TWI513170B - Power supply control integrated circuit for piezoelectrically actuated nozzle - Google Patents

Description

Power supply control integrated circuit for piezoelectric actuator

The present invention relates to a power supply device, and more particularly to a power supply control integrated circuit for a piezoelectric actuator.

A typical inkjet printer will include a piezoelectric actuator to eject ink droplets via its periodic high speed motion. Piezoelectric actuators typically require a high voltage AC voltage to act on them to drive the piezoelectric actuators to perform periodic high speed motion. Using a high voltage AC voltage to drive the piezoelectric actuator, the piezoelectric actuator can output a periodic control signal to a single-hole inkjet or porous inkjet vibrating plate to drive a single-hole inkjet vibrating plate or porous inkjet vibration. The sheet is periodically moved, thereby ejecting ink droplets through a single orifice nozzle or a porous nozzle of an ink jet printer. In addition, piezoelectric actuators can be applied to micro-dispensing pipette devices, such as biochemical medical laboratory instruments or industrial dispensing equipment, in addition to inkjet printers that can be applied to single-hole nozzles or multi-hole nozzles. Wait.

The power supply device for power-driven piezoelectric actuators is composed of a DC-DC conversion circuit and a DC-AC conversion circuit, wherein the DC-DC conversion circuit and the DC-AC conversion circuit are independent of each other. Separation circuit. Therefore, it is known that a power supply device for power-driven piezoelectric actuators requires a large amount of use. Electronic components require a coil type transformer, which in turn causes a disadvantage of an increase in board area and an increase in manufacturing cost. An example of a conventional power supply device for power-driven piezoelectric actuators is shown in the first figure, which is a conventional DC-AC conversion circuit 100 for a piezoelectric actuator. As shown in the first figure, the DC-AC conversion circuit 100 includes a timing generation circuit 102, switching elements Q102, Q104, a resonance circuit composed of a resonance capacitor C101 and a resonance inductor L101, and a transformer T102. The switching elements Q102, Q104 are set to receive the DC input voltage Vdc, and the switching control signal provided by the timing generating circuit 102 allows the energy of the DC input voltage Vdc to be transferred to the primary side of the transformer T102. The resonant circuit (L101, C101) is set to generate resonance to transfer the energy of the DC input voltage Vdc to the primary side of the transformer T102. The transformer T102 induces an alternating voltage Vac on its secondary side winding according to the turns ratio of its primary side winding to the secondary side winding. The AC voltage Vac is used to drive a piezoelectric actuator (not shown). However, the DC-AC boost converter circuit 100 of the first figure is boosted by purely utilizing the turns ratio of the transformer T102, and the boosting capability thereof is insufficient to drive the piezoelectric of the ink jet printer of the single-hole head or the multi-hole head. Actuator.

The second figure shows another conventional power supply device for powering a piezoelectric actuator. As shown in the second figure, the DC-AC conversion circuit 200 includes a detection circuit IC2, a switching control circuit IC1, switching elements Q206, Q208, a transformer T1, and an output filter circuit (L1, L2, C6) for driving a Piezoelectric actuator PZT. The detecting circuit IC2 is used to detect the output voltage of the DC-AC converting circuit 200. The switching control circuit IC1 generates a switching control signal according to the detection result generated by the detecting circuit IC2 to control switching switching of the switching elements Q206 and Q208. The energy of the input voltage Vdc is transmitted through the switching element Q206, the switching of the Q208 is transmitted to the primary side of the transformer T1, and the switching of the switching elements Q206, 0208 is transmitted to the secondary side of the transformer T1, This produces an alternating voltage on the secondary side of transformer T1. The AC voltage generated on the secondary side of the transformer T1 filters out the noise via the output filters (L1, L2, C6), and generates an output AC voltage to drive the piezoelectric actuator PZT. However, the DC-AC conversion circuit 200 of the second figure is disadvantageous in that a large number of circuit elements are required, and a coil type transformer is still required for voltage conversion. Therefore, the DC-AC boost converter circuit 200 of the second figure is disadvantageous in the application of driving the piezoelectric actuator.

The applicant proposes a power supply control integrated circuit for a piezoelectric actuator, which is used for driving a piezoelectric actuator, wherein the power supply control integrated circuit of the piezoelectric actuator is provided by a DC-DC boost regulation unit. And a DC-AC output control unit is integrated into an integrated circuit, so that the number of circuit components is reduced, the circuit design complexity is reduced, the coil type transformer is not required, the power conversion efficiency is improved, and the manufacturing cost is reduced.

The purpose of the present invention is to provide a power supply control integration circuit for a piezoelectric actuator, which comprises a DC-DC boost regulation unit and a DC-AC output control unit, and the DC-DC boost regulation unit is used for A low voltage DC voltage is boosted to a high voltage DC voltage, and the DC-AC output control unit is coupled to the DC-DC boost regulation unit to convert the high voltage DC voltage to an AC voltage. The DC-DC boost regulating unit is composed of a part of an integrated circuit chip and a passive circuit component, and the DC-AC output control unit is composed of another part of the integrated circuit chip.

