JPH10139239A - Label printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prohibit causing of label peeling by eliminating looseness of paper. SOLUTION: A carrier roller 12 in the downstream of the carrier direction out of the two carrier rollers 11, 12 of a roll paper carrier device 1 on which a roll paper 13 is placed is rotated faster than the carrier roller 11 in the upstream of the carrier direction at the time of carrying the roll paper 13, and the carrier roller 11 in the upstream is rotated faster than the carrier roller 12 in the downstream at the time of rewinding the roll paper 13. Consequently, a speed difference is formed between the two carrier rollers 11, 12, and paper carriage is carried out while constantly giving tension to the roll paper 13 between the two carrier rollers 11, 12 by this speed difference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a label printer having a roll paper transport device for transporting roll paper to a printing section and rewinding the roll paper from the printing section, and more particularly to a structure of a transport roller of the roll paper transport apparatus. .

[0002]

2. Description of the Related Art In a conventional label printer, roll paper is placed on two transport rollers arranged side by side, and the transport of the roll paper to a printing unit and the printing unit are performed by forward and reverse rotation of the two transport rollers. There is a device provided with a roll paper transport device configured to perform rewinding from a roll.

FIG. 5 is a diagram showing a drive system of a roll label paper transporting device which is an example of such a conventional roll paper transporting device. A predetermined driving force obtained by a motor and a speed reduction mechanism (not shown) is driven. The driving force is transmitted to the pulley 103, and the driving force of the driving pulley 103 has the same number of teeth via the driving belt 14a, and the first and second driven pulleys 101 and 102 which together with the driving pulley 103 constitute the roll label paper driving system 14. It is transmitted to.

[0006] As shown in FIG. 6, the rotation shafts 101 a, 1 of these first and second driven pulleys 101, 102 are provided.
The first and second transport rollers 11, 12 are fixed to the second transport roller 11, 02a.
Reference numeral 12 is driven by the driving force of the driving pulley 103 transmitted through the first and second driven pulleys 101 and 102, and conveys the roll label paper 13 to the printing unit.

Here, the roll label paper drive system 14
Rotates the first and second transport rollers 11 and 12 in the direction of transporting the roll label paper 13 to the printing unit of the printer body during a normal job (printing operation). The paper 13 is rotated in the direction of rewinding from the printing unit.

Hereinafter, the operation of transporting the roll label paper 13 to the printing section of the printer main body is referred to as feed, and the operation of rewinding from the printing section is referred to as backfeed. In FIG. 5, arrow a indicates the rotation direction of the first and second transport rollers 11 and 12 during feeding, and arrow b indicates the rotation direction during back feeding.

The first and second teeth having the same number of teeth are theoretically the same.
First and second driven by pulleys 101 and 102
If the outer diameters of the transport rollers 11 and 12 are the same, assuming that the linear velocity of the first transport roller 11 is V ₁₁ and the linear velocity of the second transport roller 12 is V ₁₂ , V ₁₁ = V _{12 and the} transport amount is also large. Matches.

However, in practice, the outer diameters of the first and second transport rollers 11 and 12 may be different due to errors in the production of the transport rollers, and in this case, for example, V ₁₂ <V _11. Sometimes. Then, as described above, the first transport roller 1
The linear velocity V ₁₁ of the first transport roller 12 is the linear velocity V ₁₂ of the second transport roller _12.
Roll label paper 1
3, the first and second transport rollers 11, 1
5, the roll paper 13 is loosened 104 due to the speed difference as shown in FIG.

[0009] Therefore, conventionally, in order to prevent such a phenomenon, by increasing the outside diameter [Phi ₂ of the second conveying roller 12 than the outer diameter [Phi ₁ of the first conveying roller 11, for example, [Phi ₂ to 16 .2Mm, by setting the [Phi ₁ 16.0 mm, towards the linear velocity V ₁₂ of the second conveying roller 12 is set to be greater than the linear velocity V ₁₁ of the first conveying roller 11.

[0010] Then, in this manner by increasing the linear velocity V ₁₂ of the second conveying roller 12, second conveying roller 1
2 transports the roll label paper 13 while pulling it with an appropriate force, thereby preventing the looseness 104 of the roll paper 13 from being generated.

