Auto-Focusing Image Capture for Fundus Examination
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Solution Overview
Problem
Conventional image capturing apparatuses for fundus examination require manual alignment of the image sensor to the pupil, which is time-consuming and inconvenient.
Innovation Solution
An auto-focusing method that allows the image capturing apparatus to focus on the cornea and simultaneously determine the distance to the fundus, using multiple light sources and a lens module with a first and second lens to detect light point images and adjust the lens position for precise focusing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual alignment of the image sensor to the pupil is performed, then the fundus image can be captured, but the examination process consumes significant time and is inconvenient
Solution Approach 1:
The system performs self-alignment by automatically detecting the pupil position and calculating the required image sensor adjustment. The control unit computes the displacement needed to align the optical axis with the pupil center, enabling the apparatus to self-correct without manual intervention.
Solution Approach 2:
The patent replaces manual mechanical alignment operations with an automated optical detection and calculation system. The image sensor detects pupil position, the control unit calculates alignment parameters, and the system automatically adjusts the image sensor position, substituting human-operated mechanical adjustment with automated optical-mechanical integration.
2Measurement precision
If the image sensor is manually aligned to the pupil first, then focusing on the fundus can be achieved, but the overall process is time-consuming
Solution Approach 1:
The system performs preliminary alignment by detecting the pupil position and calculating the image sensor displacement before the actual focusing operation. This preliminary calculation of alignment parameters prepares the system in advance, so that when focusing is initiated, the image sensor is already positioned correctly, eliminating sequential manual steps.
Solution Approach 2:
The patent merges the alignment and focusing operations into a single integrated process. By detecting pupil position and calculating the required image sensor adjustment simultaneously, the system combines what were previously separate manual steps (alignment then focusing) into one automated operation, reducing total time while maintaining precision.
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 method reduces the time spent on focusing on the fundus and enhances the efficiency of fundus examination by enabling rapid adjustment to different eye curvatures, allowing for clear image capture.
Implementation Method 1
light beams generated by two rectangular illuminating slits are refracted to an image sensor to be detected. The light beams enter a crystalline lens of an eye in parallel, and the light beams are refracted and focused on locations around the retina of the fundus.
Data Source
AI summary
An image capturing apparatus and an auto-focusing method thereof are provided. The method includes transmitting light beams from light sources to an eye including a cornea, a pupil, a crystalline lens, and a fundus. The light beams are transmitted to the fundus through the cornea. The light beams transmitted to the cornea form first light point images detected by an image sensor through a lens module having first and second lenses. According to the first light point images and focal adjustment data, the first lens and the light sources are moved simultaneously to focus on the cornea. The light beams are substantially intersected at the pupil and transmitted to the fundus to form second light point images detected by the image sensor through the lens module. According to the second light point images and the focal adjustment data, the first lens is moved to focus on the fundus.