JPH0632983B2 - Ribbon shift mechanism - Google Patents

Description

The present invention relates to a ribbon color switching mechanism for a serial printer.

(Prior Art) As an example of a ribbon shift mechanism of a conventional serial printer, Japanese Patent Laid-Open No. 56-16189 and Japanese Patent Laid-Open No. 57-18989.
-87394 and the like, and the examples disclosed therein are a carriage frame that has a dedicated motor or a dedicated operating magnet as its ribbon shift drive source, and that moves the drive source together with the print head. To be installed on.

(Problems to be Solved by the Invention) However, in the above-described conventional configuration, the entire carriage frame becomes heavy, making it difficult to speed up space operation and increasing power consumption. In addition, it is necessary to process the connection wiring between the mounted drive source and the external signal system, which increases the man-hours and the cost of the dedicated drive source itself, which leads to serial printer colorization, cost reduction, and size reduction. It was a big obstacle.

An object of the present invention is to realize a multicolor printer without providing a dedicated actuator as a drive source of a ribbon shift mechanism, and to reduce the price of a serial color printer.
A simple ribbon shift mechanism for speeding up and downsizing is disclosed.

(Means for Solving the Problems) In the mechanism of this type, the present invention provides a fulcrum on the side wall of the ribbon cartridge to enable the ribbon cartridge to be vertically swung about the fulcrum in a stepwise manner. A cam and a ribbon-down cam are fixedly provided on the frame at positions before and after the spacing operation, and the ribbon cartridge is made to swing stepwise according to the spacing operation.

(Operation) According to the present invention, the ribbon color positioning is determined by the two elements of the print head and the ribbon cartridge, and the shift power is moved in parallel with the cams provided on both sides of the printer and the platen of the carriage. It is obtained by a spacing operation, and will be described in detail according to the following embodiments.

(Embodiment) FIG. 1 is a left side view for explaining a carriage portion structure of an embodiment of the present application, and FIG. 2 is a perspective view for explaining an outline of a ribbon shift mechanism. The structure and operation will be described in detail below with reference to the drawings.

In FIG. 1, 1 is a platen, 2 is a print head, which is a wire dot type print head. Reference numeral 3 denotes an ink ribbon cartridge which has a vertical direction, for example, 4
An ink ribbon 4 in which color inks are arranged is built in.

Reference numeral 5 denotes a carriage that carries the dot head 2, the ink ribbon cartridge 3, etc., is supported by a guide shaft 6 and a guide rail 7, and moves in parallel with the platen 1. One end surface of the guide rail 7 is a rack having a tooth shape, and the feed drive force of the ink ribbon 4 is obtained via the pinion 8 pivotally supported by the carriage unit 5. The pinion 8 rotates forward and backward when the carriage 5 moves in both left and right directions, but a ribbon drive shaft 9, which will be described later and is obtained from the pinion 8 by a one-way mechanism (not shown), always rotates in one direction.

FIG. 2 is a perspective view of the carriage portion having the configuration described in detail in FIG. 1 as viewed from the upper left side. Particularly, the mechanism configuration of the ribbon shift will be described. The shift cam 10, and similarly, the up shift cam 11 fixed to the left frame of the printer,
Corresponding to these left and right shift cams, a pivot portion 3d as a down cam follower integrally formed on the ribbon cassette case is formed above the right ribbon guide arm of the ribbon cassette 3, and a ribbon cassette case is integrally formed below the left ribbon guide arm. There is a pivot part 3u as an up cam follower. Clamp levers 12 and 12 ′ for fixing the ribbon cassette 3 to the carriage 5 hold both side surfaces of the ribbon cassette 3 and support portions 13 integrally formed with the cassette case in the depth direction with respect to the front end of the print head from both side surfaces. The clamp levers 12, 12 'are bent by press-fitting the ribbon cassette 3 from above along the inclined surface of the tip end of the ribbon cassette 3, so that the operator can easily insert the ribbon cassette 3 into the carriage unit from above. it can.

FIG. 3 is a perspective view of the print head 2 in which one convex portion 2a is formed on each outer side of the head end portion.

FIG. 4 shows an ink ribbon cartridge 3, which is integrally formed of ABS resin or the like and has left and right ink ribbon guide arms 1.
Reference numerals 4 and 14 are sized and configured to hold both side walls of the front end portion of the print head 2 at four positions, that is, 3B and 3 respectively.
Recesses of Y, 3M and 3C are formed. Each recess 3B,
3Y, 3M, and 3C are color ribbons of four colors that are applied in layers in four layers, for example, cyan (red) C, magenta (blue) M, yellow (yellow) Y, black (black) B,
It is located corresponding to each layer of. The convex portion 2a of the print head, the concave portions 3B, 3Y, 3M of the ribbon cartridge,
3C is a concave portion, for example, 3B at one location corresponding to one color selected from the four colors, upper and lower, and the convex portion 2a of the print head.
The relative positional relationship between the print head and the selected color B of the ink ribbon is ensured, and the ink ribbon cartridge 3 is fixedly held on the carriage portion 5 at each point of the fulcrum portions 13 and 13 'and the fitting portions 3B and 2a. It has the function of

FIG. 5 is an explanatory view showing a power transmission member of the ribbon drive shaft 9.

