JPH05270084A - Printer - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to improve the positional accuracy of the paper guides 23 and 24 and the platen roller 1 and thereby prevent the skew of the paper. [Structure] Paper ejection guide 23 having abutting portion 23b
Is rotatably incorporated in the paper feed / discharge guide unit 30, and the paper guide for introduction 24 is connected to the paper guide for discharge 23. The paper guides 23, 24 are urged by a spring 26 to contact the contact portion 23b. Is brought into contact with the bearing 21 of the rotary shaft 1a of the platen roller 1 to directly position the paper guides 23 and 24 with respect to the platen roller 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer in which a paper conveying path for a platen roller is formed by a paper guide.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram showing a main part of a conventional thermal printer disclosed in, for example, Japanese Patent Laid-Open No. 2-136261. In the figure, 1 is a platen roller rotatably provided in the printer body, and 2 is a platen roller 1.
3 is a pinch roller which rotates in contact with and is a thermal head which can be brought into and out of contact with the platen roller 1, and 4 is an ink sheet which is fed between the platen roller 1 and the thermal head 3.

Reference numeral 5 denotes a paper cassette mounted on the printer main body, on which paper (not shown) is stacked, and 6 rotatably provided on the paper cassette 5 in the printer main body for feeding the paper in the paper cassette 5. The paper roller 7 is a paper feed / discharge guide unit that is fixed in the printer body and forms a paper transport path, and FIG. 6 is a perspective view thereof.

Reference numeral 8 denotes a frame of the printer body (not shown)
A pair of side plates, which are screwed to each other, 9 is attached between the pair of side plates 8, and is an introduction paper guide for guiding the paper fed from inside the paper cassette 5 to the platen roller 1.
The platen roller 1 is attached between the pair of side plates 8.
The paper feed guide 11 for guiding the paper fed back by means of a paper feed guide 11, which is mounted between the pair of side plates 8 and guides the paper discharged from the platen roller 1.

In the conventional thermal printer as described above, the paper guides 9, 10 and 11 are attached between the pair of side plates 8 to assemble the paper feed / discharge guide unit 7, and then the paper feed / discharge guide unit 7 is mounted on the printer. Built in the body.
At this time, the paper feeding / discharging guide unit 7 is screwed and fixed in accordance with the reference position of the frame. The platen roller 1 is also positioned and attached at a predetermined position on the frame. In this way, the positioning of the platen roller 1 and the paper feed / discharge guide unit 7 is performed via the frame.

[0006]

In the conventional thermal printer configured as described above, since the platen roller 1 and the paper feed / discharge guide unit 7 are positioned through the frame, the platen roller 1 and The positioning accuracy between the paper guides 9, 10 and 11 is low, and the platen roller 1 may be slightly inclined with respect to the paper guides 9, 10 and 11. Also, the positional relationship between the platen roller 1 and the platen roller 1 may change after the replacement. As described above, when the platen roller 1 is relatively inclined, there is a problem that the sheet is skewed and the printing quality is deteriorated. In order to prevent such skewing, the platen roller 1 and the paper feed / discharge guide unit 7
There is also a problem in that it has to be adjusted with respect to the reference position quite accurately, and it takes time to assemble.

The present invention has been made to solve the above problems, and can improve the positional accuracy of the paper guide and the platen roller without lowering the workability of assembly. Therefore, it is an object of the present invention to obtain a printer capable of preventing the sheet from skewing and improving the printing quality.

[0008]

In the printer according to the present invention, a paper guide having a contact portion is rotatably provided in the printer body, and the paper guide is urged by a spring to cause the contact portion to platen. It is adapted to be brought into contact with the bearing of the rotary shaft of the roller.

[0009]

According to the present invention, the paper guide is positioned directly with respect to the platen roller by bringing the contact portion of the paper guide into contact with the bearing of the rotary shaft of the platen roller.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a perspective view showing a main part of a thermal printer according to an embodiment of the present invention, FIG. 2 is a side view of FIG.
The same or corresponding parts as those in FIG. 6 are designated by the same reference numerals and the description thereof is omitted.

