JPH0776443A - Paper roll holding device for printing device - Google Patents

Abstract

PURPOSE:To prevent rolled paper from being floated due to looseness of the rolled paper beforehand in a paper rolled holding mechanism for a printing device for recording information by feeding out the rolled paper. CONSTITUTION:In a printing device in which rolled paper 3 supported on at least one supporting roller 8 is fed out to supply the paper to a printing part, the supporting roller 8 is rotated drivingly in the direction opposite to the rotational feeding direction of the rolled paper 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for holding roll paper in a printing apparatus for feeding out roll paper and recording information.

[0002]

2. Description of the Related Art FIG. 4 is a side view showing an outline of a printing apparatus using roll paper. The rotational force of the motor M is transmitted to the platen P via the gears G1 ... G4, and when the platen P rotates, the continuous paper 2 sandwiched between the pinch roller 1 is pulled out from the roll paper 3 and supplied to the printing unit. Has been
Printing is performed with the thermal head H. Reference numerals 4 and 5 are paper guides.

FIG. 5 is a plan view and a side view of a conventional roll paper holding mechanism. Two receiving rollers 7 and 8 are rotatably arranged at the bottom of the roll paper receiving chamber 6 of the printing apparatus, and the roll paper 3 is placed thereon, so that the platen P and the pinch roller are arranged as described above. When the continuous paper 2 is sandwiched between the roll paper 3 and the paper 1, and the paper is pulled to the printing portion, the roll paper 3 receives the receiving rollers 7 and 8.
Is rotated with a light force and is paid out.

Below the roll paper 3, receiving rollers 7 and 8 are provided.
The lever 9 for detecting the near end of the roll paper 3 is supported by the shaft 10 at a position avoiding the above. Above the tip of the lever 9, an optical sensor 1 including a pair of a light emitting element and a light receiving element for detecting the position of the lever tip 9a.
1 is provided.

Although the lever 9 is pulled by the spring 12, it is normally pushed down by the weight of the roll paper 3, and the lever tip 9a is not detected by the optical sensor 11. However, when the roll paper 3 is consumed and the outer diameter becomes smaller and the weight becomes lighter as shown by the chain line, the spring 1
At 2, the lever 9 is gradually pulled up. When the lever tip 9a is detected by the optical sensor 11, the remaining amount of the roll paper 3 is small, so an alarm is issued by the signal output by the optical sensor 11 to notify the near end of the paper.

[0006]

When the roll paper 3 is loaded into the roll paper receiving chamber 6, it is not a problem if the roll paper 3 is sufficiently wound up, but normally the tip end is natural. It is loosened and put in a loose state. Once you have become accustomed to handling and learned the procedure, it is not so difficult to throw it in without loosening it, but usually it will easily loosen unless special care is taken.

Thus, when the roll paper 3 is thrown into the roll paper receiving chamber 6 in a loose state, the degree of freedom of the loose portion 3a increases as shown in FIG. The roll paper 3 shifts in the width direction, protrudes from the width W of the roll paper 3, and collides with both side walls 6a and 6b of the roll paper receiving chamber 6.

After the roll paper 3 is loaded into the roll paper receiving chamber 6, the roll tip 2 is moved by the platen P and the pinch roller 1.
6 is pulled by a force t, tension is applied on the back side of the roll paper 3 toward the platen P as shown in FIG. 6B, and the roll paper 3 is tightened, but the receiving roller 8 near the platen P and the feeding portion 2a During this period, no tension acts, so that the slack 3a accumulates only in this portion as shown in the figure. Moreover, even if the roll paper 3 is rotated and consumed, the slack does not disappear, and remains on the front upper side of the roll paper 3 forever.

As described above, since the loosened portion 3a sticks out on both sides and hits both walls 6a and 6b of the roll paper receiving chamber 6, the roll paper 3 is supported by the slack portion 3a. Become. If the slack section 3a does not occur,
Since the roll paper 3 does not partially hit both side walls and is in a free state, the roll paper 3 can be stably and smoothly rotated on the receiving rollers 7 and 8.

However, when the slack portion 3a acts as a support shaft for the roll paper 3 as described above, the feeding portion 2a at the leading end of the roll paper is pulled toward the platen P side,
The pulling force F in the direction of the arrow a ₁ acts on the roll paper 3, and the roll paper 3 floats up as a whole. This tendency becomes remarkable as the roll paper 3 is gradually consumed and becomes lighter.

