JPH10129056A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical ink jet recorder wherein contact of a record head with a recording medium at the discharging is prevented and a printed region with good image quality is expanded. SOLUTION: This recorder comprises a conveying means 10 that conveys a printing medium P from an upstream portion to a printing region, a first discharge device 30 that discharges the printing medium P from the printing region to a downstream portion and of which conveying force for the printing medium P is set lower than that of the conveying means and a second discharge device 40 that is provided to a downstream side of the first discharge device. The discharge devices are comprised of driving rotary bodies 31, 41 that support the printing medium P at a side opposite a printing face and rotary bodies 33, 43 which are provided in opposition to the driving rotary bodies 31, 41 and rotate by contacting the printing face of the printing medium P. Each of a tolerance in diameter and a tolerance in vibration of the driving rotary body 31 of a first conveyance device is smaller than that of the driving rotary body 41 of a second conveyance device, respectively, then a conveyance force of the printing medium at the first discharge device 30 is greater than that of the second discharge device 40 so that the conveying accuracy of the printing medium P which is just after the discharging from the device is enhanced and a printing region having a good quality image is expanded to a rear edge of the printing medium P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus having a mechanism for discharging a recorded recording medium, and more particularly to an enlargement of a print area of a recording medium and a simplification of a transport mechanism.

[0002]

2. Description of the Related Art An ink jet recording apparatus executes printing by discharging ink droplets corresponding to a data signal from a recording head (ink discharge port) onto a recording medium (recording paper). Then, the printed recording medium is conveyed to the discharge side by the conveying means,
The paper is discharged into a predetermined paper stocker. In general, the conveyance means of the recording medium contacts a roll made of an elastic material such as rubber on the side opposite to the printing side of the recording medium, and further contacts a spur on the printing side to move the recording medium toward the roll side. The recording medium is conveyed by pressing and holding the recording medium between the spur and the conveyance roll. A transport means of this type of recording medium is disclosed in Japanese Patent Application Laid-Open No. 7-178988.

[0003]

The disclosed technology relates to a first sheet conveying device for introducing a recording medium from a recording area to a paper discharge area on a paper discharge side of a recording head, and a paper feed apparatus for introducing a recording medium to a paper discharge area. A second sheet conveying device that discharges the recording medium while holding it in a substantially horizontal direction or above the horizontal direction is provided, preventing ink contamination due to contact with the recording head when discharging the paper, and expanding the printable area. It is to let. This technology can hold the recording paper horizontally, so that when the recording paper in the pre-printing area is released from the conveyance means, the rear end of the paper can be prevented from contacting the recording head and being contaminated.
Depending on the transporting means on the discharge side, there is a fear that the print quality at the edge of the paper may be degraded. Further, the two sheet conveying devices in the paper discharge area have led to an increase in the number of assembling steps and an increase in the cost of the device. Accordingly, it is an object of the present invention to economically provide an ink jet recording apparatus which prevents a recording medium from contacting a recording head at the time of paper discharge and enlarges a printable area of the recording medium.

[0004]

According to an aspect of the present invention, there is provided an ink jet recording apparatus comprising: a conveying means for conveying a print medium from an upstream of a printing section to a print area; There is a discharge unit that conveys the medium to the downstream side of the print area and discharges the medium. The discharging means includes a first discharging device disposed near the downstream of the printing area and a second discharging device disposed downstream of the first discharging device. And a configuration in which the conveyance force of the first ejection device is set to be higher than the conveyance force of the second ejection device, for example.

The discharge device is disposed opposite to the driving rotary body for supporting and transporting the printing medium on the opposite side of the printing surface of the printing medium, and rotates in contact with the printing surface of the printing medium. A rotating end of the printing medium discharged from the apparatus, wherein the diameter tolerance and the run-out tolerance of the driving rotating body of the first discharging device are made smaller than those of the driving rotating body of the second discharging device. The printing accuracy is increased and the printing area is expanded.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus comprising: conveying means for conveying a printing medium from a printing section upstream to a printing area; a first discharging apparatus disposed near the downstream of the printing area; And a discharge unit configured to convey the print medium downstream from the print area and discharge the print medium. The first discharging device is composed of a rotating body that rotates in contact with the printing surface side of the printing medium, and the second discharging device is set to have small diameter tolerance and run-out tolerance. A drive rotating body for supporting and transporting, and a rotating body disposed opposite to the drive rotary body and rotating in contact with the print surface side of the print medium; A configuration is provided in which the force is set to be lower than the transporting force of the transporting unit, and a configuration in which the setting accuracy (diameter tolerance, runout tolerance) of the driving rotating body of the second discharging device is reduced.

