JP2007084225A - Recording medium carrying device, recording device and liquid jetting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further reduce kick-off phenomena at the rear end of paper, caused by a carriage driving roller and a carriage driven roller during executing edge-less printing, without lowering throughput. <P>SOLUTION: This recording medium carrying device holds paper P between the carriage driving roller 30 and the carriage driven roller 31 and carries the paper P with the rotation of the carriage driving roller 30. The carriage driven roller 31 is provided movably in a paper carrying direction and its opposite direction in a range where the paper P can be held between the carriage driving roller 30 and itself so that it can be moved in the opposite direction to the paper carrying direction by force received from the rear end of the paper P when the rear end of the paper P is removed from between the carriage driving roller 30 and the carriage driven roller 31. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention includes a transport driving roller that is rotationally driven and a transport driven roller that can freely rotate to sandwich the recording medium between the transport driving roller and transports the recording medium. The present invention relates to a recording medium transport apparatus and a recording apparatus including the recording medium transport apparatus. The present invention also relates to a liquid ejecting apparatus.

Here, the liquid ejecting apparatus uses an ink jet recording head, and is not limited to a recording apparatus such as a printer, a copying machine, and a facsimile machine that discharges ink from the recording head to perform recording on a recording medium. And a device that ejects a liquid corresponding to the application from a liquid ejecting head corresponding to the ink jet recording head to an ejected medium corresponding to a recording medium, and adheres the liquid to the ejected medium. .
In addition to the recording head, as a liquid ejecting head, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, and an electrode material (conductive paste) used for forming an electrode such as an organic EL display or a surface emitting display (FED) Examples thereof include an ejection head, a bioorganic matter ejection head used for biochip production, and a sample ejection head as a precision pipette.

  An example of the recording apparatus or the liquid ejecting apparatus is an ink jet printer. An ink jet printer includes an ink jet recording head that ejects ink toward a printing medium as an example of a recording medium or an ejection medium, and a platen that defines the position of the printing paper with respect to the ink jet recording head by supporting the printing paper from below. have. On the upstream side of the inkjet recording head in the printing paper conveyance path, conveyance means comprising a conveyance driving roller that is rotationally driven and a conveyance driven roller that sandwiches the printing paper between the conveyance driving roller. The printing paper is precisely fed to the area facing the ink jet recording head by the conveying means. The printed printing paper is discharged toward a stacker or the like by discharge means provided on the downstream side of the ink jet recording head.

  Here, when printing without margins on the printing paper, that is, when performing borderless printing, when the trailing edge of the printing paper comes out between the conveyance driving roller and the conveyance driven roller (nip point), A phenomenon (so-called “kicking phenomenon”) occurs in which the pressure of the printing paper by the conveyance driven roller acts to forcefully feed the printing paper in the paper conveyance direction, and the printing result is disturbed when this kicking phenomenon occurs. There is a case. Therefore, in the printing apparatus described in Patent Document 1, in order to alleviate the kicking phenomenon, the sheet conveyance speed when the trailing edge of the printing sheet comes out from the nip point between the conveyance driving roller and the conveyance driven roller is reduced. Yes.

JP 2005-8343 A

However, as described above, when the paper conveyance speed when the trailing edge of the printing paper leaves the nip point between the conveyance driving roller and the conveyance driven roller is lowered, there is a demerit that the throughput is lowered.
In recent years, in order to perform even higher image quality printing, printing paper with a coat layer (dedicated paper) for high-quality printing has become available. Along with the increase, as described above, there is a limit to the extent that the kicking phenomenon can be alleviated only by reducing the paper conveyance speed when the trailing edge of the printing paper comes out of the nip point between the conveyance driving roller and the conveyance driven roller. It has come to occur. In addition, in the above situation where higher quality printing is desired, further mitigation of the kicking phenomenon is desired.
Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to prevent the trailing edge kicking phenomenon caused by the conveyance driving roller and the conveyance driven roller when performing borderless printing without reducing the throughput. It is to further relax.

