JP2001026350A - Machine glazed paper feeding mechanism of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an almost constant back tension on a paper drawn out from a rolling part always even when the diameter of machine glazed paper is changed by a simple adjustment mechanism. SOLUTION: The position of a shaft 3a of a potentiometer 3 corresponding to the position of an arm 2 when machine glazed paper 1 with a fixed diameter is set, is determined to be a reference phase. When the diameter of the roll paper 1 is changed corresponding to the consumption of the roll paper 1, the arm 2 makes the angular changes around the shaft 3 of the potentiometer 3 and the phase of the shaft 3a of the potentiometer 3 is changed. Accordingly, the diameter of the roll paper 1 can be detected by the difference of the output voltage value of the potentiometer 3 and the voltage value of the potentiometer 3 when the shaft 3a of the potentiometer 3 is in the reference phase. The electric current corresponding to the diameter of the roll paper 1 is supplied to a motor connected to a gear so that a constant back tension is given always on the paper drawn out from the rolling part of the machine grazed paper 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll paper feed mechanism for a printer that uses roll paper as recording paper and that can reduce paper transport deviation regardless of the remaining amount of roll paper.

[0002]

2. Description of the Related Art In a printer using roll paper as a recording paper, an appropriate back tension (force in a direction opposite to the paper transport direction) is applied to the pulled paper in order to stabilize the running of the paper drawn from the roll. The paper is fed using a paper feed roller or the like while applying ()). In order to generate back tension, a force that regulates the paper drawer is applied to the roll part of the roll paper (the part where the paper is wound).
Given to. However, if the same force is always applied to the roll, the roll paper diameter becomes smaller and the back tension applied to the paper drawn from the roll becomes larger.

For example, when the amount of roll paper used is small and the roll paper diameter is large, the paper transport deviation is small, but the paper transport deviation increases as the roll paper diameter decreases as the roll paper is used. Appears. That is, when the roll paper diameter becomes small, the gap between lines in the print result increases, and the print quality deteriorates.

Therefore, various mechanisms have been proposed for adjusting the back tension applied to the pulled-out sheet in accordance with the change in the roll sheet diameter. For example, Japanese Utility Model 60-157
Japanese Patent No. 751 discloses an adjustment mechanism configured such that when a spring plate is applied to a roll portion and the roll paper diameter is reduced, the force applied by the spring plate to the roll portion is reduced.

Japanese Patent Laid-Open Publication No. Hei 8-164644 discloses a method of measuring the length of recording paper pulled out from a roll section and the amount of roll paper rotation, calculating the diameter of the roll paper from each measurement result, and calculating a back-up amount corresponding to the calculated amount. An adjusting mechanism for applying tension to a sheet is described. According to such an adjustment mechanism, the roll paper diameter can be grasped in accordance with the paper consumption amount, and an appropriate back tension can be applied to the paper drawn from the roll portion.

[0006]

However, in such an adjusting mechanism, a measuring means for measuring the drawing length of the recording paper, a measuring means for measuring the rotation amount of the roll paper, and a roll paper diameter based on each measurement result. Is an essential component. Therefore, it is suitable for application to an expensive printer using a wide recording paper, but cannot be applied to a general-purpose and relatively inexpensive printer because the adjustment mechanism becomes expensive.

An object of the present invention is to provide a roll paper feed mechanism of a printer capable of always applying a substantially constant back tension to the paper drawn from the roll section even if the roll paper diameter changes by a simple adjusting mechanism. With the goal.

[0008]

A roll paper feeding mechanism of a printer according to the present invention includes a roll paper diameter detecting means for detecting the diameter of a roll paper, and a force in accordance with a control command, the direction being opposite to the paper feeding direction. A tension applying means for applying a force to the roll paper; and a control means for outputting a control command corresponding to a detection value of the roll paper diameter detecting means to the tension applying means. And a roll paper diameter corresponding quantity output means for generating the detection value in accordance with the amount detected by the detection means.

In the roll paper feed mechanism, for example, the detecting means is an arm which always contacts the roll paper, and the roll paper diameter corresponding amount output means is a potentiometer which outputs a voltage value corresponding to the angle change of the arm. Is a configuration that is installed so as to be rotatable about the axis of the potentiometer. According to such a configuration, with a simple configuration, a mechanism for applying a substantially constant back tension to the sheet drawn from the roll unit is realized.

