored and the printing start position of the next page is set
as the target feeding amount. Therefore, the continuous paper
can be transferred with high precision by the simple control.
[0018] According to an aspect of the disclosure, the
10 continuous paper is transferred with the transfer precision of
the paper feed roller on the basis of the detected value from
the roller feeding amount detecting unit, thereby performing
the high precise printing. Also, after the printing is
completed, the control of the feeding amount and the set of
15 the target feeding amount are performed by use of the detected
value from the tractor feeding amount detecting unit.
Therefore, it is possible to prevent accumulation in the
transfer errors which are created from each page, and to
decrease the printing start position shift.
20
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Fig. lA is a perspective view of a printer.
Fig. IB is a longitudinal cross-sectional view
schematically illustrating major parts of the printer.
25 Fig. 2 is an explanatory view of continuous paper.
14
Fig. 3 is a block diagram schematically illustrating a
control system of the printer.
Fig. 4 is a flowchart illustrating a printing operation
of the continuous paper.
5 Fig. 5 is a flowchart illustrating a printing operation
of a continuous paper according to a modification.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0020] Now, an embodiment of a printer and a transfer
10 control method of continuous paper according to an aspect of
the disclosure will be described with reference to the
accompanying drawings.
Overall Configuration
[0021] Fig. lA is a perspective view of a printer, and Fig.
15 IB is a longitudinal cross-sectional view schematically
illustrating major parts of the printer. A printer 1 is
configured to print continuous paper 2 (recording medium) with
sprocket holes (engagement holes) 2a formed at both end
portions thereof along a paper width direction. The printer 1
20 includes a printer body 3 and a tractor 4 detachably mounted
to a rear portion of the printer body 3 in a front-rear
direction of the printer. The continuous paper 2 is conveyed
from a rear side of the printer into the printer body 3 by the
tractor 4, and then is discharged to a front side of the
25 printer from the printer body 3 after printing is performed.
15
[0022] In the printer body 3, a transfer path P is set in
a straight type in the front-rear direction of the printer, via
a printing position A, in which the continuous paper 2 is
printed by a printing head 5, and a paper transfer passage 6
5 for transferring the continuous paper 2 along the transfer
path P is formed. The printing position A is defined by a
platen 7 which is disposed below the paper transfer passage 6,
and the printing head 5 is disposed at a position opposite to
the platen 7.
10 [0023] A paper feed roller 8 is disposed between the
printing position A and the tractor 4 to feed the continuous
paper 2 to the printing position A. A paper feed/press roller
9 is disposed above the paper feed roller 8. The paper
feed/press roller 9 is biased in a downward direction by a
15 pressing unit (not illustrated), and thus abuts against the
paper feed roller 8 from an upper side by a desired biasing
force. Further, a paper discharge roller 12 for discharging
the printed continuous paper 2 is disposed at the front side
of the printer (downstream in a paper feed direction) rather
20 than the printing position A. A paper press roller 13 is
disposed above the paper discharge roller 12. The paper
feed/press roller 13 is biased in the downward direction by a
pressing unit (not illustrated) , and abuts against the paper
discharge roller 12 from the upper side by a desired pressing
25 force.
16
[0024] A driving force is transmitted to the paper feed
roller 8 from a paper feed motor 10 via a first driving force
transmitting mechanism llA consisting of a gear train, as
denoted by a dotted line in Fig. lOB. The paper feed motor 10
5 is mounted on the printer body 3. Further, the driving force
transmitted to the paper feed roller 8 from the paper feed
motor 10 is transmitted to the paper discharge roller 12 via a
second driving force transmitting mechanism IIB consisting of
a gear train. A roller encoder 14 (roller feeding amount
10 detecting unit) for detecting a rotational amount of the paper
feed roller 8 is mounted on a rotation shaft of the paper feed
roller 8. In this instance, the roller encoder 14 may be
attached to a rotation shaft which rotates in unison with one
of gears constructing the first driving force transmitting
15 mechanism llA.
[0025] Between the paper feed roller 8 and the tractor 4,
a paper detector 15 is provided at a position, at the rear
side of the printer (upstream in the paper feed direction),
adjacent to the paper feed roller 8. The paper detector 15 is,
20 for example, a reflection type photosensor, and detects the
continuous paper 2 which is transferred to the paper transfer
passage 6 by the tractor 4.
