JP2716367B2 - Print head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print head used for a dot impact type printer, and more particularly to a spring charge type print head.

[0002]

2. Description of the Related Art FIG. 2 is a front view showing an example of a conventional print head.

As shown in FIG. 2, a conventional spring-charge type print head used in a dot impact type printer has a leaf spring 15 having a print pin 16 attached to a tip end thereof.
And a permanent magnet 13 that generates a magnetic force to attract the leaf spring 15
If, provided plate springs between the plate spring 15 and the permanent magnet 13
15 , a first magnetic body 11 that attracts and bends the leaf spring 15 in a non-operating state, and a leaf spring 11 mounted on a surface of the permanent magnet 13 opposite to the surface on which the magnetic body 11 is mounted,
The second passage magnetized member 12 for mounting the rear end portion, splicing the electromagnetic coil 14 wound around the upper portion of the magnetized body 11 is mounted on the leaf spring 15 on the joint magnetized member 12 of the mounting portion and the printing pin 16 Between
And when the leaf spring 15 is operated, the opposite side beyond the linear state
And an auxiliary magnetic resonating body 17 having a predetermined gap between it and the bent leaf spring 15.

In the print head configured as described above, in a normal state, the leaf spring 15 is attracted to the upper surface of the magnetic repulsive body 11 by the magnetic force of the permanent magnet 13 and is bent. Then, a current is caused to flow through the electromagnetic coil 1414 to generate a magnetic flux in the opposite direction to the magnetic flux generated by the permanent magnet 13, and the magnetic flux generated by the permanent magnet 13 is canceled to drive the leaf spring 15 by its bending force .
Further, the print paper is bent to the opposite side, and printing is performed by hitting the printing paper with the printing pins 16 via the ink ribbon.

In the print head as described above, it is necessary to dispose the print head at a high density in order to improve the printing speed. In this case, the cross-sectional area of the leaf spring cannot be increased. In addition, saturation of magnetic flux occurs in the leaf spring, and the attraction force by the permanent magnet decreases. The auxiliary magnetic body is provided to avoid such a decrease in the attraction force.

[0006]

In the conventional print head as described above, the auxiliary magnetic reversal member is formed of a plate-like component.
Slightly since the leaf spring flexed when the leaf spring is operated and the auxiliary relay magnetized body to avoid the contact, between the upper surface of the lower surface and the leaf spring of the auxiliary relay magnetized member, the amount of deflection of the leaf spring It is necessary to provide a gap (reference numeral H in FIG. 2) corresponding to the larger amount . For this reason, the function as an auxiliary magnetic path cannot be sufficiently exhibited by the auxiliary magnetic body, and therefore, there is a problem that the print head becomes large and expensive, and the power consumption also increases. .

[0007]

According to the present invention, there is provided a print head comprising:
A leaf spring having a print pin attached to a tip thereof, a permanent magnet for generating a magnetic force for attracting the leaf spring, and the leaf spring provided between the leaf spring and the permanent magnet when the leaf spring is in an inoperative state. And a second magnetic body mounted on the surface of the permanent magnet opposite to the surface on which the first magnetic body is mounted, and mounted with the leaf spring on the upper surface. And when the leaf spring operates between the printing pin and the mounting portion mounted on the leaf spring on the second magnetic pole and the electromagnetic coil wound around the upper part of the first magnetic pole. An auxiliary magnetic resonator having a predetermined gap between the leaf spring and a leaf spring bent to the opposite side beyond the linear state, wherein the leaf spring between the printing pin of the auxiliary magnetic respirator and a mounting portion is provided. The shape of the surface facing the Shape before <br/> SL leaf spring when deflected to the maximum after the operation Te and is obtained by forming to be substantially parallel, in particular, the auxiliary splicing magnetized member, stacking a plurality of thin plates, A line connecting the tip portions of the plurality of thin plates on the side facing the leaf spring is substantially parallel to the shape of the leaf spring when the permanent magnet is bent to the maximum after being operated with the attraction released. Or formed from one block, and the shape of the surface facing the leaf spring is changed after the operation by releasing the attraction by the permanent magnet.
The leaf spring is formed so as to be substantially parallel to the shape of the leaf spring when largely bent.

[0008]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front view showing an embodiment of the present invention.

