Collaborative Pixel Binning for TOF Sensor Noise Reduction
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Solution Overview
Problem
Time-of-Flight (TOF) sensors face challenges in optimizing spatial resolution without hardware changes, particularly in situations with strong ambient light that introduces noise, requiring dynamic adjustments to improve depth estimation.
Innovation Solution
The concept of collaborative pixels, where each pixel shares its optical area with surrounding pixels, allowing for real-time binning and adjustment of resolution through careful control of tap control signals, creating virtual pixel zones and reducing read noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If digital domain binning is used to reduce noise, then signal-to-noise ratio is improved, but reading time and processing complexity increase
Solution Approach 1:
The patent merges multiple pixels into collaborative pixel groups that share optical area and electronically combine their signals through controlled carrier redirection. This physical merging at the sensor level achieves noise reduction equivalent to digital binning but with parallel readout capability, avoiding the time penalty of sequential processing
Solution Approach 2:
The patent creates virtual pixel zones that are electronic copies of physical pixel regions, allowing multiple virtual images to be formed simultaneously on the same physical sensor array. This enables parallel processing of binned data without increasing reading time
2Object-affected harmful factors
If spatial resolution is reduced through binning, then noise from ambient light is reduced, but detail information is lost
Solution Approach 1:
The patent implements dynamic pixel collaboration where pixel groups can be reconfigured in real-time based on scene conditions. The controller can adjust which pixels collaborate and how their optical areas are shared, allowing adaptive resolution adjustment that preserves detail information when needed while reducing ambient light noise through collaborative binning when appropriate
Solution Approach 2:
The patent applies different collaboration configurations to different regions of the sensor array. Some pixel groups can operate in collaborative mode to reduce ambient light noise, while other regions maintain full resolution for detail-critical areas, allowing selective noise reduction without uniform loss of spatial information
3Measurement precision
If more taps are added to each pixel for better TOF measurement, then depth measurement accuracy is improved, but pixel area and complexity increase
Solution Approach 1:
The patent makes pixels multi-functional through collaborative operation. Individual pixels can serve multiple measurement functions by dynamically joining different collaboration groups for different TOF phase measurements. This allows accurate depth measurement with multiple virtual taps without physically adding multiple detection regions to each pixel
Solution Approach 2:
The patent moves the tap functionality from the spatial dimension (multiple physical detection regions within a pixel) to the temporal/collaborative dimension (sequential or parallel activation of collaborating pixels). This dimensional transformation achieves multi-tap measurement capability without increasing individual pixel area
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 enables dynamic adjustment of spatial resolution, reduces read noise, and allows for efficient binning in the charge domain without requiring multiple read-outs, enhancing the accuracy of depth estimation in TOF sensors.
Implementation Method 1
photo-generated minority carriers are directed towards a detection region under the influence of an electrical field generated between the control regions
Implementation Method 2
a first source is provided for generating at least one first majority carrier current in the semiconductor layer between pairs of control regions
Implementation Method 3
When a photon is incident on the photosentitive area of a pixel, an electron-hole pair is generated
Data Source
Figure 1
Figure 2A~2C
Figure 3
AI summary
The invention relates to a detector device assisted by majority current, comprising a semiconductor layer of a first conductivity type, a plurality of control regions of the first conductivity type, at least one detection region of a second conductivity type opposite to the first conductivity type and a first source for generating a majority carrier current associated with an electrical field, characterized in that it further comprises control circuitry arranged for controlling the first source and controlling individually at least one of said first majority carrier currents.