JPS5983673A - Method for driving electrostriction type printer head - Google Patents

Abstract

PURPOSE:To suppress the residual vibration in the displacement of a wire leading end to a min. degree and to attain to accelerate the speed and to enhance the printing quality of a printer, by lowering the voltage to be applied to an electrostriction type printer head in proportion to time elapse from the predetermined point of time. CONSTITUTION:The strain of an electrostriction element generated by voltage application is transmitted to a wire through a hinge, a lever part and an arm part and a recording medium is struck by the wire to perform printing. In this case, when the time elapsed until the wire is returned to the original position while types the recording medium from the start of the voltage application is set to T, the voltage at the start time of application to Vo, a time to (t) and a minute time interval to T, voltage V to be applied is controlled so as to form a formula. By this method, because a drive voltage wave form is lowered in voltage in proportion to time elapse in the falling part thereof while a time T+DELTAT comes to zero and voltage is slowly fallen, the mechanical system of a printer head easily follows and residual vibration is suppressed to a min. degree.

Description

[Detailed Description of the Invention] What is the present invention? (This relates to a method of driving an impact-type wire tod printer head using an L strain element, and is aimed at suppressing residual dynamic behavior of the wire.

Wire tod printers, which print using the mechanical impact of a wire, can simultaneously copy plain paper (this paper), and because characters are composed of a collection of pixels, they have excellent flexibility in recording not only alphabetical characters, but also kanji and figures. It is widely used because of its advantages such as low price. Conventionally, wire tod printers have mainly been electromagnetic active type, but the drive power is large and when increasing the speed of the printer, the concealment increase due to overcurrent becomes a problem. This was an obstacle to increasing speed.

On the other hand, an impact type wire tod printer using an electrostrictive element is attracting attention because it can theoretically eliminate the drawbacks of the electromagnetic type.

However, in order to print at high speed using either the electromagnetic or electrostrictive methods, the flying wire must hit the platen through the ink ribbon and paper, and at the same time start the next flight. , it is important to minimize residual vibrations when the wire collides with the recording medium and stops. That is, at the start of the second and subsequent flights, the thicker the residual vibration and the larger the amplitude of the previous flight. Since the kinetic energy and strain energy of the printer head are superimposed, the motion energy of the wire increases. In this way, the print density becomes higher from the second time onward, and it becomes impossible to print uniformly.

Hereinafter, a conventional 'KM type printer head and its driving method will be described with reference to FIG. 10J.

Figure 1 shows an example of an impact type wire throat printer head using an electrostrictive element.
The second lever 1 has an electrostrictive element 101 held in
0f and second lever 1.08 are each hinge 103.1
04 &? :N 105.'nt M via 106
It is connected to the element and helad base. Furthermore, the third lever 112 is connected to the second lever via the hinges 111 and 11o.
The arm portion 1 is connected to the third lever.
17, and a wire 114 is connected to this arm portion. Also, stopper 1 for Herad base 1.02
18 are formed. 115/:t ink ribbon, 1
16 is paper, and 117 is a platen. To describe the operating principle of the printer head shown in Fig. 1, the electrostrictive element 1
When a voltage is applied to 01, the electrostrictive element 101 is expanded, the hinges 104 and 105 are compressed, and the hinges 1o3 and 106 are expanded. As a result, m lever 1.07, second lever 7
1o8 rotate in the directions indicated by the arrows. The compression movement is caused by the third lever 112 via the hinges 11.0 and III.
is further transmitted to the wire 1 via the -rm section 113.
14. Then, the wire 114 moves straight in the direction of the arrow and hits the ribbon 115, paper 116, and platen 117 to perform printing. Due to the repulsive force of this impact and the restoring force of the hinge, the wire 114 returns to its original position, completing one reciprocating movement.

Conventionally, electrostrictive printer heads are driven by rectangular voltage waves,
The wire hits the recording medium and returns to its original position (
The time up to this point is defined as one cycle T. ), but at this time, it is difficult to minimize the mechanical strain energy within the printer head, so residual vibrations are generally noticeable. As a conventional example, a blink head of the shape shown in Fig. 1 (period T2 0.48 m5ec) is used.
), time response of 114 displacement of wire tip when heated by 11°C with rectangular voltage wave! Figure 2 shows the single case. Second
Figure (a) shows the time response of the wire tip displacement, Figure 2 (b)
shows the drive voltage waveform of the electrostrictive element, and the voltage is reduced to zero at the time of 0.48 rnsec (1 period T) when the wire returns to its original position. The head used in Figure 2 has a gap of 0.4 between the wire tip and the ribbon, paper, and platen.
0mm, 'f4 (The strain element uses a longitudinal effect inert layer ceramic resonator (width 3, depth 2m - length 18mm) made of zircon lead titanate based material, and the displacement magnification of the head is 42 It's double.

In other words, when a printer head is driven with a conventionally used rectangular voltage wave, the mechanical system of the printer head cannot easily follow sudden electrical changes such as instantaneous voltage drops. , significant strain energy is stored in the hinge, base, and electrostrictive element portions within the head. Therefore, residual vibrations are noticeable. As is well known, if the voltage is reduced to zero at a point away from the vicinity of one period T of the blink head, residual vibrations with a larger amplitude than the residual vibration characteristics shown in FIG. 2 will occur, which is not practical.

