KR100860183B1 - Transport device, recording apparatus and liquid ejecting apparatus - Google Patents

Abstract

A method of controlling the conveying amount of a pair of first rollers and a pair of second rollers, wherein the pair of first rollers can pick up the medium so as to transport the medium in the conveying direction, and the pair of second rollers The medium can be picked up so as to transport the media and is disposed on the downstream side of the pair of first rollers in the conveying direction, and recording is carried out on the media by a recording head disposed between the pair of first rollers and the pair of second rollers. Performed: performing a first correction on the conveyance amounts of the pair of first rollers and the pair of second rollers; And the medium is released from being picked up by the pair of first rollers from a state where the length between the nip point picked up by the pair of first rollers and the rear end of the medium is a predetermined length. And performing a second correction on the conveying amount of the at least one pair of first rollers until the losing state.

Description

TRANSPORTER, RECORDING DEVICE AND LIQUID SPRAYER {TRANSPORT DEVICE, RECORDING APPARATUS AND LIQUID EJECTING APPARATUS}

1 is a side view schematically showing the internal structure of a recording apparatus according to an embodiment of the present invention.

2 is a graph showing a conveyance error when a general sheet is conveyed with the related art.

3 is a graph showing a conveyance error when thick paper is conveyed with the related art.

4 is a graph showing a transfer error before correction is executed in the second embodiment.

FIG. 5 is a chart showing data of a transfer error before correction is executed in the second embodiment.

6 is a chart showing data of a transfer error before correction is executed in the second embodiment.

7 is a chart showing data of a transfer error before correction is executed in the second embodiment.

8 is a chart showing data of a transfer error before correction is executed in the second embodiment.

Fig. 9 is a graph showing the transfer error after the correction is executed in the second embodiment.

FIG. 10 is a chart showing data of a transfer error after correction is performed in the second embodiment.

FIG. 11 is a chart showing data of a transfer error after correction is executed in the second embodiment.

12 is a chart showing data of a transfer error after correction is performed in the second embodiment.

FIG. 13 is a chart showing data of a transfer error after correction is executed in the second embodiment.

The present invention relates to a method of controlling a conveying amount of a recording medium in which a recording medium is conveyed in a state of being picked up between a pair of conveying rollers and a pair of ejecting rollers. A pair of conveying rollers for conveying the medium, a pair of ejecting rollers for discharging the recording medium on which recording is performed by the recording head, a conveying apparatus, a recording apparatus with the conveying apparatus, and a liquid ejecting apparatus with the conveying apparatus. It is about.

An example of a liquid ejecting apparatus is a recording apparatus such as an inkjet recording apparatus which ejects ink from a recording head acting as a liquid ejecting head onto a recording medium such as a recording sheet to perform recording on the recording medium, copier, facsimile and the like. And apparatuses for causing the ejected liquid corresponding to the characteristic to adhere the liquid to the ejected material by using ink and others from the liquid ejecting head corresponding to the above-described recording head onto the ejected materials corresponding to the recording medium. . Moreover, an example of the liquid ejecting head is, in addition to the above-described recording head, forming a color material ejecting head, an electrode of an organic EL display, or an electrode of a surface emitting display (FED) used to manufacture a color filter of a liquid crystal display. Electrode material (conductive paste) spray head used to make a test, bio-organic material spray head used to manufacture a biochip, a sample spray head for spraying a sample such as a precision pipette, and the like. Include.

As an example of the inkjet recording apparatus or ink jetting apparatus, an inkjet printer is provided. The inkjet printer is configured to supply a supply unit for supplying recording media stacked in a downstream transport path, a transport unit for transporting the supplied recording media to a recording position, a recording unit for recording on the recording medium, and the recording medium for recording being performed. And an outlet part. Among them, the conveying section has a pair of conveying rollers for conveying the recording medium from the supply section to the recording section at a downstream position of the recording section. Moreover, the recording portion has a recording head for ejecting ink onto the recording medium. In addition, the discharge portion has a pair of discharge rollers for discharging the recording medium on the downstream side of the recording portion. The pair of feed rollers and the pair of discharge rollers each have a drive roller and a driven roller. Each drive roller of the pair of feed rollers and the pair of discharge rollers is rotatably driven by a common or independent motor. The amount of rotation of the drive motor is controlled by the control unit so that the recording medium can be conveyed to the recording section at a desired conveyance amount.

