Mobile Camera Focusing via Phase Detection Pre-Scan
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Solution Overview
Problem
Current focusing methods in mobile terminals, such as phase detection autofocus and contrast detection autofocus, are inefficient and require multiple scans, leading to prolonged focusing times and reduced service life of hardware components.
Innovation Solution
A focusing method that determines a first and second step angle based on fitting schemes for focus value and defocus value sampling parameter groups, allowing for efficient focusing without multiple scans by determining a third step angle for a first scan when necessary, thereby reducing focusing time and hardware costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase detection autofocus or contrast detection autofocus is used, then focusing accuracy can be achieved, but focusing time is prolonged and hardware service life is reduced
Solution Approach 1:
The patent performs a pre-scan using phase detection autofocus to roughly determine a large focusing region before conducting an accurate scan. This preliminary action narrows down the search area, allowing the subsequent accurate focusing to be completed faster with fewer steps, thus reducing overall focusing time while maintaining accuracy
Solution Approach 2:
The patent divides the focusing process into two segments: a coarse scanning phase using phase detection to identify a large focusing region, and a fine scanning phase to precisely determine the focal position within that region. This segmentation allows each phase to optimize for its specific task, improving overall efficiency
2Measurement precision
If multiple scans are performed to determine focusing position, then focusing accuracy is improved, but hardware service life is reduced
Solution Approach 1:
The patent performs a pre-scan using phase detection autofocus to roughly determine a large focusing region before conducting an accurate scan. This preliminary action narrows down the search area, allowing the subsequent accurate focusing to be completed faster with fewer steps, thus reducing overall focusing time while maintaining accuracy
Solution Approach 2:
The patent divides the focusing process into two segments: a coarse scanning phase using phase detection to identify a large focusing region, and a fine scanning phase to precisely determine the focal position within that region. This segmentation allows each phase to optimize for its specific task, improving overall efficiency
Data Source
Figure 1A
Figure 1B~1C
Figure 2
AI summary
A focusing method and a related product are provided according to implementations of the present disclosure. The method includes the following. A set of FV sampling parameter groups and a set of phase difference defocus value sampling parameter groups are obtained. A first mapping relation between step angles and FVs is determined according to the set of FV sampling parameter groups and a first predetermined fitting scheme, and a second mapping relation between the step angles and defocus values is determined according to the set of defocus value sampling parameter groups and a second predetermined fitting scheme, where the step angles are step angles of a camera driving device of a camera module. A first step angle in a first step angle set is determined according to the first mapping relation, and a second step angle in a second step angle set is determined according to the second mapping relation. Focusing is completed according to the first step angle and the second step angle. In the implementations of the present disclosure, a speed of focusing of the mobile terminal is increased, and service life of focusing-related hardware components is prolonged.