Imaging Device Phase Difference Focus Detection Angle Error Correction
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Solution Overview
Problem
Conventional imaging devices face challenges in accurately detecting focus when a subject is slanted with respect to the phase difference detection direction, leading to ranging errors due to the inclination of the optical and sensor systems.
Innovation Solution
An imaging device with a two-dimensionally arrayed image sensor that includes focus detection pixels to restrict light flux and imaging pixels to detect out-of-focus amounts and directions using phase difference detection, along with a pixel adding section to create addition outputs for correcting angle errors, allowing for accurate focus detection even when the subject is inclined.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pixel data is added in a direction perpendicular to the out of focus direction for phase difference focus detection, then focus detection capability is improved, but ranging accuracy deteriorates when the subject is slanted with respect to the detection direction
Solution Approach 1:
The patent segments the pixel array into multiple detection regions (first detection region and second detection region) arranged in the detection direction. By dividing the detection area and processing data from different regions separately, the system can detect angle errors and correct ranging accuracy for slanted subjects while maintaining focus detection capability.
Solution Approach 2:
The patent introduces angle error detection and correction in addition to the conventional focus detection. By adding the dimension of angle measurement and correction, the system addresses the limitation of conventional methods that fail for slanted subjects, transforming a 2D focus detection problem into a 3D solution that accounts for subject orientation.
2Adaptability or versatility
If the optical system and sensor system are inclined to detect slanted subjects, then adaptability to different subject orientations is improved, but ranging errors occur due to the inclination
Solution Approach 1:
The patent implements a feedback mechanism where angle errors are detected by comparing data from multiple detection regions, and correction values are calculated and applied to adjust the ranging results. This closed-loop feedback system continuously monitors and corrects for inclination-induced errors, maintaining high ranging accuracy for slanted subjects.
Solution Approach 2:
The system performs preliminary angle error detection and correction calculations before finalizing the ranging result. By proactively identifying and correcting angle errors in the detection process, the system prevents ranging inaccuracies from occurring in the first place for slanted subjects.
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 solution enables precise focus detection and correction of angle errors, ensuring accurate ranging and focus detection for inclined subjects, improving the imaging device's ability to handle slanted subjects effectively.
Implementation Method 1
image sensor that is provided with a plurality of pixels having photoelectric conversion sections for converting an optical image that has been formed by an imaging optical system into electrical signals
Data Source
AI summary
An imaging device of the present invention comprises a focus detection section using phase difference detection based on output of the focus detection pixels, a pixel adding section, for creating respective first addition outputs by adding outputs of a first number of focus detection pixels, and creating respective second addition outputs by dividing the first number of arrays into a plurality, and adding outputs of focus detection pixels of the divided array, and a determination section for determining whether or not to correct an angle error, wherein the focus detection section executes a focus detection operation on the basis of the first addition outputs, the determination section determines whether or not to correct angle error on the basis of the plurality of second addition outputs, and in the event that the determination section has determined to correct angle error, the focus detection section corrects angle error based on a result of a focus detection operation.