However, when the type of recording medium is different, the recording medium is different in thickness, material, and weight of the recording medium. As a result, the coefficient of friction between each driven feed roller, driven discharge roller (hereinafter referred to as roller) and the recording medium changes. Thus, slipping can occur between the rollers and the recording medium for each type of recording medium. If slippage occurs between the respective rollers and the recording medium, even if each roller is driven to rotate by a predetermined amount, the recording medium is not conveyed by the slip by the target conveyance amount. By that, recording quality can be degraded. In particular, in inkjet printers in recent years, image quality has been greatly improved and photographic image quality has been improved, requiring a paper transfer precision of several micrometers. If the precision of paper transfer of several micrometers is not satisfied, a line called a 'band' may occur in the recorded picture. Therefore, when the sheet conveying accuracy is lowered, this significantly affects the recording result.

In this case, the 'stripe development' is carried out if the printing and paper (recording medium) conveying are continuously performed by the recording head and nozzles for one line of printing to perform a single line of printing. It is referred to as a phenomenon in which clogging or blank space occurs between subsequent print lines due to a change in precision or a change in the position of the recording head and nozzle. Therefore, print quality is degraded not only in black-and-white printing but also in color printing.

Therefore, in order to solve the above problem, a raster recording apparatus is disclosed in JP-A-5-305747 or JP-A-8-72341. The raster recording apparatus measures the actual print length R '(printing result) with respect to the predetermined print length R (target value). In addition, since the correction coefficient values are calculated from the lengths R and R ', the feed amount can be corrected in the current print job by using the correction coefficients.

Moreover, in general, the structures of the conveying roller and the ejecting roller are different from each other in terms of materials. Therefore, the conveyance error when the recording medium is conveyed by the conveying roller and the conveyance error when the recording medium is conveyed by the ejecting roller are different from each other. The structure corresponding to the structure of the recording apparatus disclosed in JP-A-2004-123313 is obtained in view of the above points. In the recording apparatus disclosed in JP-A-2004-123313, in which a plurality of pairs of rollers are provided and the combination of the roller pairs for conveying the recording medium changes, the conveying amount of the recording medium can be appropriately corrected.

However, the above-described correction alone cannot prevent the "stripes" phenomenon that occurs. For example, after the rear end of the recording medium passes through the conveying part, the friction between the rear end of the recording medium and the conveying path until the recording medium is placed in a state of being pinched between the conveying rollers, that is, until the rear end passes completely. The change in the rolling area (contact area) of the recording medium with respect to the feed roller, i.e., the change in the rolling angle, is caused by a change in the band-like phenomenon caused by Not sufficiently considered For this reason, depending on various papers (thick papers with high rigidity), the conveyance amount of the recording medium may be different until the rear end passes completely. As a result, a band phenomenon may occur.

In this case, 'passing through the supply section' means that the recording medium passes through an area that is nipped between the supply roller and the conveying path of the supply section.

Therefore, it is an object of the present invention to generate according to each of various recording media until a part of the recording medium disposed upstream of the pair of feed rollers in the conveying direction passes completely through the pair of feed rollers. It is an object of the present invention to provide a conveying amount control method, a conveying apparatus, a recording apparatus, and a liquid ejecting apparatus capable of eliminating errors in the conveying amount of a recording medium.

According to the present invention, in order to achieve the above object, a method of controlling the conveying amount of a pair of first rollers and a pair of second rollers, the pair of first rollers to pick up the medium to convey the medium in the conveying direction A pair of second rollers may pick up the medium to convey the medium and are disposed downstream of the pair of first rollers in the conveying direction, the pair of first rollers and the pair of second rollers The recording is performed on the medium by a recording head disposed in between:

Perform a first correction on the conveyance amounts of the pair of first rollers and the pair of second rollers; And

The medium is released from being picked up by a pair of first rollers from a state where the length between the nip point picked up by a pair of first rollers and the rear end of the medium is a predetermined length. Up to a state, performing a second correction on the feed amount of the at least one pair of first rollers.

In this case, the 'predetermined length' is such that, on the upstream side of the conveying direction of the medium picked up by the pair of first rollers, the strong reverse tension generated by the friction between the medium and the conveying path is reduced. It means the size of the area. In other words, the 'predetermined length' is represented by the size of the rear end of the medium remaining on the upstream side of the pair of first rollers when the rear tension is reduced. Moreover, the 'predetermined length' is determined by the various media, the shape of the conveying path, and the angular difference between the conveying path and the conveying direction defined by the pair of first rollers, which is determined evenly. It doesn't work.

