Collimator with Low Reflective Metal Layer for Fingerprint Sensing
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Solution Overview
Problem
Current display devices with fingerprint sensors face challenges in enhancing sensing precision and reducing manufacturing costs, particularly in the integration of collimators that effectively concentrate light reflected from fingerprints without distorting optical characteristics.
Innovation Solution
A collimator design incorporating a transmission pattern and a non-transmission layer with a low reflective metal material, where the transmission pattern allows light to pass through and the non-transmission layer prevents light transmission, is used in conjunction with a manufacturing method involving etching and photoresist patterning to form specific areas for optimal light concentration and reduced distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a collimator is added to the fingerprint sensor to concentrate light, then sensing precision is improved, but device complexity increases
Solution Approach 1:
The collimator structure is merged with the existing fingerprint sensor layers by integrating the transmission pattern and non-transmission layer directly into the sensor assembly. This combines the light-concentrating function with the sensing function in a unified structure, improving precision without proportionally increasing device complexity.
Solution Approach 2:
The collimator utilizes the vertical dimension by forming the transmission pattern and non-transmission layer at different heights and positions within the sensor structure. This three-dimensional arrangement allows light concentration without adding significant lateral complexity to the device.
2Measurement precision
If a non-transmission layer is added to block light, then light concentration is improved, but manufacturing cost increases
Solution Approach 1:
The non-transmission layer uses a low reflective metal material with specific optical parameters (reflectivity of about 20% or less) to achieve effective light blocking. By optimizing the material properties and thickness parameters, the design achieves good light concentration while controlling manufacturing costs through the use of thin film deposition techniques.
Solution Approach 2:
The collimator employs composite material structures combining transparent organic material for the transmission pattern with low reflective metal material for the non-transmission layer. This composite approach leverages the complementary properties of different materials to achieve both light transmission and blocking functions while maintaining cost-effectiveness.
3Reliability
If the transmission pattern is formed with precise patterns, then optical characteristics are improved, but manufacturing precision requirements increase
Solution Approach 1:
The transmission pattern is formed as a preliminary structure before adding the non-transmission layer. This preliminary formation allows for optimized pattern design that facilitates subsequent manufacturing steps, reducing the overall precision requirements by planning the structure development sequence in advance.
Solution Approach 2:
The manufacturing process uses intermediary layers and techniques (such as photoresist patterning and etching processes) to transfer the design into the transmission pattern and non-transmission layer. These intermediary steps act as buffers that convert complex design requirements into manufacturable processes with controlled precision levels.
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
The solution enhances fingerprint sensing precision by concentrating light effectively on the sensor layer while minimizing manufacturing costs and preventing distortion of optical characteristics, thus improving the overall performance of fingerprint sensing in display devices.
Implementation Method 1
The non-transmission layer includes a low reflective metal material
Implementation Method 2
a transmission pattern transmitting light
Data Source
AI summary
A collimator includes: a transmission pattern transmitting light; and a non-transmission layer disposed on at least one side surface of the transmission pattern. The non-transmission layer includes a low reflective metal material.