JPH08216469A - Recording sheet float-preventing device for ink jet printer - Google Patents

Abstract

PURPOSE: To obtain stable printing quality by preventing the floating of a recording sheet having a curling trend at the time of printing and obtaining flatness in an ink jet printer using a roll sheet. CONSTITUTION: A recording sheet retaining member which fluctuates in correspondence with the feeding direction of a carriage 1 and retains the recording sheet P of the forward side of the feeding direction of a print head 3 is provided at a carriage. The member has the substantially the center of a Y-form rocking lever 5 as a rotary fulcrum, sheet retaining rolls 6, 7 at the ends of first and second levers, and an energizing member 12 for energizing the end of a third lever toward the center. When the carriage 1 is fed to the feeding end, the third lever is pressed by switching pins 10, 11 provided at both feeding ends to rotate the lever 5, thereby switching the rolls 6, 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printing apparatus mounted on a facsimile machine, a printer or the like, and a device for preventing floating of a recording paper with curl pull out from a roll of plain paper at the time of printing. Is.

[0002]

2. Description of the Related Art Generally, a recording paper is conveyed by a pair of a feed roller and a pressure roller in a facsimile machine, a printer or the like, which is the most stable, but in an ink jet recording system, ink is dried immediately after printing. Is insufficient, there is a problem in that the pair of rollers firmly sandwiches and conveys. That is, the recording surface after printing is rubbed by the roller, which deteriorates the image quality. Therefore, a roller having a shape close to point contact is used on the pressure roller side, and moreover, only a conveying force to which a pressure is not applied can be applied.

Also, in the case of conveying a normal cut sheet (sheet paper), even such a conveying force does not affect printing, but in the case of a recording sheet wound in a roll and having curl, It is not possible to provide sufficient tension with a transporting force such as contact, and it is not possible to secure the flatness of the recording paper surface.

Although the printing method is not the ink jet recording method, in order to convey an electrostatically printed image before fixing,
An example of applying a point-contact roller to the recording paper surface (toner printing surface) to secure the transport force and prevent the recording paper from floating is Jikkai Sho 61.
-28746 is disclosed.

[0005]

In conventional machines (heat-sensitive machines, heat-sensitive transfer machines and some laser machines) that use roll-shaped recording paper, most of them are mainly due to the problem of stacking performance of recording paper after printing. This device is equipped with a decurling (curl removal) mechanism. These decurling mechanisms are simple ones that simply pull the paper in the opposite direction to remove the curl.Tension is applied to the roller-shaped member and this tension force is adjusted according to the curl amount of the recording paper (the outer circumference of the roll). There are many types of mechanisms, including a mechanism that changes the amount of curl between a part and the vicinity of a paper tube) and always performs a constant decurling. However, what can be said in any configuration is a mechanism for rolling the paper in a roll shape and forcibly curving the paper with the curl in the opposite direction to correct the habit, so it can be said that it is a decal. It is unavoidable that a periodic waviness is left on the paper surface due to the reverse tension during decal.

In a heat-sensitive machine (heat-sensitive transfer machine) or a laser machine, the above-mentioned short-wave undulation of the recording paper is unlikely to cause a problem of affecting an image at the time of print recording.
In the ink jet recording system targeted by the present invention, the recording paper cannot be stably pressed at the time of printing like a heat sensitive machine or a laser machine, and the printing must be performed with the paper surface being substantially free. Therefore, there is a possibility that even a small ripple on the recording paper may affect the image, which is a problem that cannot be ignored.

In the conventional ink jet printer,
To prevent the paper from floating up by moving the position of the recording paper conveyance roller close to the position just before the print head, or by providing a U-shaped guide outside the print recording range and passing the paper through the guide, lift the paper. The flatness of the printing paper surface was secured by methods such as suppression. However, most conventional inkjet printers use cut paper, and in the case of roll-cut paper with minute waviness, the stability of the paper can be achieved only by approaching the transport roller position and transport guide as described above. Cannot be secured.

Further, even the conventional machines are equipped with a paper discharging roller for the purpose of discharging the recording paper after printing, and the corrugation of the paper can be removed by pulling the paper with this roller. However, if the ink immediately after printing is conveyed with a strong force before the ink is still dry, the image quality may be deteriorated due to the rubbing of the printing surface, and it is practically difficult to give the paper ejection roller a large conveying force.

The present invention is intended to solve the above-mentioned conventional problems, and in an ink jet printing apparatus using roll paper, minute waviness on the recording paper after decurling is more actively removed than before, and printing is performed at the time of printing. (EN) It is possible to provide a recording paper floating prevention device that stabilizes the paper surface and improves print quality, which enables the use of roll paper in inkjet printing devices and improves the versatility of inkjet printing devices. To aim.

