JPH0781097A - Printing head for wire dot printer - Google Patents

Abstract

PURPOSE:To execute a substantial coincidence of vibration performances of all movable sections by executing a minute adjustment of a mechanical performance of the movable sections after having once assembled a piezoelectric driving type or an electromagnetic driving type actuator. CONSTITUTION:A plurality of actuators, and movable sections 54, 56 and 52 assembled in each one of the actuators comprise a wire dot printer printing head and minute adjustment means 60, 62 for executing a minute adjustment of a mechanical performance of the movable sections itself in order that each actuator gives a desired vibration performance to the movable sections in a wire dot printer printing head wherein the movable sections include elastic supporting means 54a, 56a and 52a and a printing wire element supported by the means are equipped.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to printheads for wire dot printers.

[0002]

BACKGROUND OF THE INVENTION As is well known, wire dot printers are typical of impact printers, the print head of which comprises a number of print wire elements, each print wire element being incorporated into an individual actuator. For example, 24 ×
When recording characters and symbols as a 24 matrix dot image, the print head is provided with 24 print wire elements and 24 actuators for driving each of these print wire elements. By selectively driving based on the image data, characters and symbols are recorded as a 24 × 24 matrix dot image.

Piezoelectric drive actuators and electromagnetic drive actuators are known as actuators for driving print wire elements. In either actuator, each print wire element is resiliently supported by leaf spring means and is driven from the non-print position to the print position with a stroke of about 280 to about 300 μm when the actuator is electrically energized. At this time, the tip of the print wire element has an impact on a recording medium such as a recording paper via an ink ribbon, and dot recording is performed on the recording medium. In order to obtain good print quality, the impact amount of all print wire elements must be uniform, however, in reality, the impact amount of each print wire element is different, and therefore good print quality is obtained. Cannot be guaranteed.

[0004]

The difference in the impact amount of each print wire element as described above results from the fact that the mechanical characteristics of the movable portion of each actuator are not uniform. More specifically, when the individual actuators are taken out from the print head and the vibration characteristics of the movable parts immediately after the actuators are electrically biased are examined and seen, it is understood that the vibration characteristics of the individual movable parts are different from each other. Needless to say, the various movable components that make up the individual actuators are given a certain degree of accuracy, and a certain standard is also maintained for their assembly accuracy. However, the mechanical characteristics of the moving parts of the individual actuators are Cannot be made uniform so that the vibration characteristics of all the movable parts substantially match each other. In short, conventionally, after the actuator is once assembled, the mechanical characteristics of the movable portion are not finely adjusted to match the vibration characteristics of all the print wire elements. Therefore, an object of the present invention is to provide a print head for a wire dot printer,
After assembling the actuator once, the mechanical characteristics of the movable part are finely adjusted to substantially match the vibration characteristics of all the movable parts.

[0005]

According to the present invention, there is provided a print head for a wire dot printer comprising a plurality of actuators and movable parts incorporated in the respective actuators, the movable parts being elastic supporting means. In a print head for a wire dot printer including a print wire element supported by the elastic support means, each actuator finely adjusts the mechanical characteristic of the movable portion itself so as to give a desired vibration characteristic to the movable portion. It is characterized in that it is provided with a fine adjustment means for performing.

[0006]

As is apparent from the above description, in the print head for a wire dot printer according to the present invention, each actuator adjusts the mechanical characteristics of the movable part itself so as to impart a desired vibration characteristic to the movable part. Since the fine adjustment means for adjusting is provided, it is possible to substantially match the vibration characteristics of all the movable parts with each other after assembling the individual actuators.

