JPS58168580A - Printing head - Google Patents

Abstract

PURPOSE:To provide a printing head capable of imparting release ampere turn reguired in the release number of an armature, constituted by a mechanism wherein specific bias coils are arranged to a core and mutual bias coil intervals are made electrically parallel. CONSTITUTION:Bias coils 14 are respectively arranged one to every coils 9 and connected to each coils 9 in series magnetically while made independent electrically. In addition, the bias 14 is commonly wired in such a manner that all of said bias coils 4 generate a definite amount of magnetic flux toward a same direction when a current is supplied thereto. By supplying a current to the bias coils 4, it is possible to correct releae ampere turn corresponding to a difficient part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a print head, and particularly to a dot matrix blink print head that is widely used as an output device for information processing devices.

Conventionally, as shown in FIG. 1, a print head of this type has a base plate 1, a permanent magnet 2, a plate 3, a spacer 4,
Each magnetic member, including the plate spring 5 holding the armature 7, the yoke 6, the armature 7, and the core 8, forms one magnetic path, which is divided into multiple magnetic paths by dividing the ring almost equally into the print head. is formed. FIG. 2 is a sectional view of a conventional print head, in which 9 is a coil in the yoke 8, 10 is a wire, 11 is a wire guide, and 12 is a pin guide.

In this way, in the longevity print head, the pace plate 1, the permanent magnet 2, the plate 3, the spacer 4, the leaf spring 5, and the yoke 7 are integrally formed, and each part of the reed and wire 10 is There are only a few independent ones: Amateur 7, Core 8, and Coil 9.

Therefore, the magnetic paths formed by the permanent magnets 2 are not 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. When Amachi Air 7 is released independently, the magnetic flux leaks to the adjacent area and the suction force decreases.As the released uns of the coil 9 interfere with each other, the amount of leakage is limited and the suction force\ does not change. This means that the released ampere-turn is large.

It is clear that there is a difference in the released ampere-turns of the amateurs 7 when the amateur chairs 7 are released individually and when they are released all at once, and a difference in the released ampere-turns due to an increase in the number of releases. However, at present, there is a drawback that the same driving conditions are applied to the coil 9, resulting in variations in print quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a print head that has the same printing quality even when amateurs are released all at once as when they are used alone.

According to the present invention, in a magnetic path composed of a permanent magnet, a yoke, an armature, and a core, magnetic flux in the opposite direction is generated in the core by N current of the coil so as to cancel the magnetic flux of the permanent magnet, and the plate spring In the print head which releases the armature from the core through a plurality of coils, a bias coil is disposed in each of the plurality of coils so as to be magnetically independent of the coil and electrically independent of the coil, and each bias coil is A print head is obtained which is characterized in that the print head is configured such that the print heads are electrically parallel to each other.

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

FIG. 3 is a cross-sectional view of one embodiment of the print head of the present invention, in which a bias coil 14 is added compared to the conventional print head shown in FIG. That is, as shown in FIG. 4, one bias coil 14 is arranged for each coil 9,
Magnetically, each coil 9 is connected in series and electrically independent, and the bias coil 14 is wired in common, so that when the bias coil 14 is energized, all of them generate a certain amount of magnetic flux in the same direction. It is. Therefore Amachia 7
When releasing, it is possible to compensate for the ampere-to-ampere turns required for the release.

In the case of simultaneous release of multiple amateurs 7 compared to single release of amateur 7, even if the attractive force per magnetic path increases due to the increase in the number of releases and the release ampere turn becomes larger, the release ampere corresponding to the increase By applying a turn to the bias coil 14 in advance, it is possible to ensure the same release of the armatures 7 both individually and all at once.

The reason will be explained in more detail with reference to FIG.

Figure 5 shows the turn required for release per 71 armatures and the actual driving ampere turns when the number of armatures 7 released is increased. Take a turn.

First, according to FIG. 5(a), point A is the setting position of the conventional driving ampere turns by the coil 9, and at point B and point 0, the ampere turns required for release increase, so A
If the driving ampere turns are the same as the point, the released energy will be insufficient. Therefore, in terms of print quality, point A is best, point B is good,
Get the result 5- where 0 points is bad. However, by applying an initial ampere turn NIo to the bias coil 14, the drive ampere turn NIL
-1-NIo and move to point B, point B limits the initial ampere turn NIo to the bias coil 14 by the number of releases n, and when the amateur 7 is released individually and when n amateurs 7 are released simultaneously. In this case, by matching the driving ampere turns to the ampere turns required for release, it is possible to improve the print quality from best at point A and 0 to good at point B. In the same figure, the thick line connecting the driving ampere turns A, B, and C indicates the ampere turns required for release.

As explained above, the present invention makes it possible to provide the release ampere turn necessary for the number of amateurs to release, even when the amateurs are released individually and simultaneously, and even when the number of releases is increased. The release action is uniform and free of flapping, making it possible to guarantee good print quality.

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[Brief explanation of drawings]

Fig. 1 is an assembly diagram showing the magnetic circuit section of a conventional print head, Fig. 2 is a sectional view of the print head shown in Fig. 1, and Fig. 3 is a print head showing an embodiment of the present invention. FIG. 3 is a diagram showing the relationship between ampere turns and the number of released amachias. 1...Pace plate, 2...Permanent magnet, 3...Plate, 4...Spacer, 5...Plate spring, 6... ...York, 7.
...Amateur, 8...Core, 9...
...Coil, 10...Wire, 11...
...Wire guide, 12...Bin guide, 13
...Screw, 14...Bias coil. =7- #3 Times 4 Figure 1 几 Rei (cL) Rate Cb) 5 Figure

Claims (1)

[Claims] Generating magnetic flux in the opposite direction in the core by energizing the coil so as 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;
In the print head in which the armature is released from the core via a leaf spring, a bias coil is disposed in each of the plurality of coils magnetically in series with the coil and electrically independent with respect to the core, and bias coils are disposed in each of the plurality of coils so as to separate each other. A print head characterized in that bias coils are configured to be electrically parallel.