  In order to solve the above-described problems, a first aspect of the present invention includes: a conveyance drive roller that is rotationally driven; and a freely rotatable conveyance driven roller that sandwiches a recording medium between the conveyance drive roller. A recording medium transport apparatus configured to transport a recording medium, wherein the transport driven roller is moved when a rear end of the recording medium comes out between the transport driving roller and the transport driven roller. The recording medium is within a range in which the recording medium can be clamped between the conveyance driving rollers so that the recording medium can move in the direction opposite to the conveyance direction of the recording medium by a reaction force received from the rear end of the recording medium. It is characterized by being provided so as to be movable in the transport direction and the opposite direction.

  According to this aspect, the conveyance driven roller is provided so as to be movable in the conveyance direction of the recording medium and in the opposite direction within a range in which the recording medium can be clamped with the conveyance driving roller. When the rear end of the medium comes out between the transport driving roller and the transport driven roller, the rear end of the recording medium is not kicked by the transport driving roller and the transport driven roller. Is moved in the direction opposite to the conveyance direction of the recording medium. Therefore, the kicking phenomenon at the trailing edge of the recording medium can be prevented or reduced, and the recording quality disturbance due to the kicking phenomenon can be prevented or reduced.

  According to a second aspect of the present invention, there is provided a recording target, comprising: a transport driving roller that is rotationally driven; and a transport driven roller that is freely rotatable and sandwiches a recording medium between the transport driving roller. A recording medium conveyance device for conveying a medium, wherein the conveyance driven roller is attached to a holder member via a rotation shaft that penetrates the conveyance driven roller in an axial direction, and the conveyance driven roller is a recording medium The holder is configured to be movable in a direction opposite to the conveyance direction of the recording medium by a force received from the rear end of the recording medium when the rear end is pulled out between the conveyance driving roller and the conveyance driven roller. In the member, a clearance is provided between a bearing portion that pivotally supports the rotation shaft and the rotation shaft.

  According to this aspect, the conveyance driven roller can move in the direction opposite to the conveyance direction of the recording medium when the trailing end of the recording medium comes out between the conveyance driving roller and the conveyance driven roller. When the rear end of the medium comes out between the transport driving roller and the transport driven roller, the rear end of the recording medium is not kicked by the transport driving roller and the transport driven roller. Is moved in the direction opposite to the conveyance direction of the recording medium. Therefore, the kicking phenomenon at the trailing edge of the recording medium can be prevented or reduced, and the recording quality disturbance due to the kicking phenomenon can be prevented or reduced.

  Further, by forming a clearance between the rotation shaft of the conveyance driven roller and the bearing portion that supports the rotation shaft, the conveyance driven roller can be moved in the recording medium conveyance direction and in the opposite direction. Therefore, the recording medium conveying apparatus can be configured with a simple structure and at low cost.

  According to a third aspect of the present invention, in the second aspect, the two transport driven rollers are provided on one holder member via the one rotation shaft, and the bearing member includes the bearing portion. Are provided in a plurality so as to be located at the center of the rotation shaft and at both ends of the rotation shaft, and the amount of movement of the conveyance driven roller in the conveyance direction and in the opposite direction is determined by the rotation shaft. It is defined by the bearing part arrange | positioned at both ends.

  According to this aspect, the plurality of bearings that support the common rotation shaft of the two transport driven rollers are provided so as to be positioned at the central portion in the axial direction and at both ends, and the recording of the transport driven roller is performed. Since the amount of movement in the medium conveyance direction and in the opposite direction is defined by the bearing portions disposed at both ends of the rotation shaft, the rotation shaft swings around the bearing portion disposed at the center portion. Without rotating, the rotation axis of the two conveyance driven rollers can always be substantially parallel to the rotation axis of the conveyance drive roller, and the recording medium can be conveyed in an appropriate direction.

