JP2002348012A - Recording medium carrier, and recording device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the carrying accuracy of a recording medium, and to easily correct the skew in a carrier for carrying the continuous recording medium and a recording device thereof. SOLUTION: A recording medium carrying roll part comprising a driven roll shorter than the recording medium and a drive roll longer than the recording medium is provided on the downstream side of the paper sheet carrying direction of a recording medium skew correction unit, a recording medium guide part for removing wrinkles, etc., of the recording medium is provided in both directions on the upstream and downstream sides of the recording medium carrying roll part, and a recording medium puller part is provided on the downstream side of the recording medium guide part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport section and a skew correction section in a continuous recording medium transport apparatus, and to a recording apparatus therefor.

[0002]

2. Description of the Related Art In a continuous recording medium transporting apparatus, a configuration excluding a paper feeding section and a paper discharging section includes a transporting section for ensuring the transporting accuracy of the recording medium and a skew correcting section for correcting skew of the recording medium. It can be broadly divided. Paying attention to the transport unit and the skew correction unit, for example, when the recording medium is continuous paper with holes, a configuration is known in which a tractor is used in the transport unit of the recording medium to also perform skew correction.

In recent years, there has been known a device in which a tractor for performing skew correction and a roll for maintaining the conveyance accuracy are used in combination in order to increase the conveyance accuracy of the recording medium.

On the other hand, when the recording medium is continuous paper without holes,
There is known a configuration in which a roll is used for a transport section of a recording medium, and a skew correction section is capable of varying the roll pressure in the width direction of the recording medium.

[0005]

In a conventional apparatus for transporting a continuous recording medium, for example, when the recording medium is transported by a tractor only with continuous paper having holes, skew correction can be performed with a simple structure, but the tractor pin and the recording medium are conveyed. There is a problem in that the feeding accuracy of the recording medium is reduced due to the gear feeding with the pin holes of the medium.

Further, in the case of a configuration in which the skew is corrected by the tractor and the transport accuracy is increased by the rolls, it is necessary to increase the pressing force between the two rolls in order to eliminate the slip of the recording medium with respect to the rolls. As a result, there is a drawback that variations in the outer diameter accuracy of the two rolls, the pressing force of the rolls, or the variations in the roll mounting accuracy appear remarkably in the skew of the recording medium, and the recording medium comes off the tractor. In this case, it is necessary to appropriately reduce the pressing force between the two rolls to suppress the skew generated between the two rolls, in other words, to cause the recording medium to slide on the rolls to some extent. However, there is a limit in improving the accuracy of conveying the recording medium.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a recording-medium conveying apparatus which has high accuracy in conveying a recording medium and can easily correct skew, and a recording apparatus therefor.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a recording medium transport apparatus for performing recording from a recording unit to a recording medium includes a recording medium holding unit facing the recording unit, A first recording medium guide located upstream of the recording medium holding unit in the recording medium transport direction; a recording medium transport roll located upstream of the first recording medium guide in the recording medium transport direction; A second recording medium guide located upstream of the medium transport roll in the recording medium transport direction, a recording medium skew correction located upstream of the second recording medium guide in the recording medium transport direction; A transport comprising a third recording medium guide located downstream of the medium holding unit in the recording medium transport direction, and a recording medium puller located downstream of the third recording medium guide in the recording medium transport direction. Equipment The recording medium transport roll section is a drive roll on the back side of the recording surface of the recording medium that is longer than the maximum width of the recording medium, and is shorter than the minimum width of the recording medium on the recording surface side of the recording medium. A driven roll having means movable in a direction is provided.

Further, in the recording medium transporting device, the recording medium transporting roll portion uses a metal as a driving roll material and an elastic member as a driven roll material.

Further, in the recording medium transport apparatus, the recording medium skew correction unit is a tractor having means for switching between driving and driven, and means for varying the rotational load force when driven, and the recording medium puller is a driving tractor. The tractor of the recording medium skew correction unit is driven in the recording medium transport direction during printing, and is driven when the direction is opposite to the recording medium transport direction during printing.