According to the invention, in order to achieve the above object, and also as a method of controlling the conveying amount of a pair of first rollers and a pair of second rollers, a pair of first rollers are used to convey the media in the conveying direction. Can pick up, a pair of second rollers can pick up the medium to convey the medium and are disposed downstream of the pair of first rollers in the conveying direction, a pair of first rollers and a pair of second Recording is performed on the medium by a recording head disposed between the rollers:

Perform a first correction on the conveyance amounts of the pair of first rollers and the pair of second rollers; And

At least one pair of pairs from the time the contact area where the medium remains in contact with one of the pair of first rollers begins to change, from the time the medium is picked up by the pair of first rollers to the time it is released Performing a second correction on the feed amount of the first roller.

According to the invention, in order to achieve the above object, there is provided a transport apparatus:
A pair of first rollers capable of picking up the medium to convey the medium in a conveying direction;

delete

A pair of second rollers capable of picking up the medium to convey the medium and disposed downstream of the pair of first rollers in a conveying direction;

A first controller capable of performing a first correction on the conveyance amounts of the pair of first rollers and the pair of second rollers; And

From the state where the length of the nip point picked up by the pair of first rollers and the rear end of the medium is a predetermined length, from the picked-up state by the paired first rollers And a second controller capable of performing a second correction on the feed amount of the at least one pair of first rollers.

The recording apparatus with a conveying apparatus may be disposed between the pair of first rollers and the pair of second rollers, and may include recording means capable of recording information on the medium.

The recording apparatus may further include a conveying path, wherein the medium is conveyed, is disposed upstream of the pair of first rollers in the conveying direction, and has a shape that deforms the conveyed medium.

The recording apparatus has a medium transported, disposed upstream of a pair of first rollers in a conveying direction, and connected to a first zone and the first zone, the first zone and a pair of first rollers. It further comprises a transport path including a second zone disposed between. The inclination of the first zone may be greater than the inclination of the second zone.

The liquid ejecting apparatus with a conveying apparatus is arranged between a pair of first rollers and a pair of second rollers, and includes ejecting means capable of ejecting liquid toward the medium.

<Detailed Description of the Preferred Embodiments>

[First Embodiment]

Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a side view schematically showing the internal structure of a recording apparatus according to an embodiment of the present invention.

As shown in Fig. 1, the recording apparatus 100 includes a sheet conveying apparatus 110 for conveying sheets P1 to P3. The paper conveying apparatus 110 feeds the paper P1 to P3 to the recording unit 140 by the supply unit 120 for supplying the paper (not shown) stacked on the transport path 161. A recording apparatus (140) for recording on the sheets P1 to P3 conveyed by the conveying unit 130, the sheets P1 to P3 recorded by the recording unit 140, and the like. It has a discharge part 150 to discharge from 100.

The supply unit 120 has a supply roller 121 having a D-shaped side, and supplies paper P1 to P3 to the transfer path 161. The papers P1 to P3 supplied to the transfer path 161 are picked up between a pair of transfer rollers 131 provided from the transfer unit 130, and the recording unit located downstream of the transfer direction. Is transferred to 140. The pair of feed rollers 131 has a feed drive roller 132 driven by a drive motor (not shown), and a feed driven roller 133 driven by the feed drive roller 132 to rotate. In addition, the recording unit 140 is provided in a platen (143) for supporting the paper (P1 to P3) transferred from the bottom by the transfer unit 130, and in a position opposite to the platen (143) Has a recording head 141. In addition, in the recording head 141, a nozzle opening row 142 for ejecting ink is formed, and the recording head 141 can eject ink onto the sheets P1 to P3 to perform recording thereon. have. In this case, a predetermined interval, i.e., a so-called platen interval or paper gap PG (hereinafter referred to as platen interval) is provided between the recording head 141 and the platen 143.

In addition, the sheets P1 to P3 on which recording is performed are picked up between the pair of discharge rollers 151 provided at the discharge unit 150 and are discharged from the recording unit 140. The pair of discharge rollers 151 has a discharge drive roller 152 driven by a drive motor (not shown), and a discharge driven roller 153 driven by the discharge drive roller 152 to rotate. In addition, the axis of the feed roller pair 131 and the axis of the discharge roller pair 151 are inclined to form a 'reverse V shape' in the figure. The reason why it is inclined to form the inverted V shape is that the papers P1 to P3 facing the recording head 141 are lifted from the platen 143, and the paper P1 to P3 and the recording head 141 are separated from each other. This is to prevent the gap, that is, the platen gap PG, from changing. The auxiliary roller 154 provided between the recording head 141 and the discharge roller pair 151 can further prevent the sheets P1 to P3 from rising.

Moreover, the sheets P1 to P3 and their rear ends P1 'to P3' represent the state of the position where the sheets are conveyed.

