JP2001080803A - Device for buffering drawing load on rolled sheet in printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a load shock absorber for a rolled sheet, capable of smooth ly feeding the rolled sheet and reducing the installation occupancy area to a minimum. SOLUTION: This load shock absorber comprises an arm 22a rotationally movable around a rotational axis 24 of a rolled sheet at a preset angle, a roller 23 extended from the arm 22a to the cross direction of the rolled sheet forwinding a drawn portion of the rolled sheet at the outside of a rolled portion of the rolled sheet and an energizing means for energizing the arm opposite the direction of rotational movement of the arm 22a via the roller 23 with force given when the rolled sheet is fed by a carrying roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer for drawing out roll paper from an end portion thereof by a transport roller and supplying the roll paper to a printing section, and performing printing on the paper. The present invention relates to a drawer load buffering device for buffering a load applied to roll paper at the time.

[0002]

2. Description of the Related Art There is known a printer in which a roll of long recording medium is rolled, and the roll is drawn out by a transport roller to print on the paper. In this type of printer, it is preferable to be able to install a large-diameter roll paper in order to reduce the frequency of replacing the roll paper, but on the other hand, if the diameter of the roll paper is large, the roll paper will be located there when pulled out. Due to the inertia force described above, a large tension acts on the pulled-out portion, and as a result, there is a problem that a slip occurs between the transport roller and the sheet or the sheet is broken. For this reason, there have conventionally been proposed some devices provided with a load buffer device for reducing the load on the roll paper.

FIG. 11 shows an example of a conventional load buffer. As shown in FIG.
It is provided between the installation section of the roll paper R and the printing section 5. The load buffer device 1 includes an arm 2 rotatably supported by a housing.
Is provided with a roller 3 around which the portion r of the roll paper pulled out is wound. Further, a spring 4 is provided which resists rotation of the arm 2 when the roll paper is fed by the transport roller 6. In the figure, when the conveying roller 6 pulls out the roll paper, the pulling force causes the arm 2 to rotate clockwise in the drawing, thereby preventing the pulling force from being directly applied to the roll portion of the roll paper R. I do.

[0004]

However, the conventional load damping device has several problems as described below. (1) When the transport roller 6 starts pulling the roll paper, the arm 2 is rotated because the pulling direction of the roll paper by the transport roller 6 and the rotation direction of the arm 2 are substantially opposite. Requires a large tension.
Depending on the rotation angle of the arm 2, the transport roller 6-roller 3
Between and the roll portion of the roll paper (point A in the figure) -roller 3
The ratio of the relative distance between them changes, so that excessive tension acts on one side while slack occurs on the other side. As a result, smooth feeding of the roll paper R is hindered. (2) The load buffering device 1 needs a sufficient installation area in the housing of the printer in order to secure the moving range of the arm 2, which hinders downsizing of the printer. (3) In mass production of printers, in order to guarantee the stable operation of the load buffer, the positional accuracy of the load buffer with respect to the arrangement of the roll paper and the printing unit is important. Since it is installed independently of the paper installation, it is difficult to guarantee this, and the installation work is troublesome. (4) There is a demand to change the mounting position of the roll paper with respect to the housing or to change the direction of the paper surface supplied to the customer depending on the installation mode of the printer. In such a case, the load buffer of the conventional configuration is required. In the device, the position cannot be flexibly changed according to the change. (5) Also, in order to detect that the remaining amount of roll paper has become small, a near-end sensor may be installed near the roll paper in this type of printer. Installation position must be changed and adjusted.

Accordingly, it is an object of the present invention to provide a shock absorber which does not hinder smooth feeding of roll paper.

Another object of the present invention is to minimize the area occupied by the shock absorber, and to further reduce the size of the printer.

Another object of the present invention is to make it possible to easily improve the accuracy of the installation position of the shock absorber relative to the installation position of the roll paper, and to assure the stable operation of the shock absorber in a mass-produced printer. It is in.

Still another object of the present invention is to change the installation position of the roll paper with respect to the housing or to change the installation position of the paper sheet supplied to the customer side, even when the paper surface direction is changed. It is to provide a load buffer unit.