[0007]

Various embodiments of the print head for a wire dot printer according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a perspective view of the appearance of a printhead in which the present invention can be implemented, the printhead being an annular housing 1 formed from a suitable metal material, such as steel.
The outer peripheral wall of the annular housing 10 is provided with a large number of radiating fins 12 that integrally project in the radial direction from the outer peripheral wall. As shown in FIG. 2, the inner flange 14 extends from the inner edge of the front annular end of the annular housing 10.
Are integrally projected, and a disc-shaped disc 16 is fixed to the inner flange 14 by a set screw. A nose-shaped member 18 is integrally formed on the disk-shaped disc 16, and the top surface of the nose-shaped member 18 serves as a printing surface 20. The printed circuit board 22 is fixed to the other annular end portion of the annular housing 24, and a suitable rubber sheet 24 is interposed therebetween as shown in FIG.

The print head includes, for example, 24 piezoelectric drive type actuators 26. These piezoelectric drive type actuators 26 are housed in an annular housing 24 and are arranged in an annular shape at substantially equal intervals along the inner wall surface thereof. It
As shown in detail in FIG. 3, each piezoelectric drive type actuator 26 is composed of a piezoelectric element laminated body 28, and the piezoelectric element laminated body 28 is formed of a large number of piezoelectric elements integrally held by a tie band 30. . The piezoelectric element laminate 28 is disposed adjacent to the support block member 32, and is partially supported by the support block member 32. More specifically, the protruding portion 3 is provided on the rear end side of the support block member 32.
4 is formed, and the rear end of the piezoelectric element laminate 28 is fixed to one end of a screw 36 screwed to the projecting portion 34 of the support block member 32. A block piece 38 is fixed to the front end of the piezoelectric element laminate 28, and the block piece 38 is arranged near the front end edge of the support block member 32. The support block member 32 is fixedly supported by the inner flange 14 of the annular housing 10 via a ring member 40 as shown in FIG.

A connector 42 is attached to the projecting portion 34 of the support block member 32, and the connector 42 has a pair of connecting pins 44 inserted into the printed circuit board 22 as shown in FIG. The pair of connecting pins 44 are electrically connected to the positive and negative electrode terminals of the piezoelectric element laminate 28 via the pair of lead wires 46. Further, as is apparent from FIGS. 1 and 2, the printed circuit board 22 has a multi-connector 48.
The multi-connector 48 is provided with a large number of connecting pins 50. A number of connecting pins 50 of the multi-connector 48 are electrically connected to a control circuit board (not shown) of the wire dot printer via a flexible flat cable (not shown). Of course, the multi-connector 48
Each of the connecting pins 50 is connected to the connecting pin 44 of the 24 connectors 42 through the circuit pattern formed on the printed circuit board 22, whereby the 24 piezoelectric element laminates 2 are connected.
A drive voltage is selectively applied to the drive circuit 8 from a drive power supply circuit provided on the control circuit board of the printer.

As best shown in FIG. 3, the piezoelectrically actuated actuator 26 further comprises an arm lever 52, the outer end of which is two parallel leaf spring elements 54 and 56 secured thereto. Is supported by the support block member 44 and the piezoelectric element laminate 40. More specifically, both ends of the outer leaf spring element 54 are fixed to the outer end portion of the arm lever 52 and the front end edge of the support block member 32, respectively, and the inner leaf spring element 54 also.
Both ends of are fixed to the outer end of the arm lever 52 and the block piece 38 of the piezoelectric element laminate 28. At the inner end of the arm lever 52, as shown in FIG.
8 is fixed, the print wire element 58 extending through the disc-shaped disc 16 and the nose-shaped member 18 as shown in FIG. 2, at which time the free end 58a of the print wire element 58.
Is projected from the printing surface 20 of the nose-shaped member 18.

When a drive voltage is applied to increase the height or length of the piezoelectric element laminate 28, the arm lever 52 causes the arm lever 52 to center around the midpoint of the span length of the outer leaf spring element 54, as shown by the arrow in FIG. It is rotated in the direction of A, which drives the print wire element 58 forward toward the print position for dot recording. When the application of the drive voltage to the piezoelectric element stack 28 is finished, the printing wire element 58 is returned to the non-printing position, that is, the initial position shown in FIG. 3, due to the elastic force of the parallel leaf spring elements 54 and 56. According to such a configuration of the piezoelectric drive type actuator 26, even if the height, that is, the increment of the length due to the application of the drive voltage to the piezoelectric element laminated body 28 is as small as about 14 to 15 μm, The increment is amplified by the arm lever 52 so that the print wire element 58 can be driven from the non-print position to the print position with the stroke of about 280 to about 300 μm required for dot recording.