In the recording medium transport device, a rotary encoder is provided on one of the rotation shafts of the recording medium skew correction unit and the tractor of the recording medium puller unit. There is a control unit for correcting the transport amount of the recording medium transport roll unit from the value.

Further, the driven roll of the recording medium transport roll section has means for linking the movement in the recording medium width direction with the tractor of the recording medium skew correction section.

The recording medium skew correction unit is a driven roll on one side and a driven roll having means capable of changing the pressure in the width direction of the recording medium on the other side.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

In the following embodiments, continuous paper with holes in the form of roll paper is used as a recording medium, but the form, type, material, etc. may be any.

FIG. 1 is a side view showing a recording medium transport device and an example of the recording device according to an embodiment of the present invention, and FIG. 2 is a front view showing the vicinity of a recording medium transport roll seen from the direction of arrow B in FIG. FIG.

Reference numeral 1 denotes a recording means comprising an ink jet recording head, which has a plurality of nozzles for ejecting ink (not shown), and discharges ink downward in accordance with a recording signal to record on a recording medium shown below. I can do it.

Reference numeral 2 denotes a recording medium made of continuous paper having a recording surface 2a and is conveyed in the direction of arrow A during recording. A paper feed unit 2b is arranged on the most upstream side of the recording medium 2 in the recording medium transport direction, and a paper discharge unit 2c is arranged on the most downstream side, and has a driving unit (not shown).

Reference numeral 3 denotes a recording medium holding unit facing the recording means 1. A fixed plate is formed by curving the recording surface 2a of the recording medium 2 in a convex direction along the arrow A direction during recording conveyance.

Reference numeral 4 denotes a first plate which is located on the upstream side of the recording medium holding section 3 in the recording medium transport direction and is formed of a fixed plate having the recording surface 2a of the recording medium 2 curved in the convex direction along the direction of arrow A.
Is a recording medium guide section.

Reference numeral 5 denotes a recording medium transport roll located upstream of the first recording medium guide 4 in the recording medium transport direction. A drive roll 5b driven by a motor 5a is provided on the back side of the recording surface 2a of the recording medium 2. On the recording surface 2a side, there is provided a driven roll 5c for pressing the recording medium 2 against the driving roll 5b by an urging member (not shown). Here, the drive roll 5b is longer than the maximum width of the recording medium 2,
The driven roll 5c is set shorter than the minimum width of the recording medium 2. Further, the driven roll 5c is movable in the direction of arrow C which is the width direction of the recording medium 2. The material of the driving roll 5b is a metal made of stainless steel,
The surface is roughened by shot peening or the like so that sliding with the recording medium 2 hardly occurs. The material of the driven roll 5c is preferably an elastic member such as polyurethane rubber.

Reference numeral 6 denotes a second recording medium guide, which is a fixed plate that is located on the upstream side of the recording medium transport roll 5 in the recording medium transport direction and is curved in the same direction as the first recording medium guide 4.

Reference numeral 7 denotes a recording medium skew correction unit located upstream of the second recording medium guide unit 6 in the recording medium transport direction.
A tractor 7a having means (not shown) for switching between driving and driven, and means for varying the rotational load force when driven
It is composed of Reference numeral 7b denotes a rotary encoder fixed to a rotating shaft 7c of the tractor 7a.
A pulse value corresponding to the rotation amount of a is generated. Reference numeral 7d denotes a driving roll 5 based on the pulse value of the rotary encoder 7b.
This is a control unit that corrects the amount of rotation of the motor 5a that drives b.

Reference numeral 8 denotes a third recording medium guide section which is located on the downstream side of the recording medium holding section 3 in the recording medium transport direction and is composed of a fixed plate curved in the same direction as the first recording medium guide section 4.

Reference numeral 9 denotes a recording medium puller located downstream of the third recording medium guide 8 in the recording medium transport direction, and is constituted by a tractor 9a which is rotated by driving means (not shown).

