Light Concentrating Sheet for LCD Backlight
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Solution Overview
Problem
The existing backlight units for liquid crystal displays face issues with deformation and light loss due to friction and contact problems between the prism film and the light guide plate, leading to reduced brightness uniformity and efficiency.
Innovation Solution
A light concentrating sheet is designed with a first and second base film, each having flat surfaces, and corresponding light concentrating films with different thermal expansion coefficients, which are laminated together to prevent deformation and enhance light concentration, using materials like polyethylene terephthalate and UV-curable resins to form a pattern with convex and concave portions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the prism film has convex and concave portions to concentrate light, then light concentration is improved, but deformation and friction occur at contacting portions leading to light loss
Solution Approach 1:
A cushioning layer is introduced as an intermediary between the prism film and the light guide plate. This cushioning layer prevents direct contact between the convex portions of the prism film and the light guide plate, eliminating friction and deformation while maintaining the light concentration function of the prism film structure.
Solution Approach 2:
The cushioning layer is pre-positioned between the prism film and light guide plate to prevent deformation before it occurs. By providing this protective layer in advance, the system prevents mechanical stress and friction that would otherwise cause light loss and brightness non-uniformity.
2Productivity
If the prism film contacts the light guide plate directly to improve light guiding, then light guiding efficiency is improved, but friction causes particles and brightness uniformity degradation
Solution Approach 1:
The cushioning layer serves as a mediator that allows the prism film to maintain its light-guiding function while preventing direct mechanical contact with the light guide plate. This eliminates particle generation from friction while preserving optical performance.
3Stability of the object's composition
If the base film is disposed between the prism film and light guide plate to prevent contact, then deformation is reduced, but light concentration efficiency decreases
Solution Approach 1:
The cushioning layer is designed as a thin, flexible film that optically does not interfere with light concentration while mechanically preventing deformation. This thin film structure allows light to pass through effectively while still providing the necessary mechanical protection and contact prevention.
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 deformation and light loss, maintaining brightness uniformity and efficiency by ensuring flat surfaces for optimal light path alignment and reducing mechanical stress, thus improving the overall performance of the liquid crystal display module.
Implementation Method 1
The light from the light source 16 at a side of the light guide plate 20 is guided into the light concentrating sheet 10 by the light guide plate 20
Implementation Method 2
The prism film 15 has a convex portion 12 and a concave portion 14... light emitted from the light source 16... is changed into a plane light source
Data Source
AI summary
A light concentrating sheet for a liquid crystal display module includes a first base film having flat inner and outer surfaces; a first light concentrating film on the first base film and having a first thermal expansion coefficient; a second light concentrating film on the first light concentrating film and having a second thermal expansion coefficient; and a second base film on the second light concentrating film and having flat inner and outer surfaces.