Another object of the present invention is to provide a near-end sensor element in the load buffer unit.
It is another object of the present invention to eliminate the need to adjust the near-end sensor when changing the installation position of the load buffer unit.

[0010]

In order to achieve the above object, a roll paper pulling load buffering device according to the present invention draws the roll paper from an end thereof by feeding a transport roller and supplies the roll paper to a printing unit. In a printer that performs printing on the upper side, an arm that is rotatable by a predetermined angle around the rotation axis of the roll paper, and outside the roll portion of the roll paper,
A roller that extends from the arm in the width direction of the roll paper and around which a portion from which the roll paper is pulled out is wound, and the arm is rotated via the roller by a force when the roll paper is fed by the transport roller. Biasing means for biasing the arm in a direction opposite to the direction in which the arm is driven.

In the present invention, the movement area of the arm is
Most of them fit inside the roll paper installation area. for that reason,
The installation occupation area of the entire load buffering device with respect to the printer is extremely small. Further, the locus of movement of the roller is a circular arc centered on the rotation axis of the roll paper. For this reason, the tension on both sides of the roller that supports the roll paper withdrawal portion does not greatly change depending on the rotation angle of the arm, and the roll paper can be smoothly pulled out.

Further, in the present invention, it is preferable that the apparatus further comprises an arc-shaped guide centered on the rotation axis of the roll paper, and the urging means is a tension coil spring which expands and contracts along the guide.

In this case, the present invention may be provided with a second tension coil spring for urging the arm in a direction opposite to the urging direction of the tension coil spring.

Further, the biasing means may be a torsion coil spring wound around a rotation shaft of the roll paper.

Further, it is preferable that the rotating shaft of the roll paper, the arm, the roller and the urging means are unitized so as to be detachable from a housing of the printer.

According to the present invention, there is provided a roll paper detachable from a housing of a printer which draws out a roll paper from an end thereof by a transport roller and supplies the roll paper to a printing section, and performs printing on the paper surface. And a drawer load buffer unit. The pull-out load buffer unit according to the present invention includes an arm rotatable around a rotation axis of the roll paper, and an arm substantially parallel to the rotation axis from the arm outside a roll portion of the roll paper. A roller around which a portion from which the roll paper is pulled out is wound, and the arm being rotated in a direction opposite to a direction in which the arm is rotated via the roller by a force when the roll paper is fed by the transport roller. And an urging means for urging the power.

Further, in the present invention, an arcuate guide centered on the rotation axis of the roll paper is further provided, and the urging means has one end fixed to the drawer load buffer unit side and the other end connected to the printer. It is preferable that the tension coil spring be fixed to the housing side of the extension coil and extend and contract along the guide.

In this case, the arm may extend in a radial direction of a substantially disk-shaped plate, and the guide may be provided on the plate.

A second tension coil spring for urging the arm in a direction opposite to the urging direction of the tension coil spring, one end of which is fixed to the pull-out load buffer unit side and the other end is A printer may be provided that is fixed to the housing of the printer.

In this case, it is preferable that the fixing point of the other end of at least one of the tension coil spring and the second tension coil spring to the casing side of the printer is variable.

Further, it is preferable that the guide has a protrusion which comes into contact with the fixed point in accordance with the rotation of the arm.

Further, the drawer load buffering unit is
Further, a near-end sensor element capable of detecting when the winding amount of the roll portion of the roll paper becomes equal to or less than a predetermined amount can be provided.

In this case, it is preferable that the near-end sensor element is mounted so that the position in the radial direction of the roll paper can be changed, and the near-end sensor element can be selectively mounted at any one of a plurality of fixed positions. , May be attached at an appropriate position within a predetermined moving range.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing the internal structure of a printer equipped with a roll paper pull-out load buffer device according to one embodiment of the present invention. In this drawing, only the internal structure is shown, and a casing constituting the outer shape of the printer is omitted.