2 is a graph showing a conveyance error when a general sheet is conveyed in the related art. 3 is a graph showing a conveyance error when thick paper is conveyed in the related art. The graphs shown in Figs. 2 and 3 show a state in which no correction is made for the conveyed amount when the sheet is conveyed.

In Figures 2 and 3, the vertical axis of the graph represents the difference between the logical value of the 'feed amount' and the actual feed amount to which the sheets P1 to P3 are to be conveyed. A positive value means that the paper is fed by a feed amount that is larger than the logical value of the feed amount, and a negative value means that the paper is fed by a feed amount that is smaller than the logic value due to slip or back tension. It means to be. The horizontal axis indicates the number of times the sheet is conveyed from the leading edge of the sheet (feed times, number of passes). The solid line of the graph indicates the conveyance amount of the paper on the 80th digit side, and the dotted line indicates the conveyance amount of the paper on the 1st digit side. Here, the 80th digit side means the left in the conveying direction, the first digit side means the right in the conveying direction.

In this case, 'normal paper' refers to paper having a thickness of about 0.1 mm, and 'thick paper' refers to paper having a thickness of 0.2 mm or more.

In the conveying state, the term 'feeding' refers to conveying one sheet of paper, that is, one pass, obtained by the conveying operation, and the amount of conveying of one sheet of paper is about 1.4 mm.

Moreover, the 'difference between the logical value and the actual feed amount' is the difference between the feed amount and the logical feed amount accumulated by 18 passes of the graph's vertical axis (1 to 18, 2 to 19, 3 to 20, ...). This is indicated by referring to the difference, and a zero value on the vertical axis represents a logical feed amount. In addition, the reason why the transfer amount is accumulated is as follows. Since the difference between the logic value and the feed amount is very small, it is very difficult to see the difference between the logic value and the feed amount. Therefore, due to the accumulation of the conveyed amount, the difference including the logical value and the conveyed amount becomes prominent.

Moreover, in this embodiment, the length of P2 is about 40 mm.

In addition, the distance between the nip point of the feed roller pair 131 and the nip point of the feed roller 121 is about 70 mm. In addition, in the inclined surface of the conveying path 161, on the feed roller side where the rear end of the paper is not in contact with the gentle inclined surface of the conveying path 161, and the feed roller side where the rear end of the paper is in contact. The boundary between the steeply inclined surfaces of the transfer path 161 is provided about 30 mm upstream from the nip point of the transfer roller pair. In addition, the angular difference between the conveying direction formed by the conveying roller pair and the gentle inclined surface is about 5 degrees. On the other hand, the angular difference between the feed direction formed by the feed roller pair and the steep inclined surface is about 8 degrees.

Moreover, the distance of the nip point of the said feed roller from the said pair of feed rollers, and the structure of a feed path like the shape and angle of a feed path are not limited to the above-mentioned embodiment.

As shown in Fig. 2, on the 1st digit side and the 80th digit side, the same level is maintained from 1 to 170 passes on the horizontal axis, and each level varies from 171 passes.

In this case, in 1 to 170 passes in the horizontal axis, the paper is picked up and conveyed between the conveying roller pair 131 and the ejecting roller pair 151 shown in FIG. 1, and this state is referred to as conveying state A. . On the other hand, from the passage 171 on the horizontal axis, the rear end portions P1 'to P3' of the paper pass through the transfer roller pair 131, and they are picked up and conveyed only between the pair of discharge rollers 151 ( Discharged). This state is referred to as transfer state B. In addition, passage 141 on the horizontal axis indicates a state in which the rear end portions P1 'to P3' of the paper pass through the feed roller 121 of the feeder 120. In particular, it represents the position P2 'shown in FIG. In addition, pass 171 on the horizontal axis indicates a state where the rear ends P1 'to P3' of the paper pass through the pair of feed rollers 131.

The reason for the level change from passage 171 on the horizontal axis is because the feed state changes. The specific reasons are as follows.

In general, since the feed drive roller 132 and the discharge drive roller 152 are each formed of different materials, an error in the feed amount when the paper is conveyed only by the feed roller pair 131 causes the paper to be discharged roller pair 151. It is different from the error of the feed amount when it is fed with only. Thus, in the conveying state A in which the paper is conveyed by the conveying roller pair 131 and the ejecting roller pair 151 and in the conveying state B in which the sheet is conveyed by the ejecting roller pair 151 only, between the logical value and the actual conveying amount The difference is that the error levels are different.

Moreover, in the conveying state B rather than the conveying state A, the level of the difference between the logical value and the actual conveying amount increases, but this is due to the material of the paper, the material of the conveying drive roller 132 and the material of the ejection drive roller 152. will be. The level of difference between the logical value and the actual feed amount in the transfer state B is not necessarily higher than that in the transfer state A. In other words, the level of the difference between the logical value and the actual feed amount in the transfer state B may be lower than that in the transfer state A.

