JPS60285Y2 - wire dot printer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a wire dot printer, and in particular to an improved structure of a print head mask (hereinafter simply referred to as 1 mask yo) that regulates the distance between the print surface of a print medium and the print head. .

2. Description of the Related Art Wire dot printers have conventionally been used as one of printer devices for outputting processing results of information processing systems.

For example, this wire dot printer prints one character in 5 lines x
It displays a combination of some of the seven rows of dots.

A conventional example of such a wire dot printer is shown in FIG. 1, and this printer has a print head 1 mounted on a carrier 2, which is driven by a space motor 3, a timing belt 4, and a screw rod 5, and is driven by a guide shaft. 6 in the direction of arrow A, print head 1
The ink ribbon 9 and print medium 10 supplied from the ink ribbon cassette 8 provided in the carrier 2 are connected to each other by the dot wire 7 (see FIG. 2, hereinafter simply referred to as "one wire").
The printer is configured to perform printing by hitting the platen 11 with the printer.

The print head 1 is provided on a carrier 2 so as to be movable in the direction of the platen 11 via a movable holding table 1a (see FIG. 3).

For example, one wire magnet assembly as shown in FIG. 2 is housed within the print head 1.

In this assembly, an armature 12 to which a wire 7 is fixed is swingably attached to a support 14 and a guide shaft 15 on a base 13, and is held by a holding spring 16 and a return spring 17.
Apply an upward biasing force to the electromagnet 18 during printing.
When energized, the armature 12 is attracted downward as shown by the dotted line, thereby driving the wire 7 to perform a printing operation.

However, in the above-mentioned printer, the wire of the print head cannot have a very long length due to its driving force, and is generally about one length.

Therefore, it is necessary to bring the print head close to the print surface of the print paper.

For this reason, conventionally, the print head is provided with a mask for regulating the distance between the print head and the printing surface.

Conventional examples thereof are shown in FIGS. 3 and 4.

In the example shown in FIG. 3, the mask 20 is fixedly provided on the head holder 1a.

Note that the ink print head 9 is connected to the print head 1 as shown by the imaginary line.
and the master 20.

When printing on the flat printing surface 21 of the printing medium 10, the lower surface of the mask 20 is in full contact with the printing surface 21, and a distance G is maintained between the print head 1 and the printing surface 21.

The interval G is generally determined to be about 0.5 to 0.6 mm.

On the other hand, the stroke of the wire 7 is set so as to strike the printing surface 21 at a position where the wire's impact force on the printing surface is at its maximum, that is, almost at the final point of the stroke.

However, when the printing medium is, for example, a bank passbook, when opened with different numbers of pages on the left and right sides, a stepped portion 22 appears on the printing surface 21.
In such a case, when the mask 20 is placed on the stepped portion 22, the distance between the print head 1 and the printing surface 21 becomes Gl.
(=G+I~1), and it becomes impossible to print if the wire 7 reaches the printing surface 21.

In order to make this printable, the wire stroke should be set at the interval G1, and the setting deviation should be as small as possible.

This is possible by changing the initial position (return position) of the armature 12 of the wire machinet assembly (FIG. 2) as described above.

However, when the wire stroke is adjusted to the interval G1,
This time, when printing on the flat printing surface, the wire stroke may be too long, or the wire may be placed in the middle of the stroke and the printing impact may be applied, resulting in printing defects such as 1st fade or 1st course. become.

To make this easier to understand, the explanation will be given with reference to FIG. 5, replacing the wheel stroke with the operation of the armature 12 that drives it.

5, the dotted line a indicates the final suction position of the armature 12 corresponding to the final point of the wire stroke, and the solid line indicates the position of the armature 12 set to match the reference spacing G.
Indicates the initial position of

When the electromagnet 18 is excited, the armature 12 receives the maximum attraction force at the attraction position a, and the wire 7 is approximately at this position 13 and hits the printed surface with the maximum impact force.
Good quality printing can be obtained.

On the other hand, a dash-dotted line C indicates the initial position of the armature 12, which is set to match the narrow spacing G1.

