JPH08282073A - Ribbon changeover device of serial printer - Google Patents

Abstract

PURPOSE: To provide the ribbon changeover device of a serial printer preventing the rebound of a ribbon cassette generated at a time of color selection and capable of accurately setting a ribbon to a normal position at a time of the color changeover of the ribbon stably generating the force exceeding the friction of a printing head and the ribbon. CONSTITUTION: In a serial printer requiring the color changeover by a ribbon 8 having a plurality of colors, a cassette pressing lever 7 is provided to a printing head 1, a ribbon cassette 3 and a ribbon changeover device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon switching device for a serial printer.

[0002]

2. Description of the Related Art A ribbon switching device of a conventional serial printer is shown in FIG. 4, and it is generally a ribbon cassette 3 when a print head 1 and a tip arm 2 are integrated, and a ribbon cassette tilt for vertically moving the ribbon cassette 3. The ribbon cassette tilt adjusting mechanism 4 is configured to vertically move the ribbon cassette 3 and slide the ribbon 8 in contact with the print head 1 to switch the ribbon color.

[0003]

However, in such an apparatus, especially when the ribbon cassette is moved from the upper side to the lower side, the ribbon cassette itself has a mechanism for dropping the ribbon cassette, so that the ribbon cassette cannot be dropped. If the ribbon rebounds due to the recoil when it does, or if the friction between the print head and the ribbon is large, the ribbon may not fall completely, that is, the ribbon may not be set in the proper position. As a result, there has been a problem that mixed color printing or wrong color printing occurs. Therefore, the present invention solves such a problem, and its purpose is to prevent the rebound of the ribbon cassette which occurs at the time of color selection and to stably generate a force exceeding the friction between the print head and the ribbon. Another object of the present invention is to provide a ribbon switching device for a serial printer, which can set the ribbon accurately and in a proper position when the color of the ribbon is switched.

[0004]

SUMMARY OF THE INVENTION A ribbon switching device for a serial printer according to the present invention comprises a print head, a ribbon cassette for accommodating the ribbon, or a ribbon cassette for moving the ribbon cassette up and down. In the ribbon cassette tilt adjusting mechanism installed so as to switch between, the ribbon cassette is characterized by having a mechanism for constantly applying a force in a fixed direction.

[0005]

According to the above structure of the present invention, the position of the ribbon cassette is changed by the ribbon switching device, and the force for pressing the tip of the cassette pressing lever against the ribbon cassette by the compression spring is always exerted in a fixed direction. Therefore, it is possible to prevent rebound of the ribbon cassette, which occurs during color selection, mixed color printing or wrong color printing due to friction between the print head and the ribbon, and the ribbon can be set accurately and in a proper position when the color of the ribbon is changed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ribbon switching device for a serial printer of the present invention will be described with reference to the drawings.

FIG. 1A is a perspective view centering on the ribbon switching device of the serial printer of the present invention.
(B) is a side view as seen from the direction of the ribbon cassette tilt adjusting mechanism 4 for explaining the basic configuration. FIG. 2 is a side view for explaining the basic operation of the ribbon switching device of the serial printer of the present invention. FIG. 3 is a side view of a ribbon switching device for a serial printer according to another embodiment of the present invention in which a slope is installed on a ribbon cassette. FIG. 4 is a perspective view and a side view of a ribbon switching device of a conventional serial printer. FIG. 5 is a side view of another embodiment of the ribbon switching device of the serial printer of the present invention in which the cassette holder is mounted on the shaft. FIG. 6 is a side view of another embodiment of the ribbon switching device of the serial printer according to the present invention, in which the cassette retainer is implemented by a leaf spring.

As shown in FIG. 1, the ribbon cassette front end arm 2 is set on the print head 1. Since the ribbon cassette 3 and the ribbon cassette front end arm 2 are integrated, the upper and lower struts 5 of the ribbon cassette tilt adjusting mechanism 4 move up and down to set the left and right fulcrum shafts 6 of the ribbon cassette 4 as rotation fulcrums. The ribbon cassette front end arm 2 moves up and down. As a result, the built-in ribbon 8 having a plurality of colors moves up and down, and the position of the ribbon 8 with respect to the print head 1 shifts.