The printer 10 is a printer for printing receipts used with a POS terminal or the like, and stores roll paper R therein. The print head 1 is provided on a paper path that communicates with the roll paper exit 11 from the storage section for the roll paper R.
2. A paper cutting mechanism 13, a plurality of transport rollers 14, and a guide roller 18 are provided. The transport roller 14 is appropriately driven in accordance with a print command from the host, and the roll paper R is sequentially pulled out from the roll portion. The print head 12 is driven at the same time as the conveyance roller 14 is fed, and desired characters, symbols, and the like are printed on the roll paper R. The printed area on the roll paper R is further conveyed toward the exit 11,
When the trailing end reaches the position of the paper cutting mechanism 13,
As a result, the sheet is cut and separated, and supplied to the user from the carry-out port 11 as a single-sheet receipt.

The printer 10 also includes a collection mechanism 15 for the cut and separated receipt. When the receipt is left in the carry-out port 11 for a predetermined time, the transport roller 14 (excluding the platen roller, that is, the transport roller opposed to the print head 12) reverses the receipt based on a command from the host. And then into the printer 10. The received receipt is carried into the collection path 16 and is sequentially collected in the collection tray 17.

The printer 10 further includes a roll paper load buffering device 20, which functions to reduce the load applied to the roll paper R when it is pulled out. Hereinafter, details of the load buffering device mounted on the printer 10 will be described.

(First Embodiment) In the description, FIGS. 2 to 4 are referred to together with FIG. 2 is an exploded perspective view of the load buffer device according to the present embodiment, FIG. 3 is a perspective view of the same in an assembled state, and FIG. 4 is a cross-sectional view showing the internal structure thereof.

As shown in these figures, the load buffering device 20 has a disk-shaped fixed substrate 21, a rotating plate 22 provided with an arm 22a, and a roller 23. The fixed substrate 21 is for fixing the load buffer device 20 to the surface of the frame 10a of the printer. The rotation axis 24 of the roll paper R is
By fixing the fixed substrate 21 to the frame 10a of the printer integrally with the fixed substrate 21, the rotating shaft 24 is also fixed to the frame. Roll paper R
Is rotatably supported by the rotating shaft 24. A fixed pin 21 for fixing one end of a tension coil spring 25 to be described later is provided on the fixed substrate 21 at an outer peripheral position thereof.
a is formed.

The rotating plate 22 has a disk shape corresponding to the fixed substrate 21 and has, on one side thereof, an arm 22a for supporting a roller 23 integrally. A circular hole 22b is formed at the center of the rotating plate 22 so as to penetrate the rotating shaft 24 of the roll paper R. By inserting the circular hole 22b through the rotating shaft 24, the rotating plate 22 is attached to the fixed substrate 21. It is held rotatably. After the rotation plate 22 is attached, the fixed ring 26 is attached to the rotation shaft 24 to prevent the rotation plate 22 from coming off the fixed substrate 21.

The rotating plate 22 has a guide piece 22c and a fixing pin 22d along the circular outer shape around the fixed substrate 21 side. Two tension coil springs 25a and 25b are arranged outside the guide piece 22c. One end of each of the tension coil springs 25a and 25b is locked by a fixing pin 22d formed on the rotating plate 22, and the other end is fixed by a fixing pin 21a formed on the fixed substrate 21.
Is locked. Each tension coil spring 25a, 25b
The rotating plate 22 is rotated at an arbitrary angle with respect to the fixed substrate 21 so as to generate a restoring force opposing the pulling, so that the fixed pin 21a of the fixed substrate 21 and the fixed pin of the rotating plate 22 are fixed. When the distance between the rotation plate 22d and the rotation plate 22d increases, the rotation plate 22 acts in a direction in which the rotation of the rotation plate 22 is returned. Here, since the tension coil springs 25a and 25b are expanded and contracted along the guide pieces 22c, the amount of expansion and contraction of the spring can be increased, and the acting direction of the force is in the direction of rotation of the rotating plate 22. The distribution of the force is small, and the force of the tension coil spring is efficiently transmitted to the rotating plate 22. According to this configuration, the coil springs 25a,
The amount of expansion / contraction of 5b and the restoring force of the spring are proportional to the rotation angle of the rotating plate 22.

