Time-of-Flight Sensor Device with Asymmetric Shared Optics
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Solution Overview
Problem
Current time-of-flight sensing systems face challenges in miniaturization, increased complexity, and reduced efficiency due to mechanical constraints, parallax errors, and high electrical, optical, and thermal noise coupling, especially when integrating large numbers of elements or requiring complex control electronics for beam collimation.
Innovation Solution
A sensor device employing shared optics with a predetermined spacing between the emitter and detector devices, allowing principal rays to intersect both, which minimizes shadowing and enables larger optical components, improving signal-to-noise ratio and angular resolution without complex control electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the emitter and detector share the same optics, then the device size is reduced and miniaturization is achieved, but the reflected light is primarily focused back onto the emitter and not onto the detector, limiting sensor efficiency
Solution Approach 1:
The patent introduces asymmetric beam shaping optics with different focal lengths for the emitter and detector channels. The emitter channel lens has a first focal length while the detector channel lens has a second focal length, creating asymmetric light path geometry that directs reflected light to the detector rather than back to the emitter, thereby resolving the efficiency problem while maintaining miniaturization
Solution Approach 2:
The shared optical system is segmented into distinct emitter channel and detector channel with separate lenses and optical paths. This segmentation allows independent optimization of each channel's optical characteristics while maintaining physical integration, enabling the reflected light to be properly directed to the detector through the detector channel lens
2Reliability
If the emitter and detector are physically separated far enough, then mechanical constraints are satisfied, but the minimum separation distance increases the device complexity and limits integration
Solution Approach 1:
The patent merges the emitter and detector into a closely spaced integrated configuration on the same semiconductor substrate, eliminating the need for large physical separation. The shared optical system handles both emission and detection functions with minimal spacing between components, reducing device complexity while satisfying mechanical constraints through tight integration
3Measurement precision
If multiple elements are employed in the emitter or detector, then the detection range and angular resolution improve, but the complexity and size of the optics required to collect and focus the light increase
Solution Approach 1:
The shared optical system serves multiple functions: it acts as both emitter channel lens and detector channel lens, collects light from multiple emitter elements, and focuses light to multiple detector elements. This multi-functionality enables high angular resolution and extended detection range without proportionally increasing optical complexity, as the same optical components handle multiple tasks simultaneously
4Ease of manufacture
If the emitter and detector are integrated on the same semiconductor substrate, then manufacturing cost is reduced and integration is improved, but electrical, optical and thermal noise coupling between the highly sensitive detector and powerful emitter becomes significant
Solution Approach 1:
The patent extracts and isolates the emitter and detector regions into separate zones on the semiconductor substrate with distinct optical paths. The emitter region is positioned to emit light through a first region while the detector region receives light through a second region, physically separating the noise-generating emitter from the sensitive detector while maintaining substrate integration for manufacturing efficiency
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 enhances the signal-to-noise ratio, increases the amount of reflected light received, improves angular resolution, reduces manufacturing costs, and eliminates the need for small emitter surfaces and complex control systems, while maintaining efficient beam collimation.
Implementation Method 1
a detector device for receiving a portion of the electromagnetic radiation reflected by a target
Implementation Method 2
the optical system defines a plurality of principal rays, a number of the plurality of principal rays intersecting the detection region
Data Source
AI summary
A sensor device (100) comprises an emitter device (106) arranged to emit electromagnetic radiation and having an emission region associated therewith. The sensor device (100) also comprises a detector device (108) arranged to receive electromagnetic radiation and having a detection region associated therewith, and an optical system (122). The emission region is spaced at a predetermined distance from the detection region. The optical system (122) defines a plurality of principal rays, a number of the plurality of principal rays intersecting the detection region. The number of the plurality of principal rays also intersect the emission region.