Backlight Module Dual Grating Collimation and Thickness Reduction
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Solution Overview
Problem
Conventional backlight modules have limitations in achieving high collimation and uniformity of light emission, leading to suboptimal display performance and increased thickness.
Innovation Solution
The proposed backlight module incorporates a light source module with a transparent block and a first grating group, which diffracts initial lights to achieve higher collimation through a second grating group, utilizing semi-transparent films for uniform light emission, and a light guide plate with a light emergent and backlight surface configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional backlight modules are used, then the structure is simple, but the collimation degree and uniformity of light emission are insufficient
Solution Approach 1:
The backlight module is divided into multiple functional components: light source module, light guide plate, first grating group, and second grating group. Each component performs a specific function in the light path, allowing optimization of light collimation and uniformity through segmented control of light propagation stages.
Solution Approach 2:
The first grating group and second grating group are nested within the light guide plate structure. The gratings are positioned at different locations within the same optical path, creating a compact nested arrangement that achieves high collimation without proportionally increasing overall device volume.
2Illumination intensity
If conventional backlight modules are used, then the design is straightforward, but the module thickness is increased
Solution Approach 1:
The light propagation path is optimized by utilizing multiple dimensions within the light guide plate. The first grating group diffracts light in one dimension while the second grating group further collimates in the same dimension, achieving high uniformity without increasing thickness by stacking multiple layers in the vertical dimension.
Solution Approach 2:
The grating parameters (period, depth, orientation) are specifically designed and optimized to achieve the desired collimation and uniformity within a compact thickness. By adjusting grating parameters rather than adding more components, the design achieves high performance without increasing module thickness.
3Manufacturing precision
If high collimation is achieved through multiple diffraction stages, then display performance is improved, but the device complexity increases
Solution Approach 1:
The light guide plate serves multiple functions: it guides light from the light source, houses the first grating group for initial diffraction, contains the second grating group for final collimation, and provides structural support. This multi-functionality reduces the need for separate components, thereby improving display performance without proportionally increasing device complexity.
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 enhances the collimation degree and uniformity of light emitted from the backlight module, improving display performance while reducing module thickness.
Implementation Method 1
the first grating group is capable of diffracting the initial lights to obtain first diffracted lights
Implementation Method 2
controlling the first diffracted lights to be totally reflected in the light guide plate
Implementation Method 3
the second grating group is capable of diffracting the first diffracted lights to obtain second diffracted lights
Data Source
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AI summary
A backlight module and display device are provided. The backlight module includes: a light source module (01) and a light emergent module (02). The light source module (01) includes a transparent block (011), a light source (012) and a first grating group (013). The light emergent module (02) includes a light guide plate (021) and a second grating group (022). The light source (012) emits initial lights to the first grating group (013) diffracting initial lights to generate first diffracted lights, and controls the first diffracted lights to be totally reflected in the light guide plate (021) and transmitted to the second grating group (022); the second grating group (022) diffracts the first diffracted lights to generate second diffracted lights, and controls the second diffracted lights to be emergent from the backlight module. When an included angle between initial lights and side surface of light guide plate is greater than 0°, an included angle between second diffracted lights and side surface is smaller than an included angle between initial lights and side surface, thereby improving collimation degree of the lights emergent from backlight module.