JPH06106895A - Tension mechanism in feeder for roll paper - Google Patents

Abstract

PURPOSE:To impart prescribed tension to the loose part of paper fed from a roll so as to surely prevent paper from running away during a high-speed feed. CONSTITUTION:A tension bar 21 is placed in the loose part 15a of paper fed from a roll. Both end parts of the bar 21 are held freely rotatably by a slider 22. The slider 22 is freely guided and held by guide rails 26 so as to be vertically moved. A pinion 20 provided in the tension bar 21 is engaged with a rack 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension mechanism of a roll paper feeder suitable for use in plotters, cutting plotters and the like.

[0002]

2. Description of the Related Art Conventionally, a grid rolling type plotter (a recording roller is held between a driving roller and a pinch roller,
A roll paper support means for stocking roll paper when a roll paper is used as a recording paper in a recording paper drive type plotter which drives the drive roller and moves the recording means in the vertical direction to perform desired recording. (Sending out) is provided, and the recording paper that has been recorded is separated (manual operation) when the drawing operation is completed. Further, in another conventional plotter, a roll paper support means for winding is provided on the opposite side of the recording unit, and the roll paper is fed out and loosened before recording as in the above apparatus. (Frame feeding), after the recording operation is completed, the recording paper having been recorded is wound by the winding-side roll paper supporting means.

In the case of the former plotter described above, since the delivery amount is performed in accordance with the user's eye amount, when the delivery amount is small, the amount of paper transported by the recording unit is equal to the amount of recording paper previously delivered. When it exceeds the limit, the stock roller applies a load to the recording paper in the direction opposite to the paper feed direction, which causes the recording paper and the rollers to slip in the recording paper holding section, making it impossible to perform accurate printing. Or, there is a problem that the recording paper is damaged. On the other hand, if the amount of feed is too large, the slack part of the recording paper contacts the ground and stains the recording surface, or if the recording paper is a cutting film, it may scratch or stain the film surface. As a result, there was a problem that the commercial value was lost.

In order to solve these problems, conventionally, like the latter device, the recording paper is fed out and loosened only in the recording range to be used in advance, and the recording paper is wound after the recording of the loosened portion is completed. And the amount of slack of the recording paper is set to the optimum value. When plotting with this plotter, most of the drawings are prescribed to have a predetermined size (A0, A1 size, etc.), so a frame feeding device was sufficient, but plotting with a nonstandard size In some cases, when cutting a long film used for a signboard or the like with a cutting plotter, the roll paper must be sequentially fed out and wound at the same time as the recording (cutting) amount.

Therefore, in the conventional apparatus, the transfer amount of the recording paper in the recording unit is calculated, and the drive unit of the roll supporting means is controlled accordingly, and the slack amount of the fed recording paper is always plotted. It was configured to have an optimum amount that does not affect the operation. However, the method of calculating the roll paper delivery amount and the winding amount based on the transfer amount of the recording paper by the recording unit as described above requires a very complicated control,
Usually, a method is used in which the amount of slack generated by feeding the recording paper is detected and the drive unit of the roll paper support means is controlled so that the amount of slack becomes constant.

Various methods for detecting the amount of slack have been proposed in the past. As an example, a vacuum chamber, which is usually used in a sprocket drum type plotter, is provided and air in the chamber is sucked. To loosen the recording paper (buffering),
A method in which the amount of slack is detected by a photo sensor or the like to control the roll paper supporting means (Japanese Patent Laid-Open No. 53-41132), a weight roll is placed on the slack portion of the recording paper, and the positions thereof are respectively a magnet and a proximity. A method (Japanese Patent Publication No. 48-36864) is known, which detects the upper and lower limits of a switch and the center opening / closing element for detecting the center position and controls the drive unit of the roll paper supporting means so that the slack amount becomes an optimum amount. Has been.

[0007]

However, the former vacuum suction method has a problem that it lacks versatility because it requires a large-scale device called a vacuum chamber and limits the width direction of the roll paper to be used. there were. On the other hand, the latter method of applying back tension to the slack portion of the roll paper using a weight roll has the advantage that the structure is simpler than the former and the tension of the roll paper can be made constant, but the roll paper can be used at high speed. When the paper is transported in the forward and reverse directions, the influence of inertia is large, causing "runaway recording paper". Therefore, if the weight roll is tilted in the vertical direction and the heights of both ends are different, the detection error of the sensor that detects the amount of slack However, there is a problem in that a malfunction occurs or a drawing error occurs. Also, since the rotation speed and torque of the motor are constant regardless of the slack amount, even if the slack amount is too small or too large,
When the motor suddenly rotates and reaches a predetermined amount of slack, the motor stops and the roll paper continues to rotate due to inertia, and the paper is continuously fed or wound until it stops. There is also a problem in that a deviation in drawing and a contact accident with the floor surface may occur due to the sudden movement and the feeding or winding of the paper after the stop.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to apply a predetermined tension to the slack portion of the roll paper and to roll paper. It is an object of the present invention to provide a tension mechanism of a roll paper feeding device capable of surely preventing "roughness of recording paper" when transferring paper at a high speed.

