Lidar Pixel Timing Control via Staggered Dot Activation
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Solution Overview
Problem
Current LIDAR systems using single photon avalanche diodes (SPADs) face limitations in frame rate due to sequential activation of pixels, which restricts the accuracy and speed of distance measurement, particularly in applications requiring high frame rates and precise depth maps.
Innovation Solution
Implementing a staggered dot timing configuration where pixels are activated in overlapping ranges, allowing for simultaneous or staggered activation across multiple rows, thereby reducing the integration time and enhancing the signal-to-noise ratio and frame rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sequential activation of pixels is used, then device complexity is reduced, but frame rate and productivity deteriorate
Solution Approach 1:
The detector array is divided into multiple rows, each capable of independent or staggered activation. This segmentation allows different rows to be activated at different times, enabling parallel processing of multiple spatial directions simultaneously, thereby increasing frame rate without requiring complete system redesign
Solution Approach 2:
The patent implements periodic activation patterns where pixels are activated in staggered sequences across different rows. By using periodic activation with optimized timing, the system achieves higher frame rates while maintaining manageable control complexity through repetitive, predictable activation patterns
2Measurement precision
If sequential pixel activation is used, then integration time is reduced, but measurement precision and signal-to-noise ratio deteriorate
Solution Approach 1:
The system performs preliminary activation of pixels in staggered sequences before the actual measurement window. This preliminary action allows each pixel row to have sufficient integration time for accurate measurement while maintaining overall system throughput through overlapping activation patterns across multiple rows
Solution Approach 2:
By implementing staggered activation across multiple rows, the system ensures continuous useful action throughout the measurement period. While one row is integrating signals, other rows are either activating or measuring, eliminating idle time and maintaining high measurement precision without extending total integration time
3Productivity
If overlapping pixel activation ranges are implemented, then frame rate improves, but timing control complexity increases
Solution Approach 1:
The timing control system dynamically adjusts activation patterns for different rows based on predetermined staggered sequences. This dynamic control allows overlapping activation ranges to be managed systematically, achieving high frame rates while keeping timing control complexity manageable through algorithmic patterns rather than arbitrary timing
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 approach improves the frame rate and signal-to-noise ratio by allowing partial overlap of detector timing ranges, enabling more efficient and accurate distance measurements in LIDAR systems.
Implementation Method 1
A photon impinging on a detection region of a SPAD generates an electron and hole pair via the photoelectric effect
Implementation Method 2
If the kinetic energy of the accelerated carriers is sufficient, additional carriers will be generated from the semiconductor lattice, which are in turn accelerated by the field, and may liberate further carriers in an exponentially increasing fashion
Data Source
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AI summary
An apparatus for controlling pixel scanning within a range detector, the apparatus comprising: at least one light source configured to provide a spatially controllable point light source; a detector comprising at least one light sensor configured to receive a reflected spatially controllable point light source; a controller configured to control the at least one light source, wherein the controller is configured to: control the at least one light source to generate a first series of light source pulses, associated with a first spatial direction; control the at least one light source to generate a second series of light source pulses associated with a second spatial direction, wherein the second series of light source pulses are started during the first series of light source pulses.