Touch Panel Electrode Drive Circuit Position Bias Reduction
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Solution Overview
Problem
Existing touch panel input devices face challenges in maintaining consistent detection accuracy across different positions on the touch surface due to variations in drive signal strength, leading to potential deviations and inaccuracies in determining touch positions.
Innovation Solution
The touch panel input device employs a configuration with odd-numbered and even-numbered first electrode lines, where drive signals are input from opposite ends, and a drive controller manages these signals to reduce positional bias, using interlace and non-interlace drive controls to minimize crosstalk and ensure consistent signal strength, thereby enhancing detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If drive signals are input to all electrode lines from a single end, then the device structure is simple, but detection accuracy varies across different positions on the touch surface
Solution Approach 1:
The electrode lines are divided into odd-numbered and even-numbered groups, with separate drive circuits (first drive circuit and second drive circuit) controlling each group. This segmentation allows independent optimization of drive signals for different electrode line groups, enabling consistent detection accuracy across the touch surface while managing system complexity through modular architecture.
Solution Approach 2:
Different drive signals are applied to odd-numbered and even-numbered electrode lines based on their specific positional characteristics. The drive controller adjusts signal parameters locally for each electrode line group to compensate for position-dependent variations, ensuring uniform detection accuracy across the entire touch surface.
2Speed
If drive signals are applied to adjacent electrode lines simultaneously, then the detection speed is high, but crosstalk between adjacent lines increases
Solution Approach 1:
The drive controller implements periodic scanning of electrode lines by alternating between odd-numbered and even-numbered groups. This periodic action sequence allows the system to methodically detect touches across all lines while preventing simultaneous activation that would cause crosstalk, maintaining detection speed through efficient sequential scanning.
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 reduces variations in detection accuracy and improves the determination of touch positions by averaging signal strengths and minimizing positional deviations, resulting in more reliable touch detection across the touch surface.
Implementation Method 1
The touch detector detects a touch on the touch surface based on a change in capacitance between the first electrode lines and the second electrode lines
Data Source
AI summary
A touch panel input device includes a plurality of first electrode lines, a plurality of second electrode lines, a first drive circuit, a second drive circuit, a drive controller, a reception circuit, and a touch detector. The first drive circuit inputs a first drive signal to odd-numbered first electrode lines which are odd-numbered electrode lines among each of the plurality of first electrode lines from a first end portion side. The second drive circuit inputs a second drive signal to even-numbered first electrode lines which are even-numbered electrode lines among each of the plurality of first electrode lines from a second end side. The touch detector detects a touch on the touch surface based on a change in an output signal detected by the reception circuit.