JP2003146492A - Roll paper hold mechanism and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly carry roll paper to a printing position by small carrying force, and to prevent a bad influence caused by heat generation or the pressing when carrying the roll paper to the printing position from a roll paper storage part, in a throwing-in type roll paper hold mechanism. SOLUTION: This mechanism has the throwing-in type roll paper storage part storing the roll paper carried to the printing position; and a guide rail formed in an arc shape along the peripheral direction of the peripheral face of the roll paper stored inside the roll paper storage part, provided inside the roll paper storage part. A contact width size with the peripheral face of the roll paper in the direction along a rotation center direction of the roll paper in the guide rail is set to be not more than a prescribed size L1 not imparting a bad influence caused by friction resistance accompanying the contact upon the roll paper, and is set to be not less than a prescribed size L2 not imparting the bad influence caused by the heat generation or the pressing accompanying the contact upon the roll paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll paper holding mechanism and a printing device.

[0002]

2. Description of the Related Art Conventionally, a roll paper holding mechanism in a printing apparatus using roll paper is roughly classified into a shaft support type and a throwing type.

The shaft support type uses a roll paper having a paper core at the center, and the roll paper is held by inserting a holding shaft into the paper core. The roll paper holding mechanism is not in contact with the outer peripheral surface of the roll paper held in this manner.

On the other hand, in the throw-in type, roll paper is thrown into a roll paper storage portion having a substantially semi-cylindrical shape, and the outer peripheral surface of the roll paper is held in contact with the inner peripheral surface of the roll paper storage portion. The presence or absence of a paper core in the center of the roll paper does not matter.

Comparing the shaft support type roll paper holding mechanism with the throwing type roll paper holding mechanism, the shaft support type roll paper holding mechanism removes the paper core from the holding shaft every time the roll paper is replaced. It is necessary to insert the holding shaft into the paper core of a new roll paper, and it takes time to set the roll paper.

On the other hand, the throw-in type roll paper holding mechanism is easy to handle because the roll paper can be set only by throwing it into the roll paper storage portion. further,
Roll paper without a paper core can be used, and in that case, the paper core is excellent in that it does not remain as dust.

[0007]

FIG. 8 shows an example of a throw-in type roll paper holding mechanism. According to this roll paper holding mechanism, a roll paper storage unit 101 having a substantially semi-cylindrical shape is provided. The entire width L of the stored roll paper 102 along the rotation center direction of the roll paper 102 on the outer peripheral surface is in contact with the inner peripheral surface of the roll paper storage unit 101. Therefore, when pulling out the roll paper 102 stored in the roll paper storage unit 101 toward the printing position, a large frictional resistance is generated at the contact portion between the roll paper 102 and the roll paper storage unit 101, and the friction Due to the influence of the resistance, the conveyance state of the roll paper 102 toward the printing position is likely to vary, and the variation easily causes the print pitch to be disturbed.

In order to prevent such a print pitch disorder, it is necessary to stabilize the transport state of the roll paper 102 even if the frictional resistance between the roll paper 102 and the roll paper storage unit 101 becomes large. For that purpose, it is necessary to use a large-sized conveyance motor having a large output as the roll paper conveyance means for conveying the roll paper 102. However, when a large-sized carry motor having a large output is used, the entire printing apparatus including the carry motor becomes large, the cost becomes high, and the power consumption increases.

Another example of the throwing type roll paper holding mechanism is shown in FIG. According to this roll paper holding mechanism, an arc-shaped rib-shaped projection 103 protruding in a direction orthogonal to the rotation center direction of the roll paper 102 is formed on the inner peripheral surface portion of the roll paper storage unit 101, and this rib-shaped projection 103 is formed. Touches the outer peripheral surface of the roll paper 102 along the circumferential direction. Therefore, in this roll paper holding mechanism, the contact width dimension between the outer peripheral surface of the roll paper 102 and the rib-shaped projections 103 is reduced, the frictional resistance at the contact portion is reduced, and the roll paper 10 from the roll paper storage unit 101 is reduced.
2 can be carried smoothly. However, when such rib-shaped protrusions 103 are formed, a large pressing force is concentrated on the contact portions, and there is a problem that the roll paper 102 has stripes on the contact portions with the rib-shaped protrusions 103. . Further, when the roll paper 102 is a thermal paper, there is a problem that heat is generated due to the concentration of the pressing force at the contact portion between the rib-shaped projection 103 and the roll paper 102, and the contact portion develops color.

