Resistive Touch Panel Multiplex Switching Circuit for Stylus Mode
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Solution Overview
Problem
Conventional resistive touch panels struggle to accurately detect multiple touch points, often misinterpreting them as additional or incorrect points, especially when users inadvertently generate multiple contacts with their fingers or palms.
Innovation Solution
The implementation of a resistive touch panel with multiple electrode groups and a multiplex switching circuit that divides the panel into smaller detecting areas, allowing the control circuit to differentiate between stylus and general touch points by determining effective and ineffective touch points based on contact area and resistance, and operating in either stylus or general mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional resistive touch panel uses a single electrode configuration to detect touch points, then the device complexity is low, but the measurement precision of multiple touch points deteriorates
Solution Approach 1:
The patent divides the touch panel into multiple detecting areas by creating a grid of electrode intersections. Each detecting area is defined by four electrodes (two X-direction and two Y-direction), allowing independent detection of touch points in each region. This segmentation enables accurate detection of multiple simultaneous touch points without requiring a completely new electrode system, thus improving measurement precision while controlling device complexity.
2Measurement precision
If the touch panel operates in stylus mode to differentiate touch types, then the measurement precision of touch point types improves, but the device complexity increases due to mode differentiation logic
Solution Approach 1:
The patent uses parameter changes in the control circuit to differentiate between stylus mode and general mode operations. By monitoring specific parameters such as touch duration, pressure threshold, or contact area characteristics, the control circuit can identify whether a touch point is generated by a stylus or a finger. This allows the system to apply different detection rules for each mode, improving touch point type differentiation without requiring completely separate hardware systems.
3Measurement precision
If the touch panel uses a multiplex switching circuit to divide into detecting areas, then the measurement precision of multiple touch points improves, but the device complexity increases
Solution Approach 1:
The patent employs a multiplex switching circuit that serves multiple functions: it selectively connects different electrode pairs to the control circuit based on which detecting area is being accessed, and it enables the same hardware to operate in both stylus mode and general mode. This multi-functionality reduces the need for separate dedicated circuits for each detection mode, thereby improving multiple touch point detection precision while limiting the increase in device complexity.
4Speed
If the control circuit calculates position immediately upon touch detection, then the response speed improves, but the reliability of touch point identification deteriorates when multiple points are generated
Solution Approach 1:
The patent performs preliminary identification of the detecting area before calculating the precise touch point position. The control circuit first determines which detecting area contains the touch point by monitoring which electrode pair shows the touch signal, and only after this preliminary identification does it proceed to calculate the exact position within that area. This preliminary action ensures reliable touch point identification even when multiple points are generated simultaneously, while maintaining fast response speed.
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 solution enables accurate detection and differentiation of multiple touch points, preventing misinterpretation and improving user interaction by determining effective touch points in both stylus and general modes, enhancing the reliability of touch panel operations.
Implementation Method 1
The contact resistance Rz is the contact resistance when the two strip-shaped ITO layers contact each other
Data Source
AI summary
The invention discloses an electronic device with a touch panel and the method for controlling the same. The method includes the steps of: determining that the electronic device is operated in a stylus mode or a general mode; determining that the touch point is an effective touch point when the electronic device is in a stylus mode and the touch point on the touch panel is determined to be the first-type touch point; determining that the touch point is an ineffective touch point when the electronic device is in a stylus mode and the touch point on the touch panel is determined to be a second-type touch point; and determining that the touch point on the touch panel is an effective touch point when the electronic device is in a general mode.