[0026] The tractor 4 includes tractor pins (engagement
portions) 16 which can be inserted into the sprocket holes 2a
25 of the continuous paper 2, a tractor belt 17 with the tractor
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pins 16 formed on its outer circumference at regular intervals,
and a drive sprocket 18 and a driven sprocket 19 with the
tractor belt 17 mounted therebetween. The drive sprocket 18 is
provided with a tractor encoder 20 (tractor feeding amount
5 detecting unit) for detecting a rotational amount of the drive
sprocket 18. In this instance, the tractor encoder 20 may be
mounted on the driven sprocket 19.
[0027] The tractor 4 is provided with a tractor drive
motor 21. A driving force is transmitted to the drive sprocket
10 18 from the tractor drive motor 21 via a third driving force
transmitting mechanism 22. The third driving force
transmitting mechanism 22 includes a clutch mechanism 23, and
the clutch mechanism 23 is configured to interrupt or connect
the transmission path of the driving force between the tractor
15 drive motor 21 and the tractor 4.
[0028] When the continuous paper 2 is transferred by the
tractor 4, the continuous paper 2 is set so that the tractor
pins 16 are inserted into the sprocket holes 2a. After that,
the drive sprocket 18 is rotated by the driving force of the
20 tractor drive motor 21 to rotate the tractor belt 17.
Accordingly, the tractor pins 16 are sequentially engaged with
the sprocket holes 2a to continuously transfer the continuous
paper 2.
[0029] The printing head 5 is an Inkjet head, and is
25 mounted on a carriage 24 which is disposed above the paper
18
transfer passage 6. The carriage 24 holds the printing head 5
at a position between the plate 7 and the printing head 5. The
carriage 24 is able to reciprocate in a scanning direction
perpendicular to the paper feed direction by the driving force
5 of the carriage motor 25.
[0030] The carriage 24 is provided with a paper width
detector 26. The paper width detector 26 is, for example, a
reflection type photosensor which is installed at a portion of
the carriage 24 facing the platen 7. The paper width detector
10 2 6 irradiates an inspection light toward the platen 7, and
then detects a reflected light from the platen 7 or the
continuous paper 2 transferred on the platen 7. It is possible
to detect a left end and a right end of the continuous paper 2
by the paper width detector 26 which is operated in
15 conjunction with the movement of the carriage 24 in a
direction perpendicular to the paper feed direction. On the
basis of the detected result, the paper width of the
continuous paper 2 can be detected, and simultaneously, a
passing position of the continuous paper 2 in the direction
20 perpendicular to the paper feed direction (transfer direction)
can be detected.
Continuous Paper
[0031] Fig. 2 is an explanatory view of the continuous
paper 2. Page break positions are set on the continuous paper
25 2 at regular intervals in the longitudinal direction thereof.
19
and cut holes 2b are formed at each page break position. The
continuous paper 2 is bent to alternatively form ridge folds
and valley folds in its longitudinal direction at the position
of the cut holes 2b, and is folded in a shape of a booklet-
5 like bunch. As the end portion of the continuous paper 2 drawn
from the uppermost surface of the bunch is loaded on the
printer 1, and then the continuous paper 2 is sequentially
drawn from the folded uppermost layer, the continuous paper 2
is fed to the printer 1. A stylized printed matter can be
10 issued by performing the printing on each page of the
continuous paper 2 which is divided by the cut holes 2b and
then cutting the continuous paper 2 at the cut holes 2b after
printing. A margin of a constant length is provided between a
printing start position 2c and the cut holes 2b of each page.
15 [0032] The sprocket holes 2a are arranged at regular
pitches in its longitudinal direction at both end portions of
the continuous paper 2 in the paper width direction. The
sprocket holes 2a of each page are disposed in a constant
position relation with the cut holes 2b which are disposed at
20 the leading and trailing ends of each page. In this embodiment,
the sprocket hole 2a disposed at the second position when
counting it from the cut hole 2b of the trailing end of each
page to the leading end of the page (i.e., downstream side in
the transfer direction) is regarded as a reference sprocket
25 hole 2c (reference engagement hole) in a cueing process which
20
will be described later. A distance LI from the reference
sprocket hole 2d to the printing start position 2c of the next
page, and a distance L2 from the reference sprocket hole 2d
and the printing start position 2c of the same page are the
5 same dimension for all page.
