JPH1081006A - Paper feeding mechanism of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the tip end and rear end of printing paper from being in contact with the face of a printing head by furnishing a first printing paper compressing guide member on the upstream side of a feeding roller, and a second printing paper intake guide member on the downstream side of the feeding roller. SOLUTION: Through rotation of a feed roller 12, the tip end of printing paper P is conveyed in a manner that it is pressed on the guide face 15b of a guide roller 15 along the roller face of a feed roller 12 by a pinch roller 20 (a first guide member). When the guide face 15b is pressed down, an interstice between it and the head face of a printing head 3 adds to such that the tip end of the paper P is not in contact with the head surface; as a consequence, the paper P does not foul by a marking material. When the rear end side of the paper P is held between a feed roller 13 and pinch rollers 24, 25 (a second guide member), the paper P is pressed down onto the guide face 15b by the pinch roller 24, so that the rear end part of the paper P does not come in contact with the face of the printing head 3 and the paper P does not foul.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid marker such as an ink.
The present invention relates to a paper feed mechanism of a printer device using a king material.

[0002]

2. Description of the Related Art Conventionally, in a printer apparatus using a liquid marking material such as ink, for example, an ink jet printer, a feed roller pressed against a printing sheet is driven to rotate, and a space between the feed rollers is provided. There is a type in which paper is fed along a guide surface of a guide member arranged opposite to a print head.

[0003]

In the paper feed mechanism of the conventional printer, when the print paper is fed, when the leading end or the rear end of the print paper is located near the print head, Since the paper is free, if the paper has a curl at the edge or if the paper becomes slack during transportation, the leading edge or the trailing edge of the printing paper may come into contact with the head surface of the print head. Therefore, there is a problem that the toner is stained by the marking material.

Further, facing the head surface of the print head,
Although a guide member for guiding the printing paper is provided, a predetermined gap must be provided with respect to the printing head so as to be compatible with printing papers having different thicknesses. When the portion is located near the print head, it becomes unstable, and there is a problem that the print quality is reduced.

The present invention provides a paper feed mechanism for a printer apparatus which does not contact the head surface of a print head even when it becomes free when the leading or trailing end of the print paper is located near the print head. It is intended to be.

[0006]

In order to achieve the above object, in a paper feeding mechanism of a printer according to the present invention, a feeder disposed upstream of a print head is provided with a printing paper. A first guide member is provided so as to be pressed against the guide surface, and a second guide member is provided on the downstream feed roller so as to take in the printing paper conveyed along the guide surface. .

[0007]

Embodiments of the present invention will be described with reference to the drawings. Elements common to the drawings are denoted by the same reference numerals. Form view of a first embodiment 1 is A-A cross-sectional arrow view of the printer apparatus shown in FIG. 2,
FIG. 2 is a perspective view of a printer equipped with the paper feed mechanism according to the first embodiment.

As shown in FIG. 1, an ink-jet print head 3 (hereinafter referred to as a print head 3) is mounted on a carriage 2 which is movable in an arrow CD direction perpendicular to an arrow B direction which is a paper feed direction. Described). The carriage 2 is slidably provided at both ends on a shaft 5 supported by the frame 4. The frame 4 is provided with a motor 7 supporting the pulley 6 and a shaft 9 rotatably supporting the pulley 8. A belt 10 is wound around the pulleys 6 and 8. It is hung. The carriage 2 is fixed to the belt 10, and moves in the direction of arrow CD by the forward and reverse rotation of the motor 7.

The frame 4 is erected on the base plate 11, and has a plurality of comb-like guide portions 4a parallel to the transport direction so as to guide the printing paper P to the printing head 3.

[0010] A paper transporting the printing paper P in the direction of arrow B
The drawers 12 and 13 are arranged in parallel with the shaft 5. As shown in FIG. 2, the shaft 12a of the feed roller 12 is compressed by compression coil springs 14a and 14b.
The guide member 15 supported by the plate 11 is held by a U-shaped shaft holding portion 15a.

The guide member 15 has a guide surface 15b for guiding the printing paper P, and guide pins 15c and 15d which slide along guide grooves 11a and 11b provided on the base plate 11. The relationship between the guide surface 15b and the roller surface of the feed roller 12 is kept constant.

The shaft 13a of the feeder 13 is supported by the base plate 11 via a bearing member 16 and a compression coil spring 17.

