JPS58188671A - Wire dot printer head - Google Patents

Abstract

PURPOSE:To decrease power consumption for driving and to reduce the rising in a temp., by using a semi-hard magnet material in the magnetic circuit of an electromagnet part for driving the wire of a dot printer. CONSTITUTION:A semi-hard magnet core 10 is used with respect to the electromagnet for driving a wire pin 15. When a pulse current is passed through a coil 12 during the period of a point A- a point C, the core is magnetized and the magnetic flux of the core rises during the period of the point A- the point C. An armature 13 is moved toward the printing position after the point B and printing operation is carried out between a point G- a point H. During this period, when a pulse current with inverse polarity is flowed through the coil between a point D- a point F, the core is demagnetized and the magnetic flux of the core comes to almost zero during the period of the point D- the point F. The armature completing printing operation starts the movement toward a stationary position after the H point because the magnetic flux of the core already comes to zero and returned to the stationary position at a point I while again starts the next repeating operation after a point J.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a semi-hard magnetic material in the magnetic circuit of the electromagnet section for driving the wire in a wire dot printer head to reduce power consumption and temperature rise of the head. It was measured.

In wire dot printers, increasing printing speed and improving printing quality are important technical issues, and various types of wire drive mechanisms are used to address these issues.
The conventional and most widely used type is the electromagnetic type. This attracts the armature with 11 magnets,
The motion of this armature drove the bottle and printed dots. One of the disadvantages of this method is that in order to increase the printing speed, the armature must operate quickly, and the electromagnet must be driven with a large amount of power, which increases the temperature rise of the electromagnet coil.

The present invention aims to improve such problems.

A semi-hard magnetic material is used in the magnetic circuit of the electromagnet, and the armature is operated and restored by magnetizing and demagnetizing parts of the material.

Even in the conventional electromagnetic method, a pulse current of a minimum width sufficient to drive the armature is applied to the electromagnet to reduce the driving power, but the present invention uses a method using semi-hard magnets. Essentially, it is sufficient to apply a driving current with an extremely short pulse width necessary for magnetizing and demagnetizing the magnet, thereby making it possible to reduce the driving power.

A specific example will be explained below. FIG. 1 shows a conventionally used electromagnetic wire drive mechanism, and FIG. 2 is a diagram showing the timing of this operation. The operation of the conventional system will be explained below with reference to both figures. 1st
In the figure, when the core and yoke 1 are excited by the current flowing through the coil 2, the armature 3 is attracted to the right. Therefore, the bin (dot wire) 5 moves to the right together with the armature and presses against the platen 9. At this time, the ribbon 7 and paper 8 are pressurized between the platen 9 and the bottle 50, and dots are printed on the paper using the ink contained in the ribbon. After printing, at this point, the excitation current of the coil is high and the attraction force to the armature is zero, so the repulsive force from the platen, paper, and ribbon and the left >m force in the direction causes the armature to move to the left and return to the initial position &.

The above operation will be explained with reference to FIG. FIG. 2 shows temporal changes in the T waterfall flowing through the coil 2 and temporal changes in the position of the armature 3 that moves in response to this, with the 1-time axis aligned. When a voltage is applied to the coil at point λ on the time axis, the coil current begins to increase. The armature begins to move after point B, where the current increases and the attractive force reaches a certain value, and thereafter rapidly moves toward the printing position.

The armature operating speed must be as high as possible,
Therefore, the current in one coil is a short-term function K after point A,
It is designed to reach a sufficient current value. On the other hand, the temperature rise due to the heat generated by the electromagnet becomes very large, so at point C when the armature is sufficiently accelerated, the voltage applied to the coil becomes zero, and the voltage is applied to the coil again until the 0 point for the next operation. is the off period.

On the other hand, the armature moves in the operating direction at a given speed even after the voltage applied to the coil becomes zero at six points, and reaches the printing position at point D-B.

At this time, the bottle 5 is in a state of pressing against the platen 9.

Printing is performed on paper 8 using ink contained in ribbon 7. After printing is completed, the repulsion force from the Gradeff 1 paper and ribbon, the return force of the OII return spring 4, and K are used.

(At this point, there is no suction force acting on the armature blades) It starts moving toward the rest position, reaches the rest position at point F, and then stops at the rest position after some collision and rebound period. This completes one printing operation, and the next operation begins after the 0 point.

