Under-Display Fingerprint Sensor Air Gap Reduction
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Solution Overview
Problem
Conventional display devices with fingerprint sensors face challenges in integrating ultrasonic fingerprint sensors under the display panel without increasing bezel size or altering the display panel structure, due to air gaps and performance deterioration.
Innovation Solution
A display device design that includes a transparent substrate, a display panel, a fingerprint sensor positioned under the display panel, and a drive integrated circuit, with a non-transparent film and a metallic layer to reduce air gaps and improve sensor performance, allowing for accurate fingerprint detection without altering the display panel's structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a fingerprint sensor is placed under the display panel in a screen area, then the bezel size can be reduced and screen real estate increased, but air gaps and structural interference from display components (such as prism sheets in backlight units) deteriorate sensor performance
Solution Approach 1:
The patent extracts the fingerprint sensor from the traditional bezel area and relocates it to the screen area under the display panel. This extraction allows the sensor to be positioned in a location that maximizes screen real estate while the patent subsequently addresses performance issues through additional structural modifications.
Solution Approach 2:
The patent introduces a dedicated sensor area structure that acts as an intermediary between the display panel and the fingerprint sensor. This intermediary structure eliminates air gaps and provides direct mechanical coupling, thereby resolving the performance deterioration caused by the display panel's internal components while maintaining the sensor's position in the screen area.
2Reliability
If a fingerprint sensor is placed in the bezel area outside the screen, then sensor performance is maintained with minimal interference, but the bezel size increases reducing screen real estate
Solution Approach 1:
The patent transitions the fingerprint sensor placement from the horizontal dimension (bezel area) to the vertical dimension (under the display panel in the screen area). This dimensional change allows the sensor to occupy space that would otherwise be used for display, thereby reducing bezel size while maintaining screen area.
3Area of stationary object
If the display panel structure is altered to accommodate a fingerprint sensor, then the sensor can be integrated in the screen area, but the manufacturing complexity and structural integrity may be compromised
Solution Approach 1:
The patent segments the display assembly into distinct functional layers, creating a dedicated sensor area structure that is separate from but integrated with the display panel. This segmentation allows the fingerprint sensor to be positioned in the screen area without compromising the overall structural integrity or manufacturing process of the display panel.
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
Enables effective fingerprint sensing on a screen without increasing bezel size or altering the display panel structure, enhancing sensor performance by reducing air gaps and improving light or ultrasonic wave reception efficiency.
Implementation Method 1
A fingerprint sensor is a sensor that detects a human fingerprint. Fingerprint sensors can be categorized into optical fingerprint sensors, capacitive fingerprint sensors, ultrasonic sensors, etc.
Implementation Method 2
A display device according to an embodiment of the present invention includes a transparent substrate, a display panel under the transparent substrate
Implementation Method 3
The fingerprint sensor may comprise one of an ultrasonic fingerprint sensor and an optical fingerprint sensor
Data Source
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AI summary
Disclosed is a display device including a display panel configured to be situated under a transparent substrate and display an image on a display area toward the transparent substrate, a fingerprint sensor under the display panel to detect a fingerprint contacting the transparent substrate, anda drive integrated circuit (drive IC) configured to drive the display panel.