JPH06171115A - Wire dot printer capable of switching print mode - Google Patents

Abstract

PURPOSE:To switch relative positions of print wires in two rows by a simple structure and change longitudinal pitches between the print wires without necessitating high dimensional precision. CONSTITUTION:An iron core 2, a drive coil 3, a print lever 4, and a return spring 5 are provided in a print head 1 for an electromagnetic drive device, and twenty-four print wires 6 are fixed to the inner end part of the print lever 4. The print wires 6 penetrate a nose 7a protruding forward from a head frame 7 and are aligned in two rows in the longitudinal direction by first and second tip guides 8 and 9. The first tip guide 8 is fixed by fixing axes 10 and 11, and the second tip guide 9 is arranged in a rocking way with rocking center at the fixing axis 10 in the direction of its face. Long grooves in two rows are provided at the guide 8 in the longitudinal direction and each print wire 6 penetrates the guide 9 in which a plurality of slidable grooves are provided. The grooves are arranged in the lateral direction with multiple steps having different angles respectively, so that relative positions of the print wires 6 or longitudinal pitches between the print wires 6 can be changed by the rocking of the guide 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire dot printer capable of switching print modes.

[0002]

2. Description of the Related Art Conventionally, there is a print head in which a plurality of print wires are electromagnetically driven to form a dot matrix print on a print medium on a platen via an ink ribbon at the tip of the print wires. In recent years, high density printing has been required, and the number of printing wires has increased accordingly. For example, 24 printing wires are arranged in two rows in a direction substantially orthogonal to the moving direction of the print head. . The tip portion of each print wire penetrates a predetermined guide hole of the tip guide.

As the arrangement of the print wires, there are a parallel arrangement in which two wires adjacent to each other in the moving direction of the print head are located at the same level, and a staggered arrangement in which the positions are displaced by half a pitch from each other. High-speed printing (Dra
Suitable for ft mode) and zigzag arrangement for high density printing (NLQ
(Near Letter Quality) mode)
Suitable for

The prior art discloses a configuration in which the parallel arrangement and the staggered arrangement can be arbitrarily switched as needed, and the vertical pitch of the parallel arrangement can be changed as necessary.

First, in Japanese Patent Publication No. 57-60950, a wire guide is divided into two parts, and guide holes for guiding half of the printing wires are arranged in one line in the vertical direction. It is disclosed that the relative positions of the print wires are switched to the parallel arrangement or the zigzag arrangement by moving both wire guides in the vertical direction relatively.

Secondly, Japanese Patent Laid-Open No. 25345/1989
In Japanese Patent No. 5 publication, two wire guides for guiding a print wire are laminated, one wire guide is provided with two parallel vertical grooves, and half of the print wires are fitted in each vertical groove. In the other wire guide, inclined grooves having different inclination angles with respect to the horizontal line are provided corresponding to the respective print wires, and the print wires are arranged in a staggered manner by both guides. The inclined groove has one end with a small pitch and the other end with a large pitch. By moving both wire guides relatively horizontally, the vertical pitch of the printing wire is changed. The configuration is shown.

[0007]

In the first prior art described above, since the wire guide is divided into two, it is necessary to obtain the relative positional accuracy between the print wires guided by each wire guide. Since it is difficult and one of them is moved in the vertical direction, the dimensional accuracy of the supporting portion for that is required, and a driving device is required, which increases the cost.

Since the above-mentioned second conventional technique is moved in the horizontal direction, the dimensional accuracy of the supporting portion for supporting this wire guide is required, and the cost of parts is increased.

Therefore, an object of the present invention is to enable switching of the relative positions of the two rows of print wires and change of the vertical pitch between the print wires with a simple structure without requiring a high degree of dimensional accuracy. It is in.

