JPH0588199B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a color ink ribbon switching device for a printer in which a color ink ribbon cassette is mounted on a carriage.

(Prior art) As a color ink ribbon switching mechanism, a motor,
When a dedicated drive source such as a solenoid is used, or when the carriage is located outside the printing area, the color ink ribbon cassette lift cam, which is integrated with the carriage and is integrated with the color ink ribbon cassette lift cam follower, is installed on one side of the carriage guide shaft. It is known from Japanese Patent Laid-Open No. 55-34991 to make contact and tilt the color ink ribbon switching device by controlling the movement of the carriage until the requested color ink ribbon is selected.

(Problems to be Solved by the Invention) In the above-mentioned prior art, the former method using a dedicated drive source is very expensive, and the latter method uses a slide control of the carriage to move the color ink ribbon cassette lift cam to a specific position. The color ink ribbon cassette cam follower is then stopped, and the color ink ribbon cassette is selectively positioned at a predetermined ribbon color position via the index mechanism. Because the color ink ribbon switching mechanism can only be placed on one side, if the carriage is on the other side, it must be returned to one side to switch the color ink ribbon, which reduces throughput in this type of printer. There was a problem.

(Means for Solving the Problems) The present invention has been made in view of the above-mentioned problems, in which a lift cam is disposed on the carriage so as to be able to rotate in one direction, and a switching lever for rotating the lift cam is connected to the carriage. The color ink ribbon cassette is slidably protruded in the sliding direction on both sides, is always biased in the protruding direction by a spring, and the color ink ribbon cassette and the lift cam are interlocked;
The present invention is characterized in that the carriage has a stopper for pressing and sliding the switching lever and rotating the lift cam at a position beyond the printing area.

Hereinafter, a detailed explanation will be given based on the illustrated embodiment. 1 is a guide bar 2 arranged parallel to the main body
This is a carriage that slides along lines a and 2b. 3
1 is a lift cam disposed at the center of the upper surface of the carriage 1 so as to be able to rotate in one direction. A cam 4 is integrally formed along the outer circumference in a stepped manner, and four claws 5a, 5b, 5c, and 5d are provided at the lower end. It is divided into equal parts on the circumference and protrudes radially. Switching levers 6a, 6b are protruded from both sides of the carriage 1, and long grooves 6a', 6
b' slides along pins 7a, 7b on the carriage 1 in the sliding direction of the carriage 1, and the inner tips of the switching levers 6a, 6b are connected to the claws 5a, 5b,
5c and 5d are engaged and pressed. 8
Reference numerals a and 8b are springs that always urge the switching levers 6a and 6b toward the outer position. Reference numeral 9 denotes a ribbon holder, which carries a cassette 11 containing color ink ribbons 10 in which ink ribbons of four colors of yellow, cyan, magenta, and black are arranged side by side.
Insert pins 9a and 9b on both sides into holes 12a' and 12b' of 2b.
It is fitted so that it can swing up and down. Reference numeral 13 denotes a lift lever that is vertically movably fitted into a guide 14 that projects perpendicularly to the top surface of the carriage 1. The guide 13a holds the step-shaped cam 4, and the ribbon holder 9 is inserted into the groove 13b.
The pin 9b on the lower surface is fitted. Stoppers 15a and 15b are provided for pressing and sliding the switching levers 6a and 6b when the carriage 1 reaches a position beyond the printing area. 16 is a carriage and color ribbon home position detection sensor mounted on the printer body base; 17 is a color ribbon home position detection sensor 16 mounted on the lift lever 13;
This is a shielding plate.

Next, the effect will be explained. When the carriage 1 moves beyond the normal printing area to the right in the state shown in FIG. 5, the right switching lever 6b is moved as shown in FIG.
contacts the stopper 15b. The lift cam 3 is held in position by the load of an index spring (not shown). When the carriage 1 further moves to the right as shown in FIG. 7, the switching lever 6b moves to the left against the spring force of the spring 8b. At that time, it is slid and guided by the pin 7b on the carriage 1, the long hole 6b' of the switching lever 6b, the pin 6b'' of the switching lever 6b, and the cam 20b of the carriage 1, and pushes the pawl 5a of the lift cam 3 to move the lift cam 3 by 1/4. The index spring holds the lift cam 3 stronger than the springs 8a and 8b.