According to a fourth aspect of the present invention, in the third aspect, a bearing portion located at a central portion of the rotation shaft presses the rotation shaft toward the conveyance drive roller, and both ends of the rotation shaft are arranged. The bearing part located in the part is configured not to press the rotating shaft toward the transport driving roller.
According to this aspect, since only the bearing portion located at the central portion of the rotation shaft presses the rotation shaft toward the conveyance drive roller at one point, the bearing portions located at both ends of the rotation shaft. As compared with the case where the rotating shaft is pressed at two points toward the transport driving roller, the imbalance of the pressing load is less likely to occur, and the two transport driven rollers can be uniformly pressed toward the transport driving roller. it can.

  According to a fifth aspect of the present invention, there is provided a recording apparatus comprising a recording head for recording on a recording medium, the recording medium conveying apparatus according to any one of the first to fourth aspects. It is characterized by. According to this aspect, in the recording apparatus, it is possible to obtain the same operational effects as those of the first to fourth aspects described above.

  According to a sixth aspect of the present invention, there is provided a liquid ejecting head that ejects liquid onto the ejected medium, a transport driving roller that is provided on the upstream side of the liquid ejecting head and is driven to rotate, and the transport driving roller. A liquid ejecting apparatus that includes a transport driven roller that can freely rotate and sandwiches the ejected medium, wherein the transport driven roller has a rear end of the ejected medium between the transport driving roller and the transport driven roller. In the range in which the ejected medium can be clamped between the transport drive rollers so that the ejected medium can move in the direction opposite to the transport direction of the ejected medium by the force received from the rear end of the ejected medium. It is provided so as to be movable in the transport direction of the ejection target medium.

  According to a seventh aspect of the present invention, there is provided a liquid ejecting head that ejects liquid onto the ejected medium, a transport driving roller that is provided on the upstream side of the liquid ejecting head and is driven to rotate, and the transport driving roller. A transport driven roller that can freely rotate and sandwiches the ejected medium, wherein the transport driven roller is attached to the holder member via a rotation shaft that penetrates the transport driven roller in the axial direction. The rotating shaft is attached to the transport direction of the ejected medium by the force received from the rear end of the ejected medium when the rear end of the ejected medium comes out from between the transport driving roller and the transport driven roller. Is characterized in that a clearance is provided between the rotary shaft and a bearing portion that supports the rotary shaft so that the holder member can move in the opposite direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Hereinafter, an outline of an ink jet printer (hereinafter referred to as “printer”) 1 as an example of a recording apparatus and a liquid ejecting apparatus according to the present invention will be described first with reference to FIG. Here, FIG. 1 is a side sectional view of the paper conveyance path of the printer 1. In the following, the right direction (front side of the printer) in FIG. 1 is referred to as “downstream side” of the paper transport (feed) path, and the left direction (backward side of the printer) is referred to as “upstream side”.

  The printer 1 includes a feeding device 2 capable of setting recording paper (mainly cut sheet paper: hereinafter referred to as “paper P”) as an example of a recording medium and an ejection medium in an inclined posture at the rear portion, and the feeding device. 2, the paper P is fed toward a recording medium conveying means 4 as a “recording medium conveying apparatus” on the downstream side. The fed paper P is conveyed by the recording medium conveying means 4 to the recording means 3 on the downstream side, and recording is executed. Then, the sheet P on which recording is performed by the recording unit 3 is discharged to the front of the apparatus by the recording medium discharge unit 5 on the downstream side.

