JPH068604A - Shifting apparatus of ribbon cassette of printer - Google Patents

Abstract

PURPOSE:To provide a compact ribbon cassette shifting mechanism which makes a carriage of a printer lightweight thereby to reduce the size and weight of the printer. CONSTITUTION:A ribbon shift cam 16 is mounted to be movable in the axial direction of a guide shaft 4 and moved along with a carriage 6. The guide shaft 4 is set in side frames 2, 3 in the rotatable fashion, with a gear 20 fixed at one end thereof. Accordingly, since the ribbon shift cam 16 is mounted in the movable manner to the guide shaft 4, the carriage 6 can be made light in weight and the printer can be made compact and lightweight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon cassette shift device for a printer, and more particularly to a ribbon cassette shift device for a printer having a ribbon in which a large number of colors are provided in multiple stages in the width direction.

[0002]

2. Description of the Related Art In recent years, a printer is often equipped with a ribbon cassette shift device. When the ribbon cassette shift device shifts the ribbon cassette up and down, the ribbon and the print head are separated from each other. The relative positional relationship can be changed, and the color to be printed by the color ink ribbon can be selected.

Conventionally, a ribbon cassette shift device mounted on a printer has a ribbon cassette shift mechanism provided on a carriage, and thus there is a limit to reducing the weight of the carriage. However, there is a problem in that it cannot be replaced with an inexpensive one having a small torque, and further, the accuracy of the printing operation accompanying the movement of the carriage cannot be further improved.

Therefore, it is possible to reduce the carriage by mounting the ribbon cassette shift mechanism separately from the carriage.

A typical prior art relating to a ribbon cassette shift device of a printer in which a ribbon cassette shift mechanism is mounted separately from a carriage is disclosed in Japanese Patent Laid-Open No. 63-796.
7 (Published Patent Publication).

FIG. 4 is a top view showing an essential part of a printer using the ribbon cassette shifting device of this prior art printer, FIG. 5 is a sectional view taken along line BB of FIG. 4, and FIG.
(A), (b) is a figure which shows the operation state of the principal part of this printer.

First, the structure will be described with reference to FIG.
In FIG. 6, 1 is a print head for printing on a print sheet (not shown), 2 and 3 are side frames, 4 and 5 are guide shafts provided between the side frames 2 and 3, 6 is a guide shaft 4, 5 is a carriage that is reciprocated by being guided by the carriage 5. The carriage 6 has bearing portions 8 and 9 for supporting a ribbon cassette 7 that stores an ink ribbon (not shown), and the shaft portions 10 on both sides of the ribbon cassette 7 are provided. And 11 are rotatably supported.

Reference numeral 12 denotes a shift arm which is rotatably attached to the center of the carriage 6 with a pin 13 as a fulcrum.
One end 14 is in contact with the bottom surface of the ribbon cassette 7, and the other one end 22 is attached with a roller 23.
A leaf spring 24 is fixed to the carriage 6 and pushes up the bottom surface of the ribbon cassette 7 in the direction of the arrow (A) by a spring force. The print head 1 side of the ribbon cassette 7 uses the bearings 8 and 9 as fulcrums. , The force in the direction of the arrow (B) is constantly acting, and the force is in contact with the one end 14 of the shift arm 12.

Reference numeral 25 denotes a cam shaft, which is rotatably attached to the auxiliary frames 26 and 27. Ribbon shift cams 28 and 29, and gears 30 are fixed to the cam shaft 25. Reference numeral 31 denotes a shift plate extending between the auxiliary frames 26 and 27, which is a roller 2 of the shift arm 12.
3, the shaft 32 is slidably installed in the shaft 32 via a coil spring 33 in the direction of the arrow (C), and is always in contact with the ribbon shift cams 28 and 29 by the spring force of the coil spring 33. 28,
The position of the shift plate 31 is set by 29.

When the carriage 6 reciprocates for printing, the roller 23 moves along with the carriage 6 while rotating along the shift plate 31 positioned by the ribbon shift cams 28 and 29, so the position of the roller 23 is also set. , Retained.

Reference numeral 34 is a motor, 35 is a worm gear attached to the rotating shaft of the motor 34, and meshes with the gear 30. The rotation of the motor 34 is transmitted to the rotation of the camshaft 25.

Next, the operation of the above configuration will be described with reference to FIGS. 6 (a) and 6 (b).

First, when the motor 34 rotates, the cam shaft 25 rotates via the worm gear 35 and the gear 30, and the ribbon shift cams 28 and 29 fixed to the cam shaft 25 also rotate.

