iToF Sensor Pixel Array Segmentation for Distance Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Indirect time-of-flight (iToF) sensors face limitations in distance measurement range due to external light interference and saturation issues, particularly for nearby objects, leading to depth errors and restricted operational range.
Innovation Solution
The proposed image sensing apparatus employs a pixel array with pixels configured to convert light into electrical signals, and a processor that generates and extracts differences in charge quantities with varying exposure times and phases, allowing for enhanced distance measurement range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the iToF sensor uses a pixel configured with two taps for performance, then measurement precision is improved, but device complexity increases and requires two frames for calculation
Solution Approach 1:
The pixel array is divided into multiple regions with different integration times. Specifically, some pixels use a first integration time while other pixels use a second integration time that is different from the first. This segmentation allows the system to capture both near and far objects effectively without requiring complex per-pixel dual-tap structures, thereby reducing device complexity while maintaining measurement precision.
2Measurement precision
If the iToF sensor emits light to detect nearby objects, then measurement range is extended, but charge saturation occurs leading to depth errors
Solution Approach 1:
Different pixels are assigned different integration times based on their specific measurement needs. Pixels measuring nearby objects use a shorter first integration time to avoid charge saturation, while pixels measuring distant objects use a longer second integration time to ensure sufficient signal capture. This local quality differentiation allows each pixel to operate optimally for its specific range, preventing saturation errors while extending overall measurement capability.
3Device complexity
If the iToF system uses a limited range of distances for operation, then device complexity is reduced, but adaptability decreases
Solution Approach 1:
The system dynamically adjusts the integration time based on the measurement requirements. By switching between a first integration time for nearby objects and a second integration time for distant objects, the system adapts to different measurement scenarios. This dynamic adjustment extends the measurable distance range without significantly increasing system complexity, as the integration time switching can be implemented through standard pixel control mechanisms.
4Measurement precision
If external light removal is implemented using four charge values, then measurement precision is improved, but loss of time increases due to additional measurement cycles
Solution Approach 1:
The patent combines multiple functions into a single measurement cycle. By capturing charge values with different integration times simultaneously in one frame, the system performs both near and far object measurements without requiring separate measurement cycles. This merging of measurement functions into a single cycle reduces the time loss associated with multiple measurement passes while maintaining the precision benefits of differential charge value analysis.
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 improves the distance measurement range by utilizing charge quantity differences with different exposure times, effectively mitigating external light interference and saturation issues, thereby enhancing the operational range of iToF sensors.
Implementation Method 1
pixels are configured to convert light reflected from an object into electrical signals
Data Source
AI summary
An image sensing apparatus and method therefor are provided. The image sensing apparatus includes a pixel array comprising pixels arranged in a grid form, wherein the pixels are configured to convert light reflected from an object into electrical signals, and a processor to generate a difference of charge quantities, of which at least one of an exposure time and a phase is different, from electrical signals detected from the pixel array for each of the pixels in each frame, and extract distance information for the object.