Charge Crosstalk Mitigation in Distance Image Sensors
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Solution Overview
Problem
In charge-distributing type range image sensors with range sensors aligned in a one-dimensional direction, charge crosstalk between adjacent sensors can lead to varying influences on ranging, making it difficult to perform accurate ranging.
Innovation Solution
By positioning the signal charge-accumulating regions in a specific configuration where the first signal charge-accumulating region is closer to one side of the charge-generating region in one direction and the second signal charge-accumulating region is closer in the other direction, ensuring that both adjacent range sensors accumulate charges in the same type of regions, thus minimizing the influence of charge crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If range sensors are arranged in a one-dimensional direction with adjacent sensors positioned close to each other, then the device can perform ranging measurements, but charge crosstalk occurs between adjacent range sensors causing varying influences on ranging accuracy
Solution Approach 1:
The patent applies asymmetry by configuring adjacent range sensors with opposite orientations of their signal charge-accumulating regions. Specifically, in one range sensor the first signal charge-accumulating region is positioned closer to the charge-generating region than the second, while in the adjacent sensor this arrangement is reversed. This asymmetric configuration ensures that charge crosstalk affecting both sensors originates from the same type of accumulating region, making the crosstalk influence consistent and enabling accurate ranging measurements despite the presence of crosstalk
2Productivity
If signal charge-accumulating regions are positioned close to the charge-generating region to improve charge collection efficiency, then charge transfer efficiency increases, but charge crosstalk between adjacent range sensors increases
Solution Approach 1:
The patent applies local quality by making each range sensor have non-uniform positioning of its signal charge-accumulating regions relative to the charge-generating region. The first and second signal charge-accumulating regions are positioned at different distances from the charge-generating region, with one closer and one farther. This creates localized variations in charge collection characteristics within each sensor, and when combined with opposite configurations in adjacent sensors, ensures that crosstalk affects both sensors equally despite the close positioning that enables efficient charge transfer
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 configuration ensures that the influence of charge crosstalk on ranging is consistent between adjacent range sensors, improving the accuracy and consistency of the ranging process.
Implementation Method 1
a charge-generating region generating charges in accordance with incident light
Data Source
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AI summary
In any three of three range sensors PBn, PAm, PAm+1 consecutively aligned in a one-dimensional direction A, first signal charge-accumulating regions FD1 are adjacent to each other in the one-dimensional direction A in the range sensor PAm positioned in a center of the three range sensors and the range sensor PBn positioned closer to one side of the one-dimensional direction A than the range sensor PAm, and the first signal charge-accumulating region FD1 and the second signal charge-accumulating region FD2 are adjacent to each other in the one-dimensional direction A in the range sensor PAm positioned in the center of the three range sensors and the range sensor PAm+1 positioned closer to an another side of the one-dimensional direction A than the range sensor PAm.