Thin Backlight Module With Diffusion-Based Mixing for Even Light
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Solution Overview
Problem
Existing backlight modules suffer from uneven light emission and excessive thickness, making them unsuitable for applications requiring high lightness and thinness, such as mobile devices.
Innovation Solution
A backlight module with a substrate, spot light sources, an optical conversion layer, and a light mixing member that includes phosphor and/or quantum dots, along with a light mixing member comprising diffusion powders and optical films to convert and mix light evenly, reducing the need for a large light mixing height and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a thick light guide plate is used to increase the transmission path length, then light emission evenness is improved, but the overall thickness of the backlight module increases
Solution Approach 1:
The patent replaces the traditional mechanical light guide plate with a light mixing member containing diffusion powders. This substitution eliminates the need for a thick light guide plate while achieving the same light mixing function through optical diffusion properties of the powders, thus reducing overall thickness while maintaining light emission evenness
Solution Approach 2:
The patent changes the light mixing mechanism from a geometric path length approach (thick light guide plate) to an optical diffusion approach (diffusion powders). By changing the physical parameter from thickness-based path length to particle-based optical diffusion, the system achieves effective light mixing in a thinner configuration
2Area of stationary object
If a direct-type backlight source with large-size interval lamp beads is used, then light emission coverage is improved, but the overall thickness increases due to required light mixing height
Solution Approach 1:
The patent replaces the mechanical prism structure with diffusion powders embedded in the optical conversion layer. This substitution eliminates the need for large light mixing height while achieving effective light distribution across the display area, thus reducing thickness while maintaining coverage
Solution Approach 2:
The patent merges the light conversion and light mixing functions into a single integrated optical conversion layer containing both phosphor particles and diffusion powders. This consolidation eliminates the need for separate light mixing components and reduces overall thickness while maintaining effective light emission coverage
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 provides even light emission with a reduced thickness, enabling full-screen display and high contrast in display screens and terminals, while also allowing for power-saving control and flexible or curved designs.
Implementation Method 1
a conversion layer including phosphor and/or quantum dots
Implementation Method 2
a conversion layer including phosphor and/or quantum dots
Implementation Method 3
the light mixing member comprises a plurality of diffusion powders exclusively distributed in the packaging layer and the protection layer and the light mixing member is configured to mix the light
Implementation Method 4
an optical membrane assembly located on a side that is of the conversion layer and that is away from the substrate and configured to mix and brighten passing light and comprising a first prism film, a diffusion film, and a second prism film
Data Source
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AI summary
Embodiments of this application disclose a backlight module, including a substrate, a plurality of spot light sources, an optical conversion layer, and a light mixing member. The plurality of spot light sources are fastened onto the substrate in a mutually spaced manner. The optical conversion layer is stacked on the substrate and covers the plurality of spot light sources. The optical conversion layer is configured to convert, into a white surface light source, light emitted by the plurality of spot light sources. The light mixing member is located on a surface of the optical conversion layer or embedded into the optical conversion layer. The light mixing member is configured to mix the light. The backlight module emits light evenly and has a relatively small thickness. The embodiments of this application further disclose a display screen and a terminal.