JP3454227B2 - Roll paper slack prevention mechanism - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for preventing the slack of roll paper mounted on a facsimile, a printer or the like.

[0002]

2. Description of the Related Art Conventionally, in a means for preventing the slack of roll paper wound in a roll used in a printer or the like, it is necessary to prevent the slack of the roll paper which is inevitably caused by rotation or vibration of the roll paper. Therefore, it is one of the important factors to give a load to the roll paper by some method.

Here, FIG. 4B is a sectional view of a printer device having a conventional roll paper slack preventing mechanism.

For example, in the printer device disclosed in Japanese Utility Model Laid-Open No. 6-83349, as shown in FIG. 4B, the front panel portion 30 is opened in the direction of arrow B, and the heat-sensitive roll paper 28 is attached. By closing the front panel portion 30 in the direction of arrow C, the heat-sensitive roll paper 28 is moved to the main body 22.
At the same time as being accommodated in the roll paper accommodation space 64 inside, the flexible sheet material 52 whose upper end is fixed so as to hang down from the upper portion of the main body 22 is deformed along the outer periphery of the heat-sensitive roll paper 28. In this state, the thermal head 62 performs printing, and the feeding mechanism prints the thermosensitive roll paper 2
A device 8 is discharged from the roll paper discharge port 32.

In this apparatus, the heat-sensitive roll paper 2 is provided by the flexible sheet material 52 as a sagging prevention mechanism.
8 is applied so that the heat-sensitive roll paper 28 is prevented from sagging.

[0006]

However, this technique is intended only for rotation in the forward direction in which the roll paper is pulled out, and is characterized by constantly applying a load to the roll paper. It is effective when rotating in the forward direction, but when the roll paper rotates in the reverse direction, applying a load to the roll paper may cause slack to occur, This conventional technique has a problem of causing slack in a printer that requires rotation of the roll paper in both forward and reverse directions.

Further, in this technique, a method of setting the roll paper by throwing it from the upper part cannot be adopted due to the structure, and there is a problem in adapting to the simplification of the roll paper setting.

Further, as the roll paper becomes smaller, the load on the roll paper given by the flexible sheet becomes smaller and the sagging prevention effect becomes weaker.

In order to solve the above problems, an object of the present invention is to prevent the occurrence of slack in roll paper which is required to rotate in both forward and reverse directions, or to prevent the slack in roll paper. It is to provide a mechanism.

[0010]

In order to achieve the above object, a roll paper slack preventing mechanism according to the present invention includes a front roller which is two drive rollers for rotating the roll paper in a forward direction and a reverse direction. A rear roller is provided in parallel and rotatable. The roll paper is placed on the two rollers, and the outer circumference of the roll paper contacts the front roller and the rear roller. Therefore, when the front roller and the rear roller are rotated, the roll paper is rotated. Become. Further, the paper pulled out from the roll paper passes between the front roller and the rear roller, and is sandwiched between the first roller and the pusher roller installed at the front of the paper to be conveyed.

When the roll paper is rotated in the forward direction, the peripheral speed of the front roller is slightly lower than the peripheral speed of the rear roller, and when the roll paper is rotated in the opposite direction, the front roller and the rear roller are rotated. Make sure that the peripheral speeds of are equal.

With the above structure, when the roll paper is rotated in the forward direction, the slack generated in the roll paper can be eliminated by providing a difference in peripheral speed between the front roller and the rear roller.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

Here, FIG. 1 is a side view showing the structure of a roll paper slack preventing mechanism according to an embodiment of the present invention and the structure of a printer provided with this mechanism. In FIG. 1, the roll paper slack prevention mechanism according to the embodiment of the present invention includes a roll paper slack prevention mechanism and a thermal head 6.
, The platen 7 and the roll paper 1 are built in the printer.

As shown in FIG. 1, the roll paper slack preventing mechanism according to the embodiment of the present invention includes a rear roller 2, a front roller 3, a first roller 4, and a pusher roller 5.
It consists of and.

Here, the rear roller 2 and the front roller 3
Are rotatably provided parallel to the axial direction of the roll paper 1 with a distance shorter than the minimum diameter of the roll paper 1 being substantially horizontal to each other.

Further, the first roller 4 and the pusher roller 5
Is rotatably provided in parallel to the axial direction of the roll paper 1 and in a state of being close to each other.
The paper drawn from the roll paper 1 is sandwiched between the pusher roller 5 and the pusher roller 5, and the paper is sent to the thermal head 6 by the rotation of the first roller 4 and the pusher roller 5.

