JP6381323B2 - Recording device - Google Patents

Description

  The present invention relates to a recording apparatus having a winding function, and more particularly to a recording apparatus that reduces the influence of a winding force on the conveyance accuracy of the recording apparatus.

  Conventionally, in an image recording apparatus such as a printer or a plotter that handles a roll-shaped recording medium, the quality of the recording medium can be maintained and productivity can be avoided, for example, by avoiding bending of the recorded recording medium or fouling of the image. There are known means for increasing the value. As this means, a winding device for winding the discharged recording medium is used.

  As a general winding method, there is a direct winding method. This direct winding method is a method in which a winding motor winds at a constant winding torque via a mechanism (for example, a torque limiter) capable of controlling torque on a winding shaft (see, for example, Patent Document 1). ). This conventional example has a feature that it is inexpensive because it has a simple structure, and it is difficult to generate wrinkles because the sheet is wound while tension is applied.

JP 61-172768 A

  In the direct winding type of Patent Document 1, a torque limiter for controlling the winding force is inserted between the winding motor and the winding shaft, and the winding is wound with a predetermined winding force. For this reason, when the roll paper is transported, a tensile force is applied in the transport direction, and the roll paper tends to be fed more than the original transport amount. If printing is performed in this overfeed state, there is a problem that a gap is formed at the joint of the images and the image quality may be deteriorated. Further, depending on the winding timing, there is a problem that the ink landing accuracy is lowered.

  An object of the present invention is to provide a recording apparatus in which image quality does not deteriorate.

  In order to achieve the above object, the present invention provides a conveyance roller for conveying roll paper, a recording head for recording on roll paper conveyed by the conveyance roller, and a direction in which a sheet is conveyed by mounting the recording head A carrier that moves in a direction intersecting with the recording head, a take-up spool that winds up the roll paper that has been recorded by the recording head, a transport operation that transports the roll paper by a predetermined amount by the transport roller, and the transport roller stops. And a recording operation in which the carrier is moved in the intersecting direction and recording is performed on the roll paper by the recording head, and the transport operation is performed by the transport roller when the transport operation is performed. By not driving the take-up spool, the roll paper is loosened between the transport roller and the take-up spool. Control means for performing a winding operation for winding the roll paper by driving the take-up spool, the control means based on the outer diameter of the roll paper wound on the take-up spool. The timing for starting the winding operation is determined.

  According to the present invention, when the winding is performed by the direct winding method, the winding timing is set in conjunction with the roll paper transport operation, so that the ink is landed at a desired position, and no gap is formed at the joint of the image. There is an effect that it is possible to obtain a clean printed image in which the image quality does not deteriorate.

1 is a schematic cross-sectional view of an inkjet printer 1 that is an example of a printing apparatus. It is a perspective view which shows the structure of the roll paper attachment part of a paper feed part. 3 is a schematic diagram of a drive system for an LF roller 9, a drive system for a spool shaft 32, and the like. FIG. 2 is a block diagram of a control system related to the inkjet printer 1. FIG. FIG. 10 is an explanatory diagram of the effect of the slack / tension operation of the roll paper R. It is a figure which shows the slack state of the roll paper at the time of conveyance and winding after printing. 4 is a timing chart showing the movement of each element and the state of the roll paper R. FIG. It is a timing diagram which shows each element and the state of roll paper. It is a flowchart which shows the relationship of each operation | movement of conveyance, printing, and winding. It is a timing diagram which shows each element and the state of roll paper. It is a flowchart which shows the relationship of each operation | movement of conveyance, printing, and winding. It is a figure which shows the slack state of the roll paper R at the time of printing and winding up. 4 is a timing chart showing the movement of each element and the state of the roll paper R. FIG. FIG. 10 is a timing diagram of the third embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or corresponding part through each drawing.

  FIG. 1 is a schematic cross-sectional view of an ink jet printer 1 which is an example of a printing apparatus including a winding unit according to the first embodiment of the present invention.