When printing on a flat printing surface as described above in this setting state, the wire 7 reaches a position in the middle of its stroke, that is, when the armature 12 is attracted to the position indicated by the two-dot chain line d, the printing surface is printed. to hit.

However, at position d, the suction force acting on the armature 12 is small, and therefore the impact force of the wire on the printing surface is insufficient, resulting in blurred printing.

Moreover, even though the wire 7 hits the printing surface, the armature 12 continues to be attracted from the position d toward the final suction position a, so that the wire is elastically bent, and the armature 12
When the machine returns, the wire bounces back and coast printing is performed.

In order to improve the above-mentioned drawbacks, in the conventional example shown in FIG. 4, the mask 20 is attached to the carrier movable base 2a in a bin 28 so as to be tiltable.

In this case, when the mask 20 rides on the stepped portion 22 of the printing surface 21, it tilts as shown in the figure.
1 is smaller than the distance G1 in the example of FIG.

(G2.:=G+H/2), therefore, the required stroke of the wire 7 [1-] can be made smaller than in the case of the example shown in FIG. (
For example, it can be set at position d) in FIG.

Therefore, in the case of a flat printing surface, the armature position corresponding to the printing striking position of the wire is naturally closer to the electromagnetic force 18 than the position d, and the printing striking force increases.

Moreover, since the remaining stroke of the wire at the time of printing impact becomes smaller, the deflection of the wire is correspondingly reduced, and ghost printing due to bounce of the wire is reduced or weakened.

However, even with J3 in this conventional example, there is a problem that as the print head 1 approaches the stepped portion 22, the interval G2 becomes almost equal to G1, making printing impossible. If the setting is made according to G1, the same problem as in the example shown in FIG. 3 will occur.

Therefore, the purpose of the present invention is to solve the above-mentioned problems, that is, to provide a wire dot printer that is capable of producing commercial quality printing without blurring or ghosting on either the flat or stepped portions of the printing surface. be.

To achieve this purpose, it is necessary to make good use of the wire stroke to print on both flat and stepped portions of the printing surface, and to do so, the distance between the print head and the printing surface must be even. It suffices to make it substantially constant in both the supporting portion and the stepped portion.

Therefore, the present invention generally includes a print head that is mounted on a carrier via a movable head holder and is movable in a direction parallel to a print surface of a print medium and in a direction perpendicular to the print surface; In a wire dot printer, the head is provided with a mask that is tiltable about a pivot axis perpendicular to the direction of circular movement of the head and that comes into contact with the printing surface to regulate the distance between the printing head and the printing surface. , a convex projection is formed on both ends of the mask in a direction of movement parallel to the printing surface of the print head, phantom to the printing surface, and the projection is configured to contact the printing surface. It is.

According to this configuration, the mask can escape the stepped portion of the printing surface through the recessed portion between the two protruding portions, so that the distance between the print head and the printing surface does not differ much between the flat portion and the stepped portion.

Note that the mask must be able to tilt freely depending on the condition of the printing surface, but if it is tilted more than necessary, the ink phone may fly out of the hole in the mask, staining the printing surface, or it may become unstable when adjusting the spacing, making adjustment work difficult. becomes difficult.

It is therefore advantageous to provide an equalizer spring which balances the mask in a neutral tilting position when no external forces are acting on it.

Hereinafter, the present invention will be described in detail based on embodiments with reference to the drawings.

FIG. 6 shows a print head section of an embodiment of the printer according to the present invention in correspondence with FIG. 2 or 3.

The mask 30 according to the present invention is tiltably attached to the head holder 1a via a bracket 31 via a bin 32.

The mask 30 has protrusions 33 and 33 formed at both ends 45 in the moving direction A parallel to the printing surface 21 of the head 1 and projecting from the printing surface.

These protrusions 33 have dimensions such that when the print surface 21 is flat, the lower surfaces of both protrusions 33 come into contact with the print surface 21 to maintain the print head 1 and the print surface 21 at the reference distance G mentioned above. is formed.

On the other hand, if there is a stepped portion 22 on the printing surface 21, one protrusion 33 of the mask 30 will overlap the stepped portion 22, as shown in FIG.
and escapes in the recess between both protrusions 33.

