JP2001146346A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of adjusting tension imparted to carrying paper and capable of coping with thin paper and thick paper by a single machine kind. SOLUTION: This printer has a frame 12 having a paper housing part 14, a printing mechanism 30, a paper carrying passage ranging to the printing mechanism 30 from the paper housing part 14 and a tension bar 15 for imparting tension to paper S. A tension bar installing hole 40 is formed in a side plate 11 for constituting the frame 12. The installing hole 40 has first to third engaging holes 42a to 42c for engaging with the tension bar 15, and when engaging the tension bar 15 in this order, the tension to be imparted to the paper S is adjusted so as to gradually become weak.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, POS (Poi)
The present invention relates to a small-sized printer such as an electronic cash register used in an nt of sale system, and more particularly, to a printer provided with a mechanism for applying tension to transported paper.

[0002]

2. Description of the Related Art As a printer of the above-mentioned electronic cash register, a sheet stored in a roll is pulled out, printed on the sheet by a thermal head in a transport path, and then cut and discharged as a receipt. Configurations are known. This type of printer is usually provided with a configuration in which the paper transport path is meandering in an S-shape to apply tension to the paper in order to suppress the problem of skew or meandering as the paper is transported. ing. In order to apply tension to the sheet, a means for pressing a tension bar extending in the width direction of the sheet against one side of the sheet is generally adopted.

[0003]

However, if the tension is applied to the relatively thick and stiff paper as described above, the conveyance resistance is increased, so that a load is imposed on the conveyance mechanism and the paper is discharged. This causes a problem such as a strong curl on the cut sheet. Therefore,
It was necessary to set the printer model for each sheet thickness, such as for normal paper (thin paper) and thick paper. In this case, the printer for thick paper has a paper transport path that is linear. However, increasing the number of printer models in this way is not efficient in terms of manufacturing, and has led to an increase in cost.

Accordingly, the present invention can vary the tension applied to a transport sheet, thereby applying (or not applying) an appropriate tension corresponding to the thickness to the sheet, and providing a single model. It is an object of the present invention to provide a printer capable of handling thin paper and thick paper.

[0005]

According to the present invention, there is provided a frame having a paper storage section, a printing mechanism, a paper transport path extending from the paper storage section to the printing mechanism, and a sheet supported by the frame and transported through the paper transport path. And a tension bar that applies tension to the sheet by bending the transport path of the sheet, wherein the tension bar is movable with respect to a frame so that the intensity of the tension applied to the sheet is variable and arbitrary. Are supported such that they can be arranged at the tension application position.

According to the present invention, when thin paper is used, the tension bar is arranged at a position where the paper transport path is largely bent and strong tension is applied. On the other hand, when a thick sheet is used, the tension bar is disposed at a position where the sheet conveyance path is gently bent and a weak tension is applied. The tension bar may be completely retracted from the paper transport path and arranged at a position where no tension is applied to the paper transport path. In this way, by moving the tension bar according to the thickness of the paper and placing it there,
An appropriate tension according to the thickness can be applied to the paper. Therefore, it is possible to provide a printer that can handle thin paper and thick paper with one model.

In the present invention, the tension bar can be disposed at at least two positions: a tension application position for applying tension to the paper, and a tension non-application position where the tension bar is retracted from the paper conveyance path and does not apply tension to the paper. Including the form to be. In this case, there are two choices as to whether or not to apply tension to the sheet.

In a preferred embodiment of the present invention, the tension bar is provided with a damper for absorbing a part of a recoil received from the sheet when the tension is applied to the sheet. The tension bar receives a reaction from the sheet because the tension is applied to the sheet. If the recoil is excessive, problems occur such that the sheet conveyance resistance increases and the sheet breaks. The recoil of the sheet with respect to the tension bar is large especially at the start of sheet conveyance. Therefore, by providing the above damper and absorbing a part of the recoil received from the sheet by the damper, the occurrence of the above-mentioned problem can be suppressed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. (1) First Embodiment FIG. 1 is a left side view schematically showing a printer according to a first embodiment of the present invention. This printer is a small printer used as an electronic cash register,
The printer includes a printer body 10 and a cover 20. FIG.
Shows a state where the cover 20 is closed. The printer body 10 includes a pair of left and right side plates 11 (the left side plate 1 in FIG. 1).
(Only one can be seen). A paper storage unit 14 is defined inside the frame 12 by the left and right side plates 11 and the paper holder 13. The paper storage unit 14 stores the heat-sensitive paper S accumulated in a roll shape. The leading end of the paper S is from the lower side to the front side (the right side in FIG. 1).
It is stored so as to be pulled out. Paper S pulled out
Is an inclined surface 13 of the paper holder 13 having a forward rising gradient.
a is conveyed upward (on the paper conveyance path).