  The inkjet printer 1 uses roll paper R, which is continuous paper wound in a roll.

  FIG. 2 is a perspective view illustrating a configuration of a roll paper attachment unit of the paper supply unit in the inkjet printer 1.

  In the spool on the paper supply side, the spool shaft 32 is passed through the paper tube S provided at the center of the roll paper R. The spool shaft 32 is a conveyance shaft that conveys roll paper. The reference side loading unit 31 of the reference side roll paper holder 30 disposed on the spool shaft 32 bites into the inner wall of the paper tube S by the elastic force in the radial direction. Accordingly, the paper tube S is fixedly held on the spool shaft 32, and the roll paper R is fixed to the spool shaft 32 without rotating. Further, the non-reference side roll paper holder 34 is passed through the spool shaft 32 and set on the paper tube S from the opposite side of the reference side roll paper holder 30 so as to sandwich the roll paper R. A spool gear 33 for receiving a rotational driving force from the inkjet printer 1 is attached to the non-reference side of the spool shaft 32.

  As the spool on the take-up side, basically, a spool having the same shape as the spool shaft 32 on the paper feed side is adopted. That is, only the paper tube S without the roll paper R is set on the spool shaft on the take-up side, and this point is different from the paper feed side.

  In FIG. 1, both ends of the roll paper R are rotatably supported by the inkjet printer 1 via a spool shaft 32. The leading end of the roll paper R fed out from the roll paper R passes through the roll paper detection sensor 41 and is sandwiched between the LF roller 9 and a pinch roller 10 that pressurizes the LF roller 9 with a spring (not shown). In this state, it is conveyed onto the platen 19.

  When the roll paper R is loaded, if the roll paper detection sensor 41 detects the leading edge of the roll paper R, the LF roller 9 is rotated in the transport direction, and the leading edge of the roll paper R is automatically placed between the LF roller pair 9 and 10. Pull in. The member 12 is located immediately above the platen 19, and cooperates with the carrier 12 that scans in the direction orthogonal to the roll paper conveyance direction, the LF roller pairs 9 and 10, and the recording head 11 mounted on the carrier 12. The desired recording is executed on the roll paper R.

  More specifically, both ends of the carrier 12 are fixed to the frame of the ink jet printer 1, and the carrier 12 is slidably supported along a guide shaft 16 and a guide rail (not shown) arranged in parallel to each other. Yes. Then, an image is recorded on the roll paper R by ejecting ink from the recording head 11 while reciprocating the carrier 12 toward the roll paper R conveyed to the image recording unit 2. When an image is recorded by scanning one line by forward or backward movement of the carrier 12 in the image recording unit 2, the roll paper R is fed by a predetermined pitch in the transport direction by the pair of LF rollers 9, 10, and the carrier 12 is moved again. The next line image is recorded. By repeating these operations, an image is recorded on the entire page.

  A paper edge detection sensor 43 using a reflective optical sensor is mounted on the carrier 12 along with the recording head 11. Then, in cooperation with the scanning operation of the carrier 12, the leading end position of the roll paper R in the roll paper transport direction, the reference side end position of the roll paper R in the roll paper width direction, and the roll paper width are detected.

  When cutting the recorded printed matter one by one, the recorded roll paper R is conveyed onto the paper discharge guide 22. When the image recording is completed, the image end portion of the roll paper R is conveyed to the cutting position of the cutter 21 by the LF roller pair 9 and 10 and cut. The recorded printed matter may be continuously recorded without being cut one page at a time, and may be sequentially wound in a roll shape by the winding unit 71 disposed on the downstream side of the paper discharge guide 22. Good.

  When winding the printed matter, it is necessary to wind up the tip of the roll paper R in advance and fix it to the paper tube S of the spool with tape or the like. In this way, the printed matter is sent downstream by the LF roller pair 9 and 10, and if the winding operation is executed at a predetermined timing, the roll paper R is wound up with an appropriate tension. be able to.

