Backlight Module Diffusely Reflecting Layers Light Mixing Uniformity
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Solution Overview
Problem
Mainstream backlight modules suffer from light mixing nonuniformity, leading to varying brightness across a visible area, which affects the overall display effect, especially when displaying a white screen with 255 gray levels.
Innovation Solution
A backlight module is designed with a plurality of lamp sources, a fluorescent film, and diffusely reflecting layers positioned in the light emission direction, where the first diffusely reflecting layer is placed above the lamp sources and the second above or integrated into the fluorescent film, along with a filter film between the lamp source and fluorescent film to enhance light uniformity and prevent longer wavelength light from being absorbed by the drive substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If film layer structures such as diffusion film and prismatic lens are arranged in light emission direction, then light effect and light mixing uniformity within certain viewing angle range are improved, but light mixing nonuniformity within visible area still occurs causing brightness nonuniformity
Solution Approach 1:
The patent divides the backlight module into multiple independent light emitting regions by arranging multiple lamp sources (LEDs) in an array configuration. Each lamp source creates a localized light emitting region, and the overall visible area is segmented into multiple sub-regions corresponding to each lamp source. This segmentation allows for better control and distribution of light across the entire visible area, improving brightness uniformity.
Solution Approach 2:
The patent applies different optical properties to different regions of the backlight module. Specifically, it uses lamp sources with different spectral characteristics (first lamp source emitting first light, second lamp source emitting second light) in different regions. Additionally, the filter film is selectively positioned between certain lamp sources and the fluorescent film to allow only specific wavelengths to pass through in certain regions, creating local quality variations that improve overall light mixing uniformity across the visible area.
2Loss of energy
If filter film is arranged between lamp source and fluorescent film, then longer wavelength light is prevented from being absorbed by drive substrate, but device complexity increases
Solution Approach 1:
The patent introduces a filter film as an intermediary component positioned between the lamp source and the fluorescent film. This filter film selectively transmits certain wavelengths of light while blocking others, acting as a mediator that controls which light reaches the fluorescent film and which is reflected back to the drive substrate. This prevents energy loss from longer wavelength light being absorbed by the drive substrate while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent changes the optical parameters (wavelength transmission characteristics) of the light path by introducing the filter film. The filter film is designed with specific spectral transmission properties that allow it to selectively pass certain wavelengths while blocking others, thereby changing the wavelength composition of light reaching different components and preventing unwanted absorption by the drive substrate.
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 diffusely reflecting layers ensure uniform light distribution and mixing, improving brightness uniformity and light emission quality by scattering light to a larger range and preventing unwanted wavelengths from being absorbed, thereby enhancing the display effect.
Implementation Method 1
The diffusely reflecting layer arranged above the fluorescent film scatters light emitted from the fluorescent film, scatters the light and distributes the light to a larger range
Implementation Method 2
The filter film allows the first primary color light having a shorter wavelength to pass through to reflect the second primary color light and the third primary color light having a longer wavelength
Data Source
AI summary
The present disclosure discloses a backlight module and a display device. The light emission direction of at least one of the lamp source and the fluorescent film is provided with a diffusely reflecting layer. The diffusely reflecting layer arranged above the lamp source diffusely reflects pump light emitted from the lamp source, which may enhance uniformity of the pump light. The diffusely reflecting layer arranged above the fluorescent film scatters light emitted from the fluorescent film, scatters the light and distributes the light to a larger range, which may improve light mixing uniformity and improve the uniformity of light emission brightness.