JPS6260659A - Printing head - Google Patents

Abstract

PURPOSE:To enable the release operation of an armature to be made always under same condition and the best printing quality to be always warranted by constituting an auxiliary coil on all the cores other than those involved when more than one or all of the armatures are released at once. CONSTITUTION:A printing head has auxiliary coils 14(14-1-14-n-1) added to the external circumference of a coil 9. If the maximum number required for the simultaneous release of all amatures 7 is (n), one piece of coil 9-1 and n-1 pieces of auxiliary coil 14(14-1-14-n-1) are arranged on, say, the first core 8-1. Each coil is electrically independent, but the auxiliary coils are magnetically connected in series to the coil 9-1. That is, they are so arranged that their magnetic fluxes may work in the same direction. This arrangement applies to all the (n) pieces of core 8-1-8-n alike. In the meantime, 91 pieces of coil and each one piece of auxiliary coil 14 totaling (n) pieces of coil are connected electrically in series between each core 8-1-8-n.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a print head, and particularly to a print head for a dot matrix printer that is widely used as an output device for information processing devices.

[Conventional technology]

Conventionally, this type of print head, as shown in FIGS. 4 and 5, includes a pace plate 1 (in which a core 8 with a plurality of coils 9 is installed), a permanent magnet 2. Plate 3, spacer 4. Leaf spring 5 holding armature 7, yoke 6, armature 7
Each magnetic member of the core 8 (which holds the wire 10) forms one magnetic path, which is divided into a plurality of magnetic paths by approximately equally dividing the ring to form a print head. The print head further includes a wire guide 11 as shown in FIG.
．． A pin guide 12 is provided and the whole is fixed with screws 13.

[Problems to be solved]

In such a print head, while ensuring the necessary functions, the pace plate 1. Permanent magnet 2. Plate 3. Spacer 4. Leaf spring 5. The yoke 6 is an integral member, and there are only a few independent members for each wire 10, such as the armature 7, the core 8° coil 9. Coil 9 (
9-1 to 9-n) are shown in FIG. 6.

Therefore, the magnetic paths formed by the permanent magnets 2 are never completely independent, but are always in contact with adjacent magnetic paths, and the influence of leakage magnetic flux between the magnetic paths cannot be ignored. That is, when the armature 7 is released alone, the attractive force is reduced due to magnetic flux leakage to the adjacent magnetic path, so the release ampere turns of the coils 9 (9-1 to 9-n) are small.

On the other hand, when multiple Amachi airs 7 are released at the same time, the leakage magnetic flux to the adjacent ones interferes with each other as described above, so the amount of leakage is limited and there is no change in the attractive force, and the release ampere turn of the coil 9 is That means it's big.

In other words, it is clear that there is a difference in the released ampere-turns of the amateurs 7 when the amateurs 7 are released individually and when they are released all at once, and that there is also a difference in the released ampere-turns due to an increase in the number of amateurs 7 that are released. However, in the current situation, the same driving conditions are applied to the coil 9 in the case of simultaneous release as in the case of individual release, so there is a problem that the print quality varies.

[Means for solving problems]

The present invention solves the above problems, and includes permanent magnets,
In order to cancel the magnetic flux of the permanent magnet in a magnetic path composed of a yoke, an armature, and a core, a magnetic flux in the opposite direction to the a-flux of the permanent magnet is generated in the core by energizing the coil, and In a print head that releases the armature from the core and performs printing, one end of the coil relative to the core is electrically connected in series to each core other than the core as an auxiliary coil, In addition, similar auxiliary coils are configured for all cores other than the cores that are targeted when one or more armatures or armatures are released all at once.

〔Example〕

Next, the embodiment will be described with reference to FIGS. 1 to 3.

FIGS. 1 and 2 are a longitudinal section of an embodiment of the print head according to the present invention and a wiring diagram of its auxiliary coil, respectively, and FIG. 3 is a diagram showing the released ampere-turns per armature with respect to the increase in the number of armatures released. This is a diagram showing the relationship with actual drive ampere turns, and the same parts in FIG. 1 as in FIG. 4 are given the same reference numerals, and their explanation will be omitted.

In Fig. 1, the print head is different from the conventional print head.
Auxiliary coils 14 (14-1 to 14-n
-1) has been added.