Control System
[0033] Fig. 3 is a block diagram schematically
illustrating the control system of the printer 1. The control
system of the printer 1 is mainly configured of a control unit
10 30 having a CPU, a ROM, and a RAM. The control unit 30 is
input by a printing command from an external appliance (not
illustrated) , or the detected values from the paper detector
15, the paper width detector 26, the roller encoder 14, and
the tractor encoder 20. The printing head 5 is connected to
15 the output side of the control unit 30 via the head driver 31.
Further, the control unit 30 is connected to the paper feed
motor 10 via a first motor driver 32, is connected to the
tractor drive motor 21 via a second motor driver 33, and is
connected to the carriage motor 25 via a third motor driver 34.
20 [0034] The control unit 30 includes a tractor drive
control portion 35, a printing control portion 36, and a
cueing control portion 37. If the control unit 30 receives the
printing command, the tractor drive control portion 35
controls the driving of the tractor drive motor 21 to drive
25 the tractor 4 and thereby to transfer the set continuous paper
21
2 to the tractor 4. Further, if the leading end of the
continuous paper 2 is detected by the paper detector 15, the
tractor drive control portion 35 transfers the continuous
paper 2 by a predetermined feeding amount by use of the
5 tractor 4, so that the leading end of the continuous paper 2
is inserted into a nip portion between the paper feed roller 8
and the paper feed/press roller 9. Subsequently, the driving
of the tractor 4 is stopped, and simultaneously, the clutch
mechanism 23 is controlled to interrupt the transmission path
10 of the driving force between the tractor drive motor 21 and
the tractor 4. If the transmission path is interrupted, the
tractor 4 is driven by following the transfer of the
continuous paper 2 which is caused by the paper feed roller 8.
[0035] Based on the detection of the leading end of the
15 continuous paper 2 by the paper detector 15, the printing
control system 36 drives the paper feed motor 10 to start
rotation of the paper feed roller 8, and thus the delivery of
the continuous paper 2 from the tractor 4 is executed. Further,
if the transfer of the tractor 4 is stopped, the continuous
20 paper 2 is transferred by the paper feed roller, and then the
printing start position 2c of the initial page is determined
at the printing position A. Subsequently, in conjunction with
the transfer operation of the continuous paper 2 by the
transfer force of the paper feed roller 8, the driving of the
25 carriage motor 25 and the discharge of the ink by the printing
22
head 5 are controlled to perforin the printing of the
continuous paper 2. The printing control portion 36 controls
the transfer amount of the continuous paper 2 based on the
detected value from the roller encoder 14.
5 [0036] If the printing corresponding to one page by the
printing control portion 36 is completed, the cueing control
portion 37 continuously transfers the continuous paper 2 using
the paper feed roller to feed the continuous paper 2 to the
next page, and performs the cueing to transfer the continuous
10 paper 2 until the printing start position 2c of the next page
is determined at the printing position A. If the cueing starts,
the cueing control portion 37 first monitors the transfer
position of the continuous paper 2 based on the detected value
from the tractor encoder 20, and then transfers the continuous
15 paper 2 until the reference sprocket hole 2d disposed at the
second position when counting from the trailing end of the
page toward the leading end of the page reaches the printing
position A. Further, the cueing control portion 37 sets the
target feeding amount for the remaining transfer section until
20 the printing start position 2c of the next page reaches the
printing position A. After that, the continuous paper 2 is
transferred according to the set target feeding amount.
[0037] As described above, the distance from the reference
sprocket hole 2d to the printing start position 2c of the next
25 page is LI for every page. In this embodiment, the distance LI
' .,
23
(reference dimension) is stored in the cueing control portion
37. The cueing control portion 37 transfers the continuous
paper 2 until the reference sprocket hole 2d reaches the
printing position A, that is, the continuous page 2 reaches
5 the reference transfer position in which the distance LI
between the printing position A and the printing start
position 2c of the next page is LI. The value of Ll in the
second process is read, and then the target feeding amount is
set as Ll.
10 [0038] The detected value form the tractor encoder 20 is
reflected by the movement amount of the tractor pin 16 engaged
with the sprocket hole 2a. The movement amount of the tractor
pin 16 is reflected by the actual feeding amount of the
continuous paper 2 although there is an error within a play
15 range between the sprocket hole 2a and the tractor pin 16.