Hereinafter, components on the paper conveyance path of the printer 1 will be described in more detail. The feeding device 2 includes a hopper 11, a feeding roller 12, a retard roller 13, and a return lever 14 in a frame 22.
The hopper 11 is formed of a plate-like body, and is provided so as to be able to swing around an upper swing fulcrum (not shown). By swinging, the paper P supported in an inclined posture is fed onto the hopper 11. The pressure contact posture that presses against the roller 12 and the separation posture that separates from the feeding roller 12 are switched. The feeding roller 12 has a substantially D shape when viewed from the side, and feeds the uppermost sheet P pressed by the arc portion to the downstream side, while the recording medium after the sheet P is fed. During conveyance of the paper P by the conveyance means 4, the flat portion is controlled to face the paper P as shown in the figure so as not to cause a conveyance load.

  The retard roller 13 has an outer periphery formed of an elastic material, is provided so as to be able to press contact with the arc portion of the feed roller 12, and is provided in a state where a predetermined rotational resistance (torque) is applied. When the retard roller 13 is fed with only one sheet without the double feeding of the paper P, a torque greater than the rotational resistance is applied to the retard roller 13, so that the retard roller 13 is driven to rotate with respect to the feed roller 13. (Clockwise in FIG. 1).

On the other hand, when there are a plurality of sheets P between the feeding roller 12 and the retard roller 13, the friction coefficient between the sheets is lower than the friction coefficient between the sheet P and the retard roller 13. No torque greater than the rotational resistance is applied to 13, and the motor 13 stops without rotating. Therefore, this prevents the next and subsequent sheets P, which are to be double-fed by the uppermost sheet P to be fed, from traveling from the retard roller 13 to the downstream side, thereby preventing double feeding.
The return lever 14 is provided so as to be swingable when viewed from the side of the feeding path of the paper P. By swinging, the return lever 14 returns the next and subsequent paper P about to be double fed onto the hopper 11. Play.

  Next, a detecting means (not shown) for detecting the passage of the paper P is formed between the feeding device 2 and the recording medium conveying means 4, and a paper P feeding posture is formed and the paper P is fed. A guide roller 26 is provided for preventing contact with the feed roller 12 and reducing the transport load. Here, the guide roller 26 is pivotally supported at the upstream end of the paper guide top 24 so as to be freely rotatable.

The recording medium conveying means 4 as a recording medium conveying device provided on the downstream side of the feeding device 2 includes a conveyance driving roller 30 that is rotationally driven by a motor, and a driven rotation in pressure contact with the conveyance driving roller 30. It is configured to include a transport driven roller 31 that moves.
The transport driving roller 30 is provided with an adhesion layer formed by substantially uniformly dispersing wear-resistant particles on the outer peripheral surface of a metal shaft extending in the paper width direction, and the transport driven roller 31 has a low friction material such as an elastomer on the outer peripheral surface. A plurality of the drive driving rollers 30 are arranged in the axial direction. The transport driven roller 31 will be described in detail later.

The paper guide upper 24 that pivotally supports the transport driven roller 31 is provided so as to be swingable about the shaft 24a when the shaft 24a is pivotally supported by the main frame 23, as seen from the side of the paper transport path. By means of a coil spring 25 as means, the conveyance driven roller 31 is urged in a direction in which it is pressed against the conveyance drive roller 30.
The sheet P that has reached the recording medium conveying unit 4 rotates to the recording unit 3 on the downstream side when the conveyance driving roller 30 rotates while being nipped (clamped) by the conveyance driving roller 30 and the conveyance driven roller 31. It is conveyed.

  The recording unit 3 includes an inkjet recording head (hereinafter referred to as “recording head”) 36 and a paper guide lower portion 37 provided to face the recording head 36. The recording head 36 is provided at the bottom of the carriage 33. The carriage 33 is driven to reciprocate in the main scanning direction by a drive motor (not shown) while being guided by a carriage guide shaft 34 extending in the main scanning direction. In addition, the carriage 33 mounts an independent ink cartridge (not shown) for each of a plurality of colors in an internal space covered by the cover 35, and supplies ink to the recording head 36.

