In-Display Fingerprint Sensor Optical Layer for Wider Screens
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Solution Overview
Problem
The integration of fingerprint sensors in display devices poses a challenge due to space limitations, as they often need to be placed in bezel areas, thereby restricting the expansion of the display area.
Innovation Solution
A fingerprint sensor design that includes a light sensing layer and an optical layer with specific organic materials for light transmission and blocking, along with a planarization member to enhance manufacturing efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fingerprint sensor is disposed in a bezel area or non-display area, then the fingerprint sensor can be integrated into the display device, but the display area cannot be widened
Solution Approach 1:
The fingerprint sensor is integrated into the display area by utilizing the vertical dimension (thickness direction) rather than occupying horizontal space. The optical layer and light sensing layer are stacked vertically within the display area, allowing the fingerprint sensing function to coexist with the display function without reducing the display width or area.
2Manufacturing precision
If multiple layers (light transmitting member, light blocking member, planarization member) are added to manage light effectively, then light management efficiency improves, but device complexity increases
Solution Approach 1:
The light blocking member and planarization member are merged into a single integrated structure. The light blocking member serves dual functions: blocking light in non-sensing areas and providing a planarized upper surface for the optical layer. This merging reduces the number of separate layers and simplifies the overall device structure while maintaining effective light management.
Solution Approach 2:
The light blocking member is designed to perform multiple functions simultaneously: it blocks light from reaching the light sensing layer in areas where fingerprint sensing should not occur, and it also serves as a planarization layer that provides a flat upper surface for the optical layer structure. This multi-functionality reduces the need for additional separate layers.
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 design allows for efficient light management and effective fingerprint sensing within the display area, minimizing the impact on the display's width and enhancing the overall reliability of the fingerprint sensor.
Implementation Method 1
a light transmitting member disposed in the plurality of light transmitting areas
Implementation Method 2
a light blocking member disposed in the light blocking area
Implementation Method 3
a planarization member disposed on the light blocking member, wherein the planarization member includes a third organic material and a positive-type photosensitive material
Data Source
AI summary
A fingerprint sensor includes: a light sensing layer including a light sensing element; and an optical layer including a plurality of light transmitting areas, a light blocking area, a light transmitting member disposed in the plurality of light transmitting areas, a light blocking member disposed in the light blocking area, and a planarization member disposed on the light blocking member, wherein the light blocking area surrounds the plurality of light transmitting areas, wherein the light transmitting member includes a first organic material, wherein the light blocking member includes a second organic material, and wherein the planarization member includes a third organic material and a positive-type photosensitive material.