When the printing of one job is completed, the next printing paper positioned at the exit of the printing section is back-fed to the entrance. Thereafter, when a sensor (not shown) detects the back-fed paper, the next roll label paper is used. The drive system 14 is driven in the back-feed direction, whereby the back-fed paper is rewound.

[0012]

However, such a conventional label printer has the following disadvantages because priority is given to operation guarantee during feeding. That is, the outer diameters Φ ₂ , Φ of the first and second transport rollers 11, 12
_{If 2} is set so that V ₁₂ <V ₁₁ when feeding,
At the time of the back feed, V ₁₁ <V ₁₂ on the contrary, and the roll label paper 13 is loosened between the first and second transport rollers 11 and 12 (see FIG. 5).

Here, if the number of printed sheets at the time of feed after the back feed is sufficient, the slack is gradually eliminated and finally eliminated due to the linear velocity relationship of V ₁₂ > V ₁₁ . However, there are various market needs and usage forms of the label printer, and there is a case where printing of several tens to several hundreds is performed as one job, and a printing of a small number (five or less) and many (image) types is required. .

In the case of such a small number of jobs, the slack of the paper caused by the back feed cannot be completely absorbed by the next feed, and the slack of the paper becomes the first and the second with the increase of the frequency of the back feed. There is a problem that the toner is accumulated between the second transport rollers 11 and 12, thereby causing paper breakage and label peeling.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a label printer which can prevent the label from coming off by eliminating the looseness of the paper. It is intended for.

[0016]

SUMMARY OF THE INVENTION The present invention provides two side-by-side
A label provided with a roll paper transport device for placing roll paper on one transport roller and transporting the roll paper to a printing unit and rewinding the roll paper from the printing unit by forward and reverse rotation of the two transport rollers In the printer, when the roll paper is transported, the transport roller on the downstream side in the transport direction of the two transport rollers of the roll paper transport device is rotated faster than the transport roller on the upstream side in the transport direction, and the roll paper is rewound. Sometimes, the upstream conveying roller is rotated faster than the downstream conveying roller to form a speed difference between the two conveying rollers.

According to the present invention, a one-way clutch is provided on one of the two transport rollers, and the one transport roller is placed when the one-way clutch is unlocked. It is characterized in that a speed difference is formed between the two transport rollers so that the two transport rollers rotate with the other transport roller via the roll paper.

Further, according to the present invention, the two transport rollers are independently driven, and the two transport rollers are provided with one-way clutches having different lock directions, respectively, and the transport rollers on the downstream side are transported when the roll paper is transported. Only the one-way clutch is locked, and at the time of rewinding of the roll paper, only the one-way clutch of the upstream transport roller is locked so that one of the transport rollers passes through the roll paper placed above. A speed difference is formed between the two transport rollers so that the two transport rollers rotate together.

Further, as in the present invention, when the roll paper is transported, the transport roller on the downstream side in the transport direction of the two transport rollers of the roll paper transport device on which the roll paper is placed is moved from the transport roller on the upstream side in the transport direction. When the roll paper is rewound, a speed difference is formed between the two transport rollers by rotating the upstream transport roller faster than the downstream transport roller. The paper is transported while always applying tension to the roll paper between the transport rollers.

Further, as in the present invention, a one-way clutch is provided on one of the two conveying rollers, and the roll paper on which one of the conveying rollers is mounted when the one-way clutch is unlocked. A speed difference is formed in such a way as to be rotated by the other conveying roller via the, and the speed difference causes the paper to be conveyed while always giving tension to the roll paper between the two conveying rollers by the speed difference.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of a label printer according to a first embodiment of the present invention. In the same figure, the same reference numerals as those in FIG. 5 indicate the same or corresponding parts.

In FIG. 1, reference numeral A denotes a label printer, and the label printer A is a roll label paper transport device 1.
And a printer body A1 including a transport device 2, a printing device 3 as a printing unit, and the like.