Accordingly, it is possible to calculate the actual feeding
amount of the continuous paper 2 based on the detected value
of the tractor encoder 20, irrespective of whether the tractor
4 is the main feeding unit or not. The cueing control portion
20 37 calculates the actual feeding amount from the printing
start time of each page based on the detected value from the
tractor encoder 20, thereby monitoring the transfer position
of the continuous paper 2. When the calculated actual feeding
amount is equal to the above-described distance L2 (the
25 distance from the printing start position 2c of the leading
24
end of the page to the reference sprocket hole 2d of the
trailing end of the same page), the cueing control portion 37
determines that the reference sprocket hole 2d reaches the
printing position A.
5 [0039] The cueing control portion 37 controls the transfer
amount of the continuous paper 2 based on the detected value
from the tractor encoder 20, when the continuous paper 2 is
transferred to the reference transfer position. Further, even
when the continuous paper is transferred by the target feeding
10 amount in the remaining transfer section after it reaches the
reference transfer position, the cueing control portion 37
controls the transfer amount of the continuous paper 2 based
on the detected value from the tractor encoder 20.
[0040] Printing Operation
15 [0041] Fig. 4 is a flowchart illustrating the printing
operation of the continuous paper 2. If the control unit 30 of
the printer 1 receives the printing command from the external
appliance, it starts the process of step SI. In step SI, the
tractor drive control portion 35 transfers the continuous
20 paper 2 using the tractor 4 to deliver it to the paper feed
roller 8. That is, the tractor 4 is driven, and the continuous
paper 2 set in the tractor 4 is fed to the paper transfer
passage 6. After that, if the leading end of the continuous
paper 2 is detected by the paper detector 15, the tractor
25 drive control portion 35 transfers the continuous paper 2 by
25
the predetermined feeding amount using the tractor 4 to insert
the leading end of the continuous paper 2 into the nip portion
! between the paper feed roller 8 and the paper feed/press
roller 9. And, it proceeds to step S2.
5 [0042] In step S2, the tractor drive control portion 35
stops the driving of the tractor 4, and controls the clutch
mechanism 23 to interrupt the transmission path of the driving
force between the tractor drive motor 21 and the tractor 4, so
that the tractor 4 is in the state which can be driven by the
10 transfer of the continuous paper 2 caused by the paper feed
roller 8.
[0043] In step S3, the printing control portion 36 starts
the transfer of the continuous paper 2 by the transfer force
of the paper feed roller 8 to determine the continuous paper 2
15 at the printing position A. Subsequently, the printing control
portion 36 performs the printing corresponding to one page.
That is, in conjunction with the transfer operation of the
continuous paper 2 by the transfer force of the paper feed
roller 8, the printing control portion 36 controls the driving
20 of the carriage motor 25 and the discharge of the ink by the
printing head 5 to perform the printing of the continuous
paper 2. In step S4, the printing control portion 36 controls
the transfer amount of the continuous paper 2 based on the
detected value from the roller encoder 14. If the printing
25 corresponding to one page is completed, it proceeds to step 85.
>
26
[0044] In step S5, the cueing control portion 37 transfers
the continuous paper 2 using the paper feed roller, and
controls the transfer amount of the continuous paper 2 based
on the detected value from the tractor encoder 20.
5 Simultaneously, the cueing control portion 37 performs the
cueing to transfer the continuous paper 2 until the printing
start position 2c of the next page reaches the printing
position A.
[0045] In step S5, whenever the continuous paper 2 is
10 transferred by a unit amount by the paper feed roller (step
S51) , it is determined based on the detected value from the
tractor encoder 20 whether or not the actual feeding amount L2
is achieved, in other words, the continuous paper 2 reaches
the reference transfer position (step S52). If the actual
15 feeding amount L2 is achieved (Yes in step S52), it proceeds
to step S53, and the target feeding amount of the remaining
transfer section is set as LI. Subsequently, it proceeds to
step S54, and while the transfer amount of the continuous
paper 2 is controlled based on the detected value from the
20 tractor encoder 20, the continuous paper 2 is transferred by
the target feeding amount LI. It proceeds to step S6.