In this way, the roll paper 3 receives the receiving roller 7,
When lifted from 8, the lever 9 for detecting the near end of the roll paper in FIG. 5 is pulled up by the tension spring 12, the lever tip 9a is detected by the optical sensor 11, and the near end signal is emitted. As a result, there is an inconvenience of causing a malfunction such as issuing a near-end signal although the device can still be used sufficiently.

Further, since the slack portion 3a is pressed against both side walls to prevent smooth and stable rotation of the roll paper 3, even if the platen P and the pinch roller 1 are pulled by a uniform force t, the roll paper 3 Since the rotation of No. 3 is unstable, the fixed amount of paper cannot be fed out, which causes a problem that the paper of a constant length cannot always be supplied.

Further, the slack portion 3a is provided in the roll paper receiving chamber 6
If the edge of the paper hits the inner wall of the paper and is damaged by being crushed or broken, the paper is cut after printing, and when the paper is handed to the customer as a receipt, the receipt paper is damaged and gives a bad impression to the customer.

The above-mentioned problems are likely to occur in a printing apparatus for POS and the like which uses a roll paper having a narrow paper width and a light weight.

A technical object of the present invention is to prevent the roll paper from being lifted up due to the slack of the roll paper which causes such a problem.

[0016]

According to the roll paper holding mechanism of claim 1, as illustrated in FIG. 1, the roll paper 3 supported on at least one receiving roller 8 is fed and supplied to the printing section. In the printing apparatus described above, the receiving roller 8 is configured to be rotationally driven in the direction opposite to the direction in which the roll paper 3 is delivered.

In the present specification, the "receiving roller 8
Rotates in the direction opposite to the direction in which the roll paper 3 is fed out. ”
And refers to the direction of rotation when viewed from the respective rotation centers. That is, when the roll paper 3 rotates clockwise, the receiving roller 8 rotates counterclockwise. Since the receiving roller 8 is driven so as to rotate in the reverse direction with respect to the roll paper 3, it is called a reverse rotation receiving roller.

According to a second aspect of the present invention, there is provided a roll paper holding mechanism.
The peripheral speed of the receiving roller 8 is rotationally driven so as to be higher than the peripheral speed of the roll paper 3.

According to a third aspect of the present invention, there is provided a roll paper holding mechanism.
The cross-sectional shape of the portion of the receiving roller 8 in contact with the roll paper 3 is a non-perfect circle with respect to its rotation axis.

[0020]

According to the present invention, since the receiving roller 8 supporting the roll paper 3 rotates in the direction opposite to the rotation direction of the roll paper 3, the contact surface between the receiving roller 8 and the roll paper 3 At, a force is generated to pull down the roll paper 3. That is, since a force f in the direction opposite to the force F for lifting the roll paper 3 is generated, even if the slack portion 3a is generated on the roll paper 3, it is possible to prevent the roll paper 3 from floating with the slack portion 3a as a fulcrum. It can be prevented.

When the peripheral speed of the receiving roller 8 is faster than the peripheral speed of the roll paper 3, the force in the direction of pulling down the roll paper 3 becomes strong. When the peripheral speed of the receiving roller 8 is faster than the peripheral speed of the roll paper 3, the pulling force t acting on the roll paper 3 from the platen P side becomes weak, and as a result, the force F in the pulling direction of the roll paper 3 also becomes weak. Therefore, the floating of the roll paper 3 can be reliably prevented.

When the pulling force t is weak, the supporting force acting on the slack portion 3a also decreases, so that the problem that the edge of the paper in the slack portion is crushed and damaged and the quality of the receipt paper is deteriorated is solved.

If the cross-sectional shape of the portion of the receiving roller 8 in contact with the roll paper 3 is a non-round circle, the roll paper 3 is periodically moved up and down by the rotation of the receiving roller 8. Vibrate. As a result, as indicated by the broken line in FIG. 2, even if the roll paper 3 is about to be pulled up with the slack portion 3a as a fulcrum, the vertical vibration force of the roll paper 3 itself cancels the pulling force F of the roll paper 3. Therefore, lifting is prevented. Moreover, due to this vertical vibration, the slack portion 3a also constantly moves up and down, and the contact pressure with the left and right wall portions 6a and 6b decreases, so that it is difficult to pull up.

