Pixel Circuit Touch Sensing via Piezoresistive Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current display apparatuses face challenges in integrating high-resolution touch sensing and image display functions while minimizing manufacturing costs, particularly due to the limited space for embedding separate touch sensors within the pixel unit.
Innovation Solution
The display apparatus employs a pixel circuit with a pressure resistance layer and transistors that switch between display and sensing modes, using a first current path for image display and a second current path to measure pressure resistance changes, allowing for simultaneous high-resolution image display and touch sensing without a separate touch sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a separate touch sensor is embedded inside the panel, then touch sensing function is achieved, but manufacturing cost increases and space is consumed
Solution Approach 1:
The patent merges the touch sensing function with the existing pixel circuit by utilizing the transistor structure already present in the display panel. The active layer of the transistor serves dual purposes: as a channel for display current and as a pressure-sensitive element for touch sensing, eliminating the need for a separate touch sensor layer
Solution Approach 2:
The transistor in the pixel circuit is designed to perform multiple functions: it serves as the switching element for display operation and simultaneously acts as the pressure sensor for touch detection. The same active layer conducts display current and detects pressure-induced resistance changes, achieving multi-functionality without additional components
2Adaptability or versatility
If a separate touch sensor is embedded inside the panel, then touch sensing function is achieved, but the area of the pixel unit is reduced
Solution Approach 1:
The touch sensing function is merged into the existing pixel circuit structure, specifically utilizing the transistor's active layer. This integration means no additional space is required beyond what is already allocated for the pixel circuit, preserving the pixel unit area while adding touch sensing capability
Solution Approach 2:
The transistor structure serves dual purposes: display operation and touch sensing. By making the same component perform both functions, the patent avoids the space that would be required for a separate touch sensor layer, thereby maintaining the pixel unit area
3Illumination intensity
If the pixel circuit uses a transistor for display, then image display is achieved, but the transistor cannot simultaneously serve as pressure sensor
Solution Approach 1:
The patent designs the transistor to perform both display and sensing functions. The active layer serves as the current channel for display operation while simultaneously acting as the pressure-sensitive element. When pressure is applied, the resistance of the active layer changes, which can be detected to determine touch occurrence and location
Solution Approach 2:
The patent utilizes the change in electrical resistance of the transistor's active layer under pressure as the sensing mechanism. During display operation, the transistor conducts current normally; during sensing mode, pressure-induced resistance changes in the same active layer are measured to detect touch events, allowing the same component to serve both purposes through parameter changes
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 approach enables parallel operation of display and sensing functions at low cost, reducing the need for additional sensors and minimizing space requirements, thus enhancing the display's functionality and cost-effectiveness.
Implementation Method 1
a second current path, configured to measure a resistance of a pressure resistance layer between the first signal line and the second signal line, is formed in the pixel circuit during the sensing mode
Data Source
AI summary
A display apparatus and driving method are provided. The display apparatus, which operates in a display mode or a sensing mode, includes: a first signal line configured to apply a first driving signal to a pixel circuit during the display mode and to apply a sensing input signal to the pixel circuit during the sensing mode; a second signal line configured to apply a second driving signal to the pixel circuit during the display mode and to transfer a sensing output signal from the pixel circuit during the sensing mode; and a pixel including the pixel circuit, wherein a first current path for image display is formed in the pixel circuit during the display mode, and a second current path, configured to measure a resistance of a pressure resistance layer between the first signal line and the second signal line, is formed in the pixel circuit during the sensing mode.