As shown in FIG. 6A, at a certain rotation angle,
When the long diameter portions of the ribbon shift cams 28 and 29 come into contact with the shift plate 31, the shift plate 31 is pushed down in the arrow (D) direction and slides. Therefore, the roller 23 in contact with the shift plate 31 is also pushed down in the same direction,
The shift arm 12 has a pin 13 as a fulcrum, and an arrow (E)
The ribbon cassette 7 shifts in the direction of arrow F by the one end 14 of the shift arm 12 pushing up the bottom surface of the ribbon cassette 7 and rotating about the bearings 8 and 9 as fulcrums.

Next, as shown in FIG. 6B, at a certain rotation angle, the short-diameter portions of the ribbon shift cams 28 and 29 are shifted to the shift plate 3.
When it comes to a position in contact with 1, the shift plate 31 is pushed up by the coil spring 33 and slides in the arrow (G) direction. That is, since the shift plate 31 slides away from the roller 23, there is no stopper-like factor for the rotation of the shift arm 12 in the arrow (G) direction, so that the leaf spring 24 always uses the bearings 8 and 9 as fulcrums to support the arrow ( Ribbon cassette 7 in which rotational force in direction B) is working
Will push down one end 14 of the shift arm 12 and rotate in the direction of the arrow (B).

As described above, the ribbon shift cams 28, 2
By controlling the rotation angle of 9 and changing the slide amount of the shift plate 31, the ribbon cassette 7 is shifted, and the relative positional relationship of the ink ribbon (not shown) to the print head 1 can be controlled. Becomes

[0017]

However, in the ribbon cassette shift device for a printer using such a conventional technique, the ribbon cassette shift mechanism is mounted separately from the carriage 6 to reduce the carriage 6. Although it can be achieved, since the ribbon cassette shift mechanism is attached to the auxiliary frames 26 and 27, the structure of the printer becomes large as compared with the case where the ribbon cassette shift mechanism is mounted on the carriage 6, and the size and weight of the printer are reduced. However, there is a problem in that it cannot be further improved.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce the number of carriages by mounting the ribbon cassette shift mechanism separately from the carriage, and at the same time, to improve the printer. Another object of the present invention is to provide a ribbon cassette shift device having a compact mechanism capable of further improving the size and weight reduction of the device.

[0019]

In order to solve the above-mentioned problems, the ribbon cassette shifting device of the printer of the present invention is
In a printer having a carriage movable along a guide shaft arranged in parallel with a printing surface, and a ribbon cassette mounted on the carriage and vertically rotatable around a bearing provided on the carriage. ,
A shift arm that is provided on the carriage and that vertically rotates the ribbon cassette that is in contact with the other end in response to a change in the amount of vertical movement received at one end, and a shift arm that contacts one end of the shift arm And a ribbon cassette shift mechanism for giving a vertical movement.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a top view of a printer using a ribbon cassette shifting device of the printer of the present invention, FIG. 2 is a partial cross-sectional top view of the main part of FIG. 1, and FIGS. It is a side view which shows an operating state.

First, the structure will be described with reference to FIG.
1 is a print head for printing on a print sheet (not shown), 2 and 3 are side frames of the printer, 4
Reference numerals 5 and 5 denote guide shafts provided between the side frames 2 and 3. Reference numeral 6 denotes a carriage which is guided by the guide shafts 4 and 5 to reciprocate. The carriage 6 has a ribbon cassette 7 for accommodating an ink ribbon (not shown). It has bearings 8 and 9 for supporting, and rotatably supports the shafts 10 and 11 on both sides of the ribbon cassette 7.

Reference numeral 12 denotes a shift arm which is rotatably attached to the center of the carriage 6 with a pin 13 as a fulcrum.
One end 14 is in contact with the bottom surface of the ribbon cassette 7, and the other end 15 is in contact with the ribbon shift cam 16. As shown in FIGS. 3A and 3B, a spring 17 is fixed to the carriage 6 and a bottom surface of a member 19 formed on the ribbon cassette 7 via a push-up member 18 is pressed by an arrow (a). ) Direction, the print head 1 side of the ribbon cassette 7 is always in contact with the one end 14 of the shift arm 12 with a force acting in the arrow (B) direction with the bearings 8 and 9 as fulcrums.