As shown in Fig. 3, on the 1st digit side and the 80th digit side, the same level is maintained from 1 to 140 passes on the horizontal axis, and the level varies from pass 141 in the same way. In this case, in 1 to 50 passes in the horizontal axis, the levels of the 1st digit side and the 80th digit side are slightly different from each other, but the difference between the levels of the 1st digit side and the 80th digit side is not considered here. As described above, passage 141 on the horizontal axis indicates a state when the rear end of the sheet passes through the feed roller 121 of the feeder 120. In particular, it represents the position of P2 'shown in FIG.

3 is a graph showing a state in which thick paper is conveyed. Therefore, when the sheet is deformed or bent by the conveying path 161, the rear ends P2 'to P3' come into contact with the conveying path 161, and strong back tension is generated. Although the rear tension occurs on normal paper, when compared with the normal paper, the strong rear tension is generated on thick paper. In addition, when the rear end moves from the rear end P1 'to the rear end P3', friction between the rear end P3 'and the conveying path 161 is eliminated, resulting in a decrease in the rear tension.

In particular, in the state of the paper P1, since the upstream side is sufficiently long from the feed roller pair 131, the paper P1 is deformed by the feed path 161. That is, since the rear end P1 'is pushed downward by the conveying path 161, friction occurs at the rear end P1' and generates rear tension. In the case of the thick paper, the rear tension is stronger than that in the general case.

In addition, the paper is conveyed to the position of the paper P2 by the feed roller pair 131. At the same time, as mentioned above, the axis of the feed roller pair is inclined inward in the drawing. Therefore, at the position of the paper P2, the conveyance direction from the conveying roller pair 131 and the direction of the paper P2 are the same line. That is, the rear end P2 'is brought into contact with the conveying path 161 without being pushed downward by the conveying path 161, and the rear tension is rapidly reduced. As a result, since the rear tension is reduced, the paper is reliably conveyed by the feed roller pair 131.

Then, the sheet is conveyed to the position of sheet P3 by the transfer roller pair 131. At the same time, since the rear end P3 'is far from the conveying path 161, no rearward tension is generated. That is, the strength of the rear tension changes rapidly near the position of the sheet P2.

Further, when the position of the rear end changes from the rear end P1 'to the rear end P3', the rolling angle of the paper with respect to the feed drive roller is increased. That is, since the rolling amount (rolling area, contact area) is increased, slippage is less likely to occur.

In particular, when the sheet is conveyed by the transfer roller pair 131 from the position of the sheet P1 to the position of the sheet P2, the rolling angle between the sheet and the conveying drive roller 132 changes. At the same time, since the conveying drive roller 132 is provided on the lower side, the rolling angle increases step by step.

In addition, the sheet is conveyed by the transfer roller pair 131 to the position of the sheet P3. At the same time, in the sheet upstream of the conveying direction from the conveying roller pair, as described above, the axis of the conveying roller pair is inclined, so that the inclination of the sheet P2 is maintained. However, the thick paper is thicker than the normal paper, so that the rear end P3 'is lowered in comparison with the normal paper. Therefore, the rolling angle of the paper with respect to the feed drive roller 132 is increased. As a result, slippage is less likely to occur between the paper and the transfer drive roller 132. Therefore, the paper can be reliably conveyed by the transfer roller pair 131.

Thus, the level of passes 141 to 170 on the horizontal axis is higher than the level of passes 1 to 140 on the horizontal axis. That is, in the case of thick paper, a phenomenon which occurs rarely in ordinary paper occurs in 141 to 170 passes in the horizontal axis. Therefore, even in the same conveyance state A, the level of a vertical axis changes large.

In the conveying state B after passing 171 times on the horizontal axis, the level changes with respect to the conveying state A, similar to the case of the general paper shown in FIG.

In addition, the level of 1 to 170 passes of the general paper shown in FIG. 2 and the level of 1 to 140 passes of the thick paper shown in FIG. 3 are different because the material is different depending on the type of paper. This is because there is a difference between the material of the drive roller 132 and the discharge drive roller 152, for example, a friction coefficient.

The paper conveying apparatus 110 has a logical value and actual value displayed on the vertical axis of the graph according to the type of paper in the state where the paper is conveyed by the conveying roller pair 131 and the ejecting roller pair 151, that is, the conveying state A. A first correction is performed to correct the entire level of the difference between the feed amounts. According to the specific correction, whenever the paper of several passes to tens of passes (1 pass = about 1.4 mm) is conveyed, the correction is performed by the control unit 162, which is provided by the feed drive roller or the like. One step (approximately 5.9 μm), which is the minimum resolution (resolution, precision) of the encoder, is added or subtracted, and all levels of the vertical axis are made of approximately zero values of the logical axis.