[0010] One end of the cover 20 has a frame 12
1 is hinged to the upper portion of the rear portion (the left side in FIG. 1), and is attached to the frame 12 so as to be openable and closable so as to close the sheet storage portion 14. A hook 21 is formed at a front end portion on the free end side of the cover 20. The hook 21 is detachable from a hook (not shown) formed on the frame 12 so that the closed state of the cover 20 is maintained when engaged. On the lower surface of the front end of the cover 20, a bulged portion 22 having a triangular cross section is formed extending in the lateral direction. The front surface of the bulging portion 22 faces the upper end of the inclined surface 13a of the paper holder 13 substantially in parallel with the paper transport path therebetween, with the cover 20 closed.

A printing mechanism 30 is provided at the upper part of the front part of the printer. The printing mechanism 30 includes a thermal head 31 fixed to the frame 12 and a platen roller 32 rotatably mounted on the cover 20. The platen roller 32 is rotated counterclockwise in the figure by driving means (not shown), and is brought into pressure contact with the surface of the thermal head 31 when the cover 20 is closed. The transported sheet S is sandwiched between the two, and printing is performed on the sheet S by the thermal head 31 in that state. Then, the sheet S is transported upward by the frictional action between the rotating platen roller 32 and the thermal head 31. Although not shown, a cutter mechanism that cuts the printing paper that has passed through the printing mechanism 30 is disposed downstream (upper side) of the printing mechanism 30 in the paper transport path. This cutter mechanism is provided on the fixed blade provided on the cover 20 and on the frame 12 and cooperates with the fixed blade to form the sheet S.
And a movable blade that cuts off

In FIG. 1, reference numeral 15 denotes a tension bar for imparting tension to the transported paper, and mounting holes 40 for supporting the tension bar 15 over the side plate 11 are formed in the left and right side plates 11. ing. As shown in FIG. 1, the mounting hole 40 is located on the inclined surface 13a of the paper holder 13 when viewed from the side.
1 are formed symmetrically. The mounting hole 40 is
A first escape hole 41A having a round hole shape formed at an upper portion, a second escape hole 41B having a long hole shape communicating with the first escape hole 41A, and formed below and behind the first escape hole 41A; A first engagement hole 42a opening to the first escape hole 41A, and a second engagement hole 41a;
B is a modified hole having second and third engagement holes 42b and 42c opening to B. Both ends of the tension bar 15 are engaged with any of the engagement holes 42 a to 42 c in the left and right mounting holes 40, and are horizontally hung on the left and right side plates 11. The first to third engagement holes 42a to 42c are arranged in this order from the top, and the arrangement direction is slightly inclined forward. First
The first to third engagement holes 42a to 42c are formed in such a manner that they extend rearward and then rise slightly inclining forward.
The third elastic pieces 43a to 43c are formed.

The first engagement hole 42a is formed below the first escape hole 41A. The first in the first engagement hole 42a
The width of the opening to the escape hole 41A is determined by the first elastic piece 43a. Its width is slightly smaller than the diameter of the tension bar 15, and this narrow portion 44a causes the first
The tension bar 15 engaged with the engagement hole 42a does not easily come off the first escape hole 41A. Also,
On the side of the first escape hole 41A, a stopper piece 45 extending continuously upward from the first elastic piece 43a is formed.

The second and third engagement holes 42b and 42c are formed in front of the second escape holes 41B, respectively. Second
Also in the third engagement holes 42b and 42c, the first engagement holes 42
As in the case of a, a narrow portion 44 slightly smaller than the diameter of the tension bar 15 is formed in the opening to the second escape hole 41B.
b, 44c are formed respectively. These narrow parts 4
4b, 44c, the second and third engagement holes 42b, 42c
The tension bar 15 engaged with the second escape hole 4
1B.

At both ends of the tension bar 15, rings 16 for retaining are fixed. By arranging these rings 16 outside the left and right side plates 11, the movement of the tension bar 15 in the lateral direction (axial direction) is restricted. The first and second relief holes 41A, 41
B is much larger than ring 16.

