Concave Light-Outgoing Surface Resolves Backlight Coupling Efficiency
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Solution Overview
Problem
Existing light emitting apparatuses have a wide radiation angle in the short-axis direction, which limits their coupling efficiency with light guiding plates, resulting in reduced luminance in plane light-sources.
Innovation Solution
A light emitting apparatus with a concave light-outgoing surface formed by a transparent sealing resin, where the depth of the concave surface is equal to or deeper than half the width of the light-outgoing surface in the short-axis direction, and a wire bonded to the light emitter curved to coincide with the deepest section of the concave surface, enhancing light reflection and reducing radiation angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a flat light-outgoing surface is used in conventional light emitting apparatus, then the structure is simple and easy to manufacture, but the radiation angle in the short-axis direction is wide, resulting in poor coupling efficiency with light guiding plates
Solution Approach 1:
The patent applies curvature by forming a concave spherical surface on the light-outgoing surface of the sealing resin. This curved surface design focuses the emitted light in the short-axis direction, reducing the radiation angle and improving coupling efficiency with the light guiding plate, while resolving the contradiction between structural simplicity and optical performance.
2Reliability
If the sealing resin is filled to the top surface of the recess section and thermally cured, then the chip and wire are protected, but a smooth parabolic concave surface is formed with the deepest portion at the central section, which increases the radiation angle
Solution Approach 1:
The patent applies local quality by creating a specific concave surface geometry where the deepest portion is positioned at the periphery rather than the center. This localized variation in surface depth controls the light reflection and emission characteristics, directing more light axially while maintaining the protective sealing function.
Solution Approach 2:
The patent changes the dimensional distribution of the concave surface by shifting the deepest portion from the central position to the peripheral position. This dimensional reconfiguration alters the light path and radiation pattern, concentrating light emission in the axial direction while preserving the protective enclosure.
3Illumination intensity
If diffusion agents are added to the sealing resin to reflect and scatter light, then light that is emitted from the chip is enhanced, but the radiation angle in the short-axis direction increases, reducing coupling efficiency
Solution Approach 1:
The patent changes the geometric parameters of the light-outgoing surface by forming a concave spherical shape with a specific depth-to-diameter ratio. This parameter modification controls the light emission pattern, reducing the radiation angle in the short-axis direction and improving coupling efficiency, while maintaining sufficient light intensity through the curved surface geometry rather than diffusion agents.
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 design reduces the radiation angle and increases luminous intensity in the axial direction, improving coupling efficiency with light guiding plates, such as those used in liquid crystal display apparatuses, and allows for a more compact and high-luminance backlight apparatus.
Implementation Method 1
When excited by light emitted from the chip 202, the fluorescent material 206 emits a light beam having a different waveform.
Implementation Method 2
a transparent sealing resin that seals the light emitter, and forms a concave surface that is a light-outgoing surface via which light outgoes
Data Source
AI summary
A light emitting apparatus according to the present invention includes: a placement surface that includes an electrode; a light emitter that is placed on the placement surface; and a transparent sealing resin that seals the light emitter, and forms a concave surface that is a light-outgoing surface via which light outgoes. The concave surface faces a surface of the light emitter, from which surface light is emitted. The light emitter and the electrode are connected via a wire that is curved in such a way that a top section of the curved wire substantially coincides with a deepest section of the concave surface.