Backlight Module Light Mixing Layer Reduces Mixture Distance
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Solution Overview
Problem
Current liquid crystal display backlight technologies, particularly the direct-emitting type, face challenges in reducing light mixture distance, leading to thickness issues that make them unsuitable for mobile devices, as they require a long light mixture distance and are difficult to make thin.
Innovation Solution
A backlight module comprising a backplane with a light reflecting surface, a light source layer with point light sources, and light mixing components that include a light reflecting layer and a light transmission layer, along with a light diffusion structure, to reduce light mixture distance and enhance light output uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a direct-emitting type backlight structure uses point light sources, then light emitting brightness can be controlled point by point based on image brightness, but brightness in vertical direction is much greater than in surrounding region and a relatively long light mixture distance is required
Solution Approach 1:
The patent introduces a light mixing layer positioned between the point light sources and the display panel, creating an additional dimensional space for light redistribution. This layer receives light from point sources in one dimension and redistributes it across the surface in another dimension, converting vertical light intensity concentration into lateral light distribution, thereby reducing the required light mixture distance while maintaining uniform illumination.
Solution Approach 2:
The light mixing layer serves as an intermediary component between the point light sources and the display panel. It mediates the light transmission process by receiving concentrated light from point sources, mixing it through scattering and diffusion mechanisms, and then delivering uniform light to the display panel, thus resolving the contradiction between point source efficiency and uniformity requirements.
2Length of stationary object
If a direct-emitting type backlight structure is used to reduce light mixture distance, then thickness can be reduced, but uniformity of light output across the display surface deteriorates
Solution Approach 1:
The light mixing layer creates an intermediate dimensional space that enables light redistribution without increasing overall backlight thickness. By positioning this layer strategically within the existing thickness budget, the patent achieves lateral light mixing that improves uniformity while maintaining the reduced thickness advantage.
Solution Approach 2:
The patent modifies the optical parameters of the light mixing layer, including its thickness, refractive index, and scattering properties, to optimize the balance between light mixing effectiveness and overall structure thickness. By adjusting these parameters, the system achieves uniform light output without requiring excessive thickness.
3Length of stationary object
If a side-emitting type backlight structure is used, then the structure becomes light and thin, but all LED light sources must be always turned on to ensure uniform light output
Solution Approach 1:
The patent enables dynamic control of point light sources, allowing individual LEDs to be turned on or off based on the actual image content requirements. This dynamic switching capability transforms the static illumination approach of side-emitting backlights into a dynamic system that can adjust power consumption while maintaining uniformity through the light mixing layer's optical redistribution.
Solution Approach 2:
The patent implements local quality control by enabling independent control of point light sources in different regions of the display. Each point light source can be activated only when needed for specific image regions, allowing the system to maintain uniform light output where required while conserving energy in regions where point-by-point control is not needed.
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 allows for more uniform light emission and reduces the thickness of the backlight structure, making it suitable for mobile devices by minimizing the light mixture distance and improving light output uniformity.
Implementation Method 1
a light reflecting layer configured to reflect some light rays emitted by a corresponding point light source
Implementation Method 2
a light transmission layer configured to transmit a light ray reflected by the light reflecting layer and then reflected again by the light reflecting surface
Implementation Method 3
The light diffusion structure is disposed on at least one of a light input surface and a light output surface of the light transmission layer, to improve light output uniformity of the light transmission layer
Data Source
Figure 1~3a
Figure 3b~4
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AI summary
This application provides a backlight module, a display, and a mobile terminal. The backlight module mainly includes three parts: a backplane having a light reflecting surface, a light source layer disposed on the light reflecting surface, and at least one light mixing component disposed on the light source layer. The light source layer has at least one point light source, and the at least one light mixing component is in a one-to-one correspondence with the at least one point light source. Each light mixing component includes a light reflecting layer configured to reflect some light rays emitted by a corresponding point light source, and a light transmission layer configured to transmit a light ray reflected by the light reflecting layer and then reflected again by the light reflecting surface. The light reflecting layer is disposed above the light source layer and is configured to reflect the some light rays emitted by the corresponding point light source. The light reflecting layer reflects the some light rays emitted by the point light source, and the some light rays are reflected again by the light reflecting surface on the backplane and then emitted from the light transmission layer. In this way, the light rays are more uniformly emitted from the backlight module, and a light mixture distance of the backlight structure is reduced.