JP2008254219A - RECORDED MEDIUM CONVEYING DEVICE, RECORDING DEVICE HAVING THE SAME, AND LIQUID EJECTING DEVICE - Google Patents

Abstract

When a leading edge of a recording medium reaches a discharge driving roller, it is possible to suppress the occurrence of skew of the recording medium, and to reduce the possibility of a boundary being formed in a recorded image or distortion in recording. To provide a recording medium conveying apparatus capable of performing the above.
A recording roller that defines a conveyance path of the recording medium so as to be symmetrically positioned with respect to a center line in the width direction of the recording medium, and a discharging roller having a plurality of discharging driving rollers and a discharging driven roller. Load applying means is provided at a position that coincides with the center line in the width direction of the recording medium that is conveyed upstream of the discharge roller.
[Selection] Figure 2

Description

  The present invention relates to a recording medium conveying apparatus configured to convey a recording material with reference to a center position in the width direction, and a recording apparatus including the recording medium conveying apparatus. Furthermore, the present invention relates to a liquid ejecting apparatus such as an ink jet recording apparatus that performs recording (attaches liquid) on a recording medium (liquid ejecting medium) by ejecting (ejecting) a liquid such as ink from the head, and the like. The present invention relates to a liquid ejecting medium conveying apparatus provided for 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 records ink on a recording medium by discharging ink from the recording head. It includes a device that ejects a liquid corresponding to the application from a liquid ejecting head corresponding to the 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.

  When the recording medium is conveyed from the feeding device to the recording medium feeding roller and the discharge roller side, the recording medium conveying device configured to convey the recording material based on the center position in the width direction is as follows. It is configured as follows. In other words, the conveyance path of the recording medium is defined by the pair of side guides so that the plurality of ejection driving rollers and the ejection driven roller constituting the ejection roller are positioned symmetrically with respect to the center line in the width direction of the recording medium. In addition, both axes of the discharge roller and the recording medium feed roller are provided in parallel.

  Here, if the discharge roller and the recording medium feed roller are provided completely in parallel, the recording medium theoretically advances straight without skewing, and the front end of the recording medium is almost simultaneously over the entire length. It reaches the discharge roller, is nipped and is conveyed straight as it is. Therefore, it can be said that there is no deterioration in recording quality due to skew.

Conventionally, the nozzle density of the recording head is relatively low for manufacturing reasons, and the interval between the nozzles is relatively long, so that the recording medium is recorded in order to eliminate the blank portion of the recording due to the presence of the interval between the nozzles For example, four scanning operations, that is, four-pass operations, are performed on the same region (raster) while being gradually shifted with respect to the head in the sub-scanning direction that is the transport direction. Such conventional techniques are disclosed in, for example, Patent Document 1 and Patent Document 2.
JP 9-169109 A JP 2002-103580 A

The problem of the present invention will be described based on FIG.
It is practically difficult to make the discharge roller 100 and the recording medium feed roller in a completely parallel state due to a manufacturing error or the like. Therefore, in actuality, the discharge roller 100 and the recording medium feed roller are extremely small. However, since the recording medium P is transported, either the left or right of the front end of the recording medium P reaches the discharge driving roller 100 first. As a result, the front end portion of the recording medium P that has reached the discharge drive roller 100 first receives a load that is not received by the free front end portion that has not reached the recording medium P. The feed tends to be delayed, while the forward end portion of the free state on the side that reaches the discharge drive roller 100 with a delay tends to advance.

  That is, in FIG. 7, a load as indicated by an arrow F is applied at the front left end of the recording medium P that reaches the discharge driving roller 100 first, and a moment indicated by an arrow A is applied at the center of the recording medium P. At the right end of the recording medium P in the traveling direction, a moment indicated by an arrow B acts. As a result, a rotational force indicated by an arrow R is generated in the recording medium P, which causes the recording medium P to skew or bend. As a result, the position of the recording medium immediately below the recording head slightly shifts, so that a boundary on the image is formed between the recording image executed on the recording medium before the shift and the recording image after the shift. There is a possibility that the recording may be distorted.

