JP3644823B2 - Receipt printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a receipt printer that uses roll paper.
[0002]
[Prior art]
First, a conventional example of this type of receipt printer is shown in FIG. Opposite side plates 1 and a main frame 2 are fixedly provided inside a housing (not shown) of the receipt printer. The opposite side plates 1 are formed with cutouts 3 with open upper edges, and roll paper support shafts 4 as roll paper support portions are detachably supported in these cutouts 3. The roll paper support shaft 4 supports the core 6 of the roll paper 5 in a penetrating state. One of the opposing side plates 1 may be formed as a door that can be opened and closed with respect to the local side plate 1.
[0003]
A head frame 9 urged upward by a spring 8 is rotatably supported on shafts 7 erected on both sides of the main frame 2, and a thermal head 10 as a print head is fixedly supported on the head frame 9. Has been. A platen 11 facing the thermal head 10 is rotatably supported on both sides of the main frame 2. The platen 11 is driven by a motor (not shown) and has a function as a roll paper transport unit that draws the roll paper 5 toward the thermal head 10. Further, on both sides of the main frame 2, supported are cutters 12 which are arranged near the downstream side of the platen 11 and cut the printed roll paper 5 in units of receipts.
[0004]
Further, the main frame 2 is provided with a guide 13 for guiding the roll paper 5 between the thermal head 10 and the platen 11. The guide 13 includes a guide plate 14 through which the roll paper 5 passes opposite to each other, and a rotatable guide roller 15 disposed on the upper portion of the guide plate 14.
[0005]
Further, the guide 13 is provided with a damper device 16. The damper device 16 includes a damper plate 18 that is rotatably supported around a fulcrum shaft 17, a damper roller 19 that is rotatably supported on both sides of the free end side of the damper plate 18, and a damper plate 18. A return spring 20 that is biased counterclockwise and a stopper 20a that restricts the set position of the damper plate 18 by the biasing force of the return spring 20 are provided.
[0006]
Next, the operation will be described. The roll paper 5 is supported by dropping the roll paper support shaft 4 passed through the core 6 into the notch 3 of the side plate 1. Subsequently, the damper plate 18 is rotated to the release position against the return force of the return spring 20, and the leading end of the drawn roll paper 5 is inserted between the guide roller 15 and the guide plate 14, and the thermal head 10. The roll paper 5 is set by returning the damper plate 18 to the set position by the return force of the return spring 20. Then, the roll paper 5 is pulled out by rotating the platen 11 counterclockwise. Desired data is printed on the drawn roll paper 5 by the thermal head 10, and a receipt is issued by cutting the printed roll paper 5 with the cutter 12.
[0007]
Here, the function of the damper device 16 is to balance the tension acting on the roll paper 5 when the roll paper 5 is pulled out to the thermal head 10 and the pressing force pressing the roll paper 5 with the damper roller 19. When the roll paper 5 is pressed and loosened by the damper roller 19 on the upstream side of the thermal head 10 and the roll paper 5 exceeding the loosened part is pulled out by the platen 11, the damper is resisted against the urging force of the return spring 20. By rotating the plate 18 in the clockwise direction, an increase in the tension of the roll paper 5 is suppressed. When the platen 11 stops, the damper plate 1 is returned to the set position by the return force of the return spring 20, and the damper roller 19 rolls the roll. By loosening the paper 5 again, the roll paper 5 is pulled upstream in the next printing. As there are no bets, in which abnormal tension on the roll paper 5 from being granted.
[0008]
[Problems to be solved by the invention]
In the conventional damper device 16, the lower surface of the roll paper 5 is pressed by the guide roller 15, and the upper surface of the roll paper 5 is pressed by the damper roller 19 held by the damper plate 18 on the upstream side thereof, whereby the roll paper 5 is drawn out. It is a structure that refracts. For this reason, when setting the roll paper 5, the damper plate 18 must be retracted upward, and the roll paper 5 must be inserted between the guide plates 14 while maintaining the state, which is troublesome. Further, when an unfamiliar person operates, the roll paper 5 may be set without retracting the damper plate 18 upward. In such a case, since the roll paper 5 cannot be pressed by the damper roller 19, the function of the damper device 16 does not function at all.
[0009]
An object of the present invention is to enable roll paper to be set correctly and easily.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 is a roll paper support unit that rotatably supports roll paper, a roll paper transport unit that draws the roll paper from the roll paper support unit and supplies the roll paper to a print head, and the roll paper support unit And a cylindrical damper roller that is disposed in the roll paper drawing path between the print head and the roll paper and has a width substantially equal to the paper width of the roll paper, and the damper roller passes through the damper roller at the outer periphery of the damper roller. A tension coil spring stretched in a direction perpendicular to the drawing path so as to refract the drawing path of the roll paper, and the damper coil abuts against both ends of the damper roller on the outer periphery of the tension coil spring. A cylindrical member that restricts the axial movement of the roller is fitted.
[0011]
Therefore, it is possible to easily insert the roll paper from above the damper roller toward the print head. In this state, the damper roller pushes up the roll paper from the lower surface while bending the tension coil spring and refracts the drawing path of the roll paper, so that the roll paper can be loosened. Further, it is possible to absorb the increase in tension when pulling out the roll paper by the downward displacement operation of the damper roller.
[0012]
In addition, a cylindrical member that abuts both ends of the damper roller and restricts the axial movement of the damper roller is fitted to the outer periphery of the tension coil spring.
[0013]
Therefore, the center in the longitudinal direction of the damper roller can be matched with the center in the width direction of the roll paper.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. The same parts as those described with reference to FIG.
[0015]
