OLED Display Polarizer Structure for Thin Flexible Design
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Solution Overview
Problem
Existing organic electroluminescent displays (OLEDs) face issues with low transmittance, thick film structures, and difficulty in rolling due to complex and thick circular sheet polarizers, which compromise contrast and durability.
Innovation Solution
An OLED display structure incorporating a phase difference film and a polarization functional film, attached in a vacuum or inert gas environment, replaces the traditional circular sheet polarizer, reducing thickness and improving transmittance and durability by eliminating unnecessary films and protecting against aqueous vapor and oxygen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a traditional circular sheet polarizer is used in OLED display, then the display structure is complete and contrast is improved, but the film thickness becomes large (above 200 μm) and transmittance is low
Solution Approach 1:
The traditional circular sheet polarizer is segmented into separate functional films: a polarization film (PVA) and a phase difference film. These films are attached independently to the OLED display in sequence, allowing each film to be optimized for its specific function rather than being bundled together in a thick composite structure.
Solution Approach 2:
The invention transitions from a three-dimensional thick composite polarizer structure to a two-dimensional layered film structure attached directly to the display surface. This dimensional change allows for reduced overall thickness while maintaining the polarizing and phase difference functions through proper material selection and layer arrangement.
2Reliability
If a traditional circular sheet polarizer with multiple protective layers is used, then the PVA layer is protected from hydrolysis, but the structure becomes complex and the number of films increases
Solution Approach 1:
The PVA polarization film is protected from hydrolysis by attaching it in a vacuum or inert gas environment, and by using a release film with low water vapor transmission rate. This eliminates the need for multiple protective layers (TAC films, binding agent layers) that would otherwise be required to prevent water ingress, thereby simplifying the overall structure.
Solution Approach 2:
The invention extracts and removes unnecessary protective layers and binding agents from the traditional circular sheet polarizer structure. By using a release film that provides both protection and easy release functionality, multiple layers are consolidated into a single functional component.
3Ease of manufacture
If multiple films and binding agent layers are used in circular sheet polarizer, then the PVA layer and quarter-wavelength plate are attached together, but the manufacturing process becomes complex
Solution Approach 1:
The release film serves multiple functions simultaneously: it protects the PVA layer during storage and transport, provides a release surface for easy detachment, and can be removed without leaving residue. This multi-functionality eliminates the need for separate protective films and binding agents, simplifying the manufacturing process.
Solution Approach 2:
The release film is pre-attached to the PVA layer during the polarization process, and the entire assembly is stored with the release film in place. This preliminary action protects the PVA layer from hydrolysis during storage and simplifies the final attachment process, as the release film is already positioned and ready for controlled removal.
4Illumination intensity
If a thick circular sheet polarizer is attached to OLED display, then the display is protected from light reflection, but the display becomes difficult to roll and flexibility is reduced
Solution Approach 1:
The invention uses thin flexible films (PVA polarization film and phase difference film) that can be directly attached to the OLED display. These thin films maintain the contrast-improving function while allowing the display to be flexible and easily rolled, unlike thick rigid circular sheet polarizers.
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 transmittance, contrast, and reduces overall thickness, making OLED displays lighter, thinner, and easier to roll, while increasing durability by preventing aqueous vapor and oxygen interference.
Implementation Method 1
The circular sheet polarizer changes the polarized state of an incident light to make it unable to emerge, thus the contrast can be improved
Implementation Method 2
The luminescence of an OLED display is realized by exciting an organic material in a luminescent layer to emit light when the electrons in the cathode and the holes in the anode recombine in the luminescent layer
Data Source
AI summary
Disclosed are an organic electroluminescent display and a method for preparing the same, and a display device. The organic electroluminescent display comprises: a base substrate; an organic electroluminescent pixel array, which is set on the base substrate; a packaging coverplate or a packaging film, which is covered outside the organic electroluminescent pixel array; and a phase difference film and a polarization functional film located inside the packaging coverplate or the packaging film and attached to the organic electroluminescent pixel array in turn. In the organic electroluminescent display according to the invention, the unnecessary films, such as a TAC films that need to be attached to the two sides of a polarization functional film in an existing circular sheet polarizer and a binding agent layer, etc., can be omitted, thereby the transmittance of a display can be improved, and the contrast of a display can be increased; moreover, the overall thickness of a display may be reduced, and the problem of being difficult to roll up may be avoided; and there exists no interference of oxygen and aqueous vapor, thus the durability of the circular sheet polarizer can be increased.