Curved Image Optical System for Capsule Endoscope

Solution Overview

Problem

Conventional image forming optical systems that produce flat images require additional lenses for aberration correction, leading to increased size and complexity, whereas systems forming curved images can reduce lens count and size while maintaining optical performance.

Innovation Solution

An image pickup apparatus with a specific optical system configuration that includes two lens components with surfaces in contact with air, forming a curved image on an image pickup surface, where the object-side lens has a concave surface and the image-side lens has a curved surface, satisfying conditional expressions to optimize curvature and aberration correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If additional lenses are added for aberration correction in flat image systems, then aberration correction is improved, but device complexity and size increase

Engineering Contradiction:

Improveaberration correctionVSAvoidlens count

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional approach by forming a curved image that naturally matches the curvature of the image pickup surface, rather than attempting to form a flat image and then correct for field curvature. This inversion eliminates the need for additional correction lenses and achieves aberration correction with fewer optical elements.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the image formation parameter from flat to curved, and optimizes the curvature radius to match the image pickup surface. This parameter change allows the system to achieve both compact size and effective aberration correction without requiring additional lenses.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If conventional wide-angle lenses are used, then angle of view is improved, but image quality and aberration correction deteriorate

Engineering Contradiction:

Improveangle of viewVSAvoidimage quality

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent employs curved surfaces for the lens components and forms a curved image that matches the curved image pickup surface. This use of curvature in the optical design enables wide-angle imaging while maintaining high image quality and effective aberration correction across the entire field of view.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Volume of moving object

If lens count is reduced for compactness, then device size is improved, but aberration correction capability deteriorates

Engineering Contradiction:

Improveoptical system sizeVSAvoidaberration correction

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent inverts the conventional approach by forming a curved image that naturally matches the curvature of the image pickup surface, rather than attempting to form a flat image and then correct for field curvature. This inversion eliminates the need for additional correction lenses and achieves aberration correction with fewer optical elements.

Inventive Principle:

Principle #13The other way round (Inversion)

4Adaptability or versatility

If flat image formation is used, then compatibility with flat sensors is improved, but optical system size and complexity increase

Engineering Contradiction:

Improvesensor compatibilityVSAvoidoptical system structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the image formation parameter from flat to curved, and optimizes the curvature radius to match the image pickup surface. This parameter change allows the system to achieve both compact size and effective aberration correction without requiring additional lenses.

Inventive Principle:

Principle #35Parameter changes

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 configuration allows for a compact, high-performance optical system with reduced lens count, improved aberration correction, and a wider angle of view, while eliminating the need for additional correction lenses.

Implementation Method 1

a lens component is a lens having an object-side surface and an image-side surface that are in contact with air in an effective optical path

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS10578853B2Image forming optical system, image pickup apparatus, optical apparatus, and capsule endoscope

Publication Date: 2020.03.03 OLYMPUS CORPORATION(JP)

AI summary

An image pickup apparatus includes an image forming optical system having lens components and an image pickup unit, and the lens component is a lens having an object-side surface and an image-side surface that are in contact with air in an effective optical path, and the image forming optical system includes in order from an object side to an image side, an object-side lens component and an image-side lens component, and the image pickup unit has an image pickup surface curved to be concave toward the object side, and a surface nearest to the object of the object-side lens component has a concave shape portion which is concave shape toward the object side in a meridional direction, in at least an off-axis effective surface, and a surface nearest to the image of the image-side lens component is a curved surface.