Prism Fixing Method Using Positioning Members and Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for fixing prisms, such as dichroic prisms, often result in tilting due to non-uniform adhesive layers, especially for larger prisms where machining seating surfaces is difficult, leading to erroneous application and instability.
Innovation Solution
The method involves forming seating surfaces with a groove portion and using first and second positioning members to ensure precise alignment and uniform adhesive application, preventing adhesive from reaching these surfaces and ensuring the prism stands upright by using a jig with openings for positioning members.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple seating surfaces and adhesive reservoirs are provided to ensure uniform adhesive distribution, then prism tilting is prevented, but manufacturing complexity increases due to difficult machining of seating surfaces for large prisms
Solution Approach 1:
A positioning member with positioning protrusions is introduced as an intermediary element between the prism and the base. The positioning protrusions fit into corresponding recesses on the prism, providing mechanical alignment and support that prevents tilting without requiring complex machining of multiple seating surfaces on the prism itself.
Solution Approach 2:
The fixing function is segmented between the positioning member (which provides alignment and support) and the adhesive (which provides bonding). This segmentation allows the positioning member to handle the alignment task through simple geometric features, while the adhesive handles the bonding task, avoiding the need for complex integrated seating surface structures.
2Manufacturing precision
If seating surfaces are machined for precise alignment, then prism positioning accuracy is improved, but manufacturing time and cost increase
Solution Approach 1:
Positioning protrusions and recesses are pre-formed on the positioning member and prism respectively, establishing the precise relative position before adhesive application. This preliminary positioning action eliminates the need for time-consuming precision machining of seating surfaces during the main assembly process.
Solution Approach 2:
The positioning member serves as an intermediary that provides precise positioning through simple geometric features (protrusions and recesses) rather than requiring complex machined seating surfaces on the prism, significantly reducing manufacturing time while maintaining positioning accuracy.
3Ease of operation
If adhesive is applied directly to the prism surface, then application is simple, but adhesive may reach seating surfaces causing erroneous positioning
Solution Approach 1:
The positioning member with positioning protrusions acts as a physical barrier and guide that prevents adhesive from reaching the seating surfaces. The protrusions create a defined boundary that keeps adhesive application simple while ensuring precise positioning by blocking adhesive flow paths.
Data Source
Figure 1
Figure 2~3
Figure 4~6A
AI summary
An optical device includes a rectangular parallelepiped prism including a reflection-transmission surface for reflecting and transmitting light fluxes, a seating surface provided so that a bottom surface of the prism is fixed by an adhesive, and a groove portion provided in a part of the periphery of the seating surface. When the prism is fixed to the seating surface by the adhesive, the groove portion is configured to be capable of receiving the adhesive protruded from between the bottom surface of the prism and the seating surface when the prism is pressed against a first positioning member for determining a position of the prism so that a first side face of the prism is along a predetermined straight line and against a second positioning member for restricting a second side face orthogonal to the first side face of the prism from moving in the direction of the straight line.