I/O Separator for Laser Projector Light Path Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional laser projectors with scanning mirrors face challenges in minimizing the size of the laser projector system due to the need to separate the input and output light paths, which increases the optical path length and reduces the effective beam size and system resolution.
Innovation Solution
The use of an input/output (I/O) separator, which can include prisms, polarization beam splitters (PBS), and quarter wave plates (QWP), to separate the input and output light paths from the scanning mirror, allowing for a more compact design by minimizing the angle between the input and output paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional scanning mirrors are used with separated input and output light paths, then the scanning function is achieved, but the optical path length increases and the effective beam size is reduced
Solution Approach 1:
An I/O separator is introduced as an intermediary optical element between the scanning mirror and the output beam path. This separator uses polarization beam splitting and wave plate technology to redirect the output beam without requiring a long physical separation distance, thus resolving the contradiction between achieving scanning function and minimizing optical path length.
2Ease of operation
If the angle between input and output light paths is increased to separate the paths, then the separation is improved, but the effective beam size and system resolution are reduced
Solution Approach 1:
The I/O separator acts as a mediator that achieves light path separation through polarization optics rather than large angular separation. By using polarization beam splitting, the system can separate input and output paths with minimal angular deviation, preserving beam size and resolution while achieving effective separation.
Solution Approach 2:
The patent changes the parameter of light polarization state to achieve separation. By manipulating polarization angles and using wave plates to rotate polarization states, the system achieves clean separation of input and output paths without increasing the physical angle between paths, thus maintaining beam quality and resolution.
3Manufacturing precision
If a larger aperture mirror is used to maintain beam size, then the resolution is improved, but the electrical power consumption increases
Solution Approach 1:
The I/O separator serves as a mediator that enables the use of a smaller aperture mirror while maintaining the required beam size and resolution. By optimizing the optical path geometry through polarization splitting, the system achieves effective beam delivery without requiring a larger mirror aperture, thus reducing the electrical power consumption of the scanning mirror actuator.
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 solution enables a more compact laser projector system while maintaining the brightness and resolution of the projected image, as the full aperture of the scanning mirror can be utilized, and the system can operate with a smaller aperture mirror, reducing electrical power consumption.
Implementation Method 1
The I/O separator is configured to reflect the input light path using total internal reflection while transmitting the output light path
Implementation Method 2
The I/O separator may include a polarization beam splitter (PBS) and a quarter wave plate (QWP) disposed in the light path
Data Source
AI summary
Systems and methods of separating the input light path from the output light path of a scanning mirror in a laser projector system while keeping the overall footprint of the laser projector system to a minimum. The system includes a scanning mirror, an optical engine, and an input/output (I/O) separator disposed between the optical engine and the scanning mirror to direct light from the optical engine towards the scanning mirror along an input path and to direct light reflected from the scanning mirror along an output path. The I/O separator, disposed to intersect both the input and output paths, can be implemented as a prism or a combination of a polarizing beam splitter and a quarter wave plate.