[0009]

In order to achieve the above object, a tension mechanism of a roll paper feeding device according to the present invention is placed on a slack portion fed from a roll paper and a predetermined tension is applied to the slack portion. A tension bar to be applied, a pair of sliders that rotatably hold both ends of the tension bar, a guide member that guides and holds the slider so that the slider can move up and down, and a rack in which a pinion provided on the tension bar meshes. Composed of.

[0010]

In the present invention, the pinions and racks provided at both ends of the tension bar maintain meshing relationship with each other even when the roll paper is transported at high speed, so that the pinions at both ends of the tension bar rotate in synchronization. Moreover, the tension bar is placed on the slack portion of the roll paper to give a certain back tension to the slack portion. This prevents the "ramp of recording paper" from being regulated.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a front view showing an embodiment in which a tension mechanism of a roll paper feeder according to the present invention is applied to a grit rolling type plotter, FIG. 2 is a side sectional view, and FIG. 3 is a perspective view of the tension mechanism. . In these figures, a grit rolling type plotter generally designated by reference numeral 1 has a required width, and a pair of columns 2a and 2b are erected at both ends of the upper surface, and a pair of front and rear ends are provided at both ends of the lower surface. A plotter provided with a movable mount 3 to which casters are attached, a recording pen 4, a pinch roller 5, a drive ρ etc. 6, a platen roller 7, a roll paper guide 8 and the like installed between the upper ends of the columns 2a and 2b. And a main body 9. Side plates 10A and 10B are provided opposite to the upper side surfaces of the columns 2a and 2b, respectively.
Roll paper 11 (11A, 11
Stock rollers 12A, 12 inserted through the central hole of B)
Bearing portions 13 each formed of a semicircular recess that rotatably supports the end portion of B and restricts the movement in the axial direction to axially support the same are formed. Also, the right side plate 1 facing the plotter 1
A pair of motors 14A and 14B for synchronously rotating both stock rollers 12A and 12B forward and backward are disposed on the inner surface of 0B. The rotation of each motor 14A, 14B is performed by a belt stretched between pulleys, each stock roller 12A, 1
Stock rollers 12A, 1 via a rotation transmission mechanism 17 including a gear that meshes with a gear attached to one end of 2B.
2B is transmitted. Therefore,
When the motors 14A and 14B are rotated in the forward and reverse directions, the roll paper 11A wound around the stock roller 12A is wound around the stock roller 12B, and the roll paper 11B wound around the stock roller 12B is moved around the stock roller 12B.
You can rewind to A.

The roll paper 11A fed from the stock roller 12A has a slack portion 15a by being slackened downward in a substantially U shape.
The roll paper 11B wound around B also has a slack portion 15b by being slackened downward in a substantially U shape. A predetermined tension is applied to the slack portions 15a and 15b by tension mechanisms 18 and 19, respectively.

The tension mechanism 18 of the roll paper 11A is
A tension bar 21 having a length longer than the width of the roll paper 11A and a pair of pinions 20 attached to both ends and placed on the slack portion 15a is provided.
Both ends of are inserted into the slider 22 and rotatably supported by bearings (not shown). In addition, the slider 22
A slider 24 that constitutes the position detecting means 23 (FIG. 3) of the tension bar 21 is disposed inside the.

Sensor bases 25, which are formed in a U-shape when viewed from the side, are provided near the lower rear surfaces of the columns 2a and 2b so as to correspond to the sliders 22, respectively. The sensor base 25 is provided with a pair of left and right guide rails 26 for guiding and holding the slider 22 movably in the vertical direction, and a rack 27 with which the pinion 20 meshes. Therefore, the tension bar 21 is held horizontally by being prevented from moving in the front-rear direction by the slider 22. Further, if the slider 22 does not move back and forth, the pinion 20 and the rack 27 always maintain the meshed state.
Even when the slack portion 15a of the roll paper 11A moves violently at the time of high-speed transfer of 1, the tension bar 21 does not tend in the vertical direction and maintains the horizontal state stably.

The sensor base 25 has the slider 2 attached thereto.
A linear potentiometer 28 that is long in the longitudinal direction is provided corresponding to the slider 24 that is provided in the inside of 2, and these constitute position detection means 23 that detects the position of the tension bar 21. .

