Light Diffusing Lens with Sheet Escape Recess for Backlight Alignment
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Solution Overview
Problem
The existing light diffusing lenses in direct lighting type backlight units face issues with warpage of the reflection sheet due to thermal expansion and misalignment, leading to non-uniform light distribution and degradation of light characteristics, which is exacerbated by the increasing demand for high-definition displays like 8K resolution.
Innovation Solution
A light diffusing lens design featuring a concave light entering portion, a convexly curved light emitting portion, a reflection portion with an inclined surface, and a flange with a sheet escape recess and pressing protrusions to prevent warpage and ensure precise alignment, along with first and second light patterns to manage light direction and emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the gap between LEDs is reduced to solve luminance uniformity, then luminance uniformity is improved, but manufacturing cost increases due to requiring more LEDs
Solution Approach 1:
A light diffusing lens is introduced as an intermediary component between the LED and the liquid crystal panel. The lens receives light from the LED and diffuses it to achieve uniform luminance distribution, eliminating the need to reduce LED spacing and thereby avoiding increased manufacturing costs
Solution Approach 2:
The patent changes the optical parameters of the light distribution system by introducing a lens with specific refractive index and curvature. This transforms the light distribution pattern from point-source concentrated lighting to uniformly diffused lighting, achieving luminance uniformity without increasing LED quantity
2Illumination intensity
If a light diffusing lens is placed in each LED to disperse light, then luminance uniformity is improved, but device complexity increases due to additional components and precise alignment requirements
Solution Approach 1:
The light diffusing lens is integrated with the LED module as a single assembly unit. The lens is positioned to receive light directly from the LED without requiring separate alignment procedures, merging the light source and diffusing function into one cohesive component that simplifies assembly
Solution Approach 2:
The lens structure includes self-aligning features such as a recessed mounting area that automatically positions the lens correctly relative to the LED when assembled. This self-service mechanism eliminates the need for complex alignment tools or procedures, reducing assembly complexity while maintaining optical precision
3Loss of energy
If the reflection sheet is placed close to the light diffusing lens to improve light utilization, then light utilization efficiency is improved, but warpage occurs due to thermal expansion and misalignment
Solution Approach 1:
A gap structure is pre-designed between the reflection sheet and the light diffusing lens mounting position. This gap acts as a cushioning space that accommodates thermal expansion of the reflection sheet and prevents direct contact that would cause warpage, while still maintaining sufficient proximity for effective light reflection and utilization
4Reliability
If the flange is positioned to prevent damage to the light emitting portion, then reliability is improved, but light loss increases due to shifting and misalignment
Solution Approach 1:
The flange structure is designed with differentiated local functions: one region provides mechanical protection for the light emitting portion, while another region maintains precise optical alignment. The protective flange edge is positioned to shield the LED without obstructing the light path, achieving both reliability improvement and minimal light loss
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 solution effectively prevents warpage and maintains high-quality light characteristics by ensuring accurate alignment and uniform luminance, reducing light loss and luminance differences, thus supporting high-definition displays with improved backlighting.
Implementation Method 1
a light diffusing lens (300) coupled to the substrate (100) while covering the LED (200}, wherein the light diffusing lens (300) allows light of the LED (200) to pass through the light diffusing lens
Implementation Method 2
a reflection portion (340) formed on the lower surface of the main body (310) along a circumference of the light entering portion (320)
Data Source
AI summary
The present disclosure relates to a light diffusing lens for a light emitting device, and the light diffusing lens according to an embodiment of the present disclosure includes: a light entering portion concavely formed on a center of a lower surface of a main body; a light emitting portion formed on an upper surface of the main body in a curved shape; a reflection portion formed on the lower surface of the main body along a circumference of the light entering portion; and a flange protruding outward from a lower end of the light emitting portion along an outer circumference of the main body, wherein the flange has a sheet escape recess formed on a lower portion thereof along a circumferential direction to allow an end of a sheet hole of a reflection sheet to escape thereinto, and is formed to be spaced apart from the reflection portion.