Display Device Scanning Line Noise Suppression via Segmented Common Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Display devices with touch detection functions experience noise issues in scanning lines due to variations in the common electrode's potential during idle periods, leading to increased frame size and potential leakage currents, which existing technologies struggle to mitigate effectively.
Innovation Solution
A display device configuration with first and second vertical drive circuits arranged in the frame region to alternately apply vertical scanning pulses, and switches that supply the same potential to scanning lines during idle periods, reducing noise and frame size while maintaining effective touch detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the common electrode for display is used as one of the electrodes for touch sensing, then touch detection function is integrated with display function, but the potential of the common electrode varies during idle periods causing noise in scanning lines and leakage current
Solution Approach 1:
The patent segments the common electrode into two separate electrodes: a first common electrode for display and a second common electrode for touch detection. This segmentation isolates the touch detection function from the display function, preventing potential variations in the display common electrode from affecting the scanning lines and causing noise or leakage current during idle periods.
Solution Approach 2:
The patent introduces a second common electrode as an intermediary element specifically for touch detection. This intermediary electrode allows the touch detection function to operate independently from the display common electrode, acting as a mediator that enables integrated functionality while preventing harmful electrical interference between the two functions.
2Object-affected harmful factors
If first and second vertical drive circuits are arranged in the frame region to alternately apply scanning pulses, then scanning line noise is suppressed, but the frame size increases
Solution Approach 1:
The patent segments the drive circuits into first and second vertical drive circuits arranged in the frame region, with scanning lines extending between them. This segmentation allows noise suppression by alternating scanning pulse application while maintaining a compact frame structure through efficient spatial arrangement of the segmented components.
Solution Approach 2:
The patent utilizes the vertical dimension by arranging drive circuits and scanning lines in a layered configuration. The first and second vertical drive circuits are positioned with scanning lines extending between them in the vertical direction, enabling noise suppression through three-dimensional spatial utilization rather than simply expanding the horizontal frame size.
3Reliability
If touch detection operation is performed during idle period when display is stopped, then influence on display operation is reduced, but potential variation of common electrode causes noise in scanning lines
Solution Approach 1:
The patent segments the common electrode into display-specific and touch detection-specific electrodes. This allows touch detection operations during idle periods without affecting the display common electrode potential, thereby maintaining display stability while enabling noise-free touch detection during idle periods.
Solution Approach 2:
The patent extracts the touch detection function from the display common electrode by introducing a separate second common electrode for touch detection. This extraction allows touch detection to be performed independently during idle periods without introducing potential variations that would cause noise in the scanning lines or affect display operation stability.
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 effectively suppresses scanning line noise and prevents frame size increase, enhancing display quality and reducing leakage currents during idle periods in display devices with touch detection capabilities.
Implementation Method 1
capacitance is formed between a drive electrode and a touch detection electrode and varies in accordance with an external proximity object which approaches from the outside
Implementation Method 2
a switch SW coupled to a scanning line GCL supplies the same potential as that supplied to the scanning line GCL by the first vertical drive circuit or the second vertical drive circuit to the scanning line GCL in an idle period
Data Source
AI summary
According to an aspect, a display device includes: a display region in which a plurality of pixels are arranged in a matrix; a plurality of signal lines that extend in a second direction in the display region; a vertical drive circuit that is coupled to first ends of the scanning lines and applies a vertical scanning pulse to the first ends to select each row of the pixels in the display region; a horizontal drive circuit that performs a display operation of supplying an image signal to each of the pixels in the row selected by the vertical drive circuit through the signal lines; and a plurality of switches that are coupled to second ends of the scanning lines respectively. Each of the switches supplies the same potential as that supplied to the first ends by the vertical drive circuit to the second end corresponding thereto in an idle period.