Here, the roll label paper transport device 1 has first and second transport rollers 11 and 12 arranged horizontally side by side, and is placed on the first and second transport rollers 11 and 12. The roll label paper 13 is placed thereon. The driving force is transmitted to the first and second transport rollers 11 and 12 by a motor, a speed reduction mechanism and a roll label paper drive system 14 (not shown), and the weight of the roll label paper 13 and the first and second transport rollers 11 and 12 are transmitted. A rotational force is obtained by friction with the surface of the roll label paper 13, and the outermost periphery of the roll label paper 13 is separated by the rotational force. In addition,
Thereafter, the outermost roll label paper 13 is transported to the label paper transport device 2 while forming a loop.

Incidentally, of the first and second transport rollers 11 and 12, the second transport roller 12 located on the downstream side is a rotating shaft 102a of the second driven pulley 102.
(See FIG. 6) with the one-way clutch 105 shown in FIG. 2 interposed. Here, the locking direction of the one-way clutch 105 is the rotation direction of the feed indicated by the arrow a.

In the present embodiment, as described above, the outer diameter Φ ₂ of the second transport roller 12 is
1 is larger than the outer diameter Φ ₁ , so that V ₁₂ > V ₁₁ at the time of feeding.

Therefore, at the time of feeding, the one-way clutch 105 is locked, whereby the driving force of the second driven pulley 102 is transmitted to the second transport roller 12, and the second transport roller 12 moves in exactly the same manner as in the conventional system. The paper 13 is conveyed while being pulled, that is, while giving tension to the roll label paper 13. At this time, the first transport roller 11 rotates while maintaining the relationship of V ₁₁ <V ₁₂ .

On the other hand, at the time of back feed, the one-way clutch 105 is not locked, so that the driving force of the second driven pulley 102 is not transmitted to the second transport roller 12. Therefore, only the first transport roller 11 is driven,
The second transport roller 12 is rotated by its own weight of the roll label paper 13 transported by the first transport roller 11.

Then, as the second transport roller 12 rotates in this manner, the first and second transport rollers 1 are rotated.
The speed relationship between 1 and 12 is V ₁₁ > V ₁₂ , whereby the first transport roller 11 feeds the roll label paper 13, that is, feeds the roll label paper 13 back while feeding it.

In FIG. 1, reference numeral 15 denotes a loop sensor which is disposed on a transport path (not shown) of the roll label paper 13 and rotates around a rotating shaft 16; 17, a skew feeding roller; and 18, a skew feeding roller. This is an oblique feeding roller that presses the roller 17 from above. And the roll label paper 13 is
The sheet is fed to the label sheet transport device 2 while being in contact with the upper surface of the loop sensor 15 and while being sandwiched between the two skew feeding rollers 17 and the skew rollers 18.

The rotation angle of the loop sensor 15 changes in accordance with the tension of the roll label paper 13 that is in contact with the loop sensor 15, and during feeding, the tension of the roll label paper 13 increases, and the loop sensor 15 falls below a predetermined loop. When the rotation angle indicates that the operation has been completed, a detection signal is output to the control device 40 provided in the label printer A. Further, at the time of back feed, when the roll label paper 13 becomes slack and the rotation angle reaches a predetermined loop or more, a detection signal is output to the control device 40. Further, the control device 40 is configured to drive the roll label paper transport device 1 in the feed and back feed directions based on the detection signal.

On the other hand, the skew feeding roller 18 is attached to a pressure plate 19, and the pressure plate 19 is moved by a solenoid (not shown) in a direction to hold down the roll label paper 13 at the time of feeding, so that the roll label paper 13 is inclined. While the line is prevented, it is retracted upward at the time of back feed.

Next, the transport device 2 and the printing device 3 of the printer main unit A1 will be described.

First, as shown in FIG. 1, the transport device 2 includes a synchro pulley 21 and a belt 22 capable of high-precision position control.
A drive roller 23 having the same linear speed as the belt speed is disposed at the entrance of the transport unit 2A composed of the roller unit. The roll label paper 13 sent from the roll label paper transport device 1 is driven by the drive roller 23 and The sheet is conveyed to the printer main body A1 by the provided pinch roller 24, and further to the printing device 3 by the belt conveying unit 2A.

On the other hand, in the case of the present embodiment, the printing apparatus 3 employs an ink jet system as a printing system. Here, this ink jet system is excellent in quietness because it does not contact the print medium,
Advantages include high printing speed, high-density printing, easy colorization, and a compact device.