[0007]

Embodiments of the present invention will be described with reference to the drawings. First Embodiment FIG. 1 is an explanatory diagram of a print medium transport mechanism showing a first embodiment of an ink jet recording apparatus of the present invention. The recording medium P supplied from the upstream side in the ink jet recording apparatus is transported by the transport roll 11 and the pinch roll 1.
3 and is conveyed to the support member 20 in a horizontal state. The recording head 50 is located above the support member 20, and the recording medium P on which recording has been performed using the ink ejected from the recording head 50 is discharged to a recorded paper stocker (not shown) by a discharge-side transport unit. The discharge-side transport unit includes a first discharge device 30 disposed near the discharge side of the recording head 50 and a second discharge device 40 disposed downstream of the first discharge device 30.

[0008] The first discharge device 30 includes a discharge-side first transport roll 31 and a first transport roll 31 provided in contact with the transport roll 31.
, For example, a spur 33 as a pressing member.
The discharge-side first transport roll 31 is a drive rotary roll formed of an elastic body such as rubber for transporting while supporting the surface of the recording medium P opposite to the recording surface. The first spur 33 is a rotating body whose tip is formed in a sharp shape.
To restrict the lifting of the recording medium P in the direction of the recording head. The discharge-side second transport roll 41 is a drive rotary roll formed of an elastic body such as rubber which transports while supporting the surface of the recording medium P opposite to the recording surface.
The spur 43 is a rotating body whose tip is formed in a sharp shape.
The second spur 43 presses the recording surface of the recording medium P to be conveyed to regulate lifting of the recording medium P, and urges the recording medium P to be conveyed in a horizontal state.

At this time, the discharge device 3 provided on the discharge side
The conveying force of 0, 40 is set smaller than the conveying force of the supply-side conveying means 10. Further, in the discharging device, the conveying force of the first discharging device 30 is set to be larger than that of the second discharging device 40. That is, the conveying force of the supply-side conveying means 10> the conveying force of the discharging-side first discharging device 30> the discharging-side second discharging device 30.
And the transfer force of the discharging device 40. Here, the conveyance force of the recording medium forms a difference due to the design accuracy of the diameter tolerance and the run-out tolerance of the transport rolls 11, 31, and 41 of the respective devices that are transported and driven. That is, by setting the diameter tolerance and the run-out tolerance of the transport roll to be small, the transport accuracy is increased, and the transport force is increased.

In the transport roll according to the present invention, a roll which minimizes the diameter tolerance and the run-out tolerance of the transport roll 11 on the supply side is arranged to provide a transport device having the greatest transport force. Next, although the diameter tolerance and the run-out tolerance are slightly larger than those of the transport rolls 11, the second transport roll 31 having a smaller diameter tolerance and run-out tolerance than the transport rolls 41 is arranged.

In the transport device having such a configuration, the recording medium P is subjected to a print recording operation at the lower portion of the recording head 50 while the recording medium P is kept horizontal by the transport rollers 11 on the supply side having high transport accuracy. The recording medium P on which recording has been performed is the first on the discharge side.
Is transported downstream by being supported by the transport rolls 31 of the transport device 30. The trailing end portion of the recording medium P separated from the nip of the supply-side transport means 10 is nipped and transported by the discharge-side first discharge device 30 on the front side in the traveling direction. At this time, since the diameter tolerance and the runout tolerance of the first transport roll 31 are set small, it is possible to form an image with high transport accuracy and high image quality up to the rear end of the recording medium. As described above, the ink jet recording apparatus of this embodiment can achieve an enlargement of the printing range without lowering the image quality. Further, since the second transport roll 41 may be a roll with low accuracy, a transport device with high transport accuracy can be economically provided without using two expensive high-precision rolls.

