Redundant Column Circuitry for Defect Tolerance in Imagers
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Solution Overview
Problem
Conventional semiconductor imagers are susceptible to column fixed pattern noise (FPN) and defects in column or row circuitry, which can lead to reduced image quality and require rejection of integrated circuits.
Innovation Solution
The implementation of redundant column or row circuitry with a control mechanism to selectively couple and decouple circuits, allowing defective or noisy circuits to be bypassed in favor of functional ones, ensuring that only non-defective and noise-free circuits process pixel signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant column or row circuitry is added to bypass defective circuits, then reliability and noise tolerance improve, but device complexity increases
Solution Approach 1:
The patent implements redundant copies of column or row circuits that can be activated to bypass defective circuits. These redundant circuits are identical functional duplicates that provide backup paths for signal transmission, enabling the system to tolerate defects without rejection.
Solution Approach 2:
The patent introduces dynamic switching capability between redundant circuits and functional circuits through control signals. The system can dynamically reconfigure the circuit architecture by selecting between operational circuits and redundant backup circuits based on defect detection, transforming a static circuit design into an adaptive one.
2Measurement precision
If redundant circuitry is implemented to reduce column FPN, then image quality improves, but manufacturing cost increases
Solution Approach 1:
The patent creates redundant copies of circuitry that can be used to bypass defective circuits and reduce column fixed pattern noise. These copies are manufactured using the same fabrication processes, so while they increase the number of components, they do not require entirely new manufacturing techniques, thereby controlling the increase in manufacturing cost.
Solution Approach 2:
The patent modifies the operational parameters of the circuit system by introducing redundant paths and changing the signal routing configuration. This allows the system to compensate for defects and reduce FPN through parameter-level adjustments rather than requiring complete circuit redesign, thus managing manufacturing complexity and cost.
Data Source
AI summary
A column circuitry architecture for an imager includes redundant column or row circuits. The column or row circuitry includes a number of redundant column or row circuits. Each column or row circuit include circuitry for controllably coupling the column or row circuit to one of plural signal lines from an array of pixels. A control mechanism is used to select a configuration of plural column or row circuits in the column or row circuitry. In this manner, some column or row circuits are decoupled from the pixel in favor of other column or row circuits. The decoupled column or row circuits may include defective or noisy circuits.