Flexible OLED Panel Bending Detection Using Pixel Driving Circuits
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Solution Overview
Problem
Flexible organic light emitting display devices require additional bending sensors to determine bending, which complicates manufacturing, increases costs, and makes it difficult to produce narrow bezel devices.
Innovation Solution
Incorporating a pixel driving circuit that senses characteristic changes of driving transistors to determine panel bending, eliminating the need for separate bending sensors and allowing real-time deformation sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate bending sensors are mounted in the non-display area to check bending, then bending detection capability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the bending sensing function with the existing pixel driving circuit by integrating a sensing unit that shares signal lines (data lines and sensing lines) with the display pixels. The pixel driving circuit is modified to include sensing transistors that can detect bending-induced changes in transistor characteristics, eliminating the need for separate bending sensors and reducing device complexity while maintaining bending detection capability
Solution Approach 2:
The pixel driving circuit is designed to perform dual functions: driving pixels for display during normal operation and sensing bending through the sensing unit during blank periods. The same data lines and sensing lines are used for both display signal transmission and bending detection, making the circuit universal and multi-functional
2Measurement precision
If multiple bending sensors are provided to accurately sense deformation of the whole area, then measurement precision is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent implements self-service by using the existing pixel circuits and their driving transistors to sense bending. The sensing unit utilizes the inherent electrical characteristics of the pixel driving transistors, which naturally change when bent due to stress, eliminating the need for external sensing components and reducing manufacturing cost while maintaining full-area deformation sensing capability
3Measurement precision
If separate bending sensors are added to the display area to sense bending, then bending detection capability is improved, but device complexity increases
Solution Approach 1:
The patent merges the bending sensing function directly into the pixel driving circuit located in the display area. The sensing unit is integrated with the pixel circuits, allowing bending detection in the display area without adding separate sensors, thus improving detection capability while avoiding increased device complexity
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
Simplifies the manufacturing process, reduces costs, and enables accurate bending detection without additional sensors, facilitating various applications related to bending presence.
Implementation Method 1
a pixel driving circuit which senses characteristic changes of a driving transistor driving an organic light emitting diode
Data Source
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AI summary
The flexible organic light emitting display device includes a panel (100), a data driver (310) configured to drive data lines included in the panel, a gate driver (200) configured to drive gate lines included in the panel, a sensing unit (320), and a controller (400). The sensing unit senses bending of the panel in a blank period of one frame period by using a pixel driving circuit included in each of a plurality of pixels (110) included in the panel, for sensing a characteristic change of a driving transistor driving an organic light emitting diode included in each of the plurality of pixels, the one frame period including the blank period and a display period. The controller senses the characteristic change of the driving transistor or analyzes whether the panel is bent, based on pieces of sensing data transferred from the sensing unit.