JPH10264487A - Ink ribbon cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink ribbon cassette especially useful as a both-sided print type in which the winding position of an ink ribbon on a winding core is corrected automatically. SOLUTION: A pair of rotatable cores are contained in a cassette body 10 and an ink ribbon 12 is wound between the cores wherein one core serves as a feeding core and the other core serves as a winding core. The ink ribbon 12 is led out to the outside of the cassette body 10 substantially in the center of the pass line thereof and the cassette body 10 is provided, at the front end part thereof, with a recess 13 to be fitted with a print head cooperating with the ink ribbon 12 being led out to print on a recording medium. A plurality of guide rollers 21-24, 31-34 are provided between the recess 13 and the feeding and winding cores. The guide roller 31 immediately in front of the winding core is inclined against a normal depending on the position for winding the ink ribbon. Preferably, the guide roller 31 is inclined vertically inward with respect to a normal in the range of 1-5 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink ribbon cassette mounted on a printer and used for printing on a predetermined recording medium in cooperation with a print head of the printer.

[0002]

2. Description of the Related Art Conventionally, a pair of rotatable cores are housed in a cassette body composed of a cover and a case, and an ink ribbon is wound between these cores, one of which is an unwinding core, and the other is a winding core. A known configuration of the ink ribbon cassette is known. In this ink ribbon cassette, the ink ribbon is led out of the cassette main body substantially at the middle of the pass line, and the front end of the cassette main body is printed on a recording medium in cooperation with the ink ribbon led out. A recess for inserting the head is provided. A plurality of guide rollers are provided between the recess and the unwinding core and the winding core, respectively.

[0003] In order to increase the pulling force of the ink ribbon mounted on the carriage of the printer and thereby improve the running stability of the ink ribbon, generally, an unwinding core and an ink ribbon wound around the unwinding core are used. A sheet made of a material having a large coefficient of friction is provided on the bottom surface of the cassette so as to contact the lower side surface.

[0004]

The guide rollers in the conventional ink ribbon cassette are all provided substantially vertically. In the ink ribbon cassette having such a configuration, the ink ribbon after the completion of printing of the entire winding is in a state of being concentrated and wound under the winding core by its own weight. If the core is mounted upside down after printing, it will be unevenly distributed upward from the center of the core.

[0005] For this reason, the ink ribbon cassette pulled out from the unwinding core (the winding core before being turned over) during backside printing cannot contact the sheet having a large friction coefficient, which may cause printing failure due to insufficient back tension. there were.

Further, if the ink ribbon is intensively wound on the lower portion of the winding before the printing of the entire winding is completed, the frictional contact with the sheet becomes excessive, which hinders the drawing of the ink ribbon. In some cases, printing of the whole volume became impossible.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems in the prior art, and has a pair of rotatable cores housed in a cassette body. An ink ribbon is wound between the cores, one is an unwinding core, the other is a winding core, and the ink ribbon is led out of the cassette main body substantially in the middle of the ink ribbon pass line. A concave portion for inserting a print head for printing on a recording medium in cooperation with the ink ribbon led out is provided at a front end portion of the cassette body, and the concave portion, the unwinding core and the winding core are provided with the concave portion. In the ink ribbon cassette in which a plurality of guide rollers are respectively provided between the guide rollers, the guide rollers immediately before the winding core are located at positions where the ink ribbon is to be wound. Flip and is inclined with respect to the vertical line, characterized in that provided.

[0008] Particularly preferably, the guide roller immediately before the winding core is provided such that its upper part is inclined inward in the range of 1 to 5 degrees with respect to the perpendicular.

[0009]

FIG. 1 shows an ink ribbon cassette 10 according to an embodiment of the present invention. The ink ribbon cassette 10 is of a double-sided printing type which can be mounted upside down from the state shown in the figure, and is therefore symmetrical in the drawing. Also,
FIG. 1 is a top view showing the ink ribbon cassette 10 in a state where a cover is removed from a cassette body formed by joining a case and a cover.

In the case 11, a pair of cores 20 and 30 around which the ink ribbon 12 is wound are accommodated. In the state shown in the drawing, the core 20 is an unwinding core and the core 30 is a winding core. . The ink ribbon 12 is guided from the unwinding core 20 by guide rollers 21, 22, 23, and 24, and furthermore, a substantially triangular protrusion formed on both sides of a concave portion 13 formed at the center of the front end of the case 10. After being guided to the tip of one of 25, 25,
3 is drawn out of the cassette. The other protrusion 3
The ink ribbon 12 guided by the leading end of the ink ribbon 5 and introduced again into the cassette is guided by the guide rollers 34, 33, 32 and 31 and wound around the winding core 30.

When the ink ribbon cassette 10 is loaded on a carriage of a thermal transfer printer, a pair of rotating shafts on the carriage are provided with an unwinding core 20 and a winding core 30.
To engage. Then, the rotating shaft inserted and engaged with the winding core 30 is rotationally driven by an appropriate drive source, so that the ink ribbon 12 passes from the unwinding core 20 to the winding core 30 through the above-described pass line. The take-up core 20 is also driven and rotated in the same direction as the rotation drive direction of the take-up core 30. Further, a thermal head provided so as to be able to reciprocate along the platen together with the carriage is inserted into a concave portion 13 formed at the center of the front end of the ink ribbon cassette 10, and moves upward in FIG. The portion of the ink ribbon 12 which is led out is pulled up, and a predetermined printing is performed on a predetermined recording medium conveyed in synchronization with the traveling of the ink ribbon 12.

Since the structure of the printer and the printing mechanism using the thermal transfer method are known, they are not shown in the drawings and will be described only briefly.