[0010]

In order to achieve the above-mentioned object, the recording paper floating prevention device of the ink jet printing apparatus of the present invention firstly (1) pulls out a roll of plain paper and defines it before or after recording. In an inkjet printing device that carries recording paper that is automatically cut to size and prints with an inkjet print head that is mounted on a carriage that runs in a direction perpendicular to the direction in which the recording paper is carried The recording paper pressing member is configured to swing correspondingly and press the recording paper on the front side in the moving direction of the inkjet print head.

(2) The recording paper pressing member has first and second recording mediums with a substantially central portion of a three-pronged rocking lever serving as a rotation fulcrum.
Has a paper pressing roller at the tip of the lever and an urging member for urging the tip of the third lever toward the central portion. The third pin is pushed by the provided switching pin and the swing lever is rotated to switch the paper pressing roller.

Also, (3) pull out a roll of plain paper,
It is provided on the carriage of an inkjet printing device that carries recording paper that is automatically cut to a specified size before or after recording, and prints with an inkjet print head that is mounted on the carriage that runs in a direction perpendicular to the direction in which the recording paper is carried. A recording paper pressing member that presses the recording paper on the unrecorded side against the print line printed by the inkjet print head as the carriage runs and separates from the recording paper when transporting the recording paper so as not to hinder the transfer And

(4) In the above ink jet printing apparatus, recording paper suction means provided on the back surface of the recording paper near the print line printed by the ink jet print head as the carriage travels, and driving of this recording paper suction means. And a driving force transmitting means for transmitting a force from a driving source for moving the carriage, and the suction operation of the recording paper suction means is synchronized with the traveling operation of the carriage.

(5) In the above ink jet printing apparatus, the ink jet print head is provided on both sides of a recording paper discharge mechanism provided near the print line for printing by the carriage as the carriage travels, and is located outside the print area of the recording paper. It is composed of means for applying a pulling force to the portion toward the outside.

[0015]

According to the configuration of (1), the recording paper pressing member swings in correspondence with the traveling direction of the carriage, and always presses the recording paper on the front side in the moving direction of the print head. The distance between the print head and the recording paper surface is always constant without the recording paper rising from the back member.

Further, in the configuration of (2), the swinging lever is pushed by the switching pin at the traveling end portion of the carriage to rotate,
Since the paper pressing roller is automatically switched, the recording paper on the front side in the moving direction of the print head can be pressed.

Further, according to the configuration of (3), the recording paper on the unrecorded side is pressed near the printing line, and the flatness of the recording paper is always ensured during printing.

Further, according to the configuration of (4), since the recording paper is sucked by the recording paper suction pipe in the vicinity of the print line, the recording paper is prevented from being lifted up and the recording paper suction operation is performed by the carriage traveling operation. In synchronism with the above, the timing of conveying the recording paper is also favorably performed. Further, since the driving force of the recording paper suction means is taken out from the driving source of the carriage,
It is extremely economical.

Further, according to the configuration of (5), since the recording paper near the printing line is pulled outward, minute waviness of the recording paper is flattened and the printing performance can be stabilized.

[0020]

Embodiments will be described in detail below with reference to the drawings. FIG. 1 shows a main part of an inkjet printing apparatus according to a first embodiment of the present invention, in which 1 is a carriage base (hereinafter referred to as a carriage), 2 is an ink tank, 3 is an inkjet print head (hereinafter referred to as a print head). Say),
Reference numeral 4 is a guide shaft, 5 is a swing lever, 6 and 7 are paper pressing rollers, 8 is a drive belt, 9 is a drive motor, 10 and 11 are switching pins, and P is recording paper. The drive belt 8 is a drive motor 9
Is connected to the pulley and the carriage 1 is locked to the drive belt 8.

The ink jet printing apparatus to which the present invention is directed pulls out a roll of plain paper, or conveys a recording paper P which is cut into a prescribed size in advance by an automatic cutting machine (not shown), and in the conveying direction of the recording paper. On the other hand, printing is performed by ejecting ink from a print head 3 mounted on a carriage 1 that runs in a direction perpendicular to the print head. As shown in FIG. 2, the carriage 1 is provided with a recording paper pressing member that swings corresponding to the traveling direction of the carriage.

In the recording paper pressing member, the substantially central portion of the three-pronged rocking lever 5 serves as a rotation fulcrum 5a, and the first lever 5b.
The carriage 1 has the paper pressing rollers 6 and 7 at the tip of the second lever 5c, and the spring 12 as a biasing member for pulling the tip of the third lever 5d toward the central portion. At that time, the lever 5d is pushed by the switching pins 10 or 11 provided at the trailing end of the traveling, and the swing lever 5 is rotated as shown by an arrow A to switch the paper pressing rollers 6 and 7.

