JPH061047A - Print head - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a print head for an impact printer, and an object thereof is to provide a print head capable of reducing noise leaking out of the head. The print head is provided between the piezoelectric element 5, an armature 6 having a wire 9, and between the piezoelectric element 5 and the armature 6. The displacement of the piezoelectric element 5 when a voltage is applied is transmitted to the wire 9 for printing. The piezoelectric actuator assembly 3 including the enlarging mechanism section 7 to be performed is fixed in the heat sink 24. The heat sink 24 has a double structure in which a hollow portion 27 is formed between an inner cylinder 25 and an outer cylinder 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head for an impact printer.

Impact printers have been widely used mainly in business courses because of their low running costs, but they have the disadvantage of producing loud print noises. Therefore, in order to further popularize and expand this type of printer device, it is necessary to realize low noise, and it is expected that demand for personal use will be generated by realizing this.

[0003]

2. Description of the Related Art FIG. 7 is a side view showing the structure of a conventional piezoelectric print head. In the figure, 1 is a nose, 2 is a heat sink which is an outer enclosure, and a piezoelectric actuator assembly 3 is mounted in the heat sink 2. Although not shown, the piezoelectric print head is mounted on a carrier that can move along the platen and operates while moving with the carrier to perform printing. Configuration of the piezoelectric actuator assembly 3,
The operation is as follows.

In the piezoelectric actuator assembly 3, a plurality of laminated piezoelectric elements 5 are mounted on a common base 4 at a predetermined pitch in the circumferential direction, and an armature 6 and an enlarging mechanism section 7 corresponding to each piezoelectric element 5 respectively. And are provided. The piezoelectric element 5 is attached by fixing the base block 8 fixed to the lower part to the base 4 with an adhesive or the like.

The armature 6 is formed by integrally connecting a beam 10 having a wire 9 fixed at its tip to a base 11. The enlarging mechanism 7 is composed of a support spring 12 and a movable spring 13 which are arranged substantially in parallel. Both ends of the support spring 12 are fixed to the base 11 and the base 4, and both ends of the movable spring 13 are fixed to the base 11 and the block 14 (separate from the base 4).

At the time of printing, a voltage is applied to a predetermined piezoelectric element 5 via the connector 15. As a result, the piezoelectric element 5 is displaced upward and pushes up the movable spring 13. Then, the armature 6 is rotated in the direction of arrow A by the action of the enlargement mechanism portion 7, and the enlarged displacement is transmitted to the wire 9. As a result, the wire 9 moves in the direction of arrow B by a predetermined amount and printing is performed. The movement of the wire 9 is guided by the nose 1.

Since the voltage application to the piezoelectric element 5 is cut off at the time of completion of printing, the wire 9 which has completed printing returns to the original state together with the armature 6, the support spring 12, the movable spring 13, and the piezoelectric element 5. . In addition, each connector 15
Are connected to a common connector 17 via a printed board 16, and power is supplied to the piezoelectric element 5 via the connector 17.

[0008]

In the above print head,
It does not have a special structure for the purpose of reducing noise, but it aims to reduce noise by attaching soundproofing and vibration-proofing material to the housing side of the printer. However, since the impact sound generated inside the head is magnified by the vibration of the head member and the printer housing, there is a problem that the conventional soundproofing technology cannot be expected to have a sufficient effect.

An object of the present invention is to provide a print head capable of reducing noise leaking out of the head.

[0010]

In order to achieve the above object, the present invention comprises a plurality of piezoelectric elements and a plurality of armatures provided corresponding to the respective piezoelectric elements and having wires. In a print head in which a piezoelectric actuator assembly for expanding the displacement of the piezoelectric element when a voltage is applied and transmitting the wire to the wire to perform printing is fixed in a heat sink, the heat sink includes a space between an inner cylinder and an outer cylinder. The structure (first structure) is characterized by having a double structure in which a hollow portion is formed.

