Backlight Module Light Source Lens Alignment for LCD Efficiency
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Solution Overview
Problem
Existing ultra-thin LCD devices suffer from low light coupling efficiency and high light leakage due to misalignment of LEDs on printed circuit boards, which limits the number of LEDs and their driving power, and requires thinner light guide plates and LEDs, leading to inefficient power utilization.
Innovation Solution
A backlight module with a light guide plate and a light source featuring a metal core printed circuit board substrate with affixed LED chips, primary lenses, and condenser lenses, where the light source is positioned at a distance from the light guide plate, and includes a reflection sheet to enhance light coupling and utilization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If LED thickness is reduced to support ultra-thin LCD devices, then the overall device thickness is reduced, but light coupling efficiency decreases and light leakage increases
Solution Approach 1:
The patent introduces a light guiding layer as an intermediary component between the LED and light guide plate. This layer with specific refractive index (1.4-1.6) acts as a mediator to optimize light coupling, enabling thin LED design while maintaining high light coupling efficiency and preventing light leakage
2Length of stationary object
If LED thickness is reduced, then device thickness is reduced, but light leakage increases due to misalignment
Solution Approach 1:
The light guiding layer serves as a positioning intermediary that ensures precise alignment between the LED light emission face and the light guide plate. This mediator layer with controlled thickness and refractive index prevents light leakage caused by misalignment in ultra-thin configurations
3Device complexity
If the number of LEDs is limited due to lead frame constraints, then device complexity is reduced, but light utilization efficiency decreases
Solution Approach 1:
The patent changes the refractive index parameter of the light guiding layer (1.4-1.6) to optimize light extraction and utilization. This parameter adjustment enables efficient light coupling with fewer LEDs, improving light utilization efficiency without 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
The solution significantly improves light coupling efficiency, reduces light leakage, and enhances power utilization by ensuring proper alignment and focused light emission, allowing for higher LED density and increased brightness without heat constraints.
Implementation Method 1
Each primary lens is disposed correspondingly to a LED chip, focuses light from the LED chip
Implementation Method 2
Each condenser lens is disposed correspondingly to a primary lens to further narrow light emission angle of the LED chip
Implementation Method 3
The backlight module further includes a reflection sheet beneath the light guide plate and the light source
Data Source
AI summary
The present invention teaches a backlight module and the LCD device. The backlight module includes a light guide plate and a light source located at a distance to a side of the light guide plate. The light source includes a substrate, multiple LED chips disposed on the substrate, multiple primary lenses disposed on the substrate corresponding to the LED chips, and multiple condenser lenses disposed on the substrate corresponding to the primary lenses. Each primary lens is disposed correspondingly to a LED chip, focuses light from the LED chip, and prevents the light emission face of the LED chip from being higher above the light guide plate, thereby enhancing the light coupling efficiency and reducing leakage of the backlight module. Each condenser lens is disposed correspondingly to a primary lens to further narrow light emission angle of the LED chip, enhancing light utilization efficiency.