Embodiment 2 In this embodiment, one of the recording medium ejection devices provided on the ejection side is provided only with a pressing means. FIG. 2 is an explanatory diagram showing this embodiment. The recording medium P supplied from the upstream side is conveyed to the supply side conveyance means 10 including the conveyance rolls 11 and the pinch rolls 13, conveyed horizontally to the support member 20, and recorded by ink ejected from the recording head 50. Is executed. The recorded recording medium P is discharged by a discharge-side transport device. The discharge-side transport device of this embodiment includes a first discharge device 300 including a spur, and a second discharge device including a transport roll 410 and a spur 430. Device 40
Consists of zero.

The first ejection device 300 is composed of a spur arranged near the downstream side of the recording head 50 and is arranged at a position in contact with the upper surface of the support member 20. First discharge device 30
0 presses the upper surface of the recorded recording medium P that advances along the surface of the support member 20 to urge the recording medium P to be transported in a horizontal state. The second discharge device 400 includes a discharge-side transport roll 410 formed of an elastic body such as rubber for supporting and transporting a surface opposite to the recording surface of the recording medium P, and a recording surface of the transported recording medium P. And a second spur 430 for restricting the lifting of the recording medium P by pressing. The transport roll 410 is a driving rotary roll, and the second spur 430 is a rotary body having a sharp tip. At this time, the transport roll 4
Reference numeral 10 is designed to have high design accuracy of diameter tolerance and runout tolerance. Further, the conveying force of the discharging device 400 provided on the discharging side is set to be smaller than the conveying force of the supply-side conveying means 10.

The conveying means according to the present invention minimizes the diameter tolerance and the run-out tolerance of the supply-side transport roll 11, thereby increasing the transport accuracy and transport force of the recording medium P, and increasing the transport roll of the discharge device 400. 410 diameter tolerance,
By setting the runout tolerance to be small, the conveyance accuracy of the rear end portion of the recording medium P remote from the nip of the supply-side conveyance means 10 is increased, and an image with high image quality can be formed up to the rear end of the recording medium. Further, since the discharge device on the discharge side is constituted by one high-precision transport roll, an ink jet recording device capable of expanding the recording range can be provided economically.

(Embodiment 1) Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an ink jet recording apparatus according to the present invention, and FIG. 3 is a cross-sectional explanatory view of the ink jet recording apparatus in a conveying direction of a recording medium. The ink jet recording apparatus 100 performs recording on the recording medium P supplied from the upstream side and located at a horizontal position on the support member 110 by the recording head 120 located above the recording medium P, and the recorded recording medium P is downstream. Is discharged to the side. The recording medium P is, for example,
Consists of paper, postcards, etc.

The recording head 120 is mounted on a carriage 125 in communication with an ink tank 122. The carriage 125 is configured to be slidable by a guide shaft 127 and a guide rail (not shown) extending in a direction perpendicular to the recording paper P transport direction. The position facing the recording head 120 and the ink ejection port surface 120a is the recording position on the recording medium P, and the recording position is the supporting member 110 of the recording medium P.
Are arranged.

On the supply side of the recording medium P with respect to the recording position, a supply side conveying means 130 is provided. Supply side conveying means 1
30 is a first transport roll 131 and a pinch roll 13
Consists of three. The recording medium P conveyed from the direction of arrow A by the paper feeding means (not shown) is conveyed to the recording position by being sandwiched between the conveyance roll 131 and the pinch roll 133. The first transport roller 131 is a high-precision roller having extremely small diameter tolerance and touch tolerance, and has excellent transport accuracy of the recording medium P. A discharge-side first discharge device 150 and a discharge-side second discharge device 160 are provided downstream of the recording position in the discharge direction.