  Under the paper guide 37 that defines the distance between the paper P and the recording head 36, ribs 51, 52, and 53 are formed on the surface facing the recording head 36, and concave portions 54 and 55 for discarding ink are formed. In this case, the ink ejected to the area deviated from the edge of the paper P is thrown away into the recesses 54 and 55, and so-called borderless printing is performed in which printing is performed without margins on the edge of the paper P.

  Subsequently, a guide roller 43 and a recording medium discharge unit 5 are provided on the downstream side of the recording head 36. The guide roller 43 functions to prevent the paper P from being lifted from the paper guide bottom 37 and to keep the distance between the paper P and the recording head 36 constant. The recording medium discharge means 5 includes a discharge drive roller 41 that is rotationally driven by a motor (not shown), and a discharge driven roller 42 that rotates in contact with the discharge drive roller 41. In the present embodiment, a plurality of discharge driving rollers 41 are provided in the axial direction of a shaft body that is made of a rubber roller and is rotationally driven.

  Further, the discharge driven roller 42 is formed by a toothed roller having a plurality of teeth on the outer periphery, and a plurality of discharge driven rollers 42 are provided on the discharge frame Assy 45 having a long shape in the main scanning direction so as to correspond to the plurality of discharge driving rollers 41. . The paper P on which recording has been performed by the recording means 3 is discharged forward by the rotation of the discharge drive roller 41 while being nipped by the discharge drive roller 41 and the discharge driven roller 42.

  The printer 1 is configured to be able to perform ink jet recording directly on a label surface of an optical disc (thin plate-like body) such as a CD-R in addition to a cut sheet. The optical disc is conveyed through a linear tray conveyance path in the printer 1 in a state where a plate-shaped tray (not shown) is set. The tray is manually inserted into the tray conveyance path toward the rear side (upstream side) of the printer 1 while being supported by a tray guide 7 provided in front of the printer 1, and is further sub-recorded by the recording medium conveyance unit 4. Scanned.

  The above is the configuration of the printer 1, and the recording medium transport unit 4 will be described in detail below with reference to FIGS. 2 is an external perspective view of the paper guide top 24, the transport driven roller 31, and the transport drive roller 30. FIG. 3 is an explanatory view showing the kicking phenomenon of the rear end of the paper P and the principle of means for preventing it. Is a cross-sectional view of the paper guide top 24 and the transport driven roller 31, and FIGS. 5 to 7 are cross-sectional views of the same side.

As shown in FIGS. 2 and 4, in the present embodiment, two transport driven rollers 31 are supported by one paper guide 24. Specifically, the two conveyance driven rollers 31 are arranged at a predetermined interval in the axial direction thereof, and one rotation shaft 32 penetrates the two conveyance driven rollers 31 and the rotation shaft 32. Is pivotally supported on the paper guide 24.
The rotary shaft 32 is constrained so that both shaft ends thereof do not move in the axial direction by the bearing portions 24c and 24c, and is constrained not to move upward by the bearing portion 24b at the central portion thereof.

  One end 25 b of the coil spring 25 that urges the transport driven roller 31 toward the transport drive roller 30 is hooked on the main frame 23 (FIG. 1), and the other end 25 a extends to the bearing portion 24 b on the paper guide top 24. Thus, the bearing portion 24 b is urged toward the conveyance drive roller 30. As a result, the rotation shaft 32 is biased toward the transport drive roller 30 at the central portion thereof, that is, the bearing portion 24 b, thereby pressing the two transport driven rollers 31 toward the transport drive roller 30.

  In this way, only the bearing portion 24b located at the center portion of the rotation shaft 32 presses the rotation shaft 32 toward the conveyance drive roller 30 at one point, so that the bearing portions positioned at both ends of the rotation shaft 32 are used. Compared to the case where the rotating shaft 32 is pressed at two points toward the transport driving roller 30 by 24c and 24c, the imbalance of the pressing load is less likely to occur, and the two transport driven rollers 31 are uniformly transferred to the transport driving roller 30. Can be pressed.