The printing device 3 includes black, cyan, magenta, and yellow print heads 31, 32, and 3.
3, 34 are arranged. Then, the rotation pulse signal of the stepping motor, which is the driving source of the transport unit 2A (not shown), and the digitized image signal for controlling the ejection of the print heads 31, 32, 33, 34 are synchronized, and the roll label paper 13 is printed. Heads 31, 32, 33, 34
When passing through the printing position by, each color is printed one after another,
An image is formed. Note that the printed roll label paper 13 is sent to a cutting device such as a cutter (not shown) by a paper discharge roller 25 and a paper distribution spur 26 disposed thereon.

Next, the operation of transporting the roll label paper of the roll label paper transport apparatus 1 in this embodiment will be described.

The driving force is transmitted to the driving pulley 103 via the motor and the speed reduction mechanism, and the driving force is transmitted to the first and second driven pulleys 101 and 102 having the same number of teeth. , 12 are driven.

Here, at the time of feeding, when the first and second driven pulleys 101 and 102 rotate in the direction of the arrow a in FIG.
1 is driven, and the one-way clutch 105 whose locking direction is the rotation direction of the feed is locked, whereby the second transport roller 12 is driven via the second driven pulley 102.

Then, the linear velocity V ₁₂ of the second transport roller ₁₂
Who is the greater than the linear velocity V ₁₁ of the first conveying roller 11, second conveying roller 12 while pulling the roll label paper 13 by a suitable force, it conveyed without generating the slack.

On the other hand, when the first and second driven pulleys 101 and 102 rotate in the direction of arrow b during back feed,
Since the one-way clutch 105 is not locked and the driving force of the second driven pulley 102 is not transmitted to the second transport roller 12, only the first transport roller 11 is driven, and the second transport roller 12 The roll label paper 13 conveyed by one conveyance roller 11 is rotated by its own weight.

[0042] Then, in such a case, since the direction of the linear velocity V ₁₁ of the first conveying roller 11 is greater than the linear velocity V ₁₂ of the second conveying roller 12, the words V _11> V _12, The first transport roller 11 feeds back while pulling the roll label paper 13. This solves the problem of looseness of paper that occurs at the time of back feeding in the conventional system and the problem of label peeling due to the looseness.

In the above description, the case where the one-way clutch 105 is provided on the second transport roller 12 has been described. However, the present invention is not limited to this, and the outer diameter Φ ₂ of the second transport roller 12 is When the outer diameter Φ ₁ of the first transport roller 11 is smaller than the outer diameter Φ _1, a one-way clutch whose locking direction is reversed may be provided on the first transport roller 11.

Next, a second embodiment of the present invention will be described.

FIG. 3 is a diagram showing a drive system of the roll label paper transport device according to the present embodiment, and shows the rotating shafts of first and second driven pulleys 101 and 102 of the conventional system (see FIG. 5).
First and second one-way clutches 105a, 105, respectively.
5b, and these one-way clutches 105a,
105b and the first and second transport rollers 11, 1
2 is attached to the first and second driven pulleys 101 and 102.

The lock direction of the first one-way clutch 105a of the first driven pulley 101 is the back feed direction shown by the arrow b, and the lock direction of the second one-way clutch 105b of the second driven pulley 102 is the feed direction shown by the arrow a. Direction.

In the first and second transport rollers 11 and 12 provided with the first and second one-way clutches 105a and 105b, the second one-way clutch 105b is locked when feeding. Transport roller 1
2 is driven via the second driven pulley 102, while the first one-way clutch 105 a is not locked and the first driven pulley 101 does not transmit the driving force.
The transport roller 11 is rotated by its own weight.

[0048] Thus, towards the linear velocity V ₁₂ of the second conveying roller 12 becomes larger than the linear velocity V ₁₁ of the first conveying roller 11, second conveying roller 12 is a roll label paper 13 with a suitable force While pulling, it can be transported without causing slack.

On the other hand, at the time of back feed, the first transport roller 1 in which the first one-way clutch 105a is locked.
1 is driven via the first driven pulley 101, while the second one-way clutch 105b is not locked, and the second driven pulley 102 does not transmit the driving force.
The transport roller 12 is rotated by its own weight.

