OLED Pixel Drive Circuit Segmentation for Flicker Control
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Solution Overview
Problem
Conventional OLED display panels suffer from uneven brightness and screen flickering issues, particularly at low gray levels, due to non-uniformities in transistor electrical parameters, which are exacerbated by the PWM time-sharing driving method.
Innovation Solution
The OLED display panel is designed with a pixel drive circuit that includes a reset module, data signal input module, storage module, and drive module, where the pixel electrode is divided into two sub-pixel electrodes, allowing for different light emission scenarios in normal and low brightness modes using a time-sharing driving method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If PWM time-sharing driving method is used to reduce brightness of sub-pixels, then brightness uniformity is improved, but screen flicker occurs and improvement effect is insufficient
Solution Approach 1:
The pixel electrode is divided into two independent sub-pixel electrodes (first sub-pixel electrode and second sub-pixel electrode), each capable of being independently controlled to emit light. This segmentation allows the display to switch between different emission modes: both sub-pixels emitting together for normal brightness, or only one sub-pixel emitting for low brightness, thereby avoiding flicker while maintaining brightness uniformity.
2Illumination intensity
If drive current is reduced for low gray levels, then brightness is reduced, but Mura phenomenon becomes more serious
Solution Approach 1:
The invention implements dynamic switching between different light emission modes based on the required brightness level. For low gray levels, instead of reducing current (which exacerbates Mura), the system dynamically switches to a mode where only one sub-pixel electrode emits light, maintaining adequate current levels and thus preserving brightness uniformity while achieving the desired low brightness level.
3Device complexity
If single pixel electrode is used, then device complexity is low, but brightness uniformity and flicker control are insufficient
Solution Approach 1:
The pixel electrode is segmented into two sub-pixel electrodes with independent control capability. This segmentation enables sophisticated brightness control strategies: both sub-pixels can emit for normal brightness, or only one can emit for low brightness scenarios, thereby achieving superior brightness uniformity and flicker control while maintaining relatively simple overall device structure.
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 improves brightness uniformity and eliminates screen flickering, enhancing display quality by allowing optional light emission from sub-pixel areas based on brightness conditions.
Implementation Method 1
a light emitting device comprising a first light emitting device and a second light emitting device
Data Source
AI summary
An OLED display panel is provided. The OLED display panel includes a plurality of sub-pixels arranged in an array and a plurality of pixel drive circuits for driving the sub-pixels. At least one of the pixel drive circuits comprises a reset module, a data signal input module, a storage module, a light emitting device, and a drive module. The drive module drives a first light emitting device and a second light emitting device to emit light in a first display stage, and drives the first light emitting device to emit light in a second display stage, whereas the second light emitting device does not emit light.