  FIG. 3 is a plan view showing the drive system of the LF roller 9, the drive system of the spool shaft 32, and the drive system of the take-up spool shaft.

  The driving force of the LF motor 8 is transmitted to the LF roller 9 through the LF transmission gears 55 and 56. A circular LF encoder film 54 provided with slits radially is attached to the LF roller 9, and the LF encoder sensor 5 monitors the rotation speed and the rotation amount of the LF roller 9 to control the LF roller 9.

  In the spool shaft drive system on the paper feed side, the rotational force of the roll motor 40 is transmitted to the spool gear 33 of the roll shaft via the roll transmission gear 36, the gear 37 and the gear 38. Between the gear 37 and the gear 38, a torque limiter 39 for restricting the transmission torque is provided. When the LF roller 9 transports the roll paper R in the transport direction by locking the rotation of the roll motor 40, A back tension is applied to the roll paper R. Further, when the LF motor 8 and the roll motor 40 are rotated in the direction opposite to the conveying direction, the roll is rewound while applying a back tension by setting the winding speed faster than the speed of the LF roller 9. You can also.

  In the drive system of the spool shaft 32 on the take-up side, the take-up motor 72 applies a rotational force to the spool gear 33 via the roll transmission gear 36, the gear 37, and the gear 38 having the same shape used on the paper feed side. introduce. Between the gear 37 and the gear 38, a torque limiter 39 that restricts the transmission torque is provided. Then, by rotating the winding motor 72 with the LF roller 9 nipping the printed matter, the LF roller 9 slips by the torque limiter 39 and takes up the printed matter while applying a predetermined tension. A circular take-up encoder film 74 provided with slits radially is attached to the spool shaft, and the take-up encoder sensor 73 can be used to monitor and control the rotation speed and the rotation amount of the take-up spool.

  FIG. 4 is a block diagram of a control system related to the ink jet printer 1.

  The control unit 101 of the inkjet printer 1 is connected to the host computer 100 via an interface (not shown). Image data and data related to printing are transferred from the host computer 100 to the control unit 101. The control unit 101 executes processing such as color processing, reduction / enlargement processing, binarization, and the like on the image data transferred from the interface, and finally print data developed in a dot pattern is stored in the control unit 101. Accumulate in memory. The control unit 101 also receives signals from the sensor system LF encoder sensor 5, the take-up encoder sensor 73, the roll paper detection sensor 41, and the paper edge detection sensor 43. And the control part 101 drives the LF motor 8, the roll motor 40, the carrier motor 61 which moves the carrier 12, the cutter 21, and the winding motor 72 as needed.

  The basic winding operation is that after printing an image on the roll paper R, one line is conveyed, a certain amount of slack is generated on the roll paper R, and then the roll paper R is wound on a predetermined condition, whereby tension is applied to the roll paper R. It is an operation to stretch. By repeating the transport operation and the winding operation after printing, a high-quality roll without winding deviation or wrinkle can be produced.

  Next, an effect obtained by winding the roll paper R after causing a certain amount of slack in the roll paper R will be described.

  FIG. 5 is a diagram for explaining the effect of the slack / tension operation of the roll paper R. FIG.

  When the alignment between the LF conveying roller and the winding shaft is shifted as shown in FIG. 5A, if the winding is continuously performed with a constant winding torque, the winding shift grows in the lateral direction of the winding shaft. Winding is performed (so-called lateral displacement winding occurs). When this lateral displacement winding proceeds, the roll paper R continues to be pressed against the flange disposed at the end of the take-up shaft, and the end of the roll paper R is wound while being crushed.

  On the other hand, after the roll paper R has been wound, if the operation of generating a certain amount of slack is performed, the winding force for a part of the wound outer periphery is loosened, and the roll weight is reduced by the weight of the slack recording medium. The paper R returns to the arrow direction shown in FIG. If it winds in this state, a big horizontal shift can be suppressed. By repeating the slack operation and the tension operation, it is possible to regulate the lateral displacement even if the alignment is slightly shifted. That is, when winding while generating a certain slack, the winding operation can be continued while suppressing lateral shift winding, and as a result, there is an effect that the winding can be performed in a high-production and high-quality state. .

