Semiconductor Light-Emitting Device With Reflective And Absorbing Layers
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Solution Overview
Problem
Conventional semiconductor light-emitting devices for vehicle headlights face challenges in achieving high light-emitting efficiency and contrast between the light-emitting and non-light-emitting surfaces while maintaining a small light-emitting surface, as existing structures often result in reduced light efficiency due to light absorption by light-shielding layers and require larger cavities for LED chips.
Innovation Solution
The semiconductor light-emitting device incorporates a base board with a wavelength converting layer, a transparent plate, a reflective material layer, and a light-absorbing layer, where the reflective material layer is formed with titanium oxide and the light-absorbing layer has a high absorption ratio, allowing for a small light-emitting surface with high contrast and efficiency by directing light towards the transparent plate and minimizing absorption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light-shielding layer is used to form a high contrast light-emitting line, then the contrast between light-emitting and non-light-emitting surfaces is improved, but the light-emitting efficiency is reduced due to light absorption
Solution Approach 1:
The patent removes the light-shielding layer from the conventional structure and replaces it with a reflective material layer that reflects light back toward the light-emitting surface, eliminating light absorption while maintaining the light-emitting line pattern. The light-shielding function is extracted and replaced by a reflective mechanism that preserves light energy.
Solution Approach 2:
The patent converts the harmful light absorption by the light-shielding layer into a beneficial reflection by the reflective material layer. Instead of absorbing light and reducing efficiency, the reflective layer bounces light back toward the emitting surface, turning potential energy loss into useful light output while still defining the light-emitting pattern.
2Area of stationary object
If the cavity size is reduced to maintain a small light-emitting surface, then the device size is reduced, but the space for LED chips and light-shielding structures is insufficient
Solution Approach 1:
The patent transitions from a two-dimensional planar light-shielding approach to a three-dimensional reflective structure that extends vertically. The reflective material layer is positioned at the bottom of the cavity and reflects light upward, allowing the light-emitting pattern to be defined by the vertical reflection geometry rather than requiring large horizontal spacing for light-shielding elements.
Solution Approach 2:
The reflective material layer serves multiple functions simultaneously: it defines the light-emitting pattern, reflects light to maintain efficiency, and structures the cavity space. This multi-functionality allows the device to achieve a compact size without sacrificing the necessary space for LED chips and optical structures.
3Device complexity
If a light-shielding layer is positioned close to the light-emitting surface to reduce device size, then the device complexity is reduced, but light absorption increases and efficiency decreases
Solution Approach 1:
Instead of using a light-shielding layer that absorbs light, the patent inverts the approach by using a reflective material layer that reflects light. The reflective layer is positioned at the bottom of the cavity close to the LED chips, reflecting light upward toward the light-emitting surface, thereby eliminating absorption losses while maintaining structural simplicity.
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 high light-emitting efficiency and contrast between the light-emitting and non-light-emitting surfaces, forming a horizontal cut-off line with high contrast for vehicle headlights using a simple structure, while maintaining a small light-emitting surface, thus overcoming the limitations of conventional devices.
Implementation Method 1
a wavelength converting layer including at least one phosphor, and encapsulating the semiconductor light-emitting chip
Implementation Method 2
a reflective material layer having an end of a top surface, and disposed between the frame and side surfaces of the wavelength converting layer and the transparent plate
Implementation Method 3
a light-absorbing layer having an end of a top surface, and disposed on the either one of the concave meniscus shape and the convex meniscus shape of the reflective material layer
Data Source
AI summary
A semiconductor light-emitting device and a method for manufacturing the same can include a wavelength converting layer encapsulating at least one semiconductor light-emitting chip to emit various colored lights including white light. The semiconductor light-emitting device can include a base board with the chip mounted thereon, a frame located on the base board, a transparent plate located on the wavelength converting layer, a reflective material layer disposed between the frame and both side surfaces of the wavelength converting layer and the transparent plate, and a light-absorbing layer located on the reflective material layer. The semiconductor light-emitting device can be configured to improve light-emitting efficiency and a contrast between a light-emitting and non-light-emitting surfaces by using the transparent material and light-absorbing layer. A wavelength-converted light that is emitted can have a high light-emitting efficiency and a high contrast between a light-emitting and non-light-emitting surface from a small light-emitting surface.