A pinch roller as a first guide member is provided on the outer periphery of the feed roller 12 on the upstream side with respect to the print head 3 so that the printing paper P is pressed against the guide surface 15b of the guide member 15. 19 and 20 are arranged at shifted positions. The pinch rollers 19 and 20 are rotatably supported by a first roller holder 21 and a second roller holder 22, respectively, and have compression coil springs 14a and 14b.
The roller is in contact with the roller surface of the feed roller 12 urged by.

As shown in FIG. 1, the first roller holder 21 and the second roller holder 22 are alternately arranged along the axial direction of the feed roller 12. The first roller holder 21 has shaft portions 21a, 21a on the side walls, and the guide portions 4a, 4a of the frame 4 span the grooves between the guide portions 4a, 4a.
4a.

The second roller holder 22 has a groove 22 on the side wall.
a, 22a, the shaft portions 21a, 2a of the first roller holder 21 straddling the groove between the guide portions 4a, 4a of the frame 4.
1a, the pinch roller 20 is brought into contact with the feed roller 12 by the urging force of a tension coil spring 23 stretched between the rear end and the frame 4. I have.

As shown in FIG. 2, a guide member 1 is provided on the outer periphery of the feeder 13 on the downstream side with respect to the print head 3.
5, a spur-shaped pinch roller 2 serving as a second guide member for taking in the printing paper P conveyed along the guide surface 15b
Reference numerals 4 and 25 are arranged at shifted positions.

As shown in FIG. 1, the pinch rollers 24 and 25 are rotatably supported by a roller holder 27 fixed to a bracket 26 provided on the frame 4 and urged by a compression coil spring 17. Feeder 13
Is in contact with the roller surface. The reason why the pinch rollers 24 and 25 are spur-shaped is to prevent the printed ink from being stained by the pinch rollers coming into contact with the paper surface on which the printed ink has not yet dried.

At one end of the feed rollers 12 and 13,
Gears 27 and 28 are provided, respectively.
9. A driving force is input from the motor 33 via the intermediate gears 30, 31, 32 (the intermediate gear 31 is not shown), and the printing paper P is rotated so as to be conveyed in the arrow B direction.

FIGS. 3 to 5 are state diagrams (1) to (3) for explaining the operation of the paper feeding mechanism according to the embodiment, and only elements necessary for the explanation are described for clarity. FIG. 6 is a schematic diagram illustrating the conveying force.

Next, the operation will be described. When the printer 1 receives a print and paper feed start command from a higher-level device (not shown), it feeds out one sheet of print paper P from a cassette (not shown) and the leading end of the print paper P is And is transported until it is clamped by the rack 19.

Next, the printer 1 drives the motor 33 and rotates the feed roller 12, and as shown in FIG. 3, the leading end of the printing paper P is moved by the pinch roller 20.
A guide member 15 extends along the roller surface of the feed roller 12.
Is conveyed so as to be pressed against the guide surface 15b.

The guide member 15 is pushed down on the leading end of the printing paper P, and is pushed down against the urging force of the compression coil springs 14a and 14b. The pinch roller 20 is driven by the tension force of the tension coil spring 23 so that the feed roller 12
The roller follows the roller surface of the feed roller 12 while being in contact with the roller surface.

The guide member 15 stops at a position where the pressing force of the printing paper P and the urging force of the compression coil springs 14a and 14b are balanced, and the printing paper P is conveyed along the guide surface 15b of the guide member 15.

When the guide surface 15b of the guide member 15 is depressed, the gap between the print head 3 and the head surface increases, so that the paper may have a curl at the leading end thereof or may be slackened during conveyance. Since the leading end of the printing paper P does not contact the head surface of the printing head 3, the printing paper P is not stained by the marking material.

Further, when the feeder 12 rotates and the printing paper P is conveyed, as shown in FIG. 4, the leading end of the printing paper P becomes the feeder 13 and the pinch rollers 24,
25. The feed roller 13 is set so that the feed amount is larger and the feed force is smaller than that of the feed roller 12, so that the feed roller (not shown) holding the leading end side of the printing paper P is held. -The printing paper P is stretched straight between the rollers. The second roller holder 22 is made of a tension coil spring 2 by a printing paper P stretched straight.
The pinch roller 20 is turned around the shaft portion 21a in the direction of arrow E against the urging force of 3 to separate the pinch roller 20 from the roller surface of the feed roller 12.

