Two-Zone VCSEL Dot Projector with Tiling DOE
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing structured light emitters, such as dot projectors, face challenges in achieving a high fill factor without reducing the optical aperture size, which limits the resolution and available power for structured light projection.
Innovation Solution
The use of a two-zone vertical cavity surface emitting laser (VCSEL) with a single-element collimating lens and a tiling diffractive optical element (DOE) allows for the projection of multiple emission zones as structured light dots, enabling increased dot density while maintaining a fill factor below a threshold, thereby improving sensing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the optical aperture size is reduced to achieve a high fill factor, then the fill factor is improved, but the resolution and available power for structured light projection deteriorate
Solution Approach 1:
The VCSEL emitter is divided into multiple emission zones (first emission zone, second emission zone, etc.), each capable of emitting structured light independently. This segmentation allows the system to project multiple sets of dots simultaneously, increasing the total number of dots projected while maintaining a low fill factor, thereby resolving the contradiction between fill factor and resolution.
Solution Approach 2:
The patent introduces a vertical dimension by stacking multiple emission zones along the optical axis of the VCSEL. This multi-zone vertical configuration enables the system to project dots in multiple layers, effectively increasing the total dot count and resolution without increasing the lateral fill factor, thus resolving the contradiction.
2Quantity of substance
If the optical aperture size is reduced to achieve a high fill factor, then the fill factor is improved, but the available power for structured light projection deteriorates
Solution Approach 1:
The VCSEL is segmented into multiple emission zones that can operate simultaneously or independently. By distributing the power across multiple zones and projecting multiple sets of dots, the system achieves high total dot count with low fill factor while maintaining sufficient power per dot, resolving the contradiction between fill factor and available power.
Solution Approach 2:
The multiple emission zones enable continuous structured light projection across different vertical layers, maximizing the utilization of available power throughout the projection volume. This continuous multi-zone operation ensures that power is efficiently distributed to maintain dot visibility and sensing capability while keeping the fill factor low.
3Quantity of substance
If multiple emission zones are projected using a single VCSEL, then the quantity of dots is improved, but the device complexity increases
Solution Approach 1:
A single VCSEL device is designed to perform multiple functions by incorporating multiple emission zones within its structure. This multi-functional VCSEL can project multiple sets of dots from different vertical zones, effectively increasing the quantity of dots without requiring multiple separate VCSEL devices, thereby resolving the contradiction between quantity of dots and device complexity.
Solution Approach 2:
The patent merges multiple emission zones into a single VCSEL device, combining what would traditionally require multiple separate components into one integrated structure. This merging approach increases the total dot count while minimizing the increase in device complexity, as the multiple zones share common structural and control elements.
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 projection of a high quantity of dots with a fill factor of less than 10% or 5%, enhancing sensing applications like gesture recognition and three-dimensional sensing without reducing the optical aperture size, thus increasing available power and reducing aberrations.
Implementation Method 1
a two-zone vertical cavity surface emitting laser (VCSEL) with a set of emission zones configured to emit structured light forming a set of dots
Implementation Method 2
a single-element collimating lens aligned to the two-zone VCSEL
Implementation Method 3
a tiling diffractive optical element (DOE) aligned to the single-element collimating lens, wherein the tiling DOE comprises a set of tile segments aligned to the set of emission zones
Data Source
AI summary
In some implementations, an optical device includes a two-zone vertical cavity surface emitting laser (VCSEL) with a set of emission zones configured to emit structured light forming a set of dots; a single-element collimating lens aligned to the two-zone VCSEL; and a tiling diffractive optical element (DOE) aligned to the single-element collimating lens, wherein the tiling DOE comprises a set of tile segments aligned to the set of emission zones, and wherein a tile segment, of the set of tile segments, is configured to project, from the set of emission zones toward portions of a target, the structured light forming the set of dots.