Optical Sheet Communicating Grooves for LCD Warpage Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In liquid crystal display devices, the light-blocking adhesive tape and double-sided tape create a gap between the optical sheet and the liquid crystal panel, leading to air pockets that cause the optical sheet to warp and stick to the panel, resulting in uneven luminance and Newton ring patterns, which become more pronounced with thinner optical sheets and reduced device thickness.
Innovation Solution
Incorporating communicating grooves on the optical sheet that connect from the outer peripheral end face to the surface opposing the liquid crystal panel, allowing air in the gap to escape and preventing warpage by eliminating air pockets between the optical sheet and the liquid crystal panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the gap between the optical sheet and the liquid crystal panel is reduced to achieve thinner device profile, then the device thickness is reduced, but air pockets are trapped more easily causing optical sheet warpage and Newton ring patterns
Solution Approach 1:
The optical sheet is segmented by forming communicating grooves that divide the enclosed space into multiple regions. This segmentation allows air pockets to be channeled out through the grooves rather than being trapped in a single enclosed space, preventing warpage while maintaining the thin gap structure
Solution Approach 2:
The communicating grooves act as intermediary channels that facilitate air escape from the gap between the optical sheet and liquid crystal panel. These grooves provide a controlled pathway for air to exit during the bonding process, preventing the formation of harmful air pockets
2Length of stationary object
If the optical sheet is made thinner to achieve reduced device thickness, then the overall device becomes thinner, but the optical sheet becomes more susceptible to warpage from air pockets
Solution Approach 1:
The communicating grooves segment the optical sheet structure, creating multiple small enclosed spaces rather than one large enclosed space. This segmentation reduces the volume of air pockets that can form and provides multiple escape routes, maintaining flatness even in thinner optical sheets
Solution Approach 2:
The communicating grooves are strategically positioned at specific locations on the optical sheet where air pockets are most likely to form. This local modification provides targeted air escape pathways without compromising the overall optical performance of the sheet
3Strength
If adhesive tapes are used to bond the optical sheet and liquid crystal panel, then bonding is achieved, but air pockets are trapped in the enclosed space causing warpage
Solution Approach 1:
The communicating grooves are pre-formed on the optical sheet before the bonding process. This preliminary action ensures that air escape pathways are already in place during adhesive application, allowing air to be continuously vented as the bonding progresses, preventing warpage while maintaining bonding strength
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 communicating grooves effectively reduce warpage of the optical sheet, preventing uneven luminance and Newton ring patterns, and facilitate easier ventilation and bonding, enhancing the reliability and performance of liquid crystal display devices.
Implementation Method 1
the at least one communicating groove of the optical sheet serves as a passageway for air that is present in a gap between the liquid crystal panel and the optical sheet. The air is released to the outside from a side of the lighting device through the at least one communicating groove.
Data Source
AI summary
A lighting device for illuminating an illuminated body with light includes a light source, a light guide plate, and an optical sheet. The light guide plate is configured to guide light from the light source. The optical sheet is configured to impart an optical effect to light exiting from the light guide plate. The optical sheet includes at least one communicating groove that communicates from an outer peripheral end face of the optical sheet to a surface opposed to the illuminated body.