Automotive Light Guide Laser Welding for Optical Fixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing automotive lighting and signaling devices face challenges in securely fixing light guides without altering their optical functionality, particularly due to issues with mechanical fastening methods like screws and ultrasonic welding, which are slow and costly, and can compromise light transmission.
Innovation Solution
The use of laser welding to connect transparent and absorbent polymeric elements at specific interface walls of the light guide, forming a mechanical and optical fixing that maintains total internal reflection, using male and housing structures to ensure a durable and efficient assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical fixing methods (screws, brackets) are used to secure the light guide, then the light guide is firmly fixed, but the assembly process becomes slow and cumbersome, reducing productivity
Solution Approach 1:
The patent replaces mechanical fixing methods (screws, brackets) with laser welding technology. The laser welding system uses optical energy to melt and fuse the light guide to the reflector, eliminating the need for mechanical fasteners. This substitution achieves both reliable fixation and high assembly speed suitable for mass production.
2Reliability
If ultrasonic welding is used to fix the light guide, then mechanical fixation is effective, but the process is slow and expensive, increasing manufacturing cost and reducing productivity
Solution Approach 1:
The patent replaces ultrasonic welding with laser welding technology. Laser welding uses focused optical energy to rapidly melt and fuse materials, achieving reliable mechanical bonding without the slow process and high costs associated with ultrasonic welding. This enables high-speed automated assembly.
3Reliability
If the light guide is fixed at portions with optical functionality (base plates or appendages), then the integrity of light guide walls is compromised, but fixation is achieved; however, this creates scars that alter light reflection and cause bright spots or shadow areas
Solution Approach 1:
The patent extracts the fixation function from the optical walls of the light guide by providing separate fixing elements (reflector, support structures) that are specifically designed for mechanical attachment. The laser guide is fixed to these supporting elements rather than directly to its own optical walls, separating the fixation function from the optical function and preserving light transmission integrity.
Solution Approach 2:
The patent introduces intermediate fixing elements (reflector, support structures) that serve as mediators between the light guide and the mounting structure. These intermediaries provide attachment points for securing the light guide without requiring modifications to its optical walls, thus preserving total internal reflection properties while achieving reliable fixation.
4Manufacturing precision
If special base plates or appendages are designed for fixing the light guide, then the integrity of optical walls is preserved, but the fixing process becomes delicate and time-consuming, reducing productivity
Solution Approach 1:
The patent replaces delicate mechanical assembly processes with automated laser welding. The laser welding system can quickly and precisely join the light guide to supporting elements without the need for delicate manual positioning and fastening, achieving both optical integrity and high production speed.
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 provides a fast, reliable, and cost-effective assembly that maintains light transmission integrity, avoiding deformation and bright spots, suitable for mass production.
Implementation Method 1
said method comprising the steps of: providing a lighting and/or signaling device... by means of a laser beam...
Implementation Method 2
said method comprising the steps of: providing a lighting and/or signaling device... by means of a laser beam... to form a weld joint
Implementation Method 3
which receives the light beam produced by the light source and transmits it towards the lenticular body... walls of the light guide having an optical function are not locally modified or altered... maintain total internal reflection
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A lighting and signaling device (4), in particular for the automotive sector, comprising: - a container body (8) delimiting a containment housing (12) closed by a lenticular body (20), which accommodates at least one first light source (24) and is closed by a lenticular body (20), a first light guide (28) configured to receive as input at least partially the light beam produced by said at least one first light source (24), transmit it by total internal reflection along a first prevailing propagation direction (Xl-Xl) and send it as output from the lenticular body (20), - at least one fixing and/or screen element (32), opaque to said light beam, associated with the first light guide (28) at a first interface wall (36), and fixed either directly or indirectly onto the container body (8) to mechanically block the first light guide (28) onto the container body (8), wherein the first light guide (28) is mechanically fixed to the fixing and/or screen element (32) by means of at least one first welding portion (40) which projects from the first interface wall (36).