As is apparent from FIG. 1, the free ends 58a of the 24 print wire elements 58 are arranged in parallel in two rows at a predetermined pitch on the print surface 20 of the nose-shaped member 18, at this time. The free ends 58a included in one row are offset by half the pitch with respect to the free ends 58a included in the other row, and the half pitch is a dot when a character or symbol is recorded as a dot image by the print head shown in the figure. It corresponds to the pitch.

In order to construct the print head as shown in FIGS. 1 and 2, it is necessary to prepare 24 piezoelectric actuators as described above.
It is preferable that the moving parts of all 24 piezoelectric drive actuators have the same mechanical characteristics, but in reality, the moving parts of all 24 piezoelectric drive actuators have different mechanical characteristics. Therefore, the vibration characteristics of the movable part when a drive voltage is applied to each piezoelectric drive type actuator also differ. For example, one of the 24 piezoelectric drive type actuators is taken out and supported by an appropriate support, and then a drive voltage as shown in the graph of FIG. 4A is applied to the piezoelectric drive type actuator. When the displacement of the tip of the print wire element is observed, the tip of the print wire element first vibrates greatly immediately after the application of the driving voltage, and then the vibration gradually attenuates. Such a vibration characteristic is, for example, as shown by the dotted line in the graph of FIG. 4B, and this vibration characteristic is different from the desired vibration characteristic shown by the solid line in the graph of FIG. 4B, for example. This is also true for other piezoelectric drive actuators, and even if some of the movable parts have the same vibration characteristics, the probability is extremely small and accidental. Further, even if the vibration characteristics of all the movable parts can be made to coincide by greatly improving the accuracy of the movable components of the piezoelectric actuator and the assembly accuracy thereof, the cost for that is enormous and the practical It is practically impossible. However, according to the present invention, each piezoelectric drive type actuator is provided with fine adjustment means for finely adjusting its mechanical characteristics, so that after the piezoelectric drive type actuator is assembled, the mechanical adjustment is performed by the fine adjustment means. Various properties can be adjusted to give the print wire element the desired vibration characteristics.

In the embodiment shown in FIG. 5, such fine adjustment means is a leaf spring element 56 fixed to the arm lever 52.
And a pair of piezoelectric elements 60 and 62 incorporated on one end 56a side. As is apparent from FIGS. 5 and 6, one end 56a of the leaf spring element 56 is an enlarged end, and the enlarged end 56a is formed with a groove 64 for receiving and fixing the arm lever 52. On the other hand, as is clear from FIGS. 5, 7 and 8, groove portions 66 and 68 for receiving and fixing the piezoelectric elements 60 and 62 are formed in the arm lever 52 before and after the enlarged end portion 56a. The one end portion 54a of the leaf spring 54 is also an enlarged end portion, and the enlarged end portion 54a is also formed with a groove portion for receiving and fixing the arm lever 52. A pair of electrodes (not shown) is applied to each of the piezoelectric elements 60 and 62, and when a voltage is applied to each pair of electrodes, each piezoelectric element 60, 62 changes its thickness in the direction indicated by arrow B. To be done. For example, when a voltage is applied to increase the thickness of the piezoelectric element 60 and a voltage is applied to decrease the thickness of the piezoelectric element 62, the plate span element 5
The distance between the ends 54a and 56a of 4 and 56 is widened, on the contrary, to apply a voltage to reduce the thickness of the piezoelectric element 60 and to increase the thickness of the piezoelectric element 62. When a voltage is applied, it is a flat plate element 5
The distance between the ends 54a and 56a of 4 and 56 is reduced.

