JPH05545A - Thermal printer - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] The present invention relates to a thermal printer, and an object of the present invention is to make a paper ejection guide portion, which serves as a guide for ejecting a paper, simple in structure and inexpensive, and to further improve performance. To improve. [Constitution] The eccentric cam 1 is provided only on one outer side of the pulley holder 7.
6 is fixed, and a roller 17 mounted on the arm 15 is mounted on the eccentric cam 16, and the elastic member 19 constantly applies a force to the eccentric cam 16. A shaft 18 to which a plurality of guides 14 are attached is fixed to the arm 15, and the shaft 18 is supported by the paper discharge guide 13. At the time of printing, the roller 17 is removed from the concave portion of the eccentric cam 16, so that the plurality of guides 14 do not contact the paper 9. Since the rollers 17 are located in the recesses of the eccentric cam 16 at the time of sheet feeding and sheet discharging, the plurality of guides 14 are arranged inside the sheet traveling surface of the drum 3. Therefore, the paper 9 can be reliably discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal printer having an improved paper discharge guide portion which serves as a guide for discharging paper.

[0002]

2. Description of the Related Art A conventional thermal printer is disclosed in Japanese Patent Laid-Open No. 01-
It is a paper discharge mechanism as described in No. 290470. That is, as shown in FIG. 4, two drums 3 provided on both sides of the platen 5 in the axial direction, and a plurality of drums 3 provided at predetermined intervals along the circumferential direction of the drum 3 are rotatably supported. A plurality of pulleys 6, two pulley holders 7 supporting the pulleys 6 and provided on both sides in the axial direction of the drum, and guided by the pulleys 6, the inner side of which is a part of the outer periphery of the drum 3 (hereinafter referred to as an opening And the endless belt 4 which is in close contact with the outer circumference of the drum 3 is held, and both side edges of the paper 9 are held by the drum 3 and the belt 4, and the drum 3 and the pulley holder 7 are held with the paper 9 wound around the drum 3. The paper 9 is rotated as a unit to move the paper 9 in one direction, and printing is performed by the thermal head 10 when the paper is moved. Color printing can be performed without reciprocating the paper 9 and high printing without color misregistration One in which there is an advantage that the quality can be obtained. When the paper 9 is wound around the drum 3 and when the paper is discharged from the drum 3, only the drum 3 is rotated, and the paper 3 is fed by the belt 3 driven by the rotation of the drum 3 and the drum 3. , I try to eject the paper. Further, 1 and 2 are paper feed guides, 11 is a registration roller, 12 is an idler registration roller, and 13 is a paper 9
Is a paper ejection guide when the paper is ejected from a state of being sandwiched by the drum 3 and the belt 4, and a push-up body 21 mounted on the paper ejection guide 13 is provided on the outside of the pulley holder 7 at the time of paper ejection. Since it is located in the notch of the member 23, the push-up body 21 is lowered by its own weight, and the paper discharge guide 13 rotates around the fixed part as a fulcrum so that it comes inside the surface of the drum 3 which is the paper running surface. ing.

[0003]

In the above-described conventional thermal printer, since the member having the notch is provided outside the two pulley holders provided on the outer side in the axial direction of the drum, the member having the notch. Must be circumferentially larger than the pulley holder. Further, since the push-up body extending to the paper discharge guide is attached to a member having a notch provided outside the two pulley holders,
Must be much longer than the width of the paper. Therefore, there is a problem that the shape and mounting space of each component become large. Further, when the paper is discharged, the paper discharge guide comes to the inside of the surface of the drum, which is the paper traveling surface, because the push-up body lowers due to its own weight in the notch of the member having the notch provided outside the pulley holder. Because of the structure, it is difficult to dispose the paper ejection guide and the pushing-up body, and there are problems that the number of parts is large and the cost is high. Further, since friction is constantly generated at the contact portion between the member having the cutout portion and the push-up body, depending on the material and surface finish of the member having the cutout portion and the push-up body, wear, scraps, noise, etc. Problems also occur.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a printer which has a simple structure and is inexpensive, which eliminates various obstacles caused by the paper ejection guide, reduces the space and improves the performance.

[0005]

The above object is to provide a plurality of guides provided with an eccentric cam having a recess at only one axially outer side of the pulley holder so as to come to the inside of the sheet running surface when the sheet is discharged. This is achieved by connecting the eccentric cam with an arm.

Further, by providing a roller at the contact portion between the eccentric cam and the arm, various problems occurring at the contact portion between the member having the notch and the push-up body can be solved.
Further, since the arm is pressed against the eccentric cam, that is, the drum center direction by the force of the elastic member, the performance is improved as compared with the conventional method of operating the paper ejection guide by its own weight.

[0007]

According to the present invention constructed as described above, the eccentric cam is mounted on one side of the pulley holder in the axial direction, and the concave portion of the eccentric cam is provided in the portion not corresponding to the belt, that is, the portion corresponding to the opening of the drum. Since it is arranged and fixed to the pulley holder, the pulley holder and the eccentric cam rotate at the same time during printing, the roller is pushed out of the concave portion of the eccentric cam, and the arm and the guide connected to the arm are also pushed up. Is located outside the paper running surface of the drum.