The ribbon shift cam 16 is attached so as to be movable in the axial direction of the guide shaft 4, as shown in FIG.
It moves along with the carriage 6 which is guided by the guide shafts 4 and 5 and reciprocates. Further, as shown in FIG. 1, the guide shaft 4 is rotatably attached to the side frames 2 and 3, and the gear 20 is fixed to one end thereof. A key groove 21 is formed in the guide shaft 4, and rotation of the gear 20 by a power source (not shown) is
It is transmitted to the rotation of the ribbon shift cam 16 through the key groove 21 of.

Next, the operation of the present embodiment configured as described above will be described with reference to FIGS. 3 (a) and 3 (b).

First, the gear 2 is driven by a power source (not shown).
When 0 rotates, the guide shaft 4 rotates, and the ribbon shift cam 16 also rotates via the key groove 21 of the guide shaft 4.

As shown in FIG. 3A, at a certain rotation angle,
When the short diameter portion of the ribbon shift cam 16 comes into contact with the one end 15 of the shift arm 12, the one end 15 is pushed up by the spring 17 in the arrow (C) direction. That is, the ribbon cassette 7 in which the rotational force in the arrow (B) direction is always acting by the springs 17 with the bearings 8 and 9 as the fulcrum,
One end 14 of the shift arm 12 is pushed down and the shift arm 12 is rotated in the arrow (B) direction. Next, as shown in FIG.
When the long diameter part of the ribbon shift cam 16 comes into contact with one end 15 of the shift arm 12 at a certain rotation angle, one end 15
Is pushed down in the direction of arrow (d). Therefore, the shift arm 12 rotates in the arrow (e) direction with the pin 13 as a fulcrum, one end 14 of the shift arm 12 pushes up the bottom surface of the ribbon cassette 7, and the bearings 8 and 9 as a fulcrum in the arrow (f) direction. The ribbon cassette 7 is rotated and the ribbon cassette 7 is shifted.

As described above, the ribbon cassette 7 is shifted by controlling the rotation angle of the ribbon shift cam 16 and changing the movement amount of the one end 15 of the shift arm 12, and the ribbon head 7 is not shown with respect to the print head 1. It is possible to control the relative positional relationship of the ink ribbons.

[0028]

As described above, in the present invention,
Even if the carriage and the ribbon cassette shift mechanism are arranged separately, they can be organically combined and operated by the shift arm, so that they can function as a printer while the carriage is not Since the ribbon cassette shift mechanism is not attached, the weight of the carriage can be easily reduced. Moreover,
Since the ribbon shift cam is movably attached to the guide shaft, the ribbon cassette shift mechanism is compact, and the size and weight of the printer can be further improved.

[Brief description of drawings]

FIG. 1 is a top view of a printer using a ribbon cassette shifting device of the present invention.

FIG. 2 is a partial top cross-sectional view of a main part of a printer using the ribbon cassette shifting device of the present invention.

FIG. 3 is a side view showing an operation state of a main part of a printer using the ribbon cassette shifting device of the present invention.

FIG. 4 is a top view of a printer using a ribbon cassette shifting device of the related art.

FIG. 5 is a side sectional view of a main part of a printer using a ribbon cassette shifting device of the related art.

FIG. 6 is a side view showing an operation state of a main part of a printer using a ribbon cassette shift device of a conventional technique.

[Explanation of symbols]

 1 Print head 2, 3 Side frame 4, 5 Guide shaft 6 Carriage 7 Ribbon cassette 8, 9 Bearing part 10, 11 Shaft part 12 Shift arm 14, 15, 22 One end 16, 28, 29 Ribbon shift cam 17 Spring 20, 30 Gear 21 Key Groove 23 Roller 24 Leaf Spring 25 Camshaft 26, 27 Auxiliary Frame 31 Shift Plate 32 Shaft 33 Coil Spring 34 Motor 35 Worm Gear

Claims (2)

[Claims] 1. A carriage movable along a guide shaft arranged parallel to a printing surface, and a carriage mounted on the carriage and rotatable in the up-down direction about a bearing provided on the carriage. In a printer having a ribbon cassette, a shift arm that is provided on the carriage and that vertically rotates the ribbon cassette that is in contact with the other end in response to a change in the amount of vertical movement received at one end, A ribbon cassette shift device for a printer, comprising: a ribbon cassette shift mechanism that contacts one end of the shift arm and vertically moves the shift arm. 2. The ribbon cassette shift mechanism, wherein a ribbon shift cam attached to the guide shaft and movable along the guide shaft is brought into contact with one end of the shift arm, and the ribbon shift cam is rotated to rotate the shift arm. 2. A ribbon cassette shifting device for a printer according to claim 1, wherein one end of said ribbon cassette shifting device is vertically moved.