Touch Panel Detection Circuit for Approach and Coordinate Sensing
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Solution Overview
Problem
Touch panel-integrated display devices face challenges in detecting the approach of a user's finger without coordinate information, as existing detection circuits are primarily designed for mutual detection using electrostatic capacity changes between electrodes.
Innovation Solution
The implementation of a detection circuit that utilizes a drive signal supply unit with switching elements to differentiate between touch position detection and approach detection, allowing the same circuit to perform both mutual and self-detection by varying the voltage levels and switching states across scanning and detection electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the detection circuit is designed for mutual detection using electrostatic capacity changes between scanning electrodes and detection electrodes, then high-precision coordinate detection is achieved, but the circuit cannot detect the approach of a detection object without coordinate information
Solution Approach 1:
The patent makes the detection circuit perform both mutual detection (for coordinate detection) and self-detection (for approach detection) by configuring the scanning electrodes to be capable of both mutual capacity detection and self-capacity detection. The circuit structure is designed to support both detection modes using the same scanning electrodes and detection circuitry, thereby achieving multi-functionality without requiring separate dedicated circuits for each detection type.
2Adaptability or versatility
If separate detection circuits are provided for mutual detection and self-detection, then both detection functions are achieved, but device complexity increases
Solution Approach 1:
The patent employs a single detection circuit that can operate in both mutual detection mode and self-detection mode. The scanning electrodes are configured to enable both detection types, and the detection circuit is designed to handle both detection modes, thereby avoiding the need for separate dedicated circuits and reducing overall device complexity while maintaining full detection functionality.
Solution Approach 2:
The patent merges the mutual detection function and self-detection function into a single integrated detection circuit. By combining both detection capabilities into one circuit system that shares common components (scanning electrodes, detection circuitry), the patent reduces the total number of components and simplifies the overall device structure while achieving versatile detection functionality.
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
Enables the detection circuit to effectively detect the presence or absence of a user's finger approaching the touch panel, enhancing the precision and functionality of touch panel-integrated display devices by repurposing the detection circuit for self-detection tasks.
Implementation Method 1
detecting the presence or absence of the approach of the detection object without coordinate information (hereinafter, also referred to as a self detection) which uses a change of an earth capacity of the detection electrode due to the influence of a finger of a user
Implementation Method 2
performing the high-precision coordinate detection (hereinafter, also referred to as a mutual detection) which uses the change of the electrostatic capacity between the common electrode and the detection electrode due to the influence of a finger of a user
Data Source
AI summary
A display device includes a display panel, a touch panel control unit, a plurality of scanning electrodes formed on the display panel, a plurality of detection electrodes formed on the display panel so as to intersect with the plurality of scanning electrodes, a drive signal supply unit for inputting a drive signal to each of the scanning electrodes, and a detection unit for detecting a detection signal from each of the detection electrodes. The touch panel control unit supplies the driving signal to each of the scanning electrodes from the drive signal supply unit to enable detection of a touch position of a detection object based on the detection signal detected, and supplies the driving signal to all of the scanning electrodes collectively from the drive signal supply unit to enable detection of approach of the detection object to the touch panel based on the detection signal detected.