As a result, the level of 1 to 140 passes in the horizontal axis of FIG. 3 is raised, thereby making a difference between the actual value and the logical value indicated by the vertical axis, approximating zero. However, if only this level is raised, the value between passes 141 and 170 in the horizontal axis may be displaced from the logic value on the vertical axis.

Thus, in addition to the first correction, in the feed state A, a second correction for correcting the partial level of the difference between the logical value and the actual feed amount, indicated by the vertical axis of the graph, has passed through the supply unit 120. The rear end portions P1 'to P3' of the subsequent sheet of paper are carried out according to the type of sheet until they pass through the pair of feed rollers 131 (141 to 170). Specific features of the second correction method are the same as those of the first correction method.

As a result, the level of passages 141 to 170 in the horizontal axis of FIG. 3 decreases, and the difference between the actual feed amount and the logical value represented by the vertical axis approaches zero.

In the present embodiment, in the paper feed amount control method, which is a feed amount control method of a recording medium, the papers P1 to P3 include a pair of feed rollers 131 and a pair of discharge rollers. 151 are conveyed in a state of being picked up, and a pair of feed rollers 131 feeds the sheet from the supply section 120 where the sheets P1 to P3 are stacked to the recording head 141, and a pair The eject roller 151 ejects the sheets P1 to P3 in which recording is performed by the recording head 141. The method comprises the steps of performing a first correction per sheet of various kinds of paper to correct the feed amount of each feed drive roller 132 and each discharge drive roller 152, and between the feed roller pairs 131 After the starting of the conveyed paper, the lengths P1 to P3 of the paper are 'predetermined size' (from the feed roller pair 131 to the rear end P2) on the upstream side in the feed direction from the feed roller pair 131. With respect to the feed amount of the transfer drive roller 132 and the discharge drive roller 152 in a state where the paper is further conveyed and released from being picked up between the pair of feed rollers 131. Performing a second correction according to each sheet of the branch type.

For example, in the second correction, the rear end portion P1 is changed from a state in which the strength of the rear tension generated when the rear end portions P1 'to P3' of the paper are in contact with the conveyance path 161 changes. 'To P3') can be carried out according to the various types of respective sheets with respect to the feed amount of the feed drive roller 132 and the discharge drive roller 152 from the state picked up between the pair of feed rollers to the unwinded state. have. In order to reduce the rear tension, the amount of paper conveyed in the changing region (in Figure 3, 141 to 170 passes in the horizontal axis) is passed through the region (in Figure 3, 1 to 140 passes in the horizontal axis) before the rear tension is changed. Compared with the feed rate at, it is increased. Since the increased conveying amount is corrected by the second correction, the conveying amount of the paper is on the upstream side in the conveying direction from the conveying roller pair 131 after the conveying of the paper picked up between the conveying roller pair 131 starts. From the state in which the lengths P1 to P3 of the paper have a 'predetermined size', the paper can be further changed from being picked up and unrolled from being picked up between the feed roller pair 131. As a result, the 'band shape' can be prevented.

In addition, in the present embodiment, the second correction is performed by the feed roller pair 131 according to various kinds of papers with respect to the feed amount of the feed drive roller 132 and the discharge drive roller 152. When the upstream side P1 to P3 in the conveying direction of the paper picked up between the conveying roller pair 131 is moved by the conveying roller pair 131, between the conveying drive roller 132 and the sheets P1 to P3. From the state in which the rolling angle of starts to change, the paper may be further conveyed and then uncollected from being picked up between the conveying roller pair 131. In this case, when the paper is fed from the position of the paper P1, since the rolling angle between the paper and the feed drive roller 132 changes, in order to make the start timing of the second correction faster, the second The start timing of the correction may be set to start from pass 131 on the horizontal axis in FIG. 3.

As a result, from the state where the rolling angle between the sheets P1 to P3 and the transfer driving roller 132 starts to change, the sheet is further conveyed and released from being picked up between the pair of transfer rollers 131. Until the state, it is possible to stabilize the feed amount of the sheets P1 to P3 by the transfer driving roller 132 and the discharge driving roller 152.

