Hybrid AF System Obstruction Handling
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Solution Overview
Problem
Conventional digital cameras using hybrid AF methods can fail to achieve precise focus when the AF sensor is obstructed, leading to flawed image capture.
Innovation Solution
An automatic focusing system that includes phase difference and contrast detection methods, with a judgment mechanism to prioritize focus control by the contrast detection method when the AF sensor is obstructed, ensuring continued focus adjustment even if the sensor is blocked.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If phase difference detection method is used for rapid focusing, then focusing speed is improved, but focusing reliability deteriorates when AF sensor is obstructed
Solution Approach 1:
The system dynamically switches between phase difference detection method and contrast detection method based on whether the AF sensor is obstructed. When the sensor is obstructed, it transitions from phase difference detection to contrast detection to maintain focusing reliability while preserving rapid focusing capability when conditions permit.
Solution Approach 2:
The system changes the detection parameter from phase difference detection to contrast detection based on sensor obstruction status. This parameter change allows the system to adapt to different operating conditions, maintaining both speed and reliability across various scenarios.
2Speed
If only phase difference detection is used, then focusing speed is improved, but measurement precision deteriorates when sensor obstruction occurs
Solution Approach 1:
The contrast detection method serves as an intermediary when the AF sensor is obstructed. It provides an alternative measurement approach that maintains focus precision by evaluating image contrast rather than relying on phase difference signals from the obstructed sensor.
Solution Approach 2:
The system dynamically selects between phase difference detection and contrast detection based on sensor obstruction. This dynamic adaptation ensures measurement precision is maintained by switching to contrast detection when phase difference detection becomes unreliable due to obstruction.
3Speed
If hybrid AF method is used, then focusing speed is improved, but adaptability deteriorates when sensor obstruction occurs
Solution Approach 1:
The system enhances adaptability by dynamically switching between phase difference detection and contrast detection methods. This dynamic adaptation allows the system to respond to sensor obstruction conditions, maintaining both rapid focusing and versatility across different operating scenarios.
Solution Approach 2:
The system achieves multi-functionality by incorporating both phase difference detection and contrast detection capabilities. This universal approach allows the system to adapt to various conditions including sensor obstruction, maintaining both speed and adaptability across different scenarios.
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 approach prevents flawed image capture by maintaining focus control through contrast detection when the AF sensor is obstructed, allowing for precise and reliable image shooting.
Implementation Method 1
a phase difference detection portion which detects phase difference of an image as a result of image focus performed in a sensor array for ranging
Implementation Method 2
a contrast detection portion which detects a contrast value of a shot image acquired by an image sensor which images an object
Data Source
AI summary
A user by halfway depressing (S12) a shutter button acquires (S13, S14) the output OR and the output OL of a sensor array. Subsequently, an operation judges whether or not the absolute value of the difference between the output OR and the output OL is greater than a threshold value (S15). When judged greater than a threshold value, an operation initiates a warning notification to the user (S17, S18) and AF processing by a contrast detection method is performed. Meanwhile, when judged less than a threshold value, the focus lens is moved so focus can be performed toward the distance to an object with a phase difference detection method (S20). Then, the focus lens is moved from the existing focus lens position by a narrow range and the focus lens is moved to the lens position constituting the highest contrast value (S21).