JPS5916764A - Printing hammer for printer - Google Patents

Abstract

PURPOSE:To speed up printing as well as raise the stability of printing operations by providing a rigid body whose one end is fixed to a printing wire and the other end is fixed to a bimorph type electrostrictive element and also a stopper to stop the rigid body at a given position when the supply of electricity is interrupted. CONSTITUTION:When voltage is applied to an electrode 2, the tip of a bimorph type electrostrictive element 1 is moved toward the direction of arrow by a flexing force resulting from a reverse voltage effect, and a rigid body 8 is turned clockwise around the corner 7a of a stopper. The displacing amount of the printing wire 3 multiplies the displacing amount of the bimorph type electrostrictive element 1 by b/a times at the corner 7a as a turning fulcrum of the stopper to move it in the direction of arrow A. The printing wire 3 collides on a printing medium through an ink ribbon and is put into printing operation. When the application of voltage to the electrode 2 is removed, the flexion of the bimorph type electrostrictive element 1 is released and the rigid body 8 is turned counterclockwise around the turning fulcrum 7a and restored to the state before the application of voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing machine for a printing device (7'' printer) used for input/output equipment such as information processing.

Serial and 1, which are generally used as printing devices for information processing equipment.
- Printers, line printers, etc. are configured to continuously perform a printing operation by applying an electrical signal to a printing hammer drive circuit, thereby causing the printing hammer to repeat the operation of printing on a printing medium.

As this type of printing hammer, a printing hammer using an electromagnet and a printing hammer using an electrostrictive element have been implemented.

Among these, printing hammers using electrostrictive elements are, as shown in Figure 1, two types of electrostrictive elements or a metal and an electrostrictive element bonded together to form a bimorph type electrostrictive element 1, and a voltage is applied to the surface of the bimorph electrostrictive element 1. A printing wire 3 is fixed to the free end of the bimorph type electrostrictive element, and the other end is fixed by a support member 4 and a support member 5.

When no voltage is applied to the electrode 2, the Guimolar electrostrictive element 1 is stationary. To perform a printing operation, a voltage is applied to the electrode 2. Then, the bimorph electrostrictive element 1 is deflected due to the inverse piezoelectric effect, and the printing wire 3 attached to the tip moves in the direction of the arrow, thereby performing printing on a printing medium (not shown). When the voltage on the electrode 2 is removed, (2) the deflection of the bimorph type electrostrictive element 1 is released, and the printing wire 3 returns to its position when no voltage is applied.

Therefore, in the conventional system, the bimorph type electrostrictive element 1 and the printing wire 3 are treated as one movable body, and when this movable body prints on a printing medium, the rigidity of the bimorph type electrostrictive element 1 is small. Collision causes vibration. This collision vibration is stored in the bimorph type electrostrictive element 1 as part of the kinetic energy possessed by the movable body. Therefore, there is a drawback that the printing force is small compared to the kinetic energy that the movable body had before the collision. Furthermore, due to this small printing force, the repulsive force of the printing wire 30 from the printing medium is also small, so that the recovery speed of the printing wire 3 is slow and the printing speed is slow. Further, there is a drawback that the operation of the printing wire 3 becomes unstable due to collision vibration of the bimorph type electrostrictive element 1.

Furthermore, since the bimorph electrostrictive element 1 generally has a small piezoelectric constant, when applied to a wire print head of a serial printer, etc., the length of the element must be increased (3), which has the disadvantage of increasing external dimensions. However, to compensate for this, it has the disadvantage of requiring a high-voltage power supply.

The purpose of the present invention is to solve these drawbacks by increasing the rigidity of the movable body to reduce collision vibration of the movable body, and to increase printing force, speed, and operation speed compared to the conventional method. In addition to improving stability, the displacement amount of the printing wire expands the displacement amount of the bimorph type electrostrictive element, and will be described in detail below.

FIG. 2 is a side sectional view showing the first embodiment of the present invention.
The same parts as those in the figure are given the same numbers.

In the figure, 6 is an L-shaped support member that clamps one end of the bimorph electrostrictive element 1 in cooperation with the support member 5, 7 is a stopper supported at the tip of this support member 7, and 8 is the bimorph electrostrictive element 1. The copper body 8 has one end supported by the other end of the strain element 1, and the printing wire 3 is fixed to the other end of the copper body 8.

Still, the stone rod 7 is fixed to the support member 6 (4) so as to come into contact with approximately the center of the copper body 8, and the corner 7a of the stone rod 7 is the rotation fulcrum of the copper body 8. It is configured so that.

