JPH0336036A - Ink jet printer control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a novel control device for an ink jet printer that presses ink with an electrostrictive element and jets it from a nozzle to form characters and figures in a dot matrix. Concerning configuration.

[Conventional technology]

Although FIG. 3 shows an example according to the prior art, an example of an ink jetting method will first be described with reference to FIGS. 4 and 5.

FIGS. 4(a) to 4(c) are cross-sectional views of the ink jetting mechanism, and the movement of ink is indicated by arrows. Reference numeral 5 designates a nozzle plate having nozzles 7, which holds ink 8 between it and a base material 6. Reference numeral 3 denotes an electrostrictive element which is distorted by an electric field, and is fixed to the base material 6 opposite to the nozzle 7, with electrodes arranged at the left and right ends of the figure (not shown).

(a) is a waiting state in which an electric field is applied to the electrostrictive element 3 to cause the base material 6 to protrude toward the ink side. (b) is gradual 1. : A state in which the electric field is removed; (C) is a state in which an electric field is suddenly applied to cause the ink 8 to be ejected 91 from the nozzle 7;
Arrows in the figure indicate the direction of ink movement.

The reason why the electric field is removed slowly in (1)) is to prevent outside air from being taken in. If outside air enters directly, the ink control Q1 may become impossible.

An embodiment according to the prior art for controlling such an ink sentry mechanism is shown in FIG. 3. In FIG.
It is a high voltage power supply of about 200V. - - represents the output voltage I of the high voltage electric IT, C represents the smoothing capacitor, TR
+ is a transistor that switches the voltage V. This switched voltage is designated as V. 2 is a control circuit for controlling the electrostrictive element 3, and D is a diode for use with other control circuits. R+ is a resistance of several Ω and rapidly charges the parasitic capacitance of the electrostrictive element 3. R2 is a resistor of several tens of ohms, which, as described above, gently sucks out the charge accumulated in the electrostrictive element 3, and is executed by turning on the transistor TRo. 2a is a communication line between the control circuit 2 and the electrostrictive element 3. Rs is number 1
The standby state shown in FIG. 4(a) is set by using a resistor of 0.00Ω to ensure the standby state is maintained even when the body is ejected. Control circuit 2
are provided as many as the number of nozzles. In a conductive serial printer, the number of nozzles is approximately 8 to 48. Reference numeral 4 denotes a drive signal generating means that provides a switch signal and a print signal to the transistors Tr+ and TRo at predetermined timing.

The operation of FIG. 3 is explained with reference to FIGS. 5(a) to 5(C), in which (a) is a periodically repeated switch signal of the transistor T R+. (b) shows the drive f3 waveform that excites the transistor TRo by the print 1 data.

(C) shows the voltage waveform applied to the electrostrictive element 3.

Ink is ejected at the timings marked as ejection and non-ejection.

This was the configuration according to the prior art.

[Problem to be solved by the invention]

However, in the prior art described above, in order to stabilize ink ejection, the control circuit 2 uses a diode D, which is an individual component, and a resistor R11T2+Rs having a significantly different value. this is,
There is no problem until the number of nozzles reaches about 8, but as the number of nozzles increases beyond this point, problems arise in terms of mounting area and failure. Due to the problem of heat dissipation and low resistance, integration (I
It also has the problem that it is difficult to convert into C). Therefore, as the functionality increases, problems arise that result in increased costs.

SUMMARY OF THE INVENTION The present invention aims to solve these problems, and its purpose is to generate a common scanning voltage, and a control circuit to selectively apply the scanning voltage to the electrostrictive element to stabilize ink ejection. An object of the present invention is to provide an inexpensive control device for an ink jet printer.

[Means to solve the problem]

The ink jet printer control device of the present invention is capable of controlling an ink jet printer that rapidly presses ink with an electrostrictive element to cause the ink to be ejected from a nozzle to form characters and figures in a dot matrix. ! ! In this case, a scanning voltage is generated by a scanning voltage generating means consisting of a high voltage power supply and a first and second switching means that share a single coil and short-circuit the main electrodes at 1g''f- in one direction. The first feature is that scanning voltage generation is highly power efficient.

A second feature is that the gate means for selectively applying a scanning voltage to the electrostrictive element also has low power consumption.

A driving signal generating means for giving a signal to the gate means and a scanning control means for controlling the scanning signal generating means in synchronization with the driving signal generating means are added to stably control ink ejection and generate the electric power. A major feature is to provide an ft1l control system for an ink jet printer with a reduction in the number of components that excite the distortion elements and low power consumption.

[Effect]

According to the configuration described in item 4 of the present invention, since the scanning voltage is generated by minimizing energy loss during charging and discharging, including the parasitic capacitance of the electrostrictive element and the capacitance added to the circuit, ink jetting is stabilized. It is possible to obtain an ink jet printer control device that reduces the number of components and consumes less power while controlling the ink jet printer.

〔Example〕

FIG. 1 is a diagram showing a specific configuration used in an embodiment of the present invention, and FIG. 2 is an operational waveform diagram for explaining FIG. 1. , symbols shall have the same meaning.

Reference numeral 10 denotes a scanning voltage generating means which generates a scanning voltage (3). Transistor TR+ is switched with the waveform of FIG. 2(a) to form the rising portion of FIG. 2(C).

