Curved Phosphor Layer Geometry for Uniform Surface Lighting

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Solution Overview

Problem

Conventional surface light source lighting devices experience dark lines at the interface between the upper and side surfaces due to the distance between the light emitting device and the substrate, leading to non-uniform luminance.

Innovation Solution

A lighting device with a substrate, light sources on the upper surface, a resin layer, and a phosphor layer featuring a curved surface design that overlaps with the light sources, where the phosphor layer includes a first region parallel to the substrate and a second region extending from the side surface toward the substrate, with specific distance and curvature configurations to minimize dark lines and enhance luminance uniformity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If LEDs are positioned close to the plant growth medium, then illumination intensity is improved, but risk of overheating and burning the plants worsens

Engineering Contradiction:
Improveillumination intensityVSAvoidoverheating and burning
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The lighting device divides the illumination function into multiple separate LED modules arranged in a grid pattern, allowing each module to be positioned at optimal distances from the plant medium. This segmentation enables close positioning for high illumination while distributing heat across multiple spaced-apart sources, preventing concentrated overheating.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a reflective hood structure as an intermediary between the LED modules and the plant growth medium. This hood reflects and distributes light downward while blocking direct exposure to concentrated heat sources, mediating between the need for high illumination and the need to prevent overheating.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If LEDs are positioned far from the plant growth medium, then risk of overheating is reduced, but illumination intensity decreases

Engineering Contradiction:
Improveoverheating riskVSAvoidillumination intensity
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent transitions from a single-point light source approach to a two-dimensional array of LED modules arranged in a grid. This dimensional change allows light to be delivered from multiple directions simultaneously, maintaining high illumination intensity even when individual LEDs are positioned at safer distances from the plant medium.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The lighting device integrates multiple functions into a single system: the LED modules provide both illumination and controlled heating, while the reflective hood provides both light distribution and thermal management. This multi-functionality allows the system to achieve high illumination without requiring LEDs to be positioned extremely close to the plants, as the hood manages the thermal effects.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of operation

If a reflective hood is added to direct light downward, then light distribution is improved, but device complexity increases

Engineering Contradiction:
Improvelight distributionVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the reflective hood structure with the LED module assembly, integrating the light-distribution function directly into the lighting unit itself. This merging eliminates the need for separate external hoods or complex mounting structures, as the hood is incorporated as a single integrated component that directs light downward while maintaining ease of installation and operation.

Inventive Principle:
Principle #5Merging (Combining)

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 curved phosphor layer design effectively prevents dark lines and improves luminance uniformity by adjusting the distances between the light sources and the phosphor layer, resulting in a more uniform and efficient light emission.

Implementation Method 1

a plurality of light emitting diodes (LEDs) arranged in a grid-like pattern

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

The housing may have a reflective hood which reflects light from the LEDs and directs it downwards towards the plant growth medium

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3839323B1Lighting device
Publication Date: 2023.09.06 LG INNOTEK CO LTD
  • EP3839323B1 patent drawingFigure 1~2
  • EP3839323B1 patent drawingFigure 3~4
  • EP3839323B1 patent drawingFigure 5~6

AI summary

The lighting device disclosed in the embodiment includes a substrate, light sources disposed on the substrate at predetermined intervals, a resin layer disposed on the substrate and the light sources, and a phosphor layer disposed on the resin layer. The phosphor layer includes a first region overlapped with some of the N light sources in a direction perpendicular to the substrate and including a flat region, and a second region extending from a side surface of the first region toward the substrate and including a curved surface. The second region includes a first point horizontally in contact with the substrate from a center of a first light source closest to the side surface of the resin layer, a second point on the curved surface, and a third point where a straight line perpendicular to the substrate passes the center of the first light source, and a second distance from the center of the first light source to the second point is greater than a first distance from the center of the first light source to the first point, and is smaller than a third distance from the center of the first light source to the third point.