Electrophoretic Touch Panel Segmentation for Multiple-Coordinate Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing touch panels with electrophoretic display sections cannot detect multiple touch coordinates simultaneously.
Innovation Solution
A touch panel built-in display device with a configuration that includes pixel electrodes, a counter electrode, an electrophoretic display section, and detection electrode pairs, along with a touch coordinate detection circuit that calculates touch coordinates using voltage values and resistance ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a touch panel uses an electrophoretic display section with a transparent electrode and back electrode for display, then the display function is achieved, but the ability to detect multiple touch coordinates simultaneously is lost
Solution Approach 1:
The back electrode is segmented into multiple detection electrode pairs (first detection electrode and second detection electrode) arranged in different directions. Each detection electrode pair can independently detect touch signals, enabling the system to detect multiple touch coordinates simultaneously while maintaining the electrophoretic display structure.
Solution Approach 2:
Detection electrodes are arranged in multiple directions (first direction and second direction crossing the first direction) to add spatial dimensions to touch detection. This multi-directional arrangement allows the system to detect touch coordinates in both horizontal and vertical directions, enabling multi-point touch detection.
2Measurement precision
If the touch panel uses capacitance change detection at four corners to detect touch, then the detection method is simple, but only single contact position can be detected
Solution Approach 1:
The detection system is segmented into multiple detection electrode pairs that can independently measure capacitance changes at different locations. This segmentation allows simultaneous detection of multiple touch points without requiring sequential scanning, maintaining high detection speed while improving measurement precision.
Solution Approach 2:
The touch coordinate detection circuit continuously monitors capacitance changes across all detection electrode pairs and uses the distribution of capacitance changes to calculate precise touch coordinates. The feedback mechanism allows real-time detection and calculation of multiple touch positions simultaneously.
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 of multiple touch coordinates by determining the presence and calculating the coordinates of multiple touches on the touch panel.
Implementation Method 1
an electrophoretic display section (30) that includes charged particles (32a, 32b) arranged between the plurality of pixel electrodes (11) and the counter electrode (21)
Implementation Method 2
a position detection section that detects a contact position based on a change in the capacitance of the transparent electrode
Data Source
AI summary
A touch panel built-in display device comprises a touch coordinate detection circuit. The touch coordinate detection circuit, as to each detection electrode pair, determines presence or absence of a touch by a pointer at a coordinate in a second direction where the detection electrode pair is positioned, based on a total value or a difference value of a detection values of the detection electrode pair, and when determining that a touch is present, calculates a coordinate in the first direction of the touch by the pointer, based on a ratio of a detection value of a first detection electrode of the detection electrode pair at which a touch is determined to be present with respect to the total value of the detection electrode pair.