Light Receiving Circuit With Selective Pixels for Wide-FOV Ranging
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Solution Overview
Problem
Existing light receiving devices face challenges in achieving high accuracy and maximum ranging distance due to off-axis aberrations and reduced light incidence at the periphery of the field of view, leading to deteriorated imaging performance and reduced ranging accuracy.
Innovation Solution
A light receiving device with a control circuit that selectively enables and disables pixels based on pulse count, using a shared TDC configuration and a light receiving circuit with a latch circuit and transistor configuration to optimize photon detection and reduce unnecessary pulse overlap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a condenser lens with short focal length is used to ensure field of view and light amount, then the field of view increases, but the spot diameter increases with distance from center causing deteriorated imaging performance at periphery
Solution Approach 1:
The light detector array is divided into multiple pixels, and the patent selectively activates only those pixels that receive sufficient light (above threshold), disabling peripheral pixels with inadequate light incidence. This segmentation approach maintains high imaging performance in the central region while effectively utilizing the extended field of view, resolving the contradiction between FOV and imaging quality.
2Area of stationary object
If pixels at periphery are used to increase field of view, then the field of view increases, but ranging accuracy decreases due to reduced incident light
Solution Approach 1:
The patent applies different operational states to different regions of the light detector array. Central pixels with sufficient light incidence are activated for high-precision ranging measurements, while peripheral pixels with inadequate light are disabled. This local quality differentiation ensures that only pixels meeting the light threshold requirement contribute to ranging data, maintaining measurement precision across the extended field of view.
3Area of stationary object
If all pixels are enabled to maximize light detection, then the field of view increases, but pulse overlap increases reducing counting accuracy
Solution Approach 1:
The patent extracts and removes problematic peripheral pixels from the active detection set. By disabling pixels that receive insufficient light (below threshold), the system eliminates the source of pulse overlap and counting errors. Only pixels with adequate light incidence are retained in the active set, ensuring accurate pulse counting while maintaining an extended effective field of view through selective pixel activation.
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
Enhances ranging accuracy and maintains high performance across the field of view by ensuring adequate light incidence and reducing the number of TDCs, thereby improving imaging performance and maximum ranging distance.
Implementation Method 1
a light detector array including a plurality of pixels each configured to output a pulse in response to a reaction of a light detector with a photon
Data Source
AI summary
[Object]Provided are a light receiving device and a light receiving circuit that are capable of performing highly accurate ranging with an increased field of view (FOV).[Solving Means]A light receiving device according to the present disclosure includes a light detector array including a plurality of pixels each configured to output a pulse in response to a reaction of a light detector with a photon, a counter circuit configured to count the pulse outputted from at least one of the pixels of the light detector array, and a control circuit configured to select, from the light detector array, one of the pixels to be enabled and one of the pixels to be disabled, on the basis of the number of counts of the pulse from the counter circuit.