JP2006247932A - Carrying device for medium to be recorded, recording device, and liquid jetting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further soften the kicking phenomenon of the rear end of a paper by a paper carrying means when a boundary-less printing is executed, without decreasing the throughput. <P>SOLUTION: This carrying device 20 is constituted by comprising a carrying driven roller 21 which is rotation-driven, and a freely rotatable carrying following roller 22 which pinches the recording paper P together with the carrying driven roller 21. In the carrying device 20, a flange section 23 is provided on the shaft end of the carrying driven roller 21. When the carrying following roller 22 is pressed to the flange section 23, a space b which is smaller than the thickness (a) of the recording paper P is formed between both rollers. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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 from the nip point between the conveyance driving roller and the conveyance driven roller, the conveyance driving roller and the conveyance driven roller. A phenomenon (so-called “kicking phenomenon”) occurs in which the pressure between the printing papers causes the printing paper to be sent out vigorously downstream, and the printing result may be disturbed when this kicking phenomenon occurs. 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 sheet conveying speed when the trailing edge of the printing sheet moves out of the nip point between the conveying driving roller and the conveying 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 further alleviate the phenomenon of kicking the trailing edge of the sheet by the sheet conveying unit when performing borderless printing without reducing the throughput. It is in.

  In order to solve the above-described problem, a first aspect of the present invention includes: a conveyance driving roller that is rotationally driven; and a freely rotatable conveyance driven roller that sandwiches a recording medium between the conveyance driving roller. A recording medium transporting apparatus configured to transport a recording medium, wherein a gap smaller than the thickness of the recording medium to be transported is formed between the transport driving roller and the transport driven roller. It is characterized by that.

  According to this aspect, the thickness is smaller than the thickness of the recording medium to be transported between the transport driving roller that is rotationally driven and the freely driven transport driven roller that sandwiches the recording medium between the transport driving roller. Since the gap is formed, when the leading end of the recording medium enters between the transport driving roller and the transport driven roller, the recording medium is securely clamped by both rollers, and the transport driving roller rotates. And then conveyed downstream. Next, when the trailing edge of the recording medium moves out of the nip point between the transport driving roller and the transport driven roller, the outer peripheral surface of the transport driven roller and the outer peripheral surface of the transport drive roller are close to each other, but between the two rollers. In the first place, since a gap is formed, the outer peripheral surfaces of both rollers do not contact each other. In other words, even if the thickness of the recording medium increases, the kicking phenomenon when the trailing end of the recording medium comes out of the nip point between the transport driving roller and the transport driven roller without causing a decrease in throughput. Can be effectively mitigated.

According to a second aspect of the present invention, in the first aspect, the conveyance drive roller is formed by forming a high friction layer on an outer peripheral surface of a shaft body extending in a width direction of the recording medium, and the high friction layer. A flange portion having an outer diameter larger than the outer diameter of the roller in the portion where the high friction layer is formed is provided at the shaft end portion which is a non-forming portion, and the transport driven roller extends in the width direction of the recording medium. The gap is formed by a shaft body and the shaft end portion being in pressure contact with the flange portion.
According to this aspect, since the gap between the transport driving roller and the transport driven roller is formed directly by the flange, by managing the outer diameter of the flange, the transport drive roller and the transport driven roller Can be easily and precisely defined, and the gap can be stably maintained over a long period of time.

According to a third aspect of the present invention, in the second aspect, the flange portion is integrally formed by cutting on the shaft body that constitutes the transport driving roller.
According to this aspect, since the flange portion is integrally formed by cutting on the shaft body constituting the transport driving roller, the flange portion is provided with a simple structure and at low cost. Can do.

According to a fourth aspect of the present invention, in the second aspect, the flange portion is formed separately from the shaft body constituting the transport driving roller, and is detachably provided at a shaft end of the shaft body. It is characterized by being.
According to this aspect, the flange portion is formed separately from the shaft body constituting the transport driving roller, and is provided detachably at the shaft end of the shaft body. By exchanging, the gap between the transport driving roller and the transport driven roller can be easily adapted to the thickness of the recording medium to be transported.