[0010]

In order to achieve the above object, a wire dot printer of the present invention is mounted on a carriage, moved in the width direction of a recording medium, and electromagnetically driven. In a wire dot printer having a print head in which a print wire is aligned and supported by a nose portion of a head frame, first and second tip guides that align the tip portions of the print wires in at least two rows are printed on the nose portion. They are provided so as to face each other in the drawing direction of the wire. The first tip guide is provided with at least two long grooves extending in the longitudinal direction in parallel, and a plurality of printing wires pass through each long groove. In the second tip guide, a plurality of grooves through which each print wire penetrates and which can be slid are provided so that the relative position of at least two rows of print wires or the vertical pitch between each print wire can be changed by swinging. It is provided. One of the first and second tip guides is fixed, and the other is supported so as to be swingable in the surface direction with one end thereof as the swing center.

One end of the groove of the second tip guide is provided at a position for guiding the print wires in a staggered arrangement and at a large vertical pitch, and the other end is provided in a groove in a staggered arrangement and at a small vertical pitch. Is provided at a position for guiding the print wire, and between the one end and the other end, the print wire is provided at a position for guiding the print wire to a gradually smaller vertical pitch, and the vertical pitch of the print wire is changed by swinging.

Further, the groove of the second tip guide is provided at one end thereof at a position for guiding the print wires in a zigzag arrangement and at a large vertical pitch, and from the one end to the central portion thereof. , The print wires are arranged in a zigzag arrangement and at a position that guides the print wires in a gradually smaller vertical pitch, and the other end is provided in a position that guides the print wires in a parallel layout and at a smaller vertical pitch. Along with changing the vertical pitch of, the staggered arrangement and the parallel arrangement are switched.

As means for swinging one of the tip guides, a driven tooth profile is provided at the other end of the second tip guide, and has a drive tooth profile that meshes with the driven tooth profile and is swingably supported. A switching lever may be provided, and the second tip guide may be rockably driven by rocking the switching lever.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the preferred embodiments with reference to the drawings.

FIG. 1 shows a front view of a print head 1 for forming wire dots, and FIG. 2 shows a cross section thereof. As shown in FIG. 2, the print head 1 includes an iron core 2, a drive coil 3, a print lever 4, a return spring 5 and the like as an electromagnetic drive device. Twenty-four print wires 6 are fixed to the inner ends of the print levers 4, and are printed when the inner ends of the print levers 4 are sucked by the iron core 2 and advanced, and are retracted by the spring force of the return spring 5. . A head frame 7 is fixed to the front surface of the print head 1, and the print wire 6 is attached to the head frame 7.
It penetrates through the inside of the nose portion 7a that projects forward from and is aligned by the first and second tip guides 8 and 9.

The first tip guide 8 is fixed to the front end of the nose portion 7a of the head frame 7 to serve as a fixed guide. That is, as shown in FIG. 3, fixing holes 8a and 8b are provided at both upper and lower ends, and fixed to the nose portion 7a using the fixing shafts 10 and 11 shown in FIG. Further, the first tip guide 8 is provided with two parallel rows of long grooves 8c and 8d extending in a direction (vertical direction) orthogonal to the moving direction of the print head 1 in parallel. Each of the long grooves 8c and 8d has a length such that twelve printing wires 6 penetrate therethrough and have a sufficient clearance.

The second tip guide 9 is located at the rear portion near the first tip guide 8 and has a hole 9a at the lower end as shown in FIG.
The fixed shaft 10 is rotatably passed through the hole 9a. Therefore, the second tip guide 9 can swing in the surface direction around the fixed shaft 10 as the swing center.
An arcuate guide hole 9b centered on the fixed shaft 10 is provided at the upper end of the second tip guide 9. This guide hole 9
The fixed shaft 11 passes through b. Further, the second tip guide 9 is provided with a plurality of slidable grooves 9c and 9d through which the respective printing wires 6 pass, and the second tip guide 9 swings to be arranged in two rows. It is possible to change the relative positions of the print wires 6 and 6 or the vertical pitch between the print wires.