On the other hand, the roll paper 1 is just on the rear roller 2 and the front roller 3, and the paper pulled out from the roll paper 1 passes between the rear roller 2 and the front roller 3 to pass the first roller. Roller 4 and pusher roller 5
It is sandwiched between the platen 7 and the thermal head 6, and printing is performed.

Here, the direction in which the roll paper is fed by rotating the roll paper is called the forward direction, and the direction in which the roll paper is rewound is called the reverse direction.

Further, not a whole roll paper but a part of one sheet wound around the roll paper is called a paper.

Further, the paper feeding direction means a direction in which the paper pulled out from the roll paper is conveyed to a printing device such as a thermal head.

The operation of the roll paper slack prevention mechanism according to the embodiment of the present invention will be briefly described.
The rear roller 2, the front roller 3, the first roller 4, and the platen 7 are respectively driven in the feeding direction when the A is rotated in the A direction, that is, the forward direction, and when it is rotated in the B direction, that is, the reverse direction.

(Function of the Present Invention) Next, the function of the present invention will be described in detail with reference to FIGS. 3a and 3b.

FIG. 3a shows the rear roller 2, the front roller 3, and the first roller 3 when the roll paper 1 is rotated in the forward direction.
It is a figure explaining movement of a roller 4. Further, FIG. 3B is a diagram for explaining the movement of the rear roller 2, the front roller 3, and the first roller 4 when the roll paper 1 is rotated in the opposite direction.

For the sake of explanation, it is assumed in both figures that the roll paper 1 is slackened.

Referring to FIG. 3a, when the roll paper 1 is rotated in the forward direction, the peripheral speed V2a of the front roller 3 is slower than the peripheral speed V1a of the rear roller 2, and the peripheral speed V3a of the first roller 4 is lower. Equal to the peripheral speed V1a of the rear roller 2,

[0027]

[Equation 1] V1a> V2a ... (1)

[0028]

[Formula 2] V1a = V3a ... (2) There is a relation that the above equation holds.

As a result, when the slack is generated in the roll paper 1, the outermost paper of the roll paper 1 located in the portion in contact with the rear roller 2 and the paper inside the slack are caused by the relationship of the formula 1. Slip occurs between the two and the slack can be absorbed.

Further, referring to FIG. 3b, when the roll paper 1 is rotated in the reverse direction, the peripheral speed V1b of the rear roller 2 is changed.
And the peripheral speed V2b of the front roller 3 and the peripheral speed V3b of the first roller 4 are equal,

[0031]

[Equation 3] V1b = V2b = V3b ... (3) There is a relation that the above equation holds.

As a result, it is possible to suppress the slack of the roll paper 1.

[0033]

EXAMPLES Next, as a preferred example of the present invention, means for satisfying the above-mentioned formula 1, formula 2, and formula 3, that is,
Means for varying only the peripheral speed of the front roller 3 when the roll paper 1 is rotated in the forward direction and in the reverse direction will be described in detail with reference to FIGS. 2a and 2b.

Here, FIG. 2a is a top view for explaining the details of the roll paper slack prevention mechanism according to the preferred embodiment of the present invention, and FIG. 2b is the roll paper slack according to the preferred embodiment of the present invention. It is a side view explaining the detail of a prevention mechanism.

Referring to FIGS. 2a and 2b, in the embodiment of the present invention, a motor 8 for driving the rollers and the drive from the motor 8 are rear roller 2, front roller 3, first roller 4, A belt 17 for transmitting to the platen 7 is provided, and a torque limiter gear 11 having 33 teeth and a front gear 15 having 31 teeth are provided on the front roller shaft.

On the other hand, the rear pulley 10 is mounted on the rear roller shaft.
On the first roller shaft, the first gear 12 having 31 teeth,
A first transmission gear 13 and a one-way gear 16 having 31 teeth are installed.

Further, a gear pulley 14 for transmitting the driving force to the first transmission gear 13 is provided.

Here, the torque limiter gear 11 on the front roller shaft slides when a certain torque is applied, and the one-way gear 16 on the first roller shaft unidirectionally (reverse direction). The drive is transmitted only in one direction, and the drive cannot be transmitted in the other direction (forward direction).

Next, the operating principle of the embodiment of the present invention will be described in detail.

The power transmitted from the motor 8 by the belt 17 is first transmitted to the rear roller 2 via the rear pulley 10 and the rear roller 2 is driven.

