Position Detection Sensor Layout With Through Holes for Fingerprint Access
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Solution Overview
Problem
Position detection sensors in portable electronic devices are obstructed by electromagnetic shielding materials, reducing their effective detection region and interfering with components like ultrasonic fingerprint sensors, which cannot function properly when positioned behind the sensor.
Innovation Solution
A position detection sensor with through holes in the insulating substrate allows components like fingerprint sensors to be placed behind the detection region, with position detection electrodes arranged to bypass these holes, maintaining effective detection and minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the position detection sensor is arranged on the back side of the LCD to enable full display region as input surface, then the effective detection region is maximized, but the electromagnetic shielding materials and sensor substrate obstruct ultrasonic fingerprint sensors from detecting fingerprints
Solution Approach 1:
The insulating substrate is divided into multiple regions by forming through holes, allowing different functional components to be positioned in different zones. The position detection electrodes are segmented to bypass the through holes, while the through holes themselves provide pathways for ultrasonic waves to reach the fingerprint sensor below.
Solution Approach 2:
The through holes act as intermediaries that allow ultrasonic waves to pass through the position detection sensor layer without being blocked by the electromagnetic shielding materials or sensor substrate. These through holes serve as mediators between the upper position detection layer and the lower fingerprint sensor layer.
2Reliability
If electromagnetic shielding materials and sensor substrate are provided in the position detection sensor, then the position detection function is maintained, but these materials disrupt and shield ultrasonic fingerprint sensors from functioning properly
Solution Approach 1:
The harmful electromagnetic shielding materials and sensor substrate are extracted or removed from the specific regions where ultrasonic fingerprint detection is needed. Through holes are formed to eliminate the shielding effect in those areas, allowing ultrasonic waves to pass through while maintaining the position detection function in other regions.
Solution Approach 2:
Different regions of the insulating substrate are given different properties: some regions contain electromagnetic shielding materials for position detection, while other regions (where through holes are formed) are made transparent to ultrasonic waves to allow fingerprint sensing. This creates local quality variations to satisfy different functional requirements.
3Area of stationary object
If the entire display region is made as effective detection region, then the input surface area is maximized, but components arranged on the back side cannot function effectively due to obstruction by the position detection sensor
Solution Approach 1:
The solution moves from a two-dimensional planar arrangement to a three-dimensional layered structure with vertical through holes. This allows components to be arranged in different vertical layers (position detection layer above, fingerprint sensor below) while maintaining full horizontal coverage for input detection.
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 enables the entire display region to serve as an input surface for position detection while allowing components on the backside to function without obstruction, enhancing the effective detection region and maintaining precision in position detection.
Implementation Method 1
a position detection sensor based on, for example, an electromagnetic induction system arranged on the back side of the display apparatus
Implementation Method 2
an ultrasonic fingerprint sensor is known. When the ultrasonic fingerprint sensor is used, the fingerprint of the finger placed on the surface panel can be detected without being affected by the LCD
Data Source
AI summary
A position detection sensor allows for providing, on a back side of the position detection sensor, a component that needs to be accessed from a front side thereof. The position detection sensor includes a plurality of position detection electrodes arranged on an insulating substrate, wherein a region provided with the plurality of position detection electrodes forms an effective detection region for detecting an indicated position of a position indicator. A through hole in a predetermined shape is formed in the insulating substrate in the effective detection region. The position detection electrodes are arranged to bypass the through hole along the shape of the through hole at an area intersecting the through hole.