In-Cell Touch Panel Scanning Layout for Higher Refresh Rates
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing in-cell touch panels face challenges in achieving higher refresh rates due to the prolonged time required for switching between display and touch sensing modes, which limits the operational efficiency.
Innovation Solution
The implementation of a first and second scanning line driving circuit, along with a control circuit that performs separate scanning operations for different scanning line groups, allowing for simultaneous display driving and touch detection without interrupting the scanning process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the in-cell touch panel alternates between display mode and touch sensing mode multiple times within one frame period, then the touch detection precision is improved, but the total switching time is prolonged and the refresh rate is reduced
Solution Approach 1:
The gate driver circuit is divided into multiple independent driving circuits (first gate driver circuit and second gate driver circuit), each responsible for different scanning line groups. This segmentation allows parallel operation of display scanning and touch detection without requiring frequent mode switching, thereby maintaining high touch detection precision while improving refresh rate.
2Measurement precision
If the number of switching operations between display mode and touch sensing mode is increased, then the touch detection accuracy is enhanced, but the time required for switching operations is prolonged
Solution Approach 1:
The patent enables continuous scanning operation by having multiple gate driver circuits work in parallel. While one scanning line group is being scanned for display, another group can simultaneously perform touch detection, eliminating the need to stop scanning for mode switching and thus reducing switching time loss.
3Device complexity
If a single scanning line driving circuit is used to supply display driving signals, then the device complexity is reduced, but the switching time between display and touch modes is prolonged
Solution Approach 1:
The single scanning line driving circuit is segmented into multiple independent gate driver circuits, each handling specific scanning line groups. This segmentation increases device complexity slightly but dramatically reduces switching time by enabling parallel operation, as the time benefit far outweighs the moderate increase in circuit count.
Data Source
AI summary
An in-cell touch panel includes a first scanning line driving circuit that supplies a display driving signal to a first scanning line group among multiple scanning lines; a second scanning line driving circuit that supplies a display driving signal to a second scanning line group among the scanning lines; a touch detection circuit that detects a touch by a pointer by acquiring a detection signal from at least a subset among multiple touch detection electrodes; and a control circuit. The control circuit performs a first scanning operation to supply the display driving signal to the first scanning line group, a touch detection operation after the first scanning operation to detect the touch with the touch detection circuit, a second scanning operation to supply the display driving signal to the second scanning line group, and the touch detection operation after the second scanning operation.