Optical Wedge Element for Glazing Sensor Signal Reflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical sensors placed behind inclined glazing in vehicles face significant signal attenuation due to reflection at the air/glazing interface, which impairs distance measurement, and existing solutions like antireflective coatings and optical wedge elements either increase manufacturing complexity, cost, or modify the field of view in undesirable ways.
Innovation Solution
An optical wedge element is placed between the glazing and the optical sensor, with a wedge angle optimized to minimize signal reflection and maintain the required field of view, using a scaling factor to adjust the intrinsic field of view of the sensor to match the requested configuration, and the wedge angle is set to keep the maximal angle of incidence below 40° to maximize transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If an optical wedge element is placed on the internal face of the glazing to reduce reflection, then signal transmission is improved, but the field of view is modified and the element adds weight and size
Solution Approach 1:
The patent optimizes the wedge angle parameter to a specific range (5°-15°) to balance two competing effects: a larger wedge angle reduces reflection more effectively but modifies the field of view more significantly and increases the element thickness. By carefully selecting the wedge angle within this optimized range, the patent achieves sufficient signal transmission improvement while minimizing unwanted field of view modification and keeping the element thin enough for easy integration.
2Loss of energy
If an antireflective coating is applied to the glazing to decrease reflection, then signal transmission is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces the complex and expensive antireflective coating process with a simple optical wedge element made from standard transparent materials like glass or plastic. This wedge element can be manufactured using conventional molding or cutting techniques and bonded to the glazing using standard adhesive methods, significantly simplifying the manufacturing process and reducing costs while achieving comparable or superior reflection reduction performance.
Solution Approach 2:
The optical wedge element acts as an intermediary component placed between the glazing and the optical sensor. Instead of modifying the glazing surface through complex coating processes, the wedge element serves as a separate mediator that performs the reflection reduction function, making the manufacturing process simpler and more flexible.
3Loss of energy
If the wedge angle is increased to reduce reflection further, then signal transmission is improved, but the field of view modification becomes more pronounced
Solution Approach 1:
The patent identifies an optimized range for the wedge angle (5°-15°) where the balance between reflection reduction and field of view preservation is achieved. Within this range, the wedge angle is large enough to provide significant reflection reduction (improving signal transmission) but small enough to keep field of view modification within acceptable limits. This parameter optimization resolves the contradiction by finding the optimal compromise point.
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 reduces signal reflection and absorption, maintaining accurate distance measurements while simplifying integration and reducing manufacturing complexity, and allows for a thinner optical wedge element, enhancing the overall performance and cost-effectiveness of the optical sensor system.
Implementation Method 1
an optical wedge element placed on the internal face of an inclined glazing... adapt the incident angle of the beam
Implementation Method 2
due to the thickness of the optical wedge element, it will absorb some part of the signal and will therefore lead in signal attenuation
Data Source
AI summary
A glazing includes an optical sensor facing an internal face of the glazing. An optical wedge element with an optimized wedge angle is placed on the internal face of the glazing, between the glazing and the optical sensor.