  Further, due to recent technological advances, the nozzle density in the recording head has increased, and the need for a 4-pass operation has been eliminated, and the development of a recording apparatus in the direction of recording in a 2-pass or 1-pass operation has been studied to improve throughput. ing. When the 2-pass or 1-pass operation is realized, the recording distortion and the boundary on the image due to the above-mentioned reason become more conspicuous than the case of the 4-pass operation, which causes the recording quality to deteriorate.

  The present invention has been made in view of the above circumstances, and a recording medium transport apparatus capable of suppressing the occurrence of skew of the recording medium when the front end of the recording medium reaches the discharge driving roller. It is another object of the present invention to provide a recording apparatus and a liquid ejecting apparatus including the same.

  In order to achieve the above object, a recording medium transporting apparatus according to a first aspect of the present invention is symmetrical with respect to a discharging roller having a plurality of discharging driving rollers and discharging driven rollers, and a center line in the width direction of the recording medium. And a recording medium side guide means for defining a conveyance path of the recording medium so as to be positioned at the same position, which is upstream of the discharge roller and coincides with the center line in the width direction of the recording medium to be conveyed Is provided with load applying means.

According to the first aspect of the present invention, the center of the front end of the recording medium first reaches the load applying unit, and then the recording medium receives either the left or right of the recording medium while receiving the load from the load applying unit. The front end reaches the discharge drive roller. At this time, since the load applying means is already in contact with the center of the recording medium, the grip force acts on that portion, and the feed on the side that has reached before the discharge driving roller tends to be delayed, while it reaches later. Problems that tend to advance the feeding on the side to be performed are suppressed.
Therefore, when the leading edge of the recording medium reaches the discharge driving roller, the occurrence of skew of the recording medium can be suppressed, and the possibility that a boundary is formed in the recorded image or the recording is distorted is reduced. be able to.

  According to a second aspect of the present invention, there is provided the recording medium transport device according to the first aspect, wherein the load applying means is provided with a follow-up rotatable load applying tooth provided above the transport path of the recording medium. It is a roller, and the lower end side of the roller with load applying teeth is arranged so as to cross a part of the conveyance path of the recording medium.

  According to this aspect, after the center of the front end of the recording medium reaches the load applying toothed roller, the recording medium passes under the load applying toothed roller. When either the left or right front end of the recording medium reaches the ejection drive roller, the load-applying toothed roller contacts the surface of the recording medium and the blade edge is slightly stuck, so that the grip force of the recording medium is ensured. And skew of the recording medium can be suppressed. Since the cutting edge is very small, even if it is pierced as described above, the recorded image is not affected.

  Further, in the recording medium transport apparatus according to a third aspect of the present invention, in the first aspect, the load applying means is a load applying rib provided below a transport path of the recording medium, The top part of the load applying rib is arranged so as to cross a part of the conveyance path of the recording medium.

  According to this aspect, after the center of the front end of the recording medium collides with the load applying rib, the recording medium passes through the upper side in a contact state supported from below on the top of the load applying rib. When either the left or right front end of the recording medium reaches the discharge drive roller, the load applying rib is in frictional contact with the lower surface of the recording medium, so that the grip force of the recording medium is reliably generated, and the recording medium Skew can be suppressed.

According to a fourth aspect of the present invention, there is provided the recording medium transport apparatus according to any one of the first to third aspects, wherein the guide for guiding the recording medium to the load applying unit is the load applying apparatus. It is provided in the upstream of this.
According to this aspect, it is possible to guide the front end of the recording medium so as to reliably reach the position of the load applying unit.

