JPH1111754A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the return of a leading part of roll paper when reverse force to a conveying direction acts upon the leading part. SOLUTION: Pinch rollers 16, 17 formed by fitting a plurality of rollers 19, 21 to rotary shafts 18, 20 are arranged in proximity so that the rollers 19, 21 are alternately positioned and that an imaginary cylindrical face including the outer peripheral surface of the roller 19 intersects an imaginary cylindrical face including the outer peripheral surface of the roller 21, and the pinch rollers 16, 17 are brought into pressure contact with a carrier roller 7. With a plurality of pinch rollers 16, 17 thus brought into pressure contact with the carrier roller 7, a leading part 3a of roll paper is brought into surface contact to heighten holding force of the leading part 3a, and this pressure contact with the carrier roller 7 in the intersecting state of the imaginary cylindrical faces including the outer surface of the rollers 19, 21 prevents the tip of the leading part 3a from entering between the pinch roller 16 and pinch roller 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for printing on roll paper supported by a roll paper holder.

[0002]

2. Description of the Related Art Some conventional printers have a transport roller for feeding paper to a printing section. A pinch roller is pressed against the transport roller, and the paper is fed between the transport roller and the pinch roller. When roll paper is used, the roll paper is rotatably supported by the roll paper holder. When printing is performed on roll paper, the roll paper is rotated by being pulled out by a transport roller and a pinch roller. Here, when there is a difference between the inner diameter of the roll paper and the outer diameter of the roll paper holder, when the roll paper is pulled out, the roll paper swings around the roll paper holder in a direction approaching and separating from the printing unit. . When the roll paper swings in a direction away from the printing unit, the drawn-out portion of the roll paper being fed by the transport roller and the pinch roller is pulled in a direction opposite to the transport direction. At this time, if the holding force of the transport roller is weak, the drawn-out portion of the roll paper will be pulled back in the reverse direction of the transport direction.At this time, if printing is being performed, the paper will not be transported normally, Printing is adversely affected.

As a first example of a conventional printer for preventing such a return of a roll paper drawer, a plurality of rollers are provided between a roll paper holder and a printing unit, and a roll paper transport path is provided. In some cases, the roll paper is bent in a zigzag direction in a direction perpendicular to the width direction of the paper to apply tension to the roll paper draw-out portion so that the roll paper draw-out portion does not return even if the roll paper swings.

Next, a second example of a conventional printer for preventing return of a roll paper drawer will be described with reference to FIG. FIG. 3 is a vertical right side view schematically showing the structure of the conventional printer 1, and the left side in FIG.
It is the front side of. First, the printer 1 has a roll paper holder 2 at the rear, a roll paper 3 is rotatably supported by the roll paper holder 2, and a printer 6 having a thermal head 4 and a platen 5 at the front. doing. Behind the printing unit 6, there is provided a transport roller 7 for feeding the drawn-out portion 3 a of the roll paper 3 to the printing unit 6, and a pinch roller 8 is pressed against the transport roller 7.

[0005] One end of a substantially L-shaped damper 9 is attached to the roll paper holder 2, and one side 10 of the damper 9 is close to the end of the roll paper 3 along the radial direction of the roll 3 paper. The other side 11 is parallel to the rotation axis of the roll paper 3.

In such a structure, when the swinging roll paper 3 rotates in the reverse direction of the transport direction, the damper 9 reduces the force acting on the drawer 3a in the reverse direction of the transport direction. .

Next, a third example of a conventional printer will be described with reference to FIG. FIG. 4 is a vertical right side view schematically illustrating the structure of the printer 12, and the left side in FIG. 4 is the front side of the printer 12. The same parts as those in the second conventional example are denoted by the same reference numerals, and description thereof is omitted. In the third example, two pinch rollers 13 are pressed against the transport roller 7 and a belt 14 is stretched over the pinch roller 13.

In such a structure, the drawer portion 3a is pressed against the transport roller 7 by the two pinch rollers 13 to bring the transport roller 7 into contact with the drawer portion 3a, thereby increasing the contact area. . If the contact area is large, the force for holding the drawer portion 3a increases, so that even if a force in the reverse direction of the transport direction acts on the drawer portion 3a, no slip occurs between the transport roller 7 and the drawer portion 3a. .

The reason why the belt 14 is stretched over the pinch roller 13 is to prevent the leading end of the drawer 3a from entering between the two pinch rollers 13. In the case where the roll paper 3 is a label roll in which a label is attached to a mount, the contact surface between the mount and the transport roller 7 is cylindrical. The label may be peeled off between them.

[0010] In the above description and the following description, the fact that the roll paper is pulled back means that the roll paper is actually pulled back and that the roll paper conveyance speed changes instantaneously. included.

[0011]

In the printer of the first conventional example, since the transport path of the roll paper is formed in a zigzag manner, a portion where the roll paper is drawn out to the printing section becomes long. Further, it is not easy to set the roll paper according to the zigzag transport path.

In the printer 1 of the second conventional example as shown in FIG. 3, since the damper 9 is used, the number of parts increases and the cost increases. Further, since the drawer portion 3a is hung on the damper 9, the transport path is longer than that of the printer of the first conventional example.

In the printer 12 of the third conventional example as shown in FIG. 4, there is no problem that the transport path is long because the transport path is straight, but the number of parts increases because the belt 14 is used. , Increase costs.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent a roll paper from returning from a drawn portion without lengthening a conveyance path.