According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the transport driven roller is urged toward the transport driving roller at a position in pressure contact with the flange portion. Features.
According to this aspect, since the transport driven roller is urged toward the transport driving roller at a position where it is in pressure contact with the flange portion, the transport driven roller is not bent, and the gap is formed. While being able to make it uniform in the axial direction of the said conveyance drive roller and the said conveyance follower roller, it can maintain stably over a long period of time.

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

  According to a seventh aspect of the present invention, there is provided a liquid ejecting head that ejects liquid onto the ejection target 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 configured to include a freely driven transport driven roller that sandwiches the ejected medium, in a state where the ejected medium does not exist between the transport driving roller and the transport driven roller. A gap smaller than the thickness of the medium to be transported is formed between the transport driving roller and the transport driven roller.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is a schematic side sectional view of an ink jet printer (hereinafter referred to as “printer”) 1 as an example of “recording apparatus” and “liquid ejecting apparatus” according to the present invention, and FIG. 2 is a recording target according to the present invention. FIG. 3A is a cross-sectional view of a transport apparatus 200 according to the prior art, and FIG. 3B is a cross-sectional view of the transport apparatus 20 according to the present invention. 4A, 4 </ b> B, and 4 </ b> C are cross-sectional views of the transport apparatus 200 (upper stage) according to the related art and the transport apparatus 20 (lower stage) according to the present invention, and the state of transport of the recording paper P is shown. It is explanatory drawing which shows transition. In the following, the upstream side (left side of FIGS. 1, 3 and 4) of the paper transport path (sub-scanning direction) is simply referred to as “upstream side”, and the downstream side of the paper transport path (right side of FIGS. 1, 3 and 4). ) Is simply referred to as “downstream”.

  First, the overall configuration of the printer 1 will be outlined with reference to FIG. The printer 1 is configured as a small size suitable for recording on a recording sheet P such as a postcard having a relatively small size or an L size, as an example of “recording medium” or “jetting medium”. . Further, the printer 1 according to the present embodiment is a so-called printer exclusively for photographic printing, which is configured on the assumption that thick recording paper having a coat layer is used as the recording paper P.

  A feeding device 2 is provided at the rear of the printer 1. The feeding device 2 includes a hopper 10, a feeding roller 11, a friction separating material 13, and a paper return lever 12. The hopper 10 is oscillated and driven by a driving means (not shown) around the oscillating fulcrum 10a to support the recording paper P in an inclined posture and press the recording paper P against the feeding roller 11 when the recording paper P is fed. .

  The feeding roller 11 has a substantially D shape when viewed from the side, and a rubber material is wound around the outer periphery thereof. The feeding roller 11 is selectively rotated when a sheet is fed by a driving motor (not shown). At the time of paper feeding, the uppermost sheet of the recording paper P pressed against the feeding roller 11 by the circular arc portion is fed to the downstream side, and when the paper feeding is completed, the conveyance operation by the downstream conveyance driving roller 21 is performed. At this time, control is performed so that a flat portion in a substantially D shape in a side view is opposed to the friction separating member 13 so as not to cause a conveyance load. Note that a roller indicated by reference numeral 14 is a freely rotatable idle roller, and is rotated in contact with the recording sheet P being conveyed so that the recording sheet P being conveyed does not contact the feeding roller 11 to cause a conveyance load. .

  A friction separating material 13 is provided at a position facing the feeding roller 11. The friction separating material 13 is pressed against the arc portion of the feeding roller 11 during paper feeding to form a pressure contact, whereby the uppermost recording paper P to be fed and the next order to be double fed. The subsequent recording paper P is separated. Further, a paper return lever 12 is provided at a position facing the feeding roller 11. The paper return lever 12 is provided so as to be able to swing around a swinging fulcrum 12a. During the one rotation operation of the feeding roller 11, the paper return lever 12 is temporarily set so as to open the feeding path of the recording paper P from the standby state shown in FIG. By falling and rising again as shown in FIG. 1, the next and subsequent recording sheets P that are about to be double fed are returned onto the hopper 10.