[0046] In step S6, the cueing control portion 37
determines whether a printing job is completed or not. That is,
it is determined whether the printing of the finale page is
25 completed or not, and if the printing is completed (Yes in
27
step S6) , the process is completed. Meanwhile, if the printing
job is remained (No in step S6) , it returns to step S4, and
steps S4 and S5 are repeated until the printing job is
completed.
5 [0047] As described above, the printer 1 according to this
embodiment can perform the high precise printing by
transferring the continuous paper 2 with the transfer
precision of the paper feed roller 8 during printing of each
page. Meanwhile, in the cueing process of positioning the
10 printing start position 2c of the next page at the printing
position A after the printing is completed, the continuous
paper 2 is transferred until the printing start position 2c of
the next page is sufficiently close to the printing position A,
specifically, the reference sprocket hole 2d sufficiently
15 close to the printing start position 2c of the next page
reaches the printing position A, based on the detected value
from the tractor encoder 20. At this point, the target feeding
amount in the remaining transfer section is again set as the
accurate value LI. If the feeding amount is controlled using
20 the detected value from the tractor encoder 20, as described
above, a transfer error is not accumulated even though the
feeding amount is increased. Accordingly, the accurate target
feeding amount is set at the point, in which the remaining
transfer amount is small, in the cueing process based on the
25 detected value from the tractor encoder 20. Therefore, even
28
I though a shift is caused by slip during printing, it is
possible to eliminate the shift, and the transfer errors are
not accumulated from the previous pages. In addition, since
the control is performed based on the detected value from the
5 tractor encoder 20 in the final remaining transfer section, it
is possible to prevent the transfer error from occurring in
the remaining transfer section. In this embodiment, since the
control based on the detected value from the roller encoder 14
and the control based on the detected value from the tractor
10 encoder 20 are properly combined, it is possible to have a
good balance between high precise printing and prevention of
accumulated transfer shift with simple control.
Modification
[004 8] Although the transfer control method of the above-
15 described embodiment controls the transfer amount based on the
detected value from the tractor encoder 20 in the remaining
transfer section immediately before the cueing process is
completed, a transfer control method of the modification
performs the control of the feeding amount in the remaining
20 transfer section based on the detected value from the roller
encoder 14, and simultaneously, calculating the feed error in
the remaining transfer section, thereby compensating a target
I
feeding amount to eliminate the error in the next page. I
[0049] Fig. 5 is a flowchart illustrating the printing
25 operation of the continuous paper 2 according to the
•
29
modification. The processes of steps SI to S4 and S6 in the
modification are equal to those of the above embodiment. In
the cueing process (step S5A), the cueing control portion 37
controls the transfer amount of the continuous paper 2 based
5 on the detected value from the roller encoder 14, and performs
the process of transferring the continuous paper 2 by the
target feeding amount LI (step S54A), instead of step S54.
[0050] In this modification, if the printing job is
remained in step S6 (No in step S6) , it returns to step S4 via
10 step S7. In step S7, the actual feeding amount in the
remaining transfer section is calculated based on the detected
value from the tractor encoder 20, and a difference between
the target feeding amount LI which is the set feeding amount
and the actual feeding amount is calculated. The cueing
15 control portion 37 stores the calculated difference therein,
and compensates the target feeding amount to eliminate the
calculated difference in a process (step S53A) of setting the
target feeding amount of the remaining transfer section at the I
time of the next cueing process. For example, if the target
20 feeding amount is LI and the actual feeding amount is less
than LI, the compensation is performed by adding the
difference to the target feeding amount Ll. In this way, if
the transfer error occurs while the continuous paper is
transferred with the transfer precision of the paper feed
25 roller in the remaining transfer section, the transfer error
30
can be eliminated in the next page. Therefore, it is possible
to prevent the accumulation in the transfer error.

