JPH0712029Y2 - Ink ribbon switching mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an ink ribbon switching mechanism, and more particularly to an ink ribbon switching mechanism of a serial printer that can switch a printing color to a designated color by using a multicolor ink ribbon. Regarding

[Conventional technology]

A serial printer is used as an output device of an information processing system such as a personal computer or a word processor, and a CRT display device used as a display device of this information processing system has recently been a color CRT display capable of multicolor display. As devices have come to be used more and more, it has come to be desired that output printing can also be performed in multiple colors.

In order to satisfy such a demand, the same ink ribbon is divided into two layers or more vertically, and each layer is colored in different colors. Serial printers having an ink ribbon switching mechanism configured to print in a desired color by changing the mounting angle of the ribbon cassette with respect to the printing head have been widely used.

The conventional ink ribbon switching mechanism having the above-mentioned configuration rotatably supports the plate on the printer frame,
Fix the rod on which the ribbon mask is slidably mounted, and attach the ribbon cassette onto the plate.
There is used a means for positioning a desired color at a position corresponding to the print head by swinging the plate by a driving unit to change the mounting angle of the ribbon cassette with respect to the print head.

[Problems to be solved by the invention]

However, the above-mentioned conventional ink ribbon switching mechanism requires a plate, and since this plate corresponds to a ribbon cassette, it is large and heavy, and the cost is high. Further, the driving portion requires a large force, which is uneconomical, and further requires a space such as a plate portion, which causes a problem of downsizing.

The present invention has been made in view of the above-mentioned circumstances in the prior art, and the purpose thereof is to change the mounting angle of the ribbon cassette with respect to the print head without moving the plate, and also to move the ribbon mask up and down to move the ink ribbon. It is an object of the present invention to provide an ink ribbon switching mechanism that can switch the number of steps, and that has a simple structure and can reduce the number of manufacturing steps and the number of assembly steps.

[Means for solving problems]

To achieve this object, the present invention supports a ribbon cassette accommodating multicolor ink ribbons of two or more colors on a printer frame in a swingable and detachable manner, and a ribbon that moves up and down with the swing of the ribbon cassette. In an ink ribbon switching mechanism including a mask and a drive unit for swinging the ribbon cassette, a long hole is formed in the printer frame, and both ends of a rod for guiding the ribbon mask are inserted into the long hole. The rod is elastically urged against the lower surface of the ribbon cassette.

[Action]

Since the ink ribbon switching structure of the present invention is constructed as described above, the ribbon cassette is swung by the driving unit, and the rod elastically urged by the ribbon cassette is also moved up and down, so that the ribbon mask is moved. Is also moved up and down. And
In addition to changing the mounting angle of the ribbon cassette to the print head, the ribbon mask can also be moved up and down to switch the ink ribbon.

Further, when attaching and detaching the ribbon cassette, it is not necessary to fit it into the rod, and the conventional plate is not required, so that the structure is simple and the manufacturing man-hours and the assembly man-hours can be reduced.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1 showing a perspective view of an embodiment of the present invention,
Support shafts 3 are provided on both side surfaces of a ribbon cassette 2 accommodating the two colored ink ribbons 1. The support shaft 3 has a substantially U-shaped bearing 5 provided on a printer frame 4. It is fitted in and is rotatable, and as a result,
The ribbon cassette 2 can swing about a support shaft 3. Also, the ribbon cassette 2 has projections 6 on its side surface.
Is provided, and the driving force from the drive unit 7 is transmitted to the projection 6 to swing the ribbon cassette 2. The drive unit 7 is composed of a motor 8 attached to the printer frame 4, a small gear 9 fixed to the shaft of the motor 8, a gear 10 with a cam meshed with the small gear 9, and the like. A cam portion (not shown) 10 is detachably engaged with the protrusion 6.

Further, 11 is a ribbon mask, and this ribbon mask 11 is provided with a notch 13 corresponding to the portion of the print head 12 through which the wire passes, so that the ink ribbon 1 does not unnecessarily contact the recording paper and become dirty. I'm running. The ribbon mask 11 is provided with guide protrusions 14, 14 to guide the ink ribbon 1 so that the ink head 1 passes through the print head 12 at an appropriate position. The ribbon mask 11 is slidably supported by a rod 15, and both ends of the rod 15 are brought into contact with the lower surface of the ribbon cassette 2 and are inserted into the long holes 16 of the printer frame 4 to form an E ring 20. Etc. are prevented from coming off.
A projecting piece 16a is formed on the lower end edge of the elongated hole 16 so that the coil spring 1
7 holds one end of coil spring 17 and the other end of coil spring 17
Pressed on 5.

As shown in FIG. 2, a guide shaft 19 provided on a carriage 18 on which the print head 12 is placed is vertically inserted into the ribbon mask 11. The ribbon mask 11 can slide in the axial direction of the guide shaft 19.

