JPH0156677B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a printing device that prints by appropriately switching a printing ribbon having at least two types of ribbon bands in the width direction.

Prior Art In accordance with a patent application filed at the same time, the present applicant has been able to switch between various ribbon bands in which the maximum upward movement width of the printing ribbon in the width direction is set short, and also to reduce the unprintable area at the top of printing paper. However, when replacing the print ribbon, the ribbon guide must be rotatably attached to the tip of the print head to match the reference position of the drive device, and the ribbon guide must be accurately positioned. It is difficult to attach the band to the ribbon band, and it has the disadvantage that switching to the ribbon band cannot be performed reliably.

Furthermore, as described in Japanese Unexamined Patent Publication No. 57-87394, a ribbon cassette is removably mounted on a pivot plate that is swingably provided on a carriage, and a grooved cam is rotated by a step motor to pivot the ribbon cassette. In devices that swing a pivot plate, it is known that in order to determine the reference position of the pivot plate, a command is given to the step motor to lower the pivot plate by the maximum amount, and the position where the pivot plate stops is set as the reference position. It is being However, in this case, each of the above parts must be accurately machined, assembled and adjusted so that the lower limit position of the grooved cam corresponds to the upper end zone of the printing ribbon via the pivot plate and the ribbon cassette. .

OBJECTS OF THE INVENTION In view of the above-mentioned conventional drawbacks, an object of the present invention is to easily position the ribbon guide to the reference position using simple means without requiring complicated assembly and adjustment, and to reliably switch ribbon bands. The purpose is to provide a printing device.

Structure of the Invention The present invention will be explained below according to one embodiment. FIG. 1 is an explanatory diagram showing an outline of the printing device according to the present invention, FIG. 2 is an explanatory diagram showing the ribbon zone in the printing ribbon, FIG. 3 is a front view of the ribbon guide attached to the printing head, and FIG. 4 3 is a plan view of FIG. 3, FIG. 5 is a right side view of FIG. 3, and FIG. 6 is a schematic sectional view taken along line AA in FIG. 3.

In the figure, a carriage 1 rotates a guide rod 3 fixed to a main body frame (not shown) in parallel with the axis of the platen 2, and a printing paper 4 mounted on the platen 2 is rotated by a step motor (not shown). It is inserted so that it can move back and forth along the print line.

The print head 5 is mounted and fixed on the carriage 1, and as the carriage 1 moves, a number of electromagnetic solenoids (not shown) are used to control the front frame 5a.
A printing wire (not shown) supported within the printer is selectively driven to print characters, etc. in a dot matrix format on the printing paper 4 via a printing ribbon 13, which will be described later. Further, a pair of shaft portions 5b that rotatably support a ribbon guide 6, which will be described later, in the width direction of the printing ribbon 13 are integrally formed on both sides of the front end portion of the front frame 5a.

The ribbon guide 6 has ribbon guide parts 7a and 8a that position the printing ribbon 13 substantially on the same plane as the printing end surface 5c at the tip of the front frame 5a, and also has a mounting hole 7 into which the shaft part 5b is inserted.
A pair of left and right guide bodies 7, 8 in which holes b, 8b are bored are connected to the upper parts of the guide bodies 7, 8,
When the ribbon guide 6 is rotated downward around the shaft portion 5b, a bridge portion 9 acts as a stopper that restricts the maximum rotational position of the ribbon guide 6 in the downward direction by contacting the upper surface of the front frame 5a. , extends rearward from the front end side of the guide bodies 7, 8 in a slightly inclined state, and has guide paths 10a, 11a for the printing ribbon 13 on its inner wall surface, and also has guide paths 10a, 11a for the printing ribbon 13 within the guide paths 10a, 11a. Guide members 10 and 11 are formed with slits 10b and 11b that are inserted and are opposed to the print end surface 5c of the print head 5, which is located substantially on the same plane as the ribbon guide parts 7a and 8a, and one guide body 7 side. A gear 12 having external teeth 12a having an appropriate number of teeth is integrally molded with resin on the outer periphery at a position concentric with the center of the mounting hole 7a.

The printing ribbon 13 has first to fourth ribbon bands 13a to 13d of different colors from its upper end in the width direction, and is endless and folded and stored in a ribbon cassette 14 that is detachably attached to the main body case. , are stretched around guide shafts 15 fixed to the main body case at both ends of the platen 2, and are inserted through the ribbon guide 6 to form a print end surface 5.
It is located opposite to c. Inside the ribbon cassette 14 is a ribbon drive motor 1 fixed to the main body case.
A ribbon feeding roller 18 is installed which is rotationally driven by a driven roller 17 and which folds and stores the printing ribbon 13 while pinching it with a driven roller 17.

The ribbon band switching drive device 19 includes a step motor 20 mounted and fixed on the carriage 1;
meshed with a drive gear 21 fixed to the rotating shaft of the step motor 20 and the gear 12;
and an idle gear 22 having an appropriate reduction ratio for sequentially switching the first to fourth ribbon regions 13a to 13d every predetermined number of steps of the step motor 20.

Next, the operation of this embodiment will be explained with reference to FIGS. 7 and 8.

First, in order to attach the printing ribbon 13 to the ribbon guide 6, first insert the slit 1 as shown by the dashed line in FIG.
Guide the printing ribbon 13 from 0b and 11b to the guide path 10.
a, 11a and positioned on the ribbon guide portions 7a, 8a which are substantially flush with the printing end surface 5c.

Then, after mounting the ribbon cassette 14 on the main body case and tensioning the printing ribbon 13 on the guide shaft 15, the shaft portion 5b is attached to the mounting holes 7b and 8b.
By inserting and fitting, the ribbon guide 6 is swingably attached to the tip of the printing head 5, and the printing ribbon 13 is made to face the printing end surface 5c. Also, by attaching the ribbon guide 6 to the print head 5, the gear 12
is meshed with the idle gear 22 at an arbitrary position.