FIG. 2 is a side view for explaining the operation of the ribbon cassette 3 in more detail. FIG. 2A is a side view when the upper and lower columns 5 of the ribbon cassette tilt adjusting mechanism 4 are raised. The lifting force of the upper and lower columns 5 causes the ribbon cassette 3 to move upward and the ribbon cassette tip arm 2 to move. It will work in the opposite downward direction. 2B is a side view when the upper and lower columns 5 of the ribbon cassette tilt adjusting mechanism 4 are lowered, and when the upper and lower columns 5 of the ribbon cassette tilt adjusting mechanism 4 move downward, the action of the cassette pressing lever 7 and the ribbon The ribbon cassette 3 shifts downward due to the weight of the cassette 3, and at the same time, the ribbon cassette front end arm 2 shifts upward. Along with this, the built-in ribbon 8 is also shifted upward and the color switching of the ribbon is completed. The points at this time will be described with reference to the side view of FIG. The straight line connecting the contact point of the cassette case from the fulcrum of the cassette pressing lever 7 to the contact surface of the ribbon cassette 3 is shown in FIG. The angle must be on the + A side and not on the -A side. Furthermore, the further the distance B is, the greater the effect of the pressing action of the cassette becomes, and the angle is 90 °.
The closer it is to the degree, the higher the pressing force becomes, and more stable ribbon operation can be achieved.

FIG. 3 shows an example in which the slope 9 is installed in the cassette case 7 so that the cassette pressing force is not dispersed as much as possible, and the force of the cassette pressing lever 7 is lowered. Further, the grounding portion with the cassette is rounded to reduce the frictional force with the cassette.

FIG. 5 shows an embodiment using the cassette pressing shaft 11. The cassette pressing shaft 1 is compressed by the compression spring 10 passing through the cassette pressing shaft 11.
1 is pushed out and the lower surface side of the cassette 3 is pressed. FIG. 5A shows the cassette holding shaft 1 with respect to the slope 9.
1 is installed vertically. Furthermore, the tip of the shaft is made spherical to improve the sliding of the slope 9, and the force of the spring 10 acts directly on the tip of the shaft by using the presser foot as the shaft, which simplifies load calculation and actual load measurement. The advantages that
By horizontally installing the cassette pressing shaft 11 as shown in FIG. 5 (b), there is no oblique mold release in component manufacturing, and the mold structure by horizontal or vertical mold release simplifies the mold design and manufacture. It has the feature that

FIG. 6 shows an embodiment in which a leaf spring 12 is used as the presser foot. Since the leaf spring 12 is fixed by the screw 13, the pressing force can be changed by the bending amount, the plate thickness, the width, etc. of the leaf spring 12, which has the effect of simplifying the structure and workability of assembly. It becomes possible to raise. By implementing the above measures, the serial printer can be placed vertically, with the ribbon cassette set vertically.

[0013]

According to the present invention, even if the position of the ribbon cassette is changed by the ribbon switching device, a force is always applied to the ribbon cassette in a fixed direction. Prevents mixed-color printing and incorrect-color printing due to friction between the print head and the ribbon, so that the ribbon can be set accurately and in the correct position when the color of the ribbon is changed.

[Brief description of drawings]

FIG. 1 is a perspective view and a side view having a ribbon switching device of a serial printer of the present invention.

FIG. 2 is a side view having a ribbon switching device of the serial printer of the present invention.

FIG. 3 is a diagram showing another embodiment having a ribbon switching device of a serial printer of the present invention.

FIG. 4 is a diagram showing an example of a ribbon switching device of a conventional serial printer.

FIG. 5 is a diagram showing another embodiment having a ribbon switching device of a serial printer of the present invention.

FIG. 6 is a diagram showing another embodiment having a ribbon switching device of a serial printer of the present invention.

[Explanation of symbols]

 1 ... Print head 2 ... Ribbon cassette tip arm 3 ... Ribbon cassette 4 ... Ribbon cassette tilt adjusting mechanism 5 ... Cassette up / down moving column 6 ... Cassette fulcrum shaft 7 ... Cassette holder Lever 8 ... Ribbon 9 ... Slope 10 ... Spring 11 ... Cassette holding shaft 12 ... Leaf spring 13 ... Screw

Claims (3)

[Claims] 1. A print head, a ribbon cassette accommodating a ribbon, a ribbon cassette tilt adjusting mechanism installed so as to move the ribbon cassette up and down to switch the use position of the ribbon with respect to the print head, and the ribbon cassette. A ribbon switching device for a serial printer, comprising: a cassette pressing lever mechanism that constantly applies a force in a fixed direction. 2. The ribbon switching device for a serial printer according to claim 1, further comprising a cassette pressing shaft. 3. The ribbon switching device for a serial printer according to claim 1, further comprising a cassette pressing plate spring.