Since the vibration characteristic of the movable portion of each actuator 26 largely depends on the distance between the pair of leaf spring elements 54 and 56, the applied voltage to the piezoelectric elements 60 and 62 is appropriately adjusted after the piezoelectric drive actuator 26 is assembled. Both ends 54a and 56 of the leaf spring elements 54 and 56.
It is possible to give desired vibration characteristics to the movable portion by finely adjusting the distance between a. For example, in FIG. 4B, it is possible to match the vibration characteristic indicated by the dotted line with the vibration characteristic indicated by the solid line by appropriately adjusting the applied voltage to the piezoelectric elements 60 and 62. The voltage applied to the piezoelectric elements 60 and 62 when a desired vibration characteristic is given to the movable portion is stored as data. After such data of the applied voltage is obtained for all of the 24 piezoelectric drive type actuators 26, the piezoelectric drive type actuators 26
Embedded in the annular housing 10.

A drive power supply circuit 70 as shown in FIG. 9 is provided on the control circuit board of the wire dot printer on which the print head thus obtained is mounted, and the drive power supply circuit 70 is provided during the printing operation of the wire dot printer. From 70, the piezoelectric elements 60 and 6 of the 24 piezoelectric actuators 26
A drive voltage based on the above data is applied to each of the two. Thus, it is possible to impart substantially the same vibration characteristics to all 24 moving parts contained in the print head during operation of the wire dot printer.

In the embodiment described above, the end portion 56a is displaced with respect to the end portion 54a in order to adjust the distance between the both end portions 54a and 56a of the leaf spring elements 54 and 56. The end 54a may be displaced with respect to the portion 56a, or both ends may be displaced by interposing the end 56a and the end 54a between three piezoelectric elements. Further, the support block member 52 and the block piece 3 are provided with a piezoelectric element on either or both of the opposite ends of the leaf spring elements 54 and 56.
Alternatively, the distance between the ends may be finely adjusted.

In the embodiment shown in FIGS. 10 and 11, the fine adjustment means described above is formed on the arm lever 52 between the ends 54a and 56a of the leaf spring elements 54 and 56 fixed to the arm lever 52. 12 is formed by applying a wedge tool 74 as shown in FIG. 12 to the wedge tool receiving hole 72.
The distance between 6a is finely adjusted. More specifically, first, for example, a suitable anvil (not shown) is prepared, and the anvil is formed with a groove adapted to receive a tip of a wedge tool. Next, the arm lever 52 is placed on the anvil, with the wedge tool receiving hole 70 straddling the anvil at this time. Then, the tip of the wedge tool 72 is accommodated in the wedge tool receiving hole 70, and the wedge tool is hit with a hammer or the like to plastically deform the wedge tool receiving hole 74. For example, as shown in FIG. 13, the wedge tool receiving holes 74 have leaf spring elements 54 and 56.
When the wedge tool 72 is suitable for the wedge tool receiving hole 74 so as to be plastically deformed in the direction (arrow C) perpendicular to the direction,
Since the wedge tool receiving hole 74 is deformed as an ellipse having a major axis in the direction indicated by arrow C, the distance between the ends 54a and 56a of the leaf spring elements 54 and 56 is widened. In addition, as shown in FIG. 14, the wedge tool receiving hole 74 has the leaf spring element 54.
When the wedge tool 72 is suitable for the wedge tool receiving hole 74 so as to be plastically deformed in a direction (arrow D) parallel to and 56, the wedge tool receiving hole 74 has a long axis in the direction indicated by the arrow D. Since it is deformed as an ellipse with a radius of 50, the distance between the ends 54a and 56a of the leaf spring elements 54 and 56 is reduced. Therefore, as in the case of the above-described embodiment, it is possible to give desired vibration characteristics to the movable portion by finely adjusting the distance between the both end portions 54a and 56a of the leaf spring elements 54 and 56. In the embodiment shown in FIGS. 10 and 11, the fine adjustment of the distance between the both end portions 54a and 56a of the leaf spring elements 54 and 56 is carried out by striking the wedge tool 74 with a hammer or the like. The adjustment work involves trial and error, but compared to the above-described embodiment, parts such as piezoelectric elements are not required, and further, an additional drive power supply circuit is not required for the control circuit board of the wire dot printer. It should be noted.