The arm 22a provided on the rotating plate 22
A roller 23 is rotatably fixed to the tip of the roller.
As shown in the figure, a portion of the roll paper R pulled out from the roll portion (hereinafter referred to as a drawer r) is provided on the roller 23.
Is wrapped around. In order to minimize the frictional resistance to the roll paper, the roller 23 is provided with a thin circular blade 23a in its axial direction, and is designed to minimize the contact area of the roll paper R with the paper surface. The roller 23 is in an initial state (initial position of the rotating plate 22), that is, in a state in which the tension coil spring 25 is not acting, with respect to a line L connecting the rotation shaft 24 of the roll paper and the guide roller 18 upstream of the printing unit. It is located above. Roll paper drawer r
Is wound around the roller 23 to form a bypassed roll paper transport path while maintaining a predetermined tension required for the roll paper.

Here, each component of the load buffering device 20 is unitized before mounting on the printer 10,
The unit is fixed to the frame 10a of the printer. Therefore, the relative positional relationship between the rotation axis 24 of the roll paper and the roller 23 is accurately maintained, and problems caused by an error in the mounting position when mounting the roll paper on the printer can be avoided.

Next, the operation of the load buffer 20 will be described. When the conveyance of the roll paper withdrawal portion r is started by the conveyance roller 14 based on a print command from the host, a pulling force is applied to the roll portion of the roll paper to pull it out. Here, the roll portion of the roll paper cannot immediately follow the roll portion due to its inertia force, but the pulling force pulls the roller 23 of the load buffer device substantially downward, thereby pulling the rotating plate 22. The roll paper is rotated by a predetermined angle against the coil spring 25a and fed. At this time, the roller 23
Since the roll paper is rotated by a predetermined angle around the rotation axis of the roll paper, the tension applied to the roll paper on both sides of the roller 23 is distributed in a well-balanced manner, which means that one tension is increased and the other tension is decreased. Absent. For this reason, it is possible to stably feed the roll paper.

When the rotating plate 22 of the load buffer is rotated by pulling the roll paper by the transport roller 14, the tension coil spring 25a is extended to rotate the rotating plate 22 in the opposite direction. Function. That is, the transport roller 1
When the pulling of the roll paper is stopped, or when the feed speed of the transport roller 14 becomes constant after acceleration, the rotating plate 22 rotates in the original direction by the restoring force of the tension coil spring 25a. Thereby, the drawn portion r of the roll paper wound around the roller 23 is pulled along the circumferential direction of the roll paper. Then, this force causes the roll portion of the roll paper to be gradually rotated in the feeding direction, and the roll paper is fed smoothly. At this time, since the rotating plate 22 supporting the roller 23 is pivotally supported around the rotation axis 24 of the roll paper, the roller 23 pulls the roll paper withdrawal portion r along the circumferential direction of the roll paper. . Therefore, the rotational force can be efficiently applied to the roll paper, and smooth feeding of the roll paper is guaranteed.

In the above-described embodiment, the example in which the position of the roller 23 of the load buffering device is positioned above the line segment L and the roll paper draw-out portion r is detoured upward is described. A configuration in which the paper mounting direction is reversed (that is, the roll paper draw-out side is directed upward), the roller 23 is positioned below the line segment L, and the roll paper draw-out portion r is detoured downward. You may take it. In this case, the other tension coil spring 25 of the load damper is used.
b functions for the rotation of the rotation plate 22. That is, the load buffering device 20 can support two types of mounting directions of the roll paper R (see FIGS. 8 and 9). That is,
It is possible to cope with the structure of the printer such as the positional relationship of the print head with respect to the roll paper and the paper path. Further, it is possible to cope with whether the printing surface of the roll paper is located inside or outside. For example, on thermal paper or preprinted paper, the printing surface is predetermined, so
It is effective in such a case.

(Second Embodiment) FIG. 5 is an exploded perspective view showing a load buffer according to another embodiment of the present invention.
In the present embodiment, the same parts as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted. The present embodiment is different from the previous embodiment in that the urging means of the rotating plate 22 is a torsion coil spring 30 mounted on a rotating shaft 24 of roll paper. As shown in the figure, one end of the torsion coil spring 30 is engaged with a hole 31 formed in the rotating plate 22, and the other end is engaged with a groove 32 at the tip of the rotating shaft 24 of the roll paper. Outside the torsion coil spring 30, a cylindrical cover 33 is attached to the rotating shaft 24 by screws 34, so that the roll paper R and the torsion coil spring 30 do not interfere with each other. When the roll paper R is pulled from the initial state by the transport roller 14 and the rotating plate 22 is rotated, the torsion coil spring 30 is twisted to act to return the rotating plate 22 to the initial position. By this operation, the roll paper R is smoothly pulled out as in the case of the first embodiment.

