JP2003212405A - Paper conveyance device for printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out accurate and stable paper conveyance even when a reverse conveyance action is applied in paper conveyance, and provide stability in printing position accuracy and improvement in printing quality. <P>SOLUTION: The printer has a first paper conveying means 15a and a second paper conveying means 15b composed so as to allow normal and reverse conveyance with a printing part 5 in between. The first and second paper conveying means 15a and 15b comprise paper conveying rollers 13a and 13b respectively driven by a conveyance motor, and pinch rollers 14a and 14b provided so as to press against the paper conveying rollers. When rotation of the paper conveying rollers 13a and 13b is for normal paper conveyance, the pinch roller 14a of the first paper conveying means 15a is used as a biting side against the paper conveying roller 13a, and the pinch roller 14b of the second paper conveying means 15b is used as a releasing side against the paper conveying roller 13b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper transporting device for a printer that prints predetermined information on a label that is detachably temporarily attached to a strip-shaped backing of paper wound in a roll shape. The present invention relates to a paper transporting device of a printer configured to be capable of forward and reverse transport on a transporting path, which stably transports a paper and has high printing position accuracy.

[0002]

2. Description of the Related Art As shown in FIG. 2, in a conventional paper transporting device for a heat-sensitive printer that prints on a heat-sensitive color-developing label, a plurality of labels 101 are temporarily attached at equal intervals in a printer having a peeling function. A sheet 103 including a strip-shaped mount 102, a printing unit 105 that prints on the label 101, and a peeling mechanism 106 that peels the label 101 from the strip-shaped mount 102 as the sheet 103 is conveyed.
And a drive mechanism (not shown) for carrying and stopping the paper 103 is known. Reference numeral 107 is a label sensor for detecting the label 101 in a state of being protruded from the peeling mechanism 106, reference numeral 108 is a thermal head constituting the printing unit 105, and reference numeral 109 is the label 101 for peeling the label 101. It is a winding shaft that winds up the strip-shaped mount 102 after being formed.

In such a printer,
While the paper 103 is being conveyed, printing is performed by the printing unit 105 on the label 101 that is temporarily attached to the strip-shaped mount 102, and the printed label 101 is conveyed to the peeling mechanism 106. By folding the strip-shaped backing sheet 102 back in the direction away from the label 101, the label 101 is peeled off sequentially from the front side in the conveying direction, and the label 101 is peeled off to its end (the rear end in the conveying direction). At this time, the label 10 is stopped by stopping the conveyance of the strip-shaped mount 102.
1 is held in a standby state in which it projects from the strip-shaped mount 102. Here, another label 101 positioned behind the label 101 conveyed to the standby position passes through the printing unit 105, but at this time, the label 101 is not printed.

When the worker removes the printed label 101 in the standby state, the removal of the label 101 is detected by the label sensor 107, and the drive mechanism is reversed based on the detection signal. By being driven, the paper 103 is conveyed in the opposite direction,
The next label 101 is returned to the print position, printing is performed on the label 101 as described above, and further, the label 101 is peeled to the end portion and put in a standby state.

[0005]

By the way, the following problems to be improved remain in such a conventional paper transporting device of a printer having a peeling function. That is, the label 101 that has finished printing is peeled off to the end and is temporarily held in a standby state. In this state, a part of the next label 101 has passed through the printing unit 105 without printing. Waiting for a state. this is,
This is because, in order to increase the number of labels 101 to be accommodated in the strip-shaped mount 102, the temporary attachment pitch of the labels 101 needs to be narrowed as much as possible. Then, after the printed label 101 at the standby position is removed, the next label 10
1 is printed, but for this purpose, label 1
01 must be once returned to the printing position of the printing unit 105.

