Shield Layer Reconfiguration for Proximity Touch Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing proximity touch sensing technologies, such as photodiode-based sensors, are limited in functionality and cannot effectively differentiate between contact and non-contact touches, restricting the range of functions a portable terminal can perform.
Innovation Solution
An electrostatic capacity touch panel with x-electrode and y-electrode lines is used, where the shield layer is configured as a noise shielding ground or a transmit channel, forming capacitances to sense non-contact and contact touches by varying the voltage applied to these channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a photodiode-based proximity sensor is used to detect whether a user is proximate, then the device can perform basic proximity detection functions, but the functional versatility is limited and cannot differentiate between contact and non-contact touches
Solution Approach 1:
The shield layer is configured to perform multiple functions: it serves as a noise shielding ground during contact touch sensing and as a transmit channel for non-contact touch sensing. This multi-functionality enables the same hardware structure to detect both contact and non-contact touches, significantly enhancing adaptability without increasing device complexity
Solution Approach 2:
The system dynamically reconfigures the shield layer between two operational states: noise shielding ground mode for contact touch detection and transmit channel mode for non-contact touch detection. This dynamic switching allows the device to adapt its sensing capability based on the touch type, resolving the contradiction between versatility and complexity
2Adaptability or versatility
If the shield layer is used for noise shielding only, then display noise is reduced, but non-contact touch sensing capability is lost
Solution Approach 1:
The shield layer dynamically switches between noise shielding mode and non-contact sensing mode based on operational requirements. During contact touch sensing, it functions as a noise shielding ground; during non-contact touch sensing, it is reconfigured as a transmit channel. This dynamic behavior allows the system to prioritize noise reduction or sensing capability as needed
Solution Approach 2:
The electrical configuration parameters of the shield layer are changed between two states: connected to ground for noise shielding, and connected to voltage source for non-contact sensing. By changing the electrical parameter (voltage connection state), the shield layer transitions between its dual functions, resolving the contradiction between noise shielding and sensing capability
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 the detection of both non-contact and contact touches, enhancing the functionality of portable terminals by allowing for more advanced user interactions and gestures, while also providing noise shielding for the display.
Implementation Method 1
The sensing electrode structure is disposed on the first substrate for producing a first capacitance between the sensing electrode structure ad an exterior object
Implementation Method 2
The shielding layer is disposed on the second substrate, electrically connected to a ground side, and used for producing a second capacitance between the shielding layer and the sensing electrode structure when the exterior object is pressed and causes the gap to vary
Implementation Method 3
forming an electric field between the electrostatic capacity touch panel and the shield layer
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An apparatus performs proximity touch sensing, and includes a shield layer, an electrostatic capacity touch panel disposed with a specific distance above the shield layer, and a proximity touch controller for sensing a non-contact touch by supplying a voltage to the electrostatic capacity touch panel and the shield layer and thus by forming a first capacitance.