Spherical Lens Optical Unit for Small-Diameter Manufacturing
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Solution Overview
Problem
Existing optical units in endoscopes face challenges in maintaining optical performance and manufacturing costs due to difficulties in processing small-diameter plano-convex lenses and biconcave lenses, leading to potential eccentricity and assembly issues.
Innovation Solution
The optical unit comprises first and second lenses formed as spherical segments with adjacent convex surfaces held by a holding member, allowing press-fitting and polishing to form a lens assembly, which simplifies manufacturing and reduces diameter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If plano-convex lenses are used in the objective optical system, then the lens structure is simple, but processing becomes more difficult as the outer diameter is reduced, leading to increased eccentricity and potential deterioration of optical performance
Solution Approach 1:
The patent replaces plano-convex lenses with spherical lenses that have fully curved surfaces. This spherical geometry eliminates the flat surface that is difficult to process at small diameters, thereby reducing convex surface eccentricity while maintaining optical functionality. The spherical shape is inherently more suitable for precision manufacturing at reduced scales.
2Volume of moving object
If the diameter of plano-convex lenses is reduced, then the lens size is smaller, but it becomes difficult to distinguish between the convex surface and flat surface, making accurate fixing to the lens holder difficult and increasing manufacturing costs
Solution Approach 1:
By using spherical lenses with completely curved surfaces, the patent eliminates the ambiguity of distinguishing between convex and flat surfaces that plagues small-diameter plano-convex lenses. The spherical geometry provides clear visual and tactile identification features, facilitating accurate positioning and fixing to the lens holder during assembly.
3Reliability
If biconcave lenses are used to form an image surface outside the lens group, then the optical system can achieve the required imaging, but manufacturing small-diameter biconcave lenses is more difficult and assembly becomes more difficult
Solution Approach 1:
The patent employs spherical lenses instead of biconcave lenses, achieving the required imaging performance through a different optical configuration. The spherical geometry is significantly easier to manufacture at small diameters compared to biconcave lenses, and the spherical shape provides better mechanical features for accurate assembly and positioning.
4Ease of manufacture
If biconcave lenses are not used, then manufacturing and assembly are simplified, but a relay optical system must be provided between the lens and imaging element, increasing parts cost
Solution Approach 1:
The patent combines the imaging function with the spherical lens configuration, eliminating the need for separate biconcave lenses and relay optical systems. By using spherical lenses in a carefully designed arrangement, the system achieves the required imaging performance while reducing the total number of optical components and simplifying the 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
This approach achieves excellent optical performance with a small diameter while reducing manufacturing costs and assembly complexity.
Implementation Method 1
The holding member holds the first lens and the second lens with a frictional force
Data Source
AI summary
An optical unit includes a first lens, a second lens, and a holding member. The first lens is formed in a spherical segment having a first flat surface and a first convex spherical surface. The second lens is formed in a spherical segment having a second flat surface and a second convex spherical surface. A holding member has a first end portion that surrounds the first lens and a second end portion that surrounds the second lens. The holding member holds the first lens and the second lens with a frictional force such that the first convex spherical surface and the second convex spherical surface are adjacent to each other between the first end portion and the second end portion. The first end portion is located on the same surface as the first flat surface or closer to the second lens than the first flat surface. The second end portion is located on the same surface as the second flat surface or closer to the first lens than the second flat surface.