An object of the present invention is a throw-in type roll paper holding mechanism, which can smoothly carry a roll paper toward a printing position with a small carrying force, and which can be carried out from a roll paper storage portion to a printing position. It is an object of the present invention to provide a roll paper holding mechanism and a printing device that can prevent adverse effects due to pressing and heat generation when a roll paper is conveyed toward a sheet.

[0011]

A roll paper holding mechanism of the present invention is a throw-in type roll paper storage unit for storing roll paper conveyed toward a printing position, and a roll paper storage unit housed in the roll paper storage unit. A roll formed in an arc shape along the circumferential direction of the outer peripheral surface of the roll paper and provided in the roll paper storage portion, and the roll in the direction along the rotation center direction of the roll paper in the guide rail. The contact width dimension with the outer peripheral surface of the paper is equal to or less than a predetermined dimension L1 that does not have an adverse effect on the roll paper due to the frictional resistance associated with the roll paper, and the pressure applied to the roll paper due to the contact or It is set to be equal to or larger than a predetermined dimension L2 that does not have a bad influence due to heat generation.

Therefore, the contact width dimension of the guide rail with the outer peripheral surface of the roll paper in the direction along the rotation center direction of the roll paper does not adversely affect the roll paper due to the frictional resistance due to the contact thereof. Since it is the following, adverse effects due to frictional resistance due to the contact, for example, the roll paper cannot be conveyed, the print pitch is disturbed due to variations in the roll paper conveyance state, and the output of the drive motor for conveying the roll paper is kept low. It can be prevented. Further, the contact width dimension of the guide rail with the outer peripheral surface of the roll paper in the direction along the rotation center direction of the roll paper is not less than the predetermined dimension L2 which does not adversely affect the press or heat generation due to the contact with the roll paper. Therefore, adverse effects of pressure and heat generated due to the contact, for example, streak on the contact portion with respect to the roll paper is higher than the allowable state, or when the roll paper is thermal paper, color is generated more than the allowable state due to heat generation. Is prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. 1 is a perspective view showing the overall structure of the printer, FIG. 2 is a vertical sectional side view showing a roll paper holding mechanism, FIG. 3 is a vertical front view showing a roll paper holding mechanism, and FIG. 4 is a roll paper holding mechanism. It is a top view which shows the part of.

This printing apparatus is provided with an input operation section 1 equipped with a ten-key pad and various function keys at a position closest to the operator as viewed from the operator. A display unit 2 for displaying the contents input by keys and the like is provided, a printer unit 3 and a roll paper holding mechanism 4 are provided on the back side thereof, and a transparent detachable upper portion of the printer unit 3 and the roll paper holding mechanism 4 is provided. It is covered by the cover 5.

The roll paper holding mechanism 4 has a throw-in type roll paper storage portion 7 in which the roll paper 6 is stored. The roll paper storage portion 7 has an inner wall surface 8 recessed in a substantially semi-cylindrical shape.
have. At positions of both ends in the direction along the rotation center direction of the roll paper 6 stored in the roll paper storage unit 7, arc-shaped guides along the outer peripheral surface of the roll paper 6 stored in the roll paper storage unit 7 are provided. The rail 9 is formed.

The roll paper holding mechanism 4 is designed on the assumption that only the roll paper 6 having a predetermined width is used, and when the roll 6 having a predetermined width is stored in the roll paper storage portion 7, the guide rail 9 is provided. The contact width dimension of the roll paper 6 stored in the roll paper storage portion 7 with the outer peripheral surface is La on one end side of the roll paper 6 and Lb on the other end side thereof.
(However, La≈Lb).

