Backlight Assembly Thermal Expansion Compensation
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Solution Overview
Problem
Conventional edge illumination type backlight assemblies for LCD devices face challenges in maintaining a uniform incident light distance due to the elasticity of light guide plates, which affects light efficiency and reliability, as they contract or expand with temperature and moisture changes, leading to variations in light emission and display quality.
Innovation Solution
The implementation of a backlight assembly design that includes protrusions on the light source module's PCB and corresponding fixing grooves on the light guide plate, allowing for uniform maintenance of the incident light distance through thermal expansion and contraction, ensuring consistent light efficiency and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a light guide plate is used in an edge illumination type backlight assembly, then light can be guided from LEDs to the LCD panel, but the incident light distance varies due to thermal expansion and contraction of the light guide plate
Solution Approach 1:
The patent introduces a flexible connection structure between the light guide plate and the housing, allowing the light guide plate to dynamically adjust its position in response to thermal expansion and contraction. This dynamic adaptation maintains uniform incident light distance despite temperature changes, resolving the contradiction between light guidance functionality and distance uniformity reliability.
Solution Approach 2:
The patent modifies the physical parameters of the light guide plate by introducing flexible connection points and adjustable mounting structures. These parameter changes enable the light guide plate to accommodate thermal dimensional changes while maintaining consistent optical performance, addressing the reliability issue caused by thermal expansion and contraction.
2Loss of energy
If the incident light distance is not uniformly maintained, then light efficiency decreases, but adding rigid constraints may cause damage during thermal expansion
Solution Approach 1:
The patent employs flexible connection structures and thin-film mounting solutions that allow controlled movement and deformation of the light guide plate during thermal cycles. This flexibility maintains optimal incident light distance for high light efficiency while preventing structural damage, resolving the contradiction between energy efficiency and structural integrity.
Solution Approach 2:
The patent incorporates cushioning elements and compliant mounting structures that anticipate thermal expansion and contraction. These pre-designed flexible connections absorb thermal stresses before they can cause damage, while simultaneously maintaining the incident light distance within optimal ranges for sustained light efficiency.
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 design maintains a uniform incident light distance, enhancing light efficiency and reliability by accommodating thermal changes, thereby improving the consistency of light emission and display quality.
Implementation Method 1
The LGP then guides the light provided from the LEDS through the LGP such that the light is incident into the LCD panel
Implementation Method 2
The incident light distance is not uniformly maintained due to elasticity of the LGP, which may contract or expand in accordance with a surrounding temperature and moisture content of ambient air
Data Source
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AI summary
A backlight assembly includes a plurality of point light sources, a light guide plate ("LGP") and a printed circuit board ("PCB"). The LGP has a light incident face in which light is incident, a side surface extending from an edge portion of the light incident face, and a fixing groove which is formed from the side surface toward an inner portion thereof. The PCB includes a point light source disposing portion in which the point light sources are disposed along a first direction, an extending portion extending from the point light disposing portion along a second direction substantially perpendicular to the first direction, and a protrusion which is fixed at an end portion of the extending portion. The protrusion of the PCB is coupled with the fixing groove of the LGP.