Compact Lens Module for Eye Fundus Camera
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Solution Overview
Problem
Conventional eye fundus observation devices are bulky, difficult to use on special patients like infants or bedridden individuals, and lack a compact design with precision light beam functionality for adjusting the eye angle during imaging.
Innovation Solution
A compact lens module and eye fundus camera design where the illumination and imaging systems share a common set of biconvex lens groups, reducing volume and ghosting effects, and incorporating a precision light beam system for precise angle adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a separate illumination lens group is added to the imaging lens group, then the illumination capability is improved, but the device volume increases
Solution Approach 1:
The patent merges the illumination lens group and imaging lens group into a single shared lens group. The illumination light passes through the same lens group that forms the image, eliminating the need for separate illumination optics. This integration reduces the overall device volume while maintaining both illumination and imaging functions.
Solution Approach 2:
The shared lens group serves dual purposes: it focuses illumination light onto the eye fundus and simultaneously forms the image of the fundus for capture. This multi-functional design allows a single optical component to perform multiple functions, reducing the number of separate components needed in the system.
2Object-generated harmful factors
If conventional lens groups are used without biconvex surfaces, then the device structure is simpler, but ghosting effects and reflected light increase
Solution Approach 1:
The patent modifies the optical parameters of the lens group by specifying that at least one lens must have biconvex surfaces. This parameter change in the lens geometry alters the light reflection characteristics, reducing ghosting effects and harmful reflections while maintaining a relatively simple overall structure.
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 solution enables a compact, portable eye fundus camera that can be used on various patients without requiring close proximity, providing accurate imaging and reducing ghosting effects while allowing precise light beam guidance for angle adjustment.
Implementation Method 1
the set of shared lens groups has biconvex surfaces for decreasing the incidence to the imaging system of the light reflected by the shared lens groups and reducing the ghosting effect
Data Source
Figure 1
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AI summary
A lens module comprises a first lens group, a second lens group and a third lens group, which are arranged from an eye fundus side to an image side in sequence. The first lens group has a positive effective focal length (EFL) and includes a first lens having two convex surfaces respectively facing the eye fundus side and the image side. The second lens group has a positive or negative EFL and includes a plurality of second lenses, wherein the second lens closest to the eye fundus side has a concave surface facing the eye fundus side. The third lens group has a positive EFL and includes a plurality of third lenses, wherein at least one third lens is a cemented lens. The abovementioned lens module decreases the volume of a lens module and reduces the ghosting effect. An eye fundus camera using the abovementioned lens module is also disclosed.