JPH02153749A - Impact dot head - Google Patents

Abstract

PURPOSE:To obtain an impact dot head realizing stable printing quality by so arranging a stopper member against which an armature abut during the waiting time of printing as to be supported movably. CONSTITUTION:A stopper member 15 of an impact dot head is engaged with a weight 16, so that the stopper member 15 is made rotatable. When the impact dot head begins to oscillate because of the operation of a main body of the printer, the weight 16 swings by the acceleration of the oscillation. However, since the stopper member 15 is arranged to rotate, the attracting phenomenon between the armature 1 and stopper member 15 due to the oil or ink at the stopper member where the armature 1 abut against separates the armature 1 and stopper member 15. Then, a suction force is generated between a plunger 2 and a yoke 3. Accordingly, the armature 1 projects a printing wire 8 from a guide 9 and the printing wire collides against a platen 12 via an ink ribbon 10 and a recording paper 11, thereby forming dots on the recording paper 11. Therefore, omission of dots or the like can be prevented and stable printing quality can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to stabilizing the print quality of an impact dot head, such as preventing dot removal.

[Conventional impact dot head] As shown in FIG. 5, in the conventional impact dot head, the yoke 5. Phil 5. The armature 1 is driven by a magnetic circuit formed by (1゛q) to cause the printing wire 8 to protrude from the tip of the guide 9, collide with the recording paper 11 via the ink ribbon 10, and transfer the ink. Form a dot.

Before and after this printing operation, the armature 1 waits with the stopper member 65 in contact. However, if the stopper member 35 and the armature 1 are in contact for a long time, oil or ink may enter between the two. This causes a suction phenomenon and the printing wire 8 cannot be sufficiently accelerated, which has the disadvantage of causing dot removal and the like.

[Problems to be Solved by the Invention] It is an object of the present invention to provide an impact dot head that overcomes the above-mentioned drawbacks, does not cause dot removal, and provides stable printing quality.

[Means for Solving the Problems] The impact dot head according to the present invention has a printing wire.
In an impact dot head that includes an armature that urges the printing wire and a coil that magnetically drives the armature, a stopper member that the armature hits during printing standby is supported so as to be interlocked. Furthermore, this stopper member has the following characteristics:
It is characterized in that it is rotatably supported, and further that the stopper member is supported in a linearly movable manner.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the present invention,
A plunger 2 is fixed to an armature 1, and a rotation fulcrum portion 1a is pressed by a fulcrum spring 6, making it rotatable. -Kj of armature 1 has printing wire 8
is pressed by a return spring 7, and the tip of the printing wire 8 can be projected from the guide 9 by driving the armature 1. The magnetic flux generated by the coil 5 wound around the yoke 5 is transmitted to the yoke 6, the side yoke 4. It passes through a magnetic circuit made up of plunger 2. An ink ribbon 10 and recording paper 11 are provided between the printing wire 8 and the platen 120. The armature 1 and the printing wire 8 are pressed against the stopper member 15 by the return spring 7, and a weight 1 is attached to the stopper member 15 held in the standby position.
6 are engaged, allowing rotational movement in the direction shown in FIG.

The operation of the first embodiment will be explained using the above configuration.

Immediately before the printing operation of the impact dot head is started, when the impact dot head starts to swing by the printer body, the weight 16 makes a pendulum motion due to the acceleration of the swing. Since the stopper member 15 engaged with this weight 16 rotates, the armature 1
The attraction phenomenon between the armature 1 and the stopper member 15 due to the oil or ink in the area where the armature 1 and the stopper member 15 are in contact with each other causes a pulling and peeling action. Thereafter, an attractive force is generated between the plunger 2 and the yoke 5 due to the magnetic flux generated by the coil 5, and the armature 1 causes the printing wire 8 to protrude from the guide 9. This printing wire 8 is an ink ribbon 10. It collides with the platen 12 through the recording paper 11, forming dots on the recording paper 11 and printing.

FIGS. 3 and 4 are diagrams showing a second embodiment of the present invention. The difference from the first embodiment is that the stopper member 25 and the weight 26 are capable of linear movement in the direction shown in FIG. The difference in operation is that when the printer body starts swinging the impact dot head just before the printing operation of the impact dot head starts, the weight 26 and the stopper member 25 move linearly due to the acceleration of the swing. This is to remove the attraction phenomenon between the armature 1 and the stopper member 25.

The configuration and operation of the present invention are described in the above-mentioned section 1. The stopper member is not limited to the second embodiment, and the stopper member is
By making the Z-axis movable in all directions, the adhesion phenomenon between the armature and the stopper member can be removed. In addition, as a driving source for moving the stopper member, in addition to the method using the acceleration during the swinging of the impact dot head as in the above embodiment, a method using the displacement of the swinging, a direct drive source such as an electromagnet, a motor, etc. It is also possible to drive it.

[Effects of the Invention] As explained in detail above, according to the present invention, in the impact dot head, by supporting the stopper member so as to be interlocked with each other, it is possible to separate the adhesion between the armature and the stopper member at the start of printing. This has the effect of preventing dots and the like due to insufficient acceleration of the armature and printing wire.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an impact dot head showing a first embodiment of the present invention, FIG. 2 is an explanatory diagram of its operation, FIG. 3 is a cross-sectional view of a second embodiment of the present invention, and FIG. It is an explanatory diagram of the operation. Also, FIG. FIG. 6 is a sectional view and an explanatory view showing a conventional example. 1... Armature 3... Yoke 5... Coil 8... Wire 15.23'', 35...・・Stopper mounting member 1
4.24...Bearing 15.25.35...Stock collar member 16.2
6... Weights Figure 3 Figure 4 Figure 1 Figure 2

Claims (3)

[Claims] (1) In an impact dot head that includes a printing wire, an armature that urges the printing wire, and a coil that magnetically drives the armature, the stopper member that the armature hits during printing standby is movable. An impact dot head characterized by being supported by. (2) The impact dot head according to claim 1, wherein the stopper member is rotatably supported. (3) The impact dot head according to claim 1, wherein the stopper member is supported for linear movement.