Further, since the receiving roller 8 is not a perfect circle, the contact pressure between the receiving roller 8 and the roll paper 3 also periodically increases and decreases. When the contact pressure decreases, the slack portion 3a gradually moves toward the next receiving roller 7 side beyond the receiving roller 8 due to the rigidity of the sheet itself.

As a result, the slack of the roll paper is divided into two parts on both sides of the receiving roller 8 as a boundary, so that the feeding portion 2a is provided.
The force acting as a fulcrum by the slack portion 3a on the side is weakened, and in combination with the vertical vibration force of the roll paper 3, the floating of the roll paper 3 is more reliably prevented.

As described above, according to the first to third aspects, since the roll paper 3 is prevented from being lifted up, erroneous detection such as the alarm being activated before the roll paper reaches the near end is prevented. Further, it becomes possible to stably feed the paper in a fixed amount.

[0027]

EXAMPLES Next, examples of practical implementation of the roll paper holding mechanism in the printing apparatus according to the present invention will be described. FIG. 1 is a side view and a plan view showing an embodiment of claims 1 and 2. In this embodiment, the roll paper receiving chamber 6
Inside, two receiving rollers 7 and 8 are arranged, and the roll paper 3 is placed thereon. Then, the continuous paper 2 is sandwiched between the platen P and the pinch roller 1 and pulled by the force t, whereby the roll paper 3 is fed out and supplied to the printing unit.

As described above, when the roll paper 3 is loaded into the roll paper receiving chamber 6 in a loose state, the slack portion 3a is formed between the receiving roller 8 on the platen P side of the roll paper 3 and the feeding portion 2a. Occur. When the paper 2 at the leading end of the roll paper 3 receives the pulling force t from the platen P side, a force F for pulling up the roll paper 3 is generated with the slack portion 3a as a fulcrum.

In the present invention, one of the two receiving rollers 7 and 8 on the lower side of the roll paper 3 is located on the platen P side of the outer circumference of the roll paper 3 from the direction of the force F for lifting the roll paper 3 up. It is located at. The receiving roller 8 is connected to the drive source so as to rotate in the direction opposite to the rotation direction a ₂ of the roll paper 3 (direction a ₃ ). For example, it is connected to the motor M in FIG. 4 or a completely different drive motor via a clutch mechanism.

As described above, since the receiving roller 8 is driven to rotate in the opposite direction to the roll paper 3, the contact surface rotates in the same direction. The reverse rotation receiving roller 8 generates a force f in the direction of pulling down the roll paper 3, so that the pulling down force f is efficiently transmitted to the roll paper 3.
A material having a large frictional force such as rubber is suitable for the surface of the reverse rotation receiving roller 8, that is, the contact surface with the roll paper 3. Also, the surface may be roughened.

According to a second aspect of the present invention, in the roll paper holding mechanism as shown in the figure, the peripheral speed V2 of the receiving roller 8 is set to be higher than the peripheral speed V1 of the roll paper 3. Thus, when the peripheral speed V2 of the reverse rotation receiving roller 8 is faster than the peripheral speed V1 of the roll paper 3, the force f in the direction of pulling down the roll paper 3 becomes stronger.

In addition, when the peripheral speed V2 of the reverse rotation receiving roller 8 is faster than the peripheral speed V1 of the roll paper 3 and the overfeed state occurs, the pulling force t acting on the roll paper 3 from the platen P side becomes weaker. Force F for pulling up the paper 3
Is also weakened, and the roll paper 3 is hard to lift.

FIG. 2 is a side view and a plan view showing an embodiment of claim 3. In this embodiment, the reverse rotation receiving roller 8 has a non-perfect circle. Since the roll paper tip 2 is sandwiched between the platen P and the pinch roller 1 and pulled, the pulling force F acts while the roll paper 3 is constantly pressed against the receiving roller 8 on the platen P side. Since the receiving roller 8 that is pressed against is driven in a non-round state, the roll paper 3 vibrates up and down.