FIG. 15 illustrates another type of printhead embodying the present invention, which printhead also comprises an annular housing 76 formed of a suitable metal material, such as steel. A nose-shaped member 80 is provided on a front end wall 78 of the annular housing 76, and a printed circuit board 84 is attached to a rear opening end surface of the annular housing 76 via a suitable rubber sheet 82. The ring-shaped permanent magnet 8 is provided in the annular housing 76.
6 is provided, and the ring-shaped permanent magnet 86 is fixed to the front end wall 78 of the annular housing 76. An annular block member 88 is fixed to the ring-shaped permanent magnet 86, and the annular block member 88 is made of a suitable magnetic material. Twenty-four electromagnetically driven actuators 90 are provided in an inner space formed by the ring-shaped permanent magnet 86 and the annular block member 88, and these electromagnetically driven actuators 90 are substantially equal along the inner wall surface of the annular block member 88. It is arranged at intervals. Each electromagnetic drive type actuator 90 comprises a core 90a fixed on the inner flange portion 88a of the annular block member 88, and a solenoid 90b surrounding the core 90a. The solenoid 90b has a circuit pattern formed on the printed circuit board 84. To the multi-connector 92. The multi-connector 92 is mounted on the printed circuit board 84, and the multi-connector 92 is provided with a large number of connecting pins 94. Multi connector 92
A plurality of connecting pins 94 are electrically connected to a control circuit board (not shown) of the wire dot printer via a flexible flat cable (not shown), and 24 solenoids 90b are provided on the control circuit board of the printer. Is selectively energized by the drive power supply circuit.

Further, each electromagnetically driven actuator 90 comprises an armature 90c, which is supported by a leaf spring element 96 protruding in a cantilever manner from a ring-shaped permanent magnet. An arm element 98 is attached to each armature 90c.
Extend toward the center of the annular housing 76. A print wire element 100 is attached to an inner end of each arm element 98, and a free end 100 a of the print wire element 100 is exposed to the outside from a nose-shaped member 80. In detail,
As shown in FIG. 15, the nose-shaped member 80 is formed with an insertion passage 102 for the print wire element 100, in which the guide plate element 104 and the end face element 106 are formed.
And each print wire element 100 has a guide plate element 10
4 and the end surface element 106 are penetrated, and the free end 100 a thereof is projected from the end surface element 106. End face element 1
06 provides a print surface, and the free ends 100a of the 24 print wire elements 100 are arranged in a manner similar to the free ends 58a of the print wire elements shown in FIG.

When the solenoid 90b of each electromagnetically actuated actuator 90 is not electrically energized, its core 90a, together with the ring-shaped permanent magnet 86 and the annular block member 88, forms a closed magnetic circuit, and thus the armature 90c. The core 90a resists the elastic force of the leaf spring element 96.
The print wire element 100 is in the non-printing position. When the solenoid 90b is electrically biased to eliminate the closed magnetic circuit described above, the armature 90c is immediately disengaged from the core 90a by the elastic force of the leaf spring element 96, and the print wire element 10 is removed.
0 is driven from the non-printing position toward the printing position (FIG. 15) to perform dot recording.

Even in the case of the print head shown in FIG. 15, the mechanical characteristics of the individual electromagnetically driven actuators 90 are different for the same reason as in the above-described embodiment, and therefore, the individual movable parts are different. Vibration characteristics are also different. The vibration characteristics of the print wire element 100 are primarily dependent on the flex span length of the leaf spring element 96. Therefore, by finely adjusting the bending span length of the leaf spring element 96, it is possible to give desired vibration characteristics to the movable portion.