Next, the operation of the first embodiment will be described. According to the first embodiment, the strength of the tension applied to the sheet S by the tension bar 15 can be adjusted in three stages according to the thickness of the sheet S. The strength of the tension applied to the sheet S is highest when the tension bar 15 is disposed in the first engagement hole 42a, and decreases in the order of the second and third engagement holes 42b and 42c.

FIG. 1 shows a state in which the tension bar 15 is disposed in the first engagement hole 42a. In order to arrange the tension bar 15 in the first engagement hole 42a, first, one end of the tension bar 15 is connected to one of the left and right first relief holes 4a.
1A and the other end is arranged in the frame 12,
Next, the other end is inserted into the other first clearance hole 41A, and both ends are arranged in the left and right first clearance holes 41A. Next, the inner portions of the ring 16 at both ends of the tension bar 15 are arranged in the narrow portion 44a, and the first elastic pieces 43a are pushed into the first engagement holes 42a and elastically deformed so as to be engaged. Thereby, the tension bar 15 is connected to the left and right first engagement holes 42a.
Spanned horizontally.

In this arrangement, the tension bar 15 is located above and behind the protruding end of the bulging portion 22 of the cover 20. The paper S reaches the printing mechanism 30 via a largely bent S-shaped path which is wound on the upper side of the tension bar 15 and then goes under the bulging portion 22. On paper S,
By pressing the tension bar 15 from below, a relatively strong tension is applied, and skewing and meandering are suppressed. Printing is performed on the sheet S by the printing mechanism 30, and thereafter, the portion discharged to the outside of the apparatus is cut by the cutter mechanism.

Next, from the state in which the tension bar 15 is disposed in the first engagement hole 42a as described above, the second engagement hole 4
A method of moving the tension bar 15 to 2b will be described. FIG.
Shows a state in which the tension bar 15 is arranged in the second engagement hole 42b.

The tension bar 15 is pushed from the first engagement hole 42a in the direction of the first relief hole 41A, and is moved to the first relief hole 41A through the narrow portion 44a while elastically deforming the first elastic piece 43a. Further, the tension bar 15 is detached from the frame 12 in a reverse manner in which both ends of the tension bar 15 are disposed in the first relief holes 41A. Next, after inserting one end of the tension bar 15 into the left or right second relief hole 41B and arranging the other end in the frame 12,
The other end is inserted into the other second clearance hole 41B, and both ends are arranged in the left and right second clearance holes 41B. Next, the inside of the ring 16 at both ends of the tension bar 15 is
4b, while being elastically deformed, the second elastic piece 43b is pushed into and engaged with the second engagement hole 42b. This allows
The tension bar 15 extends horizontally across the left and right second engagement holes 42b.

When the tension bar 15 is disposed in the second engagement hole 42b, as shown in FIG.
Is located slightly below and behind the protruding end of the bulging portion 22 of the cover 20. For this reason, the transport path of the sheet S becomes a gently bent S-shape, and the tension given by the tension bar 15 is set to be weaker than when the sheet S is disposed in the first engagement hole 42a.

Next, in order to dispose the tension bar 15 in the third engagement hole 42c, the tension bar 15 is pushed out from the second engagement hole 42b into the second relief hole 41B, and then is pushed into the third engagement hole 42c. Engage in a similar manner. FIG. 3 shows a state where the tension bar 15 is arranged in the third engagement hole 42c. When the tension bar 15 is disposed in the third engagement hole 42c, the transport path of the sheet S is slightly curved, and the tension to be applied is the second engagement hole 42c.
It is set to be weaker than when it is arranged at b.

According to the first embodiment, the sheet S is formed by engaging the tension bar 15 with any one of the first to third engagement holes 42a to 42c formed in the left and right side plates 11. A suitable tension according to the thickness of the sheet S can be applied to the sheet S. That is, one of the first to third engagement holes 42a to 42c is appropriately selected in the order of the thickness of the sheet S, and the tension bar 15 is disposed. Therefore, the printer can handle thin paper and thick paper with one model.

(2) Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In these drawings, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the second embodiment, L-shaped mounting holes 50 are formed in the left and right side plates 11 instead of the mounting holes 40 of the first embodiment. The mounting hole 50 is slightly inclined forward and extends vertically, and a vertical portion 50 having an upper end serving as a first engagement portion 51a.
A and an L-shaped long hole having a horizontal portion 50B inclined forward and downward from the lower end of the vertical portion, and a groove-shaped second engaging portion 51b extending short upward is formed at the tip of the horizontal portion 50B. Have been.
The tension bar 15 is stretched over the left and right side plates 11 so as to slide freely in the mounting hole 50. A vertical portion 50 above the mounting hole 50 on the inner surface of the side plate 11.
A pin (not shown) is formed on the extension upper portion of A, and a coil spring (damper) 52 is hung between the pin and the tension bar 15.