Further, in the present embodiment, the second correction is that the feed path 161 for feeding the papers P1 to P3 from the feeder 120 to the feed roller pair 131 is provided between the feed roller pair 131. And it may be formed to deform the paper (P1 to P3) picked up between the discharge roller pair 151. In particular, the transport path 161 has a 'V' shape. The conveying path 161 has a surface that is gently inclined on the side of the conveying roller pair which does not come in contact with the rear end of the sheet, and has a surface that is sharply inclined on the side of the feed roller that the rear end comes in contact with. That is, the transfer path 161 is formed so that the amount of friction between the transfer path and the rear end of the paper is changed.

In this embodiment, the first correction is performed in the conveying state A when the sheet is conveyed by the conveying roller path and the ejecting roller pair. However, it may be carried out in a conveying state in which the sheet is conveyed by only one of the conveying roller pair and the ejecting roller pair.

Further, in this embodiment, the second correction is performed with respect to the feed amount of the transfer drive roller and the discharge drive roller. However, since the change of the conveying amount occurs on the upstream side due to the nip point of the conveying roller pair, the second correction may be performed only for the conveying amount of the conveying drive roller. Also, the second correction is referred to as the correction added to the first correction. However, the first correction may be performed before the second correction is performed and the third correction (= first correction + second correction) may be performed independently.

Moreover, the conveying drive roller may be disposed on the lower side, but may also be disposed on the upper side. In addition, the conveying path from the supply part to the conveying roller pair is configured to proceed downward, but may also be configured to proceed upward.

Second Embodiment

Next, a second embodiment will be described. In the second embodiment, actual steps for performing correction will be described.

FIG. 4 is a graph showing a transfer error before correction is performed in the second embodiment. The vertical axis represents the cumulative value 17 passes of the difference between the logical value and the actual feed amount, and the horizontal axis represents the number of feeds. 5 to 8 show a chart showing data of a transfer error before the correction is performed. FIG. 5 shows the 50 pass data in 1 pass, FIG. 6 shows the 100 pass data in 51 pass, FIG. 7 shows the 150 pass data in 101 pass, and FIG. 8 is 151 The data from the first pass is divided into 192 passes.

The steps are as follows.

1.Capture pitch data (raw data), which is the amount of paper conveyance in which no correction is performed (referred to as (A), the second and third lines from the left in FIGS. 5 to 8). .

2. Transition from the feed logic to the difference (referred to as (B), fourth and fifth lines from left in FIGS. 5 to 8).

3. Accumulated by 17 passes to obtain a correction amount per inch (denoted as (C), sixth and seventh rows from the left in FIGS. 5-8).

4. Determine the area needed to make a correction for the trailing end (backward correction area) based on the inflection point of the data (pass 122 times as shown in FIG. 4).

5. Calculate the average of 17 passes that accumulate in passes 1-121 and 122-166, and each include a difference between them.

6. Conversion in 1/5760 inch increments (feed accuracy).

Here, it is assumed that the standard feed amount in. Is 43/720 = 1516.9 (mu m). In addition, in the above-described first embodiment, the accumulation of the conveying amount is accumulated 18 times, the conveying precision is 1/4320 inch, one step = 5.9 (μm), and the standard conveying amount is 41/720 (actually 1.4 (mm)). The same) and the trailing end region passes 141 through 170 times. However, in the second embodiment, the accumulation of the feed amount is accumulated 17 passes, the feeding precision is 1/5760 inch, 1 step = 4.4 (μm), and the standard feed amount is 43/720 (substantially equal to 1516.9 (μm), About 1.5 (mm)) and the trailing end region is a passing region from 122 to 166. This difference is due to the model difference of the paper conveying apparatus 110.

"41" and "43" used in the above calculation of the standard feed amount are selected such that the periodic unevenness and wood grain texture are not generated in the image (image quality) with improved values based on the head precision of the recording head. "720" is a standard value of Seiko Epson Corporation. Since the nozzle pitch of the recording head is 90 dpi, 120 dpi and 180 dpi, the denominator is 360, 720, and 1440. These values are standard values.

The steps will be described in more detail.

According to the first step, raw data, which is pitch data, is captured as shown in the second and third rows from the left in (A), FIGS. 5 to 8.

Next, according to the second step, the difference between the raw data captured in the first step and the standard feed amount of 1516.9 (μm) is shown in the fourth and fifth lines from the left in (B), FIGS. 5 to 8. As obtained.

According to a third step, the differences are accumulated by passing 17 times as shown in (C), sixth and seventh rows from the left in FIGS. 5 to 8.

For example, the cumulative value of the first line in pass 1 is obtained by summing the difference between the raw data and the transfer logic of passes 1 through 17.

