On-Cell Display Electrode Switching for Finger and EMR Pen Detection
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Solution Overview
Problem
Existing on-cell touch technologies face challenges in reducing bezel area size and circuit scale while detecting both finger and electromagnetic resonance stylus positions, and incur increased manufacturing costs due to the placement of switching circuits and drive circuits in non-display areas.
Innovation Solution
The display integrates switching circuits and drive circuits within the display layer, using MOSFETs of the same channel type, allowing for bezel area reduction and preventing circuit scale increase, while enabling simultaneous detection of finger and electromagnetic resonance stylus positions without additional cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If switching circuits are placed in the bezel area to detect both finger and electromagnetic resonance stylus positions, then detection capability is improved, but the bezel area size increases
Solution Approach 1:
The patent merges the switching circuits with the pixel drive circuits by integrating them into the same display layer. The switching circuits share the same TFT structure and fabrication process as the pixel drive circuits, allowing both detection functions (finger and electromagnetic resonance stylus) to be implemented without requiring separate bezel area for housing switching circuits.
2Adaptability or versatility
If switching circuits are integrated into the sensor controller to detect both input methods, then detection capability is improved, but the circuit scale of the sensor controller increases
Solution Approach 1:
The patent segments the detection functions by implementing switching circuits directly in the display layer that can independently switch between finger detection mode and electromagnetic resonance stylus detection mode. This segmentation allows the sensor controller to maintain a compact scale while the distributed switching circuits in the display layer handle the dual detection functions through time-division multiplexing.
3Adaptability or versatility
If drive circuits for linear electrodes are placed in the display layer using both P-channel and N-channel MOSFETs, then circuit functionality is improved, but manufacturing cost increases due to ion implantation process
Solution Approach 1:
The patent applies local quality by using P-channel MOSFETs specifically for the switching circuits while using N-channel MOSFETs for the pixel drive circuits. This localized assignment of MOSFET types allows both circuit functionalities to coexist in the display layer without requiring additional ion implantation processes, as each MOSFET type can be formed through separate fabrication steps optimized for their specific requirements.
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 configuration maintains bezel area reduction efforts and prevents circuit scale expansion, while effectively detecting both input methods without increasing manufacturing costs.
Implementation Method 1
a group of linear electrodes disposed on the encapsulation layer... in a first mode, the linear electrodes are used to detect induced currents
Implementation Method 2
in a second mode, the linear electrodes are used to detect capacitances
Data Source
AI summary
A display is provided which is capable of detecting positions of both a finger and an electromagnetic resonance pen. The display includes a display layer including a group of light-emitting elements disposed in a display area and a group of pixel drive circuits for turning on and off the light-emitting elements, an encapsulation layer encapsulating the display layer, a group of linear electrodes disposed on the encapsulation layer, and a group of routing paths having ends connected to the linear electrodes. A switching circuit is disposed in the display layer within the display area and is connected to other ends of the routing paths, for switching between a first mode in which the linear electrodes are used to detect induced currents and a second mode in which the linear electrodes are used to detect capacitances.