Touch Panel Baseline Update Control for Capacitance Detection
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Solution Overview
Problem
Existing touch panels using electrostatic capacitive sensors face challenges in detecting minute capacitance variations due to ambient temperature changes, leading to performance degradation and erroneous touch detection, especially during hover operations and steep temperature variations.
Innovation Solution
An electronic device with a touch panel equipped with electrostatic capacitive sensors, a measurement unit, a touch detection unit, a base line value update unit, and a control unit that dynamically adjusts the update speed of the base line value based on proximity detection, allowing for slow updates during object approach and fast updates when the object is not detected, thereby maintaining detection accuracy and recovery time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the base line value is updated continuously to follow temperature variations, then the correction of electrostatic capacitance variation is improved, but the detection of minute capacitance changes during hover is degraded
Solution Approach 1:
The patent applies dynamics by making the base line value update mechanism adaptive rather than static. The control unit dynamically adjusts whether to update the base line value based on real-time detection of object proximity. When an object is detected approaching the touch panel, the update is suppressed to maintain detection sensitivity. When no object is detected, the base line value is updated to track temperature variations. This dynamic switching resolves the contradiction between maintaining correction accuracy and preserving detection sensitivity.
2Measurement precision
If the base line value update is stopped during touch detection to maintain detection state, then the touch detection accuracy is improved, but the recovery time after touch release is increased
Solution Approach 1:
The patent implements periodic action by using distinct update cycles based on operational phases. During active touch detection, the base line value update is suspended (first period). After touch release, once a predetermined time elapses without detected touches, the update resumes (second period). This periodic switching between update suspension and resumption allows the system to maintain detection accuracy during critical touch periods while enabling recovery after touch release, resolving the time loss contradiction.
3Productivity
If the base line value is updated quickly to reduce recovery time, then the productivity is improved, but the detection precision during temperature transition is degraded
Solution Approach 1:
The patent applies parameter changes by modifying the update speed parameter of the base line value based on operational context. Instead of using a fixed update speed, the control unit adjusts the update parameter dynamically: during temperature transitions or when objects are detected, updates are suppressed or slowed to maintain precision; during stable periods after touch release, updates resume at normal speed to improve recovery. This contextual parameter adjustment resolves the contradiction between recovery speed and detection precision.
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 enhances the detection of minute capacitance variations and reduces recovery time for the base line value, improving hover performance and preventing erroneous touch detections by dynamically controlling the update speed based on object proximity.
Implementation Method 1
a plurality of electrostatic capacitive sensors which are disposed in the touch panel, and an electrostatic capacitance of the electrostatic capacitive sensor varies as an object comes close or comes into contact
Implementation Method 2
a measurement unit which measures the electrostatic capacitance of the electrostatic capacitive sensor
Data Source
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AI summary
Provided is a touch panel device which can detect a minute variation in capacitance while controlling an update speed of a base line value. A touch panel device (100) of the invention includes a touch panel (110) which is equipped with a plurality of electrostatic capacitive sensors of which the electrostatic capacitances vary as an object comes close or comes into contact, a measurement unit (120) which measures the electrostatic capacitance of the electrostatic capacitive sensor, a touch detection unit (130) which detects an object coming close or coming into contact on the basis of a difference between a measured raw value and the base line value, a base line value update unit (150) which updates the base line value to follow up the raw value of the electrostatic capacitance of the electrostatic capacitive sensor to correct a variance in electrostatic capacitance of the electrostatic capacitive sensor, a proximity detection unit (160) which detects an object approaching to the touch panel, and an update control unit (170) which controls the update speed on the basis of a detection result of the proximity detection unit (160).