JPS5945165A - Impact type printing head - Google Patents

Abstract

PURPOSE:To miniaturize an impact type printing head as well as reduce the consumption of power by a method in which the printing head is made up of a piezo-electric element to generate dimensional strains, a wire to make printing by receiving the striking force, and a spring to press the coupling part on the power transmission part. CONSTITUTION:When a drive voltage is applied to an electrode 5, a piezoelectric element 4 extends in the direction of arrow A as shown by a broken line. A dimensional strain is then generated in the element 4, a striking force acts on the coupling part 14 of a wire 10 through a power transmission part 8, and the wire 10 slides along a guide hole 12 and moves in the direction of arrow B as shown by broken line for printing action. Afterwards, the wire 10 and the coupling part 14 are returned to the position at the time of non-printing by the compression stress of the coil spring 16. Since the piezo-electric element 4 is used as the drive means of the wire, the size of the printing head can thus be miniaturized as compared with the conventional ones, and the consumption of electric power can also be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to impact printheads, and more particularly to impact printheads for driving free-flight wires to print dots.

Conventionally, a so-called clapper-type impact print head, which uses an electromagnet as a driving means to drive a free-flight wire to print dots, has been used in dot impact printers. This clapper type print head has the advantage that a long stroke can be obtained because the driven wire flies to print.

However, conventional impact print heads have disadvantages of large size and high power consumption because they use electromagnets.

An object of the present invention is to eliminate the above-mentioned drawbacks and provide an impact print head that is smaller and consumes less power than conventional ones.

The print head of the present invention includes a piezoelectric body that generates dimensional distortion due to the piezoelectric longitudinal effect, a mounting member that mounts and supports one end of the piezoelectric body, and a mounting member that is connected to the other end of the piezoelectric body to prevent the dimensional distortion. a force transmitting member that generates displacement in accordance with the movement; a guide member that is supported by the mounting member and has guide holes at predetermined locations; The force transmitting device includes a wire passed through the guide hole and a spring installed between the guide member and the mooring portion to press the mooring portion to a predetermined location of the force transmitting member by elastic force. and a printing member that moves in a predetermined direction according to the displacement given from the previous month.

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

FIGS. 1(a) and 1(b) are a perspective view and a partial side view, respectively, showing a first embodiment of the present invention. The same figure (a
), one end of a piezoelectric body 4 is fixed to a metal or plastic mounting member 1. Conductive wires 6 are connected to a pair of electrodes 5 provided on both sides of the piezoelectric body 4, and when a driving voltage is applied through the conductive wires 6, the length of the piezoelectric body 4 increases due to the piezoelectric longitudinal effect, causing dimensional distortion. arise.

Eight force transmitting members made of metal or plastic are fixed to the other end of the piezoelectric body 4. A wire guide 2 having a guide hole 12 through which the wire 10 can slide is fixed to the upper part of the member 1. A disk-shaped anchoring portion 14 is provided at one end of a metal wire 10 for printing dots. The mooring portion 14 of the wire 10 passed through the guide hole 12 is pressed onto the surface of the force transmitting member 8 by the compressive stress of the coil spring 16 attached around the wire 10 between this and the wire guide 2. It is in the position when no printing is done.

FIG. 1(b) shows a case where the piezoelectric body 4 shown in FIG. 1(a) expands in response to the driving voltage applied to the electrode 5. In FIG. When the piezoelectric body 4 stretches in the direction indicated by the broken line arrow A and causes dimensional distortion,
An impact force acts on the anchoring portion 14 of the wire 10 via the force transmitting member 8, and the wire 10 slides along the guide hole 12 and moves in the direction of the broken line arrow B, thereby performing a printing operation. Thereafter, the wire 10 and the anchoring portion 14 return to their non-printing positions due to the compressive stress of the coil spring 16.

Since the piezoelectric body 4 is used as the wire driving means, the print head of this actual bill example can be made smaller and consume less power than conventional ones. Further, in this embodiment, the force transmitting member 8 has a simple structure that directly transmits the dimensional strain occurring in the piezoelectric body 4 to the wire 10, and has the advantage of being easy to manufacture.