Of the guide rollers 21 to 24 on the winding side and the guide rollers 31 to 34 on the winding side, the guide roller 32 on the winding side is a drive roller. That is, a drive shaft (not shown) provided on the carriage while the ink ribbon cassette 10 is loaded on the carriage is engaged with the drive roller 32, and the drive shaft is rotationally driven by an appropriate drive source. When driven, the driving roller 32 receives the driving force and rotates in the counterclockwise direction in the figure, and actively assists the running of the ink ribbon.

On the other hand, the guide roller 22 provided on the unwinding side opposite to the guide roller 32 has a rotating shaft (see FIG. 1) rotatably provided on the carriage in a state where the ink ribbon cassette 10 is loaded on the carriage. (Not shown), but no drive source is connected to the rotating shaft, and the rotating shaft can only idle. In this embodiment, the guide roller 22 on the unwinding side is made of a low friction material (for example, ABS) having a friction coefficient of 0.2 to 0.8 with respect to the back coat (BC) surface of the ink ribbon 12. By being formed, the unwinding-side guide roller 22 is maintained in a stationary state without substantially rotating even while the ink ribbon 12 is running.

The other guide rollers 21, 23, 24 and 31, 33, 34 are rotatably provided, and the friction between the peripheral surface and the back coat surface of the ink ribbon 12 causes the ink ribbon 12 to travel. It rotates with it.

As shown in FIG. 2, the guide roller 31 immediately before the take-up core 30 is provided such that its upper part is inclined inward. The ink ribbon cassette is of a double-sided printing type as described above, and is used after being completely wound around the winding core 30 in the state of FIG. 2
0 is the winding core. Therefore, the guide roller 21 immediately before the winding core 20 at the time of printing on the back surface is also provided with its upper part inclined inward like the guide roller 31 (FIG. 3).

The operation of the guide roller 31 will be described below. When the ink ribbon 12 wound around the winding core 30 passes through the guide roller 31, a predetermined back tension is applied to the ink ribbon 12. Further, since the upper portion of the guide roller 31 is inclined inward, a force acts to raise the ink ribbon 12 along the guide roller 31, and this force acts on the ink ribbon 12.
Of the ink ribbon 12 in the winding core 30 is prevented from being excessively concentrated downward, and the winding at the proper position can be performed. .

The inclination angle θ of the guide rollers 21 and 31, that is, the angle between the axis X of the guide roller and the perpendicular Y is 1 to
It is within the range of 5 degrees. If the inclination angle is less than 1 degree, it is not possible to antagonize the weight of the ink ribbon 12, and the effect of correcting the winding position of the ink ribbon 12 becomes insufficient. When the inclination angle exceeds 5 degrees, the force for raising the ink ribbon 12 along the inclined guide roller becomes excessive due to the back tension on the ink ribbon 12, and the running stability of the ink ribbon 12 is hindered. I do.

As is well known, the guide rollers 21,
Reference numeral 31 is provided on the case 10 of the ink ribbon cassette and guides the travel of the ink ribbon 12 in pairs with guide rollers provided on a cover (not shown). Therefore, the guide rollers provided on the cover in pairs with the guide rollers 21 and 31 are also the guide rollers 21 and 31.
Similarly, it is provided to be inclined in the same direction.

Although the embodiment of the present invention has been described in detail above, the present invention is not limited to this embodiment, and various modifications can be made within the scope of the invention described in the claims.

For example, in the above embodiment, the guide roller 22 is made a stationary roller by setting the friction coefficient of the guide roller 22 to the ink ribbon BC surface within a predetermined range. It is also possible to configure so as to forcibly stop the rotation.

Depending on the type of the ink ribbon 12 to be used, the material and thickness of the sheet 14 may be appropriately selected even if the guide roller 22 is not a stationary roller and is configured to run idle when the ink ribbon runs. Thus, a predetermined back tension can be given in the entire winding range of the ink ribbon sheet 12 wound around the unwinding core 20.

[0023]

According to the ink ribbon cassette of the present invention, the winding position of the ink ribbon in the winding core is corrected, which is particularly useful when used as a double-sided printing type.

According to the present invention, the ink ribbon is wound up at an appropriate winding position by providing the guide roller immediately before the winding core with the upper portion inclined inward within a range of 1 to 5 degrees with respect to the perpendicular. The guide roller can be inclined at any angle in any direction to enable the ink ribbon to be wound at a desired position on the winding core without being limited thereto. .

[Brief description of the drawings]

FIG. 1 is a top view showing a state in which a cover of an ink ribbon cassette according to an embodiment of the present invention is removed.

FIG. 2 is a view showing an inclined state of a guide roller 31 in FIG.
It is an expanded sectional view by the A 'cutting line.

FIG. 3 shows a tilted state of the guide roller 21 in FIG.
It is an expanded sectional view by the B 'cutting line.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 ink ribbon cassette 11 case 12 ink ribbon 13 recess 20 unwinding core 21 to 24 guide roller (22 stationary roller) 30 winding core 31 to 34 guide roller (32 drive roller) θ inclination angle of guide rollers 21 and 31

Claims (2)

[Claims] A pair of rotatable cores are housed in a cassette body, and an ink ribbon is wound between these cores, one of which is an unwinding core and the other is a winding core. The ink ribbon is led out of the cassette body at substantially the middle of the cassette body, and a print head for printing on a recording medium is inserted into the front end portion of the cassette body in cooperation with the ink ribbon led out. In the ink ribbon cassette, a plurality of guide rollers are provided between the recess, the unwinding core, and the take-up core, respectively. An ink ribbon cassette provided to be inclined with respect to a vertical line according to a position to be wound. 2. The ink ribbon cassette according to claim 1, wherein the guide roller immediately before the winding core is provided with an upper portion inclined inward within a range of 1 to 5 degrees with respect to a vertical line.