(Third Embodiment) FIGS. 6 to 10 show a printer provided with a roll paper pull-out load buffering device according to still another embodiment of the present invention. FIG. Perspective view showing the internal structure of a mounted printer,
FIG. 7 is an exploded view, and FIG. 8 is a side view thereof. Note that the printer according to the present embodiment has basically the same configuration as the printer 10 shown in FIG. 1, and a basic description thereof is omitted here.

As shown in these figures, the printer 60 according to the present embodiment enables the roll paper R to be stored in the storage space formed by the housing 61. A rotating shaft 62 for rotatably holding the roll paper R is fixed to a wall surface of the housing 61. A plurality of holes 61a to 61c for inserting and fixing the base end of the rotating shaft 62 are formed on the wall surface of the housing 61, and the rotating shaft is inserted into any of the holes 61a to 61c depending on the usage mode. 62 can be fixed.

The printer 60 includes a load buffer unit 70 mounted on the rotation shaft 62. In the present embodiment, the load buffer unit 70 includes a rotating plate 71 having an arm 71a, a roller 72, a tension coil spring 73, and a photo interrupter 74 as a near-end sensor element for roll paper.

The rotating plate 71 has a disk shape substantially similar to that of the rotating plate 22 in the previous embodiment, and is integrally provided with an arm 71a for supporting a roller 72. A circular hole 71 through which the rotating shaft 62 of the roll paper R passes
The rotating plate 71 is rotatably held with respect to the housing 61 by inserting the circular hole 71b into the rotating shaft 62. After attaching the rotating plate 71, the fixing ring 75
Is attached to the rotation shaft 62, thereby preventing the rotation plate 71 from coming off the rotation shaft 62. After the rotation plate 71 is mounted, the roll paper holder 76 is mounted on the rotating shaft 62, and the roll paper R is fitted therein.

The housing 61 of the printer includes a rotating shaft 6.
2 is supported by the hole, and a support plate 63 is provided as a guide for the roll paper R loaded therein. A slide plate 64 that is slightly slidable is attached to the support plate 63, and a hole 64 a that is slightly displaced from the hole of the support plate 63 is formed here. When the tips are inserted into these holes, the periphery of the hole 64 a is engaged with the groove at the tip of the rotating shaft 62. The support plate 63 is rotatably attached to the housing 61, and is opened when the roll paper R is loaded on the rotating shaft 62 and closed when used.

As shown in FIG. 8, the rotary plate 71 has a guide groove 71c around the casing 61 side along the circular outer shape. And, in this guide groove 71c, 2
Two tension coil springs 73a, 73b are arranged. One end of each of the tension coil springs 73a and 73b is locked by a fixing pin 71d formed on the rotating plate 71, and the other end is locked by a fixing pin 77 fixed to the housing 61 side. As in the previous embodiment, each tension coil spring 73
a and 73b function to generate a restoring force opposing the pulling. Therefore, the turning plate 71 is turned with respect to the housing 61, and the fixing pin 77 on the housing side and the turning plate 71 are turned.
The distance between the fixing pin 71d and
It acts in a direction to return the rotation of the rotation plate 71.

The rotating plate 71 and the roller 72 are
At a point where the tension of the two tension coil springs 73a and 73b is balanced, the stationary state (that is, the angle) with respect to the housing 61 is determined. On the wall surface of the housing 61, a plurality of mounting holes 61d for fixing pins 77 for fixing one ends of the tension coil springs are formed on an arc around the rotation shaft 62, so that the mounting positions of the fixing pins 77 are changed. It can be moved.