According to this, the maximum number of amateur 7 to be released all at once is n
When looking at the first core 8-1, 1
coils 9-1 and n-1 auxiliary coils 14 (14
-1 to 14-n-1) are arranged, and each coil is electrically independent, but magnetically the coil 9-1
It is in series with In other words, they are arranged so that all magnetic fluxes work in the same direction. This is n cores 8-1
-13-n are all configured in the same way.

Further, between each of the cores 8-1 to 8-n, 91 coils and one auxiliary coil 14, for a total of n coils, are electrically connected in series.

Therefore, in the case of independent release of the armature 7, for example, when one coil 9-1 is driven, magnetic flux is generated in the core 8-1 including this coil 9-1, and the other cores 8-2 to 8-
Magnetic flux is also generated by each of the auxiliary coils 14-1 to 14-n-1 connected in series with the coil 9-1. Furthermore, if the number of released amateur 7 increases, the same core 8
The number of auxiliary coils 14 included in the auxiliary coils 14 that generate magnetic flux increases in proportion to the number of releases.

As a result, the drive ampere turns increase in proportion to the number of releases, and even if the number of releases changes, the drive ampere turns also change, making it possible to automatically supply the amount of ampere turns required for release.

Here, a more detailed explanation will be given using FIG. 3. FIG. 3 shows the relationship between the ampere turns required to release 71 armatures and the actual drive ampere turns when the number of armatures 7 released (1 to n) is increased.

The horizontal axis shows the number of releases of amateur 7, and the vertical axis shows the ampere turn. The ampere-turns required to release the amateur 7 are NtI*-NnI when the amateur 7 is released alone, and the ampere-turns released due to an increase in the number of releases in the middle can be approximated on a straight line n connecting the two.

First, the number of turns of the coil 9 and the number of turns aQ of the auxiliary coil 14.
Then, when only the auxiliary coil 14 is driven, the drive ampere turns will be ao(n-1)I, but the armature 7 will not operate because it does not reach the ampere turns Nl■ required to release the armature 7. In other words, N+I > ao
(n-1) It is.

On the other hand, a case where the amateur 7 operates will be explained. In the conventional example shown in FIG. 6, the drive ampere turn has the same NoI whether it is released individually or simultaneously, and this is shown in FIG. Therefore, in the figure, if No-N1 is set, the printing quality is the best because the ampere turns necessary for individual release (n = 1) can be secured.This is point A, but when - simultaneous release, the necessary release The ampere turn was not reached and the printing quality was the worst, giving it a score of 0.

However, in the present invention, the case of single release is the same as the conventional one, but when the number of releases gradually increases to a maximum of n, the driving ampere turns are NOI + aO(n-
1) I, No = Ns ao (n-1)
By setting the number of turns of the auxiliary coil so that = Nn - N1, it is possible to match the released ampere turns, which is the third rg! It is point B in J.

In Fig. 3, with respect to the ampere turn line ■ required to release the armature 7, only the line π was possible with the conventional drive ampere turn, but in the case of the present invention, the drive ampere turn can also be made. Since the lines can be matched with the ruled lines, the best print quality can always be provided regardless of the number of releases.

〔Effect of the invention〕

As explained above, the present invention makes it possible to provide the release ampere turn necessary for the number of amateurs to release, even in the case of individual release and simultaneous release of amateurs, and even in the case of an increase in the number of amateurs. There is an advantage that the release operation is always performed under the same conditions and that it is possible to always guarantee the best printing quality.

[Brief explanation of drawings]

1 and 2 are longitudinal sectional views of an embodiment of the print head according to the present invention and a wiring diagram of its auxiliary coil, respectively, and FIG. 3 shows the released ampere-turns per armature with respect to the increase in the number of armatures released. FIG. 4 and FIG. 5 are a longitudinal sectional view and an exploded perspective view of the main parts of a conventional print head, respectively, and FIG. 6 is a wiring diagram of the coil.

Claims (1)

[Claims] In order to cancel the magnetic flux of the permanent magnet in a magnetic path composed of a permanent magnet, a yoke, an armature, and a core, a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet is generated in the core by energizing the coil, and a magnetic flux is generated in the core through a leaf spring. In the print head which releases the armature from the core and performs printing, one end of the coil relative to the core is electrically connected in series to each core other than the core as an auxiliary coil, and A print head characterized in that a similar auxiliary coil is constructed for all cores other than the core that is targeted when one or more armatures or armatures are released all at once.