  Next, the operation of the above embodiment will be described in more detail.

  In the above configuration, when the roll paper R is taken up by the take-up unit, after one line of image is recorded by the forward or backward movement of the carrier 12, the roll paper R is conveyed by the LF roller pairs 9, 10. Send a certain pitch in the direction. As a result, the roll paper R is loosened by the amount conveyed. Thereafter, when the roll paper is taken up by the take-up unit, the roll paper R is not loosened, and a predetermined tension acts on the roll paper R.

  If winding is performed without considering synchronization with LF conveyance, the timing at which the tension is applied is 2 when the roll paper R is conveyed by the LF roller pair 9 and 10 and when it is not being conveyed. There are two cases. When tension is applied to the roll paper R during conveyance, the grip force of the roll paper R between the LF roller pair 9 and 10 is weak and tends to be fed excessively with respect to a predetermined conveyance amount. The actual transport amount is larger than the predetermined transport amount. When the printing operation is executed in this state, the ink landing position is shifted, and there is a gap with the previous one-line recording, resulting in white stripes. On the other hand, if tension is applied when the roll paper R is not transported, the grip force of the roll paper R between the LF roller pairs 9 and 10 is strong, so there is no slip, and the actual transport amount is the same as the set transport amount. become. When printing is performed in this state, there is no gap between the previous one-line recording and the images are connected neatly.

  Therefore, if the operation of tensioning the roll paper R is performed while the roll paper R is not being conveyed (conveyance stopped) by the LF roller 9 in conjunction with the LF conveyance, the roll paper R is unlikely to slip, and subsequent printing is performed. In operation, the ink lands on the assumed position. This control is particularly effective for slippery media such as glossy paper.

  Further, instead of winding up for each line of printing and a predetermined pitch of conveyance as described above, image recording for one line and conveyance of a predetermined pitch were repeated n times (n is an integer of 2 or more). Later, the slack of the predetermined pitch × n times may be wound together. However, in order to connect the images between the lines neatly, it is necessary to set the timing at which the tension is applied during non-conveyance.

  Next, a schematic operation of the winding operation will be described.

  FIG. 6 is a cross-sectional view showing a loose or stretched state of the roll paper R when the roll paper R is conveyed and wound after printing.

  FIG. 7 is a timing chart showing the state of the roll paper R that changes in response to the movement of each element in the inkjet printer 1.

  First, when the LF roller 9 is conveyed after printing from the state without slack (FIGS. 6A and 7A) (FIGS. 6B and 7B), the roll paper R gradually loosens. The amount increases and the LF roller 9 stops, and at the same time, the increase in the slack amount stops. Thereafter, the carrier motor 61 shown in FIG. 4 is operated to eject ink from the recording head 11 while reciprocating the carrier 12 to print an image on the roll paper R. During the non-conveyance of the roll paper R (conveyance stop) including the operation of the carrier motor 61, the winding motor is operated to remove the slack of the roll paper R (FIGS. 6C and 7C). ). When the looseness of the roll paper R disappears, the tension acts on the roll paper R (FIGS. 6D and 7D). Here, winding is started during non-conveyance, and tension is set to act during non-conveyance. Since tension is applied during non-conveyance (conveyance stop) where the grip force by the LF roller pairs 9 and 10 is strong, the roll paper R does not slip and the conveyance accuracy can be ensured. The winding start is set after a predetermined time has elapsed since the LF motor 8 is stopped. However, the winding may be started simultaneously with the stop of the LF motor 8. That is, in the inkjet printer 1, the tension generation operation performed by the tension generation unit is linked to the conveyance operation by the conveyance unit.

  FIG. 8 is a timing chart showing each element and the state of the roll paper.