Further, the feed rollers 12 and 13 rotate to convey the printing paper P, and the printing operation is completed, and the trailing end of the printing paper P is connected to the feed roller 12 and the pinch roller 1.
9 and 20, the second roller holder 22 is rotated in the direction of arrow F by the urging force of the tension coil spring 23, and the pinch roller 20 is brought into contact with the roller surface of the feed roller 12. Contact.

When the printing paper P is conveyed by the pinch rollers 19 and 20 so as to be pressed against the guide surface 15b of the guide member 15, the guide member 15 is pressed down on the printing paper P and the compression coil springs 14a and 14b are pressed. Pushed down against the bias. The pinch roller 20 is driven by the tension force of the tension coil spring 23 so that the feed roller 12
Following the feed roller 12 while contacting the roller surface.

The guide member 15 stops at a position where the pressing force of the printing paper P and the urging force of the compression coil springs 14a and 14b are balanced, and the printing paper P is conveyed along the guide surface 15b of the guide member 15.

Further, when the feed rollers 12, 13 rotate and the printing paper P is conveyed, the rear end of the printing paper P reaches the guide surface 15b of the guide member 15, as shown in FIG. I do.

The trailing end of the printing paper P is the feed roller 13.
When the printing paper P is sandwiched between the printing paper P and the pinch rollers 24 and 25, the printing paper P is pushed down to the guide surface 15b of the guide member 15 by the pinch roller 24. Since the rear end of the printing paper P does not contact the head surface of the print head 3 even when a curl is provided at the rear end or when the paper is slackened during conveyance, the mark is not formed.
The printing paper P is not stained by the king material.

Here, referring to FIG.
The reason 3 indicates that the conveying force is smaller than that of the feeder 12. The conveying forces of the feed rollers 12 and 13 are F1 and F2, respectively, the urging force of the compression coil spring 14a is T1, the friction coefficient μ1 of the feed roller 12, and the pinch roller with respect to the center of the feed roller 12. La 19, 2
If the angle θ1 is 0,

[0032]

(Equation 1)

And F1> F2.

In this embodiment, the shaft holding portion of the guide member has a U-shape, but may have a hole shape to be fitted to the feed roller.

According to the first embodiment, the first and second
As a pinch roller is used as a guide member, the printing paper is pressed along the feed roller surface and is conveyed toward the guide surface with a strong conveyance force. When the rear end is located near the print head, the guide member is pushed down, the gap between the head surface of the print head and the material guide surface of the guide portion is widened, and the front end or the rear end of the printing paper is the head surface. To prevent contamination by the marking material.

Also, since the leading end of the printing paper is conveyed by the pinch roller so as to be wound around the upstream feed roller, the contact area becomes large, and a large feeding force is obtained, so that the printing paper is stable. In addition to obtaining the feed force, the drive motor for driving the feed roller can be reduced in size and the transport speed can be increased.

In the pinch roller disposed on the outer periphery of the upstream feed roller, the pinch roller having the highest step relative to the guide surface is fixed, and the pinch roller disposed toward the guide surface is fixed. The pinch roller, which can be pressed freely, is lifted by the print paper sandwiched between the feed rollers, and the gap between the print head surface and the print paper is suitable for printing. Gap can be maintained.

Further, the fixed pinch roller is rotatably provided on the first roller holder fixed to the frame of the printer, so that it is appropriately balanced in the axial direction of the feed roller. Can be placed.

The detachable pinch roller is rotatably provided on a second roller holder rotatably supported by an adjacent first roller holder, and the pinch roller is provided with a filter. By providing an urging member at the rear end side of the roller holder so as to follow the roller surface of the drawer, a pinch roller that allows the leading end of the printing paper to freely contact and separate from the feed roller. When the print paper is held between the print head and the print head, the print paper is conveyed so as to be pressed against the guide surface. When it is sandwiched between the rollers, it is lifted by the printing paper, the gap between the print head surface and the printing paper can be maintained at a gap suitable for printing, and the printing quality can be improved.

Second Embodiment FIG. 7 is equipped with a paper feed mechanism according to a second embodiment corresponding to the sectional view taken along line AA of the printer shown in FIG. 2 according to the first embodiment . FIG. 2 is a cross-sectional view of the printer device taken along line AA.

The second embodiment is different from the first embodiment in that a pinch roller which is displaceable in the outer circumferential direction of the feed roller and which can be freely moved is replaced with a feed roller. An arc surface along the outer peripheral direction of the roller is provided at an end of the roller holder. That is, arcuate surfaces 40a and 41a and 41b are provided at the ends of the roller holders 40 and 41 which rotatably support the pinch rollers 19 and 24 which have the highest level difference with respect to the guide surface 15b.