In the embodiment shown in FIG. 15, the piezoelectric element 108 is incorporated in the fixed support portion of the leaf spring element 96 as fine adjustment means for finely adjusting the bending span length of the leaf spring element 96. As shown in detail in FIG. 16, the leaf spring element 96 is fixed in such a manner that the piezoelectric element 108 is embedded in a position fixed by the ring-shaped permanent magnet 86, and each piezoelectric element 108 has a pair of electrodes (not shown). Is applied and a voltage is applied to the pair of electrodes, the piezoelectric element 10
8 has its thickness varied in the radial direction of the annular housing 76. For example, when a voltage is applied to increase the thickness of the piezoelectric element 108, the leaf spring element 96
Of the leaf spring element 96 increases when a voltage is applied to reduce the thickness of the piezoelectric element 108. Therefore, it is possible to give desired vibration characteristics to the movable portion by finely adjusting the bending span length of the leaf spring element 96 by appropriately adjusting the voltage applied to the piezoelectric element 108 after the electromagnetically driven actuator 90 is assembled. Thus, the vibration characteristics of the movable parts of all 24 electromagnetic actuators 90 can be made substantially the same.

Similarly to the case described above, after the applied voltages to the 24 piezoelectric elements 108 are stored as data,
A plurality of piezoelectric drive type actuators 90 in the annular housing 7
Installed in 6. The control circuit board of the wire dot printer equipped with the print head thus obtained is
7, a driving power supply circuit 110 as shown in FIG.
A driving voltage based on the above-mentioned data is applied to each of 08. Thus, it is possible to impart substantially the same vibration characteristics to all 24 movable parts included in the print head during operation of the wire dot printer.

[0025]

As is apparent from the above description, according to the present invention, it is possible to make the vibration characteristics of a large number of movable parts included in a print head for a wire dot printer all the same, so that the printing quality is improved. It is possible to improve.

[Brief description of drawings]

FIG. 1 is a perspective view of a print head for a wire dot printer in which the present invention can be implemented.

FIG. 2 is a vertical cross-sectional view of the print head for the wire dot printer of FIG.

FIG. 3 is an enlarged elevational view of a piezoelectric drive type actuator incorporated in the print head for the wire dot printer of FIG.

4A is a graph showing a characteristic of a voltage applied to the piezoelectric drive type actuator of FIG. 3, and FIG. 4B is a graph showing a vibration characteristic of a movable part driven by the piezoelectric drive type actuator.

5 is a partially enlarged view showing a part of the piezoelectric drive type actuator of FIG. 3 in an enlarged manner. FIG.

6 is a sectional view taken along line VI-VI in FIG.

7 is a cross-sectional view taken along the line VII-VII of FIG.

8 is a cross-sectional view taken along the line VIII-VIII in FIG.

9 is a block diagram for applying a drive voltage to a piezoelectric element incorporated therein in order to finely adjust the mechanical characteristics of the piezoelectric drive type actuator of FIG.

FIG. 10 is a partially enlarged view corresponding to FIG. 5, showing another embodiment of the present invention.

11 is a sectional view taken along line XI-XI in FIG.

12A is an end view of the wedge tool used in the embodiment of FIG. 10, and FIG. 12B is a partial side view thereof.

13 is an explanatory diagram illustrating a usage mode of the wedge tool of FIG. 12 in the embodiment of FIG.

FIG. 14 is an explanatory view explaining another usage mode of the wedge tool of FIG. 12 in the embodiment of FIG. 10.

FIG. 15 is a vertical sectional view of another type of print head for a wire dot printer embodying the present invention.

16 is a partially enlarged view showing an enlarged main part of the print head for the wire dot printer of FIG.

