JP2001219631A - Ink ribbon guide mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink ribbon guide mechanism capable of preventing the oblique transfer of an ink ribbon by concentrating the tension of the ink ribbon, which is applied in the arraying direction of heat generating elements of a thermal head, at the central part in the arraying direction. SOLUTION: The ink ribbon guide mechanism is provided with a guide unit located in a section, orthogonal to the transfer direction of the ink ribbon, and formed so that the site of sliding contact with the running ink ribbon at the central part of arraying direction of the heat generating elements of the thermal head is projected while having the shape of a curved line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon guide mechanism, and more particularly to an ink ribbon guide mechanism capable of preventing skewed conveyance of an ink ribbon used for recording and performing good winding. .

[0002]

2. Description of the Related Art In general, a recording paper and an ink ribbon coated with a desired ink are supported in front of a platen, and a thermal head in which a plurality of heating elements as a recording head are arranged and arranged. While moving along the platen together with the carriage, the heating elements arranged in the thermal head are selectively heated based on the recording information to transfer the ink of the ink ribbon, and to print desired characters and the like on paper. A thermal transfer printer that records images
Because of high printing quality, low noise, low cost, and ease of maintenance, they are frequently used as output devices such as computers and word processors.

A ribbon cassette mounted on such a thermal transfer printer has a pair of rotatable reels in a main body case, and these reels are wound with ink ribbons from both ends. I have. When the ribbon cassette is mounted on the carriage of the thermal transfer printer, one of the reels is a supply reel that supplies the ink ribbon to a thermal head disposed downstream in the traveling direction, and the other is a portion used for recording. And a take-up reel for winding the ink ribbon.

A part of the ink ribbon is led out of the main body case in a ribbon traveling path between the supply reel and the take-up reel. When the is mounted on the carriage of the thermal transfer printer, the thermal head is arranged so as to face the paper via the ink ribbon.

FIG. 2 is an explanatory view showing a structure of a thermal head portion in the ink ribbon lead-out portion and a positional relationship of the ink ribbon, and FIG. 3 is a sectional view taken along line 3-3 in FIG.

[0006] A thermal head 11 of the printer is mounted on a carriage (not shown) reciprocally movable along a platen (not shown). The heating elements 13 are arranged on the upstream side in the ink ribbon transport direction of the thermal head. The heating element 13 is configured as a heating section that selectively generates heat based on desired recording information via a TAB 14 electrically connected to the thermal head 11.

On the downstream side (left side in the drawing) of the head mounting base 12 in the ink ribbon transport direction, a transport path for preventing the ink ribbon 15 from contacting the thermal head portion other than the heat generating portion, A guide portion 16 is formed for guiding the ink ribbon 15 after being provided for recording with the winding and conveying path. This guide part 1
6, as shown in FIG. 3, one top side 17 extending in the direction in which the heating elements 13 are arranged protrudes toward the ink ribbon contact surface side of the thermal head 11 from the heating section. When viewed from the downstream side in the transport direction of the ink ribbon 15 (when viewed from the viewpoint of the arrow in the figure), as shown in FIG. 4, the surface on which the heating element 13 of the thermal head 11 is formed (indicated by a dashed line in the figure). Is formed so as to draw a line parallel to the horizontal direction, and the running ink ribbon 14 is in sliding contact with the one top side 17 extending in the horizontal direction.

By the way, in order to obtain a good recorded image, it is essential to stably supply the ink ribbon 15 to the recording section.

For this reason, conventionally, for example, by providing a tension applying means between the supply side reel and the ink ribbon lead-out portion, a drawing load is applied to the ink ribbon 15 and the thermal head 11 Fifteen
In addition, when the ink ribbon 15 is pressed against the platen via the paper, an extra ink ribbon 15 is drawn out to prevent the ink ribbon 15 from being wrinkled or the like.

As the tension applying means, for example, a predetermined pull-out load (back tension) is applied to the ink ribbon 15 which is provided in the ink ribbon transport path in the ribbon cassette and is transported to the ink ribbon outlet. Supply pinch roller.

[0011]

The supply pinch roller rotates via a supply roller drive shaft formed on a carriage of the printer and fitted with the supply pinch roller. Was rotated by the driving force to rotate the roller, and depending on the state of the mechanism such as the runout accuracy of the supply pinch roller and the rotation unevenness of the gear system,
In some cases, the draw load changed, and the ink ribbon skewed and the ink ribbon 15 could not be stably conveyed.

When a thermal sublimation ink ribbon is used, since the recording energy supplied to the ink ribbon 15 is large, the ink ribbon 15 is damaged by the influence of the recording energy and the ink ribbon is displaced in the direction in which the heating elements are aligned. In some cases, a phenomenon called skew occurs, and the winding may not be stable.