  Next, the kicking action of the trailing edge of the paper P by the carry driving roller 30 and the carry driven roller 31 and the preventing action of the kicking action obtained by the present invention will be described with reference to FIG. 3A-1 to 3A to 3C show the behavior of the paper P when a conventional transport driven roller (indicated by reference numeral 310) that does not have a kick-off function preventing function is used. FIG. -3 show the behavior of the paper P (and the transport driven roller 31) when the recording medium transport means 4 according to the present invention is used. In addition, white blank arrows in the figure indicate the conveyance direction of the paper P.

  FIG. 3A-1 shows a state before the sheet P (the front end) enters between the conveyance driving roller 30 and the conveyance driven roller 310. In this state, the conveyance driven roller 310 is the conveyance driving roller. 30 is in direct contact. FIG. 3A-2 shows a state in which the paper P enters between the transport driving roller 30 and the transport driven roller 310 (a state in which the paper P is pressed). The transport driven roller 310 is displaced upward.

  FIG. 3A-3 shows the moment when the trailing edge of the paper P has slipped out between the transport driving roller 30 and the transport driven roller 310, and when the trailing edge of the paper P slips out from the nip point of both rollers. Because the transport driven roller 310 is displaced downward by the thickness of the paper P and directly contacts the transport drive roller 30 again, the rear end of the paper P is downstream from between the transport drive roller 30 and the transport driven roller 310. Force (direction indicated by the black arrow in the figure) is received. If such “kicking phenomenon” occurs and the recording is being performed on the paper P, the printing result will be disturbed. That is, the printing result is disturbed when borderless printing is performed on the trailing edge of the paper P.

  On the other hand, in FIGS. 3B-1 to 3B showing the principle of the present invention, the transport driven roller 31 is provided so as to be movable in the transport direction (Y direction) of the paper P and in the opposite direction. Therefore, as shown in FIGS. 3B-1 and 3B, in the state where the paper P is transported, the transport driven roller 31 is moved to the transport direction (downstream side) at the position where the transport driven roller 31 is displaced from the transport driving roller 30. Clamp between them.

  When the trailing edge of the sheet P is pulled out between the conveyance driving roller 30 and the conveyance driven roller 31, the trailing edge of the sheet P is not kicked by both rollers as shown in FIG. The transport driven roller 31 moves in the direction opposite to the transport direction of the paper P (direction indicated by the black arrow) by the force received from the rear end of the paper P. Therefore, the kicking phenomenon at the trailing edge of the paper P can be prevented or reduced, so that the print quality disturbance due to the kicking phenomenon can be prevented or reduced.

  Hereinafter, a configuration in which the transport driven roller 31 can be moved in the paper transport direction and in the opposite direction will be described. As shown in FIG. 4, the rotation shaft 32 penetrating the two transport driven rollers 31 in the axial direction is constituted by a bearing portion 24b disposed at the center portion thereof and bearing portions 24c and 24c disposed at both end portions. Although it is pivotally supported, as shown in FIGS. 5A and 5B, a clearance is formed between the rotating shaft 32 and the bearing portions 24b and 24c. 5A shows a cross section at the position of the bearing portion 24b, and FIG. 5B shows a cross section at the position of the bearing portion 24c.

For example, in this embodiment, the diameter (D) of the rotating shaft 32 is 1.94 (mm), the inner dimension (W ₁ ) of the bearing portion 24b is 2.4 (mm), and the inner dimension of the bearing portion 24c ( W ₂ ) is formed at 2.0 (mm). That is, a clearance of 0.46 (mm) is formed at the center of the shaft, and a clearance of 0.06 (mm) is formed at both ends of the shaft.

  Since the clearance is formed in this way, the rotation shaft 32, that is, the transport driven roller 31 is movable in the paper transport direction and the opposite direction (left and right direction in FIG. 5). As shown in FIG. 6, the rotation shaft 32 is stabilized in a state where it is in contact with the downstream inner wall 24 d of the bearing portion 24 c by the force received from the paper P, and the paper P is pinched between the transport driving roller 30.

