SU1659959A1 - Piezoceramic deflector - Google Patents

Abstract

The invention relates to instrument making and is intended for scanning a light beam as a part of optical communication equipment. The device contains the deflector itself, consisting of two connected piezoceramic plates, and a control device consisting of a resistor, two diodes, a Schmittz trigger, an inverter, a generator, a counter, a computer, and a motion control unit. When the deflector operates, by monitoring the feedback signal on a resistor, the control voltage is corrected, and thus the linearity of the deflector operation is increased while the hysteresis effect decreases. 2 sludge.

Description

The invention relates to instrument making and is intended for scanning a light beam comprising optical communication equipment, location, control systems, and the like.

The purpose of the invention is to improve the accuracy by linearizing the dependence of the angle of deviation of the piezoelectric element on the magnitude of the supply voltage by reducing the hysteresis of the amplitude characteristic of the deflector.

Figure 1 shows the structural diagram of the piezoceramic deflector; Fig. 2 illustrates voltage pulse shapes on resistor R.

The deflector contains a piezoceramic cell 1 with a mirror 2 fixed on it, an inverting amplifier 3, a Schmitt trigger 4, element 5, a generator of 6 clock pulses, a counter 7, a microcomputer 8. a control signal source 9.

The piezoceramic cell 1 consists of two piezoceramic plates 10, an internal conductive element 11. external conductive electrodes 12 and 13. In addition, the device contains diodes

UD1 14 and UD 15 and resistor R 16 connected at one end to the common lead, and the other to internal conductive electrode 11 of piezoceramic elements, to the anode UD 1 14 and to the cathode UD2 15 diodes, the anode of which is connected to the input of inverting amplifier 3, the output of which is connected to the cathode of the first diode UD 14 and to the input of the Schmitt trigger 4, the output of which is connected to one of the inputs of the element 5, the second input of which is connected to the generator 6 of clock pulses, and the output to the information input of the counter 7, the reset input in O which is connected to the reset bus ikro- computer 8, wherein the source control signal 9 is made kodoreguliruemym having an input connected to the output of the microcomputer 8, and The output to external conductive electrodes of the piezoceramic elements 12, 13.

The device works as follows.

If voltage is applied to the bimorph element in a jump-like manner, U, then its free end moves, at which mirror 2 is fixed.

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When a bimorph piezoelectric element 1 moves on a resistor 16 connected in series with it, a voltage pulse occurs (Fig. 2a). If now the voltage U is removed from the bimorph element 1, then it will move in the opposite direction, and the reverse polarity voltage appears on the resistor 16 (fig. 2b). By comparing these voltages, it can be concluded that the pulse duration at the base is different when the bimorph piezoelectric element 1 moves in the forward and reverse directions, which allows introducing a correction for the movement of the end of the bimorph piezoelectric element and eliminating the hysteresis. For this, the pulse duration is converted into a code that is recorded in the memory of microcomputer 8. Microcomputer 8 compares two codes (a code proportional to the pulse duration with increasing voltage, and a code proportional to the decrease in voltage on the bimorph piezoelectric cell) and through the control voltage source 9, the supply voltage of the bimorph piezoelectric element 1 changes until the code at the output of the counter 7, proportional to the voltage Y, becomes equal to the code proportional to the voltage rise and stored in memory the microcomputer 8.

The conversion of the pulse duration into a code is as follows.

When a bimorph piezoelement 1 moves on a resistor 16, a voltage pulse arises. This pulse arrives through the first diode UD 1 14 to the input of a Schmitt trigger 4, the output of which forms a single impulse arriving at one of the inputs I 5, the second input of which connected to a generator of 6 clock pulses. At the output of the circuit 5, a sequence of pulses is received at the input of counter 7, which transforms them into a code transmitted to the memory of the microcomputer 8.

If the voltage is now removed from the bimorph piezoelectric element 1, it will move in the opposite direction, and a reverse polarity voltage will occur on the resistor 16, which is fed to the Schmitt trigger input 4 through the second diode UD2 15 and the inverting amplifier 3.

The process of converting the duration of the pulses appearing on the resistor 16 when the bimorph piezoelectric element 1 moves in the opposite direction is similar.

Thus, the proposed device allows monitoring the pulse duration on the base during the movement of the bimorph piezoelectric element in the forward and reverse directions and, in case of divergence, correct the movement of the piezoelectric element until the error of amplitude response is completely eliminated.

Claims (1)

Invention Formula A piezoceramic deflector containing a piezoceramic element made in the form of two connected piezoceramic plates with coinciding directions of the polarization vectors and an internal conductive electrode between the plates, on the outer sides of which are conductive electrodes interconnected to which the output of the control signal source is connected , characterized in that in order to increase accuracy by linearizing the dependence of the angle of deviation of the piezoelement on the magnitude of the supply voltage for t reduce the hysteresis of the amplitude characteristic of the deflector, the first and second diodes, an inverting amplifier, Schmitt trigger, element I, clock generator, counter, microcomputer, resistor connected to the common end of the internal electrode and the other to the internal electrode of the piezoceramic elements to the anode of the first and the cathode of the second diode, the anode of the latter is connected to the input of an inverting amplifier, the output of which is connected to the cathode of the first diode and to the input of a Schmitt trigger. the output of which is connected to one of the inputs of the element I, the other input of which is connected to the clock pulse generator, and the output to the information input of the counter, the reset input of O which is connected to the reset bus of the microcomputer, and the output to the inverting input of the microcomputer, and the control source The signal input is connected to the output of the microcomputer. U ABOUT and Editor M.Kelemes Compiled by G. Melnikov Tehred M. Morgental Fim .2 Corrector S.Cherni