The guide 13 is provided with a damper device 21. The damper device 21 includes a tension coil spring 22 stretched on both sides of the main frame 2 in a direction orthogonal to the drawing path of the roll paper 5, a cylindrical damper roller 23 penetrating the tension coil spring 22, And a cylindrical member 24 that passes through the tension coil spring 22 and restricts the axial movement of the damper roller 23. The inner diameter of the damper roller 23 and the cylindrical member 24 is set to a value slightly larger than the outer diameter of the tension coil spring 22, and the damper roller 23 is set to an outer diameter larger than the outer diameter of the cylindrical member. The tension coil spring 22 presses the damper roller 23 against the lower surface of the roll paper 5, and is stretched in a direction that refracts the drawing path of the roll paper 5 on the outer periphery of the damper roller 23. Further, on one side of the main frame 2, there is provided a drive gear 26 that transmits the rotation of a motor (not shown) to a gear 25 fixed to the end of the platen 11. The roll paper support shaft 4 is a roll paper support unit, and the platen 11 is a roll paper transport unit.
[0016]
In such a configuration, when the roll paper 5 is passed between the thermal head 10 and the platen 11, the roll paper 5 is inserted between the thermal head 10 and the platen 11 from above the damper roller 23. Therefore, the roll paper 5 can be easily set without moving the damper roller 23. When the roll paper 5 is set between the thermal head 10 and the platen 11 in this way, the drawing path of the roll paper 5 between the roll paper support shaft 4 and the thermal head 10 is refracted by the damper roller 23.
[0017]
The damper device 21 in the present embodiment also balances the tension acting on the roll paper 5 when the roll paper 5 is pulled out to the thermal head 10 and the pressing force for pressing the roll paper 5 with the damper roller 23. The roll paper 5 has a function of being pressed and loosened by the damper roller 23 on the upstream side of the thermal head 10.
[0018]
The state shown in FIG. 2 is a case where the tension applied to the roll paper 5 is as low as a certain value or less. In this case, the tension coil spring 22, the damper roller 23, and the cylindrical member 24 are arranged on substantially the same axis.
[0019]
By pulling out the roll paper 5 by rotating the platen 11, the damper roller 23 is pushed down by the roll paper 5 when the tension applied to the roll paper 5 is higher than a certain value. In this case, since the positions of both ends of the tension coil spring 22 are not changed, the cylindrical member 24 is inclined obliquely upward from the end of the damper roller 23 toward the end of the tension coil spring 22. At this time, it is possible to avoid a state in which abnormally high tension acts on the roll paper 5 by the operation of the damper roller 23 that descends while bending the tension coil spring 22. Therefore, during printing, the roll paper 5 on the thermal head 10 is not pulled upstream, thereby preventing the printing position from being disturbed.
[0020]
As described above, the damper roller 23 is displaced in the vertical direction while bending the tension coil spring 22 in accordance with the tension of the roll paper 5. However, since both ends are in contact with the cylindrical member 24, the damper roller 23 does not move in the axial direction. Absent. Thereby, the axial center of the damper roller 23 is always positioned at the center of the width direction of the roll paper 5, and the roll paper 5 can be supported without being biased.
[0021]
In the conventional example shown in FIG. 4, the guide roller 15 and the damper roller 19 that are arranged close to each other refract the drawing path of the roll paper 5 in the reverse direction. Will end up with a curl. On the other hand, in the configuration in the present embodiment, the drawing path of the roll paper 5 is merely refracted by the damper roller 23 at one place between the roll paper support shaft 4 and the thermal head 10. As a result, curling is difficult.
[0022]
Note that a roll paper transport unit for pulling out the roll paper 5 may be provided separately from the platen 11.
[0023]
【The invention's effect】
According to a first aspect of the present invention, there is provided a cylindrical damper roller disposed in a roll paper drawing path between the roll paper support portion and the print head and having substantially the same width as the paper width of the roll paper. Since the tension coil spring that penetrates the roller is stretched across the damper roller in a direction perpendicular to the drawing path so as to refract the drawing path of the roll paper, the roll paper is directed from the top of the damper roller toward the print head. It can be easily inserted. In this state, the damper roller pushes up the roll paper from the lower surface while deflecting the tension coil spring to refract the roll paper drawing path, so that the roll paper can be slackened, and the tension when pulling out the roll paper is increased. Can be absorbed by the downward displacement operation of the damper roller.
[0024]
In addition, a cylindrical member that abuts on both ends of the damper roller and restricts the axial movement of the damper roller is fitted to the outer periphery of the tension coil spring. It can coincide with the center in the width direction. Thereby, the axial center of the damper roller is always positioned at the center of the roll paper width direction, and the roll paper can be supported without being biased.
[Brief description of the drawings]
FIG. 1A is a perspective view of a receipt printer according to a first embodiment of the present invention, and FIG. 1B is an exploded perspective view showing a support structure of a damper roller.
FIG. 2 is a longitudinal front view of the receipt printer in a state where roll paper is set.
FIG. 3 is a longitudinal front view showing the operation of the damper device.
FIG. 4 is a longitudinal sectional front view showing a conventional receipt printer.
[Explanation of symbols]
4 Roll paper support unit 5 Roll paper 10 Print head 11 Roll paper transport unit 22 Tension coil spring 23 Damper roller 24 Cylindrical member

Claims (1)

A roll paper support unit that rotatably supports the roll paper, a roll paper transport unit that draws the roll paper from the roll paper support unit and supplies the roll paper to the print head, and between the roll paper support unit and the print head A cylindrical damper roller that is disposed in the roll paper drawing path and has substantially the same width as the roll paper, and passes through the damper roller and refracts the roll paper drawing path at the outer periphery of the damper roller. A tension coil spring stretched in a direction perpendicular to the pull-out path, and the outer periphery of the tension coil spring abuts both ends of the damper roller to restrict the axial movement of the damper roller. A receipt printer in which a cylindrical member is fitted .

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