FIG. 9 shows a mounting hole 61 different from the example of FIG.
An example is shown in which the tension coil springs 73a and 73b are attached using d. Thus, the fixing pin 77
By changing the mounting position, the balance point of the tension of the two tension coil springs 73a and 73b is changed, and therefore, the mounting angle of the rotating plate 71 and the roller 72 can be adjusted. When the rotating shaft 62 is fixed to the hole 61b or 61c, the mounting hole 61e or 61f is used for this purpose.

The arm 71a provided on the rotating plate 71
A roller 72 is rotatably fixed to the end of the roller.
Since the configuration of the roller 72 is the same as that in the previous embodiment, the description is omitted here. When the roll paper drawer r is wound around the roller 72, a bypass path of the roll paper is formed while maintaining a predetermined tension required for the roll paper.

The load buffer unit 70 according to the present embodiment
Further includes a photo interrupter 74. The photo interrupter 74 functions as a near-end sensor element of the roll paper R mounted on the rotating shaft, that is, an element for detecting and notifying that the end of the roll paper is approaching.
The photo interrupter 74 is attached to the rotating plate 71 via a mounting bracket 78 so as to be adjustable in position. As shown in FIGS. 7 and 8, the mounting bracket 78 is a long plate-shaped member, and has a fixing area for the photointerrupter 74 between the mounting portions 78a and 78b at both ends.

On the other hand, on the surface of the rotating plate 71, a shaft portion 80 for rotatably locking one mounting portion 78a of the mounting bracket,
An adjustment attachment portion 81 is formed so that the attachment position of the other attachment portion 78b can be changed. The adjustment mounting portion 81 is formed with an arc-shaped screw groove 81a centered on the shaft portion 80 and a plurality of screw holes 81b arranged along the same. The mounting portion 78b of the mounting bracket 78 is 82, the screw groove 81
It is fixed to an arbitrary position of a or any of the screw holes 81b. The functional surface of the photo interrupter 74 attached to the rotating plate 71 via the attachment fitting 78 is such that the side surface of the roll paper R can face the slit 83 extending in the radial direction of the roll paper R. By fixing one end of the mounting bracket 78 to the screw groove 81a, the photo interrupter 74 can be fixed at a position free from the rotation shaft 62. By fixing one end of the mounting bracket 78 to any of the screw holes 81b, the photo interrupter 74 can be fixed at a stepwise position from the rotation shaft 62.

As shown in FIG. 8, the load buffer unit 70 according to the present embodiment further comprises a photo interrupter 84 as a paper end sensor element,
1a Prepare at the tip. The photo-interrupter 84 is disposed with its functional surface facing the roll paper wound around the roller 72. When the roll paper R is completely used and its end passes through it, the photo interrupter 84 detects this and the roll paper R is detected. The end signal is output. The photo interrupter 84 is
The installation mode of the load buffer unit 70, that is, the roller 72
The attachment position can be adjusted in accordance with the direction and angle of winding of the roll paper with respect to.

(Fourth Embodiment) FIG. 10 is a side view showing another mode of installing the load buffer unit 70 in a printer housing. This example shows a usage example in which the loading direction of the roll paper R with respect to the rotation shaft 62 is reversed. That is, the end r of the roll paper is pulled out from the lower side, wrapped over the roller 72, and sent to the printing unit. The following procedure is taken to change from the installation state shown in FIG. 8 to the installation state shown in this figure. First, the load buffer unit 70 is removed from the rotating shaft 62. This operation is performed by removing the fixing pin 77 of the tension coil spring and removing the roll paper holder 76 and the fixing ring 75. Next, the rotating shaft 62 is removed from the hole 61a of the housing 61, and attached to the position of the hole 61c. Then, the load buffer unit 70 is mounted on the rotating shaft 62 and fixed by the fixing ring 75 and the roll paper holder 76. Rotating plate 7
One of the mounting holes 61f of the fixing pin 77 is selected in accordance with the appropriate mounting angle, and one end of the tension coil spring 73 is fixed here. Finally, the mounting direction of the photo interrupter 84 as the paper end sensor element is adjusted, and the change of the installation position is completed.

