Segmented OLED Cathode and Anode Structure for Uniformity
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Solution Overview
Problem
AMOLED display panels face issues with non-uniform display brightness and afterimages due to organic material degradation, where different colors degrade at different rates, and the difficulty in controlling uniformity of light-emitting layers and drive transistor film structures, leading to blurred images at low grayscale.
Innovation Solution
A light-emitting device with a cathode and anode divided into sub-cathodes and sub-anodes, allowing for intermittent driving of light-emitting areas, slowing down degradation and enabling high, intermediate, and low brightness modes to maintain uniformity and prevent afterimages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If organic light-emitting materials are used in AMOLED display panels, then higher response speed and wider angle of view are achieved, but non-uniform display brightness and afterimages occur due to different degradation rates of different colors
Solution Approach 1:
The light-emitting device is divided into a first light-emitting device and a second light-emitting device, each with separate light-emitting layers emitting different colors. This segmentation allows independent control and compensation of each color channel, addressing the non-uniform degradation issue while maintaining the high response speed benefits of organic materials
Solution Approach 2:
The patent employs drive circuits that can adjust driving parameters (current, voltage, pulse width) for each light-emitting device independently. By changing these parameters dynamically, the system compensates for degradation differences between colors, maintaining display uniformity while preserving the fast response characteristics
2Manufacturing precision
If light-emitting layers and drive transistor film structures are controlled for uniformity, then display consistency is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of controlling a single complex multi-layer structure for uniformity, the patent segments the light-emitting system into separate devices for different colors. Each segment has its own simpler light-emitting layer and drive circuit, reducing the overall manufacturing complexity while achieving uniformity through independent optimization
Solution Approach 2:
The patent uses a dual-emission approach where the light-emitting layers can emit different colors (e.g., blue and yellow-green) that combine to produce white light. This multi-functional design simplifies the need for precise control of complex color-filtering structures, reducing manufacturing complexity while maintaining display consistency
3Use of energy by moving object
If drive current is reduced for low grayscale display, then energy consumption is lowered, but image clarity deteriorates due to blurred images
Solution Approach 1:
The patent employs pulse-width modulation (PWM) or similar periodic driving techniques where the light-emitting devices are switched on and off at high frequencies. By controlling the duty cycle of these periodic pulses, the system achieves low grayscale levels with reduced average current consumption while maintaining sharp image edges through the inherent switching characteristics of the organic light-emitting devices
Solution Approach 2:
The drive circuits dynamically adjust the driving current and pulse characteristics based on the desired grayscale level. For low grayscale displays, the system uses short, precise current pulses rather than continuous low current, maintaining image sharpness while minimizing energy consumption through dynamic control
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 prolongs the service lifetime of the light-emitting device, reduces non-uniformity, and prevents afterimages by controlling light-emitting areas to emit light at different brightness levels, ensuring consistent image display across various grayscale levels.
Implementation Method 1
a light-emitting device including: a cathode, an anode and a light-emitting layer
Data Source
AI summary
The disclosure discloses a light-emitting device, a pixel circuit, a method for controlling the pixel circuit, an array substrate and a display device, where the light-emitting device includes a cathode, an anode and a light-emitting layer, where: the cathode includes a first sub-cathode and a second sub-cathode, both of which are arranged at a same layer; the anode includes a sub-anode and a second sub-anode, both of which are arranged at a same layer; and the light-emitting layer is located between the cathode and the anode.