The first discharge device 150 on the discharge side is composed of a second transport roll 151 and a first spur 153 for holding the paper sheet recorded by the recording head 120 and transporting the paper downstream. The second transport roll 151 supports and transports the recording medium P from the back surface (opposite to the recording surface), and the first spur 153 is pressing means for pressing the recording surface of the recording medium P. Is pressed in the direction of the transport roll 151 to urge transport. The transport position of the second transport roll 151 is on the same horizontal plane as the support surface of the support member 110 at the recording position. The second transport roll 151 has small diameter tolerance and runout tolerance (for example, diameter tolerance ± 0.05, runout tolerance 0.05).
Below) high precision rollers.

The second discharge device 160 on the discharge side is disposed downstream of the first discharge device 150,
1 and a second spur 163. Third transport roll 16
1 is a recording medium P sent from the first ejection device 150
Is supported from the back surface (the surface opposite to the recording surface) and transported to the downstream side. The second spur 163 is a pressing unit that presses the recording surface of the recording medium P, and presses the recording medium in the direction of the transport roll 161 to promote transport. Third transport roll 16
The first transport position is the same horizontal plane as the support surface of the support member 11 at the recording position and the support surface of the second transport roll 151 for the recording medium P. The third transport roll 161 has the accuracy such as the diameter tolerance and the runout tolerance.
Set lower than 51.

These transport means are constituted by two transport rolls having an elastic body attached to a rotating shaft in a direction perpendicular to the direction in which the recording medium P is discharged. Spur 153,1
Reference numeral 63 denotes a member having a plurality of sharpened tips, which is attached to a holder 220 provided in the recording apparatus main body. Spurs 153 and 163 are transport rolls 151 and 161
Are provided in correspondence with.

In the transport section of the recording medium P configured as described above, the recording medium P is reliably transported to the lower portion of the recording head 120 by the transport roll 131 which has the smallest diameter tolerance and run-out tolerance and is set with high accuracy. Recorded. Then, the recorded recording medium P is placed on the first side disposed on the discharge side.
The discharge device 150 is conveyed to the discharge side by being pinched by the transport roll 151 and the spur 153 of the discharge device 150, and is pinched by the second discharge device 160. Since the diameter tolerance and the run-out tolerance of the transport roll 151 of the first discharge device 150 are set small, the transport accuracy is good, and the transport of the recording medium P is good. Then, after the trailing end of the recording medium P is separated from the conveying unit 130, the conveying roll 1 with high setting accuracy of the first discharging unit 150 is used.
By 51, it is transported while maintaining a horizontal state. And
The recording medium P passing under the recording head 120 is recorded with good positional accuracy to the rear end.

(Embodiment 2) Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 4 is an explanatory cross-sectional view of the inkjet recording apparatus 500 according to this embodiment in the transport direction of the recording medium. Members similar to those described in the first embodiment are denoted by the same reference numerals. The recording medium P supplied from the upstream side indicated by the arrow A while being clamped by the transport device 130 is transported to a horizontal position on the support member 510. The first transport roller 131 of the supply-side transport device 130 is a high-precision roller having a very small diameter tolerance and very small contact tolerance, and has excellent transport accuracy of the recording medium P. On the downstream side of the recording position in the discharge direction, a discharge-side first discharge device and a discharge-side second discharge device 5 are disposed.
60 are provided.

The first ejection device on the ejection side is composed of a spur 550, and restricts the lifting of the recording medium P toward the recording head 120 by coming into contact with the recording surface of the sheet recorded by the recording head 120. The spur 550 is rotatably disposed in a housing 570 attached to the apparatus main body. Although the contact position of the spur 550 in the drawing with the recording medium P is on the same horizontal plane as the support surface of the support member 510 at the recording position, the spur 550 may be disposed above the recording medium so that the recording medium does not lift and contact the recording head surface. A discharge device 560 is provided downstream of the spur 550. The discharge device 560 includes a second transport roll 561 and a second spur 563. The second transport roll 561 is a high-precision roll having small diameter tolerance and run-out tolerance.