In the figure, reference numeral 21 denotes a bearing which is penetrated by the rotary shaft 1a of the platen roller 1. In this embodiment,
A head positioning device is used in which a contact portion (not shown) of the thermal head 3 contacts during printing. Reference numeral 22 is a pair of side plates screwed to a frame (not shown) in the printer body.

Reference numeral 23 denotes a discharge paper guide which is rotatably mounted around a support shaft (fulcrum) 23a engaging with the mortise 22a of the side plate 22 and which guides the paper discharged from the platen roller 1. The ejection paper guide 23 is
It has a contact portion 23b which is in contact with the (color). twenty four
Is a paper guide for introduction which is connected to the paper ejecting guide 23 via the connecting member 25 and guides the paper fed from the paper cassette 6 to the platen roller 1, and 26 is provided between the side plate 22 and the connecting member 25. Is pressed to urge the discharge paper guide 23 to rotate clockwise in FIG.
A spring for bringing the bearing 21 into contact with the bearing 21, 27 is a connecting member 25 and a spring 26.
Is a pin that penetrates through.

Reference numeral 28 denotes a paper guide for reverse feeding, which is mounted between the side plates 22 and guides the paper fed backward from the platen roller 1, and 29 is rotatably mounted between the side plates 22 about a support shaft 29a. This is a paper guide for path switching, and this paper guide 29 for path switching is the paper guide 24 for introduction.
To switch the paper path between introduction and reverse feeding. 30 is a pair of side plates 22 between the above paper guides 23,
This is a paper feed and discharge guide unit with 24, 28 and 29 attached. 1 and 2 show one side surface, the other side has the same structure.

In the thermal printer configured as described above, the side plate 22 is screwed to a predetermined position of the frame in the same manner as in the conventional example, so that the paper feed / discharge guide unit is provided.
30 is built into the printer body. The platen roller 1 is also attached to the frame in the same manner as in the conventional example.

However, in the paper feeding / discharging guide unit 30 of this embodiment, an assembly as shown in FIGS. 3 and 4, that is, an assembly in which the discharging paper guide 23 and the introducing paper guide 24 are combined is a spindle 23a. The contact portion 23b is pressed against the lower portion of the bearing 21 by the spring 26. Therefore, the ejecting and introducing paper guides 23, 24 are directly positioned on the rotary shaft 1a of the platen roller 1. Therefore, the platen roller 1
The positional accuracy of the discharge and introduction paper guides 23, 24 with respect to the sheet is improved, and skewing of the sheet is prevented. As a result, the incorporation of the paper feeding / discharging guide unit 30 can be simplified to some extent as compared with the related art.

The number and shape of the paper guides may be changed according to the structure of the printer and is not limited to the above embodiment. Further, in the above embodiment, the ejecting paper guide 23 is provided with the abutting portion 23b and the ejecting and introducing paper guides 23 and 24 are positioned. The paper guide may be provided with an abutting portion. Further, although the thermal printer is shown in the above embodiment, the present invention can be applied to other types of printers.

[0017]

As described above, in the printer of the present invention, the paper guide having the abutting portion is rotatably provided in the printer main body, and the paper guide is biased by the spring to move the abutting portion. Since it is brought into contact with the bearing of the rotary shaft of the platen roller, the paper guide is directly positioned with respect to the platen roller, thus improving the positional accuracy of the paper guide and the platen roller without lowering the workability of assembly. As a result, skewing of the paper can be prevented, and the printing quality can be improved.

[Brief description of drawings]

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

FIG. 2 is a side view of FIG.

3 is a plan view showing an assembly of the discharge and introduction paper guides of FIG. 1. FIG.

FIG. 4 is a side view of the assembly of FIG.

FIG. 5 is a configuration diagram showing an example of a conventional thermal printer.

6 is a perspective view showing the paper feed / discharge guide unit of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen roller 1a Rotational shaft 21 Bearing 23 Paper ejection guide 23b Abutting portion 24 Paper introduction guide 26 Spring

Claims (1)

[Claims] 1. A platen roller rotatably provided in the printer main body, a bearing penetrating the rotary shaft of the platen roller, and a rotatably provided inside the printer main body, A paper guide having a contact portion for contacting the bearing and forming a sheet conveyance path, and a spring for urging the paper guide in a direction in which the contact portion contacts the bearing. A printer characterized by.