  As shown in FIG. 8, the time Tb from the start of winding to the stop of conveyance may be set during the conveyance operation within a range where no tension is applied to the roll paper R during the conveyance operation. By accelerating the winding start timing as much as possible, the completion of winding is accelerated, the non-conveying range can be reduced, and printing with a narrow printing width can be accommodated. A broken line shown in FIG. 8 indicates a change in the amount of looseness of the roll paper R in FIG. 7, and the slack removal can be completed early by advancing the winding start timing.

  Here, an example of calculating the time Tb from the start of winding to the stop of conveyance will be shown.

The time Tb from the start of winding to the conveyance stop can be calculated from the winding speed Vb and the maximum outer diameter Db that can be wound. The interrelationship of time Tb (sec) from winding start to conveyance stop, winding speed Vb (rps), winding maximum outer diameter Db (mm), winding amount Mb (mm) is
Tb * Vb * Db * π = Mb
It is.

If the amount of slack generated in the conveyance of the roll paper R is δ and the amount of slack δ = Mb, the time Tb from the start of winding to the stop of conveyance is
Tb = δ / (Vb * Db * π)
It is.

  When the winding outer diameter is small, the point at which the tension starts to act on the roll paper R is to the right in the middle of the non-conveyance (conveyance stop), but as the winding outer diameter gradually increases, the tension is increased. The acting start point moves to the left. That is, when the winding outer diameter is small, the winding amount per unit time is small, so that the winding time is long in order to eliminate slack. For this reason, when the winding outer diameter is small, the point in time when the tension starts to be applied to the roll paper R is closer to the right in the middle of non-conveyance (conveyance stop). On the other hand, when the winding outer diameter is large, the winding time is shortened in order to eliminate slack. Since the winding amount per unit time is large, the winding time is shortened to eliminate slack. For this reason, when the winding outer diameter is large, the point in time when the tension starts to be applied to the roll paper R is closer to the left in the middle of non-conveyance (conveyance stop).

  When the take-up outer diameter reaches the maximum, a tension is applied to the roll paper R at the same time as the conveyance operation is stopped. That is, even if the rotation speed of the winding motor is constant, the winding speed increases as the winding diameter increases, and the winding ends early.

  The time Tb from the winding start to the conveyance stop is set to a value calculated from the winding speed Vb and the maximum outer diameter Db that can be wound. As a result, the time Tb from the start of winding to the stop of conveyance can be shortened as long as no tension is applied to the roll paper R during the conveyance operation. That is, the tension start time can be controlled by the winding diameter.

  The above description is for a system that does not have a function of detecting the winding outer diameter D.

  If the winding outer diameter D is detected by a known detection function, the optimum time Tb from the start of winding to the stop of conveyance can be set by the following calculation.

Tb = δ / (Vb * D * π)
In this case, regardless of the outer diameter of the winding, when the outer diameter that can be wound is the maximum shown on the right side of FIG.

  Next, each operation of conveyance, printing, and winding will be described.

  FIG. 9 is a flowchart showing the relationship between the transport, printing, and winding operations. The flowchart of this application is implement | achieved when the control part 101 reads and runs the program required in order to perform the process of a flowchart.

  FIG. 9A is a flowchart showing an operation of performing one winding for one transport and printing.

  In S <b> 11, the control unit 101 drives the LF motor 8 and conveys the roll paper R by a predetermined pitch by the LF roller 9. In S12, the control unit 101 calculates a time Tb from the start of winding to the conveyance stop, and in S13, starts winding at the winding speed Vb within the calculated time Tb from the start of winding to the conveyance stop. To do. And before the LF motor 8 starts the next drive, the control part 101 stops the said winding. In S <b> 14, the control unit 101 drives the carrier motor 61 to scan the recording head 11 mounted on the carrier 12.

  In step S <b> 15, the control unit 101 drives the recording head to eject ink, and records an image for one line on the roll paper R. In S16, the control unit 101 determines whether predetermined printing is completed. If the printing is not completed, the control unit 101 returns to S11 and continues a series of operations. If the predetermined printing is completed, the printing and winding operations are ended there. In other words, in the example of FIG. 9A, the control unit 101 can cause the winding unit 71 to execute the roll paper winding process after S11 ends and until the next S11 is executed. It becomes.

