OLED Pixel Circuit With Integrated Touch Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In-cell touch screens have complex control circuits and manufacturing processes, leading to decreased production yield and efficiency, as well as reduced pixel aperture ratio and display quality.
Innovation Solution
An OLED pixel circuit with a simplified control circuit and manufacturing process, incorporating a data writing unit, driving unit, OLED, first and second control units, and a touch detecting unit, including a photodiode, which allows direct signal sensing and reduces the need for indium tin oxide films, improving light transmittance and display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If in-cell touch screen technology is implemented by embedding touchpad sensing function in pixel circuit, then touch sensitivity is improved, but device complexity and manufacturing complexity increase significantly
Solution Approach 1:
The pixel circuit is designed to perform both display function (driving OLED) and touch sensing function simultaneously. The same pixel circuit structure handles both the light-emitting control and the touch signal detection, eliminating the need for separate touchpad control circuits. This multi-functionality approach resolves the contradiction by integrating touch sensing into the existing display pixel circuit without adding separate control circuitry.
Solution Approach 2:
The touch sensing function is merged with the display pixel circuit by using shared components. The pixel circuit includes both OLED driving transistors and touch sensing transistors that operate within the same pixel structure. This merging combines the touchpad sensing function with the display function, reducing overall device complexity while maintaining touch sensitivity.
2Difficulty of detecting and measuring
If in-cell touch screen technology is implemented by embedding touchpad sensing function in pixel circuit, then touch sensitivity is improved, but manufacturing complexity increases
Solution Approach 1:
The manufacturing process merges the touch sensor layer with the OLED display layer. Both the touch sensing electrodes and OLED electrodes are formed using the same ITO layer deposition process. The pixel circuit manufacturing integrates touch transistor fabrication with OLED transistor fabrication in a unified process flow, reducing manufacturing steps and improving ease of production while enabling touch sensitivity.
3Difficulty of detecting and measuring
If in-cell touch screen technology is implemented, then touch sensitivity is improved, but pixel aperture ratio decreases
Solution Approach 1:
The touch sensing electrodes and OLED electrodes are merged into a single shared ITO layer. This integration eliminates the need for separate transparent electrode layers for touch sensing, reducing the non-active area in the pixel structure. By combining the electrical functions of both touch and display electrodes into one layer, the pixel aperture ratio is maximized while maintaining touch sensitivity.
4Difficulty of detecting and measuring
If multiple control circuits are added for in-cell touch functionality, then touch sensitivity is improved, but production efficiency decreases
Solution Approach 1:
The pixel circuit is designed as a universal circuit that handles both display control and touch sensing without requiring separate dedicated control circuits. The same scanning lines, data lines, and control signals are used for both OLED driving and touch signal acquisition. This multi-functionality eliminates the need for additional control circuitry that would slow down production and improve manufacturing efficiency while maintaining touch sensitivity.
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 enhances production efficiency and yield, reduces production costs, and improves picture uniformity and light transmittance, enabling thinner, lighter, and more sensitive touch-sensitive displays with improved display quality.
Implementation Method 1
the touch detecting unit comprises a photodiode... in the touch detecting stage, is used for sensing touch under the control of a touch signal level control line, and generating a detecting signal
Implementation Method 2
OLED, in the OLED light-emitting stage, is used for turning on the OLED and the driving unit
Data Source
AI summary
The present invention, provides an OLED pixel circuit, a driving method thereof and a display device. A first control unit of the OLED pixel circuit of the present invention is used for importing a power supply signal into a data writing unit and turning on an OLED and a driving unit; the data writing unit is used for importing a power supply voltage signal and a data line signal, and meanwhile for supplying voltage to the driving unit; a touch detecting unit is used for sensing touch and generating a detecting signal; the driving unit is used for converting the detecting signal into touch output signal which is output to a driving IC via the touch detecting unit and for providing drive current for the OLED; and a second control unit is used for connecting the driving unit to ground level.