Electronic Camera Wobbling Control for Auto Focus Synchronization
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Solution Overview
Problem
Digital cameras with C-MOS image sensors face challenges in performing high-speed auto focus control due to non-unique exposure timing across pixels, leading to reduced sensitivity in detecting focus changes, especially when using wobbling or scanning operations.
Innovation Solution
An electronic camera system that includes a wobbling or scanning control mechanism to synchronize the exposure timing of the focusing lens with the image sensor's progressive scanning, ensuring accurate auto focus control by optimizing the relationship between the wobbling/scanning operation and exposure timing, and utilizing an auxiliary light source for enhanced luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If wobbling operation is used for auto focus control, then focus detection capability is improved, but measurement precision deteriorates due to non-unique exposure timing across pixels
Solution Approach 1:
The patent applies preliminary action by determining the exposure timing of the central pixel before executing the wobbling operation, and using this information to synchronize the lens stop timing. This ensures that the lens is stationary during the exposure period, preventing focus changes that would otherwise occur due to wobbling movement, thereby maintaining measurement precision while preserving focus detection capability
Solution Approach 2:
The patent implements feedback by using the detected exposure timing information to adjust and synchronize the lens stop timing. The system continuously monitors the exposure timing of the central pixel and adjusts the lens stop operation accordingly, creating a closed-loop control system that maintains precision in focus change detection
2Difficulty of detecting and measuring
If scanning operation is used for auto focus control, then focus detection capability is improved, but measurement precision deteriorates due to lens movement during exposure
Solution Approach 1:
The patent applies preliminary action by determining the exposure timing of the central pixel before executing the scanning operation, and using this information to synchronize the lens stop timing. This ensures that the lens is stationary during the exposure period, preventing focus changes that would otherwise occur due to scanning movement, thereby maintaining measurement precision while preserving focus detection capability
Solution Approach 2:
The patent implements feedback by using the detected exposure timing information to adjust and synchronize the lens stop operation. The system continuously monitors the exposure timing of the central pixel and adjusts the lens stop operation accordingly, creating a closed-loop control system that maintains precision in estimated in focus value measurement
3Ease of operation
If lens stop timing is not synchronized with exposure timing, then auto focus operation simplicity is maintained, but productivity deteriorates due to reduced focus detection accuracy
Solution Approach 1:
The patent applies self-service by automatically determining the exposure timing of the central pixel and using this information to automatically synchronize the lens stop timing. The system performs the synchronization autonomously without requiring manual intervention or complex external control, thereby maintaining operational simplicity while achieving accurate focus detection
Solution Approach 2:
The patent implements feedback by using the detected exposure timing information to automatically adjust and synchronize the lens stop operation. This closed-loop control mechanism maintains focus detection accuracy while keeping the operation simple and automated
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
Enables accurate and high-speed auto focus control by synchronizing the exposure timing with the lens movement, improving focus detection sensitivity and maintaining sufficient image luminance, even in low-light conditions.
Implementation Method 1
an image sensor for exposing a plurality of two-dimensionally arranged photoelectric conversion elements to light by progressive scanning and generating a video signal by reading an electric signal from each of the photoelectric conversion elements
Implementation Method 2
utilizing an auxiliary light source for enhanced luminance
Data Source
AI summary
The present invention provides an electronic camera adapted to perform an accurate auto focus control operation at high speed. The electronic camera comprises a wobbling control section for generating a wobbling control signal for auto focus control of the electronic camera. The wobbling control section is adapted to generate the wobbling control signal for synchronizing exposure to light of a central pixel of the predetermined range in the image with the central timing of a near side stop operation and that of the period of a far side stop operation.