As shown in FIG. 4, the tension bar 15
Is biased by the coil spring 52 to be engaged with the first engagement portion 51a, and this position is set as a tension applying position. Further, when the tension bar 15 is moved along the mounting hole 50 against the pulling force of the coil spring 52 and is engaged with the second engagement portion 51b, the tension bar 15 is moved to a retreat position where the tension bar 15 retreats from the paper transport path. (The state shown in FIG. 5). At this retracted position, no tension is applied to the sheet S. The tension bar 15 at the retracted position is held at that position by the pulling force of the coil spring 52. In the second embodiment, the front portion of the paper holder 13 is bent so as to escape from the mounting hole 50 for convenience of forming the mounting hole 50.

In the second embodiment, the tension bar 1
5, the tension bar 15 is attached to the first engaging portion 51a, and as shown in FIG.
Is located above and behind the protruding end. And the paper S
Are wound on the upper side of the tension bar 15, and
Reaches the printing mechanism 30 via a largely bent S-shaped path that goes around below. The tension is applied to the sheet S by pressing the tension bar 15 from below, and skew and meandering are suppressed. Further, the tension bar 15 that applies tension to the sheet S always receives a recoil from the sheet S, but the recoil is effectively absorbed by the coil spring 52 expanding and contracting and the tension bar 15 swinging. Is done. Therefore, it is possible to avoid a problem that the transport resistance of the sheet S is increased or the sheet S is broken. The usage mode in which the tension bar 15 is arranged at the tension application position is a case where the paper S to be used is relatively thin and it is preferable to apply an appropriate tension to the paper S.

On the other hand, as shown in FIG. 5, when the tension bar 15 is engaged with the second engaging portion 51b of the mounting hole 50 and is arranged at the retracted position, the paper S is transported straight to the printing mechanism 30. The usage mode in which the tension bar 15 is arranged at the retracted position is a case where the sheet S is relatively thick and it is preferable that no tension is applied.

In the second embodiment, the tension bar 15 is disposed at one of the position where the tension is applied to the sheet S and the position where the tension is not applied to the sheet S.
It is possible to appropriately select and use whether or not to apply tension to the sheet S according to the thickness of the sheet S.

(3) Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIGS. In these drawings, the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the third embodiment, an elongated mounting hole 60 corresponding to the vertical portion 50A of the mounting hole 50 of the second embodiment is formed in the left and right side plates 11, and the tension bar 15 It is supported so as to be slidable along the mounting hole 60. Also in this case, the coil spring 52 for absorbing the recoil of the sheet S is hung on the tension bar 15.

Inside the left and right side plates 11, levers 61 for determining the position of the tension bar 15 are provided symmetrically. The lever 61 is formed in a crank shape by a thin plate, and has one end fixed to a rotating shaft 62 spanned at a predetermined position in front of and below the side plate 11. The rotation shaft 62 is rotatably supported on the side plate 11 around the axis, and the left and right levers 61 are rotatable integrally with each other about the rotation shaft 62. The lever 61 is provided between the side plate 11 and the coil spring 52.
Is rotatable so as to be in sliding contact with the inner surface of the. Also,
The lever 61 has a length whose upper end protrudes upward from the side plate 11.

A first projection 63a, a second projection 63b, a third projection 63c, and a fourth projection 63d slightly projecting inward are provided at a predetermined interval on the upper end edge of the inner surface of the side plate 11. ,
In addition, they are arranged along the upper edge. The valley between the first convex portion 63a and the second convex portion 63b is defined as a first engaging portion 64a. Hereinafter, the second convex portion 63b and the third convex portion 63c will be described.
Is a second engaging portion 64b, and a portion between the third convex portion 63c and the fourth convex portion 63d is a third engaging portion 64c.