The control means outputs a control command for instructing a small force to the tension applying means when the roll paper diameter detecting means outputs a detection amount indicating that the roll paper diameter is small. Is configured to output a control command for instructing a large force to the tension applying means when outputting a detection amount indicating that the roll paper diameter is large.

The control means has a relationship between each output voltage value of the potentiometer and each control command amount to the tension applying means, and determines a control command amount to be given to the tension applying means from the relationship and the output of the potentiometer. It may be configured as follows. According to such a configuration, the control command amount can be immediately determined from the relationship between the preset output voltage value and the control command amount and the actual output voltage value of the potentiometer.

Preferably, the control means drives the tension applying means when the roll paper is running. In such a configuration, unnecessary power consumption is prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view showing an embodiment of a roll paper feeding mechanism of a printer according to the present invention as viewed from the side. FIG. 2 is an explanatory diagram illustrating a state in which the roll paper feeding mechanism of the printer is viewed from above. In the roll paper feed mechanism shown in FIGS. 1 and 2, the arm 2 is always in contact with the roll paper 1. The arm 2 can rotate around the axis 3a of the potentiometer 3. The roll paper 1 is fixed to a shaft 5 together with a gear 4. As shown in FIGS. 1 and 3, the gear 4 is meshed with a gear 6, and the gear 6 is a motor 7 (not shown in FIG. 1).
It is connected with the rotation axis.

The roll paper 1 passes through a pinch roller 8 and a platen 12 and passes through a paper feed roller 9 and a pressing roller 1.
It is sandwiched between zeros. The paper feed roller 9 includes a motor 11
Rotated by The thermal head 14 is moved up and down by the print head 13 at the place where the platen 12 is installed. During printing, the thermal head 14 presses the platen 12 and the thermal head 14
Melts ink on an ink ribbon (not shown), and roll paper 1 sandwiched between thermal head 14 and platen 12.
Transfer the ink to

FIG. 4 is a block diagram showing a control configuration example of the roll paper feeding mechanism. In the example shown in FIG. 4, at the time of printing, the control unit 21 drives the print head 13 up and down via the head position control circuit 22. Further, the motor 11 is driven via the paper feed motor drive circuit 23. And
A predetermined amount of current is supplied to the motor 7 via the tension motor drive circuit. Further, the output voltage of the potentiometer 3 is input to the control unit 21.

Next, the operation will be described. At the time of printing, the control unit 21 gives a head position control circuit 22 an instruction to move the print head 13 downward. The head position control circuit 22 moves the print head 13 so as to press the platen 12 according to the instruction. In that state,
Each predetermined pin of the thermal head 14 is energized. Then, the ink of the dots corresponding to the energized portions on the ink ribbon is melted and transferred to the paper being pulled out from the roll portion of the roll paper 1.

Next, the control section 21 gives a head position control circuit 22 an instruction to move the print head 13 upward,
A drive signal is given to the paper feed motor drive circuit 23 for a predetermined period. The predetermined period is a period corresponding to the sheet feeding period.
The paper feed motor drive circuit 23 controls the motor 1 in response to a command.
1 is driven. Therefore, the sheet pulled out from the roll unit moves by a predetermined amount in the direction a shown in FIG.

The diameter of the roll paper 1 and the shaft 3a of the potentiometer 3 are phase-matched in advance. For example,
The position of the shaft 3a of the potentiometer 3 according to the position of the arm 2 when the roll paper 1 having a predetermined diameter is set is set as the reference phase. When the diameter of the roll paper 1 changes according to the consumption of the roll paper 1, the arm 1 moves the shaft 3 a of the potentiometer 3.
The angle changes around. That is, the phase of the axis 3a of the potentiometer 3 changes. Therefore, since the output voltage of the potentiometer 3 changes according to the angle change, the output voltage value of the potentiometer 3 and the potentiometer 3
The diameter of the roll paper 1 can be detected from the difference from the voltage value of the potentiometer 3 when the axis 3a is in the reference phase.