100‧‧‧DC-AC boost converter circuit

102‧‧‧ Timing generation circuit

Q102, Q104‧‧‧Switching elements

C101‧‧‧Resonant capacitor C101

L101‧‧‧Resonant Inductor L101

T102‧‧‧Transformer T102

200‧‧‧DC-AC boost converter circuit

IC1‧‧‧Switching Control Circuit

IC2‧‧‧Detection Circuit

Q206, Q208‧‧‧ Switching components

T1‧‧‧ transformer

L1, L2, C6‧‧‧ output filter circuit

PZT‧‧‧ Piezoelectric Actuator

300‧‧‧Power supply control integration circuit

302‧‧‧Integrated circuit chip

304‧‧‧DC-DC boost regulator

306‧‧‧DC-AC output control unit

600‧‧‧ Piezoelectric actuator

602‧‧‧Ink droplets

604‧‧Ink storage tank

606‧‧‧ Piezoelectric Actuator

608‧‧‧Nozzle

700‧‧‧Soft printed circuit board

702,704‧‧‧electrode

First: a DC-AC conversion circuit for a piezoelectric actuator; second diagram: Another DC-AC conversion power conventionally used for power-driven piezoelectric actuators The third diagram is a circuit diagram of a preferred embodiment of the power supply control integration circuit of the piezoelectric actuator of the present invention; the fourth diagram (A): waveform diagrams of the control signals Ca, Cb, Ea, Eb; Figure (B): Waveform diagram of output voltages Oa1, Ob1, Oa2, Ob2, and waveforms of actual output voltages Oa1-Oa2, Ob1-Ob2; Fifth: Scan voltage of actual output voltage Oa1-Oa2 or Ob1-Ob2 Waveform diagram; sixth diagram: an external view of the piezoelectric actuator of the present invention and a power supply control integration circuit; and a seventh diagram: a top view of the piezoelectric actuator.

An exemplary embodiment embodying the features and advantages of the present invention will be described in detail in the following description. It is to be understood that the present invention is capable of various modifications in the various aspects of the present invention, and the description and drawings are intended to be illustrative and not limiting.

The third figure shows a circuit diagram of a preferred embodiment of the invention. As shown in the third figure, a power supply control integration circuit 300 is provided for converting a low voltage DC voltage to at least one set of high voltage AC voltages to drive a piezoelectric actuator. As shown in the third figure, an integrated circuit chip 302 is provided to convert a low voltage DC voltage Vdc into a high voltage AC voltage. The integration circuit 300 includes a DC-DC boost regulation unit 304 and a DC-AC output control unit 306. A portion of the integrated circuit chip 302 and the passive circuit component constitute a DC-DC boost regulation unit 304, and another portion of the integrated circuit die 302 constitutes a DC-AC output control unit 306. The DC-DC boost regulating unit 304 is configured to boost the low-voltage DC voltage Vdc into a high-voltage DC voltage Vo, wherein the low-voltage is straight The voltage value of the stream voltage Vdc is about 2.7V-10V and the voltage value of the high voltage DC voltage Vo is about 40V. The high-voltage DC voltage Vo can be calculated according to the following formula: Vo=1.225×(R1/(R2+R3)+1) (Formula 1) or calculated according to the following formula: Vo=1.225×(R1/(R2+VR1)+ 1) (Equation 2) wherein the resistor R3 and the variable resistor VR1 in the DC-DC boost regulation unit 304 are an alternative. If the DC-DC boost regulation unit 304 uses the resistor R3 instead of the variable resistor VR1, the high voltage DC voltage Vo can be calculated according to Equation 1. If the DC-DC boost regulation unit 304 uses the variable resistor VR1 instead of the resistor R3, the high voltage DC voltage Vo can be calculated according to Equation 2.

The function of the DC-AC output control unit 306 is to convert the high-voltage DC voltage Vo into a high-voltage AC voltage. As shown in the third figure, the DC-AC output control unit 306 provides two sets of output voltages (Oa1, Oa2) and (Ob1, Ob2) of a and b, wherein the control signal for controlling the output voltage of the group a (Oa1, Oa2) is Ca. With Ea, the control signals for controlling the b group output voltages (Ob1, Ob2) are Cb and Eb. The high and low levels of the control signal Ca control the high voltage outputs of the output voltages Oa1 and Oa2 which are mutually inverted in the group a, and the high and low levels of the control signal Ea control the output voltages Oa1 and Oa2 which are mutually inverted in the group a. Output or not. Similarly, the high and low levels of the control signal Cb control the high voltage outputs of the output voltages Ob1 and Ob2 which are mutually inverted in the b group, and the high and low levels of the control signal Eb control the output voltages which are mutually inverted in the b group. The output of Ob1 and Ob2 or not. The high and low levels of the main control signal E simultaneously control the output of all signals. The high level of the signal is defined as the voltage level of the voltage greater than 1.5V, and the low level of the signal is defined as the voltage level of the voltage less than 0.3V. The actual output voltage of the two electrodes actually output to the piezoelectric actuator (not shown) is Oa1-Oa2 or Ob1-Ob2. Thus, the power supply of the present invention is known The supply integration circuit 300 integrates the DC-DC boost regulation unit 304 and the DC-AC output control unit 306 to form an integrated circuit instead of DC-DC boost regulation unit and DC-AC as in the prior art. The output control unit is designed to be separated into two separate circuit units.

