Solid-State Laser Array Switching for Low-Power LIDAR Scanning
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Solution Overview
Problem
Existing LIDAR systems face challenges in achieving high resolution and low power consumption while minimizing stray light and noise, particularly in solid-state systems, and mechanical systems struggle with calibration and synchronization of sensor arrays.
Innovation Solution
A solid-state LIDAR system with synchronized emitter and photosensor arrays, utilizing VCSELs and SPADs, and micro-optics to minimize stray light, coupled with high-side and low-side switches to manage power efficiently, allowing individual channel control and improved brightness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If all emitters are activated at once in flash LIDAR systems, then the entire scene can be captured simultaneously, but power consumption increases significantly and stray light generates noise
Solution Approach 1:
The emitter array is divided into multiple independently controllable channels or groups of emitters. Instead of activating all emitters simultaneously, the system segments the emitter array and activates only specific segments corresponding to the desired scan pattern, thereby reducing power consumption while maintaining imaging capability
Solution Approach 2:
The system uses periodic scanning of the emitter array rather than simultaneous activation. Emitters are activated in sequential periods according to a scan pattern, allowing the scene to be captured line-by-line or sector-by-sector, which reduces total power consumption compared to flash illumination of the entire array at once
2Productivity
If all emitters are activated at once in flash LIDAR systems, then the entire scene can be captured simultaneously, but stray light increases and signal-to-noise ratio decreases
Solution Approach 1:
The emitter array is segmented into controlled groups that can be activated selectively. By activating only the segment corresponding to the current scan position and using optical elements to direct light only to the corresponding sensor region, stray light from other segments is prevented, improving signal-to-noise ratio
Solution Approach 2:
The harmful stray light is extracted and isolated from the signal path by using optical elements such as mirrors or prisms that direct light from activated emitters only to the corresponding sensor region, preventing stray light from reaching other sensors and degrading the signal-to-noise ratio
3Ease of operation
If mechanical scanning systems are used, then laser beam can be steered through the scene, but calibration and synchronization of sensor array with laser beam becomes challenging
Solution Approach 1:
The patent replaces mechanical scanning systems with solid-state electronic scanning. Instead of physically moving mirrors or scanners to direct the laser beam, the system uses electronic control to selectively activate emitters in a scan pattern and synchronously reads out corresponding sensor regions, eliminating mechanical calibration and synchronization issues while maintaining beam steering capability
Solution Approach 2:
The system merges the laser emission and detection functions into a single integrated solid-state module where the emitter array and sensor array are electronically synchronized. This integration eliminates the need for separate mechanical scanning components and their associated calibration and synchronization complexities
4Use of energy by moving object
If the number of light emitters is decreased, then power consumption is reduced, but quality and resolution of the resulting image deteriorates
Solution Approach 1:
The emitter array is segmented into multiple channels that can be activated independently. The system activates only the necessary number of emitters per scan line according to the required resolution, allowing flexible control over the effective number of active emitters to balance power consumption and image quality for different application requirements
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 system achieves high-resolution imaging with low power consumption, reduced stray light, and improved detection range and accuracy by optimizing power usage and minimizing cross-talk.
Implementation Method 1
The transmitter includes an array of emitters that all emit light at once
Implementation Method 2
each of the light emitters in the array can be independently controlled to emit light
Implementation Method 3
the reflected light can be received by one or more corresponding columns of photosensors
Implementation Method 4
coupled with high-side and low-side switches to manage power efficiently, allowing individual channel control and improved brightness
Data Source
Figure 1
Figure 2A~2D
Figure 3A
AI summary
An electronically scanning emitter array that includes a two-dimensional array of light emitters arranged in k emitter banks. Each of the k emitter banks can include a subset of the light emitters in the two-dimensional array and can be independently operable to emit light from its subset of emitters. The electronically scanning emitter array can further include first and second capacitor banks coupled to provide energy to the two-dimensional array of light emitters and emitter array driving circuitry coupled to the first and second capacitor banks and to the k emitter banks. Each of the first and second capacitor banks can include at least one capacitor. The emitter array driving circuitry can include a first high-side switch coupled between the first capacitor bank and a voltage source, a second high-side switch coupled between the second capacitor bank and the voltage source, and k/2 low-side switches coupled between the k emitter banks and ground; and the emitter driving circuitry can be configured to fire one emitter bank in the k emitter banks at a time according to a firing sequence until each of the k emitter banks are fired.