Imaging Apparatus Row-Selective Signal Readout for Focus Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing imaging apparatuses with multiple photoelectric conversion units per pixel face challenges in achieving desired frame rates due to increased readout time, leading to potential detection errors in focus detection, especially when signal readout is limited for focus detection.
Innovation Solution
An imaging apparatus with a plurality of photoelectric conversion units arranged in rows and columns, utilizing a processor to acquire imaging signals from the entire pupil region and a first image signal from a part of the pupil region, calculating phase differences based on these signals to reduce focus detection errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple photoelectric conversion units are provided for each pixel, then focus detection capability is improved, but readout time increases and frame rate decreases
Solution Approach 1:
The imaging element is divided into different row regions: first row region for focus detection (reading both A and B signals) and second row region for imaging only (reading addition signal). This segmentation allows simultaneous focus detection and imaging without requiring full readout of all photoelectric conversion units, thus improving frame rate while maintaining focus detection capability.
2Productivity
If readout of focus detection signals is limited to reduce readout time, then frame rate is improved, but focus detection accuracy deteriorates
Solution Approach 1:
Different readout strategies are applied to different row regions based on their specific needs. The first row region is configured for focus detection with full signal readout, while the second row region is configured for imaging with addition signal only. This local differentiation ensures focus detection accuracy is maintained in regions where it is needed while improving overall frame rate.
3Measurement precision
If signals from all photoelectric conversion units are read out individually, then focus detection accuracy is improved, but readout time increases
Solution Approach 1:
Instead of reading out signals from all photoelectric conversion units, the system performs partial readout by selecting only specific rows (first row region) for focus detection signal readout. This partial action reduces readout time significantly while still obtaining sufficient data for accurate focus detection, as the addition signal from other rows can be used for imaging purposes.
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 accurate focus detection by reducing errors caused by vignetting and improving focus detection accuracy, even under low-illuminance conditions, while maintaining a wide focus detection region and high frame rates.
Implementation Method 1
an imaging element configured to have a plurality of photoelectric conversion units for each of a plurality of pixels arranged in a row direction and a column direction
Data Source
AI summary
An imaging apparatus comprises an imaging element configured to have a plurality of photoelectric conversion units for each of a plurality of pixels arranged in a row direction and a column direction; at least one processor and memory holding a program which makes the processor function as: an acquisition unit configured to acquire an imaging signal based on a light beam that has passed through the entire pupil region of an imaging optical system and a first image signal based on a light beam that has passed through a part of the pupil region of the imaging optical system from the pixels; and a calculation unit configured to calculate a phase difference by using the imaging signal and the first image signal, wherein the calculation unit calculates the phase difference based on the first image signal and the imaging signal in the row that is the same as the first image signal or a neighboring row of the first image signal.