Optical Switch Adjusts Laser Field of View
Solution Overview
Problem
Conventional display systems using scanning laser projectors are inefficient in terms of power and time consumption when projecting images within a subset of the total achievable field of view, as they require scanning over the entire area even when only a portion is needed.
Innovation Solution
The use of optical switches to selectively control the angle of incoming laser light incident on a scan mirror, allowing the system to change the region of the field of view for image projection without requiring the scan mirrors to cover the entire display area, thereby reducing power consumption and improving scanning speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the scan mirrors cover the entire display area, then the field of view is maximized, but the power consumption and scanning time increase
Solution Approach 1:
The field of view is divided into multiple selectable regions (e.g., upper half, lower half, left half, right half). Instead of scanning the entire display area, the system segments the FOV and activates only the necessary segment, reducing the scanning range and power consumption while maintaining adequate coverage for the current display task.
Solution Approach 2:
The system dynamically adjusts the scanning range based on the actual display requirements. By detecting which region of the FOV is needed and configuring the scan mirrors to cover only that region, the system adapts its operational parameters to minimize energy consumption while preserving the necessary field of view coverage.
2Adaptability or versatility
If the scan mirrors cover the entire display area, then the field of view is maximized, but the scanning speed decreases
Solution Approach 1:
The scanning system is divided into multiple independent scanning regions. By segmenting the FOV and scanning only the required segment, the system reduces the total scanning distance and time, thereby increasing scanning speed while maintaining sufficient field of view coverage for the current task.
Solution Approach 2:
The scanning speed is dynamically optimized by adjusting the scanning range according to display needs. When only a portion of the FOV is required, the scan mirrors operate over a reduced range, enabling faster scanning and improving the overall system response time.
3Reliability
If the system scans over the entire area, then complete coverage is achieved, but time consumption increases
Solution Approach 1:
The display area is segmented into multiple regions, and the system selectively scans only the regions where images need to be projected. This segmentation approach ensures that coverage is complete for the necessary areas while eliminating wasted scanning time in unused regions, thus reducing overall time consumption.
Solution Approach 2:
Instead of performing full-area scanning (excessive action), the system performs partial scanning only in the required regions. This partial action approach maintains reliability by ensuring complete coverage of necessary areas while significantly reducing the time spent on unnecessary scanning operations.
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 approach enhances power and time efficiency by allowing the system to project images only in the required region of the field of view, reducing unnecessary scanning and energy usage.
Implementation Method 1
optical switches that redirect incoming light onto a scan mirror at different angles
Data Source
AI summary
Display systems, such as near eye display systems or wearable heads up displays, may include a laser projector having an optical switch assembly disposed an at input to an optical scanner of the laser projector. The optical switch assembly includes at least one optical switch, and a controller selectively modifies the orientation of each optical switch to selectively change an angle at which laser light is directed onto a scan mirror of the optical scanner. Changing this angle shifts the scan region over which the scan mirror scans the laser light and, relatedly, shifts a region of a field of view of the display. In some embodiments, the controller is configured to modify the optical switch orientation(s) to correct non-idealities in the angle of the laser light.