JPS60168661A - Printing head for wire dot printer - Google Patents

Abstract

PURPOSE:To permit high-speed, highly accurate printing by a method in which the yoke and armature of a magnetic circuit constituting a printing head are shaped into an uneven form, and the uneven portions are coupled with each other with formation of faced portions of 4 or more. CONSTITUTION:For the shape of the yoke 13 and armature 14 constituting a magnetic circuit, recessions 15a and 15b are formed between the projections 13a, 13b and 13c of the yoke 13, and a recession 16 is formed between the projections 14a and 14b of the armature 14. In driving the armature 14, under the condition that the projection 13c of the yoke is coupled with the recession 16 of the armature and the projections 14a and 14b of the armature are coupled with the recessions 15a and 15b of the yoke, the inside face 13d of the yoke is faced the outside faces 14d and 14e of the armature and the side faces 13f and 13g of the yoke are faced the inside faces 14f and 14g of the armature to form the 4-faced sides. The flow of magnetic flux in the magnetic circuit can thus be improved to permit high-speed, highly accurate printing.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a print head used in a wire dot printer;
In particular, the present invention relates to a print head for a wire dot printer that uses a large number of arranged printing wires and is configured to print characters such as Chinese characters at high speed and with high precision.

Structure of conventional examples and their problems In recent years, information processing by computers has progressed due to advances in computers and peripheral technology, and in the field of office automation, there is a need for kanji information processing that takes advantage of the characteristics of Japanese that are easy to read and understand. It is increasing. Along with this, the development of various printers is progressing, and among these printers, wire dot printers that can print on various types of paper and are inexpensive are rapidly developing. Therefore, as a print head for wire dot printers, a wire dot type print head for kanji printers has been developed in which multiple printing wires and drive elements are arranged.
Measures such as higher speed, smaller size, and lower noise are desired.

A conventional print head for a wire dot printer will be explained below.

FIG. 1 is an external perspective view of a first conventional print head for wire dot printers. Note that the print head for wire dot printers is constructed by, for example, arranging a plurality of the above print heads in an annular shape. In FIG. 1, 1 is a core wound with 30 degaussing coils, and 2 is a yoke that is fixed to one end of a permanent magnet 4 and is integrated with the core 1 in order to guide the magnetic flux from the permanent magnet 4 to a plurality of cores 1. , 5 is a yoke bonded to the other end of the permanent magnet 4 via a driving plate spring 7, and serves to guide the magnetic flux from the permanent magnet 4 to the magnetic gap. Reference numeral 6 denotes an armature installed in the magnetic gap between the core 1 and the yoke 6. This armature 6 is attached to the yoke 5 via a driving plate spring 7, and a printing wire 8 is attached to the other end of the armature 6 via a driving plate spring 7, thereby forming a printing wire movable section.

The operating principle of the conventional wire dot printer print head configured as described above will be explained.

This print head for wire dot printers employs a spring-charge type printing wire drive system that utilizes the restoring force of a spring, and includes a printing wire movable section consisting of an armature 6 and a driving plate spring 7, and a permanent magnet 4. Core 1. It consists of a yoke 6 and a magnetic circuit consisting of a degaussing coil 3, and the armature 6 installed in the magnetic gap is normally attracted to the core 1 by the magnetic field of the permanent magnet 4.

In this state, the driving leaf spring 7 is in a bent state and accumulates elastic energy. Then, in response to the print signal, a permanent magnet 4 is attached to a degaussing coil 3 wound around the outer circumference of the core 1.
By passing a current in a direction that cancels out the magnetic field, the attractive force of the permanent magnet 4 is canceled out, the elastic energy of the driving plate spring 70 is released, and the printing wire 8 protrudes from the guide surface. At this time, the ink on the ink ribbon is transferred to the printing paper by the impact of the printing wire 8, and is colored in dots. Next, when the current to the degaussing coil 3 is cut off, the armature 6 is attracted again by the attractive force of the permanent magnet 4, and the printing wire 8 is returned to its original position. With the above operations, one dot cycle is completed.

The structure and operating principle of the conventional print head for wire dot printers have been described above. Next, the advantages and disadvantages of the above-mentioned head will be described below.

The advantage is that the driving plate spring 70 is used as printing energy.
By using elastic energy, printing energy can be mechanically set and easily controlled.

In addition, when the printing wire 8 starts moving, the deflection of the drive leaf spring 7 is at its maximum, so the maximum acceleration can be obtained.Furthermore, since the permanent magnet 4 is used to attract the armature 6, Since the armature 6 is attracted by the permanent magnet 4 when the printing wire 8 returns, so-called chattering (double striking due to the armature bounce phenomenon) is reduced, resulting in high printing quality.

High-speed printing is possible.