Therefore, the distance G3 between the print head 1 and the print surface 21 is much smaller than the conventional G1 or G2, and is only slightly larger than the reference distance G.

Therefore, by setting the stroke of the wire 7 only slightly larger than the reference stroke, it is possible to completely print on the printing surface 21, including the area near the stepped portion 22.

In the case of such stroke settings, the wire stroke is fully utilized even in printing on the flat portion, and blurred printing and ghost printing are prevented.

In order to make this more clear, the wire stroke will be replaced with the operation of the armature 12 as described above, and the explanation will be made with reference to FIG.

In FIG. 8, lines a and b indicate the final suction position of the armature 12 and the initial position of the armature 12 set to match the reference interval G, respectively, similarly to FIG. 5.

On the other hand, the dashed line e indicates the initial position of the armature 12, which is set to match G3.

This position e is very close to the reference initial position.

When printing on a flat printing surface in such a setting state, the wire 7 performs printing impact when the armature 12 is attracted to a position f (indicated by a two-dot chain line) which is close to the suction position a. .

However, the suction force acting on the armature 12 at position f is very large, almost equal to that at suction position a, so that an effective printing impact force is obtained and no blurring occurs in printing.

Moreover, the remaining stroke of the wire 7 after the printing impact (line a,
(corresponding to the angle between
Ghost printing due to wire bounce does not substantially occur.

Another feature of the mask structure of the present invention is that the bracket 31 is provided with an equalizer spring 35.

The spring 35 is fixed at both ends with pins 36, and the head holder 1
It is arranged so as to be in contact with the end surface of a.

Normally, when no external force is applied to the mask 30, the mask 30 is maintained in equilibrium at its tilting neutral position by the action of the spring 35, and does not tilt freely.

However, as shown in FIG. 7, when a force is applied to the mask 30 to tilt it, the spring 35 is deflected to allow the mask 30 to tilt.

Since the mask 30 is not tilted except when necessary, the ink ribbon 9 (see FIG. 3) is prevented from flying out from the hole of the mask 30, and the printed surface is prevented from becoming dirty.

In addition, it becomes easier to measure and adjust the distance between the printing surfaces of the print head ε.

As described above, the wire dot printer of the present invention has the advantage of being able to print well on both flat and stepped areas of the printing surface by improving the mask, and is extremely practical. It is.

[Brief explanation of the drawing]

Figures 1 to 5 relate to a conventional line of wire dot printers, with Figure 1 being a schematic overall plan view and Figure 2 being a wire dot printer.
Partial cross-sectional views of the ear magnet assembly, Figures 3 and 4.
The drawing is a schematic plan view of the print head section, and FIG. 5 is a diagram for explaining the operation of the armature during printing operation. 6 to 8 relate to an embodiment of the wire dot printer according to the present invention, FIGS. 6 and 7 are schematic plan views of the print head section, and FIG. 8 is a diagram of the armature during printing operation. FIG. 3 is a diagram for explaining the operation. 1...Print head, 2...Carrier,
7... Dot wire, 10... Printing medium, 21... Printing surface, 22... Step portion, 30... Mask, 33... ...protrusion,
35... Equalizer spring.

Claims (1)

[Claims for Utility Model Registration] 1. A print head 1 that is mounted on a carrier 2 via a movable head holder 1a and is movable in a direction parallel to a print surface 21 of a print medium 10 and in a direction perpendicular to the print surface; A mask 30 is provided on the print head so as to be tiltable about a pivot 23 perpendicular to the direction of circular movement of the print head, and comes into contact with the print surface to regulate the distance between the print head and the print surface. In the wire dot printer, the mask 30 in a moving direction parallel to the printing surface of the print head 1
protrusions 33 that are convex with respect to the printing surface 21 at both ends of the
33, and the protruding portion is configured to contact the printing surface. 2 Utility Model Registration Scope In the wire dot printer according to claim 1, when both ends are fixed to the mask 30 and in contact with the end surface of the head holding base 1a, and no external force is acting on the mask 30. A wire dot printer characterized in that an equalizer spring 35 is provided to maintain the same in equilibrium at a tilting neutral position.