The position detecting means 23 includes the motor 14
It is electrically connected to a control unit 30 that controls driving of A and 14B. The control unit 30 is arranged on the inner surface of the column 2a. The resistance value of the potentiometer 28 is the roll paper 11
According to the amount of slack in A, the tension bar 21
It changes as the sliding contact position of the slider 24 changes along with the vertical movement. In this case, the position detecting means 23 uses the slider 24.
Is set as a reference value (zero) when the potentiometer 28 is in contact with the center of the potentiometer 28, and when the output value of the potentiometer 28 is zero, no signal is sent to the control unit 30. 14 is stopped. When the amount of slack in the slack portion 15a of the roll paper 11A decreases and the tension bar 21 moves upward from the center of the potentiometer 28, the slider 24 also moves upward and the output value of the potentiometer 28 increases in the positive direction. The control unit 30 rotates the motor 14A in the forward direction based on the detection signal from the position detecting means 23 at that time. Therefore, the roll paper 11A of the stock roller 12A is fed out and the slack amount of the slack portion 15a increases, and when the slack amount increases, the tension bar 21 gradually descends, and when the slack amount reaches a predetermined slack amount, the output value of the potentiometer 28 is changed. It becomes zero and the driving of the motor 14A is stopped. On the other hand, the amount of slack in the slack portion 15a of the roll paper 11A increases, the tension bar 21 moves downward from the center of the potentiometer 28, and the output value of the potentiometer 28 increases in the negative direction. Based on the detection signal, the control unit 30 rotates the motor 14A in the direction opposite to the above. Therefore, the slack portion 15a of the roll paper 11A is gradually wound and reduced, and the tension bar 21 is gradually raised. Then, when the predetermined amount of slack is reached, the output value of the potentiometer 28 returns to zero and the driving of the motor 14A is stopped. As a result, the tension bar 21 is always located at the center of the potentiometer 28 and applies a predetermined amount of slack and a stable tension to the slack portion 15a.

The rotation speed and torque of the motor 14A are
The tension bar 21 increases proportionally in the direction away from the center of the potentiometer 28. In addition, the slider 22
An opening (not shown) is formed on the surface of the pinion 20 and the slider 24 facing the sensor base 25 so that the pinion 20 and the rack 27 can be engaged with each other and the slider 24 and the potentiometer 28 can be slidably contacted with each other. Correspondingly provided.

The tension mechanism 19 for applying a predetermined amount of slack and tension to the slack portion 15b of the roll paper 11B has the same structure as the tension mechanism 18 of the roll paper 11A described above. The same reference numerals are given and the description thereof is omitted. Further, the position detecting means 34 (FIG. 2) for detecting the position of the tension mechanism 19 is also configured in the same manner as the position detecting means 23, and therefore detailed description thereof will be omitted.

Although the above embodiment has been described for the case of being applied to the grit rolling type plotter, the present invention is not limited to this and can be applied to various plotters, cutting plotters and the like. Further, although the linear potentiometer is used as the position detecting means 23 and 34 in the above-described embodiment, a rotary potentiometer may be used to detect the position of the slider through a wire, or a motor with an encoder may be used. Further, in the above embodiment, the guide rail 26 that guides and holds the slider 22 so as to be movable in the vertical direction is configured as a guide bar. However, the present invention is not limited to this, and a rail structure is provided on the sensor base 25 so that the slider 22 is It may be slidable along the rail structure.

[0020]

As described above, in the tension mechanism of the roll paper feeding device according to the present invention, the tension bar is placed on the slack portion of the roll paper, and both ends of the tension bar can be freely rotated by the sliders which can move up and down. Since the pinion provided on the end of the tension bar is engaged with the rack, it is possible to apply a predetermined tension to the slack part of the roll paper without being limited by the width of the roll paper to be used. Also, stable tension can be applied even during high-speed recording (cutting), and “roughness of recording paper” can be suppressed. Therefore, stable drawing and cutting can be performed, and the reliability of the device can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a grit rolling type plotter including a tension mechanism of a roll paper supply device according to the present invention.

FIG. 2 is a side sectional view.

FIG. 3 is a perspective view of a tension mechanism.

[Explanation of symbols]

 3 Stand 9 Plotter body 11, 11A, 11B Roll paper 12A, 12B Stock rollers 15a, 15b Loose portion 18, 19 Tension mechanism 20 Pinion 21 Tension bar 22 Slider 23 Position detection means 26 Guide bar 27 Rack

Claims (1)

[Claims] 1. A tension bar placed on a slack portion unwound from a roll paper to apply a predetermined tension to the slack portion, a pair of sliders rotatably holding both ends of the tension bar, and a slider. A tension mechanism for a roll paper supply device, comprising: a guide member that guides and holds it so that it can move up and down; and a rack that a pinion provided on the tension bar meshes with.