Display Sensor Patterns for Stylus-Finger Detection at Screen Edges
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Solution Overview
Problem
Existing touch screens, particularly capacitive touch screens, struggle to distinguish between a finger and a stylus pen, leading to operational errors and sensitivity degradation at the edge portions of the display screen, often requiring additional sensor films and separate software for accurate input detection.
Innovation Solution
An electronic device design that integrates a sensor unit with overlapping patterns, including edge channels in the dead space, allowing for simultaneous sensing of a stylus pen and objects like fingers without the need for a separate digitizer, by using a controller to form current loops and magnetic fields for stylus pen detection, and improve sensitivity at edge areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a C-type touch screen is used to enable stylus pen recognition, then stylus pen detection capability is improved, but operational errors occur due to inability to distinguish between finger and stylus pen contact
Solution Approach 1:
The sensor unit is divided into multiple independent patterns (first pattern, second pattern, third pattern) with different electrical configurations. The first pattern has both ends connected to the controller, the second pattern has one end connected and the other end floating, and the third pattern has both ends connected but with different drive signal phases. This segmentation allows each pattern to serve a specific detection function, enabling the system to distinguish between finger and stylus pen contact based on the unique electrical response of each pattern segment.
Solution Approach 2:
Different regions of the sensor unit are assigned different electrical properties and detection functions. The first pattern region detects general touch, the second pattern region (with floating end) detects stylus pen contact through capacitive coupling, and the third pattern region detects touch position. This local differentiation of electrical characteristics enables the system to accurately identify the type of contact (finger vs. stylus) at different locations on the display surface.
2Adaptability or versatility
If a separate sensor film (digitizer) is added to detect stylus pen, then stylus pen sensing capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the touch sensing function and stylus pen detection function into a single integrated sensor unit that is part of the display panel structure. Instead of adding a separate digitizer layer, the sensor unit incorporates multiple patterns with different electrical configurations directly in the display panel, combining what would traditionally be separate components into one unified structure. This reduces device complexity while maintaining both touch and stylus detection capabilities.
Solution Approach 2:
The sensor unit performs multiple functions simultaneously: it detects general touch input, identifies stylus pen contact through capacitive coupling, and determines touch position. By making the sensor unit multi-functional, the patent eliminates the need for separate dedicated stylus detection hardware, thereby reducing overall device complexity while achieving comprehensive input detection.
3Area of stationary object
If sensor patterns are placed only within the active area, then display area utilization is improved, but sensitivity degradation occurs at edge portions of the display
Solution Approach 1:
The patent extends the sensor patterns from the traditional two-dimensional active area into the dead space region, creating a three-dimensional detection architecture. The first pattern extends into the dead space with both ends connected to the controller, while the second pattern has its floating end in the dead space. This dimensional extension allows the sensor to detect stylus pen contact at the edges of the display where the active area patterns alone would be insufficient, thereby improving sensitivity at edge portions without sacrificing display area utilization.
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 accurate and sensitive detection of both stylus pens and fingers without additional sensors, enhancing input accuracy and reducing sensitivity degradation at the edges of the display screen.
Implementation Method 1
a controller configured to control the sensor unit... the sensor unit includes an edge pattern that overlaps the dead space, is disposed adjacent to the active area, and has both ends electrically connected to the controller
Implementation Method 2
When a position of the stylus pen that generates a magnetic field is changed, a separate integrated circuit detects the change of the magnetic field generated by an interaction
Data Source
AI summary
The present disclosure relates to an electronic device, and more particularly, to an electronic device capable of simultaneously sensing a stylus pen and an object such as a finger brought into proximity or contact with the electronic device from the outside and capable of improving sensitivity degradation at an edge portion of an active arca of a display screen.