Backlight Module Curved Grooves Virtual Light Sources
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Solution Overview
Problem
Conventional backlight modules for liquid crystal displays suffer from poor light source uniformity due to the distribution of cold cathode fluorescence lamps, leading to increased thickness and reduced brightness.
Innovation Solution
A direct-type backlight module with a light box featuring parallel grooves and reflective curved surfaces, where real light sources are positioned on alternate focal points of elliptic profiles, creating virtual light sources to enhance light distribution and density, combined with a diffusion plate and optical film for improved uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If cold cathode fluorescence lamps are distributed in the light box, then light source coverage is improved, but light source uniformity deteriorates
Solution Approach 1:
The light box bottom is segmented into multiple parallel grooves with reflective curved surfaces. Each groove acts as an independent optical channel that guides and reflects light from real light sources to create virtual light sources, thereby segmenting the light distribution path to achieve better uniformity across the entire light box area.
Solution Approach 2:
The reflective curved surfaces in each groove create virtual light sources that are optical copies of the real light sources. These virtual light sources are positioned at specific locations (light source allocation lines) to supplement the real light sources, effectively doubling the light source density and improving uniformity without adding physical light sources.
2Illumination intensity
If distance between light box bottom and diffusion plate is increased, then light beam spread is improved, but module thickness increases
Solution Approach 1:
The grooves are designed with curved reflective surfaces (elliptical or parabolic profiles) that actively guide and redirect light beams. This curvature enables the light to spread and mix more effectively over a shorter distance compared to a flat bottom, achieving the required light beam spread while maintaining a compact module thickness.
Solution Approach 2:
The reflective curved surfaces act as optical intermediaries between the real light sources and the diffusion plate. They mediate the light propagation by reflecting and redirecting light beams, enabling sufficient light mixing and uniformity to be achieved at reduced distances, thereby allowing thinner module design.
3Illumination intensity
If light source density is increased, then light source uniformity is improved, but device complexity increases
Solution Approach 1:
The groove structures are merged with the light box bottom, and the reflective surfaces are integrated into the groove walls. This merging eliminates the need for separate reflective components, reducing assembly steps and structural complexity while achieving the desired light distribution and uniformity enhancement.
Solution Approach 2:
The grooves with reflective curved surfaces serve multiple functions: they guide light from real sources, create virtual light sources, control light beam spread, and define light source allocation lines. This multi-functionality reduces the need for additional components, thereby reducing overall device complexity while improving light source uniformity.
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 achieves a more uniform and brighter plane light source with reduced module thickness by increasing light source density and optimizing light beam spread, thereby enhancing the overall display performance.
Implementation Method 1
A part of light emitted from each of the real light sources is reflected by the reflective curved surface to the light source allocation lines on which the real light sources are not disposed, so as to form a plurality of virtual light sources
Data Source
AI summary
A backlight module includes a light box and multiple real light sources. The light box has an opening and a plurality of substantially parallel grooves recessed from a bottom surface thereof. Each of the slots has a reflection curved surface. A light source allocation line is defined between every two adjacent grooves. The light source allocation lines are parallel to the grooves. The sum of shortest distances between any point of the reflection curved surface and the two adjacent light source allocation lines is substantially the same. In addition, the real light sources are alternately allocated in the light source allocation lines. A part of light emitted from each light source is reflected from the reflection curved surface to the light source allocation line in which no light source is allocated. Thereby, a virtual light source is formed on the light source allocation line that does not contain a real light source.