However, when trying to realize an ultra-high-speed print head that further increases the printing speed using a print head with a conventional magnetic circuit structure as shown in Figure 1 of the housing, it is necessary to use a permanent magnet 4° yoke 5. It is necessary to increase the attraction force of the magnetic circuit made up of the degaussing coil 3, and to increase the printing speed by increasing the attraction force. In the case of the current magnetic circuit for printing, the shapes of the yoke 6° armature 6 and the core 1 that constitute the magnetic path are constructed as shown in FIG. The attraction force acting on the armature 6 here is obtained by the magnetic flux flowing through the yoke 6, the armature 6, and the core 1. At this time, as a way to improve the attraction force, the armature 6 is moved in the same direction as the armature drive direction. The length la of the facing surface of the yoke 50 is increased to increase the facing area, and the magnetic gear knob (lc) is minimized.

Furthermore, the magnetic gear knobs eb and 5d formed downward with respect to the near driving direction of the amateur mf are ed<<lb
I need to be in charge of O music.

However, in the case of the conventional magnetic circuit shape, there is a limit to increasing the facing area of the armature 6 and the yoke 5 because of the problem of an increase in the weight of the armature 6. Furthermore, in the case of the conventional magnetic circuit configuration, as is clear from Figure 1, the opposing area of the two yokes with different magnetic poles is large, which increases magnetic leakage, and even in a pigeon house with a large magnetic circuit force. However, there were problems in that it was difficult to increase the printing speed because the suction force could not be improved.

FIG. 3 is an external perspective view of a second conventional dot printer print head having a magnetic circuit which solves the second problem and improves the attraction force. This will be explained below using FIG.

In FIG. 3, the same sections as in FIG. 1 are given the same numbers and their explanations will be omitted. Also, the difference from Fig. 1 is that the integral yoke 2°9 has the same magnetic poles on the outer yoke to reduce leakage magnetic flux, and the permanent magnet 10 that is cut into the inner circumferential surface of the integral yoke 9. I was able to take the yoke 11 and prepare it. With this configuration, the yoke 11
Since the surface area of the yoke 11 that leaks from the yoke to the outer yokes 2 and 9 can be kept small, the leakage magnetic flux from the yoke 11 to the outer yokes 2 and 9 with different magnetic poles can be reduced, thereby reducing the attractive force. This is something that can be improved.

Furthermore, as shown in FIG. 4, the yoke 11 of the magnetic circuit for wire dot printers is divided into each amateur, and the distance between each yoke is set to ee to reduce the influence of magnetic field fluctuations on other amateurs during printing. This structure solves the problem of an increase in open circuit current when a large number of dots are printed simultaneously (hereinafter referred to as the number of simultaneously printed dots) due to magnetic interference between each wire of the magnetic circuit for driving the printing wire. Therefore, it is possible to reduce the flow rate regardless of the number of dots printed simultaneously.

Incidentally, "open" Ichihara refers to the current necessary to flow through the degaussing coil 3 in order to open the driving leaf spring 7.

However, the yoke 1 constituting the i-path of the magnetic circuit
1 or yoke 12. The shape of amateur 6 and core 1 is
The shape of the magnetic circuit is the same as that shown in FIG. 2, and in order to improve the flow of magnetic flux, armature 6 and yoke 11.
If an attempt was made to increase the opposing area of 12, there were problems in that the armature weight would increase and the printing speed would decrease.

OBJECTS OF THE INVENTION The present invention improves the magnetic flux flow of the conventional spring-charged printing wire driving magnetic circuit to improve the attractive force.
The object of the present invention is to provide a print head for a small wire door printer that can print characters at high speed and with high precision.

Structure of the Invention In order to achieve the above object, the present invention includes a yoke that supplies magnetic flux obtained from a permanent magnet to a plurality of armatures, and a plurality of yokes around which degaussing coils are wound, which are disposed opposite to each armature. A magnetic circuit for a wire dot printer constituted by a core, etc., and a concavo-convex portion in which the yoke and the armature are inserted into each other, and which forms four or more opposing surfaces of the armature and the yoke. This improves the flow of magnetic flux between the yoke, armature, and core, and improves the attractive force of the magnetic circuit for the print head, allowing characters to be printed at high speed and with high precision. This makes it possible to realize a small print head for wire dot printers.

DESCRIPTION OF THE EMBODIMENTS FIG. 6 is a structural sectional view showing the shapes of the yoke, armature, etc. constituting the magnetic circuit of the print head of a dot printer according to the first embodiment of the present invention.

In FIG. 6, 13 is a yoke that supplies the magnetic flux obtained from the magnet 11 shown in FIG. 3 to the armature 14, and the magnetic flux supplied to the armature 14 is
Core 1 around which degaussing coil 3 is wound is arranged opposite to 4.
It has a structure that flows.

The configuration of the yoke 13 and the armature 14 will be described in detail below. 13a and 13b are yoke protrusions provided on both sides of the yoke 13, and 13c is a central protrusion provided in the central recess of the yoke 13.
3c and a recessed portion 15a.

15b is formed. 14a and 14b are armature convex parts provided on both sides of the armature 14 and forming a four part 16 in the center, and a recess 16c of the armature 14 is fitted into the center part 13c, and the armature convex part 14a.

When the armature 14b is fitted into the recesses 1sa and 1esb, the armature 14 can move up and down, and due to the above fitting, the inner surface 13d of the yoke protrusion 13a
, 13e and the armature convex portion 14a.

