JPS61181653A - Printing head - Google Patents

Abstract

PURPOSE:To relieve the lowering of printing quality by forming at least two slits in a permanent magnet, a yoke, and a core base. CONSTITUTION:Two slits 9 are formed in a yoke 2, a permanent magnet 1, and a core base 3. The slits 9 are formed down to the bottom of the core 3a. The path of magnetic flux leaking through the core base 3, the bottom of the core 3a, the yoke 2, and the permanent magnet 1 is interrupted thereby, and impact force is raised to relieve the lowering of printing quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head of a printer used as an output device in an information processing apparatus.

[Conventional technology]

Conventionally, the print head of this woodcutter's printer, for example,
There are the ones shown in FIG. 6, FIG. 7, and FIG. 1 in the diagram
is a permanent magnet, and this permanent magnet 1 has a ferromagnetic yoke 2.
and a core base 3 are provided. The core base 3
An excitation coil 8 is provided in the core 3a that is integrally provided with the core 3a.
is installed. 4 is an armature, and this armature 4 is attracted to the yoke 2 and the core 3a, and can be operated by the repulsive force of a coil spring 70 when the coil 8 is excited.

This coil spring 7 engages with the guide hole 5 and transmits a repulsive force to the armature 4 via a cap 6 attached to the coil spring 7.

On the other hand, to explain the operation of the print head, the magnetic flux generated from the permanent magnet 1 passes through the yoke 2 and the core 3a, reaches the opposing armature 4, and rotates this armature 4 with the yoke 2 side as a fulcrum. It is attracted to the yoke 2 and the core 3a.

In this case, the amateur 4 can, via the cap 6,
The coil spring 7 is bent and is subjected to a repulsive force from the coil spring 70.

Next, the armature 4 is operated by the repulsive force of the coil spring 7 by exciting the coil 8 to provide magnetic flux in the opposite direction to the permanent magnet 1 and canceling the attractive force. Note that the amateur 4 is restored by stopping the excitation of the coil 8.

Furthermore, the core base 3, permanent magnet 1,
The structure of the yoke 2 is the same as shown in FIGS. 6, 7, and 8. The core base 3 in the figures is provided integrally with the core 3a, and the bottom surface of the core 3a is connected to the core 3a. Since it is formed on the same surface as the bottom surface of the base 3, the magnetic flux (indicated by the broken line in the figure) generated when the coil 8a is excited as shown in FIG. , the magnetic flux not only passes through the magnetic path with the attracted armature 4, but also leaks more or less to the adjacent core 3b, further adjacent core 3c, and all the cores 3a to form a magnetic path as shown in FIG. .

Therefore, for example, when the coils 8a and 8b are excited simultaneously, the magnetic flux leaked from the coil 8a enters all the cores 3a including the core 3c.

Moreover, the magnetic flux leaked from the coil 8b enters all the cores 3a including the core 3b. The direction of this leakage magnetic flux is opposite to the direction of the excited magnetic flux, and the coils 8a, 8b
When both are excited simultaneously, the magnetic flux becomes small because the incoming leakage magnetic flux acts as a minus with respect to the magnetic flux generated when each is excited individually.

In the above conventional example, 2 pieces are excited simultaneously, but when 10 or 20 pieces are excited simultaneously, there will be more interference with each other, and this will reduce the magnetic flux, reducing the single generated magnetic flux to 1. If 1O is simultaneously excited, it will decrease by 18%, and 2
If it is 0, it will decrease by 34%. This means that the impact force during printing is reduced, and printing is good when printing with one digit, but when 10 or 20 digits are simultaneously excited, the print quality deteriorates.

[Problems to be solved]

In the conventional print head described above, the core base and the bottom of the core are integrally formed, and the permanent magnet and yoke are also ring-shaped, so when each coil is energized, the energy from the coil is There was a problem in that the leakage magnetic flux easily passed through and interfered with each other, resulting in a decrease in printing quality.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a print head in which the deterioration of print quality is minimized.

[Means for solving problems]

The structure of the print head according to the present invention to achieve the above object of the present invention is that the print head is provided with a permanent magnet connected to a ferromagnetic yoke and a core base. It is formed by forming at least two slits.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

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

FIG. 2 is a plan view showing a second embodiment of the print head according to the present invention.

FIG. 3 is a plan view showing a third embodiment of the print head according to the present invention.

Figure WJ4 is a sectional view taken along the line X--X in Figure 2.

In this embodiment, parts common to those in the conventional example are denoted by the same reference numerals, and explanation thereof will be omitted.

In FIG. 1, two slits 9 are formed in the yoke 2, the permanent magnet 1, and the core base 3 between the armatures 4 and 4, and the slits 9 extend to the bottom surface of the core 3a. In Figure 2, the core base 3, permanent magnet 1, armature 4,
Although the slits 9 are formed to divide the yoke 2 between the four spaces into four, the slits 9 are not completely divided.

FIG. 4 is a cross-sectional view taken along line XX in FIG.
The structure is joined only by FIG. 3 shows an embodiment in which 24 slits 9 are provided.

By forming the slit 9 in this manner, the magnetic path of the magnetic flux leaking through the core base 3, the bottom surface of the core 3a, the yoke 2, and the permanent magnet 1 is cut off.

For example, the effect of forming two slits 9 as shown in Fig. 1 is that compared to a conventional print head without slits,
The magnetic flux usage when 20 coils are simultaneously excited is improved. The remaining portion circulates in the air as part of the magnetic path, so it cannot be completely prevented.

However, the impact force is increased by the improved 10 inches, and deterioration in print quality can be reduced.

〔Effect of the invention〕

As explained above, according to the print head according to the present invention, at least two slits are formed in the permanent magnet, the yoke, and the core base. This has the effect of suppressing a decrease in impact force and reducing a decrease in print quality.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a first embodiment of a print head according to the present invention. FIG. 2 is a flat diagram illustrating a second embodiment of the printhead according to the present invention. FIG. 3 is a flat curved view showing a third embodiment of the print head according to the present invention. FIG. 4 is a sectional view taken along the line X--X in FIG. 2. Figure vg5 is a perspective view showing a conventional example of a print head. Figure 8g6 is a plan view of the conventional example. FIG. 7 is a sectional view taken along the Y-Y line in FIG. 6. FIG. 8 is a partially enlarged perspective view of the conventional example. 1...Permanent magnet 2...Yoke 3...Core base 3a...Core 4...Amateur
5... Guide hole 6... Camp 7... Coil plug pufferfish 8... Coil 9... Slit IO... Remainder

Claims (1)

[Claims] 1. A print head comprising a permanent magnet connected to a ferromagnetic yoke and a core base, characterized in that at least two slits are formed in the permanent magnet, the yoke, and the core base.