According to the fourth step, based on the raw data A shown in Figs. 4 to 8, the rear end of the paper is moved between the feed roller pairs from the passage 122 where the area for correction for the rear end is the change point of the data. It is determined by the area of passage 166 which is released from the picked up.

Further, according to the fifth step, 3.1 (μm) is obtained by calculating the average of the 17 pass accumulation values of 1 to 121 passes, and 26.0 (μm) is the average of the 17 pass accumulation values from 122 to 166 passes. It is obtained by calculating Then, the difference between the average of the 17 pass accumulation values in the 1st to 121th passes and the average of the 17 pass accumulation values in the 122 to 166 passes is obtained as shown in the following equation.

3.1 (μm)-26.0 (μm) = -22.9 (μm)

According to a sixth step, the value is converted in units of 1/5760 inches.

-22.9 (μm) /25.4 × 5760/1000 = -5.2

Therefore, a correction of -5/5760 inches per inch is made in the area of passages 122 through 161. Indeed, a correction of "-1" is provided five independent times in separate means for a one-inch feed that is substantially equal to seventeen passes. In particular, since 17 divided by 5 is 3.4, the correction is performed in passes 4, 7, 11, 14 and 17 which are integer number passes obtained by approximating the multiple number of values.

Fig. 9 shows a graph showing the transfer error after the rear end correction (corresponding to the second correction described in the first embodiment) is performed. The vertical axis represents the accumulated 17 passes of the difference between the logical value and the actual feed amount, and the horizontal axis represents the number of feeds. 10 to 13 show charts showing data of a transfer error after the correction is performed. 10 shows data divided into 1 pass through 50 passes, FIG. 11 shows data divided into 51 passes through 100 passes, and FIG. 12 shows data divided into 101 passes through 150 passes. And FIG. 13 shows data divided into passes 151 through passes 193.

The cumulative value of 17 passes is obtained by the method described above.

The paper conveying apparatus 110 in which the data shown in FIGS. 9 to 13 are collected is the same as the paper conveying apparatus 110 in which the data shown in FIGS. 4 to 8 are collected, and the rear end correction is performed or There is a difference between them.

As shown in Figs. 9 to 13, the rear end correction is performed, whereby the level of the feed amount in passes 122 to 161 corresponding to the data area before the rear end of the paper passes through the feed roller pair 131 Create and approximate to a logical value.

In addition, this invention is not limited to the Example mentioned above. Various changes and modifications may be made without departing from the spirit and scope of the invention as set forth in the appended claims. It goes without saying that variations and modifications are included within the scope of the present invention.

As described above, the present invention is a recording issued according to each of various recording media until a part of the recording medium disposed upstream of the pair of feed rollers in the feed direction passes completely through the pair of feed rollers. A conveying amount control method, a conveying apparatus, a recording apparatus, and a liquid ejecting apparatus can be provided so that errors in the conveying amount of the medium can be eliminated.

Claims (7)

A pair of first rollers (feed rollers) capable of picking up the medium to feed the medium in the conveying direction; A pair of second rollers (discharge rollers) which can pick up the medium so as to transport the media and are disposed on the downstream side of the pair of first rollers (feed rollers) in the conveying direction; A pair of third rollers (feed rollers) capable of supplying the stacked media in a conveyance path, and arranged upstream of the pair of first rollers (feed rollers) in a conveying direction; A first controller capable of performing a first correction to bring the actual feed amount close to a logic value in a state where the medium is conveyed by a pair of first rollers (feed rollers) and a pair of second rollers (discharge rollers). ; And After the medium picked up and conveyed by the pair of first rollers (feed rollers) reaches a predetermined position, the medium is further conveyed and released from the nip point by the pair of first rollers (feed rollers). And a second controller capable of performing a second correction on the level of the feed amount corrected by the first correction, according to the type of medium, to make a correction closer to a logic value. Conveying device. The method of claim 1, The predetermined position at which the medium arrives is a position at which a rear end of the medium is removed from the third roller (feed roller). The method of claim 1, The predetermined position at which the medium reaches the transfer device is a position in which a rolling angle with respect to the first roller (feed roller) fluctuates on the upstream side of the pair of first rollers (feed roller). . A conveying device according to claim 1; And And recording means disposed between the pair of first rollers (feed rollers) and the pair of second rollers (discharge rollers), the recording means capable of recording information on the medium. The method of claim 4, wherein And the conveying path has a shape in which a medium is conveyed, disposed upstream of a pair of first rollers (feeding rollers) in the conveying direction, and deforms the conveyed medium. delete A conveying device according to claim 1; And And a dispensing means disposed between the pair of first rollers (feed rollers) and the pair of second rollers (discharge rollers) and capable of injecting liquid toward the medium.

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