Touch Panel Sensitivity Correction via Signal Difference Analysis
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Solution Overview
Problem
The detection sensitivity of touch panel-integrated display devices deteriorates due to aged deterioration of detection electrodes, affecting the accuracy of touch position detection.
Innovation Solution
A display device with a touch panel that includes sensitivity correcting units to adjust parameters such as driving signal voltage, detection time, and signal integration based on signal differences between detection signals acquired with different driving signal amplitudes, thereby maintaining detection sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If detection electrodes are used in a touch panel-integrated display device, then touch position detection is enabled, but detection sensitivity deteriorates due to aged deterioration of the detection electrodes
Solution Approach 1:
The patent applies parameter changes by adjusting the driving signal voltage amplitude and detection time based on the signal difference between two detection signals acquired with different driving signal amplitudes. When the signal difference falls within a predetermined range, the system increases the driving signal voltage amplitude and/or detection time to compensate for electrode deterioration, thereby maintaining detection sensitivity without requiring electrode replacement.
2Measurement precision
If the driving signal voltage is increased to compensate for electrode deterioration, then detection sensitivity is maintained, but energy consumption increases
Solution Approach 1:
The patent implements dynamics by making the driving signal voltage amplitude and detection time adjustable rather than fixed. The system dynamically changes these parameters based on real-time detection of signal differences, increasing power only when electrode deterioration is detected and maintaining normal operation otherwise, thus optimizing energy consumption while preserving detection capability.
Solution Approach 2:
The system changes operational parameters (voltage amplitude and detection time) based on detected signal characteristics. By adjusting these parameters dynamically rather than maintaining constant high values, the system reduces overall energy consumption while compensating for electrode deterioration only when necessary.
3Measurement precision
If the detection time is increased to improve signal acquisition, then detection sensitivity is maintained, but response time and productivity decrease
Solution Approach 1:
The detection time is made dynamic rather than static. The system adjusts detection time based on the signal difference between two detection signals, extending it only when electrode deterioration is detected. This dynamic adjustment maintains detection sensitivity when needed while preserving fast response times during normal operation, thus resolving the contradiction between sensitivity and productivity.
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
The solution effectively suppresses the deterioration of detection sensitivity in touch panel-integrated display devices, ensuring consistent and accurate touch position detection.
Implementation Method 1
In the touch panel of the capacitance type, scanning electrodes (Y electrodes) for driving signal application arranged in a two-dimensional matrix shape lengthwise and crosswise and detection electrodes (X electrodes) for signal detection orthogonal to the scanning electrodes are provided. An input processing unit detects capacitances of the electrodes. When a conductor such as a finger comes into contact with the surface of the touch panel, the capacitances of the electrodes increase.
Data Source
AI summary
A display device includes a display panel and a touch panel built in the display panel. The touch panel includes a sensitivity correcting unit configured to correct the sensitivity of the touch panel. The sensitivity correcting unit includes a difference acquiring unit configured to acquire a signal difference (S1−S2) between a detection signal S1 acquired by detection electrodes when a driving signal V1 is input to scanning electrodes from a driving-signal supplying unit and a detection signal S2 (S1>S2) acquired by the detection electrodes when a driving signal V2 (V1>V2) different from the driving signal V1 is input to the scanning electrodes from the driving-signal supplying unit and a parameter changing unit configured to change parameters of at least one of the driving-signal supplying unit and a detecting unit when the signal difference (S1−S2) is equal to or smaller than a predetermined threshold.