JPH08318653A - Printer - Google Patents

Abstract

PURPOSE: To provide a printer used in a small-sized terminal machine and stable in paper feed accuracy. CONSTITUTION: A printer has a paper feed mechanism constituted so that a pinch roller 25 is pressed to a paper feed roller 24 on the same line in the axial direction of the roller 24 by the winding spring different in a winding direction having shaft parts provided to both ends thereof and thermal paper 2 is held between both rollers 24, 25 to be fed out by the rotation of the paper feed roller 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device used for small terminals such as a handy terminal, a facsimile machine, and a measuring instrument.

[0002]

2. Description of the Related Art In recent years, miniaturization of terminal devices, measuring instruments and the like has been advanced, and accordingly, the printing device is required to have a simplified structure and parts (light, thin, small and small), low cost and to secure and improve printing accuracy. ing.

A conventional printing device will be described below.
5 and 6 show a conventional printing device. In FIG. 5, 1 is an integrated frame made of resin, 2 is a print head that is supported by a carriage 3, is pressed against the thermal paper 5 and the platen 6 by the pressing pressure of a head pressing spring 4, and receives the electric energy for printing. A carriage provided with a motor 8 for moving in the horizontal direction and a gear 9 for moving, 10 is a paper feed roller which rotates about a shaft 10a, 6 is a platen swingably supported by a platen holder 12, 5 is thermal paper, and 7 is pinch. A leaf spring, 11 is a sliding shaft of the carriage 3, 13 is a paper guide provided on the frame 1, and 14 is a rack which meshes with the moving gear 9 also provided on the frame 1.

Further, in FIG. 6, reference numeral 15 is a pinch roller supported and fixed by a leaf spring 16.

The operation of the conventional printing apparatus having the above structure will be described below. The thermal paper 5 is inserted from the rear of the paper guide portion 13, and the pinch leaf spring 7 supported and fixed to the frame 1 or the leaf spring 16 fixed to the frame 1 is inserted.
It is passed between the pinch roller 15 and the paper feed roller 10 supported by the platen holder 12, and is fed to the position of the platen 6 supported by the platen holder 12. A rotation signal is given to the motor 8 mounted on the carriage 3, the gear 9 directly connected to the motor 8 and the rack 14 are meshed, and the carriage 3 is moved rightward or leftward along the sliding shaft 11. At this time, by applying heat generation energy synchronized with the movement of the carriage 3 to the print head 2, the thermal paper 5 is colored to print dots, lines, characters and the like.

After printing, the carriage 3 is stopped, the paper feed motor is operated and the paper feed roller 10 is rotated through a transmission gear, and the required amount of the thermal paper 5 sandwiched by the pinch leaf spring 7 or the pinch roller 15 is fed out. Is.

[0007]

However, in the above-mentioned conventional configuration, the paper pressure is generated due to the variation in the pressing pressure of the pinch leaf spring 7 or the pinch roller 15 and the variation in the mounting position, and the accuracy of line feed, skew line feed, etc. It had a problem that it was bad.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a printing apparatus having a high line feed accuracy in which variations in the pressing pressure of the pinch roller and variations in the mounting position do not occur.

[0009]

In order to achieve this object, the printing apparatus of the present invention has different winding directions,
This is due to a configuration in which two pinch rollers each having a shaft whose winding end is linearly arranged outside the central axis of the winding are pressed against the paper feed roller.

[0010]

With this structure, it is possible to simplify parts and assembling work, reduce variations, and stabilize line feed accuracy.

[0011]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 are perspective views showing a printer according to a first embodiment of the present invention, a sectional view and a perspective view of a pinch roller. It is a figure. 1 to 3, reference numeral 20 denotes a frame made of synthetic resin having a bottom plate and side plates forming peripheral walls, and a paper guide 2 is provided from one side surface of the frame 20 to the inside.
1 is formed. A paper feed roller shaft 23 connected to a paper feed motor 22 is provided at a position corresponding to the paper guide 21.
The paper feed roller 24 attached to the is arranged. Further, a pinch roller 25, which is a winding spring formed by winding an elastic metal wire in a coil shape, is arranged at the terminal end of the paper guide 21 so as to be constantly in pressure contact with the paper feed roller 24.

As shown in FIG. 3, the pinch roller 25 is composed of a coil spring 25a wound in a coil shape and a shaft portion 25b, which is the central axis of the coil spring 25a, integrated at both ends thereof. One pair of two pieces constitutes one pinch roller 25, and one pair is attached so as to be pivotally supported by the paper guide 21 in different winding directions.

Further, the paper feed motor 22, the paper feed roller shaft 23, and the paper feed roller 24 constitute a paper feed mechanism, and the thermal paper 26 supplied along the paper guide 21 is fed out as necessary. ing.

A platen 28 attached to a platen holder 27 is provided on the delivery side of the thermal paper 26 by the paper feed mechanism, and the platen 28 slides along a slide shaft 29 attached to the frame 20. A print head 31 attached to the carriage 30 is in pressure contact with a head pressing spring 32.

