JPS6031976A - Impact printing head - Google Patents

Abstract

PURPOSE:To reduce the size of an impact printing head and enable to reduce power consumption, by a construction wherein a plurality of printing units using longitudinal piezoelectric effect type piezoelectric elements are stacked in two blocks. CONSTITUTION:A plurality of printing units comprising the longitudinal piezoelectric effect type piezoelectric elements 4 as drive sources are divided into two blocks, the units in each of the blocks are stacked on a head base 72, and each of wires 11 is guided by aligning members 73-75 provided on the base 72. The printing units in each of the blocks are arranged in a radial manner through spacers 77, and are fitted to the base 72 through a spacer 78 so that the printing units in each of the blocks are led into gaps of fitting members 3 in an alternately staggered manner. Accordingly, the height of the printing head is reduced, the width of the head is also reduced, and the size of the head is reduced. In addition, since the longitudinal effect type piezoelectric elements are used, it can be contrived to reduce power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to impact printheads, and particularly to impact printheads used in dot impact printers.

Conventionally, impact print heads have been used as print heads for dot impact printers, which perform printing operations by utilizing dimensional distortion caused by piezoelectric transverse effects of piezoelectric or electrostrictive ceramics.

FIGS. 1(a) and 1(b) are a perspective view and a side view, respectively, of a conventional impact print head.
), a plurality of printing units 1 are arranged and attached to one end of a head stand 2, and a wire 11 fixed to the end of each printing unit 1 is provided at the other end of the mounting member 2. They are constructed by passing through guide holes in the member 21 and aligning them. Each printing unit) IVi, as shown in the same figure (+)), piezoelectric plates 41 and 42 are fixed to both sides of a conductor electrode plate 500, and conductor electrode plates 51 and 52 are fixed to the inner and outer surfaces respectively. A wire 11 for printing dots is attached and fixed to one end of the vibrator. The N& plates 51 and 52 are connected to a pair of conductive i! plates via the metal mounting member 2. ! 6, and the electrode plate 5o is connected to the other conductive wire 6. Piezoelectric plates 41 and 4
2 has been subjected to polarization treatment in advance, and the electrode plates 51 and 5
When a driving voltage is applied between the conductive wire 6 and the electrode plate 5o, the piezoelectric plate 41 contracts due to the piezoelectric transverse effect, causing distortion in the direction of the broken line arrow, and one piezoelectric plate 42 expands. This causes distortion in the direction of the dashed arrow B. Along with this, the piezoelectric vibrator is deflected, and the wire 11 moves in the direction of the broken line arrow C, thereby performing a printing operation of striking dots on the printing surface.

As explained above, conventional impact print heads have the disadvantages of large size and high power consumption. In other words, the printing unit used in conventional impact print heads performs printing operations by generating dimensional distortion in the piezoelectric body using the piezoelectric transverse effect, but the piezoelectric transverse effect uses the piezoelectric longitudinal effect. Compared to the case of need to be,
In addition, since the electromechanical coupling coefficient is small, a large surface dynamic force (approximately 5 times as much power) is required to obtain a predetermined strain. In the conventional impact print head equipped with a plurality of printing units 1 that utilize the piezoelectric transverse effect, each printing unit 1 is large as described above, and each printing unit y)i
They must be arranged with a sufficient distance from each other so that they come into contact with other printing units, )l during printing operations, and an increase in the size of the print head is unavoidable.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an impact print head that is compact and consumes less power.

The print head of the present invention includes a piezoelectric body that generates dimensional strain due to the piezoelectric longitudinal effect, a transmission mechanism that transmits the dimensional strain to generate displacement in a predetermined direction, and one end of the transmission mechanism that is fixed to a predetermined location. a plurality of printing units each having a thin rod-shaped wire member that performs a printing operation in accordance with the displacement; The wire members of each of the printing units divided into two sets each having a predetermined number of wire members are arranged at a predetermined angle of inclination to each other, and each tip is inserted into the guide hole, one wire member at a time. Each set of printing units passed through each set forms two printing unit blocks stacked in the thickness direction, and the two printing unit blocks are connected to a gear between the printing unit and , a head stand having a holding member for holding the printing units of both blocks by alternately inserting them therein and overlapping them at locations where the print unit is larger than the thickness of the printing unit.

5- Next, the present invention will be described in detail with reference to the drawings.

FIG. 2 and FIGS. 3(a) and 3(b) are a side view, a top view, and a side view, respectively, showing an embodiment of the present invention. FIG. 2 shows an example of the configuration of a printing unit used in this embodiment. The piezoelectric body 4, which is a driving source for printing operation, has a plurality of internal electrodes 42 arranged in a piezoelectric material 41 at predetermined intervals.
A pair of external electrodes (not shown) are provided on the side surfaces of the piezoelectric body 4, and every other internal electrode 42 is connected alternately to one and the other of the pair of external electrodes. .

When a driving voltage is applied between the external electrodes, this voltage is applied between the internal electrodes 42, and the piezoelectric body 4 is expanded due to the piezoelectric longitudinal effect, causing dimensional distortion. The lower end of this piezoelectric body 40 is attached to the mounting member 3
The upper end of the piezoelectric body 4 is connected to the first and second movable members 5 and 7 via a plate-shaped coupling member. The lower ends of the first and second movable members 5 and 7 are
Furthermore, it is connected to the mounting member 3 via a plate-shaped coupling member.