The second transport roll 561 on the discharge side is spur 55
At 0, the upward movement is restricted, and the recording medium P sent while maintaining the horizontal state is supported from the rear surface (opposite to the recording surface) and transported downstream. The second spur 563
Indicates that the recording medium is pressed in the direction of the transport roll 561 to promote transport. The transport position of the second transport roll 561 is on the same horizontal plane as the support surface of the support member 510 at the recording position. The second transport roll 561 has lower accuracy such as a diameter tolerance and a run-out tolerance than the first transport roll 131, but has higher accuracy than a normal transport roll (for example, a diameter tolerance ±
0.05, runout tolerance 0.05 or less).

In the transport section of the recording medium P configured as described above, the recording medium P is reliably fed to the lower portion of the recording head 120 by the transport roll 131 which has the smallest diameter tolerance and run-out tolerance and is set with high accuracy. Recorded. Then, the recorded recording medium P is conveyed to the discharge side while being sandwiched between the conveyance roll 561 and the spur 563 of the discharge device 560 disposed on the discharge side. The transport roll 561 is a roll having a small diameter tolerance and a small run-out tolerance and having good transport accuracy, and has a good transport of the recording medium P. After the trailing end of the recording medium P is separated from the conveying means 130, the recording medium P is conveyed while maintaining a horizontal state by the conveying roll 561 having a high setting accuracy of the discharging means 560, and the conveyed recording medium P is driven by a spur 550. Movement to the upper part is regulated, the horizontal state of the medium is maintained, and ink contamination due to contact of the recording medium P with the recording head 120 is prevented. As described above, also in the recording apparatus shown in this embodiment, the recording medium P passing under the recording head 120 is recorded with good positional accuracy to the rear end.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a first embodiment of a transport mechanism.

FIG. 2 is an explanatory view showing a second embodiment of the transport mechanism.

FIG. 3 is a cross-sectional view of the inkjet recording apparatus according to the first embodiment.

FIG. 4 is a cross-sectional view of an inkjet recording apparatus according to a second embodiment.

[Explanation of symbols]

10, 130 supply-side transport means, 11, 131 transport roll, 13, 133 pinch roll, 20, 11
0 support member, 30, 150, 550 first discharger, 31, 151 transport roll, 33, 153, 3
00,550 spurs, 40,160,400,560
Second discharger, 41,161,410,561 transport roll, 43,163,430,563 spur,
50,120 recording head, 100,500 inkjet recording apparatus.

Claims (4)

[Claims] 1. An ink jet recording apparatus comprising: transport means for transporting a print medium from a printing section upstream to a print area; and discharge means for transporting the print medium to a downstream side of the print area and discharging the print medium. The transporting force is set lower than the transporting force of the printing medium of the transporting means, and the discharging means is provided at a first discharging device disposed near the downstream side of the printing area and at a downstream side of the first discharging device. An ink jet recording apparatus, comprising a second discharge device that performs printing, and a conveyance force of the print medium of the first discharge device and a conveyance force of the print medium of the second discharge device. 2. The ink jet recording apparatus according to claim 1, wherein the discharging means sets the conveying force of the first discharging device higher than the conveying force of the second discharging device. 3. A discharge device is disposed opposite to the drive rotary member for supporting and transporting the print medium on the opposite side of the print surface, and is rotated in contact with the print medium on the print surface side. A rotating body, wherein a diameter tolerance and a run-out tolerance of a driving rotating body of the first discharging device are set smaller than a driving rotating body of the second discharging device, and a conveying force is set higher. 2. The ink jet recording apparatus according to 1. 4. An ink jet recording apparatus comprising: a transport unit for transporting a print medium from an upstream of a print unit to a print area; and a discharge unit for transporting a print medium to a downstream side of the print area and discharging the print medium. And a second discharge device disposed downstream of the first discharge device, the first discharge device being in contact with the printing surface side of the print medium. The second discharge device is composed of a rotating rotator, and the second discharging device is disposed opposite to the driving rotator for supporting and transporting the opposite side of the printing surface of the printing medium, and is disposed on the printing surface side of the printing medium. A rotating body that rotates in contact with the printing medium, the transport force of the print medium of the second discharging device is set to be lower than the transport force of the transporting means, and the diameter tolerance and the deflection of the driving rotating body of the second discharging device. An inkjet recording device with a small tolerance.