The conventional printing method described above is currently widely used, but one of its problems is that the magnet portion generates a large amount of heat. In order to improve the printing speed, and thus increase the operating speed and acceleration of the armature, a large current is passed through the coil for a short period of time as described above. Therefore, even when the excitation duty cycle is considered, the temperature of the electric stone becomes extremely high, and this is a major factor that limits printing speed. In actual examples, the average power consumption per head reaches 100 Vv or more in some cases.

Next, the operation and features of the wire drive mechanism according to the present invention will be explained with reference to FIGS. S, 4, 5, and 6.

In FIG. 3, 10 is a semi-hard magnet core, 11 is a yoke, and 13 is an armature supported by a return spring 14. Although FIG. 3 is a diagram showing a stationary state, operations are performed in the following order.

When a pulse current is passed through the coil 12, the core 10 is magnetized by the current and enters a magnetized state. Therefore, the armature 13 is attracted to the right by the magnetic circuit consisting of the core 10 and the yoke 11. The bottle 15 also moves to the right together with the armature and presses the platen 19. At this time, dots are printed on the paper 1B by the ink of the ribbon 17.

During this time, when a pulse current of opposite polarity is passed through the coil, the previously magnetized core is demagnetized. By appropriately setting the pulse current value, the residual magnetic flux after demagnetization can be reduced to almost zero.Therefore, no attractive force is applied to the armature, and after dot printing is completed, the armature is free from the platen, paper, and ribbon. It moves to the left and returns to its initial position due to the repulsive force and the leftward return force of the return spring.

The above operation will be explained as follows in conjunction with FIG. When a pulse current is applied to the coil during the period from point KA to point C, the core is magnetized, and the core magnetic flux rises during the period from point A to point C. The armature moves toward the printing position after point B, and performs a printing operation from point G to point H. During this period, when a pulse current of opposite polarity is passed through the coil between points D and F, the core is demagnetized and the core magnetic flux becomes almost zero during the period between points D and F. After completing the printing operation, the armature's core magnetic flux has already become zero, so it starts moving toward the stationary position after H fish, and 1
It returns to the stationary position at point J, and begins the next repeated operation from point J onward.

Next, the magnetization and demagnetization of semi-hard machine stones will be explained with reference to FIG. In the figure, 佽) is a B-H characteristic curve of a semi-hard magnet material, Q)) is a diagram showing the temporal change of an excitation current that magnetizes and demagnetizes a semi-hard magnet material, and (C) is a diagram showing a semi-hard magnet due to an excitation current. It is a figure showing the temporal change of the magnetic flux of a core.

In FIG. 5(a), the semi-hard magnet core is initially in a demagnetized state 11, and the operating point is zero. As explained above, when a pulse current with the maximum value P is applied during the period from point A to point C in the same figure (1), the magnetization state becomes 0 in (1) of the same figure.
After changing from the point in the direction of the arrow and reaching the magnetization state L1 corresponding to the maximum value P of the pulse current, the current reaches point 4 (magnetized state) when the current becomes zero. The magnetic flux of the core changes from point A to point P and 0 in the same figure (C) as the magnetization state changes.
The magnet changes to a point and maintains its magnetized state.

Next, during demagnetization, when a pulse current showing the maximum value Q is applied during the period from point D to point F in the figure (b), the magnetization state changes in the direction of the arrow from point 3 at the top of the figure (1). However, when the pulse current reaches zero after passing through the Ls point, the pulse reaches the zero point (demagnetized state) again. As the magnetization state changes, the magnetic flux of the core changes from point D to point Q to point F in the figure (C), resulting in a demagnetized state. The printing operation according to the present invention shown in FIGS. 3 and 4 is achieved by setting the magnitude of the applied pulse current of positive and reverse polarity so as to obtain a predetermined magnetization state as shown in FIG. It will be understood that this can be achieved by

Figure 6 is another example showing the relationship between exciting current and core magnetic flux when a semi-hard magnet material with so-called composite magnetic properties, which has slightly different magnetic properties than those shown in Figure 5, is used. It is. The configuration shown in FIG. 5 and the operating principle shown in FIG. 4 are exactly the same, but the state of magnetization and demagnetization of the semi-hard magnet material is slightly different. below! Let's explain about the s6 diagram. In the figure, (a) is the B-H characteristic curve of the semi-hard magnet material, (b) is a diagram showing the temporal change of the excitation current that magnetizes and demagnetizes the semi-hard magnet material, and (C) is the diagram showing the semi-hard magnet due to the excitation current. It shows the temporal change in the magnetic flux of the core. In Fig. 46 (-1), the semi-hard magnet core is initially in a demagnetized state and the operating point is at 0 point. When a pulse current showing the maximum value P is applied during the period from point A to point C at Φ in the same figure, the magnetization state changes from point 0 in the direction of the arrow, passes through point L3, and reaches point (layer d-shaped M). Reach K. As the magnetization state changes, the magnetic flux of the core changes from point A to point P to point 0 in the figure (C), and maintains the magnetized state. The operation during this time is the same as in the case of FIG.

