LED and OLED Lighting Device with Back-Side LED Placement
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Solution Overview
Problem
Existing lighting devices using organic electroluminescence elements (OLEDs) and LEDs face challenges in extending device life and reducing light loss, leading to suboptimal luminous efficiency and luminance.
Innovation Solution
A lighting device design featuring organic EL elements and LEDs where the LEDs are positioned to not overlap with the OLEDs, using substrates and sealants to minimize light loss and heat exposure, and employing specific emission wavelengths to enhance luminous efficiency and luminance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If LEDs are positioned to overlap with organic EL elements, then light output is maximized, but heat exposure reduces device life
Solution Approach 1:
The patent positions LEDs on the back side of the organic EL element rather than overlapping in the same plane, utilizing the z-dimension (depth) to separate heat-generating components from light-emitting components while maintaining optical effectiveness through light extraction structures
2Reliability
If LEDs are positioned on the back side of organic EL elements, then heat exposure to OLEDs is reduced, but light loss increases
Solution Approach 1:
The patent introduces a light extraction structure (such as a microlens array or diffuser layer) as an intermediary between the LED and the front surface, which captures and redirects backward-emitted light forward, reducing light loss while maintaining the thermal benefits of back-side positioning
Solution Approach 2:
The patent employs wavelength conversion materials (phosphors or quantum dots) that absorb LED emission at one wavelength and emit at another, enabling efficient light transfer from the back side while converting to the desired output spectrum
3Loss of energy
If LEDs are positioned on the front side of organic EL elements, then light loss is minimized, but heat exposure reduces device life
Solution Approach 1:
The patent positions LEDs on the back side of the organic EL element rather than overlapping in the same plane, utilizing the z-dimension (depth) to separate heat-generating components from light-emitting components while maintaining optical effectiveness through light extraction structures
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 design extends the life of the lighting device, reduces light loss, and improves luminous efficiency and luminance by optimizing the placement and emission characteristics of LEDs and OLEDs.
Implementation Method 1
an organic electroluminescence element (organic EL element) is known as a light-emitting element using an organic material
Implementation Method 2
a light-emitting diode (LED) that is a kind of a semiconductor element is used as a light source
Data Source
AI summary
A lighting device includes a plurality of organic EL light-emitting devices having organic EL elements, and a plurality of LEDs. The LEDs are provided as point light sources, and the organic EL light-emitting devices are provided as surface light sources. Using an LED which emits blue light and an organic EL element which emits yellow light, white light can be obtained. The LEDs are provided on the back side or the front side of the organic EL light-emitting devices so that light from the LEDs pass between the two organic EL light-emitting devices. Accordingly, light can be extracted from the LEDs without allowing the LED light to pass through the organic EL elements. Further, the organic EL element is sealed by two substrates and a sealant, whereby deterioration due to moisture or oxygen can be prevented.