Optical Deflector With Segmented Piezoelectric Actuators
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Solution Overview
Problem
Existing one-dimensional optical deflectors face limitations in increasing drive power and reliability due to inefficient voltage distribution and piezoelectric actuator configurations, which restrict the rocking angle of the mirror and lead to power consumption issues and deterioration of piezoelectric components.
Innovation Solution
The optical deflector design incorporates semi-circular piezoelectric actuators with strategically placed slits, determined by polarization polarity distribution, to optimize voltage application and reduce power consumption, allowing for increased rocking angles with lower drive voltage amplitudes, thus enhancing reliability and reducing piezoelectric material degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the rocking angle of the mirror is increased by applying higher drive voltage amplitudes to the piezoelectric actuators, then the optical deflection performance is improved, but the power consumption increases and the piezoelectric components deteriorate faster
Solution Approach 1:
The piezoelectric actuators are divided into multiple independent piezoelectric portions with different polarization polarities. Each portion can be controlled independently with optimized voltage amplitudes, allowing the system to achieve the required rocking angle while minimizing total power consumption and reducing stress on individual piezoelectric components.
2Speed
If the piezoelectric actuators are configured with uniform polarization polarity, then the structure is simple, but the voltage distribution is inefficient and the rocking angle is limited
Solution Approach 1:
Different portions of the piezoelectric actuators are assigned different polarization polarities according to the local vibration amplitude distribution. This creates a non-uniform configuration where each region's polarization matches its functional requirements, optimizing voltage distribution and maximizing the rocking angle while maintaining structural integrity.
3Speed
If higher drive voltage amplitudes are applied to achieve larger rocking angles, then the optical deflection capability is enhanced, but the reliability of piezoelectric components decreases due to accelerated deterioration
Solution Approach 1:
By segmenting the piezoelectric actuators into multiple portions with different polarities, the system can achieve the required rocking angle through coordinated action of multiple segments rather than overdriving a single segment. This distributes the mechanical stress and electrical load, reducing deterioration and improving reliability.
Solution Approach 2:
The invention changes the polarization polarity parameter of different piezoelectric portions to match the vibration amplitude distribution. This parameter optimization allows the system to operate at lower voltage amplitudes for the same rocking angle, reducing electrical stress and improving component reliability.
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
The design achieves a larger rocking angle of the mirror with reduced drive voltage amplitudes, decreasing power consumption and improving the reliability and longevity of the piezoelectric components, while maintaining effective rocking motion.
Implementation Method 1
a pair of semi-circular piezoelectric actuators 3-1 and 3-2 opposite to each other with respect to the mirror 1 each coupled to both of the torsion bars 2a and 2b for rocking the mirror 1 around the Y-axis
Implementation Method 2
a circular mirror 1... a light beam BM transmitted from a light source 1701 is reflected by the mirror 1
Implementation Method 3
a pair of torsion bars 2a and 2b oppositely arranged along a Y-axis (rocking axis) each having an end coupled to the circumference of the mirror 1
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
In an optical deflector including a mirror (1), a frame (4, 4'), first and second torsion bars (2a, 2b, 2'a, 2'b), first and second piezoelectric actuators (3'-1, 3'-2, 3"-1, 3"-2) coupled to both of the first and second torsion bars (2a, 2b, 2'a, 2'b), and first and second coupling bars (5-1, 5-2), each of the first and second piezoelectric actuators (3'-1, 3'-2, 3"-1, 3"-2) is divided into first, second and third areas (G1, G2) in accordance with a polarization polarity distribution obtained by performing a predetermined simulation upon the optical deflector where piezoelectric portions with no slits are hypothetically provided in the first and second piezoelectric actuators (3'-1, 3'-2, 3"-1, 3"-2) while a predetermined rocking operation is performed upon the mirror (1). First piezoelectric portions (3'-11, 3'-13, 3"-11, 3"-13) are formed in the first and third areas of the first piezoelectric actuator (3'-1, 3"-1), and second piezoelectric portions (3'-21, 3'-23, 3"-21, 3"-23) are formed in the first and third areas of said second piezoelectric actuator (3'-2, 3"-2). A first drive voltage (VY1) applied to the first piezoelectric portions is opposite in phase to a second drive voltage (VY2) applied to the second piezoelectric portions.