17 is a block diagram for applying a drive voltage to a piezoelectric element incorporated therein for finely adjusting the mechanical characteristics of the piezoelectric drive type actuator of FIG. 15. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Annular housing 18 ... Nose-shaped member 20 ... Printing surface 22 ... Printed circuit board 26 ... Piezoelectric drive type actuator 28 ... Piezoelectric element laminated body 30 ... Tie band 32 ... Support block member 36 ... Screw 38 ... Block piece 40 ... Ring member 42 ... Connector 44 ... Connecting pin 46 ... Lead wire 48 ... Multi-connector 50 ... Connecting pin 52 ... Arm lever 54/56 ... Leaf spring element 58 ... Printing wire element 60/62 ... Piezoelectric element 64 ... Groove 66/68 ... Groove 70 Drive power circuit 72 ... Wedge tool receiving hole 74 ... Wedge tool 76 ... Annular housing 80 ... Nose-shaped member 84 ... Printed circuit board 86 ... Ring-shaped permanent magnet 88 ... Annular block member 90 ... Electromagnetic drive actuator 90a ... Core 90b ... Solenoid 90c ... Armature 92 ... Multi-connector 94 ... Connecting pin 6 ... leaf spring elements 98 ... arm elements 100 ... printing wire elements 102 ... insertion path 104 ... guide plate elements 106 ... end surface elements 108 ... piezoelectric elements 110 ... drive power supply circuit

Front page continuation (72) Inventor Masakichi Kageyama 1405 Daimaru, Inagi-shi, Tokyo Inside Fujitsu Aisotec Co., Ltd.

Claims (4)

[Claims] 1. A plurality of actuators (26; 90)
And movable parts (54, 5) incorporated in each actuator.
6, 52, 58; 90c, 98, 96, 100), wherein the movable part has elastic supporting means (54, 56, 52; 90c,
98, 96) and a print wire element (58; 100) supported by the elastic support means, wherein each actuator (26; 90) comprises the movable part (5;
4, 56, 52, 58; 90c, 98, 96, 100).
Fine adjustment means (60, 62, 70;) for finely adjusting the mechanical characteristics of the movable part itself in order to give desired vibration characteristics to the
72; 108, 110), a print head for a wire dot printer. 2. The print head for a wire dot printer according to claim 1, wherein each of the actuators (26)
Includes a fixed support structure (32) and a piezoelectric drive means (28) arranged adjacent to the fixed support structure, the movable part protruding from the fixed support structure and the piezoelectric drive means. A pair of leaf spring elements (54, 56) and an arm lever element (52) elastically supported via the pair of leaf spring elements are included, and a print wire is provided on the free end side of the arm lever elements. The element (58) is fixedly supported, and the one end portion (56a) of the leaf spring element (56) of at least one of the pair of leaf spring elements is finely adjusted by the fine adjustment means to finely adjust the distance between the pair of leaf spring elements. A print head for a wire dot printer, which comprises piezoelectric element means (60, 62) incorporated on the side and voltage applying means (70) for applying a predetermined voltage to the piezoelectric element means. 3. The print head for a wire dot printer according to claim 1, wherein each of the actuators (26)
Includes a fixed support structure (32) and a piezoelectric drive means (28) arranged adjacent to the fixed support structure, the movable part protruding from the fixed support structure and the piezoelectric drive means. A pair of leaf spring elements (54, 56) and an arm lever element (52) elastically supported via the pair of leaf spring elements are included, and a print wire is provided on the free end side of the arm lever elements. An element (58) is fixedly supported and the fine adjustment means is formed in the arm lever element between the ends of the pair of leaf spring elements on the side of the arm lever element to finely adjust the distance between the pair of leaf spring elements. A print head for a wire dot printer, which comprises a wedge tool receiving hole (72). 4. The print head for a wire dot printer according to claim 1, wherein each of the actuators (90)
Includes an electromagnet (90a, 90b), the movable part being driven by the electromagnet (90).
c) and a leaf spring element (96) for elastically supporting the armature element in the form of a cantilever, the print wire element (100) being fixedly supported with respect to the armature element, and the fine adjustment. Means for finely adjusting the flexure span length of the leaf spring element, a piezoelectric element means (108) incorporated in a fixed support portion of the leaf spring element, and a voltage applying means for applying a predetermined voltage to the piezoelectric element means (108). 110), and a print head for a wire dot printer.