A carriage motor 33 is mounted on the carriage 30, and a moving gear 34 driven by the rotational force of the carriage motor 33 meshes with a rack 35 formed integrally with the frame 20. The carriage 30 moves to the left and right around the sliding shaft 29 as a result of the rotation, and prints on the thermal paper 26 interposed between the platen 28 and the print head 31. This sliding shaft 29,
Carriage 30, carriage motor 33, moving gear 3
4, the rack 35 constitutes a carriage drive mechanism.

A flexible lead wire 36 for sending a signal from the outside is connected to the print head 31.

The operation of the printing apparatus constructed as above will be described. The thermal paper 26 is inserted from the rear of the paper guide 21 integrally formed with the frame 20, and the pinch roller 25 and the pinch roller 25 of the winding spring supported by the groove formed independently in a part of the paper guide 21 are pressed against each other. The platen holder 27.
It is sent to the position of the platen 28 which is swingably supported by. At this time, the shaft portion 25b of the pinch roller 25 is supported by the groove of the frame 20 and is constantly pressed against the paper feed roller 24, and the elasticity of the winding spring ensures that the pressing force against the paper feed roller 24 is always above a certain level.

Next, a rotation signal is applied to a carriage motor 33 mounted on the carriage 30, a moving gear 34 directly connected to the carriage motor 33 and a rack 35 integrally formed with the frame 20 are engaged, and the carriage 30 is moved to the frame 20.
It is moved to the right or left along the sliding shaft 29 fixed to the. In this state, heat-generating energy synchronized with the movement of the carriage 30 is applied to the print head 31, so that the thermal paper 26 is colored and dots, lines, characters, etc. can be printed.

After printing, the carriage 30 is stopped, the paper feed motor 22 is operated, and the rotation of the worm gear and roller gear fixed to the paper feed motor 22 is transmitted to the paper feed roller 2.
4 is rotated, the required amount of the thermal paper 26 sandwiched by the pinch roller 25 composed of two winding springs arranged in the same axial direction of the paper feed roller 24 and having different winding directions is fed out, and the printing operation is performed again. Texts, pictures, graphs, etc. can be printed by doing this. By setting the winding direction of the pinch roller 25 in the direction in which the thermal paper 26 is guided to the outside with respect to the rotation direction of the paper feed roller 24, the paper can be fed stably and accurately.

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows another embodiment of the pinch roller 25 using a winding spring in the printing apparatus described in the first embodiment of the present invention. In FIG. 4, 25 is a winding type pinch roller. The pinch roller 25 of this winding spring makes a winding from one side, and after winding a certain length to form the winding spring 25a, forms the linear shaft portion 25b. After that, a winding in the direction opposite to the winding start is performed for a certain length to form the winding spring 25a. The linear shaft portion 25b between the winding springs 25a is supported by the frame 20, and the winding springs 25a at both ends are pressed against the paper feeding roller 24 to form a paper feeding friction mechanism.

The operation is similar to that of the first embodiment and will not be described. With this structure, the pinch roller 25 is composed of a single coil spring, so that it is easy to assemble and is advantageous in terms of cost.

[0023]

As described above, according to the present invention, the pinch roller for pressing the heat-sensitive paper against the paper feed roller is constituted by the two pinch rollers having the central axis and having different winding directions. It is possible to realize an excellent printing device by reducing the load at the time of paper feeding and realizing stable paper feeding, reducing the number of parts, simplifying the assembly work, and reducing the cost.

[Brief description of drawings]

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

FIG. 2 is a side sectional view of a printing device according to an embodiment of the present invention.

FIG. 3 is a perspective view of a pinch roller using a wire spring according to the first embodiment of the present invention.

FIG. 4 is a perspective view of a pinch roller using a wire spring according to a second embodiment of the present invention.

FIG. 5 is a side sectional view of a conventional printing device.

FIG. 6 is a side sectional view of a conventional printing device.

[Explanation of symbols]

 20 Frame 21 Paper Guide 22 Paper Feed Motor 23 Paper Feed Roller Shaft 24 Paper Feed Roller 25 Pinch Roller 25a Winding Spring 25b Shaft 26 Heat Sensitive Paper 27 Platen Holder 28 Platen 29 Sliding Shaft 30 Carriage 31 Print Head 32 Head Pressing Spring 33 Carriage motor 34 Moving gear 35 Rack

Claims (3)

[Claims] 1. A frame having a bottom plate, a side plate, and a paper guide for guiding the paper, a pinch roller by a winding spring that presses against the paper feed roller against a part of the inner wall of the paper guide, and a paper feed mechanism for feeding the paper. And a carriage drive mechanism for moving the print head in the left-right direction. 2. The printer according to claim 1, wherein two winding springs having different winding directions are pressed against the paper feed roller to form a pinch roller. 3. The printing device according to claim 1, wherein the winding start and the winding end of the winding spring are linearly arranged in the axial direction of the shaft portion of the winding spring.