  The above is the feeding device 2, and a paper detector 17 including a lever 15 and a detection unit 16 is provided between the feeding roller 11 and the transport driving roller 21 on the downstream side of the feeding device 2. It has been. The lever 15 is provided so as to be able to oscillate about the oscillating shaft 15a, and the upper part from the oscillating shaft 15a is configured to come into contact with the recording paper P to be fed. The detection unit 16 is an optical sensor, and when the lower part of the lever 15 enters the detection unit 16 as shown in the figure, the light from the light emitting unit to the light receiving unit is blocked, and the recording paper P is not loaded. A passing state is detected. When the lever 15 swings with the passage of the recording paper P, the lower portion of the lever 15 from the swinging shaft 15a is disengaged from the detecting unit 16, thereby detecting the passage of the leading edge of the recording paper P. It can be done. Further, when the trailing edge of the recording paper P passes, the lower end portion of the lever 15 enters the detection unit 16 again, whereby the passage of the trailing edge of the recording paper P can be detected.

  Next, on the downstream side of the paper detector 17, a recording medium conveyance device (hereinafter referred to as “conveyance device”) 20 including a conveyance driving roller 21 and a conveyance driven roller 22 is provided. . The transport drive roller 21 is rotationally driven by a drive motor (not shown), and the transport driven roller 22 sandwiches the recording paper P with the transport drive roller 21 and is driven to rotate as the recording paper P is transported. Then, the recording paper P fed by the feeding roller 11 is sandwiched between the transport driving roller 21 and the transport driven roller 22, and the transport driving roller 21 is driven to rotate to an area facing the recording head 26. Be transported. The transport device 20 including the transport drive roller 21 and the transport driven roller 22 will be described in detail later.

  Next, an inkjet recording head (hereinafter referred to as “recording head”) 26 and a platen 28 are provided on the downstream side of the conveying device 20 so as to face each other. The recording head 26 is provided at the bottom of the carriage 25, and performs recording by ejecting (jetting) ink droplets as an example of a liquid toward the recording paper P. The carriage 25 is reciprocated in the main scanning direction by the power of a motor (not shown) while being guided by a carriage guide plate 27 extending in the main scanning direction. The platen 28 defines the gap between the recording paper P and the recording head 25 by supporting the recording paper P from below.

  A recording medium discharge device (hereinafter referred to as “discharge device”) 29 including a discharge driving roller 29, a discharge driven roller 30, and a discharge auxiliary roller 32 is provided on the downstream side of the recording head 26. It has been. The discharge drive roller 30 is rotationally driven by a drive motor (not shown), and the discharge driven roller 31 is driven to rotate in contact with the discharge drive roller 30. The recording sheet P on which recording has been performed is discharged toward a stacker (not shown) by being nipped by these rollers. A discharge auxiliary roller 32 provided on the downstream side of the discharge drive roller 30 is rotationally driven in synchronization with the discharge drive roller 30, and the rear end of the recording paper P sent out from the discharge drive roller 30 and the discharge driven roller 31. Is surely dropped toward a stacker (not shown).

The above is the general configuration of the printer 1, and the conveyance device 20 will be described in detail below with reference to FIGS.
2 and 3B, a transport driving roller 21 constituting the transport device 20 according to the present invention has a high friction layer 21a formed on the outer peripheral surface of a metal shaft extending in the width direction of the recording paper P. In addition, a flange portion 23 having an outer diameter larger than the outer diameter of the roller in the portion where the high friction layer 21a is formed (the portion where the recording paper P is pressed) is formed at both shaft end portions which are portions where the high friction layer 21a is not formed. 23 is provided. Note that the flange portions 23 and 23 are integrally formed by cutting on a metal shaft body constituting the transport driving roller 21 in the present embodiment.

  On the other hand, the transport driven roller 22 is formed by a metal shaft extending in the width direction of the recording paper P in the present embodiment, and is provided so as to be able to approach and separate from the transport drive roller 21 and is also not shown. It is provided in a state of being urged toward the transport driving roller 21 by means. Accordingly, the recording paper P that has entered between the transport driving roller 21 and the transport driven roller 22 is sandwiched between the two rollers as shown in FIG. Precision feed to the side.