As described in detail above, the ink ribbon cartridge 3 swings up and down in four steps around the fulcrums 13 and 13 'at the tip of the print head corresponding to each color. Along with this, the ribbon drive shaft 9 also swings about the fulcrums 13, 13 '. for that reason,
Twisting occurs in the power transmission part with the pinion 8 pivotally supported by the carriage part 5. Ribbon drive shaft 9
The lower part of the connection part 9'with the pinion 8 is solved by forming an hourglass-shaped cross hole as shown in the figure.

Now, the operation of the above configuration will be described.

The carriage 5 set and held at an arbitrary color position of the ink ribbon cartridge 3 moves to the down cam 10 side by a space drive source such as a wire (not shown). In response to this, the pivot portion 3d follows the down cam 10 and the ink ribbon cartridge moves downward.

That is, as shown in FIG. 6, the ribbon cartridge 3 and the print head 2 which have been fitted in the respective concave and convex portions are not fitted due to the bending of the guide arms 14 and 14 'of the ribbon cartridge 3, and the down cam Follow step 10
The combination is sequentially moved to 3M → 3Y → 3B. That is, the ink ribbon color corresponding to the dot pin of the print head 2 moves from cyan C → magenta M → yellow Y → black to be fixed.

Contrary to the above, when the space operation is performed toward the up cam 11 side, the ribbon color moves from black B → yellow Y → magenta M → cyan C.

As shown in FIG. 7, by appropriately selecting the movement amount in the arrow direction, that is, the space direction, selection of each color is easy, and the final positional relationship is assured by fitting the concave and convex portions as described above. Therefore, the positioning in the space direction may be rough, and the shift mechanism can be configured with a simple mechanism.

In addition, in the above embodiment, the concave and convex fitting portion is described,
It is needless to say that the purpose of the unevenness is to hold the selected position, so that it may have a shape sufficient to achieve the purpose, for example, zigzag fitting in a sawtooth shape.

Further, although the four-color ribbon is described in the above embodiment, it is needless to say that this is not limited to four colors, but can be widely applied to a serial printer that selects ribbons of a plurality of colors.

Further, the control method of the constituent mechanism of the present application is not limited to fixing the up cam and the down cam to the left and right side frames respectively as described in the above embodiment, but the cam is formed at a fixed position, that is, the ribbon shift position. It can be easily realized.

(Effects of the Invention) As described above, the fulcrum is formed on the inner side wall of the multicolor ribbon cartridge mounted on the carriage, and the print head tip portion holds the print head tip portion side wall so as to be swingable. Since the cartridge positioning mechanism is provided on the ribbon cartridge itself, which is a consumable item, since it is replaced at the same time as the consumption of the ribbon, the problem of wear of the fulcrum portion, the positioning fitting portion, the cam follower portion, etc. is regularly updated,
Solve. Further, as described above, since the color printer can be configured only by providing a drive unit such as a motor and a plunger in the carriage unit and a cam in a fixed unit that does not move without additional configuration of a mechanical member, This greatly contributes to downsizing, low power consumption, and low price.

[Brief description of drawings]

FIG. 1 is a left side view showing the structure of an embodiment of the present invention, FIG. 2 is the same perspective view, FIG. 3 is a perspective view of a print head, FIG. 4 is a perspective view of an ink ribbon cartridge, and FIG. 6 is an explanatory view showing a power transmission system of a ribbon drive shaft, FIG. 6 is an explanatory view showing a ribbon positioning means, and FIG. 7 is an explanatory view showing a ribbon-up cam. 2 ... Print head, 3 ... Ink ribbon cartridge,
4 ... Ink ribbon, 5 ... Carriage, 10 ... Down shift cam, 11 ... Up shift cam.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 60-229783 (JP, A) JP 59-67077 (JP, A) JP 56-64892 (JP, A)

Claims (1)

[Claims] 1. A ribbon shift mechanism of a printer, comprising: a print head mounted on a carriage; an ink ribbon having a multicolor in a vertical direction; and an ink ribbon cartridge containing the ink ribbon. A fulcrum is provided, and a ribbon positioning means is provided at the ribbon guide arm of the ribbon cartridge and the tip of the print head. The ribbon cartridge can be vertically swung about the fulcrum, and a ribbon up cam and a ribbon down cam are provided. A ribbon shift mechanism comprising a cam and a cam fixed to the frame at positions before and after the spacing operation, and the ribbon cartridge being stepwise rocked in accordance with the spacing operation to switch the ribbon.