A conventional paper transporting device for a printer having a peeling function includes a platen roller 110 and a thermal head 10.
The sheet 103 is sandwiched between the sheets 8, and the sheet 103 is conveyed in the forward and backward conveying directions by the rotational driving of the platen roller 110 and the frictional force generated between the sheet 103. Then, at the time of carrying in the forward carrying direction, a force acts on the tip of the thermal head 108 in the direction of arrow A (toward the platen roller 110 on the escape side) about the rotation fulcrum 112 of the support arm 111 supporting the thermal head 108, and When the paper 103 is transported in the reverse transport direction, the tip of the thermal head 108 is centered on the rotation fulcrum 112 of the support arm 111 that supports the thermal head 108 in the direction of arrow B (the platen roller 110).
On the other hand, a force is applied to the bite side), which causes a difference in the conveyance load resistance between the normal conveyance direction and the reverse conveyance direction.

The roll paper 1 around which the paper 103 is wound
No. 04 has a large diameter at the beginning of use, and has a smaller diameter as it is used, so that the weight of the roll paper 104 changes to a lighter weight, and slack occurs on the paper supply side of the printing unit each time the paper 103 is conveyed forward or backward. As a result, the load variation is applied to the drive unit of the platen roller 110 that controls the sheet conveyance, and slippage occurs between the platen roller 110 and the sheet 103. As a result, the amount of forward conveyance and the amount of reverse conveyance of the sheet 103 are different, the printing is not performed at the position where the label 101 should originally be printed, and printing misalignment occurs, causing a problem in printing position accuracy.

The present invention has been made in view of the above-mentioned conventional problems, and in the paper transportation of a label printer, accurate and stable paper transportation can be performed even if a reverse transportation operation is added, and printing position accuracy is improved. The purpose is to achieve stability and improvement of print quality.

[0009]

In order to achieve the above object, the paper transporting device of a printer according to claim 1 is a first paper transporting device configured to be capable of forward and reverse transporting with a printing unit interposed therebetween. And in a printer having a second sheet conveying means,
The first paper transporting means and the second paper transporting means are composed of a paper transporting roller driven by a transporting motor and respective pinch rollers provided so as to be in pressure contact with the paper transporting roller. The pinch roller of the first sheet conveying means is on the biting side with respect to the sheet conveying roller, and the pinch roller of the second sheet conveying means is on the escape side with respect to the sheet conveying roller when the sheet is normally conveyed. It is characterized by being provided.

According to a second aspect of the present invention, there is provided a paper transport device for a printer, wherein the first paper transport means and the second paper transport means are:
It is characterized in that it is symmetrically arranged with respect to the center vertical line of the paper transport roller.

According to a third aspect of the present invention, there is provided a paper transporting device for a printer, in which the pinch roller and the paper transporting roller are in pressure contact with each other, with respect to the straight line connecting the center of the lever shaft and the center of the pinch roller, the center of the pinch roller and the paper. It is characterized in that the angle formed by the straight line connecting the centers of the transport rollers is set to be an obtuse angle.

[0012]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to FIG. A paper transporting device of a printer having a peeling function includes a printing unit 5 that prints on a label 1 of a paper 3 that is composed of a label 1 that is temporarily attached to a band-shaped backing sheet 2 at equal intervals, and the paper 3. Is provided with a peeling mechanism 6 for peeling the label 1 from the strip-shaped backing sheet 2 and a transport motor 21 for transporting the paper 3 and stopping it. When the sheet is peeled from the strip-shaped backing sheet 2 up to the end thereof, the conveyance of the sheet 3 is stopped, so that the label 1 is held in a standby state protruding from the strip-shaped backing sheet 2,
The operator removes the printed label 1 from the strip mount 2,
It can be attached to any place. When the label 1 is removed from the strip-shaped backing sheet 2, the label sensor 7 detects that the label 1 is removed, and the transport motor 21 is reversely driven based on the detection signal.
As described above, by conveying the paper 3 in the reverse direction,
The basic configuration is that the next label 1 is returned to the print position.

