Circularly Polarized OLED Structure With Chiral Reflection Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OLED display technologies suffer from reduced light emission efficiency due to inevitable light loss through circular polarizers, which also shorten the display's lifetime and make it difficult to achieve perfect black display.
Innovation Solution
A circularly polarized light emitting display device is designed with a selective reflection layer having a chiral optical structure that rotates incident light and includes a chiral layer between the light emitting element and circular polarization layer, allowing for efficient circular polarization by reflecting one direction and transmitting the opposite, thereby minimizing light loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional circular polarizer (linear polarizer + quarter wave plate) is used in OLED, then external light reflection is completely prevented, but light emission efficiency decreases to no more than 50%
Solution Approach 1:
The patent extracts and removes the linear polarizer from the conventional circular polarizer structure, keeping only the quarter wave plate (QWP) component. This extraction eliminates the primary source of light loss (the linear polarizer that blocks 50% of light) while retaining the circular polarization function needed to prevent external light reflection.
Solution Approach 2:
Instead of using the conventional approach of linear polarizer + QWP, the patent inverts the approach by using only the QWP component and positioning it to directly convert linearly polarized OLED light into circularly polarized light. This inversion eliminates the unnecessary linear polarizer layer that causes energy loss.
2Adaptability or versatility
If a linear polarizer is placed over the quarter wave plate to create circular polarization, then circular polarization is achieved, but light loss is inevitable and light emission efficiency decreases
Solution Approach 1:
The patent extracts only the essential QWP component needed for circular polarization, removing the redundant linear polarizer layer. The QWP alone is sufficient to convert the linearly polarized light from OLED into circularly polarized light, eliminating the 50% light loss caused by the linear polarizer.
Solution Approach 2:
The QWP is positioned to directly receive linearly polarized light from the OLED and self-convert it into circularly polarized light without requiring an additional linear polarizer layer. The system uses the OLED's own emitted light characteristics to achieve circular polarization efficiently.
3Object-affected harmful factors
If conventional circular polarizer structure is used, then external light reflection is blocked, but OLED lifetime is shortened due to luminance loss
Solution Approach 1:
By extracting and removing the linear polarizer component that causes 50% light loss, the patent reduces the overall luminance loss in the display system. This reduction in light loss directly translates to reduced stress on the OLED, thereby extending its operational lifetime while maintaining the external light reflection blocking capability through the QWP.
4Object-affected harmful factors
If a cross polarizer configuration is used to achieve perfect black display, then external light is completely prevented from reflection, but light emission efficiency is reduced to less than 50%
Solution Approach 1:
The patent extracts and eliminates the linear polarizer from the cross polarizer configuration, retaining only the QWP component. This extraction maintains the ability to prevent external light reflection while eliminating the 50% light loss that occurs when light passes through the linear polarizer, thereby significantly improving light emission efficiency.
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 device enhances light emission efficiency by up to twice that of conventional OLEDs, maintaining high luminance and preventing external light reflection without absorption loss, thus extending the display's lifetime and improving contrast.
Implementation Method 1
the selective reflection layer may have a twisted chiral structure, and may include a chiral optical structure having a pitch of several tens or hundreds of nm
Implementation Method 2
the chiral optical structure may have an optical effect of rotating incident light to the left or the right
Implementation Method 3
An OLED circular polarizer includes a linear polarizer and a quarter wave plate creating a phase retardation of one-fourth of a wavelength (λ) stacked together to convert linearly polarized light into right-handed circular polarized light (RCP) or left-handed circular polarized light (LCP)
Implementation Method 4
a light emitting element layer
Data Source
AI summary
Provided is a circularly polarized light emitting display device including: a reflecting electrode; a light emitting element layer; a circular polarization layer; and a selective reflection layer provided between the light emitting element layer and the circular polarization layer, at least part of which is configured to have the same or opposite direction of rotation as or to the circular polarization layer. The circularly polarized light emitting display device. The circularly polarized light emitting display device can completely prevent reflection of external incident light and prevent a decrease in the light emission efficiency of an OLED.