Optical Sheet Hole Layout for Uniform Surface Light Luminance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Concentric luminance unevenness occurs in surface light source devices due to increasing hole diameters of through holes away from the light source, leading to non-uniform luminance.

Innovation Solution

The optical sheet is designed with through holes of varying diameters arranged in a matrix pattern, where the diameters increase as one moves away from the light source, and specific sections have hole diameters set to differ from adjacent holes, allowing for adjusted luminance and reduced unevenness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the hole diameters of the through holes are gradually increased as moving away from the light source to make the luminance uniform, then the luminance uniformity is improved, but concentric luminance unevenness occurs centered on the light source

Engineering Contradiction:
Improveluminance uniformityVSAvoidconcentric luminance unevenness
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by making different parts of the optical sheet have different hole diameter patterns. Specifically, the optical sheet is divided into a first region (closer to light source) and a second region (farther from light source), with each region having through holes of different diameters. This local differentiation allows each region to compensate for its specific luminance characteristics, achieving overall uniformity while avoiding concentric patterns that cause luminance unevenness.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The optical sheet is segmented into multiple regions with different through hole configurations. The first region has through holes with a first diameter, while the second region has through holes with a second diameter different from the first. This segmentation strategy breaks the continuous gradient approach into discrete zones, preventing the formation of concentric luminance patterns while still achieving the goal of uniform luminance distribution across the entire optical sheet.

Inventive Principle:
Principle #1Segmentation

2Use of energy by moving object

If the hole diameters are set according to distance from light source, then light transmission is optimized, but luminance unevenness occurs in regions with same hole diameter

Engineering Contradiction:
Improvelight transmission efficiencyVSAvoidluminance unevenness
Core Design Contradiction:
Use of energy by moving objectVSIllumination intensity

Solution Approach 1:

The patent implements local quality by assigning different hole diameters to different regions based on their distance from the light source. The first region (nearer to light source) uses through holes with a first diameter, while the second region (farther from light source) uses through holes with a second diameter. This localized optimization ensures that each region's hole diameter is tailored to its specific lighting conditions, maximizing light transmission efficiency while preventing luminance unevenness that would occur with uniform hole diameters across the entire sheet.

Inventive Principle:
Principle #3Local quality

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 achieves uniform luminance and suppresses concentric luminance unevenness by adjusting the amount of light transmitted through the optical sheet, ensuring consistent illumination across the display device.

Implementation Method 1

an optical sheet arranged to face the light sources, the optical sheet including a transmission part having a plurality of through holes that are configured to transmit light emitted from the light sources

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a reflection part configured to reflect the light emitted from the light sources

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 3

a diffusion plate configured to diffuse the light transmitted through the transmission part

Methodology Applied
Scientific EffectLight diffusion: Scattering

Data Source

PatentEP3910413B1Surface light source device, display device and optical sheet manufacturing method
Publication Date: 2024.10.16 FUNAI ELECTRIC CO LTD
  • EP3910413B1 patent drawingFigure 1~2
  • EP3910413B1 patent drawingFigure 3
  • EP3910413B1 patent drawingFigure 4

AI summary

A surface light source device comprises: a plurality of light sources (1), an optical sheet (2), and a diffusion plate (3). The optical sheet includes a transmission part (21) having a plurality of through holes that are configured to transmit light emitted from the light sources, and a reflection part (22) configured to reflect the light emitted from the light sources. The optical sheet is configured such that the through holes include a plurality of first through holes each having a hole diameter set according to a distance from a respective one of the light sources, and at least one second through hole each having a hole diameter set to a different size from the hole diameter set according to the distance from the respective one of the light sources.