Photon-Detecting Pixel Bias Control for Low-Power Distance Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Light receiving devices in distance measuring devices, such as LIDAR, face issues with increased power consumption due to background light, like sunlight, causing unnecessary multiplication and noise in photodiodes.
Innovation Solution
A light receiving device with a configuration of pixels that includes a photoelectric conversion element and a power supply to dynamically adjust the applied voltage across photodiodes, allowing for selective operation modes to minimize power consumption by switching between measurement, preparing, and non-measurement states based on light conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photodiodes continuously operate in multiplication mode to detect reflected light, then distance measurement capability is maintained, but power consumption increases due to unnecessary multiplication of background light
Solution Approach 1:
The patent applies dynamics by making the operational state of photodiodes changeable over time. Photodiodes are dynamically switched between multiplication mode and non-multiplication mode based on whether they are currently receiving reflected measurement light or only background light. This dynamic adjustment allows the system to maintain measurement precision when needed while reducing power consumption during periods when photodiodes are not contributing to distance measurement.
Solution Approach 2:
The patent implements periodic action through time-division multiplexing where photodiodes are activated in multiplication mode only during specific time windows when reflected measurement light is expected to arrive. Between these active periods, photodiodes transition to non-multiplication mode. This periodic activation pattern ensures that distance measurement capability is maintained during measurement cycles while minimizing unnecessary power consumption during idle periods.
2Area of stationary object
If all photodiodes operate simultaneously in multiplication mode, then measurement coverage is maximized, but noise from background light multiplication increases
Solution Approach 1:
The patent applies segmentation by dividing the array of photodiodes into multiple groups that operate at different time intervals. Instead of all photodiodes operating simultaneously, they are segmented into separate measurement cycles where only subsets are active at any given time. This segmentation reduces the total number of photodiodes performing multiplication at any moment, thereby reducing the cumulative noise generated from background light multiplication while still providing comprehensive measurement coverage across the entire array over time.
Solution Approach 2:
The patent uses periodic action by implementing time-division multiplexing where different groups of photodiodes are activated in alternating periods. Each group operates in multiplication mode during its designated time window and remains in non-multiplication mode during other periods. This periodic activation pattern allows the system to maintain full spatial measurement coverage across all photodiodes while limiting the simultaneous multiplication noise to only the active subset at any given time.
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 reduces power consumption by optimizing voltage settings for photodiodes, improving signal-to-noise ratio and reducing unnecessary power usage, especially in the presence of background light.
Implementation Method 1
Each of the pixels includes a photoelectric conversion element configured to be able to detect incidence of a photon
Data Source
AI summary
According to the present embodiment, a light receiving device includes a plurality of pixels. Each of the pixels includes a photoelectric conversion element configured to be able to detect incidence of a photon and a power supply portion configured to change an applied voltage applied across both ends of the photoelectric conversion element.