A recording apparatus according to a fifth aspect of the present invention is a recording apparatus including a recording medium transport device and a recording execution unit that executes recording on the recording medium transported by the recording medium transport device. In addition, the recording medium conveyance device is a recording medium conveyance device according to any one of the first to fourth aspects.
According to this aspect, since the skew of the recording medium can be suppressed, even when recording is performed by two-pass or one-pass operation, it is possible to prevent recording quality deterioration such as recording distortion and image boundary. Can do.

  The liquid ejecting apparatus according to the sixth aspect of the present invention includes a liquid ejecting medium transport device, and a liquid ejecting execution unit that performs liquid ejecting on the liquid ejecting medium transported by the liquid ejecting medium transport device. The liquid ejecting medium conveying apparatus includes a discharge roller including a plurality of discharge driving rollers and a discharge driven roller, and a symmetrical position with respect to a center line in the width direction of the liquid ejecting medium. And a liquid jet medium side guide means that defines a transport path of the liquid jet medium, and a position that is upstream of the discharge roller and coincides with the center line in the width direction of the liquid jet medium to be transported Is provided with load applying means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a side sectional view of an ink jet printer to which a recording medium conveying apparatus according to an embodiment of the present invention is applied. FIG. 2 is a plan view showing the periphery of the recording medium conveying apparatus. FIG. 4 is a side sectional view showing the apparatus, and FIG. 4 is a schematic view for explaining the operation of the present invention.

  An ink jet recording apparatus 1 shown in FIG. 1 (hereinafter simply referred to as a recording apparatus) includes a feeding device 5 behind the recording apparatus main body 3. The feeding device 5 includes recording medium side guide means 6 having a pair of left and right side guides that can move by the same distance in the width direction according to the width dimension of the recording medium P. Therefore, when both sides of the recording medium P are guided between the pair of side guides of the side guide means 6, the width of the recording medium P in the width direction is increased regardless of the size of the recording medium P. The position of the center line L is the same.

  The recording medium P loaded on the feeding device 5 is pressed against the outer peripheral surface of the feeding roller 7 by a hopper 9 that swings toward the feeding roller 7, and the recording medium is driven by the driving rotation of the feeding roller 7. A sheet is automatically fed one by one toward a recording medium feed roller 12 composed of a roller 10 and a recording medium driven roller 11. The recording medium feed roller 12 has a function of conveying the recording medium P onto the platen 17 at an accurate pitch.

  The recording apparatus main body 3 includes a carriage 15 for reciprocally moving a recording head 13 that performs recording by ejecting ink onto the recording medium P with respect to the recording medium P in the width direction (main scanning direction). Yes. A plurality of ink cartridges filled with ink of each color are detachably mounted on the carriage 15, and ink of each color is supplied from the ink cartridge to the recording head 13. The recording head 13 reciprocates in the width direction at a position facing the platen 17. A large number of nozzles are arranged on the head surface of the recording head 13.

The recording medium P on which recording has been performed by the recording head is discharged by the discharge roller 25. The discharge roller 25 includes a plurality of discharge drive rollers 26 and a plurality of discharge driven toothed rollers 27 corresponding to the discharge driven rollers. The discharge roller 25 and the recording medium feed roller 12 are provided so as to be “substantially parallel” by design, but they are not completely parallel due to manufacturing errors and the like.
Here, “substantially parallel” means that the discharge roller 25 and the recording medium feed roller 12 are designed and manufactured so as to be completely parallel, but manufacturing errors, etc. For reasons, it means a state that is virtually not parallel.

  As shown in FIG. 2, the plurality of discharge driving rollers 26 and the rollers 27 with discharge driven teeth are the centers in the width direction of the recording medium P when the recording medium P is conveyed from the upstream side to the discharge roller 25 side. They are arranged so as to have a symmetrical positional relationship with respect to the line L. Thereby, the skew of the recording medium P caused by the difference in driving force received from the discharge driving roller 26 acting on the left and right sides of the center line L is prevented. For example, in the postcard size recording medium P, as shown in FIG. 2, two discharge driving rollers 26 and two rollers 27 with discharge driven teeth are arranged symmetrically on both sides of the center line L.

