Depth Expansion Apparatus Optical Path Interval
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Solution Overview
Problem
Existing methods for expanding the depth of focus in optical systems, such as combining images at different focal positions, often result in unnatural images or insufficient depth expansion due to limitations in resolution and optical path intervals, leading to blurring and fatigue in observation.
Innovation Solution
A depth expansion apparatus comprising an image pickup optical system and device that form and capture reference images at different focal positions, with specific conditional expressions for optical path intervals and numerical apertures to generate a depth-expanded image by processing luminance changes across pixels, ensuring natural image appearance and reduced fatigue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If images at different focal positions are combined to expand depth of focus, then depth of focus is expanded, but image naturalness deteriorates due to resolution limitations and optical path interval constraints
Solution Approach 1:
The patent applies parameter changes by optimizing the optical path interval between image pickup surfaces and adjusting numerical aperture values to satisfy specific conditional expressions. This ensures that when multiple images at different focal positions are combined, the resolution and depth of focus are properly balanced, preventing unnatural image artifacts while expanding the depth of focus effectively.
Solution Approach 2:
The patent employs dynamics by using image pickup devices that can be positioned at multiple focal positions and by dynamically selecting and combining images based on their respective focal depths. This dynamic approach allows the system to adaptively create natural-looking depth-expanded images by processing luminance changes across different focal planes.
2Measurement precision
If aperture diaphragm is restricted to increase depth of field, then depth of field increases, but illumination intensity decreases
Solution Approach 1:
The patent merges multiple images captured at different focal positions to achieve expanded depth of focus without requiring aperture restriction. By combining images from multiple image pickup devices or multiple surfaces, the system maintains adequate illumination intensity while achieving the desired depth of field expansion through computational synthesis rather than optical restriction.
3Measurement precision
If optical path interval is increased to improve depth expansion, then depth expansion improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies optimal parameter ranges for the optical path interval through conditional expressions involving numerical aperture and resolution. By defining these parameter ranges, the patent achieves effective depth expansion while maintaining manufacturability, as the required precision falls within achievable manufacturing tolerances for standard optical components.
Data Source
AI summary
A depth expansion apparatus includes an image-pickup-optical-system and an image-pickup-device (hereinafter, IPS) configured to form and pick up images A and B in different focus positions, and a depth-expanded-image forming section configured to generate, based on the images A and B, a depth-expanded-image that maintains a relation between a distance from an object point to the image-pickup-optical-system and luminance. When an image side NA of the image A is represented as NA′, a resolution determined by the IPS, as R, an optical path interval between image forming surfaces for the images A and B, as d, NA of an image at a near photographing distance among the images A and B, as NAn, and NA of an image at a far photographing distance among the images A and B, as NAf, the IPS satisfy the following conditional expressions (1) and (2):R×NA′/2≦d (1)0.05≦(NAf/NAn)2≦0.9 (2).