Ophthalmologic Imaging Autofocus with Diopter Correction Lens

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Solution Overview

Problem

Ophthalmologic imaging apparatuses with autofocus functions struggle to perform automatic focusing when a diopter correction lens is inserted into the optical path, making it difficult to adjust the focus position accurately, especially for eyes with high myopia or hyperopia, and requiring manual adjustment which is time-consuming and less precise.

Innovation Solution

The apparatus includes a first optical system with a diopter correction lens that can be inserted and removed, and a focus controller that executes different focus control processes depending on the lens's presence, allowing for automatic focusing by synchronizing the movement of the focus lens with the OCT focus control to maintain focus precision.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a diopter correction lens is inserted into the optical path to enable focus adjustment for eyes with high myopia or hyperopia, then the focusable range is extended, but the optical relationship between the imaging optical system and the focus optical system changes, making automatic focusing impossible

Engineering Contradiction:

Improvefocusable rangeVSAvoidautomatic focusing capability

Core Design Contradiction:

Adaptability or versatilityVSExtent of automation

Solution Approach 1:

The system pre-stores multiple focus positions corresponding to different diopter values in a table. When a diopter correction lens is inserted, the system retrieves the appropriate focus position from the stored data based on the inserted lens's diopter value, eliminating the need for real-time optical relationship recalculation and enabling automatic focusing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention introduces a focus position determination unit that acts as an intermediary between the diopter correction lens insertion and the autofocus mechanism. This unit determines the appropriate focus position based on the inserted lens's diopter value and controls the focus lens accordingly, bridging the gap caused by the changed optical relationship.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If manual focusing is performed when a diopter correction lens is inserted, then focus adjustment can be achieved, but it requires long time and reduces precision for users unfamiliar with the apparatus

Engineering Contradiction:

Improvefocus adjustment capabilityVSAvoidfocus adjustment time

Core Design Contradiction:

Ease of operationVSLoss of time

Solution Approach 1:

The system performs focus adjustment automatically without requiring user intervention. The focus position determination unit autonomously determines the correct focus position based on the inserted diopter correction lens and controls the focus lens accordingly, making the system self-sufficient and eliminating the time loss associated with manual focusing.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If the focus lens is moved to extend the focusable range for eyes with high myopia or hyperopia, then more diopter ranges can be covered, but the optical relationship changes prevent the split indicator images from being acquired

Engineering Contradiction:

Improvediopter correction capabilityVSAvoidfocus position determination accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system pre-calculates and stores the relationship between diopter correction lens values and corresponding focus lens positions. When a correction lens is inserted, the system directly retrieves the pre-determined focus position from stored data, ensuring precise focus positioning without relying on split indicator images that cannot be acquired.

Inventive Principle:

Principle #10Preliminary 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

Enables automatic and precise focus adjustment even with the diopter correction lens inserted, simplifying the focusing process and improving the speed and accuracy of focus control, allowing for high-precision imaging of eyes with varying diopters.

Implementation Method 1

The first optical system includes a first focus lens and a diopter correction lens, and guides light from a subject's eye to a first light receiving element

Methodology Applied

Scientific EffectRefraction: Refraction

Data Source

PatentUS10448827B2Ophthalmologic imaging apparatus

Publication Date: 2019.10.22 TOPCON CORPORATION

AI summary

An ophthalmologic imaging apparatus that includes a first optical system, a first driver, and a first focus controller. The first optical system includes a first focus lens and a diopter correction lens, and guides light from a subject's eye to a first light receiving element. The first focus lens is movable along the optical axis of a first optical path. The diopter correction lens is insertable into and removable from the first optical path. The first driver moves the first focus lens. The first focus controller executes mutually different focus control of the first driver in a removed state in which the first diopter correction lens is removed from the first optical path and in an inserted state in which the diopter correction lens is inserted into the first optical path.