Piezoelectric Actuator for Laser Beam Intensity Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current laser beam intensity control systems face limitations in accuracy and dynamic characteristics due to the inherent inaccuracies of electromechanical and piezoelectric actuators, which affect the precision and efficiency of laser beam intensity control during manufacturing processes.
Innovation Solution
A piezoelectric actuator system comprising a thin-walled annular elastic disc with elongated slots and a concentric cylinder, combined with bimorph piezoelectric elements, allows for high-precision rotational motion of the beam intensity control element using asymmetrical electric signals and DC signals, enhancing resolution and rotational speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromechanical actuators or sliding electromechanical actuators are used to control beam intensity, then the system can achieve basic intensity control, but the accuracy of displacement and resolution are limited
Solution Approach 1:
The patent replaces traditional electromechanical actuators with a piezoelectric actuator that uses piezoelectric ceramic elements to generate precise mechanical displacement through electrical signals. This substitution eliminates the inherent inaccuracies of electromechanical systems while achieving sub-micrometer resolution in controlling the rotational position of the beam intensity control element
Solution Approach 2:
The patent employs asymmetric electric signals with controlled amplitude and frequency to the piezoelectric elements, enabling precise control of the actuator's mechanical response. By varying electrical parameters (voltage amplitude, frequency, asymmetry ratio), the system achieves accurate control of the beam intensity control element's rotational position without mechanical backlash or wear
2Measurement precision
If piezoelectric actuators with console-mounted configuration are used, then precision sliding motion can be achieved in two directions, but the resolution of step motion is significantly worse and the element degrades dynamic characteristics
Solution Approach 1:
The patent designs the piezoelectric actuator with a lightweight, flexible structure consisting of a thin-walled annular elastic disk with piezoelectric elements mounted on both sides. This dynamic structure responds rapidly to electrical signals while maintaining high positioning accuracy, achieving both precision and fast response without the sluggishness of console-mounted actuators
Solution Approach 2:
The patent uses asymmetric electric signals applied to the piezoelectric elements to generate controlled rotational motion. The asymmetry in the electrical excitation pattern produces unbalanced forces that drive the beam intensity control element through precise angular displacements, enabling high-resolution control while maintaining dynamic performance
3Manufacturing precision
If higher resolution is achieved through precision actuators, then beam intensity control accuracy improves, but the angular displacement range and rotational speed are limited
Solution Approach 1:
The patent employs periodic asymmetric electric signals with controlled frequency to drive the piezoelectric actuator. By adjusting the frequency and duty cycle of these periodic signals, the system achieves both high-resolution positioning and unlimited angular displacement, as the piezoelectric elements can be continuously repositioned through repeated cycles of electrical excitation
Solution Approach 2:
The patent designs the beam intensity control element to perform multiple functions: it controls beam intensity through precise rotational positioning while also enabling unlimited angular displacement and high-speed operation. The piezoelectric actuator structure itself serves both as a positioning mechanism and a dynamic response element, eliminating the need for separate components
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 system achieves improved accuracy and dynamic characteristics, enabling precise and efficient control of laser beam intensity with unlimited angular displacement and high resolution, suitable for applications like Direct Metal Laser Sintering.
Implementation Method 1
a piezoelectric actuator consisting of a thin-walled annular elastic disc having the inner flat surface perforated with elongated slots, directed at an acute angle to the constituent of a thin-walled cylinder, which is resiliently attached to the inner surface of the disc at one end
Data Source
Figure 1a~1b
Figure 1c~2
Figure 3~5
AI summary
An optical beam intensity control system with advanced accuracy, dynamic characteristics and extended functionality includes a piezoelectric actuator (3) rotating a light intensity changing element (5), a light intensity sensor (25), and a controller/generator (10). The actuator (3) comprises two piezoelectric rings (11) glued to an elastic ring-shaped disk (7) with an inner surface perforated by elongated slots (8) directed at an acute angle to the surface of a cylinder (6). A rotor (4) carrying the light intensity changing element is resiliently pressed against the outer surface of the cylinder. The piezoelectric deforms the disc in the radial direction, and torsional vibration is excited in the cylinder via the slots. Functionality is extended by adjusting the intensity of the beam (1) through an optical lens (21) attached to an outer part of the disc which is able to move together with the lens along the optical axis (24) when symmetrical bending deformations are generated in the disk along the optical axis.