As shown in FIG. 5, when the control unit 21 drives the motor 11 (signal c), it simultaneously supplies a current to the motor 7 via the tension motor drive circuit 24 (signal d). The driving direction of the motor 7 is opposite to the paper feeding direction of the roll paper 1 (direction b in FIG. 1), and the motor 7 applies a force in that direction via the gears 6 and 4 to the roll paper 1.
To communicate. As shown in FIG. 6, the amount A of current supplied to the motor 7 is large when the diameter of the roll paper 1 is large, and small when the diameter of the roll paper 1 is small.
The current change shown in FIG. 6 is set so that the back tension applied to the sheet drawn from the roll portion is always constant, but the current change for making the back tension constant is determined in advance by experiments or the like. .

When the diameter of the roll paper 1 is large, a relatively large force (force in the direction opposite to the rotation direction of the paper feed) is applied to the shaft 5, and when the diameter of the roll paper 1 is small, a small force is applied to the shaft 5. As a result, even if the diameter of the roll paper 1 changes, the back tension applied to the paper pulled out from the roll portion is kept substantially constant.

In the control section 21, for example, the amount of current supplied to the motor 7 in accordance with each output voltage value of the potentiometer 3 is set in advance in a table format or the like. Each supply current amount is a value corresponding to the diameter of the roll paper 1. Therefore,
The control unit 21 immediately determines the amount of current A to be supplied to the motor 7 based on the voltage value at that time output from the potentiometer 3 and the relationship between the preset output voltage value and the amount of supplied current. Can be.

When the paper feed for one line is completed, the control unit 2
1 stops the driving of the motor 11 and
Stop supplying current to Thereafter, the printing operation and the paper feeding operation are repeatedly performed until the printing process is completed.

As described above, according to this embodiment,
With the arm 2 always in contact with the roll paper 1, the position (phase) of the arm 2 according to the change in the roll paper diameter is detected as a phase change of the potentiometer 3. Then, in order to keep the back tension applied to the sheet pulled out from the roll section constant, a large force is applied to the roll section when the roll sheet diameter is large and small when the roll sheet diameter is small, according to the phase change of the potentiometer 3. Current is supplied to the motor 7 so that a force is applied to the roll.

Therefore, the mechanism is simplified as compared with a method of indirectly detecting the roll paper diameter such as calculating the roll paper diameter based on the roll paper consumption. Therefore, a roll paper feed mechanism that can prevent the paper conveyance deviation can be constructed at low cost. In addition, in this embodiment, since the roll paper diameter is directly detected, it is possible to deal with roll paper of various paper qualities as compared with the case of indirect detection. For example,
When calculating the roll paper diameter based on the roll paper consumption, the calculated roll paper diameter will be the same if the consumption is the same even if the paper thickness is different. However, when the paper thickness is different, the roll paper diameter should actually be different.

In this embodiment, the motor 7 serves as a tension applying means for applying a back tension to the paper.
Was used, but other means may be used. For example, a brake mechanism or the like may be used.

Further, as shown in FIG. 7, a control element for finely adjusting the back tension applied to the sheet drawn from the roll section may be provided. As described above, the amount of current supplied to the motor 7 in accordance with each output voltage value of the potentiometer 3 is set in the control unit 21 in advance in a table format or the like. The adjustment amount input unit 25 is for inputting a value for adjusting each supply current amount to the motor 7 which is set in advance, and is realized by, for example, keys and buttons provided in a printer. .

Although the back tension is always kept substantially constant by the above-described roll paper feeding mechanism, there is a possibility that the set back tension amount may deviate from an appropriate value due to a change with time of parts or the like. . Therefore, when a sheet conveyance shift occurs due to component deterioration or the like during operation of the printer, a maintenance person or the like inputs an adjustment amount from the adjustment amount input unit 25. For example, a value such as +1 or -1 is input. The control unit 21 increases the amount of current supplied to the motor 7 by +1 or decreases by -1 according to the input adjustment amount. Note that the input adjustment amount is stored in a nonvolatile memory or the like.

Further, a code for designating paper quality may be input as an adjustment value from the adjustment amount input section 25. For example, a code specifying a plurality of types of roll paper likely to be set in the printer can be input. In that case, the control unit 21 has each table in which the relationship between the output voltage value of the potentiometer 3 and the amount of current supplied to the motor 7 according to each type of roll paper is set. Then, the control unit 21 uses a table corresponding to the code input to the adjustment amount input unit 25 at the time of the back tension application control. Alternatively, when another code is input with respect to the amount of current supplied to the motor 7 based on the relationship corresponding to a certain code, the amount of current increased or decreased by a predetermined amount
May be configured to be supplied.