s
31
What is claimed is:
1. A transfer control method of continuous paper in a
printer including a tractor having a sequential engagement
portion which is engaged with engagement holes formed along a
5 longitudinal direction of the continuous paper in which page
dividing positions are set at regular intervals, and a paper
feed roller provided at a downstream side in a transfer
direction of the tractor, the printer transferring the
continuous paper using the paper feed roller and the tractor |
10 through a printing position of a printing head, the transfer
control method comprising:
controlling a transfer amount of the continuous paper
based on a rotational amount detected by a roller feeding
amount detecting unit which detects the rotational amount of
15 the paper feed roller, when each page of the continuous paper
is printed; and
when the printing on each page is completed, performing
a cueing process of transferring the continuous paper until a
printing start position of a next page reaches the printing
20 position;
wherein the cueing process includes:
transferring the continuous paper until the
continuous paper reaches a reference transfer position
at which a distance between the printing start position
25 of the next page and the printing position is equal to a
32
reference dimension based on the feeding amount of the
tractor detected by a tractor feeding amount detecting
unit for detecting a feeding amount of the tractor, and
after the continuous paper reaches the reference
5 transfer position, setting the transfer amount of the
continuous paper with which the printing start position
of the next page reaches the printing position from the
reference transfer position as a target feeding amount.
10 2. The transfer control method of the continuous paper
according to claim 1, wherein the transfer of the set target
feeding amount is controlled based on a detected value from
the tractor feeding amount detecting unit.
15 3. The transfer control method of the continuous paper
according to claim 1, wherein the transfer of the set target
feeding amount is controlled based on a detected value from
the roller feeding amount detecting unit.
20 4. The transfer control method of the continuous paper
according to claim 3, wherein after the transfer of the
continuous paper in the remaining transfer section is
performed based on the set target feeding amount, the actual
feeding amount of the continuous paper in the remaining
25 transfer section is calculated based on the detected value
33
from the tractor feeding amount detecting unit, and a
difference between the actual feeding amount and the target
feeding amount is calculated, and
in a next cueing process, the target feeding amount is
5 compensated to eliminate the difference.
5. The transfer control method of the continuous paper
according to claim 1, wherein the reference transfer position
is a position at which a preset reference engagement hole
10 provided at a downstream side in a transfer direction rather
than the printing start position of the next page reaches the
printing position, and
the distance between the reference engagement hole and
the printing start position of the next page is set as the
15 target feeding amount.
6. A printer comprising:
a printing head;
a tractor that has a sequential engagement portion which
20 is engaged with engagement holes formed along a longitudinal
direction of continuous paper, of which page dividing {
positions are set at regular intervals, the tractor
transferring the continuous paper along a transfer path which
passes through a printing position of the printing head;
25 a tractor feeding amount detecting unit that detects a
«
34
feeding amount of the tractor;
a paper feed roller that is provided at a downstream
side in a transfer direction of the tractor;
a roller feeding amount detecting unit that detects a
5 rotational amount of the paper feed roller;
a printing control unit that performs printing on each
page of the continuous paper transferred by a transferring
force of the paper feed roller using the printing head; and
a cueing control unit that transfers the continuous
10 paper until a printing start position of a next page reaches
the printing position, when printing of each page is completed,
wherein the cueing control unit transfers the continuous
paper until the continuous paper reaches a reference transfer
position at which a distance between the printing start
15 position of the next page and the printing position is equal
to a reference dimension based on a detected value from the
tractor feeding amount detecting unit, and
after the continuous paper reaches the reference
transfer position, sets the transfer amount of the continuous
20 paper with which the printing start position of the next page
reaches the printing position from the reference transfer
position as a target feeding amount.
7. The printer according to claim 6, wherein the cueing
25 control unit controls the transfer of the set target feeding
35
amount based on the detected value from the tractor feeding
amount detecting unit.
8. The printer according to claim 6, wherein the cueing
5 control unit controls the transfer of the set target feeding
amount based on a detected value from the roller feeding
amount detecting unit.
9. The printer according to claim 8, wherein after the
10 transfer of the continuous paper in the remaining transfer
section is performed based on the set target feeding amount,
the cueing control unit calculates an actual feeding amount of
the continuous paper in the remaining transfer section based ;
on the detected value from the tractor feeding amount
15 detecting unit, and calculates a difference between the actual
feeding amount and the target feeding amount, and
in a next cueing process, the target feeding amount is
compensated to eliminate the difference.
20 10. The printer according to claim 6, wherein the reference
transfer position is a position in which a preset reference
engagement hole provided at a downstream side in a transfer
direction rather than the printing start position of the next
page reaches the printing position, and
25 the cueing control unit sets the distance between the
*
36
reference engagement hole and the printing start position of
the next page as the target feeding amount.