Organic EL Device with Ellipsoidal Reflector for Color Tuning
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Solution Overview
Problem
The existing organic EL panels with RGB separation structures face limitations in aperture ratio, making it difficult to increase luminous flux while maintaining panel life, as increasing driving current shortens the panel's lifespan.
Innovation Solution
An organic EL device configuration that includes an organic EL panel, an ellipsoidal reflector, and a phosphor, where the phosphor is positioned at the first focal point of the reflector and light enters the substrate at the second focal point, allowing for color tunability by using a laser to excite the phosphor and diffuse light in the substrate, thereby mixing colors and increasing luminous flux without restricting the aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If RGB light emission layers are formed separately to achieve color adjustment, then color tunability is improved, but the aperture ratio is restricted and the amount of luminous flux is reduced
Solution Approach 1:
The invention separates the color generation function from the light emission function. Instead of having separate RGB light emission layers, a single white light emission layer is used combined with a phosphor layer that can be selectively excited by a laser beam at specific wavelengths to generate different colors. This segmentation allows the organic EL panel to maintain high aperture ratio while achieving color tunability.
Solution Approach 2:
The phosphor layer acts as an intermediary between the white light emission layer and the final color output. The phosphor converts specific wavelengths from the white light into different colors, enabling color adjustment without requiring separate RGB emission layers. The laser beam serves as another intermediary to selectively excite the phosphor at different wavelengths for color tuning.
2Productivity
If driving current is increased to increase the amount of luminous flux, then luminous flux is improved, but the life of the organic EL panel is shortened
Solution Approach 1:
The invention changes the operational parameters of the organic EL panel by using a white light emission layer instead of separate RGB layers, and by introducing laser beam excitation of the phosphor layer. This allows the panel to operate at lower driving currents while maintaining or increasing luminous flux output, thereby extending panel life.
3Device complexity
If emission color is determined by organic EL layer material to simplify structure, then device complexity is reduced, but color tunability is lost
Solution Approach 1:
The invention introduces dynamic color control capability to the organic EL panel by enabling selective laser beam excitation of the phosphor layer at different wavelengths. This allows the emission color to be dynamically adjusted without changing the physical structure or material composition of the organic EL layer, maintaining structural simplicity while achieving color tunability.
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 enables user-adjustable color emission and increased luminous flux from the organic EL panel, allowing for a wider range of applications such as lighting and display devices without compromising panel lifespan.
Implementation Method 1
a phosphor 32, in an ellipsoidal reflector 31, outside the organic EL panel 16, wherein the phosphor 32 is disposed at a first focal point of the ellipsoidal reflector 31
Implementation Method 2
an ellipsoidal reflector 31, outside the organic EL panel 16, wherein the phosphor 32 is disposed at a first focal point of the ellipsoidal reflector 31 and the light incident portion 15 of the substrate 11 is positioned at a second focal point of the ellipsoidal reflector 31
Data Source
AI summary
An organic EL device includes an organic EL panel, an ellipsoidal reflector, a phosphor, and a laser. The organic EL panel includes a substrate and at least one organic EL element, and the substrate includes at least one light incident portion on which light is incident from the outside. The ellipsoidal reflector is disposed outside the organic EL panel in such a manner that the phosphor is disposed at a first focal point of the reflector and the light incident portion of the substrate is positioned at a second focal point of the reflector. The laser is disposed outside the organic EL panel in such a manner that the phosphor can be irradiated with a laser beam. Light emitted from the phosphor enters the substrate from the light incident portion. The light emitted from the phosphor that has entered the substrate diffuses in the in-plane direction of the substrate.