Focus Detection Apparatus Signal Resolution Segmentation
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Solution Overview
Problem
Existing focus detection systems face challenges in managing high data loads and heat generation during phase difference focus detection, leading to increased processing costs and complexity, particularly when using sensors with divided photoelectric conversion portions.
Innovation Solution
A focus detection apparatus and method that generates signal pairs with varying resolutions from different areas of an image sensing unit, allowing for phase difference focus detection while optimizing data amount and reducing processing load by adjusting pixel regions and signal resolutions based on focus detection accuracy needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If signals from the entire sensor surface are held for focus detection, then focus detection coverage is improved, but data amount doubles compared to non-divided sensors, increasing processing load and heat generation
Solution Approach 1:
The patent divides the sensor surface into multiple regions and processes signals from different regions separately. Instead of holding all signals from the entire sensor surface, the system segments the data and processes only necessary portions for focus detection, reducing the overall data amount while maintaining detection coverage.
Solution Approach 2:
The patent extracts only the necessary signal components required for focus detection from the sensor data. By identifying and extracting only the relevant data portions needed for phase difference calculation, the system reduces data amount while preserving focus detection capability.
2Speed
If high clock rate or parallel processing is implemented to handle increased data amount, then processing speed is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies partial action by processing only the necessary portion of sensor data for focus detection rather than all available data. This selective processing approach maintains adequate processing speed without requiring high clock rates or complex parallel processing systems.
3Measurement precision
If photoelectric conversion portions are divided into multiple portions for phase difference detection, then focus detection accuracy is improved, but data amount and processing load increase
Solution Approach 1:
The patent segments the photoelectric conversion portions into multiple divisions for phase difference detection, enabling accurate focus measurement.同时, it segments the processing approach to handle divided portions efficiently, maintaining productivity despite increased detection accuracy requirements.
Solution Approach 2:
The patent applies different processing qualities to different data regions. High-resolution processing is applied only where necessary for accurate focus detection, while other regions use reduced processing, optimizing the balance between detection accuracy and processing efficiency.
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
The approach reduces data processing requirements and maintains high focus detection accuracy by selectively using higher resolution data for precise focus detection and lower resolution data for broader, less accurate focus detection scenarios, thereby mitigating heat and cost issues.
Implementation Method 1
a two-dimensional image sensor having a microlens formed on each pixel... the divided photoelectric conversion portions receive light beams passing through different regions of the pupil of an imaging optical system through a microlens
Implementation Method 2
the photoelectric conversion portion of each pixel constituting an image sensor is divided into a plurality of portions... generate a first signal pair having a first resolution by using signals output from the plurality of photoelectric conversion elements
Data Source
AI summary
A focus detection apparatus comprises: an image sensing unit including photoelectric conversion elements for each microlens, with the microlenses being two-dimensionally arranged; a generation unit configured to generate a first signal pair having a first resolution from signals of a first area of the image sensing unit which corresponds to a predetermined focus detection area and generate a second signal pair having a second resolution lower than the first resolution from signals of a second area which corresponds to the predetermined focus detection area and is wider than the first area; a focus detection unit configured to perform phase difference focus detection processing based on at least one of the first and second signal pairs; and a recording image generation unit configured to generate a recording image from a signal output from the image sensing unit.