When such an adjustment amount input section 25 is provided, the back tension applied to the sheet pulled out from the roll sheet 1 can be set more appropriately. Note that the code input from the adjustment amount input unit 25 may be released to the user. Also, as a plurality of roll paper types that are likely to be set in the printer, for example,
General synthetic paper (or thermal paper), PET film,
Classification such as vinyl chloride film is performed.

As described above, the roll paper diameter detecting means for detecting the diameter of the roll paper, the tension applying means for applying a force to the roll paper in the direction opposite to the paper feeding direction according to the control command, Control means for outputting a control command corresponding to a detection value of the paper diameter detecting means to the tension applying means, wherein the roll paper diameter detecting means directly detects a change amount of the roll paper diameter, and a detection amount by the detecting means. In a roll paper feed mechanism of a printer having a roll paper diameter corresponding quantity output means for generating a detection value according to the control means, the control means determines a relationship between each output voltage value of the potentiometer and each control command amount to the tension applying means. Adjustment amount input means is further provided when the control command amount to be given to the tension applying means is determined from the relationship and the output of the potentiometer. If the control unit is configured to determine the control command amount according to the adjustment amount input from the adjustment amount input unit, even if the back tension amount becomes inappropriate due to component deterioration or the like. Further, even if different types of roll paper are set, adjustment can be made so that an appropriate back tension is given to the paper.

[0031]

According to the present invention, the roll paper feeding mechanism of the printer outputs a control command corresponding to the detection value of the roll paper diameter detecting means to the tension applying means to apply back tension to the paper, and Since the diameter detecting means has a detecting means for directly detecting a change amount of the roll paper diameter and a roll paper diameter corresponding amount output means for generating a detection value according to the detected amount by the detecting means, a simple adjusting mechanism is provided. Therefore, even if the roll paper diameter changes, almost constant back tension can always be applied to the paper drawn from the roll portion.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a state in which a roll paper feeding mechanism of a printer is viewed from a side.

FIG. 2 is an explanatory diagram illustrating a state in which a roll paper feeding mechanism of the printer is viewed from above.

FIG. 3 is a perspective view showing a roll paper portion.

FIG. 4 is a block diagram illustrating a control configuration example of a roll paper feeding mechanism.

FIG. 5 is a timing chart showing a driving example of a motor for feeding paper and a motor for generating back tension.

FIG. 6 is an explanatory diagram illustrating an example of a relationship between a roll paper diameter and a motor current.

FIG. 7 is a block diagram showing another control configuration example of the roll paper feeding mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roll paper 2 Arm 3 Potentiometer 4 Gear 5 Shaft 6 Gear 7 Motor 8 Pinch roller 9 Paper feed roller 10 Pressing roller 11 Motor 12 Platen 13 Printing head 14 Thermal head

Claims (5)

[Claims] 1. A roll paper feed mechanism for a printer using roll paper, comprising: a roll paper diameter detecting means for detecting the diameter of the roll paper; and a force in response to a control command and opposite to the paper feed direction. And a control means for outputting a control command corresponding to a detection value of the roll paper diameter detection means to the tension provision means, wherein the roll paper diameter detection means A roll paper feeding mechanism for a printer, comprising: a detection unit for directly detecting a change amount; and a roll paper diameter corresponding amount output unit for generating the detection value according to the detection amount by the detection unit. 2. The detecting means is an arm which always contacts the roll paper, and the roll paper diameter corresponding amount output means is a potentiometer for outputting a voltage value according to the angle change amount of the arm. 2. The roll paper feed mechanism for a printer according to claim 1, wherein the roll paper feed mechanism is rotatably installed as a center. 3. The control means outputs a control command for instructing a small force to the tension applying means when the roll paper diameter detection means outputs a detection amount indicating that the roll paper diameter is small, and outputs the roll paper diameter. 3. The roll paper feeding mechanism for a printer according to claim 1, wherein a control command for instructing a large force is output to the tension applying means when the detection means outputs a detection amount indicating that the roll paper diameter is large. 4. The control means has a relationship between each output voltage value of the potentiometer and each control command amount to the tension applying means, and determines a control command amount to be given to the tension applying means from the output of the potentiometer and the relationship. The roll paper feed mechanism of a printer according to claim 2 or 3, wherein the determination is made. 5. The roll paper feed mechanism of a printer according to claim 1, wherein the control means drives the tension applying means while the roll paper is running.