The printer unit 3 holds the platen roller 10, a conveying motor (not shown) for rotating the platen roller 10, and the roll paper 6 which is brought into contact with the outer peripheral surface of the platen 10 and pulled out from the roll state. And a thermal head 11, which is a printing unit, for supplying the roll paper 6 that is pulled out from the roll state toward the print position by the platen roller 10, the transport roller, and the thermal head 11. Is configured. The transparent cover 5 has a roll paper discharge port 13 through which the roll paper 6 after printing is delivered.

Here, the contact width dimension between the guide rail 9 and the outer peripheral surface of the roll paper 6 stored in the roll paper storage portion 7 in the direction along the rotation center direction, and the roll paper 6 according to the contact width dimension. Experimental results of investigating the relationship with the withdrawal load (friction resistance) will be described based on the graph of FIG. It is assumed that the output of the carry motor that constitutes the roll paper carrying means 12 provided in the printer unit 3 is constant. As the contact width increases, the frictional resistance between the guide rail 9 and the roll paper 6 gradually increases, and the withdrawal load of the roll paper 6 also gradually increases. When the contact width becomes equal to or larger than the predetermined dimension L1, the drawing load of the roll paper 6 becomes the allowable value or more, the drawing state of the roll paper 6 varies, the print pitch is disturbed, and the roll paper 6 cannot be drawn out. Become.

Next, the contact width dimension between the guide rail 9 and the outer peripheral surface of the roll paper 6 stored in the roll paper storage portion 7 in the direction along the rotation center direction, and the roll paper 6 according to the contact width dimension. The experimental results of examining the degree of streaks and the degree of color development of the roll paper 6 when the thermal paper is used as the roll paper 6 will be described based on the graph of FIG. As the contact width becomes smaller, the appearance of streaks on the roll paper 6 and the color development become more noticeable, and the contact width becomes a predetermined dimension L.
When it is 2 or less, the amount of streaks and colors is more than the allowable value.

FIG. 7 is a graph in which the experimental results shown in FIG. 5 and the experimental results shown in FIG. 6 are summarized.
The contact width between the guide rail 9 and the outer peripheral surface of the roll paper 6 is L1.
By setting it to be L2 or more and L2 or more, it is possible to suppress the withdrawal load of the roll paper 6 to an allowable value or less, and to suppress the amount of streaks or colors to be an allowable value or less. The predetermined dimensions L1 and L2 of the contact width described above are the values of La + Lb shown in FIG.

In such a structure, the platen roller 10 is rotationally driven by driving the transport motor, and the roll paper 6 sandwiched between the platen roller 10 and the thermal head 11 is transported by the rotational force thereof, and the roll is rolled. A predetermined item is printed on the paper 6 by the thermal head 11, and the roll paper 6 for which printing has been completed is ejected from the roll paper ejection port 13.

Here, as shown in FIG. 7, the contact width dimension of the guide rail 9 with the outer peripheral surface of the roll paper 6 is L1.
By setting it to be L2 or more, the adverse effect due to the frictional resistance due to the contact with the roll paper 6, for example,
It is possible to prevent the print pitch from being disturbed and the roll paper 6 not to be conveyed due to variations in the conveyance state of the roll paper 6, and to adversely affect the pressure and heat generated when the roll paper 6 comes into contact with the roll paper 6, for example, the roll paper 6 is allowed. It is possible to prevent streaks of a value or more from being generated and the roll paper 6 which is a thermal paper from being colored more than an allowable value.

The contact width between the guide rail 9 and the roll paper 6 is (L1 + L2) / 2 + (L1-L2) / 1.
0 or less and (L1 + L2) / 2- (L1-L2) /
By setting the range to 10 or more, the guide rail 9
It is possible to more reliably prevent the adverse effect due to the frictional resistance caused by the contact of the outer peripheral surface of the roll paper 6 and the adverse effect due to the pressing or heat generation of the contact of the guide rail 9 with the outer peripheral surface of the roll paper 6.

