Backlight Unit External Tape Light Guide Plate
Solution Overview
Problem
Backlight units in liquid crystal display devices face issues with light efficiency and manufacturing costs due to resin processes, which lead to light leakage and increased bezel areas, affecting luminance and power consumption.
Innovation Solution
The use of an external tape covering the lateral parts of the light guide plate in the backlight unit, including a reflective layer and a color coat layer, enhances light efficiency, reduces manufacturing costs, and improves bonding strength between components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If resin processes are used to increase bonding strength between the light guide plate and surrounding components, then bonding strength is improved, but light efficiency decreases due to light leakage through resins
Solution Approach 1:
A light blocking member (black paint or black tape) is introduced as an intermediary layer between the resin and the light guide plate. This intermediary blocks light that would otherwise leak through the resin, while the resin continues to provide bonding strength. The light blocking member mediates between the conflicting requirements of bonding strength and light efficiency.
Solution Approach 2:
The solution segments the bonding function and light blocking function into separate components: the resin provides bonding strength while the light blocking member (applied in specific patterns such as stripes or at corners) provides light blocking. This segmentation allows each component to optimize its specific function without compromising the other.
2Strength
If resin processes are used to bond components, then bonding strength is improved, but manufacturing costs increase due to multiple process steps
Solution Approach 1:
The light blocking member application is merged with the existing resin bonding process. The light blocking member is applied to the light guide plate before resin bonding, combining two functions (light blocking and bonding preparation) into a single process sequence, thereby reducing the number of separate process steps.
Solution Approach 2:
The light blocking member serves dual purposes: it blocks light leakage and also acts as a base layer that improves resin adhesion to the light guide plate. This self-service approach eliminates the need for separate adhesion promotion treatments, reducing process complexity.
3Strength
If resin processes are used for bonding, then bonding strength is improved, but bezel area increases to shield resin application areas
Solution Approach 1:
The light blocking member is applied locally only where light leakage occurs (at the interfaces between the light guide plate and surrounding components) rather than covering the entire light guide plate. This localized application minimizes the impact on display area while effectively preventing light leakage, thereby reducing the need for increased bezel area.
4Loss of energy
If light blocking measures are implemented to prevent light leakage, then light efficiency is improved, but manufacturing complexity increases due to additional process steps
Solution Approach 1:
The light blocking member can be implemented as a thin film or tape that is easily applied to the light guide plate surface. This thin film approach is simpler than rigid structures and can be applied in a single step during the assembly process, minimizing manufacturing complexity while effectively blocking light leakage.
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 external tape increases luminance and power efficiency while minimizing the bezel area, thereby enhancing the overall performance and reducing costs in the liquid crystal display device.
Implementation Method 1
The external tape may include a reflective layer and a color coat layer positioned on the reflective layer
Data Source
AI summary
The present disclosure relates to a backlight unit and a liquid crystal display device having a backlight unit. The backlight unit includes a light guide plate, a light source assembly positioned adjacent to a light-incident surface among lateral surfaces of the light guide plate, and an external tape covering the entire lateral surface of the light guide plate except the light-incident surface and parts of an upper surface and a lower surface of the light guide plate. Thus, the light efficiency of the backlight unit may be increased and the manufacturing costs reduced. Further, since the light efficiency of the backlight unit is increased, the luminance and power consumption of the liquid crystal display device can be improved.