Patterned Polarizing Layer for Electroluminescent Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional self-light emitting display devices using inorganic EL or organic EL elements suffer from low light utilization efficiency due to the absorption of light by the circularly polarizing plate used as an antireflection film, which compromises the performance of light emitting elements.
Innovation Solution
An electroluminescent display device is designed with a patterned polarizing layer having regions of different polarization degrees, where the region with lower polarization corresponds to the light emitting elements, allowing for improved light transmission and reduced reflection of external light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a circularly polarizing plate consisting of a polarizer and a λ/4 plate is used as an antireflection film, then external light reflection is prevented and image display with high contrast is realized, but light emitted from the light emitting element is absorbed and light utilization efficiency is low
Solution Approach 1:
The polarizing plate is divided into a patterned structure with first regions (low polarization degree) positioned over light emitting elements and second regions (high polarization degree) positioned between adjacent light emitting elements. This segmentation allows different regions to perform different functions: the first regions transmit light from the light emitting elements with minimal absorption, while the second regions prevent reflection of external light.
Solution Approach 2:
Different regions of the polarizing plate are assigned different polarization degrees based on their functional requirements. The first regions have low polarization degree (0-30%) to maximize light transmission from the light emitting elements, while the second regions have high polarization degree (70-90%) to effectively prevent external light reflection. This local differentiation resolves the contradiction between light transmission and reflection prevention.
2Object-affected harmful factors
If a conventional polarizing plate with uniform high polarization degree is used, then external light reflection is effectively prevented, but light transmission from the light emitting element is reduced
Solution Approach 1:
The polarizing plate is segmented into functionally distinct first regions and second regions. The first regions are positioned to correspond to the light emitting elements and have low polarization degree to maximize light transmission, while the second regions are positioned between adjacent light emitting elements and have high polarization degree to prevent external light reflection.
Solution Approach 2:
The polarization degree is locally optimized for each region: first regions have polarization degree of 0-30% for maximum light transmission from the light emitting elements, while second regions have polarization degree of 70-90% for effective external light reflection prevention. This local quality differentiation resolves the contradiction between light transmission and reflection prevention.
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 light utilization efficiency while maintaining the ability to prevent external light reflection, thereby improving the overall performance of the display device.
Implementation Method 1
the patterned polarizing layer has a region A having a polarization degree of less than 80% and a region B having a polarization degree of 80% or more
Implementation Method 2
a 7.14 wavelength plate
Implementation Method 3
an electroluminescent substrate having a plurality of light emitting elements using electroluminescence
Data Source
AI summary
An object of the present invention is to provide a display device capable of achieving both an effect of preventing reflection of external light and improvement in utilization efficiency of light emitted from a light emitting element. An electroluminescent display device includes a substrate having a plurality of light emitting elements using electroluminescence, a λ/4 wavelength plate, and a polarizing plate including a patterned polarizing layer in this order, in which the patterned polarizing layer has a region A having a polarization degree of less than 80% and a region B having a polarization degree of 80% or more, and further, a position of the region A of the patterned polarizing layer corresponds to a position of the light emitting element of the electroluminescent substrate.