Next, when the carriage 1 moves to the left and the switching lever 6b moves away from the stopper 15b as shown in FIG. 8, the switching lever 6b returns to its original state by the action of the spring 8b. At this time, the tip of the switching lever 6b passes over the claw 5b, and the pin 6b'' moves downward along the cam 20b, and is regulated by the pin 7b and the elongated hole 6b' and returns to the original position shown in FIG. 5. Action 2
When the lift cam 3 is rotated, it rotates 1/2, when it rotates three times, it rotates 3/4, and when it rotates four times, it rotates once. Every time lift cam 3 rotates 1/4, cam 4 moves lift lever 1.
The ribbon holder 9 moves the lift lever 13 up and down to shift the cassette 11 housed in the ribbon holder 9 into four stages.

In this embodiment, depending on the stepwise cam deviation position of the lift cam 3, a...black, b...cyan, c...
magenta, d...yellow. Other combinations are also possible. The number of rotations of the lift cam 3 is controlled according to the selected color of the required color ink ribbon 10 by sending a signal so that a predetermined color ink ribbon can be selected. When the carriage 1 moves to the left, the switching lever 6b is returned to its original position by the spring 8b.

(Effects) According to the present invention, the lift cam is disposed on the carriage so as to be able to rotate in one direction, and the switching lever for rotating the lift cam is slidably protruded in both sliding directions of the carriage, and is always protruded by a spring. bias in the direction,
The color ink ribbon cassette and the lift cam are interlocked, and the carriage presses and slides the switching lever at a position beyond the printing area, and has a stopper for rotating the lift cam.
Color ink ribbons can be shifted accurately using a simple mechanical method that does not require a dedicated drive source such as a motor or solenoid, but simply controls the movement of the carriage by touching the switching lever to the stoppers on the left and right sides of the main body. Furthermore, since the ribbon can be shifted at either the left or right end, the throughput of this type of printer can be greatly improved.

Note that the ribbon holder and lift lever are not essential requirements for the configuration of the present invention; the combination of the color ribbon cassette lift cam and the switching lever drives the lift cam, and the color ribbon cassette is directly moved by following the amount of cam deviation caused by the drive. It can also be moved up and down. The lift cam shown in the embodiment is a preferred embodiment in which the cam follower is vertically moved through a three-dimensional cam that is equally divided on the circumference and protruded from the screw lock. You may also use a cam that positions the Further, the ribbon cassette lift mechanism does not necessarily have to swing the ribbon cassette by the movement of the lift cam. Following the movement of the lift cam, for example, a rail and cassette guide pin formed integrally with the carriage, via a parallel link, are used as a color ribbon cassette and a lift guide, and the cassette is moved parallel to the carriage base (print head tip wire arrangement) following the movement of the lift cam. The ink ribbon may be lifted in the vertical direction while maintaining a constant distance between the surface and the ink ribbon.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an embodiment of the present invention, Fig. 2 is a left side view of Fig. 1, Fig. 3 is a front view of main parts of Fig. 1,
FIG. 4 is a perspective view of FIG. 3, FIGS. 5 to 8 are plan views explaining the operation of the lift cam, and FIG. 9 is an explanatory diagram showing shifting of the lift lever guide in four stages. 1...Carriage, 3...Lift cam, 4...
Cam, 5a, 5b, 5c, 5d...Claw, 6a, 6
b...Switching lever, 8a, 8b...Spring, 9...
Ribbon holder, 10...color ink ribbon,
11...cassette, 13...lift lever, 13
a...Guide, 13b...Groove, 15a, 15b...
…stopper.

Claims (1)

[Claims] 1. A lift cam is disposed on the carriage so as to be able to rotate in one direction, a switching lever for rotating the lift cam is slidably protruded in the sliding direction on both sides of the carriage, and is always biased in the protruding direction by a spring; interlocking the color ink ribbon cassette and the lift cam,
A color ink ribbon switching device for a printer, comprising a stopper for pressing and sliding the switching lever at a position where the carriage exceeds the printing area and rotating the lift cam.