Here, in the case of the rear roller 2,
It rotates at the same peripheral speed in both forward and reverse rotation directions.

Regarding the first roller 4, the belt 17 drives the gear pulley 14 and is driven via the gear pulley 14 and the first transmission gear 13. Also in this case, the first roller 4 rotates at the same peripheral speed in both rotation directions.

Regarding the front roller 3, when the roll paper is driven in the forward direction, that is, the direction of arrow A, the first gear 12 and the torque limiter gear 1 installed on the first roller 4 are used.
The speed is reduced to 31/33 by 1 and the drive is transmitted.

In this case, since the one-way gear 16 on the other side of the first roller shaft is in the idling state due to the one-way effect, the drive is not transmitted to the front roller 3 via the one-way gear 16.

On the other hand, when driving in the reverse direction, that is, in the direction of arrow B, the one-way gear 16 locks, and the power is transmitted from the one-way gear 16 to the front gear 15. Therefore, the front roller 3 has a ratio of 1: 1. Drive is transmitted to.

At this time, the drive is about to be transmitted from the torque limiter gear 11 on one side of the front roller shaft to the first gear 12, but the angular velocity of the front roller 3 and the first
Since the angular velocities of the rollers 4 are equal and the number of teeth is different, slippage of the torque limiter gear 11 and tooth skipping are prevented.

As described above, according to the present invention, when the roll paper is rotated in the forward direction, the peripheral speed of the front roller can be made relatively slower than that of the rear roller.

Then, slippage can be caused between the outermost shell sheet of the roll sheet located in the portion in contact with the rear roller and the sheet inside it, and the slack can be eliminated by that amount.

(Other Embodiments) As another embodiment of the present invention, the torque limiter gear 11 having 29 teeth is provided on the front roller shaft, and the one-way gear 16 on the first roller transmits the drive. The direction is set to the forward direction.

With such a structure, with respect to the front roller 3, when the roll paper is driven in the reverse direction, that is, the direction of the arrow B, the first gear 12 and the torque limiter gear 11 installed on the first roller 4 are arranged. By 3 1/2
The drive is transmitted after being accelerated to a ratio of 9.

On the other hand, when driving in the forward direction, that is, in the direction of arrow A, the one-way gear 16 locks, and the power is transmitted from the one-way gear 16 to the front gear 15. Therefore, the front roller 3 has a ratio of 1: 1. The drive is transmitted to the torque limiter 11, and at this time, the torque limiter 11 slips.

As described above, according to the present invention, when the roll paper is rotated in the opposite direction, the front roller is
It is possible to rotate faster than the rear roller and the first roller, which have the same peripheral speed, and slip occurs between the outermost paper of the roll paper located in the part in contact with the rear roller and the paper inside it. The slack can be eliminated by that amount.

According to the present invention having the above-mentioned structure, the peripheral speed of the front roller can be varied depending on whether the roll paper is rotated in the forward direction or in the reverse direction. It is possible to relatively change the peripheral speeds of the front roller and the rear roller.

Further, the present invention is not limited to the above-described respective embodiments or examples, and it is apparent that the respective embodiments or examples can be appropriately modified within the scope of the technical idea of the present invention.

[0055]

As described above, according to the present invention,
In an operation in which the roll paper alternately rotates in the forward direction and the reverse direction, it is possible to eliminate the slack occurring in the roll paper every time the roll paper rotates, so that the occurrence of the slack is eliminated, or Accumulation of slack can be eliminated, and troubles such as roll paper rotation due to slack can be prevented.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a roll paper slack preventing mechanism and a configuration of a printer including the mechanism according to an embodiment of the present invention.

FIG. 2A is a top view illustrating details of a roll paper slack preventing mechanism according to a preferred embodiment of the present invention,
FIG. 6B is a side view illustrating the details of the roll paper slack preventing mechanism according to the preferred embodiment of the present invention.

FIG. 3A is a diagram for explaining the rotation directions of the rear roller, the front roller, and the first roller when the roll paper is rotated in the forward direction, and FIG. 3B is the view in which the roll paper is rotated in the reverse direction. It is a figure explaining the rotation direction of the rear roller, the front roller, and the 1st roller at the time of making it.

FIG. 4A is a side view for explaining a conventional roll paper slack prevention mechanism, and FIG. 4B is a side view for explaining a conventional roll paper slack prevention mechanism.