Further, since the guide rails 9 are formed at positions where they abut on both ends of the outer peripheral surface of the roll paper 6 stored in the roll paper storage portion 7 in the direction of the center of rotation, the roll paper 6
It is possible to prevent skew when the sheet is conveyed toward the printing position and to convey the sheet in a stable manner.

[0025]

According to the roll paper holding mechanism of the present invention, adverse effects due to the frictional resistance caused by the contact between the guide rail and the outer peripheral surface of the roll paper, for example, the roll paper cannot be conveyed or the conveyance state of the roll paper varies. It is possible to prevent the print pitch from being disturbed while suppressing the output of the drive motor that conveys the roll paper to a low level.Furthermore, the adverse effects of pressing and heat generation due to the contact between the guide rail and the outer peripheral surface of the roll paper, for example,
It is possible to prevent the contact portion of the roll paper from being streaked more than the permissible state, and when the roll paper is heat-sensitive paper, it is possible to prevent the color from being developed more than the permissible state.

[Brief description of drawings]

FIG. 1 is a perspective view showing a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical sectional side view showing a roll paper holding mechanism.

FIG. 3 is a vertical sectional front view showing a roll paper holding mechanism.

FIG. 4 is a plan view showing a portion of a roll paper holding mechanism.

FIG. 5 is a graph showing an experimental result of the relationship between the contact width dimension between the guide rail and the outer peripheral surface of the roll paper stored in the roll paper storage portion and the roll paper pull-out load according to the contact width dimension. .

FIG. 6 shows an experiment result of a contact width dimension between the guide rail and the outer peripheral surface of the roll paper stored in the roll paper storage portion, and a degree of streak and color development on the roll paper according to the contact width dimension. It is a graph.

FIG. 7 is a graph showing the experimental results of FIG. 5 and the experimental results of FIG. 6 together.

FIG. 8 is an explanatory view showing a roll paper holding mechanism of a conventional example,
(A) is a vertical sectional front view, and (b) is a vertical sectional side view.

9A and 9B are explanatory views showing another conventional roll paper holding mechanism, in which FIG. 9A is a vertical sectional front view and FIG. 9B is a vertical sectional side view.

[Explanation of symbols]

4 Roll paper holding mechanism 6 roll paper 7 Roll paper storage 9 Guide rail 11 Printing section 12 Roll paper transport means

Claims (4)

[Claims] 1. A throwing type roll paper storage unit for storing roll paper conveyed toward a printing position, and an arc shape along the circumferential direction of the outer peripheral surface of the roll paper stored in the roll paper storage unit. And a guide rail provided inside the roll paper storage portion, and a contact width dimension with the outer peripheral surface of the roll paper in a direction along the rotation center direction of the roll paper in the guide rail is the roll. The predetermined dimension L1 or less that does not have an adverse effect on the paper due to the frictional resistance due to the contact, and
A roll paper holding mechanism that is set to a predetermined dimension L2 or more that does not adversely affect the pressure and heat generated by the contact with the roll paper. 2. The contact width dimension between the guide rail and the outer peripheral surface of the roll paper is (L1 + L2) / 2 + (L1-L).
2) / 10 or less and (L1 + L2) / 2- (L1-
The roll paper holding mechanism according to claim 1, wherein the roll paper holding mechanism is set to a range of L2) / 10 or more. 3. The guide rail is provided at a position where it abuts on both ends of the outer peripheral surface of the roll paper stored in the roll paper storage portion in the rotation center direction.
Roll paper holding mechanism described. 4. The roll paper holding mechanism according to claim 1, roll paper carrying means for carrying the roll paper held by the roll paper holding mechanism toward a printing position, and the roll. A printing unit that prints predetermined items at the printing position on the roll paper that is transported by the paper transport unit,
Printer having a.