Microscope Optics for Matching Camera and Eyepiece Focus

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Solution Overview

Problem

AR microscopes face issues with out-of-focus images captured by the camera due to the difference in depth of focus between visual observation and camera imaging, leading to inefficiencies in user interaction.

Innovation Solution

A microscope system with a camera-side observation optical system that limits the numerical aperture using a diaphragm, ensuring the depth of focus matches that of the eyepiece-side observation, adhering to specific conditional expressions to prevent blurring and maintain image resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the camera captures images with a wide numerical aperture to maintain high resolution, then the image resolution is improved, but the depth of focus becomes shallow causing out-of-focus images

Engineering Contradiction:
Improveimage resolutionVSAvoidfocus accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the numerical aperture parameter of the camera-side optical system by introducing a diaphragm to limit it. This parameter change transforms the optical characteristics to achieve a depth of focus that matches visual observation, resolving the contradiction between high resolution (wide NA) and focus accuracy (shallow depth of focus).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies different numerical aperture characteristics to different optical paths: the eyepiece-side observation optical system maintains a wide numerical aperture for high-resolution visual observation, while the camera-side observation optical system uses a limited numerical aperture through the diaphragm to ensure adequate depth of focus for accurate focus detection.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If the user frequently checks the monitor to verify focus, then the focus accuracy is improved, but the user efficiency deteriorates due to increased time loss

Engineering Contradiction:
Improvefocus accuracyVSAvoiduser efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent makes the focus detection function self-serve by ensuring the camera captures clear images automatically when the user achieves visual focus. The system inherently provides reliable focus information through the image sensor without requiring user intervention to check the monitor, thus maintaining focus accuracy while preserving user efficiency.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent establishes a feedback mechanism where the image sensor continuously monitors the captured image quality, and this information is used to determine focus accuracy. The system provides automatic feedback about focus status through image analysis, eliminating the need for users to manually check the monitor and thereby maintaining both focus accuracy and user efficiency.

Inventive Principle:
Principle #23Feedback

3Use of energy by moving object

If the camera-side optical system uses a wide numerical aperture to match the eyepiece-side system, then the light gathering capability is improved, but the depth of focus becomes insufficient causing blurring

Engineering Contradiction:
Improvelight gathering capabilityVSAvoiddepth of focus
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent modifies the numerical aperture parameter in the camera-side optical path by introducing a diaphragm. This parameter change reduces the numerical aperture to achieve adequate depth of focus while maintaining sufficient light gathering capability for accurate focus detection, resolving the contradiction between light gathering and depth of focus.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by using a diaphragm to limit only the necessary portion of the light cone that would otherwise create excessive numerical aperture. This allows the system to maintain sufficient light gathering capability for focus detection while preventing the excessive NA that would cause shallow depth of focus and blurring.

Inventive Principle:
Principle #16Partial or excessive action

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 system effectively avoids out-of-focus images by synchronizing the depth of focus between the eyepiece and camera, allowing simultaneous clear observation and analysis without the need for frequent monitor checks, enhancing user efficiency.

Implementation Method 1

a diaphragm that is configured to limit at least a numerical aperture on an emission side of the camera-side observation optical system

Methodology Applied
Scientific EffectNumerical aperture limitation:

Implementation Method 2

an objective lens and an eyepiece and is configured to form an image of a sample observed through the eyepiece on an object side of the eyepiece with light entering from the sample through the objective lens

Methodology Applied
Scientific EffectLight refraction: Refraction

Implementation Method 3

an image sensor, an eyepiece-side observation optical system that includes an objective lens and an eyepiece

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP4296749B1Microscope system
Publication Date: 2025.12.17 EVIDENT CORP
  • EP4296749B1 patent drawingFigure 1~2
  • EP4296749B1 patent drawingFigure 3
  • EP4296749B1 patent drawingFigure 4

AI summary

A microscope system includes an eyepiece-side observation optical system that forms an image of a sample on an object side of an eyepiece, a camera-side observation optical system that forms an image of the sample on an image sensor, a diaphragm that limits a numerical aperture on the emission side of the camera-side observation optical system, and an analysis unit that analyzes the image of the sample captured by the image sensor. In a case where a numerical aperture on an object side of an objective lens is denoted by NA, the numerical aperture on the emission side of the camera-side observation optical system determined by a light flux emitted from the camera-side observation optical system toward the image sensor at capturing the image is denoted by NA', and a total magnification of the camera-side observation optical system is denoted by M1, the following is satisfied. M1×NA′<NA