Backlight Light Path Control Element for Display Luminance Uniformity
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Solution Overview
Problem
The challenge is to improve image quality in display devices while reducing the thickness of the backlight unit without increasing the number of light sources, as a sufficient optical gap between the light source and the display panel is not formed, leading to degraded image quality.
Innovation Solution
A backlight unit is designed with light sources on a printed circuit and a light path control element featuring engraved patterns on both surfaces, along with a light conversion film having diffusion patterns, to enhance light diffusion and maintain image quality by adjusting the light path and increasing the distance between light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the thickness of the backlight unit is reduced, then the thickness of the display device is reduced, but a sufficient optical gap between the light source and the display panel is not formed, leading to degraded image quality
Solution Approach 1:
The patent introduces a light path control element with three-dimensional engraved patterns that manipulate light propagation in multiple dimensions. The engraved patterns create micro-cavities and refractive structures that redirect and diffuse light paths, effectively increasing the optical interaction distance without increasing the overall thickness of the backlight unit. This dimensional manipulation of light paths resolves the contradiction between thin profile and sufficient optical gap.
Solution Approach 2:
The light path control element acts as an intermediary component between the light source and the display panel. It includes engraved patterns that serve as light-manipulating structures to create sufficient optical path length and diffusion. This intermediary element enables the system to maintain image quality while reducing overall thickness, as it mediates the optical interaction without requiring a large physical gap.
2Device complexity
If the number of light sources in the backlight unit is reduced, then the complexity and cost are reduced, but image quality and luminance uniformity are degraded
Solution Approach 1:
The patent extracts the light diffusion and path control functions from the light sources themselves and places them in a dedicated light path control element. By separating these functions, fewer light sources are needed, as the light path control element with its engraved patterns and light conversion film performs the diffusion and uniformity distribution that would otherwise require multiple light sources to achieve.
Solution Approach 2:
The light path control element serves multiple functions simultaneously: it controls light paths, diffuses light, converts light wavelengths, and ensures luminance uniformity. This multi-functional component replaces what would traditionally require multiple separate light sources and optical elements, thereby reducing device complexity while maintaining image quality.
3Manufacturing precision
If engraved patterns are added to the light path control element, then light diffusion and path control are improved, but manufacturing complexity increases
Solution Approach 1:
The patent optimizes the parameters of the engraved patterns, such as depth, width, spacing, and shape, to achieve effective light diffusion and path control. By carefully selecting these parameters, the patterns can be manufactured using standard precision molding or etching techniques, balancing manufacturing feasibility with optical performance. The parameters are tuned to ensure that the complexity is justified by the significant improvement in light diffusion.
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
This solution effectively improves image quality and luminance uniformity while reducing the thickness of the backlight unit by optimizing light diffusion and reducing the number of light sources, thereby enhancing the overall performance of the display device.
Implementation Method 1
a light path control element located over one or more of the plurality of light sources, including a plurality of first engraved patterns each located in an area overlapping with all or at least a part of each of the plurality of light sources
Implementation Method 2
including a plurality of second engraved patterns located in one or more areas except for areas overlapping with the plurality of light sources on a bottom surface of the light path control element
Implementation Method 3
a light conversion film located on the light source protective element and including a light diffusion layer disposed on a lower portion of the light conversion film and a plurality of light diffusion patterns disposed on an upper portion of the light conversion film
Data Source
AI summary
Embodiments of the present disclosure relates to a light path control element, a backlight unit and a display device, and by disposing, over one or more light sources, a light path control element including a first engraved patterns located on a surface through which light exits and located to correspond to respective light sources, and a second engraved patterns located on a surface into which light is incident and located in an areas between light sources, it is possible to improve functions of guiding and diffusing light emitted from the light sources. Accordingly, by increasing a distance between light sources and enabling a hot spot to be prevented and luminance uniformity to improve, it is possible to reduce the number of light sources and provide a backlight unit producing improved image quality.