FIG. 2 is a perspective view showing a second embodiment of the invention. In the print head shown in the figure, the piezoelectric body 4 is transferred to the wire 10 by a force transmitting means comprising first and second coupling members 20 and 22 and a movable member 24 instead of the force transmitting member 8 in FIG. Magnifies and transmits dimensional distortion. That is, when a driving voltage is applied to the electrode 5 through the conductor 6, the piezoelectric body 4
extends in the direction of the broken line arrow A to generate dimensional distortion, and this dimensional distortion is transmitted to the movable member 24 via the first coupling member 20 fixed to the upper end of the piezoelectric body 4. Since the movable member 24 is connected to and supported by the mounting member 1 via the second coupling member 22 provided at a predetermined distance from the first coupling member 20, the rotational moment is generated in accordance with the transmitted dimensional strain. will occur. Along with this, the tip moves in the direction of the broken line arrow C and applies an impact force to the mooring portion 14 of the wire 10.
perform printing operation. In this way, the movable member 24 uses the second coupling member 22 as a support point and acts as a lever to magnify the dimensional strain transmitted from the first coupling member 20. The piezoelectric body 4 is
By enlarging the dimensional distortion that occurs in the wire 10 and transmitting it to the wire 10, it is possible to lengthen the contact time when the movable member 24 applies impact force to the mooring portion 14 of the wire 10, and as shown in FIG.
Since a longer printing stroke can be obtained than in the case of the printing head shown in a), it is possible to shorten the length of the piezoelectric body 4 required to obtain a printing stroke of the desired length, thereby making it possible to downsize the printing head. There are advantages.

Note that the support member 8 supporting the lower end of the piezoelectric body 4 on the support part shrine 1 is provided to prevent the piezoelectric body 4 from receiving an excessive bending moment during operation.

FIGS. 3(a) to 3(f) are side views showing a configuration example of a force transmitting means having a lever action in the second embodiment.

In each of the same figures (a) to (f), the lever L indicates the movable member 24 in FIG. 2, and one of the coupling pieces P and Q connects the first coupling member 2o, and the other Member 22 is shown. For example, the connecting piece P (or Q) in FIG.
If the coupling piece Q (or P) is used as the first coupling member 20 and a dimensional strain is applied to it in the direction of arrow G, the tip of the lever L moves in the direction of arrow H1 (or dashed arrow H2). The force transmitting means for printing characters shown in Fig. 2 (a)
) is applied to make the coupling piece P the first coupling member 2° and the coupling piece Q the second coupling member 22.

Other application examples can be easily obtained from the above explanation, two of which are shown below.

FIGS. 4(a) and 4(b) are side views showing third and fourth embodiments of the present invention, respectively. For ease of contrast between the drawings, parts having the same function are given the same reference numerals as in FIG. 2, even if their shapes are different. In the force transmitting means of the print head shown in FIG. 3(a),
) is applied, and the connecting pieces P and Q are used as the second and first connecting members 22 and 20, respectively. The same figure (b
), applying the configuration shown in FIG. 3(f), connecting pieces P and Q
are the first and second coupling members 2o and 22, respectively. In either case, the dimensional strain produced in the piezoelectric body 4 in the direction of the broken line arrow 9-A is transmitted in an enlarged manner by the force transmitting means with lever action, causing the wire 1o to move in the direction of the broken line arrow B. Perform printing operation. Therefore, as in the case of the second embodiment, the print stroke can be lengthened and the print head can be made smaller.

FIG. 5 is a perspective view showing a fifth embodiment of the present invention. The force transmitting means in the print head shown in the figure are the first to fourth force transmitting means.
It is composed of coupling members 30, 32, 34 and 36, first and second movable members 35 and 37, and a flexible member 38. The first and second coupling members 30 and 32 fixed to the upper end of the piezoelectric body 4 transfer the dimensional strain in the direction of the broken line arrow A generated by the piezoelectric body 4 to the first and second movable members 35 and 32, respectively. 37. Accordingly, a rotational moment is generated in the first and second movable members 35 and 37 supported via the third and fourth coupling members 34 and 36, respectively, and the first and second movable members The upper ends of 35 and 37 move in the directions of dashed arrows C and D, respectively. First and second movable members 3
5 and 3610-, a flexible member 38, which is a leaf spring with a recessed part in the center, is attached, and the mooring part 14 of the wire 10 is attached to the upper surface of the four parts by the elastic force of the coil spring 16. It is pressed by. First and second movable members 35 and 37
When the upper ends of move in the directions of dashed arrows C and D, respectively,
In response to this, the central concave portion of the flexible member 38 is pulled from both sides and elastically deforms in the direction of the broken line arrow E, applying impact force to the mooring portion 14 of the wire 10, causing the wire 10 to perform printing in the direction of the broken line arrow B. Have them do it. In this way, the first and second movable members 35 and 37 expand the dimensional strain of the piezoelectric body 4 by lever action and transmit it to the flexible member 38.
A longer printing stroke can be obtained than in the case of the printing head of a), and the length of the piezoelectric body 4 required to obtain a desired length of printing stroke can be shortened, and the printing head can be made smaller.

FIGS. 6(a) and 6(b) are perspective views showing examples of the structure of the piezoelectric body 4 in the first to fifth embodiments.