Next, the operation of the ink ribbon switching mechanism configured as described above will be described.

As shown in FIG. 3, the ribbon cassette 2 (position indicated by the solid line)
Is the printing head at the bottom of the ink ribbon 1 colored in two colors
It is located to accommodate 12 wires. This time,
The rod 15 is in contact with the upper edge of the slot 16.

From this state, when the motor 8 is driven by the color change signal, the driving force is transmitted to the protrusion 6 via the cam portions of the small gear 9 and the gear 10, and the ribbon cassette 2 is moved downward around the support shaft 3. Push down. As the ribbon cassette 2 moves downward, the rod 15 contacted with the lower surface of the ribbon cassette 2 is a coil spring.
It is moved downward against the spring force of 17 and stops at the position where the coil spring 17 is contracted. This position (ribbon cassette 2 shown by the broken line,
At the rod 15), the upper stage of the ink ribbon 1 corresponds to the wire of the print head 12 and is printed in a different color. Further, the ribbon mask 11 is also moved down in correspondence with the downward movement of the ribbon cassette 2 so that the upper stage of the ink ribbon 1 is properly made to correspond to the wire.

When the color is changed again, when the motor 8 is rotated in the reverse direction to move the ribbon cassette 2 upward, the rod 15 pressed against the lower surface of the ribbon cassette 2 is moved upward together with the ribbon cassette 2 by the elastic force of the coil spring 17. .

On the other hand, the carriage 18 prints by moving the print head 12, and at this time, the guide mask 19 of the carriage 18 also moves the ribbon mask 11 along the rod 15 to mask it. On the other hand, the ribbon mask 11 is brought into and out of contact with the carriage 18 by the vertical movement of the rod 15, but the ribbon mask 11 is always caught on the guide shaft 19 of the carriage 18 and therefore is moved together with the carriage 18.

Next, the attachment / detachment of the ribbon cassette 2 will be described. First,
When mounting the ribbon cassette 2, the ribbon cassette 2 is mounted from above the printer frame 4 so that the support shaft 3 is fitted into the bearing 5 and the lower surface of the ribbon cassette 2 is brought into contact with the rod 15. Then, the protrusion 6 is a gear 10 with a cam.
And the ribbon cassette 2 is swung by the drive unit 7.

On the contrary, when detaching the ribbon cassette 2, if the ribbon cassette 2 is pulled upward and the support shaft 3 is removed from the tension bearing 5,
Only the ribbon cassette 2 can be removed while the rod 15 remains engaged with the slot 16.

In the above-described embodiment, the ribbon cassette 2 can be switched by changing the mounting angle of the ribbon cassette 2 with respect to the printing head 12, and the ribbon mask 11 can also be moved up and down, and the ribbon cassette 2 can be attached and detached. In this case, it is not necessary to fit it into the rod 15, and a conventional plate is not required, the structure is simple, and the number of manufacturing steps and the number of assembly steps can be reduced.

In the above embodiment, the ink ribbon 1 has two colors. However, the present invention is not limited to this, and the ink ribbon 1 may have three or more colors. In this case, the motor is controlled corresponding to each stage to perform positioning. Appropriate means such as the above may be applied. Also, rod 15
The means for elastically biasing is not limited to the coil spring 17, and biasing means such as a leaf spring may be used, and the installation location of such biasing means is not limited to the elongated hole 16 portion.

[Effect of device]

Since the present invention is configured as described above, the mounting angle of the ribbon cassette with respect to the printing head can be changed, the ribbon mask can also be moved up and down to switch the ink ribbon, and the rod is attached to the bottom surface of the ribbon cassette. Since it is elastically urged, it is not necessary to fit the ribbon cassette into the rod, and the conventional plate is not required. Therefore, the structure is simple, and the manufacturing man-hours and the assembly man-hours can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the ink ribbon switching mechanism of the present invention, FIG. 2 is a sectional view of the ribbon mask and the vicinity of the carriage, and FIG. 3 is a side view showing the switching operation. 1 ... Ink ribbon, 2 ... Ribbon cassette, 3 ... Support shaft, 4 ... Printer frame, 5 ... Bearing, 6 ... Projection, 7 ... Drive part, 11 ... Ribbon mask, 15 ... Rod , 16 …… elongated hole, 17 …… coil spring.

Claims (1)

[Scope of utility model registration request] 1. A ribbon mask which accommodates a multicolor ink ribbon of two or more colors in a printer frame so as to be swingable and detachable, and a ribbon mask which moves up and down as the ribbon cassette swings, and the ribbon cassette. In the ink ribbon switching mechanism including a drive unit for swinging the head, a long hole is formed in the printer frame, and both ends of a rod for guiding the ribbon mask are inserted into the long hole. An ink ribbon switching mechanism, characterized in that an elastically biasing the lower surface of the ribbon cassette.