Lidar 2D Receiver Array Multiplexer Channel Reduction
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Solution Overview
Problem
Current LIDAR systems with 2D photodetector arrays require a large number of output channels for readout, increasing the size and complexity of the readout circuit, which can be inefficient and prone to background light interference.
Innovation Solution
A LIDAR system with a 2D photodetector array and a multiplexer that selectively couples receiving pixels to output channels based on the receiving direction, reducing the number of necessary output channels and improving signal-to-noise ratio by distributing background light across multiple columns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a 2D photodetector array is used to receive reflected light beams, then the LIDAR system can achieve comprehensive spatial detection capability, but the number of output channels required increases significantly, leading to increased readout circuit size and complexity
Solution Approach 1:
The patent divides the 2D photodetector array into multiple 1D pixel columns, each independently coupled to a shared readout circuit. This segmentation allows the system to maintain the spatial detection capabilities of a 2D array while reducing readout complexity by processing data column-by-column through a single shared circuit path.
Solution Approach 2:
The patent implements a shared readout circuit that serves multiple pixel columns universally. This single readout circuit can sequentially read out signals from any of the multiple pixel columns, eliminating the need for dedicated readout circuits for each column and significantly reducing overall system complexity.
2Productivity
If multiple output channels are used for each pixel row, then all pixels can be read out simultaneously, but the readout circuit size and complexity increase
Solution Approach 1:
The patent employs periodic sequential reading where a single readout circuit cycles through different pixel columns in successive time periods. During each period, one column is read out completely before moving to the next column, achieving comprehensive readout without requiring multiple simultaneous channels.
Solution Approach 2:
The patent transitions from a parallel readout approach (multiple channels reading simultaneously) to a temporal dimension approach (single channel reading sequentially over time). This adds the time dimension to the readout process, allowing one channel to service multiple columns through sequential access.
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 reduces the number of output channels needed while maintaining high signal-to-noise ratio and efficiency, making the LIDAR system more robust and suitable for applications like automotive use.
Implementation Method 1
each pixel of the 2D photodetector array is configured to generate electrical signals based on received light
Data Source
AI summary
A LIDAR system includes a receiver configured to receive a reflected light beam from a receiving direction, the reflected light beam having an oblong shape that extends in a lengthwise direction. The LIDAR receiver includes a two-dimensional (2D) photodetector array including a plurality of pixel rows and a plurality of pixel columns, wherein the reflected light beam, incident on the 2D photodetector array, extends in the lengthwise direction along at least one receiving pixel column of the plurality of pixel columns according to the receiving direction; an analog readout circuit including a plurality of output channels configured to read out electrical signals; and a multiplexer configured to, for each reading cycle, selectively couple receiving pixels of the at least one receiving column to the plurality of output channels based on the receiving direction, while decoupling non-receiving pixels from the plurality of output channels based on the receiving direction.