  Here, both shaft ends of the transport driven roller 22 are provided so as to be in pressure contact with flange portions 23 and 23 provided at both shaft ends of the transport drive roller 21 as shown in detail in FIG. As a result, a gap is formed between the outer peripheral surface of the transport driving roller 21 and the outer peripheral surface of the transport driven roller 22 in the state where the recording paper P does not exist. In FIG. 3, symbol a indicates the thickness of the recording paper P, and symbol b indicates a gap formed between the outer peripheral surface of the transport driving roller 21 and the outer peripheral surface of the transport driven roller 22 by the flange portions 23, 23. Show. 2 to 4, the thickness of the recording paper P is exaggerated for convenience of explanation.

  Hereinafter, the function and effect produced by the gap b will be described. FIG. 3A shows a conventional conveying device 200 in which the flange portions 23 are not provided for comparison with the conveying device 20 according to the present invention shown in FIG. 3A and 3B show a state immediately after the trailing edge of the recording paper P has come out of the nip (clamping pressure) point between the transport driving roller 21 and the transport driven roller 22. FIG. ), The trailing edge of the recording paper P passes through the position of the line A connecting the shaft core of the transport driving roller 21 and the shaft core of the transport driven roller 22, and then is pinched by the transport driving roller 21 and the transport driven roller 22. It shows that the distance c is required until the state is completely removed.

  That is, the trailing edge of the recording paper P receives a force that causes it to be kicked downstream from the transport driving roller 21 and the transport driven roller 22 during the distance c. If such a “kicking phenomenon” occurs, if printing is being performed on the recording paper P, the printing result will be disturbed. That is, when the borderless printing is executed on the trailing edge of the recording paper P, the printing result is disturbed.

  On the other hand, FIG. 3B shows a state in which the conveying device 20 according to the present invention is completely in a state of being pinched by the conveying driving roller 21 and the conveying driven roller 22 after the trailing edge of the recording paper P has passed the position of the line A. 3, that is, the distance for receiving the force that the trailing edge of the recording paper P is kicked downstream is shorter than the distance c shown in FIG.

  Further, in FIG. 3, the conveyance driven roller indicated by a virtual line along with reference numeral 22 ′ indicates the position of the conveyance driven roller in a state where the recording paper P is pinched, and the conveyance driven roller indicated by a solid line along with reference numeral 22 indicates the recording paper P The position of the conveyance driven roller in a state where the pressure is not clamped is shown. As shown in the drawing, the displacement amount of the conveyance driven roller 22 when the trailing edge of the recording paper P is fed (approach amount to the conveyance drive roller 21) is The conveyance device 20 according to the present invention is extremely smaller than the conventional conveyance device 200.

  That is, as shown in FIGS. 4A to 4C, when the trailing edge of the recording paper P is pulled out between the transport driving roller 21 and the transport driven roller 22, the outer peripheral surface of the transport driven roller 22 is transported. Although it is close to the outer peripheral surface of the roller 21, in the conveying device 20 according to the present invention, since a gap is originally formed between both rollers by the flange portion 23, the outer peripheral surfaces of both rollers are in contact with each other. There is nothing to do.

Therefore, even when the thickness a of the recording paper P is large, the above-described kicking phenomenon when the trailing edge of the recording paper P comes out of the nip point between the transport driving roller 21 and the transport driven roller 22 does not cause a decrease in throughput. In addition, it can be effectively relaxed.
Further, when the leading edge of the recording paper P enters between the transport driving roller 21 and the transport driven roller 22 (the state shown in FIG. 4A), the transport driven roller 22 has already been transported by the presence of the flange portion 23. Therefore, the leading edge of the recording paper P can be easily inserted between the two rollers with a small load, and the load applied to the motor that drives the transport driving roller 21 can be reduced.

  Further, in the present embodiment, the gap b between the transport driving roller 21 and the transport driven roller 22 is formed directly by the flange portions 23 and 23, so the outer diameter of the flange portions 23 and 23 is managed. Thus, the gap b can be easily and precisely defined, and the gap b can be stably maintained over a long period of time. When the recording paper P is a dedicated paper having a coat layer and the thickness a is 0.26 mm, for example, it is desirable to manage the gap b from 0.13 mm to 0.20 mm.

