Tilt-Controlled Optical Element Mounting via Perpendicular Threads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical assembly techniques face challenges in achieving precise centering of optical elements within barrels, particularly due to thermal expansion mismatches and manufacturing tolerances, leading to lower precision and increased costs in high-precision applications.
Innovation Solution
The optical assembly employs a barrel with internal threads and a retaining ring with a load-bearing thread face perpendicular to the center axis, ensuring tilt-controlled mounting of optical elements by engaging a planar peripheral region of the optical element, thereby maintaining alignment without tilting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drop-in technique is used to mount a lens in a barrel with a retaining ring, then assembly time is short and lenses are removable, but centering precision is lower due to thermal expansion mismatches and manufacturing tolerances
Solution Approach 1:
The patent changes the geometric parameters of the thread profile, specifically setting the thread angle alpha to 0 degrees (perpendicular threads). This parameter change eliminates the tilting effect that occurs with conventional threaded connections, allowing the retaining ring to secure the lens without introducing angular misalignment, thereby maintaining high centering precision while using a simple drop-in assembly method
Solution Approach 2:
The patent introduces asymmetry in the thread design by making the threads perpendicular to the optical axis rather than following the conventional angled thread profile. This asymmetric configuration (relative to standard thread designs) prevents the retaining ring from tilting relative to the optical axis, ensuring that the lens remains properly centered during assembly and operation
2Manufacturing precision
If tight manufacturing tolerances are applied to achieve high centering precision in drop-in assemblies, then centering accuracy improves, but manufacturing costs increase
Solution Approach 1:
By changing the thread profile parameter (setting alpha = 0 degrees), the patent eliminates the need for tight manufacturing tolerances on the retaining ring and lens mounting surfaces. The perpendicular thread configuration inherently prevents tilting, so standard tolerances are sufficient to achieve high centering accuracy, significantly reducing manufacturing costs while maintaining precision
3Manufacturing precision
If active alignment is used to achieve high centering accuracy, then centering precision is very high, but equipment cost and assembly time increase
Solution Approach 1:
The patent makes the mounting structure self-aligning through the perpendicular thread design. The retaining ring automatically secures the lens in proper alignment without requiring external alignment equipment or complex adjustment procedures. The design itself provides the alignment function, eliminating the need for expensive active alignment systems
Solution Approach 2:
The perpendicular thread configuration is designed in advance to prevent tilting before assembly occurs. This preliminary design feature ensures that when the lens is inserted and secured, it is automatically positioned correctly without requiring subsequent alignment adjustments or specialized equipment
Data Source
Figure 1
Figure 2A~2C
Figure 3A
AI summary
Optical assemblies where one or more optical elements are mounted in the cavity of a barrel are provided. The optical element has a curved abutment surface engaging a seat provided in the cavity. The barrel has an inner wall provided with a set of internal threads. External threads are provided on a peripheral wall of the optical element or on a perimeter wall of a retaining ring securing the optical element within the cavity. The internal and external threads have a thread profile including a load-bearing thread face perpendicular to the center axis of the cavity. The thread profile may for example define a Buttress thread profile or a square thread profile.