An example of a concrete shape of the grooves 9c and 9d will be described with reference to FIG. The grooves 9c and 9d are arranged in two rows with a length that extends from the lower groove to the upper groove in a substantially fan shape, and the grooves have different inclination angles with respect to the horizontal direction. That is, as shown in FIG. 5A, when the print wires 6 are located in two rows at one end (right end) of the groove in each row, the relative arrangement of the print wires is staggered and small. The print wire is guided at a vertical pitch. Further, as shown in FIG. 5B, when the print wires 6 are located in two rows at the other end (left end) of the groove in each row, the relative arrangement of the print wires is staggered, and The print wire is guided with a large vertical pitch. And
The print wire is guided so that the vertical pitch gradually changes from a small vertical pitch to a large vertical pitch from the one end to the other end. As shown in FIG. Guided at an intermediate vertical pitch.

The means for swinging the second tip guide 9 is
A protrusion (not shown) may be integrally provided, and the protrusion may be manually swung, but as shown in FIGS. 1, 2 and 6, it may be swung via the switching lever 12. That is, the driven tooth profile 9e is integrally provided on the other end of the tip guide 9, and the switching lever 12 is provided with a drive tooth profile 12a which meshes with the driven tooth profile 9e. The central shaft 13 of the driving tooth profile 12a is fixed to the head frame 7, and thereby the switching lever 12 is pivotally supported about the central shaft 13 so as to be swingable.

In order to position the switching position of the switching lever 12, the click claw 12b is projected on the rear surface of the switching lever and the click claw 12b is provided on the upper surface of the head frame 7.
Form a click 7b that can be selectively engaged. By engaging the both, the switching lever 12 can be switched in stages, and its position is maintained stably. Further, a stopper 14 is provided upright on the front surface of the head frame 7 so as to determine the switching lever 12. Reference numeral 15 is an ink ribbon insertion guide.

Next, the operation will be described. First, when printing at the highest density, as shown in FIG. 6, the switching lever 12 is swung clockwise around the central shaft 13 and the second tip guide 9 is fixed to the fixed shaft via the drive tooth profile 12a. 10
Swing counterclockwise around. This state is shown in Fig. 5 (a).
In this state, the print wire 6 is guided to the right end portions of the grooves 9c and 9d, and the long groove 8 of the first tip guide 8 is provided.
Aligned in two rows, also guided by c and 8d. That is,
The two rows of printing wires are staggered and the vertical pitch is small. When printing with this print wire arrangement,
Since the amount of overlap of dots formed by the adjacent print wires is large, the print density is the highest and the print quality is comparable to that of printed characters.

When it is desired to print a large character even if the printing density is slightly inferior, the switching lever 12 is swung counterclockwise around the central axis 13 to move the second tip guide 9 around the fixed axis 10. Swing clockwise. As a result,
As shown in (b), the printing wire 6 is guided to the left end portions of the grooves 9c and 9d and is also guided to the long grooves 8c and 8d of the first tip guide 8 to be arranged in two rows. That is, the two rows of printing wires are arranged in a staggered manner, but the vertical pitch thereof is the largest. When printing is performed with this arrangement of the print wires, the overlapping amount of dots formed by the adjacent print wires is minimized, so the print density is reduced, but large characters can be printed.

The print density and the size of print characters can be changed as required. That is, the switching lever 12 is appropriately swung to swing the second tip guide 9, and the position of the groove for guiding the print wire 6 is set to, for example, the central portion shown in FIG. If it is moved to the position of the intermediate portion, it is possible to obtain the intermediate print density and the intermediate character size, so that it may be set arbitrarily as necessary.

In order to switch the print wires 6 to the parallel arrangement, as shown in FIG. 7, the shapes of the grooves 19c and 19d formed in the second tip guide 19 are changed to the groove 9 described above.
The shapes are slightly different from those of c and 9d. That is,
The shapes of the grooves 19c and 19d from the left end portion to the middle portion are the same as the shapes of the grooves 9c and 9d, and the shape from the middle portion to the right end portion is slightly curved with the groove 19c.
Then make the curve a little steeper. With such a shape,
When the print wires 6 are guided to the right ends of the grooves 19c and 19d and are also guided to the long grooves 8c and 8d of the first tip guide 8 to be aligned in two rows, the relative positions of the print wires in two rows. Have a parallel arrangement and a small vertical pitch. By arranging the print wires 6 to supply a drive signal for forming different characters to the print wires in each row, the print density is reduced but the print speed is increased.

