Adjustable Diffractive Optical Element for Depth Sensing Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional depth sensing methods in head-mounted displays (HMDs) face limitations in real-time scanning speed, mechanical stability, and dynamic resolution adjustment, particularly with mechanical scanners and fixed structured light patterns, which are inadequate for dynamic depth sensing applications.
Innovation Solution
A depth camera assembly (DCA) with a structured light generator, diffractive optical element (DOE), and controller that dynamically adjusts the structured light pattern by varying the position of the DOE, allowing for adjustable resolution and steerable illumination patterns, integrated into HMDs for enhanced depth sensing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a mechanical scanner is used for depth sensing, then the scanning coverage can be adjusted, but the scanning speed is insufficient and mechanical stability is poor
Solution Approach 1:
The patent replaces the mechanical scanner with a diffractive optical element (DOE) that uses optical diffraction to generate scanning patterns. The DOE creates multiple diffracted beams that scan the field of view simultaneously without moving parts, achieving high scanning speed while maintaining the ability to adjust scanning coverage by changing DOE parameters or positions.
Solution Approach 2:
The patent implements dynamic adjustment of the structured light pattern by moving the DOE to different positions along the optical axis. This dynamic repositioning allows real-time modification of the diffraction pattern and scanning coverage without mechanical scanning components, resolving the contradiction between adaptability and speed.
2Adaptability or versatility
If a mechanical scanner is used for depth sensing, then the scanning coverage can be adjusted, but mechanical stability is poor
Solution Approach 1:
The patent eliminates mechanical scanning components by using a stationary DOE that generates scanning patterns through optical diffraction. This substitution removes mechanical instability issues while preserving the ability to adjust scanning coverage through optical means such as DOE repositioning or parameter changes.
3Device complexity
If a fixed structured light pattern is used, then the system is simple, but dynamic resolution adjustment is not possible
Solution Approach 1:
The patent introduces dynamic adjustability by enabling the DOE to be repositioned along the optical axis. This movement changes the diffraction pattern and spatial resolution of the structured light in real time, allowing the system to adapt to different depth sensing requirements while maintaining relative simplicity through the use of a single adjustable optical element.
Solution Approach 2:
The patent achieves dynamic resolution adjustment by changing the position parameter of the DOE relative to the light source. This parameter change modifies the diffraction pattern characteristics, enabling flexible control over spatial resolution and scanning coverage without complicating the overall system architecture.
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
Enables real-time, dynamically adjustable depth sensing with improved scanning speed and stability, accommodating various applications such as near sensing, far sensing, and object tracking, by altering the DOE's position to modify the structured light pattern and field-of-view.
Implementation Method 1
The DOE is mounted on the mounting element and generates diffracted scanning beams from the one or more pulses of light
Data Source
AI summary
A depth camera assembly for depth sensing of a local area includes a structured light generator, an imaging device, and a controller. The structured light generator illuminates a local area with structured light and includes an illumination source, a mounting element, and a diffractive optical element (DOE) mounted on the mounting element. The mounting element can have a plurality of adjustable positions relative to the illumination source based on emission instructions from the controller. The DOE generates, using light emitted from the illumination source, diffracted scanning beams that are projected as the structured light into the local area. A pattern of the structured light is dynamically adjustable and unique for each adjustable position of the mounting element. The imaging device captures image(s) of the structured light reflected from object(s) in the local area. The controller determines depth information for the object(s) based in part on the captured image(s).