LiDAR Receiver Beam Reflecting Unit Using DMDs
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Solution Overview
Problem
Conventional LiDAR receiver systems face limitations due to signal loss and reduced scanning speed caused by gaps in detector arrays and the complexity of high-speed electrical switching.
Innovation Solution
A LiDAR receiver incorporating a beam reflecting unit with digital micromirror devices (DMDs) that selectively switches DMDs to 'ON' or 'OFF' states to direct laser signals towards a detector while deflecting noise signals away, eliminating the need for a photodetector array and simplifying the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a detector array is used to receive returned light signals from different directions, then the field of view coverage is improved, but signal loss occurs due to gaps between sensor elements
Solution Approach 1:
The beam reflecting unit is divided into multiple independently controllable DMD elements arranged in an array. Each DMD element can be independently switched to direct light from different directions to a single detector, eliminating gaps between sensing elements while maintaining full field of view coverage.
Solution Approach 2:
DMD elements serve as intermediary reflective surfaces between the incoming light beams from different directions and the single detector. By dynamically adjusting the orientation of each DMD element, the system routes light signals without physical gaps, eliminating signal loss while preserving wide field of view coverage.
2Speed
If a detector array with high-speed electrical switches is used to switch signals among sensor elements, then the scanning speed is improved, but device complexity increases
Solution Approach 1:
The patent extracts the switching function from the detector array and relocates it to the beam reflecting unit. Instead of switching signals among multiple detectors using complex electrical switches, the system uses DMD elements to optically direct light from different directions to a single detector, eliminating high-speed electrical switching complexity while maintaining scanning speed.
Solution Approach 2:
The patent replaces the mechanical/electrical switching system with an optical steering system using DMD elements. The DMDs use microelectromechanical principles to physically orient reflective surfaces, substituting complex high-speed electrical switches with a more reliable optical redirection mechanism that achieves the same signal routing function with reduced complexity.
3Ease of operation
If conventional electrical switches are used to switch signals among different sensor elements, then the system operation is simplified, but the scanning speed is limited by the response speed of electrical switches
Solution Approach 1:
The patent replaces the electrical switching mechanism with a microelectromechanical optical steering system. The DMD elements physically orient reflective surfaces to direct light, providing faster response times than electrical switches while maintaining operational simplicity through centralized control of the beam reflecting unit.
Solution Approach 2:
The beam reflecting unit employs dynamically adjustable DMD elements that can rapidly change orientation in response to control signals. This dynamic optical steering capability enables fast scanning speeds while keeping the detector simple and the control system centralized, resolving the trade-off between operational simplicity and scanning speed.
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 solution enhances signal reception efficiency, reduces signal loss, and increases scanning speed by allowing high-speed operation of DMDs, enabling precise and rapid detection of laser signals across a wide field of view.
Implementation Method 1
The beam reflecting unit is configured to receive an input light beam returned from an object being scanned by the LiDAR, reflect a signal in the input light beam by at least one first DMD selectively switched to an 'ON' state
Data Source
AI summary
Embodiments of the disclosure provide receivers for light detection and ranging (LiDAR). In an example, a receiver includes a beam reflecting unit having a plurality of digital micromirror devices (DMDs). The beam reflecting unit is configured to receive an input light beam returned from an object being scanned by the LiDAR, reflect a signal in the input light beam by at least one first DMD selectively switched to an “ON” state at an operation angle to form an output signal towards a detector, reflect a noise signal in the input light beam away from the detector by at least one second DMD selectively switched to an “OFF” state at a non-operation angle. The receiver also includes the detector configured to receive the output signal.