What is important in the above procedure is that it is not necessary to change and adjust the mounting position of the photointerrupter 74 as the near-end sensor element according to the mounting position of the load buffer unit 70. . In the printer according to the present embodiment, the change of the mounting position of the photo interrupter 74 with respect to the rotation axis of the roll paper is completed by the change of the installation position of the load buffer unit 70.

The rotating plate 71 is provided with a projection 71e for guiding the tension coil springs 73a and 73b, and prevents the springs from coming off together with the guide grooves 71c. In addition, the protrusion 71e is configured to come into contact with the fixing pin 77 when the rotation plate 71 rotates, and also has a function as a stopper so that the rotation plate 71 does not rotate more than a predetermined amount.

As described above, one embodiment of the present invention has been described with reference to the drawings. However, the present invention is not limited to the matters shown in the above embodiment, and is described in the claims and the detailed description of the invention. The range in which those skilled in the art can make changes and applications based on well-known techniques is included. In the above embodiment, the rotating plates 22 and 71 are disk-shaped, but the rollers 23 and 72 are connected to the rotating shafts 24 and 62 of the roll paper.
Any other shape may be used as long as it can be rotated about.

[0054]

As described above, according to the present invention, the following effects can be obtained. (1) In the present invention, most of the movement area of the arm falls within the roll paper installation area. Therefore, the installation occupation area of the entire load buffering device with respect to the printer is extremely small, and does not hinder downsizing of the printer. (2) The movement trajectory of the roller is a circular arc centered on the rotation axis of the roll paper. For this reason, the tension on both sides of the roller that supports the roll paper withdrawal portion does not greatly change depending on the rotation angle of the arm, and the roll paper can be smoothly pulled out. (3) By setting the rotation axis, arm, roller, and biasing means of the roll paper as a detachable unit with respect to the housing of the printer, it is possible to easily improve the installation position accuracy of the shock absorber with respect to the roll paper installation position. As a result, stable operation of the shock absorber in a mass-produced printer is guaranteed. (4) In the present invention, since the load buffering device is configured as a unit, it is desirable to change the mounting position of the roll paper with respect to the housing or change the orientation of the paper supplied to the customer side, depending on the installation mode of the printer. Can be flexibly responded to the request. (5) It is not necessary to change and adjust the installation position of the near-end sensor in accordance with the change of the installation position of the roll paper, thereby making it possible to easily change the installation position of the roll paper.

[Brief description of the drawings]

FIG. 1 is a side view showing the internal structure of a printer equipped with a roll paper load buffer device according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the load buffer according to the embodiment.

FIG. 3 is a perspective view of the load buffer device according to the embodiment in an assembled state.

FIG. 4 is a sectional view showing the internal structure of the load buffer device according to the present embodiment.

FIG. 5 is an exploded perspective view showing a load buffer according to another embodiment of the present invention.

FIG. 6 is a perspective view showing an internal structure of a printer equipped with a drawer load buffer according to still another embodiment of the present invention.

FIG. 7 is an exploded view of FIG.

FIG. 8 is a side view of FIG. 6;

FIG. 9 is a side view showing an installation mode in which a tension coil spring is mounted using a mounting hole different from the example of FIG. 8;

FIG. 10 is a side view showing another installation mode of the load buffer unit of FIG. 6 with respect to a printer housing.

FIG. 11 is a diagram showing an example of a conventional load buffer device.

[Explanation of symbols]

 R roll paper 10 printer 10a frame 11 carry-out port 12 print head 13 paper cutting mechanism 14 transport roller 15 collection mechanism 16 collection path 17 collection tray 18 guide roller 20 load buffer 21 fixed substrates 21a, 21b fixed pin 22 rotating plate 22a arm 22b Circular hole 22c Guide piece 22d Fixing pin 23 Roller 23a Circular blade 24 Rotating shaft 25a, 25b Tension coil spring 26 Fixing ring 30 Torsion coil spring 31 Hole 32 Groove 33 Cover 34 Screw

Claims (20)