In view of this, an object of the present invention is to provide a method for driving an electrostrictive printer head that can minimize the residual vibration of the printer head when the wire attempts to return to its original position.

In this method of driving a stopper type blink head, the displacement of a part of the lever is transmitted to the wire via the arm section, and the wire strikes the recording medium to print. The time it takes to return to the original position after impact is T, and the voltage at the start of application is ■o
When time is t1 and minute time interval is T, when the applied voltage V is 0 x T-ΔIII, ■=V.

When T−△T<t<T×△T! This is a method of driving an electrostrictive blink head having the following characteristics.

FIG. 3 shows a driving voltage waveform of a printer head using an electrostrictive element according to the present invention. The pressure waveform for drive '1 shown in Fig. 3 has the same rising part as the conventional rectangular wave, but the falling part is proportional to the passage of time from a time shorter than △T with respect to the period T of the printer head. The voltage decreases at point f) (T.

It is. When the drive voltage falls slowly in this way, the mechanical system of the printer head easily follows, and for the above-mentioned reason, residual vibrations are suppressed to a minimum.

Next, as an embodiment of the present invention, the characteristic of the first embodiment, similar to that shown in FIG. 2, is the wire tip displacement characteristic using the driving voltage wave according to the present invention. Also, the characteristics indicated by the dotted line are the same as those shown in the conventional figure 2 (0
) shows the wire tip displacement characteristics when using the rectangular driving voltage wave. FIG. 4(b) shows an example of the drive voltage waveform according to the present invention, from a constant 'TK pressure of L7.235v to 0
．． 42rn2, fall cycle 0.48m5ec, 11
The voltage becomes 7.5 V and becomes zero in 0.54 m5ec.

As is clear from FIG. 4, according to the present invention, the residual vibration of the printer head is suppressed to one-third or less compared to the case where a conventional rectangular drive voltage waveform is used. In addition, for the drive type, the fall of the pressure is the period T of the printer head.
This should be done after considering the following, and it is not a good idea to lower it too much. For example, point Q in Figure 3
When driven with a voltage waveform that passed through the printer head, there was no effect of suppressing residual vibration in the printer head.

The drive circuit for this printer head is shown in FIG. That is, this drive circuit includes a switching circuit 120 connected to apply the voltage of a power source 122 to both terminals 123 and 124 of the electrostrictive element 127, and a terminal 123 of the electrostrictive element 127.
, 124 A switching circuit 12 connected to short-circuit both ends.
1, and is controlled by a print control signal va and a signal obtained by inverting it by an inverter circuit 126. Here, in order to control the falling time of the drive voltage mentioned above, a resistor 125 is connected in series between the box, the distortion element terminals 123 and 124, and the switching circuit 121, and the braking capacity of the distortion element 127 is controlled. The time constant determined by the resistance value of the resistor 125 is realized by (a) Tazuko L.

As described in detail above, the present invention can suppress the residual imaging of tip displacement to a minimum, and immediately after the first wave of drive voltage is input, the second wave of i) Since it is possible to input data continuously, it is effective in increasing the speed and print quality of wire tod printers.

[Brief explanation of drawings]

Figure 1 is a diagram showing the configuration of an impact type one-twirled dot pre-head using an electrostrictive element. Figure 2 (a) is a time response characteristic diagram of the wire tip displacement when the printer head shown in Figure 1 is driven with a conventional rectangular voltage wave, and Figure 2 (b) is the drive of the electrostrictive element. Voltage waveform diagram. FIG. 3 is a drive voltage waveform diagram according to the drive method of the present invention. FIG. 4 is a wire tip displacement characteristic diagram using a driving 1ij pressure wave according to the driving voltage cut-off according to the present invention. FIG. 4(0) is a diagram showing an example of a driving voltage waveform according to the present invention. FIG. 5 is a diagram showing a drive circuit for the printer head of the present invention. In the figure, 101 and 127 are electrostrictive elements, and 102 is an electrostrictive element. Debase, J. (13, 104, 105, 106, 110
, Ill are hinges, 107, 108, 112 are respectively the second lever, the second lever, the third lever, 113 is the third lever arm portion, 114 is the wire, 115 is the inkliphone, 116 is the paper, 117 is the platen, and 118 is the stopper. , 120.121 is the switching circuit, 122 is the power supply, 12:
3, 124 is the terminal of the strain element, 125 is the resistor, 12
6 is the impark circuit. Fig. 1 Fig. 2 0 0.2 Q, 4 0.6 08 face f(p
4 (rnseC) Figure 3 Time (ffL 5eC) Figure 4 70 0.2 04 06
'E time (rrb sec)

Claims (1)

[Claims] The distortion of the electrostrictive element caused by the voltage application is transmitted to a part of the lever via the hinge, and the displacement of the part of the lever is transmitted to the wire via the arm part, and the wire holds the recording medium. In the driving method of an electrostrictive printer head that performs printing by impact, the time from when voltage is applied until the wire impacts the recording medium and returns to its original position is T, and ′ at the start of application is When the voltage is ■o and the time is t1 and the minute time interval is △T, the applied voltage is v−v when o<t<'r−△T. A method for driving an electrostrictive printer head, characterized in that T- to T(t(T+ΔT, ■=-(vo/2ΔT)(t-T)+, V.