Piezoelectric Reflector Control Unit for Optical Scanning
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Solution Overview
Problem
Piezoelectric constant values vary with drive voltage, leading to non-proportional deformation of piezoelectric elements and inconsistent movement speed of reflectors in optical deflection systems, affecting the quality of optical scanning and image projection.
Innovation Solution
A control unit adjusts the drive voltage waveform to maintain a minimum value greater than zero, optimizing the voltage range to ensure proportional deformation and constant movement speed by controlling the piezoelectric constant change rate, thereby enhancing the consistency of reflector movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a voltage is applied to a piezoelectric element to deform the piezoelectric element and move the reflector, then the reflector can be driven for optical scanning, but the piezoelectric constant value varies depending on the drive voltage values, causing non-proportional deformation and inconsistent movement speed
Solution Approach 1:
The control unit preliminarily determines a drive voltage waveform whose minimum value is greater than zero before applying it to the piezoelectric element. This preliminary action ensures that the piezoelectric element operates within a voltage range where the piezoelectric constant is more stable, thereby achieving proportional deformation and consistent reflector movement speed throughout the scanning cycle
Solution Approach 2:
The invention changes the parameter of drive voltage by setting its minimum value greater than zero, rather than allowing it to reach zero or negative values. This parameter modification keeps the piezoelectric element operating in a region where the piezoelectric constant varies less, ensuring more uniform deformation and reflector speed during optical scanning
2Force
If the drive voltage minimum value is set to zero or negative, then the voltage range is maximized for actuation, but the piezoelectric constant changes greatly causing non-proportional deformation
Solution Approach 1:
The control unit modifies the drive voltage parameter by establishing a minimum value greater than zero. This parameter change restricts the voltage to a range where the piezoelectric constant remains relatively stable, ensuring that the deformation of the piezoelectric element remains proportional to the applied voltage while still providing sufficient actuation force for reflector movement
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach stabilizes the movement speed of reflectors, reducing image distortion and luminance fluctuations, and improving the overall quality of optical scanning and image projection.
Implementation Method 1
a voltage is applied to a piezoelectric element to deform the piezoelectric element and to move the reflector by the deformed piezoelectric element
Data Source
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AI summary
A control unit (11) to control a movement of a reflector (14) includes a drive signal output unit (31) to apply a drive voltage having a minimum value and a maximum value in one cycle to a piezoelectric element (202) to deform the piezoelectric element (202), the deformation of the piezoelectric element (202) causing the reflector (14) to move, and a controller (30) to control the drive voltage to have the minimum value greater than a zero voltage by a given difference value.