CI is a capacitor, which includes additional capacitance and parasitic capacitance of the switched electrostrictive element.

The energy loss in one cycle of charging and discharging the voltage of the capacitor C1 between voltage 0 and Va is CCV·2. The aim is to reduce this loss.

Assuming that the current in when the transistor TR+ is cut off is +Lin2, the energy stored in the coil L is +Lin2. This energy forms a loop with diode D2 and charges capacitor 01. Although a delay occurs in this way, -
Once the energy is stored in the coil, the capacitor C2 is charged to the voltage Vs without being consumed much by the resistance of the circuit, and the energy of +〇IV12 is stored. This is the rising edge of the scanning voltage VS.

Next, a case will be explained in which the capacitor C2 is slowly discharged. The transistor Tr2 is switched as shown in FIG. 2(b). This switch is executed while the detection means 11 compares the scanning voltage vl with a falling reference voltage. Therefore, it is not necessarily periodic as shown in FIG. 2(b). FIG. 2(b) shows the maximum period, and the conduction width of the transistor TRa is constant and the next conduction is such that the reference voltage is higher than the scanning voltage Vs. and be late.

In any case, when the transistor TRz is cut off, the charge in the capacitor C2 is converted into electromagnetic energy in the coil L, which is returned to the smoothing capacitor C through the diode D. At this time, the voltage VS increases, but it is small because the capacity of the smoothing capacitor 0 is made larger than the capacitor CI. The control means of the high voltage power supply 1 limits the input of the unstable power supply to improve the power supply efficiency. Eventually, capacitor 01 follows the change in the reference voltage.
Most of the energy is fed back to the smoothing capacitor C8 to complete the cycle of the scan voltage VS.

In this way, by once accumulating the generated force of the scanning voltage Vl in the coil, more than 80% or more of the force conventionally consumed by the resistance of the system can be recovered.

Conventionally, +CIV I due to system resistance in -2 charging cycles
2. +C+ accumulated in capacitor 01 during the discharge cycle
The energy of Vs2 was consumed by the resistance of the system.

FIG. 2(C) shows the scanning voltage ■$ controlled in this manner.

A scan control means 12 controls the transistors TR1 and TR2, and is connected through al2a and 12b.

The scan control means 12 receives a signal from the scan voltage VS detection means 11 via a line 11a, and receives a synchronization signal from the drive signal generation means 15 via a line 1115b so as to synchronize the scan voltage generation cycle.

Reference numeral 13 denotes a driving section which selectively applies a scanning voltage Vs to the electrostrictive element 3 through a gate 14 . Controlling the gate 14 is performed by the drive signal generating means 15 through a line 15a. Second
Figure (d) shows the increasing number of cycles of the scanning voltage Vl.
FIG. 2(e) shows a control signal to the gate 14 during the standby state, which always fills up the leakage of the electrostrictive element 3 and maintains the standby state when the scanning voltage VS is approximately V.

FIG. 2(f) shows that the control signal to the gate 14 is for ink ejection;
The case of non-injection and injection cycles is shown.

FIG. 2(g) shows the voltage applied to the selected electrostrictive element 3. In FIG. 2, the vertical dotted lines clarify the phase relationship.

As described above, since the conditions are constant simply by using a common scanning voltage Vs and selectively gate the electrostrictive elements, it is possible to stably eject ink from the nozzles.

Note that the reason why the capacitor C1 is the sum of the selected parasitic capacitance and the additional capacitance is that, from the perspective of the scanning voltage generating means 10, the capacitance This is because accurate scanning voltage generation may be impaired due to large load changes. Therefore, in order to reduce the fluctuation rate of the capacitive load, the capacitor is included in the capacitor CI.

Even if the capacitance is increased in this way, the charge is efficiently transferred alternately between the capacitors 0m and C1 while generating an accurate scanning voltage without being consumed by the resistance of the system. Therefore, the supply from the high voltage power supply 1 is not small.

〔Effect of the invention〕

] As stated above, according to the present invention, there is an
(Ink jet 9/na printer control device that efficiently generates a scanning voltage by arranging the i-coil and two switch means to provide directionality, stably reduces the number of components, and consumes low power. The effect of being able to provide this is significant.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a specific configuration in an embodiment of the present invention. FIGS. 2(a) to 2(g) are diagrams showing operating signal waveforms of each part in FIG. 1. FIG. 3 is a diagram showing an example of a configuration according to the prior art. FIGS. 4A to 4C are partial sectional views of an ink jet printer according to the present invention. Figures 5(a) to (C)
3 is a diagram showing operating waveforms of each part in FIG. 3. FIG.

Claims (1)

[Claims] In the control device of an ink jet printer that forms characters and figures in a dot matrix by rapidly pressing ink with an electrostrictive element and ejecting the ink from a nozzle, a high voltage power supply,
Scanning voltage generating means comprising first and second switching means whose main electrodes are connected by a unidirectional element, sharing the only coil that receives the output voltage of the high voltage power supply and applies a scanning voltage to the electrostrictive element. , a gate means for selectively applying the scanning voltage to the electrostrictive element, a drive signal generation means for controlling the gate means, and a scan control means for controlling the scanning signal generation means in synchronization with the drive signal generation means. A control device for an ink jet printer, characterized in that, in addition to stabilizing ink jetting, the number of components excited by the electrostrictive element is reduced and power consumption is reduced.