  By the way, in this embodiment, although the flange parts 23 and 23 are integrally formed with the conveyance drive roller 21, it forms separately from the metal shaft body which comprises the conveyance drive roller 21, and the said metal shaft body is formed. It may be detachably provided at the shaft end. By doing so, the gap b can be easily adapted to the thickness a of the recording paper P to be conveyed by exchanging the flange portion.

  Furthermore, in the present embodiment, the transport driven roller 22 is urged toward the transport drive roller 21 at a position where the transport driven roller 22 is in pressure contact with the flange portions 23 and 23 (that is, in the vicinity of both shaft ends of the transport driven roller 22). It is possible to make the gap b uniform in the axial direction of the conveyance driven roller 21 without bending the conveyance driven roller 22, and to maintain the gap b stably over a long period of time. It has become.

  The embodiment of the present invention described above is an example, and it goes without saying that various modifications can be made without departing from the scope of the invention. For example, the transport driven roller 22 does not need to be a single shaft body long in the paper width direction as shown in FIG. 2, and a plurality of the transport driven rollers 22 may be provided in the axial direction of the transport drive roller 21. In this case, the gap b is not managed by providing flange portions at both shaft ends of the transport driving roller 21, but the position of the holder member that pivotally supports each transport driven roller 22 with respect to the transport driving roller 21 is regulated. It is desirable to use means.

1 is a schematic side sectional view of a printer according to the present invention. The perspective view of the conveying apparatus which concerns on this invention. (A) is the conveying apparatus which concerns on a prior art, (B) is sectional drawing of the conveying apparatus which concerns on this invention. FIG. 4 is an explanatory diagram showing a transition of a recording sheet conveyance state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet printer, 2 Feeding device, 10 Hopper, 11 Feeding roller, 12 Paper return lever, 13 Friction separation material, 14 Idle roller, 15 Lever, 16 Detection part, 17 Paper detector, 20 Recording medium conveyance apparatus, 21 Carrying Drive Roller 21 Carrying Driven Roller, 23 Flange, 25 Carriage, 26 Recording Head, 27 Carriage Guide Plate, 28 Platen, 29 Recording Medium Ejecting Device, 30 Ejecting Driving Roller, 31 Ejecting Driven Roller, 32 Ejecting Auxiliary Roller, 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 conveying driving roller;
In a state where the recording medium does not exist between the transport driving roller and the transport driven roller, a gap smaller than the thickness of the recording medium to be transported is formed between the transport driving roller and the transport driven roller. Yes,
A recording medium conveying apparatus characterized by the above. The conveyance drive roller according to claim 1, wherein a high friction layer is formed on an outer peripheral surface of a shaft body extending in a width direction of the recording medium, and a shaft end portion that is a non-formation portion of the high friction layer is formed on the shaft end portion. A flange portion having an outer diameter larger than the roller outer diameter in the formation portion of the high friction layer is provided,
The conveyance driven roller is formed by a shaft body extending in the width direction of the recording medium, and the shaft end portion is in pressure contact with the flange portion, thereby forming the gap.
A recording medium conveying apparatus characterized by the above. The flange portion according to claim 2, wherein the flange portion is integrally formed by cutting on the shaft body constituting the transport driving roller.
A recording medium conveying apparatus characterized by the above. The flange portion according to claim 2, wherein the flange portion is formed separately from the shaft body constituting the transport driving roller, and is detachably provided at a shaft end of the shaft body.
A recording medium conveying apparatus characterized by the above. In any one of Claims 2-4, the said conveyance follower roller is urged | biased toward the said conveyance drive roller in the position which press-contacts with the said flange part.
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 5.
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 ejection device configured to include a freely rotatable conveyance driven roller that sandwiches a medium to be ejected with the conveyance drive roller,
In a state where the ejected medium does not exist between the transport drive roller and the transport driven roller, a gap smaller than the thickness of the transported medium to be transported is formed between the transport drive roller and the transport driven roller. Yes,
A liquid ejecting apparatus.

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