In the printing hammer configured as described above, when no voltage is applied to the electrode 2, the rigid body 8 is stopped at a position determined by the stopper 7. Then to get this to work,
By applying a voltage to the electric field 2, the tip of the bimorph electrostrictive element 1 moves in the direction of the arrow (downward) due to the deflection force due to the inverse piezoelectric effect. Therefore, the copper body 8 is the stone i4
rotates clockwise around corner 7a. At this time, from the corner 7a of the stone, the rigid body 8 and the bimorph type electrostrictive element 1
If the distance at the fixed neck of the stopper is a, and the distance from the corner 7a of the stopper to the rigid body 8 and the fixed part of the printing wire 3 is b, then the amount of displacement of the printing wire 3 is calculated from the corner 7a of the stopper as the rotational fulcrum. Then, the displacement amount of the bimorph type electrostrictive element 1 is expanded by a factor of b/a, and the bimorph type electrostrictive element 1 is moved in the direction indicated by the arrow. The printing wire 3 collides with a print medium (not shown) via an ink ribbon (not shown) to perform a printing operation. When the application of voltage to the electrode 2 is removed, the deflection of the bimorph electrostrictive element 1 is released, and the rigid body 8
rotates counterclockwise about the rotational fulcrum 7a, returns to the state before voltage application, and completes the printing operation.

As explained above, in the first embodiment, the corner 7a of the stopper is located at the middle part of the rigid body 8 to which the printing wire 3 is fixed.
Since the structure operates with the rigid body 8 as a rotational fulcrum,
The printing wire 3 will be referred to as a movable body. The operation of the printing wire 3 when printing on a printing medium (not shown) is determined by this movable body, and the rigidity of the movable body is high. Therefore, the bimorph type electrostrictive element 1 is unlikely to cause collision vibration, so there is no loss of kinetic energy that the movable body had before the collision, and the printing force has the advantage of being greater than that of conventional devices. . In addition, because of the large printing force, the repulsive force of the printing wire 3 from the printing medium is also large, so there is an advantage that the recovery speed is fast and the printing speed is fast. Furthermore, the bimorph type electrostrictive element 1 has the advantage that the printing wire 3 can operate stably because no collision vibration occurs.

Next, Figure 3 shows how to use the printing hammer shown in Figure 2 in a serial manner.
A conceptual diagram when applied to a print head of a printer is shown.

As shown in FIG. 3, a wire guide 11 converges several to several dozen radially arranged printing nozzles and their printing wires 3, and the tips of the printing wires 3 are aligned in a straight line. The wire guide 9 includes a frame 10 for fixing these wire guides.

By arranging the printing hammers in a radial manner in this manner, it is possible to integrally process the stopper 7, the support member 6, etc., thereby improving processing accuracy and reducing manufacturing costs. Further, since the stop position of the rigid body 8 is determined by the stopper 7, it becomes easy to make the lengths of the printing wires 3 uniform.

FIG. 4 is a side view showing another embodiment according to the present invention.

In the embodiment shown in FIG. 4, the rigid body 8 is L-shaped.
This makes it possible to arrange the semi-flexible electrostrictive elements 1 in a direction perpendicular to the rigid body 8, and when applied to a printing wire head of a printer such as a serial printer,
The outer dimensions of the head are small, making it easier to see printed characters and improving visibility. If the external dimensions are the same, the distance Mb described above can be increased, so the amount of displacement of the bimorph element 1 may be small. Therefore, the voltage applied to the bimorph element 1 can be reduced. This has the effect of not requiring a high voltage power supply.

FIG. 5 is a side view showing still another embodiment of the present invention. In FIG. 5, a round bar is passed through the middle part of the rigid body 8, and this is used as a rotation fulcrum 12, and the rigid body 8 and the bimorph type electrostrictive element 1 are arranged in parallel, thus making the device even smaller than the embodiment shown in FIG. becomes possible.

The present invention has a printing hammer that drives a printing wire by the deflection force due to the inverse piezoelectric effect of a bimorph electrostrictive element, and is configured to be rotatable as a center of rotation at the middle part of a rigid body with a printing wire fixed to the tip. Bimorph type electrostrictive elements do not produce collision vibrations, so they have the advantage of high printing speed, stable operation, and a printing hammer with high printing force.
It is extremely useful as a print head for high-speed dot printers.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of a conventional printing hammer, Fig. 2 is a side view showing the first embodiment of the present invention, and Fig. 3 is an example of the printing hammer shown in Fig. 2 applied to a serial printer. FIG. 4.5 is a partially cutaway side view of the second and third embodiments. 1... Bimorph type electrostrictive element, 2... Electrode, 3...
・Printing wire, 4, 5.6... Support member, 7...
Stopper, 8...rigid body. Patent applicant Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] One end of the bimorph electrostrictive element is fixed, and a printing wire is provided approximately vertically on the free end side, and the bimorph electrostrictive element is energized to produce the printing by the bending force due to the reverse voltage effect of the bimorph electrostrictive element. A printing hammer that drives a wire includes a rigid body having one end fixed to the printing wire and the other end fixed to the bimorph electrostrictive element, and a rigid body that A printing hammer for a printer, comprising: a stopper for stopping the hammer at a predetermined position; and a substantial pivot point for the rigid body.