In FIG. 1, a pair of plate-shaped roll paper support guides 11 for supporting a roll paper 4 formed by winding a paper 3 having a label 1 temporarily attached to a strip-shaped backing paper 2 in a roll shape.
And two paper transport rollers 13a, 13b and pinch rollers 14a, 14b arranged on the transport path 12 for transporting the paper 3, and the printing unit 5 faces the thermal head 8 and the thermal head 8 and prints. At the same time, it is constituted by a thermal head 8 and a platen roller 10 which sandwiches the paper 3 therebetween. Further, the peeling mechanism 6 has a wedge-shaped cross-section, and is designed to fold back the strip-shaped backing sheet 2 guided on the upper surface at the apex angle portion and guide it in the opposite direction. A winding shaft 9 is provided below the peeling mechanism 6 and at a rear position in the transport direction of the strip-shaped mount 2 to wind up the strip-shaped mount 2 from which the label 1 is peeled by the peeling mechanism 6. Here, the pinch for sandwiching the paper 3 between the paper transport rollers 13a and 13b for transporting the paper 3 and the paper transport rollers 13a and 13b is arranged so as to face the paper transport rollers 13a and 13b. The rollers 14a and 14b are provided, and the paper feeding roller 13b is provided on the paper supply side near the printing unit 5.
And a pinch roller 14b are arranged, and the paper transport roller 13a and the pinch roller 14a are provided on the peeling mechanism side near the printing unit 5.
Are arranged.

Further, a group of gears rotated by the transport motor 21 or a timing belt transmits the sheet 3 to the sheet transport rollers 13a and 13b, and the sheet transport roller 13a and the sheet transport rollers 13b transfer the sheet 3 to the sheet.
The sheet 3 is conveyed by the pinch rollers 14a and 14b that sandwich the sheet. Further, the platen roller 10 does not serve as a driving roller for conveying the sheet, but functions as a roller for printing, and is rotated by the pressing of the thermal head 8 as the sheet 3 is conveyed.

Next, the schematic construction of the first sheet conveying means 15a composed of the conveying roller 13a and the pinch roller 14a and the second sheet conveying means 15b composed of the conveying roller 13b and the pinch roller 14b will be described with reference to FIG. .

The first sheet conveying means 15a and the second sheet conveying means 15b are, as shown in FIG.
The central portions of a and 14b are lever shafts 16a and 16b, respectively.
Pinch roller lever 17 rotatably attached by
The shafts 18a and 18b are rotatably attached to the respective ends of a and 17b. Further, at the other ends of the pinch roller levers 17a and 17b, there are suspended pinch rollers 14a and 14b and pressing springs 19a and 19b for press contact with the sheet conveying rollers 13a and 13b.
The pinch roller 14a is pressed against the center vertical line of the transfer roller shaft 20a of the paper transfer roller 13a from the left side, and the pinch roller 14b is pressed against the center vertical line of the transfer roller shaft 20b of the paper transfer roller 13b from the right side. Lever shaft 1 which is a fulcrum of rotation of the pinch roller levers 17a and 17b
Centers of 6a and 16b and respective pinch rollers 14
The angle β formed by the center of the pinch rollers 14a, 14b and the line M connecting the centers of the respective paper transport rollers 13a, 13b with respect to the straight line L connecting the centers of a and 14b is set to be an obtuse angle. ing.

The pinch roller levers 17a and 17b are pinch rollers 14 to the sheet conveying rollers 13a and 13b which are rotatably supported by lever shafts 16a and 16b, respectively.
The pinch roller levers 17a and 17b are operated by a link mechanism (not shown) which is a pressing mechanism of a and 14b and which is linked to a mechanism for contacting and separating the thermal head 8 with respect to the platen roller 10, and the pinch rollers 14a and 14b convey the paper. Roller 13
It is possible to contact and separate from a and 13b.

