Ultra-slim Backlight Unit Optical Sheet Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct-type backlight units face challenges in achieving high luminance and color uniformity while maintaining a slim thickness, as they require optical lenses and diffusion plates that limit thickness and flexibility due to the need for sufficient optical distance.
Innovation Solution
A backlight unit design featuring a substrate with light-emitting devices and an optical sheet that refracts or disperses light through a patterned structure, eliminating the need for optical lenses and diffusion plates, allowing for a reduced optical distance and thinner profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If optical lenses and diffusion plates are included to achieve high luminance and color uniformity, then optical uniformity is improved, but thickness increases and flexibility is limited
Solution Approach 1:
The patent combines the functions of light diffusion and optical pattern formation into a single optical sheet. The optical sheet contains both diffusion particles for scattering light and an optical pattern (such as microlenses or prisms) for directing light, eliminating the need for separate diffusion plates and optical lenses, thereby reducing thickness while maintaining luminance uniformity.
Solution Approach 2:
The optical sheet serves multiple functions simultaneously: it diffuses light to improve uniformity, refracts light through its optical pattern to control distribution, and maintains a thin profile. This multi-functional design replaces multiple separate components (diffusion plate + optical lens) with a single integrated element, resolving the contradiction between achieving optical uniformity and reducing thickness.
2Ease of manufacture
If sufficient optical distance is secured between light source and diffusion plate, then light diffusion effectiveness is improved, but device thickness increases
Solution Approach 1:
The patent uses a thin film optical sheet that can be placed in direct contact with or very close to the light-emitting devices. The optical pattern within this thin film structure provides sufficient light diffusion and redirection effects without requiring a large optical distance, enabling effective light diffusion in a compact space.
Solution Approach 2:
The patent changes the optical parameters by incorporating an optical pattern (such as microlens arrays or prism patterns) into the optical sheet. This pattern modifies the light path and diffusion characteristics, allowing effective light diffusion to occur over a shorter distance compared to conventional diffusion plates that rely solely on material thickness and particle scattering.
3Illumination intensity
If multiple optical sheets and components are included, then optical performance is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple optical functions (diffusion, refraction, light distribution control) into a single optical sheet with an integrated optical pattern. This consolidation reduces the number of separate optical components from multiple sheets and lenses to one unified element, simplifying the overall device structure while maintaining or improving optical performance.
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 enables high luminance and color uniformity without the need for optical lenses and diffusion plates, resulting in an ultra-slim backlight unit that supports flexible displays and reduces manufacturing costs.
Implementation Method 1
emits light of the light-emitting device incident on one surface thereof to the other surface facing the one surface, while refracting or dispersing the light in a direction different from a direction in which the light is incident due to an optical pattern formed therein
Implementation Method 2
The optical sheet may have the optical pattern formed between the one surface and the other surface thereof so that an exit angle of the light emitted through the other side is greater than an incident angle of the light incident on the one surface
Data Source
AI summary
Provided is a backlight unit including: a substrate; a plurality of light-emitting devices mounted on the substrate; and an optical sheet disposed above the light-emitting devices, wherein the optical sheet is in contact with a light-emitting surface of at least one light-emitting device via one surface thereof, and emits light of the light-emitting device incident on one surface thereof to the other surface facing the one surface, while refracting or dispersing the light in a direction different from a direction in which the light is incident due to an optical pattern formed therein.