Under-Display Fingerprint and Force Sensor Nesting
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Solution Overview
Problem
Current mobile terminals face challenges in integrating fingerprint recognition sensors and force sensors as under-display types without increasing thickness, limiting bezel reduction and fingerprint recognition accuracy.
Innovation Solution
A mobile terminal design that incorporates a fingerprint recognition sensor and a force sensor as under-display types, with the force sensor having a polygonal ring shape and measuring pressure through capacitance or resistance changes, while the fingerprint sensor recognizes fingerprints using reflected light from an OLED pixel module, and provides haptic feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a fingerprint recognition sensor and force sensor are implemented as under-display types, then the bezel can be reduced and the display area enlarged, but the thickness of the terminal increases
Solution Approach 1:
The force sensor is positioned to surround the side surface of the fingerprint recognition sensor, creating a nested configuration where the fingerprint sensor is inserted into a sensor insertion space formed by perforating the light non-transmitting layer. This nesting allows both sensors to occupy overlapping spatial volumes, reducing the overall thickness increase while maintaining both functions underneath the display.
Solution Approach 2:
The force sensor is designed with a polygonal ring shape that surrounds the side surface of the fingerprint sensor, transitioning from a planar arrangement to a three-dimensional configuration. This dimensional change allows the force sensor to detect pressure applied to the display while the fingerprint sensor remains positioned below it, enabling both functions within a compact vertical profile.
2Ease of manufacture
If a fingerprint recognition sensor is disposed at a different position (rear surface), then the force sensor can be implemented as under-display type, but the fingerprint recognition accuracy decreases
Solution Approach 1:
Both the fingerprint recognition sensor and force sensor are integrated underneath the display at the same location, merging their functions into a single under-display assembly. The force sensor surrounds the fingerprint sensor, allowing both sensors to work simultaneously at the optimal position for fingerprint recognition while maintaining the under-display configuration for haptic feedback.
3Reliability
If separate positions are used for force sensor and fingerprint sensor, then each sensor can be optimized for its function, but the device complexity increases
Solution Approach 1:
The force sensor is positioned to surround the side surface of the fingerprint recognition sensor, creating a nested configuration where the fingerprint sensor is inserted into a sensor insertion space formed by perforating the light non-transmitting layer. This nesting allows both sensors to occupy overlapping spatial volumes, reducing the overall thickness increase while maintaining both functions underneath the display.
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 simultaneous fingerprint recognition and haptic feedback without increasing the terminal's thickness, improving user experience by providing accurate fingerprint detection and tactile feedback without protrusions.
Implementation Method 1
including an OLED pixel module emitting light
Implementation Method 2
when the light emitted from the OLED pixel module is reflected by a user finger, the reflected light
Implementation Method 3
measuring pressure through capacitance or resistance changes
Implementation Method 4
measuring pressure through capacitance or resistance changes
Data Source
Figure 1A
Figure 1b~1c
Figure 2~3
AI summary
Disclosed is a mobile terminal including a display unit configured to display an image and including an OLED pixel module emitting light and a light non-transmitting layer formed therebelow, a fingerprint recognition sensor configured to recognize a user fingerprint by receiving, when the light emitted from the OLED pixel module is reflected by a user finger, the reflected light, a sensor insertion space formed by perforating a part of the light non-transmitting layer, the fingerprint recognition sensor being inserted into the sensor insertion space, and a force sensor disposed to surround a side surface of the fingerprint recognition sensor and to provide haptic feedback when pressure is applied to the force sensor.