Optical Film Group for OLED Display Contrast
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Organic light-emitting diode (OLED) display devices face reduced contrast due to ambient light reflection from structures within the panel, which mixes with emitted light, degrading image quality.
Innovation Solution
A display assembly comprising a display panel with an optical film group that includes a quarter-wave plate, a reflective polarizer, and an absorbing polarizer, where the reflective polarizer allows light parallel to its axis to pass through and reflects light perpendicular to its axis, and the absorbing polarizer allows light parallel to its axis to pass through while absorbing light perpendicular to its axis, effectively reducing ambient light interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional display panel structure is used, then the structure is simple and manufacturing is easy, but ambient light reflection reduces contrast and degrades image quality
Solution Approach 1:
The optical film group is segmented into three distinct functional layers: quarter-wave plate, reflective polarizer, and absorbing polarizer. Each layer performs a specific function in managing light polarization and reflection, allowing the system to address ambient light reflection without requiring complete structural redesign of the entire display panel.
Solution Approach 2:
The optical film group acts as an intermediary layer between the display panel and ambient light. The quarter-wave plate converts linearly polarized light to circularly polarized light, the reflective polarizer reflects specific polarization directions, and the absorbing polarizer absorbs remaining unwanted light, collectively eliminating ambient light reflection interference.
2Object-affected harmful factors
If optical compensation films are added to improve viewing angle and reduce reflection, then image quality improves, but the number of layers increases and manufacturing complexity increases
Solution Approach 1:
Multiple optical functions (viewing angle compensation, reflection reduction, polarization control) are merged into a single integrated optical film group structure. The quarter-wave plate, reflective polarizer, and absorbing polarizer work together in one compact assembly, eliminating the need for separate compensation films and reducing overall structural complexity.
Solution Approach 2:
The optical film group performs multiple functions simultaneously: the quarter-wave plate addresses viewing angle issues, the reflective polarizer reduces ambient light reflection, and the absorbing polarizer enhances contrast. This multi-functional design replaces what would traditionally require multiple separate components.
3Object-affected harmful factors
If the reflective polarizer area is increased to cover non-light-emitting areas, then ambient light reflection is reduced, but light output from the display may be blocked
Solution Approach 1:
The reflective polarizer is applied with spatially varying properties: it covers non-light-emitting areas (pixel electrodes, transparent conductive oxide layers, encapsulation layers) to reflect ambient light, while allowing light-emitting areas (organic light-emitting diodes) to transmit display light. This localized application ensures reflection reduction without blocking display output.
Solution Approach 2:
Instead of trying to prevent ambient light from entering the display panel, the invention inverts the approach by allowing ambient light to pass through the display panel and then reflecting it back using the optical film group. The quarter-wave plate converts polarization states, and the reflective polarizer reflects the converted light away, achieving reflection reduction without blocking the display light path.
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
This configuration enhances contrast by minimizing ambient light reflection and increasing light output from the display assembly, thereby improving image quality.
Implementation Method 1
a quarter-wave plate, a reflective polarizer and an absorbing polarizer arranged sequentially along a thickness direction of the display panel
Implementation Method 2
The reflective polarizer includes a reflective portion capable of allowing light with a polarization direction parallel to a polarization axis of the reflective polarizer to pass through and reflecting light with a polarization direction perpendicular to the polarization axis of the reflective polarizer
Implementation Method 3
The absorbing polarizer is capable of allowing light with a polarization direction parallel to a polarization axis of the absorbing polarizer to pass through and absorbing light with a polarization direction perpendicular to the polarization axis of the absorbing polarizer
Data Source
AI summary
A display assembly includes a display panel and at least one optical film group each disposed on a display surface. Each optical film group includes a quarter-wave plate, a reflective polarizer and an absorbing polarizer. The reflective polarizer includes a reflective portion capable of allowing light with a polarization direction parallel to a polarization axis of the reflective polarizer to pass through and reflecting light with a polarization direction perpendicular to the polarization axis. An orthographic projection of an effective light-emitting area of at least one sub-pixel is substantially within an orthographic projection of the reflective portion. The absorbing polarizer is capable of allowing light with a polarization direction parallel to a polarization axis of the absorbing polarizer to pass through and absorbing light with a polarization direction perpendicular to the polarization axis. The polarization axis of the reflective polarizer is parallel to the polarization axis of the absorbing polarizer.