Imaging Apparatus Signal Segmentation for Phase Difference AF Accuracy
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Solution Overview
Problem
Conventional solid-state imaging devices with phase difference AF suffer from decreased focus detection accuracy due to the loss of signal from light receiving units at different beam angles within the same microlens, leading to inefficient image-plane phase difference detection.
Innovation Solution
The imaging apparatus employs a configuration with multiple light receiving units and microlenses, allowing for full-addition, partial-addition, and non-addition independent signal generation, enabling accurate focal point detection by combining signals from adjacent light receiving units and optimizing signal output for both AF shooting and main image capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only one light receiving unit signal is output per microlens in AF shooting frame, then device complexity is reduced, but measurement precision of phase difference AF decreases
Solution Approach 1:
The patent segments the signal processing by creating three distinct signal types (full-addition, partial-addition, and non-addition independent signals) from the light receiving units under each microlens. This segmentation allows the phase difference detecting unit to selectively use multiple signals for accurate focus detection while keeping the overall system structure manageable through organized signal categories.
Solution Approach 2:
The patent adds a dimensional aspect to signal processing by introducing multiple signal output modes (full-addition, partial-addition, non-addition) for each microlens group. This dimensional expansion enables the system to provide comprehensive signal options without increasing physical device complexity, allowing accurate phase difference detection through selective signal combination.
2Measurement precision
If multiple signals from same frame are utilized for phase difference detection, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent implements multi-functionality by designing the signal generating unit to produce three types of signals (full-addition, partial-addition, non-addition independent) that can all be utilized by the phase difference detecting unit. This universal signal generation approach enables accurate focus detection using multiple signals without requiring separate dedicated systems for each signal type, thereby managing complexity while improving precision.
Solution Approach 2:
The patent employs feedback mechanisms where the phase difference detecting unit receives multiple signal types and uses them to detect focus accuracy. The system can selectively combine signals based on detection needs, creating a feedback loop that optimizes focus detection precision while managing processing complexity through intelligent signal selection and combination.
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 configuration significantly enhances focus detection accuracy and maintains image quality during continuous shooting and moving image capture, ensuring high-speed and high-accuracy phase difference AF operations without degrading the main image.
Implementation Method 1
each configured to receive the light that has passed through the optical lens, convert the light into a photoelectric conversion signal
Data Source
AI summary
An imaging apparatus includes: an optical lens; light receiving units each reading a photoelectric conversion signal; microlenses each placed for every two or more of the adjacent light receiving units; a signal generating unit generating (i) a full-addition signal by adding all of the photoelectric conversion signals obtained in a predetermined frame by the two or more adjacent light receiving units, (ii) a partial addition signal by adding the photoelectric conversion signals obtained by at least one but not all of the two or more adjacent light receiving units, and (iii) non-addition independent signals that are the photoelectric conversion signals of one of the light receiving units; a phase difference detecting unit detecting a focal point from the partial addition signal and the non-addition independent signals; and a camera YC processing unit generating a main image from the full-addition signal.