By the above means, the ribbon guide 6 is moved to the print head 5.
When the power switch is turned on after the step motor 20 is attached to the tip of the ribbon, the control device (none of which is shown) moves the step motor 20 from the first ribbon zone 13a to the fourth ribbon zone 13d by open loop control. Rotation drive is performed for the required number of steps necessary to achieve this. As a result, the ribbon guide 6 is swung about the shaft portion 5b in the direction of the solid arrow shown in FIG. will be stopped.
At this time, the first ribbon zone 13a is positioned opposite to the printing end surface 5c. In addition, step motor 2
0 indicates the required number of steps in the ribbon guide 6.
The step is out of step by the difference between the number of steps corresponding to the fluctuation of the step. Therefore, the contact position between the front frame 5a and the bridge portion 9 is set as the reference position of the ribbon guide 6. As a result, the ribbon guide 6 is swung to the reference position as the step motor 20 is driven.
The first to fourth ribbon bands 13a to 13d can be selectively positioned with respect to the printing end surface 5c.

When the print data is input, the controller controls the step motor 20 based on the ribbon band data.
is rotated by a predetermined number of steps corresponding to the ribbon band data from the reference position, and the ribbon guide 6 is swung upward as shown by the solid line arrow in FIG. 8 about the shaft portion 5b to correspond to the ribbon band data. For example, after positioning the ribbon band 13c to face the printing end surface 5c, while moving the carriage 1 forward along the printing line of the printing paper 4, a dot pattern accessed from a pattern memory (not shown) based on the printing data is printed. Data is output to print head 5 to selectively drive print wires to
Characters, etc. are printed in the color corresponding to 3c. Then, similarly to the above operation, the control device rotates the step motor 20 by the number of steps calculated from its current position and the ribbon band data based on the next ribbon band data, and rotates the ribbon guide 6 around the shaft portion 5b. is rotated in the downward direction indicated by the broken line arrow in FIG. The previously printed characters, etc. are overprinted in the color corresponding to the switched ribbon band 13b, and the characters, etc. are printed in a desired color consisting of a mixed color of the colors corresponding to the ribbon bands 13b, 13c. .

After the above operation, the printing paper 4 is fed by one printing line by the rotational drive of the platen 2, and then the ribbon bands 13a to 13d are sequentially switched according to the above operation, and the colors corresponding to the switched ribbon bands 13a to 13d are Characters, etc. are printed in a desired color consisting of a mixture of colors.

In this way, in this embodiment, when the power switch is turned on, the step motor 20 is driven by the number of steps necessary to move the ribbon from the first ribbon zone 13a to the fourth ribbon zone 13d. After the swinging of the ribbon guide 6 is stopped by the contact between the connecting portion 9 and the upper surface of the front frame 5a, the step motor 20 is operated to match the required number of steps and the number of steps corresponding to the swinging of the ribbon guide 6. By stepping out by the difference, the contact position between the bridge portion 9 and the upper surface of the front frame 5a is set as the reference position of the ribbon guide 6, and the ribbon guide 6 is adjusted based on the reference position.
is swayed. Thereby, it is possible to reliably perform the switching operation of the first to fourth ribbon bands 13a to 13d with respect to the printing end surface 5c, and to print with high quality.

In this embodiment, a printing ribbon having four types of ribbon bands of different colors in the width direction or a printing ribbon having at least two ribbon bands of the same color in the width direction may be used. good. Furthermore, in this embodiment, the position where one ribbon band of the printing ribbon faces the printing surface was set as the reference position of the ribbon guide.
It goes without saying that the reference position of the ribbon guide may be the original position where the printing ribbon does not face the printing surface and where the printed characters, etc. can be visually seen, as shown in No. 3, etc.

Effects of the Invention As described above, the present invention rotates the ribbon guide inserted through the print ribbon portion facing the print head using a step motor until it hits the stopper on the carriage, and switches the ribbon band based on the stop position. . Therefore, since there are no extra parts between the ribbon guide and the printing ribbon, the relative position between the ribbon guide's stop position and the printing ribbon can be determined accurately, and advanced technology is not required for assembly and adjustment. This has the advantage of not being necessary.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the outline of the printing device according to the present invention, FIG. 2 is an explanatory diagram showing the ribbon zone in the printing ribbon, FIG. 3 is a front view of the ribbon guide attached to the printing head, and FIG. 4 is the plan view of Figure 3,
Figure 5 is the right side view of Figure 3, Figure 6 is Figure 3A-
The schematic sectional view taken along line A, FIGS. 7 and 8 are explanatory diagrams showing the operating states, respectively. In the figure, 6 is a ribbon guide, 9 is a bridge part as a stopper, 13 is a printing ribbon, 13a to 13d are ribbon bands, 19 is a ribbon band switching drive device, 2
0 is a step motor.

Claims (1)

[Scope of Claims] 1. A platen that supports printing paper, a carriage on which a printing head is placed and can run parallel to the platen, a printing ribbon stretched along the platen, and a printing ribbon through which the printing ribbon is inserted. a ribbon guide rotatably supported on the carriage so as to be rotatable about an axis parallel to the platen so as to move the print ribbon in the portion facing the print head in the width direction; a step motor that rotates the ribbon guide, and a stopper provided on the carriage so as to stop the ribbon guide at one end of its rotation range, and the ribbon guide and the stopper are brought into contact by the step motor, thereby . A printing device characterized in that the step motor is brought out of step and the ribbon guide is positioned at a reference position.