[Claims] 1. A printer that draws roll paper from an end thereof by feeding a transport roller and feeds the roll paper to a printing unit, and performs printing on the paper surface, wherein the printer is rotatable by a predetermined angle about a rotation axis of the roll paper. And a roller that extends in the width direction of the roll paper from the arm outside the roll portion of the roll paper and around which a portion from which the roll paper is pulled out is wound. A biasing means for biasing the arm in a direction opposite to a direction in which the arm is rotated via the roller by a force when the roll is fed, and a load for pulling out roll paper in the printer. Shock absorber. 2. The apparatus according to claim 1, further comprising an arc-shaped guide centered on a rotation axis of the roll paper, wherein the urging means is a tension coil spring that expands and contracts along the guide. A buffer device for pulling out roll paper in the printer described in the above. 3. A load for pulling out roll paper in a printer according to claim 2, further comprising a second tension coil spring for urging the arm in a direction opposite to a direction in which the tension coil spring is biased. Shock absorber. 4. The apparatus according to claim 1, wherein said urging means is a torsion coil spring wound around a rotating shaft of said roll paper. 5. The printer according to claim 1, wherein the rotation axis of the roll paper, the arm, the roller, and the urging unit are unitized so as to be detachable from a housing of a printer. A load buffer device for pulling out roll paper in the printer according to claim 3 or 4. 6. A buffer for pulling out roll paper detachable from a housing of a printer that draws out roll paper from an end thereof and feeds it to a printing unit by feeding of a conveying roller, and detaches the roll paper from the housing of the printer. An arm rotatable about a rotation axis of the roll paper, and an arm extending substantially parallel to the rotation axis from the arm outside a roll portion of the roll paper, A roller around which a portion to be pulled out is wound, and a bias for urging the arm in a direction opposite to a direction in which the arm is rotated via the roller by a force when the roll paper is fed by the transport roller. And a load means for loading the roll paper in the printer, comprising: 7. The printer further comprises an arc-shaped guide centered on the rotation axis of the roll paper, wherein the urging means has one end fixed to the pull-out load buffer unit and the other end connected to the housing of the printer. 7. The load buffer unit for pulling out roll paper in a printer according to claim 6, further comprising a tension coil spring that is fixed to the extension and retractable along the guide. 8. The load buffer unit according to claim 7, wherein the arm extends in a radial direction of a substantially disk-shaped plate, and the guide is provided on the plate. 9. The load buffer unit according to claim 7, wherein a fixed point of the one end of the tension coil spring with respect to a housing side of the printer is variable. 10. A second tension coil spring for urging the arm in a direction opposite to the urging direction of the tension coil spring, one end of which is fixed to the pull-out load buffer unit side, and the other end is 10. The load buffer unit for pulling out roll paper in a printer according to claim 7, further comprising a unit fixed to a housing side of the printer. 11. The apparatus according to claim 1, wherein one end of the second tension coil spring is fixed to the fixing point.
0. A load buffer unit for pulling out roll paper in the printer according to 0. 12. The load for pulling out roll paper in a printer according to claim 7, wherein the guide has a protrusion that comes into contact with the fixed point in accordance with the rotation of the arm. Buffer unit. 13. The printer according to claim 1, wherein the biasing means is a torsion coil spring wound around a rotation shaft of the roll paper, one end of which is fixed to the drawer load buffering unit side, and the other end is a housing side of the printer. 7. The load buffer unit for pulling out roll paper in the printer according to claim 6, further comprising a unit fixed to the printer. 14. The apparatus according to claim 6, further comprising a near-end sensor element for detecting when the amount of winding of the roll portion of the roll paper falls below a predetermined amount. 3. A load buffer unit for pulling out roll paper in the printer described in 1. above. 15. The load buffer unit according to claim 14, wherein the near-end sensor element is mounted so as to be able to change the position of the roll paper in the radial direction. 16. The buffer unit according to claim 15, wherein the near-end sensor element is selectively attached to any one of a plurality of fixed positions. 17. The buffer unit according to claim 15, wherein the near-end sensor element is mounted at an appropriate position within a predetermined moving range. 18. A printer according to claim 6, further comprising a load buffer unit for pulling out roll paper. 19. A paper end sensor for detecting an end of a sheet pulled out from the roll sheet is provided near a roller of the pull-out load buffer unit.
8. The printer according to 8. 20. The printer according to claim 18, wherein a plurality of installation positions of the drawer load buffer unit are provided on the housing.