Next, the operation of transporting the recording medium 2 will be described.

In this transport device, the transport speed or transport accuracy is determined by the recording medium transport roll unit 5.
Of the driving roll 5b. Here, the transport speed of the tractor 9a of the recording medium puller unit 9 located downstream of the recording medium transport roll unit 5 in the recording medium transport direction causes a slack in the recording medium 2 between the recording medium transport roll unit 5 and the tractor 9a. The speed is set slightly higher than the transport speed of the drive roll 5b so as not to cause any problem. For this reason, although not shown, the drive unit of the tractor 9a has slip means. Here, the conveyance force when the tractor 9a slips is smaller than the clamping force of the recording medium 2 between the driving roll 5b and the driven roll 5c, and is a value necessary and sufficient to convey the recording medium 2. Needless to say.

On the other hand, the tractor 7a of the recording medium skew correction unit 7 has a means (not shown) for switching between driving and driven, but functions as driven when the recording medium 2 is being conveyed in the direction of arrow A during recording conveyance. This is because when both the driving roll 5b and the tractor 7a are driven, the tractor 7
This is because the transfer unevenness a adversely affects the transfer accuracy of the drive roll 5b. In addition, when the tractor 7a is driven, the tractor 7a has means for varying a rotational load force (not shown).
It is possible to change the rotational load force of the tractor 7a, that is, the back tension of the recording medium 2 by the difference in the continuous paper amount of the recording medium 2 or the like. For example, when the continuous paper amount is large, the rotational load of the tractor 7a is preferably large, and when the continuous paper amount is small, the rotational load of the tractor 7a is preferably small.

In this case, it is possible to prevent the accuracy from being deteriorated due to the interference of the conveyance deviation generated between the driving tractor and the driving roll. Further, the recording medium can be easily conveyed in the direction opposite to the recording medium conveyance direction during recording.

Further, the drive roller 5b is corrected and controlled via the control unit 7d by the pulse value of the rotary encoder 7b attached to the rotating shaft of the tractor 7a, so that the recording medium 2 having perforations between pages can be obtained. It is possible to correct the accumulated deviation of the recording head position. There is no problem whether the timing of correcting the accumulated deviation of the recording head position is every page or every specific page. In this case, it is possible to prevent the accumulation of the recording head position deviation between the pages of the recording medium due to the variation of the roll outer diameter accuracy.

Next, a description will be given of a conveying operation when the recording medium 2 is conveyed in the direction opposite to the direction of arrow A when the recording medium is conveyed. This reverse rotation operation is performed, for example, when the recording medium 2 conveyed extra after the ink discharge of the recording unit 1 is stopped is returned to a specified value and then reprinted. As a result, the recording medium 2 can be saved. In this case, the tractor 7a is switched from driven to driven, and the other tractor 9a, the driving roll 5b, and the sheet feeding unit 2b
And the reverse rotation operation of the paper discharge unit 2c.

A description will now be given of the conveyance accuracy and the skew correction when the recording medium 2 is conveyed by the driving roll 5b during recording.

As described above, in order to improve the conveyance accuracy of the recording medium 2 on the driving roll 5b, in addition to improving the outer shape accuracy and the mounting accuracy of the driving roll 5b itself, the pressing force of the driven roll 5c against the driving roll 5b is reduced. It is necessary to make the recording medium 2 slippery with respect to the driving roll 5b. Here, since the driven roll 5c is set shorter than the minimum width of the recording medium 2, the skew of the recording medium 2 on the driving roll 5b can be reduced even if the pressing force of the driven roll 5c is large. . this is,
Because the length of the driven roll 5c is short, the influence of variations in the roll pressing force in the width direction of the recording medium 2 and variations in the mounting accuracy of the driven roll 5c and the driving roll 5b, which cause skew, are reduced. The width of the driven roll 5c is between 0.1 and 0.6 when the width of the recording medium is 1, and the position of the driven roll 5c is set at the center position in the width direction of the recording medium 2. Is preferred. Further, since the driven roll 5c is movable in the direction indicated by C in FIG. 2, even if the width size of the recording medium changes, the driven roll position can be set to an appropriate position.

