Shield Electrode Proximity Detection in Touch Panels
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Solution Overview
Problem
Conventional touch panel systems face challenges in reducing detection time and power consumption during finger proximity detection while preventing detection errors, especially in the standby mode before coordinate detection.
Innovation Solution
The system incorporates a shield electrode arranged opposite to the detection electrodes, utilizing electrostatic capacitance changes of the shield electrode to detect proximity or contact, and individual detection electrode changes to determine position, allowing for efficient detection time and reduced power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If electrostatic capacitance of each detection electrode is detected by switching detection electrodes in groups, then detection time is reduced, but detection accuracy deteriorates
Solution Approach 1:
The patent segments the detection process into two distinct modes: standby mode for proximity detection and detection mode for coordinate detection. In standby mode, only a subset of detection electrodes is activated to detect proximity, while in detection mode, all detection electrodes are activated to determine coordinates. This segmentation allows the system to reduce detection time during standby mode while maintaining accuracy during coordinate detection mode.
Solution Approach 2:
The patent dynamically switches between different detection electrode configurations based on operational requirements. The control unit activates different subsets of detection electrodes depending on whether the system is in standby mode or detection mode, allowing flexible adaptation between speed and accuracy requirements of different operational phases.
2Use of energy by moving object
If detection electrodes are switched in groups for proximity detection, then power consumption is reduced, but detection reliability deteriorates
Solution Approach 1:
The patent segments detection electrode activation into two modes: standby mode activates only a subset of detection electrodes for proximity detection to reduce power consumption, while detection mode activates all detection electrodes for coordinate detection to ensure reliability. This segmentation resolves the contradiction by applying different activation strategies to different operational requirements.
Solution Approach 2:
The control unit uses feedback from the detection electrodes to determine the operational state. In standby mode, the control unit monitors capacitance changes from activated detection electrodes to detect proximity, and only transitions to full detection mode when proximity is detected, ensuring reliable detection while minimizing power consumption during normal operation.
3Measurement precision
If all detection electrodes are activated for proximity detection, then detection accuracy is improved, but detection time increases
Solution Approach 1:
The patent segments the detection electrode activation based on operational mode. In standby mode, only a subset of detection electrodes is activated for proximity detection, reducing detection time. In detection mode, all detection electrodes are activated for coordinate detection, ensuring accuracy. This segmentation allows the system to optimize between speed and accuracy based on operational requirements.
Solution Approach 2:
The patent applies partial action by activating only a subset of detection electrodes during standby mode for proximity detection, rather than activating all electrodes. This partial activation is sufficient for proximity detection but would be excessive for coordinate detection, which requires full electrode activation. The control unit determines when full activation is needed based on proximity detection results.
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 approach shortens detection time, reduces power consumption, and minimizes detection errors in the finger proximity detection process, enhancing the accuracy and efficiency of touch detection in both standby and coordinate detection modes.
Implementation Method 1
Proximity or contact of an object to the first surface is detected based on electrostatic capacitance of the second electrode
Implementation Method 2
a position of the object brought in proximity to or into contact with the first surface is detected based on electrostatic capacitance of each of the plurality of first electrodes
Data Source
AI summary
A display device includes: a display panel having a front surface and a back surface and displaying an image on the front surface; a plurality of detection electrodes overlapping the display panel when seen in a plan view; and a shield electrode overlapping the display panel when seen in a plan view. The shield electrode is arranged on a side opposite to a side of the front surface with respect to the plurality of detection electrodes. Based on electrostatic capacitance of the shield electrode, proximity or contact of an object to the front surface is detected, and based on electrostatic capacitance of each of the plurality of detection electrodes, a position of the object is detected.