  FIG. 9B is a flowchart illustrating an operation of performing winding after the conveyance S11 and the printing S14 and S15 are performed n times.

  That is, in the operation shown in FIG. 9A, one winding and printing are performed for one conveyance and printing, but in the operation shown in FIG. 9B, conveyance S11 and printing S14 and S15 are performed. Is performed n times (S17), and winding is executed.

  FIG. 10 is a timing chart showing each element and the state of the roll paper.

  As shown in FIG. 10, the winding start timing may be advanced in a range where no tension is applied to the roll paper R during the transport operation, and the winding may be started during the transport operation.

  Next, an example in which the time Tb from the start of winding to the conveyance stop and the time Ta when the LF roller conveys the roll paper are set to the same length (Tb = Ta) will be described.

  As in the case shown in FIG. 8, by increasing the winding start time, the winding is completed more quickly, and as a result, printing with a narrow print width can be handled. Here, the winding start time and the operation start time of the LF motor 8 are simultaneous, but the winding start time may be slightly delayed from the operation start time of the LF motor 8.

  Next, an example of calculating the time Tb from the start of winding to the stop of conveyance will be shown.

  The winding speed Vb is calculated based on the time Tb from the start of winding to the conveyance stop and the maximum outer diameter Db that can be wound.

The relationship between time Tb (sec) from winding start to conveyance stop, winding speed Vb (rps), winding maximum outer diameter Db (mm), winding amount Mb (mm) is as follows:
Tb * Vb * Db * π = Mb
It is. Assuming that the amount of slack δ generated by the conveyance of the roll paper R is equal to the winding amount Mb, the winding speed Vb is
Vb = Mb / (Tb * Db * π) = δ / (Tb * Db * π)
Since the winding start time and the operation start time of the LF motor 8 are simultaneous, Tb = Ta,
Vb = δ / (Ta * Db * π)
become.

  When the winding outer diameter is small, the tension acts on the roll paper R in the middle during non-conveyance (conveyance stop), but the tension acts as the winding outer diameter gradually increases. The starting point moves to the left. When the winding outer diameter reaches the maximum, the amount of looseness of the roll paper R due to the LF conveyance becomes the same as the amount of looseness due to the winding operation, and the looseness of the roll paper R due to the LF conveyance does not occur. Therefore, the tension acts on the roll paper R simultaneously with the stop of the conveying operation.

  Therefore, by setting the winding speed Vb to the value calculated based on the time Tb from the start of winding to the conveyance stop and the maximum outer diameter Db that can be wound, tension is applied to the roll paper R during the conveying operation. The winding speed Vb can be set within a range that does not exist.

  The above description is about a system that does not have a function of detecting the winding outer diameter D.

  If there is a function for detecting the winding outer diameter D, it is possible to set an optimum winding speed Vb according to the winding outer diameter D by the following calculation.

Vb = δ / (Ta * D * π)
In this case, regardless of the take-up outer diameter D, the tension is applied to the roll paper R at the same time as the conveyance operation is stopped, as in the case of the maximum take-up outer diameter shown on the right side of FIG.

  Next, each operation of conveyance, printing, and winding will be described.

  FIG. 11 is a flowchart showing operations of conveyance, printing, and winding.

  In S31, the control unit 101 calculates the winding speed Vb, and in S32, drives the LF motor 8 to convey the roll paper R by a predetermined pitch. In S33, the control unit 101 starts winding with the calculated winding Vb simultaneously with driving of the LF motor 8, and stops the winding operation before the LF motor 8 starts to drive next.

  In step S34, the control unit 101 drives the carrier motor 61 to scan the carrier 12 on which the recording head is mounted. In step S35, the control unit 101 drives the recording head to eject ink, and records an image on the roll paper R.