The mounting member 3 is integrally formed of metal together with the movable members 5 and 7, and is provided with a screw hole 12 for passing a screw 6- through when assembling it into a print. 1st and 2nd
One ends of first and second transmission members 8 and 9 made of metal plates are fixed to the upper ends of movable members 5 and 7, respectively, and the other ends of the first and second transmission members 8 and 9 are The metal third movable member io is fixedly attached to a predetermined location. A printing wire 11 is fixedly attached to the tip of the third movable member 10. When the dimensional strain that occurs when a driving voltage is applied to the piezoelectric body 4 is transmitted to the first and second movable members 5 and 7, they act as levers, so there are dashed arrows and dashed arrows at their upper ends, respectively. E
This causes a displacement in the direction of . These two mutually opposite displacements are transmitted to the third movable member 10 via the first and second transmission members 8 and 9, giving a rotational moment. Along with this, the wire 11 moves in the direction of the broken line arrow F to perform a printing operation. By using the piezoelectric longitudinal effect type piezoelectric body 4 as a drive source in this manner, it is possible to realize a printing unit that is smaller and consumes less power than conventional print heads.

3(a) and 3(b) show an impact print head constructed by incorporating a plurality of printing units (13 in this embodiment) shown in FIG. 2.The plurality of printing units are divided into two sets ( In this embodiment, the printing units are divided into 6 and 7 units), and the printing unit is divided into 6 and 7 units.

They are stacked on top of the print base 72 to form a printing unit and a print unit. A first alignment member 73 is provided at one end of the head stand 72 for guiding the wire 11 to the printing surface.
The alignment member 73 is provided with an outer guide hole through which the wire 11 can slide. In this embodiment, the first alignment member 73
In addition, in order to prevent the wire 11 from generating unnecessary vibration and coming into contact with each other during the printing operation, causing printing errors, a second
and third alignment members 74 and 75 are provided.

If unnecessary vibration of the wire 11 can be prevented by appropriately selecting the dimensions of the wire il, printing speed, etc., the alignment members 74 and 75 can be omitted. The alignment members 74 and 75 are also provided with guide holes through which the wires 11 are passed.

When assembling each professional printing unit into the head stand 72, the distance between the tips of the wires 1N is apparently narrow compared to the thickness of the printing unit, so as shown in the same figure (b), the printing unit The mounting members 3 are arranged radially on the same dirt floor adjacent to each other so as to have an inclination angle in the thickness direction. That is, the guide holes of the alignment members 73, 74 and 75 are provided to guide the wires 11 radially toward the printing surface, and there are no holes between the head stand 72 and the mounting member 3 of the lowermost print head. A spacer 78 having a screw hole for passing the screw 76 and a screw hole for passing the screw 79 is inserted, and a spacer 77 having a screw hole for passing the screw 76 is inserted between each printing unit.
The printing units are arranged radially when viewed from the side, and the screws 76 are inserted into the screw holes 12 and spacers 7 shown in FIG.
At the same time, insert the screw 79 into the screw hole of the spacer 78, pass it through the screw hole provided in the base 72, and tighten the nut at the upper end to hold each set of printing units. Tighten and attach each set of printing units to stand 7.
2. Hold it on top. As shown in the same figure (at), the two sets of printing unit blocks are arranged so that they are symmetrical on both sides with respect to the center line that is approximately parallel to the 9-wire 11. By doing so, the printing units of the two sets of blocks are inserted alternately at the location where the gap between the mounting members 3 of each block is wider than the thickness of the mounting member 3, thereby shortening the width of the printing head. There is.

In this embodiment, by using a piezoelectric longitudinal effect type piezoelectric body 4 as a driving source, the printing unit is made smaller and consumes less power than the conventional printing unit. Furthermore, the height of the print head can be shortened by dividing the plurality of printing units into two sets of blocks and stacking them, and the width of the print head can be reduced by inserting part of the print units of the two sets of blocks alternately. shorten,
By eliminating extra empty space as much as possible, the volume occupied by the print head is smaller than before.

Note that the structures of the printing unit and head stand 72'PL of this embodiment are not limited to these. A piezoelectric longitudinal effect type piezoelectric body is used as a drive source, and the shape and interconnection relationship of the mechanism that transmits the generated dimensions to the wire are changed as appropriate, or the shape of the head stand and the two sets of printing unit blocks are changed. It is easy to change the mounting method as appropriate, and it is clear that the same effects as in this embodiment can be obtained even in this case.

From the above description, it is clear that the present invention has the effect of realizing an impact print head that is smaller and consumes less power than the conventional one, and this effect is particularly noticeable when applied to a case where the number of wires is large.

[Brief explanation of the drawing]

Figures 1 (al and b) are a perspective view and a side view showing a conventional impact print head, respectively, and Figures 2 and 3 (a) and (b) are side views showing an embodiment of the present invention, respectively. and a top view and a side view. 3...Mounting member, 4...Piezoelectric body, 5,
7.10...Movable member, 8.9...Transmission member, 11...Wire, 72---Head stand, 73-75... ...Alignment member, 77.78
...Spacer, 76.79...11
−! ! (71) f (b) No. l closed

Claims (1)

[Claims] A piezoelectric body that generates dimensional strain due to a piezoelectric longitudinal effect, a transmission mechanism that transmits the dimensional strain to generate displacement in a predetermined direction, and one end of which is fixed to a predetermined location of the transmission mechanism. a plurality of printing units each having a thin rod-shaped wire member that performs a printing operation in accordance with the displacement; and at least one printing unit provided with a guide hole through which a tip end of each wire member of the printing unit can slide. an alignment member;
The wire members of the printing units of each set are divided into two sets each having a predetermined number of wire members, and the wire members of each set are arranged at a predetermined angle of inclination to each other, and each of the wire members of each set is passed through the guide hole one by one. Each set of printing units is stacked in the thickness direction to form two printing unit blocks, and the gap between the printing units is larger than the thickness of the printing units. An impact print head comprising: a head stand having a holding member for alternately inserting the printing units of both blocks at certain points and holding the printing units in an overlapping manner.