Next, the operation of this embodiment will be described. The recording paper P is conveyed in a direction perpendicular to the paper surface of FIG. The carriage 1 travels along the guide shaft 4 while being pulled by the drive belt 8 by the rotation of the drive motor 9, and printing is performed by the ink ejected from the print head 3.

Now, when the carriage 1 travels from the right side to the left side of the paper and reaches the end of travel, the switching pin 10 causes the swing lever 5 to move.
Since the third lever 5d of is pressed, the swing lever 5 is rotated clockwise, and the paper pressing roller 7 projects to press the recording paper surface,
The paper pressing roller 6 moves backward. In this state, the carriage 1 prints while moving from left to right on the paper surface. When the carriage reaches the traveling end on the right side, the switching pin 11 pushes the third lever 5d of the rocking lever 5, so that the rocking lever 5 rotates counterclockwise and the paper pressing roller 6 projects to record. The paper surface is pressed down, and the paper pressing roller 7 moves backward. Carriage 1 in this state
Prints while moving from right to left on the paper. That is, the swing lever 5 swings in accordance with the traveling direction of the carriage 1, and printing is performed while pressing the recording paper on the front side in the moving direction of the print head 3.

In the present embodiment having the above-described structure, since the printing progresses while the printing head 3 presses the surface of the printing paper immediately before printing, the printing paper and the printing head 3 do not float up from the back member. The distance from the paper surface is always constant and printing quality is stable.

FIGS. 3 and 4 show a second embodiment of the present invention, in which the same reference numerals as those in FIG. 1 represent the same elements, and 14 is a rotation fulcrum 14a at the substantially central portion. Is a rotating lever, 15 is a paper pressing roller, 16 is a spring for pressing the paper pressing roller 15 against the recording paper P, 17 is a paper pressing roller 15
Is a solenoid that separates from the recording paper P. The rotating lever 14 and the paper pressing roller 15 are provided in the carriage 1 at positions where the recording paper P on the unrecorded side is pressed in the vicinity of the print line printed by the print head 3 as the carriage travels. Further, when the recording paper is conveyed, a solenoid 17 is provided to separate the paper pressing roller 15 from the recording paper so as not to hinder the conveyance.

Also in this embodiment, during printing, the recording paper in the vicinity of the print head 3 is pressed to maintain the flatness, so that stable printing can be performed and the printing quality can be improved.

FIGS. 5 and 6 show a third embodiment of the present invention, in which 18 is a recording paper suction pipe provided on the back surface of the recording paper near the print line printed by the print head 3. In addition, small holes are opened at regular intervals in the portion in contact with the recording paper. Reference numeral 19 is a fan that is provided at one end of the recording paper suction pipe 18 and sucks air in the recording paper suction pipe 18. Reference numeral 20 is a driving force transmission that transmits a driving force for the fan 19 from a drive motor 9 that is a driving source for carriage travel. A mechanism, reference numeral 21 is a paper discharge roller for discharging printed recording paper.

In such a configuration, the recording paper P is conveyed in the direction of arrow B in FIG. 6, the carriage 1 is run in the direction perpendicular to the conveying direction of the recording paper P, and printing is performed by the print head 3. At this time, the recording paper P is sucked in the vicinity of the print line by the recording paper suction pipe 18, so that the recording paper does not float and stable printing is performed. When the carriage 1 reaches the trailing end portion and stops, the drive motor 9 also stops driving the fan 19 in synchronization therewith, so that suction of the recording paper P is also released, and the recording paper is conveyed in the meantime.

The drive motor 9 rotates in the forward and reverse directions according to the traveling of the carriage 1 in both directions. The drive mechanism portion of the fan 19 is provided with a mechanism (not shown) that always rotates in one direction. Therefore, the suction force can be generated regardless of the reciprocating movement of the carriage 1.
Further, since the driving force transmission mechanism 20 drives the fan 19 after sufficiently increasing the rotation speed of the motor, even if the rotation speed of the motor (particularly the pulse motor) is low, sufficient suction force can be obtained. Can be secured.

FIGS. 7 and 8 show a fourth embodiment of the present invention, in which 21 is a discharge roller for discharging recording paper, which is provided in the vicinity of the print line for printing by the print head 3, and 22 is a discharge roller. The recording paper P passes through this by the discharge pressure roller. 23 is the paper discharge roller
On both sides of 21, the skew-driving rollers and 24, which are skew-driven rollers provided outside the print area L of the recording paper P, apply a pulling force outward to the recording paper P passing between them.

In this embodiment thus constructed, the recording paper P in the vicinity of the printing line is pulled outward, so that the recording paper does not float up, the flatness is secured, and the printing performance is stabilized. You can

[0033]

As described above, according to the present invention,
Since the carriage is provided with a recording paper pressing member that swings in accordance with the traveling direction of the carriage and presses the recording paper on the front side in the moving direction of the print head, the recording paper does not float up from the back member during printing, and the print head The distance between the recording paper surface and the recording paper surface is always constant, and the print quality is stable.

