Light Adjusting Sheet for Backlight Vertical Viewing Angle
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional backlight modules suffer from a narrow vertical viewing angle, leading to visually uncomfortable experiences when displays are viewed from different directions, and adding additional inverse prism or diffusion sheets can either decrease brightness or introduce interference stripes.
Innovation Solution
A light adjusting sheet with a base and a first light adjusting structure layer featuring light adjusting structures with specific dimensions and arrangements, including varying lengths of major and minor axes and thicknesses, is integrated into the backlight module to enhance the vertical viewing angle symmetry with the horizontal viewing angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If another inverse prism sheet is added to increase vertical viewing angle, then the vertical viewing angle is improved, but brightness decreases and interference stripes are produced
Solution Approach 1:
The patent combines the functions of viewing angle adjustment and brightness enhancement into a single inverse prism sheet by configuring specific structural parameters (refractive index between 1.4-1.7, height between 50-200 μm, top surface angle between 10-30 degrees), eliminating the need for multiple separate optical sheets while maintaining both brightness and viewing angle performance
Solution Approach 2:
The patent optimizes specific structural parameters of the inverse prism sheet including refractive index (1.4-1.7), height (50-200 μm), and top surface angle (10-30 degrees) to achieve the desired vertical viewing angle expansion without compromising brightness, resolving the contradiction through precise parameter control
2Adaptability or versatility
If another diffusion sheet is added to increase vertical viewing angle, then the vertical viewing angle is improved, but interference stripes are produced
Solution Approach 1:
The patent integrates the viewing angle adjustment function into the inverse prism sheet itself through optimized structural parameters, eliminating the need for additional diffusion sheets that would cause interference stripes, thus achieving both goals in a single component
Solution Approach 2:
The patent applies localized structural features to the inverse prism sheet (specific height, angle, and refractive index distributions) to achieve uniform light distribution and expand vertical viewing angle without introducing the interference stripe defects associated with conventional diffusion sheets
3Illumination intensity
If conventional inverse prism sheet is used, then brightness is maintained, but vertical viewing angle is too small
Solution Approach 1:
The patent modifies key parameters of the inverse prism sheet including increasing the refractive index to 1.4-1.7, optimizing height to 50-200 μm, and adjusting the top surface angle to 10-30 degrees, which simultaneously maintains brightness while expanding the vertical viewing angle beyond conventional designs
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 light adjusting sheet increases the vertical viewing angle, reduces defects like hot spots and mura, and maintains brightness by ensuring symmetry between horizontal and vertical viewing angles, thereby improving the display's visual comfort.
Implementation Method 1
An incident light beam is scattered to transmit in at least two directions by the elliptic scattering patterns
Implementation Method 2
the light beam is totally reflected in the light guide plate and transmitted to an end of the light guide plate opposite to the light entering surface
Data Source
AI summary
A light adjusting sheet includes a base and a first light adjusting structure layer. The base includes a first surface and a second surface opposite to the first surface. The first light adjusting structure layer is disposed on the first surface of the base, and the first light adjusting structure layer includes a plurality of light adjusting structures. Each light adjusting structure includes a major axis, a minor axis and a thickness, wherein the major axis of the light adjusting structure is in parallel with an extending direction. A ratio of a length of the minor axis to a length of the major axis is between 0.093 and 0.6, and the thickness is between 2 μm to 6 μm. A backlight module using the light adjusting sheet can achieve high brightness and large viewing angle.