Image Sensor Verification Circuitry for On-Chip Testing
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Solution Overview
Problem
Existing imaging systems face challenges in generating repeatable verification signals to test the components of image sensors, which can add complexity and cost to manufacturing, particularly in critical applications like vehicle safety systems where continuous monitoring of imaging system components is necessary.
Innovation Solution
Incorporating verification circuitry within image sensors that generates a non-uniform distribution of pixel verification signals across the image pixel array using a switchable or variable voltage supply, allowing for on-the-fly verification without requiring concurrent operation of the imaging system, and comparing the verification image data to a predetermined standard to ensure proper function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate and dedicated verification system is provided to test imaging system components, then verification capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The verification circuitry is merged with the image sensor by integrating it into the same semiconductor substrate. The verification circuitry shares the power supply network with the image pixel array, eliminating the need for separate verification hardware and reducing overall system complexity while maintaining verification capability.
Solution Approach 2:
The power supply network serves dual purposes: it provides power to the image pixel array during normal imaging operations and acts as a verification signal distribution network when verification mode is activated. This multi-functionality eliminates redundant components and reduces device complexity.
2Ease of manufacture
If verification circuitry is integrated into the image sensor, then manufacturing cost is reduced, but generating repeatable verification signals becomes difficult
Solution Approach 1:
The verification circuitry changes the voltage parameter supplied to specific regions of the power supply network to generate verification signals. By adjusting voltage levels across different pixel regions, the system creates repeatable, distinguishable verification patterns that can be reliably detected and compared against expected outcomes.
Solution Approach 2:
Different regions of the power supply network receive different voltage levels during verification operations. This local differentiation creates unique verification signatures for different pixel regions, enabling repeatable and identifiable verification signals while using the same integrated circuit structure.
3Ease of manufacture
If conventional verification methods are used, then system cost is reduced, but continuous monitoring during operation is not achieved
Solution Approach 1:
The verification circuitry can operate continuously during image sensor operation without requiring system shutdown or concurrent operation. The integrated design allows verification signals to be generated and processed in real-time, enabling continuous monitoring of imaging system components during actual operation.
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 solution enables continuous, reliable verification of image sensor components during operation, reducing the risk of faulty data input into active control systems and enhancing vehicle safety by providing real-time monitoring and alert mechanisms for potential issues.
Implementation Method 1
verification circuitry for applying a verification voltage to a power supply network of the image pixel array
Data Source
AI summary
Imaging systems may be provided with image sensors having verification circuitry. Verification circuitry may be configured to verify proper operation of the image sensor during operation. Verification circuitry may include one or more switchable voltage contacts configured to generate a voltage drop across a power supply network of a pixel array during verification operations. Verification circuitry may include a controllable voltage supply coupled to the power supply network of the pixel array. Verification image data may be generated by applying the voltage drop or by using the controllable voltage supply to supply a different supply voltage to each row of pixels prior to readout of that row. Verification image data may be read out using the same circuitry that is used to readout imaging data. Based on a comparison of the verification data with a predetermined standard, imaging systems may continue to operate normally or corrective action may be taken.