OLED Display Panel Recessed Layer to Reduce Total Reflection
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Solution Overview
Problem
OLED display apparatuses suffer from low light emitting efficiency due to total reflection of light at the interface between organic film layers and air, resulting in only 20% of emitted light being emitted into the air, while 80% is lost.
Innovation Solution
A display panel design featuring a first defining layer and a recessed first layer on a base substrate, which changes the incident angle and propagation path of light emitted by sub-pixels, reducing total reflection and increasing light emission efficiency, optionally using a reflective material for the recessed layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If light is emitted from OLED sub-pixels through flat organic film layers, then the structure is simple and easy to manufacture, but total reflection occurs at the interface between organic film layers and air, causing 80% of light to be lost
Solution Approach 1:
The patent introduces a third dimension by creating a recessed structure in the organic film layer, transforming the flat two-dimensional interface into a three-dimensional micro-cavity structure. This dimensional change allows light to escape through the recessed region where the escape angle condition is satisfied, thereby improving light extraction efficiency without fundamentally changing the material composition
Solution Approach 2:
The recessed surface of the organic film layer is designed with a curved or inclined shape rather than a flat surface. This curvature changes the propagation path of light emitted from the sub-pixels, allowing light to meet the escape angle condition more effectively and reduce total internal reflection at the organic film-air interface
2Loss of energy
If a recessed structure is introduced to improve light emission efficiency, then light extraction efficiency increases, but the manufacturing process becomes more complex
Solution Approach 1:
The patent combines the recessed structure formation with the existing organic film deposition process. The recessed region is formed by controlling the deposition process or by selective removal, merging the light extraction enhancement feature with the standard OLED manufacturing流程, thereby reducing the need for separate complex manufacturing steps
Solution Approach 2:
The patent changes the geometric parameters of the organic film layer by creating a recessed region with specific depth, width, and curvature. These parameter changes are optimized to maximize light extraction efficiency while remaining compatible with existing manufacturing capabilities, balancing performance improvement with manufacturing ease
3Illumination intensity
If the recessed layer uses reflective material to redirect light, then light output efficiency improves, but the material selection and layer design become more complex
Solution Approach 1:
The patent converts the harmful effect of total internal reflection into a beneficial effect by using reflective material in the recessed region. Light that would normally be trapped by total reflection is instead redirected by the reflective surface toward the escape angle region, converting energy loss into useful light output and improving overall extraction efficiency
Solution Approach 2:
The reflective material in the recessed region acts as an intermediary between the sub-pixel light source and the external environment. It mediates the light propagation by redirecting trapped light toward escape paths, serving as an intermediate optical element that enhances light extraction without requiring fundamental changes to the OLED 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
The design enhances light emitting efficiency by reducing total reflection and crosstalk between sub-pixels, improving the display effect and light output from the OLED panel.
Implementation Method 1
OLED display apparatuses suffer from low light emitting efficiency due to total reflection of light at the interface between organic film layers and air
Implementation Method 2
changes the incident angle and propagation path of light emitted by sub-pixels
Implementation Method 3
optionally using a reflective material for the recessed layer
Data Source
AI summary
A display panel includes a first defining layer, a first recessed layer, a flat layer, and a pixel unit layer that are laminated on a base substrate in sequence. The pixel unit layer includes a plurality of sub-pixels. The first defining layer defines one or more defining regions on the base substrate, and the one or more defining regions corresponding to part or all of the plurality of sub-pixels. A surface of the first recessed layer in each defining region is recessed.