Imaging Apparatus Phase Difference Detection Readout Timing
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Solution Overview
Problem
Existing imaging apparatuses experience response delays in autofocus operations due to the sequential readout of pixel values from photodiode divided pixels, which can lead to delayed reflection of in-focus state changes, particularly in bright environments where frame rates are higher.
Innovation Solution
The imaging apparatus performs a second readout for phase difference detection prior to a first readout for image generation within one vertical period, and in dark environments, it employs a third readout that combines image and phase difference detection, optimizing readout operations to maintain autofocus responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sequential readout of pixel values is performed for image generation first, then phase difference detection, then autofocus responsiveness deteriorates due to response delay
Solution Approach 1:
The patent performs the second readout for phase difference detection before the first readout for image generation within the same vertical period. By executing the preliminary action of reading pixel values for autofocus calculation earlier, the system ensures that phase difference detection is completed before the next vertical period begins, thereby eliminating autofocus response delay while maintaining measurement precision.
2Speed
If multiple readout operations are performed within one vertical period, then autofocus responsiveness improves, but readout operation complexity increases
Solution Approach 1:
The patent segments the readout operations into two distinct modes: a first readout that reads addition values of pixel pairs for image generation, and a second readout that reads individual pixel values for phase difference detection. By dividing the readout process into specialized segments with different purposes and data requirements, the system achieves fast autofocus operation while managing complexity through clear functional separation.
Solution Approach 2:
The patent dynamically switches between different readout modes based on operational requirements. The control unit determines whether to perform the first readout, second readout, or both within a vertical period, allowing the system to adapt its readout complexity to the current autofocus needs and image generation requirements, thereby optimizing performance while controlling complexity.
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 autofocus responsiveness by allowing phase difference detection to be completed before the next vertical period, ensuring timely focus adjustments and maintaining performance across varying light conditions.
Implementation Method 1
an imaging element including photodiode divided pixels
Data Source
AI summary
An imaging apparatus includes an imaging element including photodiode divided pixels, and a control unit. The control unit performs control to execute first readout in which an addition value of a first pixel and a second pixel constituting a photodiode divided pixel is read out as a pixel value constituting an image and second readout of performing readout in which a value of the first pixel and a value of the second pixel used for phase difference detection can be obtained from a photodiode divided pixel that is not a readout target in the first readout. In this case, the first readout is performed after performing the second readout in one vertical period.