[Explanation of symbols]

1 roll paper 2 rear roller 3 front roller 4 first roller 5 pusher roller 6 thermal head 7 Platen 8 motor 10 rear pulley 11 Torque limiter gear 12 1st gear 13 First transmission gear 14 gear pulley 15 front gear 16 one-way gear 17 Belt

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65H 23/182 B41J 15/16

Claims (2)

(57) [Claims] 1. A pair of rear rows, which are rotatably provided below the set roll paper and in contact with a part of the outer peripheral surface of the roll paper, in parallel with the axial direction of the roll paper. and a front roller, and the roll paper, which is provided downstream of the roll paper in the paper feeding direction.
A first roller and a second roller that sandwich and feed the sheet pulled out from the sheet ; at least the rear roller; the front roller;
A drive device that drives the first roller , wherein the rear roller is provided with respect to the front roller.
Provided downstream in the forward direction where roll paper is rotated and fed
It is, straddle over the Riarora and the front roller
The paper pulled out from the roll paper placed as
The drive device has a belt for transmitting the drive , passing through between the rear roller and the front roller, and the belt includes the belt and the rear roller via a predetermined pulley.
The belt is rotated at the same circumferential speed in both the forward and reverse rotation directions, and the belt moves the first roller through a predetermined pulley.
Both the forward and reverse rotation directions are rotated at the same peripheral speed, and the first gear and the one-way gear having the same number of teeth are mounted on the first roller shaft.
The one-way gear is driven only in the reverse direction.
Motion is transmitted, and the number of teeth on the front roller shaft is larger than that of the first gear.
Torque limiter gear and the same teeth as the one-way gear
A number of front gears, the first gear meshing with the torque limiter gear,
The one-way gear meshes with the front gear, and when driving the roll paper in the forward direction, the first gear is used.
And the torque limiter gear reduces the speed.
Drive is transmitted to the front roller and the one-way gear
Is in the idling state, and when driving the roll paper in the opposite direction,
The gear locks, and the one-way gear
The power is transmitted to the front gear, and the fluorocarbon is used at a ratio of 1: 1.
Drive is transmitted to the tracker, and the torque limiter gear
When transmitting the drive from the above to the first gear,
If the limiter gear slips and the roll paper is rotated in the forward direction, the same peripheral speed
The rear roller and the first roller that rotate by
A roll paper slack prevention mechanism that relatively slows the peripheral speed of the front roller . 2. A pair of rear rows provided rotatably below the set roll paper and in contact with a part of the outer peripheral surface of the roll paper in parallel with the axial direction of the roll paper. and a front roller, and the roll paper, which is provided downstream of the roll paper in the paper feeding direction.
A first roller and a second roller that sandwich and feed the sheet pulled out from the sheet ; at least the rear roller; the front roller;
A drive device that drives the first roller , wherein the rear roller is provided with respect to the front roller.
Provided downstream in the forward direction where roll paper is rotated and fed
It is, straddle over the Riarora and the front roller
The paper pulled out from the roll paper placed as
The drive device has a belt for transmitting the drive , passing through between the rear roller and the front roller, and the belt includes the belt and the rear roller via a predetermined pulley.
The belt is rotated at the same circumferential speed in both the forward and reverse rotation directions, and the belt moves the first roller through a predetermined pulley.
Both the forward and reverse rotation directions are rotated at the same peripheral speed, and the first gear and the one-way gear having the same number of teeth are mounted on the first roller shaft.
The one-way gear is driven only in the forward direction.
Motion is transmitted and the number of teeth on the front roller shaft is smaller than that of the first gear.
Same as the one way gear, with no torque limiter gear
A front gear having a number of teeth, wherein the first gear meshes with the torque limiter gear,
Serial one-way gear meshes with previous SL front gear, when driving the roll paper in the reverse direction, the first formate
And is accelerated by the torque limiter gear and
Drive is transmitted to the front roller and the one-way gear
Is in the idling state, and when the roll paper is driven in the forward direction,
The gear locks, and the one-way gear
The power is transmitted to the front gear, and the fluorocarbon is used at a ratio of 1: 1.
Drive is transmitted to the tracker, and the torque limiter gear
When transmitting the drive from the above to the first gear,
When slipping occurs in the limiter gear and the roll paper is rotated in the opposite direction, the same peripheral speed
The rear roller and the first roller that rotate by
A roll paper slack prevention mechanism that relatively increases the peripheral speed of the front roller .