  When the rear end of the paper P is pulled out between the transport driving roller 30 and the transport driven roller 31, the rotation shaft 32 (the transport driven roller 31) is a bearing by the force received from the rear end of the paper as shown in FIG. Moving to the upstream inner wall 24e side of the portion 24c (in the direction of the black arrow), the kicking action of the paper P is prevented or reduced.

  As described above, by forming a clearance between the bearing portion 32 and the bearing portions 24c and 24c (inside) supporting the bearing portion 32, the conveyance driven roller 31 is moved in the paper conveyance direction and in the opposite direction. Therefore, the recording medium conveying means 4 can be configured with a simple structure and at a low cost.

Since the clearance (W ₂ ) in the bearing portion 24c that pivotally supports the rotation shaft 32 at both ends is smaller than the clearance (W ₁ ) in the bearing portion 24b that pivotally supports the rotation shaft 32 at the center, the conveyance driven roller The amount of movement of 31 in the paper conveyance direction and the opposite direction is defined by the bearing portions 24c and 24c arranged at both ends of the rotation shaft 32.

  Accordingly, for example, the rotation shaft 32 does not swing around the bearing portion 24 b disposed at the center portion, for example, and the rotation axis lines of the two conveyance driven rollers 31 are set to the rotation axis line of the conveyance drive roller 30. Therefore, the paper P can be conveyed in an appropriate direction.

  In the embodiment described above, by forming a clearance between the bearing portion 32 and the bearing portions 24c and 24c that pivotally support the bearing portion 32, the conveyance driven roller 31 is moved in the paper conveyance direction and in the opposite direction. However, any configuration may be used as long as it is based on the principle of the present invention described with reference to FIGS.

  For example, by providing a clearance between the rotation shaft 32 and the shaft hole of the transport driven roller 31, the transport driven roller 31 may be provided so as to be movable in the paper transport direction and the opposite direction, or the paper guide. By providing a clearance between the upper 24 shaft 24a (FIG. 1) and a bearing portion that supports the shaft 24a, the transport driven roller 31 may be provided so as to be movable in the paper transport direction and in the opposite direction. However, the movement range of the conveyance driven roller 31 needs to be within a range in which the paper P can be pinched with the conveyance driving roller 30.

  In particular, in this embodiment, the rotation center of the conveyance driven roller 31 is arranged slightly downstream in the sheet conveyance direction with respect to the rotation center of the conveyance drive roller 30, so that the sheet P is sent out by both rollers. Is directed to the platen 56, that is, the paper P is pressed against the platen 56, thereby preventing the paper P from being lifted from the platen 56 and obtaining an appropriate recording quality. Therefore, the moving range of the transport driven roller 31, particularly the position of the transport driven roller 31 during transport of the paper P (state shown in FIG. 6), does not lose the orientation of the paper P to the platen 56 as described above. It is preferable to do.

1 is a side sectional view of an ink jet printer according to the present invention. FIG. 3 is a perspective view of a transport driven roller and a transport driving roller according to the present invention on paper guidance. FIG. 3 is an explanatory diagram showing the principle of a kicking phenomenon at the rear end of the paper and a means for preventing it. FIG. 4 is a cross-sectional view of a paper guide and a conveyance driven roller. FIG. 4 is a side sectional view of a paper guide and a conveyance driven roller. FIG. 4 is a side sectional view of a paper guide and a conveyance driven roller. FIG. 4 is a side sectional view of a paper guide and a conveyance driven roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer, 2 feeding apparatus, 3 recording means, 4 recording medium conveyance means, 5 recording medium discharge means, 11 hopper, 12 feeding roller, 13 retard roller, 14 paper return lever, 23 main frame, 24 paper 24a shaft, 24b bearing section, 24c bearing section, 25 coil spring, 26 guide roller, 30 transport drive roller, 31 transport driven roller, 32 rotation shaft, 33 carriage, 34 carriage guide shaft, 35 cover, 36 recording Head, 37 Platen, 41 Ejection drive roller, 42 Ejection driven roller, 43 Guide roller, 45 Ejection frame Assy, P Recording paper

