Two-Mirror Scanning System With Integrated Fold Mirror

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing scanned beam projection systems face challenges in compactness and complexity due to the need for precise control of multiple mirrors, particularly in achieving high-definition images with minimal distortion in mobile and wearable applications.

Innovation Solution

A two-mirror scanning system integrated with a fold mirror and output optic, where the fold mirror is either integrated on a scanning mirror substrate or formed on a common substrate with the scanning mirrors, allowing for a compact design and reduced distortion through the use of a wedge optic to correct image distortion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a two-mirror scanning system is used to simplify mirror control, then ease of operation is improved, but device volume increases

Engineering Contradiction:
Improvemirror control simplicityVSAvoidscanning system volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent merges the fold mirror with the output optic by integrating the fold mirror surface onto the output optic component. This integration allows the two-mirror scanning system to achieve compact configuration by combining multiple optical functions into fewer discrete components, thereby reducing overall system volume while maintaining the simplified two-mirror control architecture

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a fold mirror to change the optical path direction, effectively using spatial dimensionality to reduce the physical footprint of the scanning system. By folding the light path at an angle rather than allowing it to continue in a straight line, the system achieves compact packaging while maintaining the two-mirror scanning functionality

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of operation

If a two-mirror scanning system is used to simplify mirror control, then ease of operation is improved, but image distortion increases

Engineering Contradiction:
Improvemirror control simplicityVSAvoidimage distortion
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent introduces a wedge optic as an intermediary element between the scanning mirrors and the output. This wedge optic acts as a distortion correction medium that compensates for the inherent geometric distortion introduced by the two-mirror scanning configuration, thereby improving image quality while maintaining the simplicity of the mirror control system

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes a wedge optic with specific angular parameters to correct distortion. By carefully selecting the wedge angle and positioning, the system compensates for scanning-induced distortion through optical parameter adjustment, achieving high-definition images with minimal distortion while keeping the mirror control simple

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If mirrors are arranged around a complex polygonal support structure, then structural stability is improved, but device complexity increases

Engineering Contradiction:
Improvemirror arrangement stabilityVSAvoidsupport structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent integrates the fold mirror function directly into the output optic component, eliminating the need for a separate complex polygonal support structure. This merging of functions reduces the number of discrete components and simplifies the overall structure while maintaining the stability required for precise mirror arrangement

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The output optic is designed to serve multiple functions: it acts as both the output optical element and the fold mirror. This multi-functionality eliminates the need for dedicated support structures for the fold mirror, thereby reducing device complexity while maintaining structural stability for the mirror arrangement

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enables the creation of high-definition images while maintaining a compact form factor, reducing the overall volume of the scanning system and minimizing image distortion, such as keystone or smile distortion, to less than 5%.

Implementation Method 1

a fold mirror integrated with an output optic... where the fold mirror is either integrated on a scanning mirror substrate or formed on a common substrate with the scanning mirrors

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

reducing the overall volume of the scanning system and minimizing image distortion, such as keystone or smile distortion, to less than 5%

Methodology Applied
Scientific EffectRefraction: Refraction

Data Source

PatentEP2411859B1Two-mirror scanning system
Publication Date: 2020.04.22 MICROVISION INC
  • EP2411859B1 patent drawingFigure 1~2
  • EP2411859B1 patent drawingFigure 3~5
  • EP2411859B1 patent drawingFigure 6

AI summary

A scanning beam projection system includes a two-mirror scanning system (110). One mirror scans in one direction, and a second mirror scans in a second direction. A fast scan mirror (320) receives a modulated light beam from a fold mirror (312) and directs the modulated light beam to a slow can mirror. The fold mirror may be formed on an output optic or may be formed on a common substrate with the slow scan mirror.