Two-Axis Scanning Mirror With Electrostatic And Piezoelectric Drivers

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Solution Overview

Problem

Conventional LiDAR systems using two one-axis mirrors and a galvanometer to achieve two-axis scanning face challenges in form factor reduction, cost, and mechanical reliability, particularly due to the large size and mechanical issues associated with the galvanometer.

Innovation Solution

A scanner configuration that includes a scanning mirror independently rotatable around two axes, driven by a first electrostatic driver for high-frequency rotation around one axis and a second piezoelectric driver for low-frequency rotation around the other axis, eliminating the need for a galvanometer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a galvanometer is used to drive the slow-sweep axis of the scanning mirror, then the scanning system can achieve two-axis rotation, but the system occupies a disproportionately large area and has mechanical reliability issues

Engineering Contradiction:

Improvemechanical reliabilityVSAvoidsystem area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent replaces the galvanometer (a mechanical actuator with moving parts) with an electrostatic actuator that uses electrostatic forces to drive the scanning mirror. This substitution eliminates the mechanical components that caused reliability issues and reduced the system area, as electrostatic actuators have no moving parts and can be miniaturized more effectively.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the galvanometer from the system entirely, replacing it with a different actuation mechanism. By taking out the problematic component (galvanometer) and substituting it with an electrostatic actuator, the system achieves both reduced area and improved reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If two separate one-axis scanning mirrors are used to implement two-axis scanning, then the scanning function is achieved, but the form factor is increased due to the space required for two mirrors and light paths

Engineering Contradiction:

Improvetwo-axis scanning capabilityVSAvoidsystem volume

Core Design Contradiction:

Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent merges two separate one-axis scanning mirrors into a single two-axis scanning mirror. This single mirror can rotate about two different axes simultaneously, eliminating the need for two separate mirrors and their associated light paths, thereby reducing the system volume while maintaining the two-axis scanning capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single scanning mirror is designed to perform multiple functions: it can scan in two different axes and operate at two different frequencies (fast-sweep and slow-sweep). This multi-functional design replaces what previously required two separate mirrors, reducing the overall system volume.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If a galvanometer is used for slow-sweep scanning, then the scanning function is achieved, but the cost increases due to the expensive nature of galvanometers

Engineering Contradiction:

Improvescanning functionVSAvoidsystem cost

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The patent replaces the expensive galvanometer with a cost-effective electrostatic actuator. Electrostatic actuators can be manufactured using standard semiconductor fabrication processes, making them significantly cheaper than galvanometers while maintaining the required scanning functionality.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent substitutes the mechanical galvanometer system with an electrostatic actuation system, which is not only cheaper to manufacture but also more reliable and smaller in size. This substitution addresses both the cost issue and the form factor constraint.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 configuration allows for significant reductions in form factor and cost while maintaining accurate two-axis scanning, essential for applications like autonomous driving and high-definition map surveys.

Implementation Method 1

a first driver (e.g., electrostatic) configured to drive the scanning mirror to rotate around the first axis

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

a second driver (e.g., piezoelectric) configured to drive the scanning mirror to simultaneously rotate around the second axis

Methodology Applied

Scientific EffectPiezoelectric force: Piezoelectric Effect

Data Source

PatentUS12306399B2System and method for driving a two-axis scanning mirror using drivers of different types

Publication Date: 2025.05.20 BEIJING VOYAGER TECH CO LTD

AI summary

Embodiments of the disclosure provide a scanner for steering optical beams. In certain configurations, the scanner may include a scanning mirror independently rotatable around a first axis and a second axis. In certain other configurations, the scanner may also include a first driver configured to drive the scanning mirror to rotate around the first axis. In still other configurations, the scanner may further include a second driver configured to drive the scanning mirror to simultaneously rotate around the second axis. In certain aspects, the first driver and the second driver may be different types of drivers.