  As shown in FIG. 3, on the upstream side of the discharge driven toothed roller 27, a roller 29 with presser teeth that suppresses lifting of the front and rear ends of the recording medium can be driven and rotated at an appropriate interval in the width direction. Is provided. In the present invention, it is not always necessary to provide the pressing roller 29 with the pressing teeth. In FIG. 2, the roller 29 with the presser teeth is not provided.

  Next, a characteristic configuration of the present invention will be described. In FIG. 2, on the upstream side slightly below the discharge driven toothed roller 27, and in FIG. 3 on the upstream side slightly below the pressing toothed roller 29, at a position above the transport path of the recording medium P. A roller 31 with load applying teeth corresponding to the load applying means is provided. The lower end side of the load applying toothed roller 31 is disposed so as to cross a part of the conveyance path of the recording medium P so that the front end of the recording medium P contacts. Furthermore, the roller 31 with load imparting teeth is arranged so as to overlap the center line L in the width direction of the recording medium P being conveyed or an extension line thereof.

  Therefore, when the recording medium P is conveyed to the discharge roller 25 side, the center of the front end of the recording medium P first reaches the contact roller 31 with load application teeth and comes into contact therewith. At this time, since the contact position of the recording medium P with the load applying toothed roller 31 is the center of the front end, the front end of the recording medium P reaches the load applying toothed roller 31 as shown by a broken line in FIG. Thus, the recording medium P does not skew at the time of contact.

  Next, the operation will be described. After the recording medium P reaches and comes into contact with the load-applying toothed roller 31, the recording medium P passes under the load-applying toothed roller 31, and as shown by a solid line in FIG. Either the left or right front end reaches the discharge drive roller 26. However, at this time, since the roller 31 with load imparting teeth is already in contact with the center of the recording medium P, a grip force acts at the contact portion, and the side that reaches the discharge driving roller 26 first (in FIG. 4). The feeding of the recording medium P on the left side in the advancing direction tends to be delayed, and the problem that the feeding on the side that reaches later tends to advance is suppressed.

  That is, in FIG. 4, a load as indicated by an arrow F is applied to the recording medium P at the front end of the recording medium P that reaches the discharge driving roller 26 first, and a moment indicated by an arrow A is present at the center of the recording medium P. In addition, a moment indicated by an arrow B acts on the right end of the recording medium P. However, the roller 31 with load imparting teeth is in contact with the center of the recording medium P, and grip force (arrow C) acts at the contact portion, so that at least a part of the moment acting on the recording medium P is at least a part. The force for rotating the recording medium P is reduced by canceling the grip force. Therefore, when the front end of the recording medium P reaches the discharge driving roller 26, the occurrence of skew of the recording medium P is suppressed, and the possibility that a boundary is formed in the recorded image or the recording is distorted is also reduced. The

  Based on FIG. 5, another embodiment of the present invention will be described. In the present embodiment, as shown in FIG. 5, a load applying rib 33 is provided instead of the load applying toothed roller 31. The load applying rib 33 is also located on the center line L in the width direction of the recording medium P being conveyed or its extension line, as in the case of the roller 31 with load applying teeth described above. The load applying rib 33 is provided below the conveyance path of the recording medium P, and is disposed so as to cross a part of the conveyance path of the recording medium P. The central lower surface comes into contact with the top of the load applying rib 33. The action of the load applying rib 33 is the same as that of the roller 31 with the load applying tooth, and the center of the front end of the recording medium P is first brought into contact with the load applying rib 33 so that the load applying rib 33 and the recording medium are recorded. The frictional force of contact with the lower surface of the medium P acts as a grip force, and the problem that the feed on the side that reaches the discharge drive roller 26 tends to be delayed and the feed on the side that reaches later tends to advance is suppressed. .

