Light Guide Plate Inclined Angles for Edge-Lit LCD Brightness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional edge-light-type liquid crystal display devices with LED backlights face challenges in achieving uniform surface brightness due to non-uniform light distribution and increased manufacturing costs, particularly when using multiple prism or diffusion sheets.
Innovation Solution
A liquid crystal display device design featuring a light guide plate with inclined surfaces, where the angle of the inclined surfaces near the light source is larger than those farther away, and a refractive index of 1.53 or less, combined with a light diffusion sheet and an asymmetric prism sheet, to optimize light distribution and reduce the number of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If multiple prism sheets or light diffusion sheets are used to make surface brightness uniform, then surface brightness uniformity is improved, but device thickness increases and manufacturing cost increases
Solution Approach 1:
The patent combines the light diffusion function and light guiding function into a single integrated light guide plate structure. The light guide plate incorporates both the diffusion sheet's light scattering capability and the prism sheet's light directing capability, eliminating the need for separate diffusion sheets and prism sheets. This merging reduces the number of components while maintaining uniform surface brightness.
Solution Approach 2:
The light guide plate is designed to perform multiple functions simultaneously: it guides light from the edge source, diffuses light to achieve uniform brightness distribution, and directs light toward the display panel. This multi-functional design replaces what would traditionally require separate diffusion sheets and prism sheets, reducing device complexity.
2Illumination intensity
If multiple prism sheets or light diffusion sheets are used to make surface brightness uniform, then surface brightness uniformity is improved, but device thickness increases
Solution Approach 1:
The patent combines the light diffusion function and light guiding function into a single integrated light guide plate structure. The light guide plate incorporates both the diffusion sheet's light scattering capability and the prism sheet's light directing capability, eliminating the need for separate diffusion sheets and prism sheets. This merging reduces the number of components while maintaining uniform surface brightness.
3Ease of manufacture
If LED light sources are arranged along the light incident surface, then light emitting points are scattered, but light does not spread in many directions making surface brightness non-uniform
Solution Approach 1:
The light guide plate incorporates localized varying structures (such as varying prism angles or groove densities) at different positions to compensate for the non-uniform light distribution from scattered LED sources. Areas closer to LED sources have different optical structures compared to areas farther away, creating local variations that achieve overall 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
This configuration allows for uniform surface brightness and reduced component count, enhancing the efficiency and cost-effectiveness of the backlight system while maintaining directional control of light emission.
Implementation Method 1
The light guide plate is formed using a light transmitting resin, for example. Light which is incident on the light guide plate from the light source propagates in the light guide plate.
Implementation Method 2
Reflecting/scattering members such as grooves, projections or prints are formed on the light guide plate. Light which propagates in the light guide plate is reflected or scattered by the reflecting/scattering members, and is radiated toward a liquid crystal display device side.
Implementation Method 3
the light guide plate has a first main surface and a second main surface which faces the first main surface in an opposed manner, the second main surface has a plurality of inclined surfaces
Implementation Method 4
the inclined surfaces are formed such that an angle of the inclined surface positioned near the light source and an angle of the inclined surface positioned remote from the light source differ from each other
Data Source
AI summary
A liquid crystal display device which can make the surface brightness of an edge-light-type backlight uniform is provided. The liquid crystal display device includes a liquid crystal display panel and a backlight which radiates light to the liquid crystal display panel. The backlight includes a light guide plate which is arranged on a back side of the liquid crystal display panel, a light source arranged on an outer peripheral portion of a first main surface of the light guide plate which faces the liquid crystal display panel in an opposed manner, and a reflection sheet which is arranged on a back side of the light guide plate as viewed from the liquid crystal display panel. The light guide plate is made of a transparent resin having a refractive index of 1.53 or less. On a surface of the light guide plate opposite to the first main surface, a second main surface which is substantially parallel to the first main surface and a plurality of inclined surfaces which are inclined at a preset angle with respect to the second main surface are formed. An angle of the inclined surface positioned near a position at which light from the light source is incident and an angle of the inclined surface positioned remote from the position at which the light from the light source from the light source is incident differ from each other.