The rotated lever 61 can be engaged with each of the engaging portions 64a to 64c. FIG. 6 shows a state in which the lever 61 is engaged with the forefront first engagement portion 64a. At this time, the lever 61 is retracted from the mounting hole 60, and the tension bar 15 is moved by the coil spring 52 to the mounting hole 60a. At the top of the In order to engage the lever 61 with any of the engaging portions 64a to 64c, the lever 61 is rotated so that each of the convex portions 63b, 63
This is possible by overcoming c. Therefore, it is preferable that each of the protrusions 63b and 63c has a shape that allows the lever 61 to easily get over. Since the left and right levers 61 are interlocked, one of the left and right levers 61 may be operated.

As shown in FIG. 6, when the lever 61 is engaged with the first engaging portion 64a and retracted from the mounting hole 60, the tension bar 15 is higher than the protruding end of the bulging portion 22 of the cover 20. And located at the back. Then, the paper S reaches the printing mechanism 30 via a largely bent S-shaped path which is wound around the tension bar 15 and then goes under the bulging portion 22, and the paper S is provided with the tension bar from below. 1
5 is pressed to apply tension.

As shown in FIG. 7, when the lever 61 is engaged with the second engaging portion 64b, the tension bar 15 is pushed downward by the lever 61 and the coil spring 52
Is disposed at a position where it comes into contact with the lever 61 due to the pulling force. The tension bar 15 is located below and behind the protruding end of the bulging portion 22 of the cover 20, and the transport path of the sheet S has an S-shape that is slightly bent. In this case, the tension applied by the tension bar 15 is
Is set to be weaker than when it is engaged with the first engagement portion 64a.

As shown in FIG. 8, when the lever 61 is engaged with the third engagement portion 64c, the tension bar 15 is disposed at a position further pressed downward, and the transport path of the sheet S is slightly curved. In this state, the applied tension is set to be weaker than when the lever 61 is engaged with the second engagement portion.

According to the third embodiment, the position of the tension bar 15 is adjusted by engaging the left and right levers 61 with any one of the first to third engagement portions 64a to 64c. The appropriate tension can be applied to the sheet S according to the degree. That is, one of the first to third engaging portions 64a to 64c is appropriately selected in the order of the thickness of the sheet S, and the lever 61 is engaged.

[0039]

As described above, according to the present invention,
Since the tension applied to the transport paper can be adjusted,
Appropriate tension according to the thickness of the paper can be applied to the transport paper. As a result, it is possible to provide a printer that can handle thin paper and thick paper with one model.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a printer according to a first embodiment of the present invention, showing a state in which the tension applied to a transport sheet by a tension bar is the strongest.

FIG. 2 is a side view schematically showing the printer according to the first embodiment of the present invention, and shows a state in which the tension applied to the conveyed paper by a tension bar is medium.

FIG. 3 is a side view schematically showing the printer according to the first embodiment of the present invention, showing a state in which the tension applied to the transport paper by the tension bar is the weakest.

FIG. 4 is a side view schematically showing a printer according to a second embodiment of the present invention, and shows a state in which tension is applied to a transport sheet by a tension bar.

FIG. 5 is a side view schematically showing a printer according to a second embodiment of the present invention, showing a state in which a tension bar is retracted from a sheet conveying path.

FIG. 6 is a side view schematically showing a printer according to a third embodiment of the present invention, and shows a state in which the tension applied to a transport sheet by a tension bar is the strongest.

FIG. 7 is a side view schematically showing a printer according to a third embodiment of the present invention, and shows a state in which the tension applied to the transport paper by a tension bar is medium.

FIG. 8 is a side view schematically showing a printer according to a third embodiment of the present invention, and shows a state in which the tension applied to a transport sheet by a tension bar is the weakest.

[Explanation of symbols]

12: frame, 14: paper storage unit, 15: tension bar, 30: printing mechanism, 52: coil spring (damper), S: paper.

Claims (3)

[Claims] A frame having a paper storage unit, a printing mechanism, a paper conveyance path extending from the paper storage unit to a printing mechanism, and a paper conveyance path supported by the frame and conveyed through the paper conveyance path bent. A tension bar that applies tension to the paper by causing the tension bar to move freely with respect to the frame so that the intensity of the tension applied to the paper is variable, and to provide an arbitrary tension application position. A printer characterized by being supported so that it can be arranged in a printer. 2. The frame according to claim 1, wherein the tension bar has at least two positions with respect to the frame: a tension application position for applying tension to the paper, and a tension non-application position for retreating from the paper conveyance path and applying no tension to the paper. The printer according to claim 1, wherein the printer can be arranged. 3. The printer according to claim 1, wherein the tension bar is provided with a damper that absorbs a part of a recoil received from the paper when the tension is applied to the paper.