In both cases, a plurality of electrodes 51 and 52 are arranged alternately in parallel within the piezoelectric body 4, and the electrode 51 is connected to one of the pair of electrodes 5 provided on the side surface, and the electrode 52 is connected to the other. Figure (a) shows a case where a piezoelectric material such as zircon/lead titanate is used. The piezoelectric material between t'IjM51 and 52 is polarized in a predetermined direction, for example in the direction of arrow F. A driving voltage is applied through the conductive wire 6 so that an electric field in the same direction (or in the opposite direction) as the polarization is applied to the piezoelectric material between the electrodes 51 and 52. , 5, the piezoelectric body 4 causes distortion in its elongation (or contraction) dimension due to the piezoelectric longitudinal effect. Therefore, the direction of dimensional distortion can be selected by selecting the polarity of the drive voltage.

Figure (b) shows a case where an electrostrictive material such as manganese lead niobate is used; in this case, the piezoelectric body 4 stretches regardless of the polarity of the applied driving voltage, causing dimensional distortion; It has the advantage of operating with little hysteresis.

By arranging the plurality of electrodes 51 and 52 in groups of 3 to provide a multilayered internal electrode as described above, it is possible to lower the driving voltage required to obtain a desired size of dimensional distortion. , the driving voltage supply circuit (not shown) can be made compact with a simple circuit.

In the first to fifth embodiments, the piezoelectric body 4 expands and causes dimensional distortion when a driving voltage is applied, but on the contrary, the piezoelectric body 4 shrinks and causes dimensional distortion. It is clear from the above description that a print head can be configured to drive the wire 10.

As explained above, the present invention realizes an impact print head that is smaller and consumes less power than conventional ones by transmitting the dimensional strain that occurs in the piezoelectric body and driving the free-flight print wire. There is an effect that it can be done.

[Brief explanation of the drawing]

Figure 1(a), Figure 2, Figure 5 and Figure 6(a),
(b) is a perspective view showing an embodiment of the present invention, FIG. 1(b)
, Figures 3(a) to (f) and Figure 4(a) l (b
) is a side view showing an embodiment of the present invention. 1...Mounting member, 2...Wire guide, 4...Piezoelectric body, 5.51.52・°゛°°°
°°°electrode゛...conducting wire, 13-8...force transmission member, 10...wire,
12... Guide hole, 14... Mooring part,
16... group coil spring, 18... support member,
20, 22, 30, 32゜34.36゛゛°°°゛Connecting part system, 24.35.37...Movable member, 38.
...Flexible member. Agent Patent Attorney Susumu Uchihara 14- 2nd (ρ) (b) (e) (σ) (C) (J) 73 Figure/h, 5 Kasumi (θ) (b) Life 6 mouth

Claims (6)

[Claims] (1) A piezoelectric body that generates dimensional distortion due to the piezoelectric longitudinal effect, a mounting member that mounts and supports one end of the piezoelectric body, and a mounting member that is connected to the other end of the piezoelectric body and that generates dimensional distortion according to the dimensional distortion. A force transmitting member that causes displacement, a guide member supported by the mounting member and having a guide hole at a predetermined location, one end of which is provided with a mooring portion of a predetermined shape, and the other end of which is provided with a mooring portion of a predetermined shape. The force transmitting device includes a wire passed through the guide hole and a spring installed between the guide member and the mooring portion to press the mooring portion to a predetermined location of the force transmitting member by elastic force. An impact print head comprising: a print member that moves in a predetermined direction in response to the displacement given by the member. (2) The impact print head according to claim (1), wherein the force transmitting member has a columnar shape and its bottom surface is fixed to one end of the piezoelectric body, so that the displacement generated on the top surface of the force transmitting member is applied to the printing member. . (3) The force transmission member is connected to a first coupling member connected to one end of the piezoelectric body and a second coupling member connected to a predetermined location of the mounting member, and the force transmission member Claim 1, further comprising: a movable member that applies a displacement to the printing member that occurs in response to the dimensional strain transmitted through the printing member.
Impact print head described in ). (4) The force transmitting member includes first and second coupling members each connected to one end of the piezoelectric body, and third and fourth coupling members respectively connected to the first and second predetermined locations of the mounting member. a first movable member connected to a coupling member and the first and third coupling members and generating a first angular displacement in response to the dimensional strain transmitted through the first coupling member; a second movable member connected to the second and fourth coupling members to produce a second angular displacement in response to a dimensional strain transmitted through the second coupling member; one end is fixed to a predetermined location of the first movable member, and the other end is fixed to a predetermined location of the second movable member, and the first end is fixed to a predetermined location of the second movable member.
and a flexible member that applies a displacement to the printing member that occurs in response to the second angular displacement. (5) The piezoelectric body has a portion made of a piezoelectric material in which a plurality of electrodes are arranged alternately, and polarization treatment is performed in a predetermined direction between the electrodes. Impact print head as described in section. (6) The piezoelectric body has a portion made of an electrostrictive material in which a plurality of electrodes are alternately arranged.
Impact print head described in ).