  In S36, the control unit 101 determines whether predetermined printing is completed. If the printing is not completed, the control unit 101 returns to S31 and continues the series of operations. If completed, the printing and winding operations are ended there.

  As described above, the winding tension is applied to the roll paper R during non-conveyance (conveyance stop) where the grip force of the LF roller 9 is strong. Therefore, the roll paper R is not slipped by the tension, and can be conveyed with high accuracy, and the joint between the prints is clean.

  The first embodiment is an embodiment that realizes an improvement in the conveyance accuracy of the roll paper R and an improvement in ink landing accuracy by applying a winding tension during non-conveyance (conveyance stop). Embodiment 2 of the present invention is an embodiment in which tension is applied to the roll paper R during conveyance (non-printing) to improve ink landing accuracy.

  When the winding unit winds up the roll paper R, after recording an image for one line by the forward or backward movement of the carrier 12, the roll paper R is fed by a predetermined pitch in the transport direction by the LF roller pair 9, 10. As a result, the roll paper R is loosened by the amount conveyed. Thereafter, when the roll paper is taken up by the take-up unit, the roll paper R is not loosened, and a predetermined tension acts on the roll paper R. There are two cases where this tension is applied: printing and non-printing.

  Strictly speaking, the roll paper R is often not a flat surface due to, for example, the roll paper R floating on the platen at the time of printing. Further, according to the tension acting on the roll paper R, the floating condition of the roll paper R also changes. The change in the posture of the roll paper R in the platen plane directly leads to the deviation of the ink landing position. More specifically, a change in posture in the vertical direction (floating) of the platen changes the flying distance (height) of the ink, so that the ink ejected from the head that scans at a constant speed shifts the landing position. In particular, the thin paper with low rigidity is easily changed by the tension change of the roll paper R, and the above-mentioned tendency is remarkable.

  Therefore, by performing the winding control so that the tension acts on the non-printing, the posture of the roll paper R does not change at least at the time of printing, so that ink landing at the assumed position is possible.

  Also, instead of winding up for each line of printing and transporting at a predetermined pitch, after one line printing and transporting at a predetermined pitch are repeated n times, the slack of the predetermined pitch × n times is rolled up. You may do it. However, in order to land the ink with high accuracy, it is necessary to set the timing at which the tension is applied during non-printing.

  Next, an outline of the winding operation will be described.

  FIG. 12 is a cross-sectional view showing a loose or stretched state of the roll paper R when the roll paper R is printed and wound.

  FIG. 13 is a timing chart showing the state of the roll paper R that changes according to the movement of each element.

  First, from the state in which the amount of slack is constant (FIGS. 12E and 13E), the amount of slack in the roll paper R is accompanied by the conveying operation of the LF motor 8 (FIGS. 12F and 13F). Gradually increases. The winding motor operates after a predetermined time, and the amount of looseness of the roll paper R decreases (FIGS. 12G and 13G). Note that the amount of slackness of the roll paper R is reduced because the rotation speed of the winding motor is faster than the rotation speed of the LF motor. When the looseness of the roll paper R disappears, the tension acts on the roll paper R (FIGS. 12H and 13H). Since the driving timing of each element is set so that the tension on the roll paper R is applied during non-printing, the posture of the roll paper R during printing is maintained constant, and thereby the ink landing accuracy Is secured.

  The second embodiment is effective when there is little influence on the transport force even when a tension is applied during transport, for example, when the clamping force of the LF roller pair is large. That is, even if tension is applied during conveyance, the conveyance accuracy can be ensured, and the roll paper is not taken up during non-printing, so that the landing accuracy can be ensured.

  The second embodiment is an embodiment in which the ink is landed with high accuracy so that the winding tension acts during non-printing.

  The third embodiment of the present invention is an embodiment in which the conveyance accuracy of the roll paper R is improved and the ink landing accuracy is improved by applying tension to the roll paper R during non-printing and non-conveyance.

  The winding operation in the third embodiment will be described.

  FIG. 14 is a timing diagram of the third embodiment.