The fourth graph (A) shows the waveforms of the control signals Ca, Cb, Ea, Eb, and the fourth graph (B) shows the waveforms of the output voltages Oa1, Ob1, Oa2, Ob2 and the actual output voltages Oa1-Oa2, Ob1-Ob2. Waveform. The fifth graph shows the waveform of the scan voltage of the actual output voltage Oa1-Oa2 or Ob1-Ob2. As can be seen from the fourth figure, the output voltages Oa1, Ob1 and the output voltage Oa2.Ob2 have the same voltage value, and the phases are opposite to each other. The waveforms of the voltages Oa1-Oa2, Ob1-Ob2 actually outputted to the piezoelectric actuators are periodically changed between Vo and -Vo as shown in the fourth (B) and fifth figures. Therefore, the waveforms of the actual output voltages Oa1 - Oa2, Ob1 - Ob2 will resemble a rectangular wave, thereby driving the pressing actuator to perform periodic vibration.

The sixth diagram shows a schematic view of the appearance of the power supply integrated control circuit 300 of the present invention applied to the piezoelectric actuator. It is to be noted that in the present specification, similar elements are denoted by the same reference numerals. As shown in the sixth figure, a piezoelectric actuator head 600 is provided for spraying ink droplets 602. The piezoelectric actuator 320 includes an ink reservoir 604 for temporarily storing ink, and a piezoelectric actuator 606 for providing periodic vibration to temporarily store ink in the ink reservoir 604 via the nozzle 608. ejection. The piezoelectric actuator head 600 further includes a power supply control integration circuit 300 for powering the piezoelectric actuator 606 for periodic motion. The circuit diagram of the power supply control integration circuit 300 is as shown in the third figure.

The seventh diagram shows a top view of the piezoelectric actuator 606. As shown in the seventh figure, the piezoelectric actuator 606 is a ring-shaped elastic piece disposed on a flexible printed circuit board 700. The piezoelectric actuator 606 receives the output voltages Oa1, Oa2 of the power supply control integration circuit 300 via the two electrodes 702, 704. The electrodes 702, 704 apply the output voltages Oa1, Oa2 to drive the piezoelectric actuator 606 for periodic vibration.

In summary, the present invention provides a power supply control integration circuit for a piezoelectric actuator, which includes a DC-DC boost regulation unit and a DC-AC output control unit, and the DC-DC boost regulation unit is used to A low voltage DC voltage is boosted to a high voltage DC voltage, and the DC-AC output control unit is coupled to the DC-DC boost regulation unit to convert the polarity of the high voltage DC voltage to an AC voltage. Since the DC-DC boost regulating unit and the DC-AC output control unit are integrated in the integrated circuit to form a single circuit unit, the number of circuit components can be reduced, the circuit design complexity can be reduced, and the coil type transformer and the power supply are not required. Increased conversion efficiency and reduced manufacturing costs.

This case has been modified by people who are familiar with the technology, but it is not intended to be protected by the scope of the patent application.

300‧‧‧Power supply control integration circuit

302‧‧‧Integrated circuit chip

304‧‧‧DC-DC boost regulator

306‧‧‧DC-AC output control unit

Claims (2)

A power supply control integrated circuit for a piezoelectric actuator, comprising: a DC-DC boost regulation unit for boosting a low-voltage DC voltage into a high-voltage DC voltage; and a DC-AC output control unit connected to The DC-DC step-up adjusting unit is configured to convert the polarity of the high-voltage DC voltage into an AC voltage, comprising: a complex array output voltage, wherein the output voltages of the groups have the same voltage value but opposite output voltages of two Driving the piezoelectric actuator; the multi-array control signal, each group of control signals respectively corresponding to a set of output voltages, and for controlling the output and output of the group of output voltages; and a main control signal for simultaneously controlling the a complex array control signal output; thereby, the DC-DC boost regulation unit and the DC-AC output control unit form an integrated circuit, wherein the DC-DC boost regulation unit is part of an integrated circuit chip and passive The circuit component is composed, and the DC-AC output control unit is composed of another part of the integrated circuit chip. The power supply control integration circuit of the piezoelectric actuator according to claim 1, wherein the main control signal of the DC-AC output control unit is used to control the generation of the complex array output voltage.