Image Pickup Apparatus Pupil Region Segmentation for Defocus Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image pickup apparatuses face challenges in consistently achieving satisfactory focusing due to limitations in focus detection technologies, particularly in phase-difference focus detection and depth-from-defocus methods.
Innovation Solution
The apparatus employs an image pickup element that acquires signals from different pupil regions of a photographing optical system, including a first signal from a narrow pupil region, a second signal from a wider region encompassing the first, and a third signal from an even wider region, to detect the defocus state of the optical system, enabling improved focus detection through phase-difference and contrast-based methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If phase-difference focus detection or depth-from-defocus methods are used in existing image pickup apparatuses, then focus detection capability is provided, but focusing accuracy is insufficient and satisfactory focusing cannot always be achieved
Solution Approach 1:
The pupil region is divided into multiple pupil partial regions (first, second, third) with different widths. The image pickup element captures images through each of these segmented pupil regions separately, allowing for more precise defocus state detection by comparing images from different pupil widths rather than using a single pupil region.
Solution Approach 2:
The invention changes the parameter of pupil region width by using multiple pupil partial regions with different widths. By capturing images through pupil regions of varying widths and comparing them, the system can more accurately detect defocus states and achieve reliable focusing across different shooting conditions.
2Measurement precision
If multiple pupil partial regions are used for focus detection, then focus detection capability is enhanced, but device complexity increases
Solution Approach 1:
The image pickup element serves multiple functions: it captures both ordinary images and focus detection images through the same sensor, and can capture images through multiple pupil partial regions simultaneously. This multi-functionality reduces the need for separate dedicated focus detection hardware, thereby limiting the increase in device complexity.
Solution Approach 2:
The system uses its own image pickup element to perform both ordinary imaging and focus detection functions, rather than requiring separate dedicated focus detection sensors or mechanisms. The image pickup element itself provides the focus detection capability by capturing images through different pupil partial regions.
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 enhances focusing accuracy by effectively calculating defocus states and image shift amounts, allowing for both phase-difference and contrast-based focus detection, thereby improving the overall focusing performance of the image pickup apparatus.
Implementation Method 1
an image pickup element configured to photoelectrically convert an object image, which is generated by a photographing optical system
Data Source
AI summary
An image pickup apparatus, including: an image pickup element configured to photoelectrically convert an object image; a signal acquisition unit configured to acquire a first signal obtained from a light flux that has passed through a first pupil partial region, a second signal obtained from a light flux that has passed through a second pupil partial region, and a third signal obtained from one of a light flux that has passed through a region that includes the first pupil partial region and is wider than the first pupil partial region, and a light flux that has passed through a region that includes the second pupil partial region and is wider than the second pupil partial region; and a defocus state detection unit configured to detect a defocus state based on at least one of the first signal and the second signal, and the third signal.