  First, from the state (J) in which there is no slack, the amount of slack in the roll paper R gradually increases (K) in accordance with the transport operation of the LF roller 9 by driving the LF motor 8, and when the transport operation ends, the LF roller 9 The amount of slack that is transported by can be made. Thereafter, ink is ejected from the recording head 11 while moving the carrier, and a one-line image is printed (L) on the roll paper R. At the time of printing, no tension is applied to the roll paper R, but as shown in FIG. 14, the amount of slack is constant, so that ink can be landed at a desired position. Simultaneously with the end of printing, the take-up motor is driven to take the slack amount of the roll paper R (M). When the looseness of the roll paper R disappears, a tension acts on the roll paper R in the non-printing area (N).

  The tension acts on the roll paper R in an area where the roll paper R is not conveyed (non-conveyed). In this region, since the grip force of the LF roller 9 is strong, the roll paper R does not shift. Therefore, in the next one-line printing, there is no white streak between the lines, so that ink can be landed at a desired position, and the image is clearly connected. .

  By setting the drive timing of each element so that the tension on the roll paper R acts in the non-printing area and the non-transporting area, the ink landing accuracy is ensured.

  In the third embodiment, the driving range of the winding motor is set from the end of printing to the start of conveyance. However, if the tension on the roll paper R acts in the non-conveying area and the non-printing area, the start timing and end timing of the winding motor drive may be set slightly earlier.

  The following apparatus is suitable for this embodiment.

  In a printer that prints by reciprocating the head, in order to aim for higher image quality, it is common to provide a mode that prints only in one direction and does not print in the other direction. By doing so, the landing accuracy can be ensured by keeping the ink ejection angle constant, and the color reproducibility is improved by making the color superposition order constant. In this case, since printing is not performed in the other direction, the printing time tends to be extended. According to the present embodiment, during this non-printing operation, for example, the winding operation is performed in the first half of the non-printing operation and the transporting operation is performed in the second half of the non-printing operation, thereby eliminating unnecessary time delay.

  The function of the present embodiment can also be realized by the following configuration. That is, it is also achieved by supplying a program code for performing processing of the ink jet printer 1 of the present embodiment to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus executing the program code. In this case, the program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the program code also realizes the function of the present embodiment.

  Further, the program code for realizing the functions of the present embodiment may be executed by one computer (CPU, MPU), or may be executed by the cooperation of a plurality of computers. Also good. Further, the program code may be executed by a computer, or hardware such as a circuit for realizing the function of the program code may be provided. Alternatively, a part of the program code may be realized by hardware and the remaining part may be executed by a computer.

1 ... Inkjet printer,
2 ... Image recording unit,
9 ... LF roller,
10 ... Pinch roller,
R: Roll paper.

Claims (4)

A transport roller for transporting the roll paper, a recording head for recording on the roll paper transported by the transport roller, a carrier mounted on the recording head and moving in a direction intersecting the direction of transporting the sheet, A winding spool that winds up the roll paper on which recording has been performed by the recording head; and a transport operation that transports the roll paper by a predetermined amount by the transport roller; and the carrier that intersects when the transport roller is stopped In a recording apparatus that repeatedly performs a recording operation that moves in a direction and performs recording on the roll paper by the recording head,
When the transporting operation is performed by the transporting roller, the winding spool is not driven to drive the winding spool after the roll paper is loosened between the transporting roller and the winding spool. Control means for performing a winding operation for winding the roll paper, and the control means determines a timing for starting the winding operation based on an outer diameter of the roll paper wound on the winding spool. A recording apparatus.   When the outer diameter of the roll paper wound on the take-up spool is large, the control means delays the timing for starting the winding operation than when the outer diameter of the roll paper is small. The recording apparatus according to claim 1.   The recording apparatus according to claim 1, further comprising a paper supply spool for holding roll paper, wherein the roll paper is supplied from the paper supply spool to the transport roller.   The recording apparatus according to claim 1, wherein the recording head performs recording by discharging ink.

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