  Still another embodiment of the present invention will be described with reference to FIG. In this embodiment, a guide 35 for guiding the front end of the recording medium P is provided immediately upstream of the load applying toothed roller 31 in the embodiment provided with the load applying toothed roller 31 described above. By providing the guide 35, the front end of the recording medium P can be surely reached near the lower end of the roller 31 with load application teeth.

  As described above, the embodiment in which the present invention is applied to the ink jet recording apparatus has been described. However, the present invention can be applied to a liquid ejecting apparatus instead of the recording apparatus. That is, in the liquid ejecting apparatus that transports the liquid ejecting medium in a state where the position of the center line in the width direction of the liquid ejecting medium is defined, and ejects the liquid from the liquid ejecting head to the liquid ejecting medium in the same manner as described above. The present invention can be applied.

1 is a side sectional view of an ink jet printer to which the present invention is applied. FIG. 4 is a plan view showing the periphery of the discharge roller from the recording medium feeding roller according to the embodiment of the present invention. FIG. 3 is a side cross-sectional view showing the periphery of a discharge roller from the recording medium feeding roller. The schematic diagram explaining the effect | action of the roller with the same load provision tooth | gear. The sectional side view which concerns on other embodiment of this invention, and is provided with a load provision rib. The sectional side view which shows embodiment with guide concerning other embodiment of this invention. Explanatory drawing which shows the conventional problem.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus, 3 recording apparatus main body, 5 feeding apparatus, 6 recording medium side guide apparatus, 7 feeding roller, 9 hopper, 10 recording medium drive roller, 11 recording medium driven roller, 12 recording medium Feed roller, 13 Recording head, 15 Carriage, 17 Platen, 25 Discharge roller, 26 Discharge drive roller, 27 Discharge driven toothed roller, 29 Presser toothed roller, 31 Load imparting toothed roller, 33 Load imparting rib, 35 Guide, P Recording medium, L Center line in the width direction of the recording medium

Claims (6)

A discharge roller comprising a plurality of discharge drive rollers and a discharge driven roller;
Recording medium side guide means for defining a conveyance path of the recording medium so as to be positioned symmetrically with respect to the center line in the width direction of the recording medium;
A recording medium conveying apparatus, wherein a load applying means is provided at a position that is upstream of the discharge roller and coincides with a center line in the width direction of the recording medium to be conveyed.   2. The recording medium conveying apparatus according to claim 1, wherein the load applying means is a follower-rotating load applying toothed roller provided on an upper side of the recording medium conveying path, and a lower end of the load applying toothed roller. The recording medium transporting apparatus is characterized in that the side is disposed so as to cross a part of the transport path of the recording medium.   2. The recording medium conveying apparatus according to claim 1, wherein the load applying means is a load applying rib provided on a lower side of the recording medium conveying path, and a top portion of the load applying rib is a conveying path of the recording medium. A recording medium transporting apparatus, wherein the recording medium transporting apparatus is disposed so as to cross a part of the recording medium.   4. The recording medium transport apparatus according to claim 1, wherein a guide for guiding the recording medium to the load applying unit is provided on an upstream side of the load applying apparatus. Recording medium transporting apparatus. A recording medium transport device;
A recording execution unit that performs recording on a recording medium conveyed by the recording medium conveyance apparatus,
The recording apparatus according to claim 1, wherein the recording medium conveyance apparatus is a recording medium conveyance apparatus according to claim 1. A liquid ejecting medium conveying device;
A liquid ejection execution unit that performs liquid ejection on a liquid ejection medium transported by the liquid ejection medium transport apparatus,
The liquid ejecting medium conveying device is
A discharge roller comprising a plurality of discharge drive rollers and a discharge driven roller;
Liquid target medium side guide means for defining a transport path of the liquid target medium so as to be positioned symmetrically with respect to the center line in the width direction of the target liquid medium;
A liquid ejecting apparatus, wherein a load applying unit is provided at a position that is upstream of the discharge roller and coincides with a center line in a width direction of the liquid ejecting medium to be conveyed.

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