[0015]

According to a first aspect of the present invention, there is provided a printer according to the present invention, wherein a roll paper supported by the roll paper holder is rotated by a driving roller provided between the roll paper holder and the printing unit. In a printer that conveys a plurality of rollers, a plurality of pinch rollers, which are mounted in series on a rotating shaft with a gap therebetween, are arranged in close proximity in parallel to each other and press-contact each of the conveying rollers. The virtual cylindrical surface including the outer peripheral surface intersects the virtual cylindrical surface including the outer peripheral surface of the adjacent pinch roller.

Therefore, the drawer of the roll paper is
Since the pinch roller presses the transfer roller against the transfer roller and makes surface contact with the transfer roller, the holding force increases, and the slide between the transfer roller and the drawer portion hardly occurs. , The drawer portion is difficult to return.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a printer according to the present invention will be described with reference to FIGS. FIG.
FIG. 2 is a vertical right side view of the printer according to the embodiment, and FIG.
FIG. 3 is a plan view of a transport roller and a pinch roller. The same parts as those shown in the conventional example are denoted by the same reference numerals,
Description is also omitted.

In the printer 15 of this embodiment, pinch rollers 16 and 17 are pressed against the transport roller 7.
The pinch roller 16 includes a plurality of rollers 19 on a rotating shaft 18.
Is attached. Adjacent rollers 19
Is longer than the axial length b of the roller 19.
Similarly, the pinch roller 17 has a plurality of rollers 21 attached to a rotating shaft 20. Roller 19
And the roller 21 have the same shape and material, the length of the roller 21 in the axial direction is b, and the interval between the adjacent rollers 21 is a.

The roller 19 is located between the adjacent rollers 21 and is close to the rotating shaft 20. The roller 21
Are located between the adjacent rollers 19 and are close to the rotating shaft 18. That is, the rollers 19 and the rollers 21 are positioned alternately, and the virtual cylindrical surface including the outer peripheral surface of the roller 19 and the virtual cylindrical surface including the outer peripheral surface of the roller 21 intersect.
The pinch roller 16 and the pinch roller 17 are arranged close to each other and are in pressure contact with the transport roller 7.

Since the rotating shaft 18 and the rotating shaft 20 are each urged by a spring (not shown), the pinch roller 16 and the pinch roller 17 are in pressure contact with the transport roller 7, respectively. It can be transported at any thickness.

The transport roller 7 and the pinch rollers 16,
The roll paper holder 2 is provided at the same height as the contact height with the roll 17, that is, on the virtual extension line of the transport path, and can correspond to two drawing directions of the roll paper indicated by the solid line and the dotted line in FIG.

In such a configuration, the drawn-out portion 3a of the roll paper 3 includes the transport roller 7 and the pinch rollers 16,
17 and is conveyed to the printing unit 6 by the rotation of the conveying roller 7. Since the drawer portion 3a and the transport roller 7 are in surface contact with a cylindrical surface along the outer peripheral surface of the transport roller 7 between the pinch roller 16 and the pinch roller 17, the holding force of the drawer portion 3a is large. Therefore, when the roll paper 3 is pulled out, as shown by the two-dot chain line in FIG. 1, even if the roll paper 3 swings around the roll paper holder 2 and a force in the reverse direction of the transport direction is applied to the drawer portion 3a,
The drawer portion 3a is not pulled back. Therefore, the drawer portion 3a printed by the printing unit 4 does not come back in the reverse direction of the transport direction, so that printing is not adversely affected, and high quality printing is obtained. In the present embodiment, the pinch rollers 16 and 17
Only because it does not require other parts,
Parts cost can be reduced.

[0023]

In the printer according to the first aspect of the present invention, since a plurality of pinch rollers having a plurality of rollers are in pressure contact with the transport roller, the drawn portion of the roll paper is pressed against the transport roller by the plurality of pinch rollers. Because the transport roller and the roll paper drawer are in surface contact,
The force for holding the drawer portion is increased, and normal conveyance can be performed even if a force in the reverse direction of the conveyance direction is applied to the drawer portion. In addition, the adjacent pinch rollers are arranged close to each other so that the virtual rollers including the outer peripheral surface of each roller intersect and intersect with each other and press against the conveying roller. It is possible to prevent the label paper from entering between the pinch rollers and, when the roll paper is a label roll, to prevent the label from peeling off from the backing paper between the pinch rollers.

[Brief description of the drawings]

FIG. 1 is a vertical sectional right side view showing an embodiment of a printer of the present invention.

FIG. 2A is a vertical right side view of a conveying roller and a pinch roller, and FIG. 2B is a plan view.

FIG. 3 is a vertical sectional right side view showing a second example of the conventional printer.

FIG. 4 is a right side view in vertical section showing a third example of a conventional printer.

[Explanation of symbols]

 2 Roll paper holder 3 Roll paper 6 Printing unit 7 Conveyance roller 15 Printer 16, 17 Pinch roller 18, 20 Rotary shaft 19, 21 Roller

Claims (1)

[Claims] In a printer for transporting roll paper supported by the roll paper holder to the printing unit by rotating a transport roller provided between the roll paper holder and the printing unit, a plurality of rollers are spaced apart from each other. A plurality of pinch rollers attached to the same rotating shaft are arranged in parallel in close proximity to each other and pressed against the transport roller, respectively, and a virtual cylindrical surface including an outer peripheral surface of each of the plurality of rollers attached to one pinch roller. The printer intersects a virtual cylindrical surface including an outer peripheral surface of each of the plurality of rollers attached to the adjacent pinch rollers.