The recording paper pressing member is pushed and rotated by the switching pin at the traveling end of the carriage to automatically switch the paper pressing roller, so that the structure is simple and inexpensive to implement. can do.

Further, even when the recording paper pressing member is provided near the printing line at a position for pressing the recording paper on the unrecorded side, the flatness of the recording paper is always ensured at the time of printing to improve the printing quality. I am able to.

Further, in the structure in which the recording paper is sucked by the recording paper suction pipe in the vicinity of the printing line, the recording paper is prevented from being lifted up, stable printing quality is obtained, and it is synchronized with the traveling of the carriage. Therefore,
The recording paper is conveyed at a good timing, and the driving force of the recording paper suction means is taken out from the drive source of the carriage, which is extremely economical.

Further, in the structure in which the recording paper near the printing line is pulled outward, the waviness of the recording paper is flattened and the printing performance can be stabilized.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a first embodiment of the present invention.

FIG. 2 is a detailed view of a recording paper pressing member provided on the carriage according to the first embodiment of the present invention.

FIG. 3 is a plan view of an essential part of a second embodiment of the present invention.

FIG. 4 is a side view of the second embodiment of the present invention.

FIG. 5 is a plan view of an essential part of a third embodiment of the present invention.

FIG. 6 is a perspective view of a main part of a third embodiment of the present invention.

FIG. 7 is a front view of a main part of a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a paper discharge roller and a skew driving / driven roller portion according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 ... Carriage, 3 ... Print head, 5 ... Swing lever, 6, 7, 15 ... Paper pressing roller, 9 ... Drive motor,
10, 11 ... Switching pin, 12, 16 ... Spring, 14 ... Rotating lever, 17 ... Solenoid, 18 ... Recording paper suction pipe,
19 ... Fan, 20 ... Driving force transmission mechanism, 21 ... Paper ejection roller, 23 ... Oblique driving roller.

Claims (5)

[Claims] 1. An ink jet print head mounted on a carriage that pulls out a roll of plain paper, conveys a recording paper that is automatically cut to a specified size before or after recording, and runs in a direction perpendicular to the recording paper conveyance direction. In an inkjet printing apparatus that performs printing by means of a recording paper pressing member that is provided on the carriage, swings corresponding to the traveling direction of the carriage, and presses the recording paper on the front side in the moving direction of the inkjet print head. A device that prevents the recording paper from floating up in an inkjet printing device. 2. The recording paper pressing member uses a substantially central portion of a three-pronged rocking lever as a fulcrum of rotation, and a paper pressing roller is provided at the tip portions of the first and second levers, and a tip portion of the third lever. And a biasing member that biases the swing lever toward the central portion, and when the carriage reaches the trailing end portions, the third lever is pushed by the switching pins provided at both the trailing end portions to swing the lever. The recording paper floating prevention device for an ink jet printing apparatus according to claim 1, wherein the paper pressing roller is switched by rotating the. 3. An inkjet print head mounted on a carriage that pulls out a roll of plain paper, conveys a recording paper that is automatically cut to a prescribed size before or after recording, and runs in a direction perpendicular to the conveying direction of the recording paper. In an inkjet printing apparatus that performs printing by means of a carriage, the recording paper on the unrecorded side is held against the print line printed by the inkjet print head as the carriage travels, and the recording paper is transported when it is transported. A recording paper floating prevention device for an ink jet printing apparatus, comprising a recording paper pressing member which is separated from the recording paper so as not to interfere with the recording paper. 4. An ink jet print head mounted on a carriage that pulls out a roll of plain paper, conveys a recording paper that is automatically cut to a specified size before or after recording, and runs in a direction perpendicular to the recording paper conveyance direction. In the inkjet printing apparatus that performs printing by the above-described method, the recording paper suction means provided on the back surface of the recording paper near the print line printed by the inkjet print head and the driving force of the recording paper suction means are set as described above. A recording paper floating prevention device for an ink jet printing apparatus, comprising: a driving force transmitting means for transmitting from a driving source for moving a carriage, wherein the suction operation of the recording paper suction means is synchronized with the traveling operation of the carriage. 5. An ink jet print head mounted on a carriage that pulls out a roll of plain paper, conveys a recording paper that is automatically cut into a prescribed size before or after recording, and runs in a direction perpendicular to the recording paper conveyance direction. In an inkjet printing apparatus that performs printing by means of an inkjet printing apparatus, the inkjet printing head is provided on both sides of a recording paper discharging mechanism provided in the vicinity of a printing line for printing with the traveling of the carriage, and is provided outside the printing area of the recording paper. A recording paper floating prevention device for an ink jet printing apparatus, characterized in that the device comprises a means for applying a pulling force toward one side.