Backlight Module Reflective Cover Polar Coordinate Design
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Solution Overview
Problem
Conventional backlight modules for LCDs suffer from non-uniform brightness due to limited illuminating spaces of point light sources, resulting in dark regions where light does not reach, leading to inconsistent illumination.
Innovation Solution
A backlight module design incorporating a light guide plate and a reflective cover with specially defined reflective surfaces in polar coordinates, along with scattering structures and microstructures, to redirect and distribute light uniformly across the LCD panel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If point light sources are used in the backlight module, then the device structure is simple and easy to manufacture, but the illuminating space is limited resulting in non-uniform brightness and dark regions
Solution Approach 1:
The reflective cover is divided into multiple reflective units, each with specifically designed reflective surfaces that segment the light redistribution task. This segmentation allows each unit to handle specific angular ranges of light reflection, collectively achieving uniform illumination across the entire light-emitting surface while maintaining manufacturing simplicity.
Solution Approach 2:
The reflective surfaces are designed with specific geometric parameters defined by polar coordinate equations, where the curvature and orientation of reflective surfaces are precisely controlled. By changing the geometric parameters of the reflective surfaces according to mathematical formulas, the patent achieves uniform light distribution while keeping the overall structure simple and manufacturable.
2Device complexity
If conventional reflective sheets are used, then the structure is simple, but light redistribution is insufficient leading to dark regions at the edges
Solution Approach 1:
The reflective cover transitions from a conventional two-dimensional flat reflective sheet to a three-dimensional structure with curved reflective surfaces. By introducing dimensional complexity through curved surfaces defined by polar coordinate equations, the patent achieves superior light redistribution and eliminates dark regions while maintaining reasonable structural complexity.
Solution Approach 2:
The reflective surfaces are designed with curved geometries rather than flat surfaces. The curved reflective surfaces, defined by specific polar coordinate equations, enable better light redirection to edge areas of the light-emitting surface, expanding the effective illumination coverage area while managing structural complexity.
3Illumination intensity
If multiple light sources are added to expand illuminating space, then brightness uniformity improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The reflective cover acts as an intermediary optical element between the point light sources and the light-emitting surface. Instead of adding more light sources, the patent uses the reflective cover with specifically designed reflective surfaces to redistribute light from existing sources, achieving uniform illumination while avoiding increased device complexity.
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 ensures a uniform planar illuminating light distribution, enhancing brightness and coverage across the LCD panel by effectively redirecting light from the light sources through the reflective cover and microstructures, eliminating dark regions.
Implementation Method 1
The reflective cover includes a reflective unit having two reflective surfaces defining a space with a bottom. The light source is accommodated in the bottom of the space.
Data Source
AI summary
A backlight module (30) includes a light source (42) for emitting light, a light guide plate (50), and a reflective cover (41). The light guide plate includes a light incidence surface (51), a light-emitting surface (53) connecting with the light incidence surface, and a bottom surface (52) opposite to the light-emitting surface. The light source faces the light incidence surface. The reflective cover includes a reflective unit having two reflective surfaces (411, 412) defining a space with a bottom. The light source is accommodated in the bottom of the space. A cross-sectional profile of the reflective surfaces is defined by an equation in a polar coordinate ρ(φ). The equation is:{∫π/2φ-θρ(φ)sin(φ-θ)ⅆ(φ-θ)=∫0θ1cos2(θ)ⅆθρ(φ)=ρ0{cos(θ/2)/[cos(φ-θ)/2]}2, wherein, ρ represents a polar axis of the polar coordinate, φ represents a clockwise angle of the polar coordinate, and θ represents an anti-clockwise divergence angle of the light.