As a result, the linear velocity V of the first transport roller 11
Towards ₁₁ becomes larger than the linear velocity V ₁₂ of the second conveying rollers 12, first conveying roller 11 comes to backfeed while pulling the roll label paper 13. This solves the problem of looseness of paper that occurs at the time of back feeding in the conventional system and the problem of label peeling due to the looseness.

Next, a third embodiment of the present invention will be described.

FIG. 4 is a diagram showing a drive system of the roll label paper transport device according to the present embodiment. In the figure, 1
Reference numerals 11 and 112 denote first and second pulleys.
The second pulleys 111 and 112 are fixed to shafts 11a and 12a of the first and second transport rollers 11 and 12 via electromagnetic clutches 115a and 115b, respectively. Further, the first pulley 111 is driven in a back feed direction, and the second pulley 112 is driven in a feed direction by independent driving systems (not shown).

In the present embodiment, at the time of feeding, the electromagnetic clutch 115b of the second pulley 112
Is locked to drive the second transport roller 12 in the feed direction indicated by the arrow a, while the electromagnetic clutch 115a of the first pulley 111 is not locked.

As a result, V ₁₂ > V ₁₁ = 0, and at the time of feeding, only the second transport roller 12 is driven by the second pulley 112, while the first transport roller 11 is twisted by its own weight of paper. . Accordingly, the second transport roller 12 transports the roll label paper 13 without causing slack while pulling the roll label paper 13 with an appropriate force.

On the other hand, at the time of back feed, the electromagnetic clutch 115a of the first pulley 111 is locked and drives the first transport roller 11 in the back feed direction shown by the arrow b, while the electromagnetic clutch 115a of the second pulley 112
Reference numeral 15b prevents the locked state.

As a result, V ₁₁ > V ₁₂ = 0, and at the time of back feed, only the first transport roller 11
The second transport roller 12 is rotated by its own weight while being driven by the roller 11. As a result, the first transport roller 11 feeds back the roll label paper 13 while pulling the roll label paper 13 with an appropriate force, thereby solving the problem of the paper loosening and the label peeling caused by the back feeding in the conventional system.

[0057]

As described above, according to the present invention,
By forming a speed difference between the two transport rollers when transporting and rewinding the roll paper, the paper transport can be performed while always applying tension to the roll paper between the two transport rollers. This makes it possible to prevent the label from peeling off by eliminating the looseness of the paper.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a label printer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a drive system of a roll label paper transport device of the label printer.

FIG. 3 is a diagram illustrating a drive system of a roll label paper transport device of a label printer according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a drive system of a roll label paper transport device of a label printer according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a drive system of a roll label paper transport device of a conventional label printer.

FIG. 6 is a partial side view of FIG. 5;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 roll label paper transport device 11, 12 transport roller 13 roll label paper 3 printing device 105, 105a, 105b, 115a, 115b one-way clutch A label printer

Claims (3)

[Claims] 1. A roll paper is placed on two transport rollers arranged side by side, and the roll paper is transported to a printing unit by a forward / reverse rotation of the two transport rollers and is rewound from the printing unit. In the label printer provided with a roll paper transport device that performs the following, when transporting the roll paper, the transport roller on the downstream side in the transport direction of the two transport rollers of the roll paper transport device is faster than the transport roller on the upstream side in the transport direction. While rotating
A label printer, wherein the upstream transport roller is rotated faster than the downstream transport roller when the roll paper is rewound, so as to form a speed difference between the two transport rollers. 2. A one-way clutch is provided on one of the two conveying rollers, and the one-side conveying roller removes the roll paper on which the one-way clutch is placed when the one-way clutch is unlocked. 2. The label printer according to claim 1, wherein a speed difference is formed between the two transport rollers so that the two transport rollers rotate together with the other transport roller. 3. The two transport rollers are independently driven, and a one-way clutch having a different lock direction is provided for each of the two transport rollers. When the roll paper is transported, one direction clutch of the downstream transport roller is provided. When only the clutch is in the locked state, and when the roll paper is rewound, only the one-way clutch of the upstream transport roller is in the locked state, so that one transport roller is transported to the other via the roll paper placed above. 2. The label printer according to claim 1, wherein a speed difference is formed between the two transport rollers so that the two transport rollers rotate together.