Peripheral OLED Substrate Light Outcoupling via Edge Geometry
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Solution Overview
Problem
Conventional organic light emitting devices (OLEDs) often require large surface areas for efficient light emission, which can be costly and inefficient, especially when used in applications where only peripheral regions are needed for illumination.
Innovation Solution
The implementation of OLEDs disposed only on peripheral regions of a substrate, with a mode expanding region to enhance light outcoupling, allowing for smaller OLED surface areas and efficient light distribution across a larger substrate area, including beveled edges and reflective surfaces to direct light internally.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the OLED area is reduced to peripheral regions only, then material cost is reduced, but the brightness uniformity across the substrate may be compromised
Solution Approach 1:
By moving from planar surface mounting to edge-mounted configuration, the patent creates a three-dimensional light distribution system. The light emitted from the edges naturally distributes across the substrate surface, providing uniform illumination without requiring excessive OLED material, thus maintaining brightness uniformity while reducing material quantity.
2Ease of manufacture
If OLEDs are disposed on the substrate surface, then fabrication is straightforward, but the light outcoupling efficiency is limited by total internal reflection
Solution Approach 1:
The patent exploits the edge geometry of the substrate to alter the optical path of emitted light. By positioning OLEDs on the peripheral edges, light can escape from the sides of the substrate where the critical angle for total internal reflection is different, thereby improving outcoupling efficiency without complicating the fabrication process.
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 reduces the OLED surface area required while maintaining or exceeding desired brightness levels, offering cost-effective and efficient light emission with aesthetic flexibility in lighting fixtures and displays.
Implementation Method 1
Another surface of the substrate may be roughened or include other features to outcouple light from the substrate
Implementation Method 2
The edges of the substrate may be beveled and/or reflective
Data Source
AI summary
Light emitting devices are provided that include one or more OLEDs disposed only on a peripheral region of the substrate. An OLED may be disposed only on a peripheral region of a substantially transparent substrate and configured to emit light into the substrate. Another surface of the substrate may be roughened or include other features to outcouple light from the substrate. The edges of the substrate may be beveled and/or reflective. The area of the OLED(s) may be relatively small compared to the substrate surface area through which light is emitted from the device. One or more OLEDs also or alternatively may be disposed on an edge of the substrate about perpendicular to the surface of the substrate through which light is emitted, such that they emit light into the substrate. A mode expanding region may be included between each such OLED and the substrate.