Display Device Shield Electrode Parasitic Capacitance Reduction
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Solution Overview
Problem
Display devices with touch detection functions face challenges in reducing parasitic capacitance between drive electrodes and signal lines, which increases charging time and power consumption, especially when screen size or definition is increased.
Innovation Solution
The implementation of a display device with a touch detection function that includes a substrate, pixel electrodes, signal lines, drive electrodes, touch detection electrodes, and a scan driving unit, where the scan driving unit applies touch drive signals to signal lines overlapping with drive electrodes, reducing parasitic capacitance and enhancing touch detection efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the frequency of drive signals is increased to obtain larger screen size or higher definition, then the display resolution and screen size are improved, but the parasitic capacitance between drive electrode and signal line increases, causing longer charging and discharging time
Solution Approach 1:
The patent extracts the harmful parasitic capacitance effect by introducing a shield electrode between the drive electrode and signal line. This shield electrode is connected to a fixed potential (ground or reference potential), effectively isolating the electric field interaction between the drive electrode and signal line, thereby removing the parasitic capacitance that causes delayed charging and discharging.
Solution Approach 2:
The shield electrode serves as an intermediary element positioned between the drive electrode and signal line. By introducing this intermediate component and connecting it to a fixed potential, the patent mediates the electric field interaction, preventing direct capacitive coupling between the drive electrode and signal line, thus solving the timing delay problem.
2Length of stationary object
If the distance between drive electrode and signal line is reduced to achieve thinner display device, then the device thickness is reduced, but the parasitic capacitance between drive electrode and signal line increases
Solution Approach 1:
The patent removes the harmful parasitic capacitance effect by inserting a shield electrode between the drive electrode and signal line. This shield electrode, connected to a fixed potential, extracts the unwanted electric field interaction, allowing the drive electrode and signal line to be positioned closer together without suffering from increased parasitic capacitance.
Solution Approach 2:
The shield electrode acts as an intermediary that enables reduced spacing between drive electrode and signal line. By positioning this intermediate element with fixed potential between them, the patent mediates the electric field, preventing direct parasitic capacitance formation while allowing the structure to achieve thinner overall thickness.
3Ease of manufacture
If the drive electrode and signal line three-dimensionally cross each other, then the routing flexibility is improved, but a larger parasitic capacitance is produced between them
Solution Approach 1:
The patent extracts the harmful parasitic capacitance effect that arises from three-dimensional crossing of drive electrode and signal line by introducing a shield electrode. This shield electrode, connected to fixed potential, removes the unwanted capacitive coupling, allowing the routing design to maintain its three-dimensional crossing configuration for manufacturing flexibility without suffering from excessive parasitic capacitance.
Solution Approach 2:
The shield electrode serves as an intermediary element that enables three-dimensional crossing routing between drive electrode and signal line. By positioning this intermediate component with fixed potential at the crossing point, the patent mediates the electric field interaction, allowing flexible routing design while preventing harmful parasitic capacitance formation.
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 configuration reduces parasitic capacitance, lowers power consumption, allows for higher touch detection frequencies, and enables thinner, larger, or higher-definition displays by minimizing the influence of parasitic capacitance on charging and discharging.
Implementation Method 1
a plurality of touch detection electrodes that face the plurality of drive electrodes in the orthogonal direction, extend in a direction different from the direction in which the plurality of signal lines extend, and capacitively couple with the plurality of drive electrodes
Implementation Method 2
the scan driving unit applies the touch drive signal for touch detection to a signal line that faces, in an overlapping manner in the orthogonal direction, a drive electrode to which the touch drive signal is applied
Data Source
AI summary
A display device is provided and includes a substrate; pixel electrode on the substrate; a signal line coupled to the pixel electrode; a plurality of drive electrodes including a first drive electrode overlapping the signal line; a drive signal line configured to supply a drive signal to the first drive electrode; and a drive electrode switch connecting the drive signal line and the first drive electrode, wherein during a touch detection period, the drive electrode switch is closed to apply the drive signal to the first drive electrode.