The outer surfaces 14d and 14e of the central convex portion 13c face each other, and the side surfaces 1af and 13g of the central protrusion 13c and the inner surface 14f of the armature convex portions 14a and 14b.

14g are opposed to each other, forming four opposing surfaces.

With the above-mentioned second configuration, in this embodiment, the opposing surfaces of the armature 14 and the yoke 13 that face each other when the armature 14 is driven are increased compared to the conventional art, so that the opposing area can be minimized. ．． core 1
The flow of magnetic flux improves.

FIG. 6 is a suction characteristic diagram showing the relationship between the length of the gap between the armature and the yoke and the suction force.

In FIG. 6, the solid line represents the attractive force characteristic of the magnetic circuit in the first embodiment, the dotted line υ) represents the attractive force characteristic of the conventional magnetic circuit shown in FIG. 1, and as shown in FIG. The attractive power of the magnetic circuit has been improved.

Incidentally, the dash-dotted line 1 is the attraction characteristic of the conventional magnetic circuit shown in FIG.

Next, a dot printer print head according to a second embodiment of the present invention will be described with reference to FIG.

Figure 7 (-) shows the yoke 1 divided for each amateur.
7 is a top view of a yoke in which a plurality of yokes 17 are arranged in an annular shape. Second
This embodiment differs from the first embodiment in that the yoke is divided and arranged for each armature at a distance of 4f, similar to the yoke 12 shown in FIG. This makes it possible to reduce the influence of magnetic field fluctuations on other amateurs during printing. Also, in this embodiment, since the area facing the yoke and the armature can be increased, the attractive force is increased and the shape of the yoke constituting the magnetic circuit can be made smaller, and the distance between each yoke is 4f.
Since it is possible to obtain a large value, magnetic interference can be significantly reduced.

FIG. 8 is a characteristic diagram showing the relationship between the number of simultaneously printed dots and the open current, which determines the degree of magnetic interference. In Figure 8,
The solid line Ino shows the characteristics of the magnetic circuit when using yoke 17.
The dotted line is the characteristic of the conventional magnetic circuit shown in FIG. 1, and the dashed line is the characteristic of the conventional magnetic circuit shown in FIG.

In the above embodiment, the yoke 13, 1a has a recess 2.
Furthermore, although the armature 14 is provided with one recess and two protrusions, it goes without saying that the yoke 13° 17 and the armature 14 may additionally be provided with additional recesses and recesses. Effects As described above, the present invention provides uneven portions on the yoke and armature of the magnetic circuit constituting the print head, and engages the uneven portions of the armature opposite to the uneven portions of the yoke so that the armature can be driven. By making the shape so that there are four or more surfaces facing the yoke, it is possible to improve the flow of magnetic flux in the conventional spring-charged printing wire drive magnetic circuit and improve the attractive force. This makes it possible to realize a print head for wire dot printers that can print characters at high speed and with high precision.

Furthermore, when the magnetic circuit is shaped as described above, it is possible to improve the suction force with the same volume as the conventional armature, and at the same time, the shape of the armature and yoke can be made smaller, making it possible to realize a smaller print head. Furthermore, if the yoke of one magnetic circuit is divided into armatures, the distance between each yoke can be increased, so the magnetic field fluctuations for other armatures during printing can be maintained without reducing the attractive force characteristics of the magnetic circuit for the print head. This makes it possible to reduce the influence of

[Brief explanation of drawings]

Fig. 1 is an external perspective view of the print head for the first conventional wire dot printer; Fig. 4 (-) is an enlarged external perspective view of the yoke shown in Fig. 3, and (in Fig. 4) is a print head based on the magnetic circuit shape of Fig. 3. FIG. 6 is a cross-sectional view of the structure of the magnetic circuit of the print head for a wire dot printer according to the first embodiment of the present invention. FIG. A suction characteristic diagram showing the relationship between length and suction force. FIG. A plan view of the yoke in the case where a plurality of divided yokes shown in figure (-) are arranged in an annular shape, No. 8
The figure is a characteristic diagram showing the relationship between the number of simultaneously printed dots and the open circuit current of a print head for a wire dot printer. 1...Core, 2.13...Yoke, 3
... Demagnetizing coil, 4 ... Permanent magnet, 1
3a, 13b... Yoke convex portion, 13C...
...Central convex part, 14...Amateur, 14a1
14b...Front edge; A convex portion, 15a. 15b, 16... recesses. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 5 Figure 3 Figure 6

Claims (2)

[Claims] (1) Magnetic circuit for wire dot printers consisting of a yoke that supplies magnetic flux obtained from a permanent magnet to multiple armatures, and multiple cores around which degaussing coils are wound, which are placed opposite to each armature. The yoke and the armature described above are inserted into each other, and the yoke and the armature are provided with uneven portions forming four or more opposing surfaces of the armature and the yoke. Print head for wire dot printers. (2) The print head for a wire dot printer according to claim 1, characterized in that the yoke of the magnetic circuit for the wire dot printer is divided for each armature.