Fundus Observation Device Alignment Indicator Reflection Prevention
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Solution Overview
Problem
Conventional fundus observation devices struggle to capture both surface and tomographic images of the fundus oculi while preventing alignment indicators from being reflected, which hinders accurate image correction and position adjustment.
Innovation Solution
A fundus observation device comprising an illuminating optical system, an imaging optical system, an interference optical generating part, and an alignment optical system that projects alignment indicators to adjust the device's position, with a detection timing control mechanism to prevent reflection of these indicators in the image, allowing for simultaneous 2D and 3D image capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an alignment optical system projects alignment indicators on the eye for device adjustment, then the device position can be adjusted, but the alignment indicators are reflected in the fundus images causing image quality degradation
Solution Approach 1:
The alignment optical system is configured to be movable relative to the illumination optical system. The control unit controls the alignment optical system to move to a retracted position where it does not project alignment indicators during image capture, thereby preventing reflection in fundus images while maintaining ease of adjustment when needed
Solution Approach 2:
The alignment optical system projects alignment indicators onto the eye before the fundus image capture begins. This preliminary alignment action allows the device to be properly positioned and adjusted before the actual imaging process, ensuring accurate image capture without indicator reflection
2Adaptability or versatility
If the device captures both 2D surface images and 3D tomographic images simultaneously, then comprehensive fundus observation is achieved, but the device complexity increases
Solution Approach 1:
The fundus observation device merges the 2D surface image capture function (via imaging optical system) and 3D tomographic image capture function (via optical coherence tomography unit) into a single integrated device. Both imaging modes share common components such as the objective lens and image pickup unit, allowing comprehensive fundus observation while controlling device complexity through component sharing
3Device complexity
If the detection timing of illumination light and interference light is not synchronized, then the detection system is simpler, but eye movement during examination degrades image accuracy
Solution Approach 1:
The control unit synchronizes the detection timing of the illumination light (for 2D imaging) and the interference light (for 3D OCT imaging) to occur substantially simultaneously within the same examination period. This coordinated periodic detection ensures that both image types capture the same eye position, maintaining measurement precision while managing detection system complexity
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 accurate capture of both surface and tomographic images, allowing for effective correction of image positions and prevention of alignment indicator reflection, resulting in reliable 3D image formation even with eye movement during examination.
Implementation Method 1
an interference optical generating part configured to split light emitted from the light source into a signal light directed towards the fundus oculi and a reference light directed towards a reference object and to generate interference light by superposing the signal light having reached the fundus oculi and the reference light having reached the reference object
Implementation Method 2
an alignment optical system configured to project an alignment indicator on the eye to preliminarily adjust a device for the eye
Implementation Method 3
an imaging optical system configured to detect the illumination light having reached the fundus oculi
Data Source
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AI summary
A fundus observation device is provided capable of capturing both images of the surface of the fundus oculi and tomographic images of the fundus oculi, and capable of preventing alignment indicators from being reflected in the image of the fundus oculi. Image forming part 220 operates to form surface images based on results of detecting the reflection light by the fundus oculi Ef of the illumination light obtained from a fundus camera unit 1A, and operates to form tomographic images based on results of detecting interference light LC by the OCT unit 150. The fundus camera unit comprises alignment optical systems 110A and 190A, which project an alignment indicator. Detection timing controlling part 210B controls a fundus camera unit 1A and makes it detect the illumination light substantially simultaneously with detection of the interference light. Before the interference light LC and illumination light are substantially simultaneously detected, the alignment controlling part 210 controls the alignment optical system 110A and 190A and terminates the projection of the alignment light indicator. Correction processing part 225 corrects the image position of tomographic images using the surface images obtained substantially simultaneously.