Backlight Module Cushion Pad Positioning for Light Guide Plate
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Solution Overview
Problem
Existing liquid crystal display (LCD) backlight modules face challenges in achieving uniform light extraction and power efficiency, particularly due to movement allowances and deformation issues in the light guide plate, which affect display brightness and reliability.
Innovation Solution
The proposed backlight module incorporates a light bar, a light guide plate with a reflective strip and cushion pads, and dams to ensure precise positioning and minimize movement allowances, combined with a bottom frame structure that includes a back plate and side walls, to enhance light extraction efficiency and reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the light guide plate is made flexible to accommodate assembly tolerances, then ease of assembly is improved, but positioning precision and light extraction uniformity deteriorate
Solution Approach 1:
The support structure is segmented into multiple cushion pads distributed at different positions on the light guide plate. Each cushion pad independently provides support and positioning, allowing the overall structure to accommodate tolerances while maintaining local positioning precision. The cushion pads are arranged in a segmented pattern that covers critical areas without requiring the entire plate to be rigid.
Solution Approach 2:
Different regions of the light guide plate are provided with different levels of support through strategically placed cushion pads. Areas requiring high positioning precision receive direct support from cushion pads, while other areas maintain flexibility. The cushion pads create localized rigid-supported zones that ensure light extraction uniformity without making the entire plate rigid.
2Manufacturing precision
If the light guide plate is rigidly fixed to ensure positioning precision, then positioning precision is improved, but light extraction uniformity and display quality deteriorate due to deformation
Solution Approach 1:
Cushion pads are pre-installed at critical positions on the light guide plate before final assembly. These cushion pads provide preemptive support to prevent deformation under operational loads. By placing cushion pads at strategically determined positions, the design anticipates and prevents potential deformation issues that would affect light extraction uniformity.
Solution Approach 2:
The support characteristics are adjusted by changing the parameters of the cushion pads, including their material hardness, thickness, and distribution pattern. These parameter changes allow the support structure to provide sufficient rigidity for positioning while maintaining flexibility to prevent deformation. The cushion pad parameters are optimized to balance positioning precision and light extraction uniformity.
3Manufacturing precision
If cushion pads are added to improve positioning and reduce deformation, then positioning precision and light extraction uniformity are improved, but device complexity increases
Solution Approach 1:
The cushion pads serve multiple functions simultaneously: they provide positioning support, prevent deformation, accommodate assembly tolerances, and distribute mechanical loads. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving multiple objectives.
Solution Approach 2:
The cushion pads are designed as thin, flexible elements that can be easily integrated into the existing light guide plate structure. Their flexible nature allows them to conform to slight variations in assembly while providing sufficient support. This approach adds minimal structural complexity compared to rigid support mechanisms.
4Reliability
If the number of cushion pads is increased to reduce deformation, then light extraction uniformity is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
Instead of uniformly distributing cushion pads across the entire light guide plate, the design applies cushioning support only at critical partial locations where deformation would most affect light extraction uniformity. This partial action approach achieves the necessary reliability improvement without the excessive cost and complexity of full-coverage cushioning.
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 ensures accurate positioning of the light guide plate, reduces deformation-related issues, and improves light extraction efficiency, leading to uniform display brightness and reduced power consumption, thereby enhancing the overall performance and reliability of the display device.
Implementation Method 1
The reflective strip is attached to the first side surface... the orthographic projection of the reflective strip on the first side surface
Implementation Method 2
Each cushion pad includes a first positioning portion and an avoiding portion... The first positioning portion is in surface contact with a portion of the first side surface
Data Source
AI summary
A backlight module includes a light bar, a light guide plate located on a light exit side of the light bar, a reflective strip, and at least two cushion pads. The light guide plate includes a first side surface away from the light bar. The reflective strip is attached to the first side surface. Each cushion pad includes a first positioning portion and an avoiding portion. An orthographic projection of the reflective strip on the first side surface is located outside an orthographic projection of the first positioning portion on the first side surface, and is partially overlapped with an orthographic projection of the avoiding portion on the first side surface. The first positioning portion is in surface contact with a portion of the first side surface that is non-covered by the reflective strip. The avoiding portion and the reflective strip have a first interval therebetween.