Next, during demagnetization, when a pulse current showing the maximum value Q is applied during the period from point D to point F in Figure 6(b), the magnetization state changes in the direction of the arrow from the 1 point at the top of Figure 6(a). L.

When the pulse current becomes zero after passing through this point, it again reaches the 0 point (demagnetized state 11). As the magnetization state changes, the magnetic flux of the core changes from point D to point Q and point F in the figure (C), resulting in a demagnetized state. This is where the advantage of using a material with composite magnetic properties arises. Now, if the magnitude of the pulse current during demagnetization fluctuates, in Figure 6 (b), point D, point Q,
Let's assume that it has grown as shown by the curve at point F. In this case, the change in the magnetization state starts from one point, passes through the L'S point, and reaches the σ point. Has composite magnetic properties,
Since the B-H characteristic curve is stepped between point 1 and point Lz, the maximum value of the pulse current is not at point Q but at point Q' and even if the pulse current fluctuates considerably, the pulse current becomes zero. After that, the residual magnetic flux does not become very large, and is only a variation corresponding to the difference between the 0 point and the 0' point. If a semi-hard magnet material like the one shown in Figure 5(a), which does not have composite magnetic properties, is used, there is a risk of re-magnetization due to residual magnetic flux in the opposite direction when the current value of the demagnetizing pulse becomes large. You can imagine that. Various materials having such composite magnetic properties have been put into practical use, and by selecting a material with appropriate properties, the allowable range of the maximum value of the demagnetizing pulse current can be widened.

According to the above explanation, the printing operation of the armature in FIG. 4 is the same as that in the conventional electromagnet method shown in FIG. 2, but in the method according to the present invention shown in FIG.
It will be understood that the armature is operated by controlling the magnetization state of the core made of a semi-hard magnet by using the Norms current in both the forward and reverse directions. In addition, if you try to generate a magnetic field by an electromagnet without using Norse excitation in the operation equivalent to Figure 4, it is necessary to excite the electromagnet during the period from point A to point D in Figure 4. However, according to Curls excitation, λ
I think it can be understood that it is sufficient to give two short nodules, points from point to point C and point from point D to point F. The period to reach points from point A to point D is generally 200 μs to 500 μs. On the other hand, the required time for magnetizing and demagnetizing a semi-hard magnet is
Depending on the excitation conditions, 50μ3 to 200μm, respectively.
It is possible to reduce the

Therefore, it is clear that the excitation time according to the present invention can be shorter than that of the conventional electromagnetic method, and power consumption can be reduced.

[Brief explanation of the drawing]

Figure 1 shows the wire drive mechanism of a conventionally used electromagnetic wire dot printer head, Figure 2 shows the timing of the operation of the conventional wire drive mechanism shown in Figure 1, and Figure 5 A wire drive mechanism according to the present invention using a semi-hard magnetic material for the core, FIG. 4 is a diagram showing the timing of the operation of the wire drive mechanism according to the present invention shown in FIG.
Figure 5 is a diagram showing the magnetic changes in the magnetic circuit of the same mechanism when a normal semi-hard magnet material is used, and Figure 6 is a diagram showing the magnetic characteristics of a composite type as a semi-hard magnet material. It is a figure which shows the magnetic change when using. 1::f7:tdjhi! -ri, 2: coil, 3 near-gusset island, 4: return spring, 5: pin, 6: guide,
7: Ribbon, 8: Paper, 9 Nibraten, 10: Core, 11
: Yoke, 12; Coil, 15 near-mesh, 14:
Return spring, 15. Hi/, 16: Guide, 17: 11th 3rd exit 2nd field r 4th floor 5th exit (6) 2nd bad boy

Claims (1)

[Claims] (2) A wire dot printer head that uses a semi-hard magnetic material in the magnetic circuit of the electromagnet section for driving the wire. A wire dot printer head characterized in that a material having composite magnetic properties is used as the semi-hard magnetic material.