On the other hand, since the length of the driven roll 5c is short, the recording medium 2 at a position deviated from both ends of the driven roll 5c may be distorted. There is no problem because the wrinkles are stretched by the first recording medium guide section 4 and the second recording medium guide section 6 provided on the upstream side and the downstream side in the direction.
More specifically, in the case of the present example, the distortion of the sheet is likely to occur on the portion where there is no roll, that is, on the driven roll side. Therefore, in the first recording medium guide section 4 and the second recording medium guide section 6, the guide is curved so that the printing surface is convex, so that the centripetal force due to the paper tension is directed to the drive roll side. As a result, the distortion of the sheet can be prevented, and the conveyance of the sheet can be stabilized.

When the drive roll 5b is made of metal, it is possible to improve the external processing accuracy of the drive roll, to maintain the dimensional stability over time, and to stably transport the recording medium regardless of the apparatus environment.

In the present invention, as described above, it is possible to prevent the paper skew around the short driven roll while firmly nipping the paper with the short driven roll. In addition, by curving the recording medium guide in the direction in which the printing surface becomes convex, wrinkles are prevented together, so that excessive force due to paper tension is prevented from being applied to the short driven roll side urged by the spring. I can do it.

In this embodiment, the recording medium holding unit is a fixed plate. However, an endless belt drive having a recording medium suction means or a plurality of driven rolls may be used. First,
The second and third recording medium guides may also be driven rollers instead of fixed plates. In this case, the sliding of the recording medium with the recording medium holding section and the first, second, and third recording medium bending sections is eliminated, so that the generation of paper dust can be reduced.

In this embodiment, the recording medium skew correction unit is a tractor. However, one may be a drive roll and the other may be a driven roll having a unit capable of varying the pressure in the width direction of the recording medium. In this case, skew correction can be performed even for continuous paper having no holes in the recording medium.

[0039]

As described above, according to the present invention,
On the downstream side of the recording medium skew correction unit in the sheet transport direction, by providing a driven roll shorter than the recording medium and a recording medium transport roll unit including a drive roll longer than the recording medium,
Even if the pressing force of the driven roll is increased, the skew of the paper on the drive roll can be reduced.

Further, in the present invention, a recording medium guide portion for removing wrinkles or the like of a recording medium is provided in both directions upstream and downstream of the recording medium transport roll portion, and the guide portion is formed so that the printing surface side of the paper is convex. By bending, it is possible to prevent the paper from being distorted due to the short length of the driven roll, and to prevent an extra force from being applied to the driven roll.

Further, since the driven roll can be moved in the width direction of the recording medium, the driven roll can be moved to an appropriate position even if the width size of the recording medium changes.

Further, since the material of the driving roll is made of metal and the material of the driven roll is made of an elastic member, it is possible to improve the external processing accuracy of the driving roll, to maintain the dimensional stability over time, and to stably transport the recording medium regardless of the apparatus environment. I can do it.

Further, since the recording medium skew correction unit is provided with a unit for switching between driving and driven and a unit capable of varying the rotational load force during driven, the recording medium skew correction unit is caused by interference of a conveyance deviation generated between the driving tractor and the driving roll. Accuracy deterioration can be eliminated, and the recording medium can be easily transported in the direction opposite to the recording medium transport direction during recording.

Also, a rotary encoder is provided on one of the rotating shafts of the recording medium skew correction unit and the tractor of the recording medium puller unit. By providing the control means for correcting the transport amount, it is possible to prevent the accumulation of the recording head position deviation between the pages of the recording medium due to the variation of the roll outer diameter accuracy.

Further, the recording medium skew correction section is constituted by a driving roll on one side and a driven roll having means capable of varying the pressure in the width direction of the recording medium, so that the skew can be maintained even when the recording medium is continuous paper without holes. Correction is possible.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a recording medium transport device according to an example of the invention.