In FIG. 1, a lower end of a first magnetic pole 1 is screwed to a second magnetic pole 2 with a permanent magnet 3 interposed therebetween. The leaf spring 5 has a rear end mounted on the upper surface of the magnetic resilient body 2, a front end thereof facing the magnetic resilient body 1, and a print pin 6 fixed to the upper surface. An electromagnetic coil 4 is wound around the upper part of the magnetic resonating body 1. When a current flows through the electromagnetic coil 4, a magnetic flux in the opposite direction to the magnetic flux generated by the permanent magnet 3 is generated. On the rear end of the leaf spring 5, an auxiliary magnetic body 7 is mounted.
Are screw-fixed to the magnetic body 2.

In a normal state, the leaf spring 5 is attracted to the upper surface of the magnetically permeable body 1 by the magnetic force of the permanent magnet 3 and is flexed. A magnetic flux in the opposite direction to the magnetic flux generated by the magnet 3 is generated, the attractive force generated by the permanent magnet 3 is canceled, the leaf spring 5 is driven by the bending force, and the print pin 6 hits the printing paper via the ink ribbon.

In the auxiliary magnetic body 7, a plurality of thin plates having different lengths are stacked in order of shorter length with their rear ends aligned. A line connecting the leading end portions of the plurality of thin plates is a permanent magnet. When the maximum bending after the suction by 3 was released and operated
Is formed so as to be substantially parallel to the shape of the leaf spring 5 (reference numeral 5a). Thus the leaf spring 5, when the operation is opened to suction by the permanent magnet 3, flexed to the maximum on the opposite side beyond the straight state a state of reference numeral 5a, a envelope surface of the opposite side of the auxiliary passage magnetized member 7 Be almost parallel. However, when the leaf spring 5 is flexed to a maximum after operating, the leaf spring 5
A suitable gap is provided between the leaf spring 5 and the auxiliary magnetic body 7 so that none of the above-mentioned parts contact the auxiliary magnetic body 7.

With the above-described structure, the amount of the gap between the leaf spring 5 and the auxiliary magnetic body 7 can be minimized. Therefore, it is possible to prevent the attraction force of the permanent magnet 3 from decreasing. Becomes

[0014] The auxiliary magnetic body may be formed by cutting one block instead of stacking a plurality of thin plates.

[0015]

As described above, in the print head of the present invention, the shape of the lower surface of the front end portion of the auxiliary magnetic body is formed so as to be substantially parallel to the shape when the leaf spring operates. Since the amount of the gap between the leaf spring and the auxiliary magnetic body can be minimized, there is an effect that it is possible to prevent a decrease in the attraction force due to the permanent magnet, and therefore, the print head can be reduced in size and cost. And power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing one embodiment of the present invention.

FIG. 2 is a front view showing an example of a conventional print head.

[Explanation of symbols]

 1 ・ 2 ・ 11 ・ 12 Magnet 3.13 Permanent magnet 4.14 Electromagnetic coil 5.15 Leaf spring 6.16 Printing pin 7.17 Auxiliary magnet

Claims (3)

(57) [Claims] A leaf spring having a print pin attached to a tip end thereof;
A permanent magnet that generates a magnetic force that attracts the leaf spring, and a first magnetic body that is provided between the leaf spring and the permanent magnet and that attracts and bends the leaf spring when the leaf spring is in an inoperative state. A second magnetic pole mounted on the upper surface of the permanent magnet opposite to the surface on which the first magnetic pole is mounted, and having the leaf spring mounted on the upper surface thereof, and wound around an upper portion of the first magnetic pole. The electromagnetic coil and the plate which is mounted on the plate spring on the second magnetic pole and which is bent to the opposite side beyond the linear state when the plate spring operates between the printing pin and the mounting portion. In a print head comprising an auxiliary magnetic body having a predetermined gap between the spring and a spring, the shape of the surface of the auxiliary magnetic body facing the leaf spring between the print pin and the mounting portion is attracted by the permanent magnet. It said plate when flexed to the maximum after the operation is opened Print head is characterized in that was formed to have a substantially parallel to the root of shape. 2. A method in which a plurality of thin plates are stacked, and a line connecting the tip portions of the plurality of thin plates on the side facing the leaf spring is operated by releasing the attraction by the permanent magnet .
2. The print head according to claim 1, further comprising: the auxiliary magnetic resilient member formed so as to be substantially parallel to the shape of the leaf spring when it is flexed to a maximum rearward. 3. The shape of the surface formed of one block and facing the leaf spring is the same as the shape of the leaf spring when it is bent to the maximum after the permanent magnet has been released and operated. 2. The print head according to claim 1, further comprising the auxiliary magnetic body formed so as to be substantially parallel.