Switchable Fringe Pattern Illuminator for Compact Depth Sensing
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Solution Overview
Problem
Traditional fringe pattern illumination devices for artificial reality systems are large, heavy, power-intensive, and offer limited field of view and fixed fringe spacing, making them unsuitable for compact and dynamically adjustable applications.
Innovation Solution
A compact light projection system with switchable fringe pattern illuminators that incorporate phase delay devices, coupling controllers, and switchable light sources, allowing for dynamic adjustment of fringe patterns and field of view, enabling flexible interferometric illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional fringe pattern illumination devices are used, then fringe pattern generation is achieved, but the device size is large and weight is heavy
Solution Approach 1:
The patent combines multiple optical components (laser source, modulator, beam splitter, mirrors, and projection optics) into an integrated fringe pattern illumination device. This merging of previously separate components enables compact size while maintaining the full fringe pattern generation capability through coordinated operation of the integrated elements.
Solution Approach 2:
The patent employs a nested arrangement where optical components are positioned within each other's spatial envelopes. The laser source, modulator, and optical paths are configured in a compact nested geometry that minimizes overall device volume while preserving the interferometric fringe generation function.
2Use of energy by moving object
If traditional fringe pattern illumination devices are used, then fringe pattern generation is achieved, but power consumption is significant
Solution Approach 1:
The patent employs periodic modulation of the laser source at specific frequencies to generate the fringe patterns. This periodic action replaces continuous high-power illumination with pulsed or modulated light delivery, significantly reducing average power consumption while maintaining the interferometric measurement capability through timing-synchronized detection.
3Adaptability or versatility
If traditional fringe pattern illumination devices are used, then fixed fringe spacing is provided, but dynamic adjustability is limited
Solution Approach 1:
The patent incorporates adjustable optical elements including variable spacing between mirrors, tunable beam splitters, and reconfigurable optical paths that enable dynamic adjustment of fringe spacing. These dynamic components allow the system to adapt fringe patterns to different measurement requirements without requiring multiple fixed devices.
Solution Approach 2:
The patent enables continuous variation of key optical parameters including fringe spacing, wavelength, and illumination angle through mechanically adjustable components and controllable optical elements. This parameter tunability provides versatility for different applications while the modular design keeps system complexity manageable.
4Area of stationary object
If traditional fringe pattern illumination devices are used, then illumination is provided, but field of view is limited
Solution Approach 1:
The patent extends the field of view by introducing additional optical dimensions including multiple beam paths, angled projections, and three-dimensional optical routing. This multi-dimensional light distribution approach expands coverage area without proportionally increasing device footprint or excessive complexity.
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
The solution provides a compact, power-efficient, and dynamically adjustable fringe pattern illumination system with a larger field of view and multiple fringe spacings, enhancing depth sensing and object tracking capabilities in artificial reality systems.
Implementation Method 1
an optical path switch configured to receive light and dynamically control an amount of light that is provided to a first waveguide and an amount of light that is provided to a second waveguide
Implementation Method 2
The switchable fringe pattern illuminators described herein provide flexibility by incorporating dynamically adjustable components, such as phase delay devices, coupling controllers, and switchable light sources, which may each be adjusted to control the resulting fringe pattern of interferometric illumination.
Implementation Method 3
The switchable fringe pattern illuminators described herein provide flexibility by incorporating dynamically adjustable components, such as phase delay devices, coupling controllers, and switchable light sources, which may each be adjusted to control the resulting fringe pattern of interferometric illumination.
Data Source
AI summary
A switchable fringe pattern illuminator includes an optical path switch configured to receive light and dynamically control an amount of light that is provided to a first waveguide and an amount of light that is provided to a second waveguide. A first projector configured to generate a first fringe pattern using light from the first waveguide. The first fringe pattern illuminates a first portion of a target area. A second projector configured to generate a second fringe pattern using light from the second waveguide. The second fringe pattern illuminates a second portion of a target area. The illuminator may be part of a depth camera assembly (DCA). The DCA is configured to capture images of a portion of the target area. The DCA is further configured to determine depth information for an object in the target area based in part on the captured images.