FIG. 2 is a front view showing the vicinity of a recording medium transport roll section viewed from the direction of arrow B in FIG. 1;

[Explanation of symbols]

1 is a recording means, 2 is a recording medium, 2a is a recording surface, 2b is a paper feeding section, 2c is a paper discharging section, 3 is a recording medium holding section, 4 is a first recording medium guide section, and 5 is a recording medium transport roll. 5a, a motor, 5b a drive roll, 5c a driven roll, 6 a second recording medium guide unit, 7 a recording medium skew correction unit,
7a is a tractor, 7b is a rotary encoder, 7c is a rotating shaft, 7d is a control unit, 8 is a third recording medium guide unit, 9
Denotes a recording medium puller, and 9a denotes a tractor.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65H 20/02 B65H 20/02 Z 20/20 20/20 B 23/14 23/14 (72) Inventor Hiroshi Ikeda 1060 Takeda, Hitachinaka-city, Ibaraki Pref. Hitachi Koki Co., Ltd. (72) Inventor Michiaki Wataniki 1060 Takeda, Hitachinaka-shi, Ibaraki Pref. F-term in Hitachi Koki Co., Ltd. AF35 EA02 EA09 EA17 GA02 GB07 GB20 GB43 GB47 2C060 BA01 BC03 BC12 BC15 BC41 BC46 BC85 3F103 AA02 BA01 BA33 BA35 BE03 3F104 AA02 CA11 JA10 JC06 JC08 KA12

Claims (8)

[Claims] A recording medium holding section facing the recording means; a first recording medium guide section located upstream of the recording medium holding section in a recording medium conveying direction; and recording of the first recording medium guide section. A recording medium transport roll positioned upstream in the medium transport direction, a second recording medium guide positioned upstream of the recording medium transport roll in the recording medium transport direction, and recording of the second recording medium guide A recording medium skew correction unit located on the upstream side in the medium transport direction, a third recording medium guide unit located on the downstream side in the recording medium transport direction of the recording medium holding unit,
A recording medium transport device for performing recording on a recording medium from recording means, comprising: a recording medium puller located downstream of the third recording medium guide in the recording medium transport direction; Is a drive roll that is longer than the maximum width of the recording medium provided on the back side of the recording medium, and is shorter than the minimum width of the recording medium provided on the recording surface side of the recording medium, and moves in the width direction of the recording medium. A recording medium transport device, characterized in that the device is a possible driven roll. 2. The recording medium conveying apparatus according to claim 1, wherein in the recording medium conveying roll section, a material of a driving roll is made of metal and a material of a driven roll is an elastic member. 3. The recording medium puller section is a drive tractor, and the recording medium skew correction section is a tractor having means for switching between driving and driven, and having means capable of varying a rotational load force during driven. 3. The conveyance of a recording medium according to claim 1, wherein the tractor of the recording medium skew correction section is driven in the recording medium conveyance direction, and is driven in the direction opposite to the recording medium conveyance direction during recording. apparatus. 4. A rotary encoder is provided on one of the rotating shafts of the recording medium skew correction unit and the tractor of the recording medium puller unit, and at the time of inter-page feed at the time of recording, the recording medium is calculated from a pulse value of the rotary encoder. 4. The apparatus according to claim 3, further comprising control means for correcting the transport amount of the transport roll. 5. A recording apparatus according to claim 3, wherein said driven roll of said recording medium transport roll section has means for interlocking movement in the recording medium width direction with a tractor of said recording medium skew correction section. Media transport device. 6. The recording apparatus according to claim 1, wherein one of the recording medium skew correction units is a driven roll, and the other is a driven roll having a unit capable of varying pressure in the width direction of the recording medium. Media transport device. 7. A recording apparatus comprising the recording medium transport device according to claim 1. 8. A recording apparatus according to claim 7, wherein said recording means has an ink jet recording head which performs recording by discharging ink.