Hybrid Touch Sensor System for Display Ghost Phenomenon
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Solution Overview
Problem
Existing display devices with touch sensors face challenges in accurately detecting touch inputs, particularly in preventing misrecognition of multi-touch inputs due to the 'ghost phenomenon' and achieving high sensitivity, which affects the reliability and precision of touch detection.
Innovation Solution
A display device incorporating a hybrid touch sensor system with a self-capacitance type first touch sensor and a light-sensing type second touch sensor, where the driving circuit compares touch detection values from both sensors to accurately detect touch inputs, and photo sensors are strategically placed between pixels to enhance sensitivity and reduce misrecognition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single touch sensor type is used, then the device structure is simple, but touch detection sensitivity and accuracy deteriorate due to ghost phenomenon in multi-touch detection
Solution Approach 1:
The patent combines two different touch sensor types (self-capacitance touch sensor and photo sensor) into a single hybrid touch detection system. The self-capacitance touch sensor detects touch position through capacitance changes, while the photo sensor detects touch through light blocking effects. By merging these two sensor types and comparing their detection results, the system achieves high accuracy in multi-touch detection without suffering from the ghost phenomenon that plagues single-type touch sensors.
2Reliability
If photo sensors are disposed between pixels, then touch sensitivity is improved, but the display area is reduced
Solution Approach 1:
The patent places photo sensors specifically in the black matrix regions between pixels rather than uniformly across the entire display area. The black matrix regions are areas where light blocking occurs naturally, so placing photo sensors there allows touch detection without significantly reducing the light-emitting display area. This localized placement strategy maintains high touch sensitivity while preserving maximum display area.
3Measurement precision
If hybrid touch sensor system is implemented, then misrecognition of multi-touch inputs is prevented, but manufacturing complexity increases
Solution Approach 1:
The patent designs the photo sensors to serve dual functions: they act as touch sensors for detecting finger touches through light blocking, and simultaneously function as ambient light sensors for display brightness adjustment. This multi-functionality reduces the need for separate sensor components, simplifying the overall manufacturing process while maintaining high touch detection precision and preventing multi-touch misrecognition.
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 prevents misrecognition of multi-touch inputs and improves touch sensitivity, allowing for precise detection of touch events while maintaining high sensitivity characteristics.
Implementation Method 1
a second touch sensor including photo sensors disposed between the pixels or in the pixels; and a driving circuit configured to drive the first touch sensor and the display panel, wherein the driving circuit may be configured to detect a touch input by comparing a first touch detection value detected by the first touch sensor and a second touch detection value detected by the photo sensors
Data Source
AI summary
A display device may include: a first touch sensor including first sensing electrodes and second sensing electrodes, arranged in a sensing area intersecting each other; a display panel including: pixels arranged in a display area overlapping with the sensing area; and a second touch sensor including photo sensors disposed between the pixels or in the pixels; and a driving circuit configured to drive the first touch sensor and the display panel, wherein the driving circuit may be configured to detect a touch input by comparing a first touch detection value detected by the first touch sensor and a second touch detection value detected by the photo sensors.