A sound absorbing material filled in the cavity is added to the print head of the first structure (second structure).

Further, it is configured to include a plurality of electromagnet mechanisms and a plurality of armatures provided to face each of the electromagnet mechanisms and provided with wires, and the wires are operated by the rotation operation of the amateurs by the operation of the electromagnet mechanisms. In a print head in which an actuator assembly for performing printing is fixed in a heat sink, the heat sink has a double structure in which a hollow portion is formed between an inner cylinder and an outer cylinder. (Third configuration).

A sound absorbing material filled in the cavity is added to the print head of the third structure (fourth structure).

[0014]

In the first and third configurations, the vibration (noise) generated by the collision of the wire with the platen when the print head is driven is first shielded by the inner cylinder, and the hollow portion of the double structure is formed. The sound is absorbed by the air layer and is further insulated by the outer cylinder. Therefore, the noise leaking to the outside is reduced.

Further, in the case of the second and fourth structures, since the cavity is filled with the sound absorbing material, the sound absorbing effect in this portion is improved. Therefore, the noise leaking to the outside is further reduced.

[0016]

Embodiments of the present invention will be described below with reference to FIGS.

A first embodiment is shown in FIGS. 1 to 3.

FIG. 2 is a perspective view showing the appearance of a printer device using a piezoelectric print head. In the figure, 21 is a piezoelectric print head, 22 is a platen, and 23 is a guide. The piezoelectric print head 21 is mounted on a carrier that is guided by a guide 23 and movable along the platen 22, and moves together with the carrier to perform printing. The appearance of the piezoelectric print head 21 is shown in FIG.
As shown in FIG. 4, 24 is a heat sink which is a heat dissipation member.

FIG. 1 is a side view showing the structure of the piezoelectric print head 21. Inside the heat sink 24, a piezoelectric actuator assembly 3 similar to the conventional one is provided. The heat sink 24 has a double structure in which a hollow portion 27 is formed between an inner cylinder 25 and an outer cylinder 26. This heat sink 24
The noise reduction effect due to is as follows.

The noise generated when the wire 9 collides with the platen when the print head is driven is not only shielded by the inner cylinder 25 and the outer cylinder 26 of the heat sink 24, but also attenuated by the air layer of the cavity 27. To be done. Therefore, the noise leaking to the outside is reduced, and the noise reduction of the impact printer device equipped with this print head can be realized.

FIG. 4 shows a second embodiment.

FIG. 4 is a side view showing the structure of the piezoelectric print head 31 of this example, and the same members as those in the previous example are designated by the same reference numerals. This piezoelectric print head 31 is different from the conventional one in that the hollow portions in the inner cylinder 25 and the outer cylinder 26 are filled with a sound absorbing material 32 such as a foaming sound absorbing material or a gel silicone material. In the case of this example, since the sound absorbing effect of the sound absorbing material 32 in the cavity is added, the noise leaking to the outside is further reduced. That is, the superior effect can be obtained by the preceding example.

FIG. 5 shows a third embodiment.

FIG. 5 is a side view showing the structure of the print head 41 of this example. The print head 41 has a plurality of electromagnet mechanisms 42 arranged at a predetermined pitch in the circumferential direction and corresponds to each electromagnet mechanism 42. An actuator assembly 44 including an armature 43 is mounted inside a heat sink 45. The electromagnet mechanism 42 includes a core 47 around which a coil 46 is wound, a base 48 that fixes the base of the core 47, a permanent magnet 49, and a leaf spring 50 in the illustrated arrangement.

The amateur 43 comprises a base 51 and a base 5
The beam 52 is connected to the beam 1, and the wire 53 is fixed to the tip of the beam 52. The base 51 faces the core 47. The heat sink 45 includes an inner cylinder 54 and an outer cylinder 5.
5 has a double structure in which a cavity 56 is formed. Printing by the print head 41 having such a configuration is performed as follows.

