Touch Detection Device Voltage Line Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge is to enhance the touch detection capabilities of liquid crystal display devices while minimizing the frame size and maintaining high precision, particularly in capacitance type touch detection systems, where increasing the speed of voltage change in driving electrodes is necessary for larger and higher definition displays without compromising detection characteristics.
Innovation Solution
The solution involves a liquid crystal display device configuration with multiple voltage lines and a driving electrode driver that alternately connects selected driving electrodes to different voltage lines, allowing for faster voltage changes and reducing the impact of parasitic capacitance, thereby improving touch detection speed and accuracy without increasing the frame size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the speed of voltage change in driving electrodes is increased to achieve larger and higher definition displays, then the display size and definition are improved, but the frame size tends to increase and touch detection characteristics deteriorate
Solution Approach 1:
The patent divides the voltage supply system into multiple separate voltage lines (first voltage line, second voltage line, third voltage line) with different voltage levels. This segmentation allows independent control of voltage changes for different electrode groups, enabling fast voltage changes for touch detection while maintaining stable voltages for display operation, thus improving touch detection precision without increasing frame size.
Solution Approach 2:
The patent dynamically switches the connection of driving electrodes between different voltage lines based on operational mode (display mode vs. touch detection mode). During touch detection, selected driving electrodes are alternately connected to different voltage lines to generate rapid voltage changes, while unselected electrodes remain connected to a stable voltage line, achieving fast voltage changes only when needed without permanently increasing frame size.
2Speed
If the speed of voltage change in driving electrodes is increased to improve touch detection speed, then touch detection speed is improved, but the frame size increases due to larger circuit regions
Solution Approach 1:
The patent applies different voltage control strategies to different spatial regions. Selected driving electrodes (those actively involved in touch detection) receive rapid voltage changes through alternating connections to first and second voltage lines, while unselected driving electrodes maintain stable voltages through connection to the third voltage line. This localized dynamic control improves touch detection speed without requiring the entire frame area to support high-speed switching circuits.
Solution Approach 2:
The patent employs periodic alternating connection of selected driving electrodes to first and second voltage lines during touch detection periods. This periodic voltage switching generates the necessary rapid voltage changes for fast touch detection, while the periodic nature allows for optimized circuit design that minimizes frame area compared to continuous high-speed switching of all electrodes.
3Speed
If multiple voltage lines are used to enable faster voltage changes, then voltage change speed is improved, but the device complexity increases
Solution Approach 1:
The patent designs the multiple voltage lines to serve multiple functions: the first and second voltage lines provide rapid voltage changes for touch detection, while the third voltage line provides stable voltage for display operation and can also serve as a reference during touch detection. This multi-functionality reduces the need for additional dedicated circuits, thereby limiting the increase in device complexity while achieving fast voltage changes.
Solution Approach 2:
The third voltage line acts as an intermediary element that simplifies the overall system. It provides a stable reference voltage that mediates between the rapidly switching first and second voltage lines, reducing electromagnetic interference and simplifying the control logic. This intermediary voltage line enables faster voltage changes without proportionally increasing device complexity by providing a stabilizing reference.
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 enables faster voltage changes in driving electrodes, enhancing touch detection speed and precision, reducing erroneous detections, and allowing for larger and higher definition displays with a minimized frame size.
Implementation Method 1
the proximity of the external object is detected by using the fact that a value of a capacitance in an intersection portion in which a driving electrode and a detection electrode intersect with each other is changed by the proximity (including a contact) of the external object
Data Source
AI summary
A touch detection device is provided and includes driving electrodes for detecting an external proximity object, extending in first direction and arranged in second direction; first voltage line extending in second direction; second voltage line extending in second direction; third voltage line extending in second direction, third voltage line being narrower in than first voltage line and second voltage line in width; and switching circuit for electrically connecting driving electrodes and first voltage line, second voltage line, or third voltage line.