Event Driven Pixel Spatial Contrast Extraction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image sensors struggle to effectively extract spatial and temporal contrast information from scenes, leading to limitations in capturing dynamic and static event data with high accuracy and efficiency.
Innovation Solution
An event-driven sensor design featuring an arrangement of photodiodes with an inner portion surrounded by an outer portion, coupled to an event-driven circuit that includes comparator and threshold detection circuits, enables the extraction of spatial and temporal contrast information by comparing inner and outer pixel values to generate output signals indicative of brightness differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional image sensors are used to capture image light, then analog output image signals are generated, but the ability to extract spatial and temporal contrast information is limited
Solution Approach 1:
The pixel is divided into an inner region and an outer region, each independently measuring light intensity. This segmentation allows the sensor to simultaneously capture spatial contrast (difference between inner and outer regions) and temporal contrast (changes over time), resolving the limitation of conventional sensors that cannot effectively extract both types of contrast information
Solution Approach 2:
The invention adds a spatial dimension to event detection by comparing light intensity between the inner region and outer region. This creates a new dimension of spatial contrast measurement alongside the traditional temporal dimension, enabling the sensor to detect both static and dynamic events with high precision
2Measurement precision
If conventional image sensors operate with photosensitive elements, then image charge is generated proportional to light intensity, but insensitivity to flickering and improved contrast detection are not achieved
Solution Approach 1:
By segmenting the pixel into inner and outer regions and comparing their signals, the sensor can detect spatial contrast while being insensitive to uniform temporal fluctuations (flicker). The differential measurement approach eliminates common-mode flicker signals while preserving spatial contrast information
Solution Approach 2:
The event-driven circuit continuously monitors the difference between inner and outer region signals, providing real-time feedback to detect spatial contrast events. This feedback mechanism enables reliable detection of genuine contrast changes while filtering out flicker artifacts
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 design enhances the ability to detect static and temporal events, providing improved contrast information and insensitivity to flickering, while maintaining spatial event detection capabilities.
Implementation Method 1
The image sensor includes an array of pixels having photosensitive elements (e.g., photodiodes) that absorb a portion of the incident image light and generate image charge upon absorption of the image light
Data Source
AI summary
An event driven sensor includes an arrangement of photodiodes including an inner portion laterally surrounded by an outer portion. An outer pixel cell circuit is coupled to generate an outer pixel value in response to photocurrent generated by the outer portion. The outer pixel value is a binned signal representative of an average value of brightness of incident light on the arrangement of photodiodes. An inner pixel cell circuit is coupled to the inner portion to generate an inner pixel value in response to photocurrent generated by from the inner portion. An event driven circuit is coupled to the outer pixel cell circuit and the inner pixel cell circuit. The event driven circuit is coupled to generate an output signal responsive to an inner brightness indicated by the inner pixel value relative to an outer brightness indicated by the outer pixel value.