During non-printing, the coil 46 is not energized, and the armature base 51 is attracted to the core 47 against the biasing force of the leaf spring 50 by the attraction force of the magnetic flux formed by the permanent magnet 49. . Upon printing, the coil 46 is energized for a predetermined time through the connector 57 and the printed board 58. As a result, a part of the magnetic flux generated by the permanent magnet 49 is canceled by the reverse magnetic flux generated by the coil energization, the armature 43 is released from the attraction, and is rotated in the direction of arrow C by the biasing force of the leaf spring 50. The wire 53 is caused to perform a printing operation.

At the time of completion of printing, the energization of the coil 46 is stopped, and the armature 43, which has completed printing, is attracted to the core 47 again.

In the print head 41 having such a structure and operation, since the heat sink 45 has the double structure as described above, the same noise reduction effect as in the case of the first embodiment can be obtained. can get.

FIG. 6 shows a fourth embodiment.

FIG. 6 is a side view showing the structure of the print head 61 of this embodiment. The same members as those in the third embodiment are designated by the same reference numerals. In this print head 61, the inner cylinder 54 and the outer cylinder 55
The cavity is filled with the same sound absorbing material 62 as in the second embodiment. Therefore, the same effect as in the case of the second embodiment can be obtained.

[0031]

As described above, according to the present invention, since the heat sink has the double structure, the noise generated when the print head is driven is shielded by the inner and outer cylinders and absorbed by the cavity. To be done. Therefore, the noise leaking to the outside can be reduced. Further, when the hollow portion is filled with the sound absorbing material, a sound absorbing effect is added in this portion, so that the noise reducing effect is further improved.

[Brief description of drawings]

FIG. 1 is a side view showing the structure of a piezoelectric print head according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing an external appearance of a printer device using the piezoelectric print head according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing the external appearance of the piezoelectric print head according to the first embodiment of the present invention.

FIG. 4 is a side view showing the structure of the piezoelectric print head according to the second embodiment of the present invention.

FIG. 5 is a side view showing the structure of the print head according to the third embodiment of the present invention.

FIG. 6 is a side view showing the structure of the print head according to the fourth embodiment of the present invention.

FIG. 7 is a side view showing the structure of a conventional piezoelectric print head.

[Explanation of symbols]

 3 Piezoelectric Actuator Assembly 4 Base 5 Piezoelectric Element 6 Armature 7 Enlargement Mechanism 9,53 Wire 21,31 Piezoelectric Print Head 24 Heat Sink 25,54 Inner Cylinder 26,55 Outer Cylinder 27,56 Cavity 32,62 Sound Absorbing Material 41, 61 print head 42 electromagnet mechanism 43 armature 44 actuator assembly 45 heat sink

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 29/08 Z 8804-2C 8603-2C B41J 3/10 113 A

Claims (4)

[Claims] 1. A plurality of piezoelectric elements (5) and a plurality of armatures (6) provided corresponding to the respective piezoelectric elements (5) and provided with wires (9) are provided, and a voltage is applied. In a print head, a piezoelectric actuator assembly (3) for enlarging the displacement of the piezoelectric element (5) and transmitting it to the wire (9) for printing is fixed in a heat sink (24). (24) is the inner cylinder (25) and the outer cylinder (2
A printhead having a double structure in which a cavity (27) is formed between 6). 2. The print head according to claim 1, further comprising a sound absorbing material (32) filled in the cavity (27). 3. An electromagnet mechanism comprising a plurality of electromagnet mechanisms (42) and a plurality of armatures (43) provided facing the respective electromagnet mechanisms (42) and having wires (53). The amateur (4
The actuator assembly (44) for printing on the wire (53) by the rotating operation of (3) is attached to the heat sink (4).
5) In the print head fixed inside, the heat sink (45) includes an inner cylinder (54) and an outer cylinder (5).
A printhead having a double structure in which a cavity (56) is formed between 5). 4. The print head according to claim 3, further comprising a sound absorbing material (62) filled in the cavity (56).