The skew of the ink ribbon 15 is caused by the fact that the tension on either side of the ink ribbon 15 in the arrangement direction of the heating elements 13 is superior, and the ink ribbon 1
This is caused by the imbalance in the transport of the number 5.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned point, and it is an object of the present invention to prevent a skewed conveyance of an ink ribbon by collecting a tension applied in a direction in which the heating elements of the ink ribbon are arranged in a central portion in the arrangement direction. It is an object of the present invention to provide an ink ribbon guide mechanism which can perform the following.

[0015]

In order to achieve the above object, an ink ribbon guide mechanism according to the present invention is formed downstream of a thermal head provided on a printer carriage in the ink ribbon transport direction, and transports the ink ribbon. In the ink ribbon guide mechanism for guiding the ink ribbon, a portion where the running ink ribbon slides is formed in a curved shape in which a central portion in the alignment direction of the heating elements of the thermal head projects in a cross section perpendicular to the ink ribbon transport direction. It is characterized in that it has a guide portion, and the curved shape is an arc shape.

According to the ink ribbon guide mechanism of the present invention, a portion (surface) of the guide portion provided in the vicinity of the thermal head where the ink ribbon slidably contacts is curved such that the central portion of the heating element of the thermal head in the alignment direction projects. With such a configuration, the tension applied to the center of the ink ribbon in the arrangement direction of the heating elements can be higher than the tension applied to both ends thereof.

[0017]

FIG. 1 is an explanatory view showing the shape of a guide portion of an ink ribbon guide mechanism according to the present invention, and corresponds to FIG. 4 showing a conventional example. Note that the same components as those in the related art will be described with the same reference numerals.

As shown in FIG. 1, the guide portion 16 of the ink ribbon guide mechanism of the present invention is arranged such that the surface (site) 1 on which the running ink ribbon 15 slides is in the center of the thermal head 11 in the alignment direction of the heating elements 13. With a protruding curve,
Moreover, the sliding contact portion 1 is formed so as to protrude more toward the ink ribbon contact surface side of the thermal head 11 than the surface on which the heating element 13 is formed (indicated by a dashed line in the drawing). In the present embodiment, the ink ribbon 1
The sliding surface 5 of 5 is formed in an arc shape.

According to the ink ribbon guide mechanism of the present invention, the guide portion 16 disposed near the thermal head 11 is provided.
The surface 2 on which the ink ribbon 15 slides is formed in a curved shape in which the center in the alignment direction of the heating elements 13 of the thermal head 11 projects so that the tension applied to the center of the ink ribbon 15 in the arrangement direction of the heating elements 13 is formed. Can be higher than the tension applied to both ends.

With such a configuration, the ink ribbon 1
When a load is applied to the heating element 5, the tension at the center of the ink ribbon 15 located in the guide portion 16 in the arrangement direction of the heating elements 13 can be increased, so that the arrangement of the heating elements 13 is always provided on the ink ribbon 15. Since the force for concentrating at the center in the direction acts, it is difficult to skew. Therefore, it is possible to prevent the transport of the ink ribbon 15 from moving up and down in the arrangement direction of the heating elements 13.

By ensuring the stable conveyance of the ink ribbon 15 by applying the tension as described above, it is possible to obtain a good recording result and to eliminate the uneven winding of the ink ribbon 15.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified as needed.

[0023]

As described above, the ink ribbon guide mechanism according to the present invention can prevent the skew of the ink ribbon and can stably transport the ink ribbon, and can obtain a good recording result. And so on.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a positional relationship between a sliding portion of an ink ribbon of a guide member of an ink ribbon guide mechanism according to the present invention and an ink ribbon contact surface of a thermal head, as viewed from a transport direction of the ink ribbon.

FIG. 2 is an explanatory diagram showing a positional relationship between a conventional ink ribbon guide mechanism, a thermal head, and an ink ribbon.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is an explanatory diagram showing a positional relationship between an ink ribbon sliding portion of a guide member and an ink ribbon contact surface of a thermal head in the ink ribbon guide mechanism of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink ribbon sliding contact surface (part) (of guide part) 11 Thermal head 12 Head mount 13 Heating element 14 TAB 15 Ink ribbon 16 Guide part (of ink ribbon guide mechanism)

Claims (2)

[Claims] A thermal head provided on a carriage of the printer, the thermal head being formed on a downstream side in an ink ribbon transport direction;
An ink ribbon guide mechanism for guiding the transport of an ink ribbon, wherein a portion at which the running ink ribbon slides is curved at a cross section perpendicular to the ink ribbon transport direction, from which a central portion of a heating element of a thermal head in an alignment direction protrudes. An ink ribbon guide mechanism having a guide portion formed in a shape of a circle. 2. The ink ribbon guide mechanism according to claim 1, wherein the curved shape of the guide portion is a circular arc.