Apodization Filter Diaphragm Control for Flicker Reduction
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Solution Overview
Problem
In imaging devices with apodization filters, the determination of imaging exposure frequently changes with subject brightness, leading to unnatural flicker, especially when using multiple-stage diaphragm type program diagrams as the diaphragm value approaches an open value.
Innovation Solution
The implementation of an imaging device with a program diagram storage unit that stores first, second, and third program diagrams, where the second program diagram thins out corrected diaphragm values based on apodization filter optical characteristics, allowing for stable imaging exposure settings by selecting appropriate diaphragm values and shutter speeds, and a filter detecting unit to determine the presence of the apodization filter for proper diagram selection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a multiple-stage diaphragm type program diagram with corrected diaphragm values is used in an imaging device including an apodization filter, then the determination of imaging exposure reflects the optical characteristics of the apodization filter, but the imaging diaphragm value frequently changes in accordance with a change in the brightness of a subject as the imaging diaphragm value approaches an open value
Solution Approach 1:
The patent changes the parameter of diaphragm value intervals by providing a first program diagram with uniform intervals and a second program diagram with non-uniform intervals. The second program diagram is specifically designed for apodization filter conditions, where the interval between diaphragm values is increased as the diaphragm value approaches an open value (smaller F-number), thereby reducing frequent changes while maintaining exposure accuracy through the apodization correction values.
2Illumination intensity
If the diaphragm value is corrected based on the optical characteristics of the apodization filter, then the light-reducing effect of the apodization filter is compensated, but the interval of diaphragm values is reduced as the diaphragm value approaches an open value
Solution Approach 1:
The patent segments the program diagram into multiple distinct diagrams (first program diagram with uniform intervals and second program diagram with non-uniform intervals). Each diagram is optimized for specific conditions: the first for general use without apodization filter, and the second for cases with apodization filter. This segmentation allows the system to maintain simple, appropriate characteristics for each operating condition without requiring a single complex diagram to handle all scenarios.
3Adaptability or versatility
If a linear diaphragm type program diagram is used for exposure determination, then the exposure determination is continuous, but the imaging diaphragm value changes frequently with subject brightness changes
Solution Approach 1:
The patent applies local quality by making the diaphragm value intervals non-uniform in the second program diagram. Specifically, larger intervals are used when the diaphragm value approaches an open value (smaller F-number) to prevent frequent changes, while smaller intervals are used in other ranges to maintain sufficient adaptability. This local variation in interval quality optimizes both stability and adaptability for different operating conditions.
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 solution prevents frequent changes in imaging diaphragm values due to subject brightness changes, reducing unnatural flicker and ensuring stable imaging exposure, particularly in live view and video imaging modes.
Implementation Method 1
The imaging element photoelectrically converts an incident ray and outputs an imaging signal
Data Source
AI summary
An imaging device includes an APD filter. A first program diagram is selected in a case in which the APD filter is not disposed, and a second program diagram is selected in a case in which the APD filter is disposed. A set of an imaging diaphragm value AV and an imaging shutter speed TV is determined on the basis of an exposure value obtained from a photometric value obtained from a photometric unit. The first program diagram is a multiple-stage diaphragm type program diagram. In the first program diagram, diaphragm values AV take discrete values at an interval of a first value. In the second program diagram, a part of corrected diaphragm values, which are obtained by correcting diaphragm values of the first program diagram on the basis of optical characteristics of the APD filter, are thinned out so that each interval has at least a second value.