At the time of feeding and discharging, the roller and the arm are guided by the force of the elastic member to the concave portion of the eccentric cam, and the guide connected to the arm is also on the surface of the drum which is the paper traveling surface. It is placed inside. Therefore, the printed sheet can be reliably discharged.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing the embodiments. FIG. 1 is a perspective view showing an embodiment of the present invention. The plurality of guides 14 are fixed to a shaft 18, and the shaft 18 is supported by the paper discharge guide 13 and has a rotatable structure. The arm 15 is connected to one end of the shaft 18, and the roller 1 is attached to one end of the arm 15.
7 is attached. An elastic member 19 is attached to the other side of the arm 15 to press the arm 15 toward the center of the drum 3. An eccentric cam 16 is fixed to the outside of the pool holder 7 so that a concave portion is arranged at a position corresponding to the opening of the drum 3 where the belt 4 is not in close contact, and performs the same rotation operation as the pulley holder 7. . Since the roller is mounted on the eccentric cam 16, the pulley holder 7 rotates counterclockwise in the drawing during printing, and the roller 17 is disengaged from the recess of the eccentric cam 16 as shown in FIG. Since it is pushed, the guide 14 is also pushed up. That is, the guide 14 comes to be located outside the paper traveling surface. As a result, a plurality of guides 14
The leading edge does not come into contact with the paper 9, and the above-mentioned inconvenience is solved.

At the time of paper feeding and paper discharging, as shown in FIG. 2, the roller 17 rolls down into the concave portion of the eccentric cam 16 by the force of the elastic member 19, and accordingly the arm 15 and the guide 14 also follow, and the guide 14 is the drum. Since the sheet 9 is arranged inside the sheet traveling surface of sheet 3, the sheet 9 can be reliably discharged.
At this time, the eccentric cam 16 does not need a mounting space as wide as that of the conventional notch member 23, and may be provided only at one side. Further, the shaft 18 does not need to have the same length as that of the conventional push-up body 21, so that a small space can be realized. Further, the roller 17 is moved by the force of the elastic member 19 to the eccentric cam 1.
Unlike the conventional method using the self-weight, unlike the conventional method using the self-weight, the eccentric cam 16 does not jump up due to the surface of the eccentric cam 16 or any other load, and cannot be lowered in the concave portion, so that a stable movement can be obtained constantly. Since the roller 17 is used between the eccentric cam 16 and the arm 15,
There are no problems such as wear, scraps and noise due to friction.

[0011]

As described in detail above, according to the present invention, since the guide does not contact the paper at the time of printing, there is no possibility of causing print misalignment and paper jam, and the individual parts are miniaturized. The mounting space can be reduced.

Further, according to the present invention, the vertical movement of the guide is changed from the self-weight method to the spring force method, and the roller is used for the rotary contact portion, so that the performance can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a thermal printer of the present invention.

FIG. 2 is a side view of the thermal printer of the present invention during sheet feeding and sheet discharging.

FIG. 3 is a side view showing the thermal printer of the present invention during printing.

FIG. 4 is a side view showing an example of a conventional example.

[Explanation of symbols]

1, 2 are paper feed guides, 3 are drums, 4 are belts, 5 are platens, 6 is a pulley, 7 is a pulley holder, 8 is a pickup roller, 9 is paper, 10 is a thermal head, 11 is a registration roller, and 12 is an idler. Registration roller, 13
Is a paper ejection guide, 14 is a guide, 15 is an arm, 16 is an eccentric cam, 17 is a roller, 18 is a shaft, 19 is an elastic member, 20 is a paper feed cassette, 21 is a push-up body, 22 is a fixing member, and 23 is a cutting member. It is a missing member.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Yutaka Shoji, 1060 Takeda, Katsuta-shi, Ibaraki Hitachi Koki Co., Ltd. (72) Hiroshi Takahagi, 1060 Takeda, Katsuta-shi, Ibaraki Hitachi Koki Co., Ltd.

Claims (1)

Claim: What is claimed is: 1. A platen that extends in the axial direction facing the linear thermal head, two drums that are provided on both sides of the platen in the axial direction, and an outside of the drum in the axial direction. Two pulley holders provided, a plurality of belt instruction pulleys provided at predetermined intervals along the circumferential direction of the drum, and mounted on the pulley holder, and the inside of the pulley is guided by these pulleys, and the inside thereof is one of the outer circumferences of the drum. It is equipped with an endless belt that sticks to the outer circumference of the drum, leaving the part untouched, and the lower side of the opening of the drum where the belt is not in close contact at the time of paper feeding is positioned at the paper insertion port, and the drum and belt are rotated to move the paper from the lower side of the opening. Insert and rotate the drum and belt as a unit during printing to move the paper in one direction.When moving the paper, the paper is printed on the paper by the platen and thermal head. In a thermal printer that ejects paper from the upper side of the opening by rotating the drum and belt in the same direction as when the paper is fed, the tip is near the outlet. And a plurality of guides provided so as to be located radially inward of the outer circumference of the drum, a shaft for fixing the plurality of guides, and a notch at a portion corresponding to the position of the drum where the belt is not in close contact. An eccentric cam, a roller that is mounted on the eccentric cam and rotates following the rotation of the eccentric cam, an arm that holds the roller, and an arm and a roller that always press the eccentric cam toward the drum center. A thermal printer having an elastic member provided in the.