The number of print wires is not limited to 24, and the number of print wires is not limited to those arranged in parallel in two rows. For example, they may be arranged in a diamond shape or an arc shape. Also,
In the above embodiment, an example in which the second tip guide 9 is oscillated is shown, but the first tip guide 8 side may be oscillated. Further, the long grooves 8c and 8d are not limited to those extending in the vertical direction, but may be inclined and extended. Further, the means for swinging the tip guide is not limited to the above example, and may be switched by using power.

[0026]

As described above, according to the present invention, the two tip guides are stacked in the thickness direction and one of them is swung in the plane direction with one end as the swing center, so that the clearance required for the movement is small. And the relative positional accuracy can be improved. Therefore, since a high degree of dimensional accuracy is not required, the manufacturing is easy, the vertical pitch between the print wires can be changed with a simple structure, and the two rows of print wires can be appropriately set by setting the groove shape. The relative position of can be switched between the staggered arrangement and the parallel arrangement, and the cost can be reduced. Further, the tip guide can be swung easily by the switching lever, and the structure is simple and can be provided at low cost.

[Brief description of drawings]

FIG. 1 is a front view of a printer head according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the central portion of FIG.

FIG. 3 is an enlarged front view of a first tip guide.

FIG. 4 is an enlarged front view of a second tip guide.

5 (a), (b) and (c) are enlarged front views for explaining a state of the print wire guided by the long groove of the first tip guide and the groove of the second tip guide, respectively.

FIG. 6 is a front view showing an example of means for swinging a second tip guide.

FIG. 7 is a partially cutaway enlarged front view showing another example of the second tip guide.

[Explanation of Codes] 1 print head 6 print wire 7 head frame 7a nose portion 8 first tip guide 8c, 8d long groove 9, 19 second tip guide 9c, 9d, 19c, 19d groove 9e driven tooth shape 12 switching lever 12a Drive tooth profile

Claims (4)

[Claims] 1. A wire dot having a print head mounted on a carriage, moved in the width direction of a recording medium, and having a plurality of electromagnetically driven print wires aligned and supported by a nose portion of a head frame. In the printer, the nose portion is provided with first and second tip guides that align the tip portions of the print wires in at least two rows, facing each other in the extending direction of the print wires. At least two long grooves extending in the longitudinal direction are provided in parallel in the guide, a plurality of printing wires pass through the respective long grooves, and the second tip guide is provided with the respective printing wires. A plurality of grooves which can penetrate and are slidable are provided so that the relative position of the print wires in at least two rows or the vertical pitch between the print wires can be changed by the swinging. Is a wire dot printer capable of switching print modes, characterized in that one of the second tip guides is fixed and the other is supported so as to be swingable in the plane direction with one end thereof as the swing center. . 2. The groove of the second tip guide according to claim 1, wherein one end of the groove is provided at a position for guiding the print wires in a zigzag arrangement and at a large vertical pitch, and the other end thereof is the print wire. Are arranged in a zigzag arrangement and at a position that guides at a small vertical pitch, and between the one end and the other end, the print wire is provided at a position that guides at a gradually smaller vertical pitch. A wire dot printer that can switch the print mode. 3. The groove of the second tip guide according to claim 1, wherein one end of the groove is provided at a position that guides the print wires in a staggered arrangement and at a large vertical pitch, and from the one end to a central portion thereof. Between the above, the print wires are arranged in a zigzag arrangement and at a position that guides them in a smaller vertical pitch, and the other end is provided in a position that guides the print wires in a parallel arrangement and at a smaller vertical pitch. A wire dot printer that can switch the print mode. 4. The method according to claim 1 or 3,
A driven tooth profile is provided on the other end of the second tip guide,
A switching lever is provided which has a driving tooth profile that meshes with the driven tooth profile and is swingably supported, and the second tip guide is swung by the swing of the switching lever. Switchable wire dot printer.