In the embodiment shown in FIG. 2, the reverse rotation receiving roller 8 has a cross-sectional shape obtained by cutting a part of a perfect circle into a flat shape, but various cross-sectional shapes as illustrated in FIG. 3 are applied. it can. The vertical vibration of the roll paper 3 varies depending on the sectional shape. In this figure, (a)-
In the case of (d), the roll paper 3 vibrates up and down once by one rotation of the reverse rotation receiving roller 8, whereas in the cases of (e) and (f), the roll paper 3 is rotated by one rotation of the reverse rotation receiving roller 8. Vibrates up and down twice. Similarly, in the case of (g), the roll paper 3 vertically vibrates three times, and in the case of (h), it vertically vibrates four times.

When the reverse rotation receiving roller 8 has a non-circular cross section as described above, not only the roll paper 3 can be vertically vibrated but also the protruding portion of the outer periphery of the receiving roller 8 is formed on the roll paper 3. Since the contact pressure at the time of contact is greater than that at the time of contact with the perfect circle, the force f in the pull-down direction can be more reliably achieved.
Can occur.

[0036]

According to the first aspect of the present invention, the receiving roller 8 supporting the roll paper 3 rotates in the opposite direction to the roll paper 3 and the force f in the direction of pulling down the roll paper 3 is generated.
Even if the slack portion 3a is generated, it is possible to prevent the roll paper 3 from floating around the slack portion 3a as a fulcrum.

According to the second aspect, since the peripheral speed of the receiving roller 8 is faster than the peripheral speed of the roll paper 3, the roll paper 3
The force in the direction of pulling down becomes stronger. In addition, the pulling force t that acts on the roll paper 3 from the printing unit side is weakened, and as a result, the force F for pulling up the roll paper 3 is also weakened, so that the roll paper 3 can be more reliably prevented from rising.

According to a third aspect of the present invention, the cross-sectional shape of the portion of the receiving roller 8 that contacts the roll paper 3 is a non-round shape, and the rotation of the receiving roller 8 causes the roll paper 3 to periodically vibrate vertically. Therefore, the pulling force F of the roll paper 3 is offset, and the vertical vibration also causes the slack portion 3a to constantly move up and down to reduce the contact pressure with the left and right wall portions 6a and 6b. To do.

As described above, according to the present invention, the roll paper 3
Even if a slack portion is formed, the roll paper 3 is prevented from floating up. Therefore, the problem that the roll paper 3 becomes lighter and the roll paper 3 floats up, and the near end detection of the roll paper malfunctions is solved. .

[Brief description of drawings]

1 is a side view and a plan view showing an embodiment of a roll paper holding mechanism according to claims 1 and 2;

2A and 2B are a side view and a plan view showing an embodiment of the roll paper holding mechanism of claim 3;

FIG. 3 is a side view illustrating various cross-sectional shapes of a reverse rotation receiving roller in the roll paper holding mechanism of claim 3;

FIG. 4 is a side view showing an outline of a printing apparatus using roll paper.

5A and 5B are a plan view and a side view of a conventional roll paper holding mechanism.

6A and 6B are a plan view and a side view for explaining the generation and function of a slack portion in a conventional roll paper holding mechanism.

[Explanation of symbols]

P Platen 1 Pinch roller 2 Continuous paper 2a Continuous paper feeding part 3 Roll paper 3a Roll paper slack part 3b Roll paper slack part pressure contact with side wall of roll paper receiving chamber 6 Roll paper receiving chamber 6a, 6b Roll paper receiving chamber Left and right walls of the chamber 7 Receiver roller 8 Platen side receiver roller F Force to pull up the roll paper f Force to pull down the roll paper t Force to pull the roll paper from the platen side 9 Near end detection lever 11 Optical sensor

Claims (3)

[Claims] 1. A printing apparatus in which a roll paper 3 supported on at least one receiving roller 8 is fed out and supplied to a printing unit, wherein the receiving roller 8 is reverse to a feeding rotation direction of the roll paper 3. A roll paper holding mechanism for a printing apparatus, wherein the roll paper holding mechanism is configured to be rotationally driven in a direction. 2. The roll paper of the printing apparatus according to claim 1, wherein the peripheral speed of the receiving roller 8 is rotationally driven so as to be higher than the peripheral speed of the roll paper 3. Retention mechanism. 3. The roll paper holder of a printing apparatus according to claim 1, wherein a cross-sectional shape of a portion of the receiving roller 8 which is in contact with the roll paper 3 is a non-perfect circle with respect to a rotation axis thereof. mechanism.