Claims (7)

A transport drive roller that is driven to rotate;
A recording medium conveying apparatus for conveying a recording medium, comprising: a freely driven conveying driven roller that sandwiches the recording medium with the conveyance driving roller;
The transport driven roller is opposite to the transport direction of the recording medium due to the force received from the rear end of the recording medium when the trailing end of the recording medium comes out between the transport driving roller and the transport driven roller. The recording medium is provided so as to be movable in the conveyance direction of the recording medium and in the opposite direction within a range in which the recording medium can be clamped between the conveyance driving rollers.
A recording medium conveying apparatus characterized by the above. A transport drive roller that is driven to rotate;
A recording medium conveying apparatus for conveying a recording medium, comprising: a freely driven conveying driven roller that sandwiches the recording medium with the conveyance driving roller;
The transport driven roller is attached to the holder member via a rotation shaft that penetrates the transport driven roller in the axial direction,
The transport driven roller is opposite to the transport direction of the recording medium due to the force received from the rear end of the recording medium when the trailing end of the recording medium comes out between the transport driving roller and the transport driven roller. In the holder member, a clearance is provided between the rotating shaft and a bearing portion that supports the rotating shaft.
A recording medium conveying apparatus characterized by the above. In Claim 2, two said conveyance follower rollers are provided in one said holder member via one said rotation axis,
In the holder member, a plurality of the bearing portions are provided so as to be positioned at a center portion of the rotation shaft and both ends of the rotation shaft,
The amount of movement of the transport driven roller in the transport direction and in the opposite direction is defined by bearing portions disposed at both ends of the rotation shaft.
A recording medium conveying apparatus characterized by the above. 4. The bearing portion according to claim 3, wherein a bearing portion located at a central portion of the rotation shaft presses the rotation shaft toward the transport drive roller, and bearing portions located at both ends of the rotation shaft are the rotation shaft. Is configured so as not to be pressed toward the conveyance drive roller.
A recording medium conveying apparatus characterized by the above. A recording apparatus comprising a recording head for recording on a recording medium, comprising the recording medium conveying apparatus according to any one of claims 1 to 4.
A recording apparatus. A liquid ejecting head for ejecting liquid onto the ejected medium;
A conveyance drive roller provided on the upstream side of the liquid jet head and driven to rotate;
A liquid driven apparatus including a freely driven conveyance driven roller that sandwiches a medium to be ejected with the conveyance driving roller,
The transport driven roller is opposite to the transport direction of the ejected medium due to the force received from the rear end of the ejected medium when the rear end of the ejected medium comes out between the transport driving roller and the transport driven roller. In such a way that the medium to be ejected can be pinched with the transport driving roller, so that the medium to be ejected is movable in the transport direction and the opposite direction.
A liquid ejecting apparatus. A liquid ejecting head for ejecting liquid onto the ejected medium;
A conveyance drive roller provided on the upstream side of the liquid jet head and driven to rotate;
A liquid driven apparatus including a freely driven conveyance driven roller that sandwiches a medium to be ejected with the conveyance driving roller,
The transport driven roller is attached to the holder member via a rotation shaft that penetrates the transport driven roller in the axial direction.
The rotating shaft is in a direction opposite to the transport direction of the ejected medium due to the force received from the rear end of the ejected medium when the rear end of the ejected medium comes out between the transport driving roller and the transport driven roller. In the holder member, a clearance is provided between the rotating shaft and a bearing portion that supports the rotating shaft.
A liquid ejecting apparatus.

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