The roller holder 40 is fixed to the frame 4 like the first roller holder 21 in the first embodiment, and the roller holder 41 is attached to the bracket 26 like the roller holder 27. It is fixed.

In operation, the arc surface 40a of the roller holder 40 is replaced with the printing paper P instead of the pinch roller which can be freely moved.
Is guided to press against the guide surface 15b,
Except for the take-in point, the printing paper conveyed so that the arc surface 41a of the roller holder 41 is pressed against the guide surface is the same as in the first embodiment, and therefore the description is omitted.

According to the second embodiment, the pinch roll
Since members such as a roller, a rotatable roller holder, and a tension coil spring are not required, the structure is simplified.

[0045]

Since the present invention is configured as described above, it has the following effects.

A first guide member is provided on the feed roller disposed on the upstream side with respect to the print head so that the printing paper is pressed against the guide surface. Is provided with a second guide member to take in the printing paper conveyed along the guide surface, so that when the leading end or the trailing end of the printing paper is located near the print head, Since the print head does not come into contact with the head surface even when the mark becomes negative, the mark is not stained by the marking material.

The guide member has a shaft holding portion for holding the shaft of the upstream feed roller and is supported by an urging member. The guide member has a guide surface and a roller surface of the feed roller. Is maintained constant, it is possible to maintain the gap between the print head and the print paper regardless of the thickness of the print paper, thereby improving print quality.

[Brief description of the drawings]

FIG. 1 is a sectional view of the printer device shown in FIG.

FIG. 2 is a perspective view of the printer device according to the first embodiment.

FIG. 3 is a state diagram (1) illustrating the operation of the paper feed mechanism.

FIG. 4 is a state diagram (2) illustrating the operation of the paper feed mechanism.

FIG. 5 is a state diagram (3) illustrating the operation of the paper feeding mechanism.

FIG. 6 is a schematic diagram illustrating a conveying force.

FIG. 7 is a diagram illustrating an AA of a printer according to a second embodiment;
It is a sectional arrow view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer apparatus 3 Print head 12, 13 Feed roller 15 Guide member 19, 20, 24, 25 Pinch roller

Claims (7)

[Claims] 1. A printer device for rotating a feed roller pressed against printing paper and feeding the paper along a guide surface of a guide member disposed between the feed roller and facing a print head. In the paper feed mechanism, a first guide member is provided on a feed roller disposed on the upstream side with respect to the print head so that the printing paper is pressed against the guide surface. A paper feed mechanism for a printer device, wherein the drawer is provided with a second guide member for taking in the printing paper conveyed along the guide surface. 2. The first and second guide members are pinch rollers arranged in a plurality in the axial direction by being pressed against the respective feed rollers, and the first and second guide members are arranged on the upstream side. The printing paper is displaced in the outer peripheral direction so as to be pressed against the guide surface, and the downstream
2. The printer according to claim 1, wherein the printing paper is shifted in an outer peripheral direction so as to take in the printing paper conveyed along the guide surface.
A paper feed mechanism of the printer device according to the above. 3. A pinch roller disposed on the outer periphery of the upstream feed roller, the pinch roller having the largest step relative to the guide surface is fixed, and is disposed toward the guide surface. 3. The paper feed mechanism according to claim 2, wherein the pinch roller is freely movable toward and away from the feed roller surface. 4. The paper feed mechanism according to claim 3, wherein said fixed pinch roller is rotatably provided on a first roller holder fixed to a frame of said printer. 5. A pinch roller which is freely contactable and detachable is rotatably supported by an adjacent first roller holder.
And a biasing member provided at the rear end of the second roller holder so that the pinch roller follows the roller surface of the feed roller. A paper feed mechanism of the printer device according to the above. 6. The upstream member according to claim 6, wherein the guide member is provided on the upstream side.
2. The apparatus according to claim 1, further comprising a shaft holding portion for holding a shaft of the drawer, supported by an urging member, and maintaining a constant relationship between the guide surface and a roller surface of the feeder. Paper feed mechanism of printer device. 7. A roller holder fixed to a frame of the printer device by rotatably supporting a pinch roller against which each feeder is pressed, the first and second guide members. 2. A paper feed mechanism according to claim 1, wherein said paper feed mechanism is an arc surface provided along an outer circumferential direction of said feeder at an end of said paper feeder.