Planar Lighting Device Non-Adhesive Strip Brightness
Solution Overview
Problem
Conventional planar lighting devices experience reduced brightness due to adhesive tapes with refractive indices close to that of the light guide plate, causing light to exit from the main surfaces, which affects the overall brightness and efficiency of the lighting system.
Innovation Solution
A planar lighting device design incorporating a strip-shaped member with non-adhesive portions that do not adhere to the light guide plate, specifically positioned to prevent light emission from the main surfaces, thereby maintaining brightness and allowing for a narrower frame configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an adhesive tape with refractive index close to that of the light guide plate is used, then the adhesive tape can be effectively adhered to the light guide plate, but light exits from the main surface to the adhesive layer resulting in lower brightness
Solution Approach 1:
The adhesive tape is divided into multiple regions: a first region that adheres to the light guide plate and a second region that does not adhere, creating distinct functional zones that simultaneously achieve adhesion and light trapping
Solution Approach 2:
Different regions of the adhesive tape have different adhesive properties - the first region has adhesive capability for structural support while the second region is non-adhesive to prevent light leakage, optimizing local functions for different purposes
2Strength
If adhesive tape is adhered to the light guide plate, then structural support and positioning are provided, but light exits from the main surface reducing overall brightness
Solution Approach 1:
The adhesive tape is segmented into adhesive and non-adhesive regions, allowing the adhesive portion to provide structural support while the non-adhesive portion prevents light leakage
Solution Approach 2:
The adhesive tape exhibits spatially varying adhesive properties, with the first region providing structural adhesion and the second region providing optical functionality by preventing light exit
3Reliability
If the adhesive layer has refractive index close to the light guide plate, then adhesion is improved, but light refraction is reduced causing light to exit to the adhesive layer
Solution Approach 1:
The adhesive tape is divided into regions with different adhesive properties, allowing the non-adhesive region to trap light and prevent energy loss while the adhesive region maintains structural integrity
Solution Approach 2:
Different regions of the adhesive tape have different optical and adhesive properties, with the non-adhesive region optimizing light trapping to prevent energy loss while the adhesive region ensures proper bonding
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 light emission from the main surfaces, enhancing the mean and center brightness of the planar lighting device while enabling a narrower frame width, addressing the issue of reduced brightness and uneven light distribution.
Implementation Method 1
If an adhesive layer of the adhesive tape has a refractive index close to that of the light guide plate, part of light from the LEDs exits from one of the main surfaces of the light guide plate to the adhesive layer
Data Source
AI summary
A planar lighting device according to an embodiment includes a light guide plate, a plurality of light sources, and a strip-shaped member. The light guide plate has a side surface and two main surfaces. One of the two main surfaces emits light entered from the side surface. The light sources face the side surface and are arranged in a longitudinal direction of the side surface and emit light that enters the side surface. The strip-shaped member extends in the longitudinal direction of the side surface and is adhered to a region on at least one of the two main surfaces closer to the light sources. The strip-shaped member includes non-adhesive portions disposed at positions facing regions of the at least one of the two main surfaces in front of the light sources. The non-adhesive portions do not adhere to the light guide plate.