With this structure, the pinch roller 14a rotates in the biting direction and the pinch roller 14b rotates in the escape direction with respect to the rotation of the sheet conveying rollers 13a and 13b in the direction of arrow C, and the pinch roller 1 rotates.
4a is rotated with almost no slippage with respect to the sheet conveying roller 13a, and the pinch roller 14b is rotated with almost constant slippage with respect to the sheet conveying roller 13b. The means 15a serves as a main carrying roller, and the second paper carrying means 15b serves as a subsidiary carrying roller. Further, when the sheet 3 is conveyed in the reverse direction, the roles thereof are reversed, and the second sheet conveying means 15a becomes the main conveying roller and the first sheet conveying means 15a becomes the sub-conveying roller, and the normal conveying amount and the reverse conveying amount are substantially the same. This is the transport amount, and after the label 1 is peeled off, the printing accuracy at the next designated printing position on the label 1 is improved. Further, when the paper 3 is initially mounted in the printer, even if the paper 3 is loosely set between the first paper conveying means 15a and the second paper conveying means 15b, the slack is removed as the paper is conveyed and Problems such as jam and meandering are solved.

The pressure contact and separation mechanism of the thermal head 108 with respect to the platen roller 110 relating to the printing unit 105 of FIG. 2 includes a support arm 11 for supporting the thermal head 108.
Generally, a structure is used in which the rotation pressing point 112 of FIG.
As shown in (4), a pressure contact and separation structure by vertical movement is preferable.

Although the above-mentioned printing method has been described as a heat-sensitive method in which a label uses a heat-sensitive paper, the present invention is not limited to this, and a thermal transfer method using an ink ribbon is also effective.

[0021]

As described above, according to the paper transporting device of the printer of the present invention, since the first transporting means and the second transporting means are provided, it is possible to arrange the printer between the first transporting means and the second transporting means. It is possible to reliably prevent the occurrence of slack in the paper, and in a printer equipped with a peeling device, the amount of movement of the paper in the forward and reverse directions is approximately the same, so the printed label is peeled by the peeling mechanism. However, the conveyance accuracy when the label positioned in the latter stage is conveyed to the designated print position in the reverse direction is improved, which leads to the improvement of the print position accuracy and the print quality. Furthermore, by providing a multi-color ribbon loading mechanism, it is possible to achieve high-quality printing without color misregistration even in a color printer that performs color printing by transporting paper in the reverse direction.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

FIG. 2 is a schematic side view showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 label 12 conveyance path 2 strip | belt mount 13a, 13b paper conveyance roller 3 paper 14a, 14b pinch roller 4 roll paper 15a 1st paper conveyance means 5 printing part 15b 2nd paper conveyance means 6 peeling mechanism 16a, 16b lever shaft ( 7) Label sensor 17a, 17b Pinch roller lever 8 Thermal head 18a, 18b Shaft 9 Winding shaft 19a, 19b Pressing spring 10 Platen roller 20a, 20b Conveying roller shaft 11 Roll paper support guide 21 Conveying motor

Claims (3)

[Claims] Claim: What is claimed is: 1. A tapping machine having a first paper transporting means and a second paper transporting means configured to be capable of forward and reverse transporting with a printing unit interposed therebetween, wherein the first paper transporting means and the second paper transporting means are provided. The paper carrying means is composed of a paper carrying roller driven by a carrying motor and pinch rollers provided so as to be in pressure contact with the paper carrying roller. It is characterized in that the pinch roller of the first sheet conveying means is provided on the bite side with respect to the sheet conveying roller, and the pinch roller of the second sheet conveying means is on the escape side with respect to the sheet conveying roller. Paper transport device for printer. 2. The paper carrying device for a printer according to claim 1, wherein the first paper carrying means and the second paper carrying means are symmetrically arranged with respect to a center vertical line of the paper carrying roller. 3. A straight line connecting the center of the pinch roller and the center of the lever shaft, which is the pivotal fulcrum of the pinch roller lever pivotally supported at its tip, when the pinch roller and the sheet conveying roller are in pressure contact with each other. 3. The paper transporting device for a printer according to claim 1, wherein the angle formed by the center of the pinch roller and the straight line connecting the centers of the paper transporting rollers is set to be an obtuse angle.